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Tabe Yutaka

Faculty of Engineering　Mechanical and Aerospace Engineering　Thermal and Fluid SystemsProfessor
Institute for Academic InnovationProfessor

Researcher basic information

■ Degree
  • 博士（工学）, 東京工業大学
■ URL
researchmap URLホームページURL■ Various IDs
Researcher number
  • 80374578
ORCID IDJ-Global ID■ Research Keywords and Fields
Research Keyword
  • 固体高分子形燃料電池
  • 物質移動
  • 二次電池
  • エネルギーシステム解析
Research Field
  • Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering), Thermal engineering
■ Educational Organization

Career

■ Career
Career
  • Apr. 2019 - Present
    北海道大学 大学院工学研究院, 教授, Japan
  • Apr. 2022 - Mar. 2025
    The University of Tokyo, 教授（委嘱）, Japan
  • Apr. 2007 - Mar. 2019
    北海道大学 工学(系)研究科(研究院), 准教授
  • Apr. 2004 - Mar. 2007
    北海道大学 工学(系)研究科(研究院), 助教授
  • Apr. 2000 - Mar. 2004
    株式会社荏原製作所
  • Apr. 1997 - Mar. 2000
    日本学術振興会, 特別研究員
Educational Background
  • Apr. 1997 - Mar. 2000, Tokyo Institute of Technology, Science of Engineering, Mechanical Engineering Science
  • Apr. 1995 - Mar. 1997, Tokyo Institute of Technology, Science of Engineering, Mechanical Engineering Science
  • Apr. 1991 - Mar. 1995, Tokyo Institute of Technology, School of Engineering
Committee Memberships
  • Apr. 2024 - Mar. 2025
    日本機械学会, 熱工学部門 学会賞委員会 委員長, Society
  • Apr. 2022 - Mar. 2023
    日本機械学会, 熱工学部門 年鑑委員会 委員長, Society
  • Apr. 2021 - Mar. 2023
    日本機械学会, 動力エネルギーシステム部門 シンポジウム企画委員会 幹事, Society
  • May 2020 - May 2022
    日本伝熱学会, 理事, Society
  • Apr. 2019 - Mar. 2020
    日本機械学会, 熱工学部門 熱工学コンファレンス委員会 委員長, Society
  • May 2017 - May 2019
    日本伝熱学会, 学生会委員会 委員長, Society
  • Apr. 2016 - Mar. 2017
    日本機械学会, 熱工学部門 講習会委員会 委員長, Society
  • Feb. 2011
    比布町, 比布町地域省エネルギービジョン策定委員会 委員長, Autonomy
  • Jun. 2009 - May 2010
    日本伝熱学会, 伝熱シンポジウム実行委員会 幹事, Society
  • May 2008 - May 2010
    日本伝熱学会, 理事, Society

Research activity information

■ Awards
  • Nov. 2024, スマートプロセス学会, Best Review Paper賞
    物質輸送、熱輸送から考える高出力化のための電池構造
    田部 豊;植村 豪;境田 悟志
  • Mar. 2021, 日本機械学会, 熱工学部門 貢献表彰
    田部 豊
  • Apr. 2020, 日本機械学会, 日本機械学会賞（論文）
    Scale model experiments for evaluation of liquid water transport in the gas diffusion layer of PEFCs
    Yutaka TABE;Satoshi SAKAIDA;Takemi CHIKAHISA
  • May 2000, 日本伝熱学会, 奨励賞
    田部 豊
■ Papers
■ Other Activities and Achievements
■ Books and other publications
  • マイクロ・ナノ熱工学の進展
    田部 豊; 境田 悟志, 第2編 第12章 第2節，PP.368－373
    エヌ・ティー・エス, May 2021, [Joint work]
  • Micro & Nano-Engineering of Fuel Cells
    T. Chikahisa; Y. Tabe, Section 1: Pore-scale water transport investigation for polymer electrolyte membrane (PEM) fuel cells, PP.1－35
    CRC Press, 2015, [Joint work]
■ Lectures, oral presentations, etc.
  • Flow Field Structure for Improving Start-up Performance and Power Output in Non-Humidified High-Temperature PEFC
    Shion Omura; Ryosuke Ichikawa; Yusuke Aoyama; Suguru Uemura; Yutaka Tabe
    ECS Meeting Abstracts, 24 Nov. 2025
    24 Nov. 2025 - 24 Nov. 2025
  • Low-Dimensionalization Experiments on Porous Cathodes and Analysis of Oxygen Transport and Reaction Distributions Toward High-Power Lithium-Air Batteries
    Shoki Sasaki; Yusuke Aoyama; Suguru Uemura; Yutaka Tabe
    ECS Meeting Abstracts, 24 Nov. 2025
    24 Nov. 2025 - 24 Nov. 2025
  • Overpotential Characteristic and Flow Field Structure for High Power Output of HT-PEFC
    Ryosuke Ichikawa; Ryo Sakakibara; Shion Omura; Yusuke Aoyama; Suguru Uemura; Yutaka Tabe
    ECS Meeting Abstracts, 22 Nov. 2024
    22 Nov. 2024 - 22 Nov. 2024
  • Enhancement of Liquid Water and Oxygen Transport By Partially Hydrophilic Mpls in a PEFC
    Yuya Tanaka; Yusuke Aoyama; Suguru Uemura; Yutaka Tabe
    ECS Meeting Abstracts, 22 Nov. 2024
    22 Nov. 2024 - 22 Nov. 2024
  • Study on PEFC Ionomer-Free Catalyst Layer for Reduction of Oxygen Transport Resistance Developed by Electrospray
    MATSUSHITA Yuki; OKANO Masaya; UEMURA Suguru; TABE Yutaka
    The Proceedings of the National Symposium on Power and Energy Systems, 2024, The Japan Society of Mechanical Engineers, Japanese
    2024 - 2024, One of the problems of polymer electrolyte fuel cells (PEFCs) is its high cost due to the use of platinum for catalyst layer (CL). We tried to reduce the amount of the platinum by using graphene without ionomer. The graphene-based CL is expected to eliminate the oxygen transport resistance through the ionomer. This is because the graphene has the potential to conduct both of protons and electrons. The previous study by the authors suggested that the power output of a single cell with ionomer-free CL is higher than that with conventional ketjen black-based CL with the ionomer under the lower platinum usage conditions, while the quality and power generation performance of the CL were not stable. In this study, we attempted to improve the platinum loading density (wt%) by changing the temperature control method and the amount of chemicals used in the CL fabrication. The experimental results showed that the quality and power generation performance of the CL become stable. The power generation performance improved as the amount of platinum used increased, which was consistent with the results of the oxygen transport resistance analysis.
  • Enhancing the High Power Output of Lithium Air Battery with Nafion Coated Cathode Considering O2 and Li+ Transport Characteristics
    Nishimori Shuma; Aoyama Yusuke; Uemura Suguru; Tabe Yutaka
    The Proceedings of the Thermal Engineering Conference, 2024, The Japan Society of Mechanical Engineers, Japanese
    2024 - 2024, Lithium-air batteries have attracted attention because of their high theoretical energy density. However, due to the low solubility and diffusivity of oxygen in the electrolyte, oxygen transport to the cathode reaction site is limited. In this research, a thin layer of lithiated-Nafion was formed on the cathode and its discharge performance was evaluated. Thinning the Nafion layer reduces oxygen transport resistance; however, the impact on lithium transport resistance needs to be considered. In order to to obtain a cathode structure that achieves high power output, discharge tests and one-dimensional model analysis were conducted.
  • Effect of Electrolyte Distribution on Discharge Performance of Lithium-Air Battery Cathodes
    UEMURA Suguru; HIROSE Haruto; SAYEM A.S.M.; TABE Yutaka
    The Proceedings of the National Symposium on Power and Energy Systems, 2024, The Japan Society of Mechanical Engineers, Japanese
    2024 - 2024, Lithium-air battery attracts great attention because of its high energy density. However, due to the low solubility and diffusivity of oxygen in the electrolyte, oxygen transport to the cathode reaction site is limited. In this study, the effect of electrolyte distribution in the porous cathode on discharge performance was investigated. A small cell consisting of a cathode, an anode, and a reference electrode was used. Discharge tests were conducted with different electrolyte distributions in the cathode. As a result, the highest performance was obtained under conditions of partial wet condition. The electrolyte was injected into the electrode using a syringe pump, and the injected volume was less than half of the pore volume. It is thought that the discharge performance was improved because a wide reaction area was formed while the oxygen transport path was maintained in the porous cathode.
  • Evaluation of Ionomer SPR Properties and its Humidity Dependence for Analysis of Transport Phenomena in PEFC Catalyst Layers
    SAITOU Hideto; UEMURA Suguru; TABE Yutaka
    The Proceedings of Mechanical Engineering Congress, Japan, 2024, The Japan Society of Mechanical Engineers, Japanese
    2024 - 2024, Ionomer used in the catalyst layer of polymer electrolyte fuel cells (PEFCs) acts as a transport path for protons, but it also causes resistance of the oxygen transport. Therefore, ionomer is one of the key components to achieve high performance PEFCs. However, their structure and properties have not been fully understood. In this study, surface plasmon resonance (SPR) imaging was applied to investigate the ionomer characteristics. SPR is a phenomenon in which a sparse wave of free electrons couples with an electromagnetic field and propagates along a plane on a metal surface deposited on a substrate such as glass. Since the excitation and resonance conditions strongly depend on the nanoscale state of the metal surface, the surface nanoscale structure can be imaged and quantified by investigating the SPR characteristics. First, very thin Nafion film was prepared by spin coating on gold surface deposited on a glass substrate. Then, based on the measured SPR characteristics, the ionomer film thickness was estimated to be 10.7 nm. Further, SPR observation under controlled humidity was developed, and it was confirmed that the swelling of ionomer due to humidity change can be evaluated by the SPR measurement.
  • Analysis of Effective Measures of Surplus Electricity from Variable Renewable Energy by Introduction of EVs and FCVs in Hokkaido
    MATSUBA Koki; UEMURA Suguru; TABE Yutaka
    The Proceedings of the National Symposium on Power and Energy Systems, 2024, The Japan Society of Mechanical Engineers, Japanese
    2024 - 2024, Since the power output of variable renewable energies (VREs) depends on weather conditions, it is difficult to supply electricity according to demand. The introduction of a large amount of VREs will result in excess power plant capacity to meet electricity demand, increasing costs associated with power generation and power plant capacity, etc. Therefore, it is important to reduce wasted electricity. One effective way to use surplus electricity is to utilize it for automobile traffic. In this study, we analyzed the optimal power supply configuration and cost reduction effects by utilizing surplus power from the massive introduction of VREs for electric vehicles (EVs) and hydrogen production power for fuel cell vehicles (FCVs). Adding the demand for hydrogen from FCVs as well as EVs demand can reduce the overall cost of the system by effectively utilizing the surplus electricity from the increased share of VREs after 50%. Optimizing EVs recharging and hydrogen filling leads to reductions in power plant capacity and storage battery installation, effective use of the facilities in each region, and contributing to the reduction of excess electricity.
  • Flow Field Structure for Improving Start-up and Power Output of Non-Humidification High-Temperature PEFC
    OMURA Shion; ICHIKAWA Ryosuke; AOYAMA Yusuke; UEMURA Suguru; TABE Yutaka
    The Proceedings of Mechanical Engineering Congress, Japan, 2024, The Japan Society of Mechanical Engineers, Japanese
    2024 - 2024, Polymer Electrolyte Fuel Cell (PEFC) has high energy conversion efficiency because it can directly convert chemical energy into electrical energy, and discharges only water during the power generation, which reduces the environmental impact. Fuel Cell Vehicles (FCVs) are being developed and deployed in commercial vehicles, such as large trucks and buses, to further popularize them in the future. To improve power generation efficiency and reduce the load on the cooling system, it is necessary to increase the operating temperature (aiming for up to 180°C). One of main advantages of the higher operating temperatures compared to conventional PEFC is the larger temperature difference from the ambient temperature, which improves cooling capacity and allows for higher load operation. In this study, we conducted experimental investigations and improvements on the flow field structure of non-humidification high-temperature PEFC. The objective is to reduce concentration overvoltage at high temperature operations and to actively discharge water generated during startup from low temperatures. In the experiment, three types of flow field were used. The pressure and temperature dependence of IV characteristics under high temperature conditions and the oxygen transport resistance at low temperature were investigated. The results showed that an interdigitated flow field has excellent high-temperature IV characteristics, where a 0.5mm straight flow field was the most suitable for discharging generated water at the low temperature.
  • Performance Analysis of Non-Humidified High-Temperature PEFC by Fuel Cell System Simulator
    Ryosuke Ichikawa; Ryo Sakakibara; Suguru Uemura; Yutaka Tabe
    ECS Meeting Abstracts, 22 Dec. 2023
    22 Dec. 2023 - 22 Dec. 2023
  • Proposal and Fundamental Investigation of Energy Storage and Hydrogen Supply System Using the Lithium
    Suguru Uemura; Shuntaro Ikegami; Yutaka Tabe
    ECS Meeting Abstracts, 22 Dec. 2023
    22 Dec. 2023 - 22 Dec. 2023
  • Study on Fabrication Method of Ionomer-Free Catalyst Layer and Increase in Power Output of PEFC
    Matsushita Yuki; Okano Masaya; Uemura Suguru; Tabe Yutaka
    The Proceedings of the Thermal Engineering Conference, 2023, The Japan Society of Mechanical Engineers, Japanese
    2023 - 2023, A fabrication method of the PEFC ionomer-free catalyst layer (CL) is developed. In the CL, the ionomer is removed, and instead proton-conducting graphene is used. It was confirmed by the previous study that this CL have high power output in the lower Pt range. However, the output characteristics changes varied depending on temperature and humidity during the fabrication process, and the reproducibility is insufficient. This study aims to improve the reproducibility and the power output by examining the fabricating conditions.
  • Polarization characteristics of non-humidified high-temperature PEFC
    SAKAKIBARA Ryo; ICHIKAWA Ryosuke; UEMURA Suguru; TABE Yutaka
    The Proceedings of Conference of Hokkaido Branch, 2023, The Japan Society of Mechanical Engineers, Japanese
    2023 - 2023, A polymer electrolyte fuel cell (PEFC) attracts attention as the next generation of high efficiency energy conversion system due to their excellent starting performance and compact size. In the future, Fuel cell electric vehicles (FCEVs) are being deployed and developed for commercial vehicles, and further output improvement is required for further popularization. Meanwhile, as output increases, the amount of heat generated also increases, so the upper temperature limit of the PEFC must be improved to improve cooling efficiency. The recently developed high-temperature polymer electrolyte membrane fuel cell (HT-PEFC), which uses a high-temperature polymer electrolyte membrane (HT-PEM) that can be used non-humidified and high-temperature conditions, is being considered to solve the operating temperature conditions. While the HT-PEM can generate electricity at higher temperatures, the limiting current density values and power output are small compared to the power generation characteristics of the FCs currently installed in FCEVs. In this study, we evaluate the contribution to the polarization that is dominant in HT-PEFCs, especially the concentration polarization due to the decrease in oxygen concentration caused by high temperatures, by changing the operating conditions. In order to conduct the experiments, we fabricated a device for high-temperature power generation and selected a spring that can maintain a constant surface pressure in order to keep the experimental conditions constant. In addition, we operated the PEFC and evaluated its performance. As a result, generally normal performance was obtained, slightly inferior to the nominal performance of the HT-PEM, but comparable at high current densities.
  • Effects of Adding Large Size Pores to MPL on Condensed Water Distribution and Oxygen Transport Resistance Components in a PEFC
    FUJII Katsuhiro; UEMURA Suguru; TABE Yutaka
    The Proceedings of Mechanical Engineering Congress, Japan, 2023, The Japan Society of Mechanical Engineers, Japanese
    2023 - 2023, To increase the power output of polymer electrolyte fuel cells (PEFCs), careful water management is important, and a micro-porous layer (MPL) suppresses water accumulation near the catalyst layer (CL). This study applied the MPL added with larger size pores to promote the water removal, and investigated the effecs using the extended limiting current analysis developed by the authors. In this method, the increase in oxygen transport resistance due to water accumulation is separated into pressure-dependent and -independent components by introducing two indices determining the condensed water effects. The components approximately correspond to the transport resistances outside and inside of the CL respectively. The results showed that adding larger size pores reduces increases in the oxygen transport resistance under flooded conditions. The extended limiting current analysis revealed that the suppression in the resistance increases is mainly caused by smaller pressure-dependent component. Further, the observation of water distributions by a freezing method and cryo-SEM indicated that condensation of produced water in the large pores inhibits that in the normal pores.
  • Effect of I/C on Oxygen Transport Resistances in the Catalyst Layers and through the Ionomer in a PEFC
    NAKANO Yusuke; UEMURA Suguru; TABE Yutaka
    The Proceedings of the National Symposium on Power and Energy Systems, 2023, The Japan Society of Mechanical Engineers, Japanese
    2023 - 2023, Reducing the amount of platinum catalysts used in a polymer electrolyte fuel cell is indispensable for the widespread use of FCV. In the previous study by the authors, the oxygen transport resistance of the cathode catalyst layer (CL) has been analyzed in detail to realize efficient oxygen supply. The oxygen transport resistance in the CL was classified into two types: diffusion resistance in the CL pores, which is proportional to the CL thickness, and resistance through the ionomer, which is related to the Pt surface area. This study tried to evaluate the effects of I/C and platinum usage on the oxygen transport resistances. First, to reduce variability in the oxygen transport resistance separation, thickness control of the GDL after assembling was conducted by introducing spacers, and it was confirmed that proper separation of oxygen transport resistance is possible. Then, it was suggested that the coating speed of CL ink in the fabrication process affects the microstructure of fabricated CL and further improvement is required.
  • Effect of Cathode Structure and Wettability on Discharge Characteristics of Lithium-Air Batteries
    Hirose Haruto; Uemura Suguru; Tabe Yutaka
    The Proceedings of the Thermal Engineering Conference, 2023, The Japan Society of Mechanical Engineers, Japanese
    2023 - 2023, Lithium-air battery attracts great attention because of its high energy density. However, due to the low solubility and diffusivity of oxygen in the electrolyte, oxygen transport to the reaction site of the positive electrode is limited. In this study, we focused on the effects of the porous cathode structure and wettability of the electrolyte on discharge performance, and attempted to increase the effective reaction area in the electrode and reduce oxygen transport resistance. As a result, it was observed that the discharge performance significantly varies depending on the formation of the electrolyte thin film and the partial infiltration of the electrolyte into the porous electrode.
  • Effect of Operation Conditions on Current Density Distribution in Interdigitated Flow Fields of Redox Flow Battery
    Kameda Tomohiro; Uemura Suguru; Tabe Yutaka
    The Proceedings of the Thermal Engineering Conference, 2023, The Japan Society of Mechanical Engineers, Japanese
    2023 - 2023, The effects of flow path structure of a redox flow battery on the discharge performance and the current density distribution were investigated. From the current density distribution measurements, it was confirmed that an interdigitated design (IDD) has a very small bias in the current density distribution upstream and downstream, and that the flow rate has a very small effect on the current density distribution in constant voltage operation, as compared with a flow-through design (FTD). The performance analysis showed that this may be due to the larger value of the surface concentration overpotential due to the slower flow velocity in the IDD.
  • Improving Drainage in PEFCs by Hybrid MPLs with Hydrophilic Fibers Added
    TANAKA Yuya; UEMURA Suguru; TABE Yutaka
    The Proceedings of the National Symposium on Power and Energy Systems, 2023, The Japan Society of Mechanical Engineers, Japanese
    2023 - 2023, Improving the ability to manage produced water is an important issue in increasing the power output of polymer electrolyte fuel cell (PEFC). In this study, a hydrophobic microporous layer (MPL) is used in PEFC to drain produced water. We fabricated a hybrid MPL by adding hydrophilic fibers to hydrophobic MPL, and investigated the effects of the hybrid MPL on the power generation performance and cold startup characteristics. When the fibers in the hybrid MPL were shorter than the thickness of the MPL, the breakthrough pressure was lower than that of the hydrophobic MPL, and the power generation performance was lower. This is thought that if the fibers are short, the liquid water stays around the fibers and inhibits the diffusion of oxygen. On the other hand, when the fibers were longer than the thickness of the MPL, the breakthrough pressure was slightly lower than that of the hydrophobic MPL, and the power generation performance was improved. This is thought to be because the fibers penetrating the MPL act as hydrophilic pathways that drain liquid water effectively. In the cold startup test using the hybrid MPLs with short fibers, an insulation cell was used to simulate a stack by using insulation material. Although we succeeded in starting up from -3°C, there was a decrease in performance after the output power increased. This is estimated to be due to larger amount of water accumulated during the cold startup.
  • Imaging of Interfacial Phenomena at Nafion Using Surface Plasmon Resonance
    SAITOU Hideto; UEMURA Suguru; TABE Yutaka
    The Proceedings of Conference of Hokkaido Branch, 2023, The Japan Society of Mechanical Engineers, Japanese
    2023 - 2023, Polymer electrolyte fuel cell (PEFC) are expected to be the next generation of high-efficiency energy conversion devices. In a PEFC, a thin film (several nm thick) of polymer electrolyte (typically Nafion) in the catalyst layer is responsible for transporting protons, while it also hinders oxygen transport. Therefore, the Nafion thin film is an important component to achieve high performance, but their structure and formation process are still not fully understood. In this study, we evaluate the structure and properties of Nafion using a surface plasmon resonance (SPR) imaging system. The results of the observation of pure water drops on the gold surface showed that the bright and dark areas between the gold-droplet interface region and the gold-atmosphere interface region were visible. Also, observation of the drying process of Nafion dispersion solution (film formation) showed that an agglomeration occurred. Then, a spin-coater deposition was applied as a uniform Nafion deposition method. In addition, as a preliminary step to observe the Nafion film when potential is applied during a power generation, the effect of potential application on the SPR observation was investigated.
  • Power increase of lithium-air batteries by formation of a thin electrolyte film inside a porous cathode
    HIROSE Haruto; UEMURA Suguru; TABE Yutaka
    The Proceedings of Conference of Hokkaido Branch, 2023, The Japan Society of Mechanical Engineers, Japanese
    2023 - 2023, Lithium-air battery attracts great attention because of its high energy density. However, due to the low solubility and diffusivity of oxygen in the electrolyte, oxygen transport to the reaction site of the positive electrode is limited. In this study, experiments using glassy carbon were conducted while changing the contact angle and contact area with the electrolyte in order to shorten the distance of oxygen transport to the electrolyte by thinning the electrolyte covering the reaction surface. As a result, when the electrolyte contact area changed, the thin electrolyte film was formed and the discharge performance was improved.
  • Investigation of Temperature and Humidity Dependency of Ionomer SPR Characteristics toward Evaluation of Transport Phenomena in Catalyst Layers
    Saitou Hideto; Uemura Suguru; Tabe Yutaka
    The Proceedings of the Thermal Engineering Conference, 2023, The Japan Society of Mechanical Engineers, Japanese
    2023 - 2023, Ionomer used in the catalyst layer of polymer electrolyte fuel cells (PEFCs) acts as a transport path for protons, but it also causes resistance in the transport of oxygen. Therefore, ionomer is one of the essential components for achieving high performance PEFC. However, their structure and properties have not been fully elucidated. In this study, we conducted experiments and improved the experimental setup to perform Surface Plasmon Resonance (SPR) measurements on nanoscale ionomer films formed on a substrate. We aimed to carry out these measurements under conditions where film thickness, the surrounding humidity, and temperature were varied.
  • Effect of Channel Structure in Redox Flow Battery on Current Density Distribution
    KAMEDA Tomohiro; UEMURA Suguru; TABE Yutaka
    The Proceedings of Conference of Hokkaido Branch, 2023, The Japan Society of Mechanical Engineers, Japanese
    2023 - 2023, The effects of flow path structure of a redox flow battery on the discharge performance were investigated, and the cause of the performance difference were examined by measuring the current density distribution. It was confirmed from the current density distribution measurements that the current density decreases at down streams in the interdigitate designs, and that the current density distribution increases with lower SOC and higher average current density. It was confirmed that the effect of flow rate on the current density distribution was very small. This is presumably due to the fact that the average current density increases as the flow rate increases, which may counteract the improvement in performance that results from increasing the flow rate. I plan to measure the current density distribution by changing the electrolyte flow rate at the same average current density. The goal is to elucidate the relationship between the performance and the flow path structure by comparing the results with those of FTD.
  • Effects of Accumulated Water on Cell Performance and Mechanism of the Drainage after PEFC Cold Startup
    Mukai Makoto; Uemura Suguru; Tabe Yutaka
    The Proceedings of the Thermal Engineering Conference, 2023, The Japan Society of Mechanical Engineers, Japanese
    2023 - 2023, For cold startup of a polymer electrolyte fuel cell (PEFC), rapid output increase after the temperature rise is a critical issue. This study investigated the effective operating conditions for this issue. In the experiments, an adiabatic cell was used to simulate the temperature rise of the stack. Flooding occurred after the startup from 4 ℃ with the stoichiometry of 2.5, while dehydration occurred after the sub-zero startup and power increase with the cell from -3 ℃ with the stoichiometry of 5.0. These indicate that the flow rates of supply gases largely affect the accumulation of liquid water.
  • Development of PEFC Low Pt-Loading Graphene Catalyst Layer By Electrospray Method for Increasing Output Power
    Masaya Okano; Suguru Uemura; Yutaka Tabe
    ECS Meeting Abstracts, 09 Oct. 2022
    09 Oct. 2022 - 09 Oct. 2022
  • Effects of MPL Pore Size Distribution on Components of Oxygen Transport Resistance Increased Due to Water Accumulation in a PEFC
    Katsuhiro Fujii; Suguru Uemura; Yutaka Tabe
    ECS Meeting Abstracts, 09 Oct. 2022
    09 Oct. 2022 - 09 Oct. 2022
  • Effects of Accumulated Water on Power Increase after PEFC Cold Startup
    MUKAI Makoto; UEMURA Suguru; TABE Yutaka
    The Proceedings of the National Symposium on Power and Energy Systems, 2022, The Japan Society of Mechanical Engineers, Japanese
    2022 - 2022, For cold startup of a polymer electrolyte fuel cell (PEFC), rapid output increase after the temperature rise is a critical issue. This study investigated experimentally the effective cell structure for this issue. In the experiment, we used an adiabatic cell to simulate the temperature rise of the stack by using separators with a small heat capacity and insulation material around it. The sub-zero startup with the cell with 1.0 mm wide channel and rib was successful from –10 ℃, but the shutdown occurred immediately due to flooding after the load increase. In the power increase with 0.3 mm wide channel and rib, it was shown that the cell voltage with 0.3mm wide channel and rib becomes more stable after the load increase than with the 1.0 mm wide channel and rib. This indicates that the narrow rib and channel is effective to improve the rapid power increase after the cold startup. This is considered because the liquid water is less likely to accumulate at the interface between MPL and CL in the cell with 0.3 mm wide channel and rib.
  • Analysis of Effective Use of Surplus Electricity in Transportation Sectors with Large-Scale Introduction of Variable Renewable Energy in Hokkaido
    KATO Hiroki; UEMURA Suguru; TABE Yutaka
    The Proceedings of the National Symposium on Power and Energy Systems, 2022, The Japan Society of Mechanical Engineers, Japanese
    2022 - 2022, Wind and solar power generations are attracting attention as a countermeasure to global warming, but the output fluctuations occur in their large-scale introduction. This paper analyzes how to mitigate the output fluctuations of these variable renewable energies (VREs) in Hokkaido. In the analysis, the output patterns of 20 wind and 10 solar powers were set by the hour, and the total annual cost was calculated to be the minimum using a linear programming. If a large amount of variable renewable energy is introduced, a surplus of electricity is generated even with the introduction of countermeasures for output fluctuation. In this paper, EVs and FCVs were introduced as an effective way to use surplus power. In the case with EVs, the results showed that surplus power can be reduced by about 70% with no restrictions. The total annual cost in the FCV case is relatively higher, but becomes lower than that in the EV case given the constraint of a full charge at 4:00 am with the VRE share higher than 60%. In the range of VREs share below 20% and above 70%, it is cost effective to produce hydrogen in each region, and in the range of 30~60%, it is cost effective to transport hydrogen from northern Hokkaido to central Hokkaido.
  • Reduction of Oxygen Transport Resistance of Lithium-Air Battery Cathode by using Ionomer
    TSUKAMOTO Masahiro; UEMURA Suguru; TABE Yutaka
    The Proceedings of the National Symposium on Power and Energy Systems, 2022, The Japan Society of Mechanical Engineers, Japanese
    2022 - 2022, Lithium-air battery attracts great attention because of its high energy density. However, due to the low solubility and diffusivity of oxygen in the electrolyte, oxygen transport to the reaction site of the positive electrode is limited. The aim of this study is to reduce the oxygen transport resistance and increase the power output by using thin solid electrolyte membranes (ionomer). It is thought that ionomers can form a thin solid electrolyte film, which is difficult with liquid electrolytes, and can reduce oxygen transport resistance. The ionomer produced by coating the cathode with lithiated Nafion solution and drying. In this study, the effect of ionomer coating was investigated by conducting discharge experiments using cathodes with and without ionomer coating, respectively. Experimental results showed that performance was improved by using ionomer. Additionally, it was also suggested that the water content of the ionomer can affect the discharge performance.
  • Bubble formation behavior in hydrogen supply system using lithium metal
    IKEGAMI Shuntaro; UEMURA Suguru; TABE Yutaka
    The Proceedings of the National Symposium on Power and Energy Systems, 2022, The Japan Society of Mechanical Engineers, Japanese
    2022 - 2022, When a lithium-air battery is discharged, lithium ions normally react with oxygen at the positive electrode, but when the positive electrode potential drops significantly, water in the electrolyte reacts with lithium ions to generate hydrogen. In this study, we proposed a new system for high-density energy storage and hydrogen supply using lithium by utilizing the structure of lithium-air batteries and this working principle, and conducted basic experiments. As a result, it was confirmed that a large overvoltage is involved for the hydrogen production reaction compared to the theoretical potential. In addition, the formation behavior of hydrogen bubbles was observed, and it was confirmed that the almost spherical bubbles were generated in this experimental system. In the future, we will investigate the detailed causes of the overvoltage and hydrogen production behavior in the hydrogen production reaction and propose methods to reduce the overvoltage in order to improve the efficiency of hydrogen production.
  • Effects of Condensed Water on Oxygen Transport Resistance Components Separated By the Limiting Current Analysis in PEFC
    Yutaka Iizuka; Yuki Kitami; Suguru Uemura; Yutaka Tabe
    ECS Meeting Abstracts, 19 Oct. 2021, The Electrochemical Society, English
    19 Oct. 2021 - 19 Oct. 2021
  • Experimental Evaluation of PEFC Catalyst Layer Structure to Reduce Oxygen Transport Resistances
    Shu Mizuno; Suguru Uemura; Yutaka Tabe
    ECS Meeting Abstracts, 19 Oct. 2021, The Electrochemical Society, English
    19 Oct. 2021 - 19 Oct. 2021
  • Development of the surface plasmon resonance imaging and observation of the polymer film formation
    TANI Kosuke; UEMURA Suguru; TABE Yutaka
    The Proceedings of Conference of Hokkaido Branch, 2021, The Japan Society of Mechanical Engineers, Japanese
    2021 - 2021
  • Visualization of Condensed Water at the MPL/Catalyst Layer Interface in a Polymer Electrolyte Fuel Cell
    藤井克裕; 飯塚友俊; 植村豪; 田部豊
    日本機械学会動力・エネルギー技術シンポジウム講演論文集(CD-ROM), 2021
    2021 - 2021
  • Leveling technology of grid balance for large- scale installation of wind and solar power in Hokkaido
    Biness Lukwesa; Wataru Sato; Yutaka Tabe; Takemi Chikahisa
    ECOS 2020 - Proceedings of the 33rd International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems, 2020, ECOS 2020 Local Organizing Committee, English
    2020 - 2020
  • Water Transport in PEFC Cold Startup with Temperature Rise Simulating Adiabatic Condition
    Ken Hirai; Yutaka Tabe
    ECS Meeting Abstracts, 01 Sep. 2019, The Electrochemical Society
    01 Sep. 2019 - 01 Sep. 2019
  • Effect of Electrode Structure and Electrolyte Flow on Performance of Redox Flow Battery
    Sota Osanai; Yutaka Tabe; Takemi Chikahisa
    ECS Meeting Abstracts, 01 Sep. 2019, The Electrochemical Society
    01 Sep. 2019 - 01 Sep. 2019
  • Development of Graphene-Based PEFC Catalyst Layer for Reduction of Oxygen Transport Resistance
    Keisuke Yada; Yutaka Tabe
    ECS Meeting Abstracts, 01 Sep. 2019, The Electrochemical Society
    01 Sep. 2019 - 01 Sep. 2019
  • Water Transport in Gas Diffusion Layer of PEFC with Wettability Distribution in Thickness Direction
    Satoshi Sakaida; Kotaro Tanaka; Mitsuru Konno; Yutaka Tabe
    ECS Meeting Abstracts, 01 Sep. 2019, The Electrochemical Society
    01 Sep. 2019 - 01 Sep. 2019
  • Analysis of Oxygen Transport Resistances in the Catalyst Layers with Different Carbon Supports in PEFC
    Takayasu Satake; Yutaka Tabe; Takemi Chikahisa
    ECS Meeting Abstracts, 23 Jul. 2018, The Electrochemical Society, English
    23 Jul. 2018 - 23 Jul. 2018
  • Experimental Study on the Balance between Microscopic Water Production and Temperature Rise During Cold Startup in PEFC
    Fumito Onishi; Yutaka Tabe; Takemi Chikahisa
    ECS Meeting Abstracts, 23 Jul. 2018, The Electrochemical Society, English
    23 Jul. 2018 - 23 Jul. 2018
  • Study on PEFC Gas Diffusion Layer with Designed Wettability Pattern Tolerant to Flooding
    Satoshi Sakaida; Yutaka Tabe; Takemi Chikahisa; Kotaro Tanaka; Mitsuru Konno
    ECS Meeting Abstracts, 23 Jul. 2018, The Electrochemical Society
    23 Jul. 2018 - 23 Jul. 2018
  • Experimental Analysis of Oxygen Transport Resistance for Different Types of Ionomer in PEFC Catalyst
    Takumi Iiri; Yutaka Tabe; Takemi Chikahisa
    ECS Meeting Abstracts, 23 Jul. 2018, The Electrochemical Society
    23 Jul. 2018 - 23 Jul. 2018
  • Analysis of power generation structure, cost, and CO2 emission for massive introduction of wind and solar power in Hokkaido, and the effect of electricity use in transportation
    岡田季樹; 田部豊; 近久武美
    日本機械学会動力・エネルギー技術シンポジウム講演論文集(CD-ROM), 2018, Japanese
  • 北海道における大幅なCO2排出削減に向けた長期的な最適エネルギー導入技術解析
    藤原貴弘; 田部豊; 近久武美
    エネルギーシステム・経済・環境コンファレンス講演論文集(CD-ROM), 2018, Japanese
  • PEM形燃料電池の昇温過程における氷点下起動特性
    大西史人; 田部豊; 近久武美
    日本機械学会北海道支部講演会講演概要集(CD-ROM), 18 Sep. 2017, Japanese
  • 北海道における風力・太陽光発電の大量導入に向けた変動対策および水素変換技術の導入解析
    岡田季樹; 田部豊; 近久武美
    日本機械学会北海道支部講演会講演概要集(CD-ROM), 18 Sep. 2017, Japanese
  • 家庭用小型吸着式冷凍機のための吸脱着を伴う熱物質移動現象に関する研究
    浅川夏越; 田部豊; 近久武美
    日本機械学会北海道支部講演会講演概要集(CD-ROM), 18 Sep. 2017, Japanese
  • トータルエンジンシミュレータ用のディーゼル燃焼モデルに関する研究
    坂井拓也; 田部豊; 近久武美
    日本機械学会北海道支部講演会講演概要集(CD-ROM), 18 Sep. 2017, Japanese
  • PEFCカソード触媒層における酸素輸送抵抗の支配因子
    佐竹孝保; 田部豊; 近久武美
    日本機械学会北海道支部講演会講演概要集(CD-ROM), 18 Sep. 2017, Japanese
  • PEM形燃料電池触媒層における白金の高効率利用に関する研究
    飯利拓実; 田部豊; 近久武美
    日本機械学会北海道支部講演会講演概要集(CD-ROM), 18 Sep. 2017, Japanese
  • Analysis of Oxygen Transport Resistance Components and Water Transport Phenomena with Hydrophilic and Hydrophobic MPL in PEFC
    Ryo Nozaki; Yutaka Tabe; Takemi Chikahisa; Toshihiro Tanuma
    ECS Meeting Abstracts, 01 Sep. 2017, The Electrochemical Society
    01 Sep. 2017 - 01 Sep. 2017
  • Experimental Evaluation of Dominant Transport Resistances of Oxygen in Catalyst Layers of PEFC
    Yutaka Tabe; Takayasu Satake; Takumi Iiri; Tomoya Hayashi; Takemi Chikahisa
    ECS Meeting Abstracts, 01 Sep. 2017, The Electrochemical Society
    01 Sep. 2017 - 01 Sep. 2017
  • Effect of Cost Reduction in Power Sources on Large-Scale Penetration of Wind and Solar Power in Hokkaido
    Kengo Suzuki; Naoya Takahashi; Yutaka Tabe; Takemi Chikahisa
    2017 INTERNATIONAL CONFERENCE ON GREEN ENERGY AND APPLICATIONS (ICGEA 2017), 2017, IEEE, English
    2017 - 2017, This study focuses on the power supply system of Hokkaido, the largest and northernmost prefecture in Japan and identifies the barriers to raise the share of wind and solar power to 100%. An increase in total system cost versus the penetration of wind and solar power into the energy system was examined based on the current technology and cost level. The effect of cost reductions in solar power and batteries are also investigated. The results show that the share of wind and solar power can be raised to 50% without significant increase in the total system cost. To achieve this, wind power should mainly be installed in the northern area and transmission lines should be enhanced to connect the northern and capital areas. However, the profitability of non-renewable power decreases with increasing wind power capacity. As the share of renewables exceeds 50%, the total system cost rapidly increases because of a widening of the demand-supply gap. Reducing the cost of solar power can reduce the total system cost to some extent. However, the main power source is still wind energy because the seasonal pattern of wind power output is in higher correlation with demand than solar power.
  • 親水性カーボンファイバーMPLによる固体高分子形燃料電池のフラッディング改善メカニズム
    青山祐介; 鈴木研悟; 田部豊; 近久武美; 田沼敏弘
    日本伝熱シンポジウム講演論文集(CD-ROM), 2016
    2016 - 2016
  • PEFCにおける触媒層内酸素輸送抵抗と水輸送メカニズム解析
    野崎涼; 青山祐介; 鈴木研悟; 田部豊; 近久武美
    日本機械学会動力・エネルギー技術シンポジウム講演論文集(CD-ROM), 2016
    2016 - 2016
  • 産業連関分析によるコジェネレーション導入が及ぼす地域経済波及効果
    長沼要; 鈴木研悟; 田部豊; 近久武美
    日本機械学会動力・エネルギー技術シンポジウム講演論文集(CD-ROM), 2016
    2016 - 2016
  • Study on method for analyzing oxygen transport resistance components in PEFC under flooding conditions
    NOZAKI Ryo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2016, The Japan Society of Mechanical Engineers, Japanese
    2016 - 2016
  • Relationship between ice formation and electric resistance change in cathode catalyst layer during cold startup of PEFC
    KASAI Futa; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2016, The Japan Society of Mechanical Engineers, Japanese
    2016 - 2016
  • Characteristics of current density distribution and performance at high current density operation in redox flow battery
    ZENTO Tetsuya; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2016, The Japan Society of Mechanical Engineers, Japanese
    2016 - 2016
  • Analysis of long-term energy system configuration for the effective reduction of greenhouse gas in Hokkaido
    FUJIWARA Takahiro; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2016, The Japan Society of Mechanical Engineers, Japanese
    2016 - 2016
  • Monolayer Graphene for proton exchange membrane and catalyst layer in PEM fuel cells
    Kumar Abhay; Tabe Yutaka; Chikahisa Takemi
    The Proceedings of Conference of Hokkaido Branch, 2016, The Japan Society of Mechanical Engineers, English
    2016 - 2016
  • Study on cell structures for higher efficiency and higher current density of redox flow batteries
    SAKAMOTO Atsushi; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2016, The Japan Society of Mechanical Engineers, Japanese
    2016 - 2016
  • 親水性MPLを有する固体高分子形燃料電池の発電および生成水分布特性
    青山祐介; 鈴木研悟; 田部豊; 近久武美; 田沼敏弘
    日本伝熱シンポジウム講演論文集(CD-ROM), 2015
    2015 - 2015
  • Pore-scale water transport investigation for polymer electrolyte membrane (PEM) fuel cells
    Takemi Chikahisa; Yutaka Tabe
    Micro and Nano-Engineering of Fuel Cells, 01 Jan. 2015
    01 Jan. 2015 - 01 Jan. 2015, © 2015 Taylor & Francis Group, London, UK. Polymer electrolyte membrane (PEM) fuel cells could potentially become promising power sources for vehicles and stationery combined heat and power (CHP) generators in the near future, as they have higher efficiency and cleaner emission characteristics than conventional engines. Although hydrogen fuel for the cells is mainly produced from natural gas with a conversion efficiency of around 75% at present, well-to-wheel efficiency is still superior to conventional engines. When hydrogen is produced from renewable energy sources, such as solar cells and windmills, PEM fuel cells will be the most powerful devices to convert hydrogen into power with the highest efficiency.
  • REMOVAL OF SHAPE DEFORMATION IN THE FREE ENERGY BASED LATTICE BOLTZMANN METHOD FOR LARGE DENSITY RATIO
    Jia-ming Gong; Nobuyuki Oshima; Yutaka Tabe
    PROCEEDINGS OF THE ASME 13TH INTERNATIONAL CONFERENCE ON NANOCHANNELS, MICROCHANNELS, AND MINICHANNELS, 2015, 2015, AMER SOC MECHANICAL ENGINEERS, English
    2015 - 2015, The free energy based lattice Boltzmann method (LBM) for two-phase flow with large density ratio is used to simulate droplet dynamics in the polymer electrolyte fuel cell (PEFC). The shape deformation of a static water droplet in the gas channel occurred in the simulations was eliminated. In this LBM model, two types of staggered grids which respectively make use of the velocity components from the orthogonal and diagonal directions are blended to calculate the hydrodynamic pressure from the Poisson equation, with the successive over relaxation method (SOR). It is found that the simulated water droplet shape is determined by both the blending factor of the two types of staggered grids and the radius length. The appropriate blending factor for each radius length is summarized to optimize the simulation. The dependence of shape deformation on the blending factor and the radius length is further validated while considering the wettability effect of the solid wall of the gas channel. It is proved that the summarized appropriate blending factors are still practical when the concept of equivalent radius length is adopted.
  • E225 Analysis of changing energy structures and total costs for medium to long-term CO_2 reduction targets in Hokkaido
    Yanagi Yusuke; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of the National Symposium on Power and Energy Systems, 2015, Japanese
    This study analyzes an influence of CO_2 reduction target on the energy mix and energy supply cost of Hokkaido until the 2050. As the target becomes more aggressive, the energy supply cost increases mainly in the power generation sector, and the increase in power generation cost is mainly caused by the substitution of fossil fuel fired power with wind power. When the larger amount of wind power is installed, the mismatch between demand and supply increases mainly in the summer and interphase, and the larger amount of surplus electricity need to be discarded.
  • D122 Ice Formation Behavior at Cold Start with Supercooled Water in PEFC
    ISHIMA Yuta; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of the National Symposium on Power and Energy Systems, 2015, Japanese
    At cold startup of a polymer electrolyte fuel cell PEFC at -10 ℃, the produced water remains as supercooled water before it freezes, and then the shutdown occurs with ice layer formation between the cathode catalyst layer (CL) and micro-porous layer (MPL). This study investigated ice formation behavior during the cold startup with supercooled water in PEFC by measurements of cold start characteristic and observations of the cathode CL using a Cryo-SEM. The ice layer observed at the interface became thicker gradually during the startup, and this suggested that the produced water moves through ionomer in the CL. Basic investigation of the water transport through the ionomer and its driving force was conducted, and introduction of a hydrophilic MPL was tested to improve the cold start characteristics, longer startup period.
  • C131 Effect of Electrolyte Flow Condition on Charge-Discharge Efficiency in Redox Flow Battery
    SHIMADA Ryo; UCHIYAMA Masamichi; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of the National Symposium on Power and Energy Systems, 2015, Japanese
    In vanadium redox flow battery, energy efficiency decreases mainly because of ohmic loss IR_ and concentration overpotential η_. Especially capacity loss by early shutdown timing of charge and discharge process is strongly affected by η_, which depends on mass transfer of active species to reaction area. In this study, we conducted charge-discharge experiments with a single cell battery in order to investigate the behavior of cell voltage around shutdown and elucidate the relationship between mass transfer coefficient k and electrolyte flow condition. It was shown that that the k is proportional to 0.5〜0.6th power of mean electrolyte flow velocity ν, and the coefficients are different for the charge and discharge processes.
  • S0830302 Influence of regional characteristics, cost, and technological development on the performance of distributed cooperative CHP system
    AKAZAWA Masayuki; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Mechanical Engineering Congress, Japan, 2015, Japanese
    The authors proposed the concept that CHPs, which is combined heat and power and sometimes called co-generation, are installed to buildings with large heat demand and excessively generated electricity is consumed in buildings in the grid network. The analysis demonstrated significant effect of the system for the reduction of CO_2 with keeping cost advantage, compared to the non-networked CHPs. This paper analyses dependence of the effect on regions, CHP devices, and cost conditions. The results show that the networked CHP system keeps its significant effect even in Tokyo area, although the effect is larger in Sapporo. Compared to the non-networked system, CO_2 can be reduced twice by the networked CHPs. This is due to the fact that houses have high heat/electricity demand ratio even in Tokyo. The paper also shows the effectiveness of fuel cell CHPs compared to gas-engines, due to higher efficiency of electric generation. Cost analysis indicates that the supply unit cost ratio of grid electricity and town gas linearly influences the cost benefit of CHPs.
  • J0560103 Influence of porous structure in PEFC with metal foam flow field on cell performance and water transport
    YAEHARA Motoki; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Mechanical Engineering Congress, Japan, 2015, Japanese
    According to earlier studies, the porous flow fields of Polymer Electrode Fuel Cell (PEFC) are more tolerant against flooding phenomenon in comparison with conventional flow channels such as straight and serpentine type channels. However, the relationship between the porous structure and water management ability of porous media has not been clarified. This study investigated the influence of porosity and pore diameter of metal foam flow fields on the cell performance and water transport. Celmets, which are the porous media with foam structure and high porosity in comparison with sintered metal, is used as the porous flow fields. The results show that the influence of pore diameter on cell performance and water drainage is small under the condition of this study. And the usage of celmets with higher porosity, 96.8%, causes a decrease in cell performance. Such a performance decrease appears to be caused by the lower contact pressure and inferior gas diffusion.
  • J0560101 High-Speed LBM Simulation of Condensed Water Behavior in PEFC Gas Diffusion Layers
    AZUMA Takeshi; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Mechanical Engineering Congress, Japan, 2015, Japanese
    In PEFC, flooding phenomena is one of the critical problems to be solved. Therefore, it is necessary to optimize water and reactant gas flow management in the cell. Our research group applied the lattice Boltzmann method (LBM) for the two phase flow with high density ratio, including the effect of wettability, and has carried out the analyses of gas and liquid water flow to propose the gas diffusion layer (GDL) with the high water draining capability. In this study, we simulated liquid water behavior inside of the GDL applying the equal density LBM in order to achieve shorter computational time comparing to the high density ratio LBM. In the equal density LBM code developed by the authors, we found two problems. One was a decrease in amount of water in the GDL, and the other was discriminating liquid water behavior compared with in the high density ratio LBM. This paper explains the applied improvements to solve these two problems by setting the wall boundary conditions appropriately.
  • G0110103 Effect of Free-out Outlet Boundary Condition on the Free Energy Based Two-Phase Flow LBM with Large Density Ratio
    Jiaming GONG; OSHIMA Nobuyuki; Tabe Yutaka
    Mechanical Engineering Congress, Japan, 07 Sep. 2014, The Japan Society of Mechanical Engineers, English
    07 Sep. 2014 - 07 Sep. 2014, The effect of 0-velocity inlet and free-out outlet boundary condition used in the free energy based LBM with large density ratio was investigated in this paper. A static water droplet in the quiescent gas in a gas channel was simulated with both the 0-velocity inlet and free-out outlet boundary condition and the periodic boundary conditions along Z direction of the computational domain. The total mass loss was observed while using the 0-velocity and free-out outlet boundary condition. By comparing with results from the periodic boundary condition, it was proved that both the velocity inlet and the free-out outlet can be the sources of mass un-conservation; the difference of the simulation results between the two types of boundary conditions are small, both boundary conditions can be used in the target simulation.
  • Effect of Wettability of Micro-Porous Layer on Microscopic Water Transport Phenomena in PEFC
    Yusuke Aoyama; Kengo Suzuki; Yutaka Tabe; Takemi Chikahisa; Toshihiro Tanuma
    ECS Meeting Abstracts, 05 Aug. 2014, The Electrochemical Society
    05 Aug. 2014 - 05 Aug. 2014, Water transport mechanism in the micro-porous layer (MPL) is reported from various viewpoints. Recently, the wettability of the MPL is attracted as a key to improve the performance of a polymer electrolyte fuel cell (PEFC). According to the earlier study investigating the influence of MPL wettability on cell performances, the cell with hydrophilic MPL showed better cell performance in a wide range of humidity conditions compared with the cell with hydrophobic MPL (1). In contrast, how MPL wettability affects water transport mechanism is not fully understood. In this study, we observed the cross-sectional distribution of liquid water inside both the hydrophobic and hydrophilic MPLs at the cathode side by using freezing method and cryo-SEM (2). From the observed results, we discuss the effect of the wettability on water transport phenomena in the vicinity of the MPL.

    A single cell with an active area of 1.8 cm2was used in the experiment. Both anode and cathode bipolar plates had straight flow channels. Hydrogen and air were used for the anode and the cathode side gases, respectively. In the experiments, the cell was set in a thermostatic chamber to keep the cell temperature constant. Two types of cathode side MPLs with different wettability were used in this study; the conventional hydrophobic MPL is composed of carbon black and PTFE, and the hydrophilic MPL is composed of carbon fiber and ionomer. The interface between the cathode side MPL and the catalyst layer (CL) were fabricated by the gas diffusion electrode (GDE) method (1). The GDE method improves interfacial contact between the MPL and the CL by directly coating the catalyst ink on the MPL. These membrane electrode assemblies (MEAs) were experimentally produced by Asahi Glass Co., Ltd.

    In this study, the experiment consisted of cell performance measurement and the observation of liquid water in the vicinity of MPLs. The freezing method and cryo-SEM were used for the observation (2). The method immobilizes the liquid water in the cell immediately after discontinuing operation by freezing them, and the cryo-SEM observation can visualize the liquid water distribution in the vicinity of the MPL at high spatial resolution without ice melting.

    Figure 1 is the cryo-SEM images of the cathode side MEA before operation. Figures 1(a) and 1(b) are the images of the hydrophobic and hydrophilic MPLs respectively. The structure of the hydrophilic MPL with the carbon fibers is clearly different form the conventional hydrophobic MPL with carbon blacks. The pore size of the hydrophilic MPL is larger than that of the hydrophobic MPL. Figures 1(c) and 1(d) are images of the hydrophobic and hydrophilic MPL/CL interfaces, respectively. The interface between the hydrophobic MPL and the CL can be hardly distinguished because both the hydrophobic MPL and the CL are composed of carbon black. In contrast, the interface between the hydrophilic MPL and the CL can be clearly observed due to the hydrophilic MPL with carbon fiber.

    Figure 2 is the cryo-SEM images of the cathode side MEA after the operation. Figures 2(a) and (b) are the hydrophobic and hydrophilic MPLs respectively. The cell was operated at 70 ºC, and constant current density was 0.7A/cm2. Relative humidity was set at 81% (MEA with hydrophobic MPL) and 100% (MEA with hydrophilic MPL). The ice distributions in the hydrophobic and hydrophilic MPLs are clearly different. There is no ice in the hydrophobic MPL (Fig. 2(a)). In contrast, much ice is observed in the hydrophilic MPL (Fig. 2(b)). The difference in the ice distributions is due to the wettability of the MPL. Figures 2(c) and (d) are the hydrophobic and hydrophilic MPL/CL interfaces, respectively. Although the further investigation is required under other conditions, e.g. dry condition, ice in the CL of the MEA having the hydrophilic MPL appears to be little as compared with ice in the CL of the MEA having the hydrophobic MPL. There might be a possibility that the hydrophilic MPL drains liquid water from the CL.

    References T. Tanuma and S. Kinoshita, J. Electrochem. Soc., 161, F94 (2014).

    Y. Aoyama, K. Suzuki, Y. Tabe, and T. Chikahisa, Electrochem. Commun., 41, 72 (2014).
  • Analysis of Effects by Introducing Distributes Cooperative CGS in North City
    赤澤 眞之; 鈴木 研悟; 田部 豊
    エネルギー・資源学会研究発表会講演論文集, 10 Jun. 2014, エネルギー・資源学会, Japanese
    10 Jun. 2014 - 10 Jun. 2014
  • 固体高分子形燃料電池におけるMPLの界面構造と濡れ性が水輸送現象に及ぼす影響
    青山祐介; 鈴木研悟; 田部豊; 近久武美; 田沼敏弘
    日本伝熱シンポジウム講演論文集(CD-ROM), 2014
    2014 - 2014
  • ANALYSIS OF LIQUID WATER BEHAVIOR IN GAS DIFFUSION LAYERS OF PEFC USING LATTICE BOLTZMANN METHOD
    Y. Tabe; T. Azuma; Y. Honjo; K. Suzuki; T. Chikahisa
    Proceedings of the 25th International Symposium on Transport Phenomena, 2014, English
    2014 - 2014
  • Structural optimization of porous flow fields to improve water management ability of PEFC
    K. Suzuki; D. Sato; Y. Tabe; T. Chikahisa
    Proceedings of the 15th International Heat Transfer Conference, 2014, English
    2014 - 2014
  • C212 Degradation Characteristics of Polymer Electrolyte Membrane Fuel Cell Resulting from Cold Start
    ISHIMA Yuta; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of the National Symposium on Power and Energy Systems, 2014, Japanese
    In polymer electrolyte fuel cells (PEFCs), the produced ice below freezing temperature has the potential to adversely affect the structure of cathode catalyst layer (CL) and the cell performance. This study investigated degradation characteristics of a PEFC resulting from produced ice in CL. To repeat cold start in a short time, we introduce N_2 purge to remove the produced ice below freezing temperature. The cycle of cold start at -10℃ makes the cell performance gradually-degraded in high current density region. The freezing period becomes longer and the cell resistance at shutdown increases after the cold start cycle. The results suggested that produced ice degrades the contact of CL and micro porous layer.
  • C133 Model analysis of consumer selection for space heating and boiler systems in Hokkaido
    SUZUKI Kengo; OTA Jun; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of the National Symposium on Power and Energy Systems, 2014, Japanese
    The deployment of energy saving and fuel substitution is affected by the mechanism of boiling and heating systems selection by household. This study developed the Conjoint Analysis to deal with the simultaneous selection of boiling and heating apparatuses, and analyzed the mechanism of boiling and heating systems selection by household living in rented houses in Sapporo by using conditional logit model. The result shows that the households in Hokkaido place more importance on initial cost than fuel cost when choosing boiling and cooling apparatuses. As the households using gas boiler and oil heater, about 50% of them selects gas boiler when they buy their houses, but the selection of heaters is not affected by present fuel types. About the half of households select the high efficient apparatuses, such as electric heat pumps and heat recovery-type boilers, without subsidies.
  • 335 Analysis of the effective utilization of energy to the amount of renewable energy introduction in Hokkaido
    YANAGI Yusuke; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2014, Japanese
  • 321 Investigation of electrolyte flow condition for improving the performance of vanadium redox flow battery
    SHIMADA Ryo; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2014, Japanese
  • 314 Analysis of Performance Characteristics of PEFC with Porous Flow Field
    YAEHARA Motoki; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2014, Japanese
  • 313 Effect of Catalyst Layer Structure on Cold Start Characteristics in PEFC
    NISHIKAWA Hiroshi; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2014, Japanese
  • J0610103 Study on Heat Management and Optimal Flow Channel Structure in Portable PEFC with Open Cathode and Blower Fan
    TAKAGI Kousuke; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Mechanical Engineering Congress, Japan, 2014, Japanese
    As a smaller and lighter hydrogen PEFC, we adopted "Dead-end mode" and "Open-cathode" systems. Previous study showed that dry-out and anode flooding deteriorate the cell performance under drier air and higher current density conditions. In this paper, the effective methods to prevent dry-out and anode flooding were investigated experimentally using a single cell simulating the temperature distribution in a PEFC stack. It was shown that, in the condition that dry-out is caused easily by large increase in the cell temperature, the higher flow rate of the cathode air with low humidity improves cooling capacity, but also makes the MEA drier, resulting in dry-out. This means that it is difficult to suppress the dry-out by the control of the cathode air and other cooling method is needed. The results of experiment introducing a cooling channel showed that the control of the cooling air through the cooling channel is effective for suppressing the dry-out, and the control of the cathode air is also effective for suppressing the anode flooding.
  • Effect of Interfacial Structure Between Micro-Porous Layer and Catalyst Layer On Water Transport in PEFC
    Yusuke Aoyama; Kengo Suzuki; Yutaka Tabe; Takemi Chikahisa; Toshihiro Tanuma
    ECS Meeting Abstracts, 27 Oct. 2013, The Electrochemical Society
    27 Oct. 2013 - 27 Oct. 2013, Abstract not Available.
  • 凍結固定化法を用いた固体高分子形燃料電池におけるMPL内水輸送現象のCryo-SEM観察
    青山祐介; 鈴木研悟; 田部豊; 近久武美; 田沼敏弘
    日本伝熱シンポジウム講演論文集(CD-ROM), 2013
    2013 - 2013
  • NUMERICAL SIMULATION OF CONDENSED WATER BEHAVIOR IN GAS DIFFUSION LAYERS OF PEFC USING THE LATTICE BOLTZMANN METHOD
    Yutaka Tabe; Ryuji Kamijo; Yuji Honjo; Kengo Suzuki; Takemi Chikahisa
    PROCEEDINGS OF THE 11TH INTERNATIONAL CONFERENCE ON NANOCHANNELS, MICROCHANNELS, AND MINICHANNELS, 2013, 2013, AMER SOC MECHANICAL ENGINEERS, English
    2013 - 2013, Numerical simulations using the lattice Boltzmann method (LBM) has been developed to elucidate the dynamic behavior of condensed water in a gas diffusion layer (GDL) of a polymer electrolyte membrane fuel cell (PEFC). Here, a LBM model of two-phase flow with equal densities was applied, because the condensed water behavior is less affected by the gas flow. The simulation results showed that the LBM applied here can simulate dynamic capillary fingering at low migration speeds of liquid water in a GDL, which is similar to the results of the LBM simulation with large density differences. Using the equal density LBM, we conducted efficient large-scale analyses to elucidate the effect of the GDL structure and wettability on the liquid water behavior inside of the GDL.
  • ANALYSIS OF WATER TRANSPORT IN THE VICINITY OF MICRO-POROUS LAYER IN PEFC WITH FREEZING METHOD
    Yusuke Aoyama; Kengo Suzuki; Yutaka Tabe; Takemi Chikahisa
    PROCEEDINGS OF THE 11TH INTERNATIONAL CONFERENCE ON NANOCHANNELS, MICROCHANNELS, AND MINICHANNELS, 2013, 2013, AMER SOC MECHANICAL ENGINEERS, English
    2013 - 2013, This paper examines the role of micro porous layers (MPLs) in Polymer Electrode Fuel Cells (PEFCs) by observing the cross-sectional distribution of condensed water inside a cathode side MPL In addition, the forms of water condensation in the vicinity of a MPL are also compared between two places, under flow channels and under lands, by observing both inside the MPL and an interface between the MPL and a catalyst layer (CL). The freezing method and a cryo-scanning electronic microscope (cryo-SEM) are used for the observation. The result under the non-flooded condition shows that condensed water does not accumulate inside the MPL. This result indicates that the water produced by PEFC power generation passes through the MPL as vapor state under non-flooded conditions.
  • THE APPROPRIATE BLEND PROPORTIONAL FACTOR VALUE OF TWO STAGGERED GRIDS USED IN THE FREE ENERGY BASED LBM WITH LARGE DENSITY RATIO
    Jia-ming Gong; Nobuyuki Oshima; Yutaka Tabe
    PROCEEDINGS OF THE 11TH INTERNATIONAL CONFERENCE ON NANOCHANNELS, MICROCHANNELS, AND MINICHANNELS, 2013, 2013, AMER SOC MECHANICAL ENGINEERS, English
    2013 - 2013, The effect of blend proportional factor a used in the free energy based two-phase flow LBM model with large density ratio on the shape description of a water droplet is investigated. The blend proportional factor a which combines the two kinds of staggered grids is adopted in the calculation process of the Poisson equation based fractional step method to satisfy the mass conservation in the LBM scheme, it is found to lead to varied degrees of shape deformation of a simulated liquid water droplet. The shape deformation degree of a liquid water droplet with certain dimensionless radius is measured by the radius lengths in 8 directions. The appropriate a which gives the better shape description accuracy of a water droplet with certain dimensionless radius is explored and its value change tendency with the dimensionless radius lengths is summarized The a's effect on the shape deformation is also presented
  • A214 Optimizing geographical distribution of wind power plants in Hokkaido to decrease power fluctuation risk
    SUZUKI Kengo; NAKANISHI Takahiro; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of the National Symposium on Power and Energy Systems, 2013, Japanese
    To spread the wind power technology, the power fluctuation risk of wind power plants, i.e.a risk of frequent and large reduction in the output caused by time-varying wind speeds, need to be decreased. Among measures against the risk, the geographical distribution of wind power plants needs to be examined first because additional facilities, such as backup thermal power plants or electricity storages, are not required. This study analyzes the risk reduction effect of geographically distributing wind power plants among the regions within Hokkaido. The mean-CVaR (Conditional Value at Risk) model is adopted to estimate optimum geographical distribution of the plants. We found that the geographical distribution can largely decrease the power fluctuation risk. Such a result indicates that the Hokkaido has enough variety of climates to largely decrease the power fluctuation risk of wind power plants by domestic geographical distribution.
  • A213 Estimating job-creation effect derived from introduction of wind power plants by applying input-output table of Hokkaido
    AOKI Toshinori; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of the National Symposium on Power and Energy Systems, 2013, Japanese
    When introducing renewable energies, the job-creation effect needs to be considered in addition to stable supply of energy and countermeasures against global warming. In this paper, we estimated the job-creation effect in the life cycle of wind power plants which is expected to be massively introduced into the Hokkaido, the life cycle of wind power generation includes manufacture of a wind turbine, power generation, operation and maintenance. Input-output table analysis is applied for the estimation, and wind power generation sector is newly added to the published version of the Hokkaido input-output table. The life cycle job-creation is estimated to be 1.34 person*year/GWh Of these, 0.57 person*year/GWh are Construction of wind turbine and 0.77 person*year/GWh are wind power generation About 30% of the life cycle job-creation is created outside the Hokkaido.
  • A103 Analysis of Oxygen Transport Resistance in PEFC Cathode Catalyst Layer for Mechanism in Shutdown Process
    YAMADA Kazuki; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of the National Symposium on Power and Energy Systems, 2013, Japanese
    In polymer electrolyte fuel cells (PEFCs), the freezing of produced water makes cell performance worse below zero In this study, we investigated the freezing phenomena in the cathode catalyst layer (CL) by the experiments, and identified the effects of current density, cathode gas pressure, and oxygen concentration It was shown from the results that the ice distribution in the CL and the estimated amount of ice produced in the CL till the shutdown depend on the current density while they are independent of the cathode gas pressure and the oxygen molar concentration To clarify the main cause dominating these tendencies in the cold start, we introduced the effect of ice formation on an increase in the through-plane electrical resistance of the CL into the three phase boundary and the CL models, and examined the freezing mechanism in the CL
  • 510 Mitigation and cost analysis of fluctuating electricity generation caused by large share of wind power plants in Hokkaido
    TENJIMBAYASHI Daishi; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2013, Japanese
  • 509 Nonlinear Model Analysis of CO2 and Cost in Distributed and Cooperative CHP System
    AKAZAWA Masayuki; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2013, Japanese
  • 502 Analyzing Key Influencing Factors for Diesel NOx Reduction by Enhanced Mixing of Combustion
    TAGUMA Yuichi; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2013, Japanese
  • 501 Study on Cooling Loss Model for High Speed Engine Simulation
    MATSUKAWA Daisuke; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2013, Japanese
  • 410 Degradation characteristic of polymer electrolyte membrane fuel cell at cold start
    ISHIMA Yuta; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2013, Japanese
  • 407 Study on Optimal Structure and Cooling System in Portable PEFC
    TAKAGI Kousuke; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2013, Japanese
  • 406 Analysis of Cathode Catalyst Layer Structure and Cell Performance in PEFC
    AKABORI Sho; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2013, Japanese
  • I142 LBM Analysis of the Effect of Wettability Distribution on Liquid Water Transport in GDL of PEM FC
    Honjo Yuji; Suzuki Kengo; Tabe Yutaka; Chikahisa Takemi
    The Proceedings of the Thermal Engineering Conference, 2013, Japanese
    Flooding is one of the problems to be solved for practical use of PEFC. In this study, the numerical simulation using the lattice Boltzmann method (LBM) was developed to elucidate the liquid water behavior in a gas diffusion layer. In the equal density LBM code developed by the authors, there is a problem that setting value of water flow rate was not ensured. This paper explains the applied improvements for setting the inlet boundary conditions, keeping the fast calculation for the large-scale simulation, and the improved results. The instability of simulation, however, still remains as an unsolved issue, and the cause is also discussed.
  • I123 Analysis of the Effect of Current Density Distribution on Cell Performance in Redox Flow Battery
    Kadowaki Tsubasa; Suzuki Kengo; Tabe Yutaka; Chikahisa Takemi
    The Proceedings of the Thermal Engineering Conference, 2013, Japanese
    The vanadium redox flow battery (VRB) has emerged as a viable grid-scale energy storage technology that offers energy storage solutions for renewable energy applications. In this study, we focus on the effect of material transport and electrolyte concentration distribution on cell performance. The original cell was specially designed for measurement of current density distribution, and the analysis method was established. In the method, the measured values just after the start of discharge were used to identify the non-uniform contact resistances, and the current density distribution unaffected by the measurement devices can be estimated. The measurement results showed that the current density decreases along the electrolyte flow, and the range of the current density and the cell performance are improved by increasing the electrolyte flow rate.
  • J061051 Study on Electrode Structure and Electrolyte Flow for Performance Improvement in Redox Flow Battery
    SUGIMOTO Ryo; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Mechanical Engineering Congress, Japan, 2013, Japanese
    The use of the redox flow battery as a large-capacity rechargeable battery is one of the solutions for equalization of the outputs of wind power and photovoltaic power. In this study, we focus on electrode structure and the electrolyte flow of the redox flow battery, because those optimum design is necessary for improving total system performance. We tested with three kinds of electrode structure, and confirmed the influence of the electrolyte flow rate. At low SOC (state of charge), the discharge performance is greatly affected by the concentration overpotential at low flow rate of the electrolyte. In the case of the electrode structure with electrolyte flow channel, the effect of the concentration overpotential becomes larger in comparison with the electrode structure without electrolyte flow channel, indicating that most electrolyte flows in the flow channel and diffusion of the reactant is dominant for the cell performance. With the electrode without the channel (3mm or 6mm thick carbon felt), the effect of electrode thickness is small up to current density around 40mA/cm^2 even at low electrolyte flow rate, while thicker electrode improves the cell performance at high current density because of the larger effective reaction area of the carbon felt.
  • J061043 Influence of material and structure of PEFC porous channel on thermal and water management
    SATO Daiki; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Mechanical Engineering Congress, Japan, 2013, Japanese
    According to earlier studies, the porous flow channel of Polymer Electrode Fuel Cell (PEFC) are more tolerant against flooding phenomenon, but less tolerant against dry-out phenomenon in comparison with conventional flow channels such as straight and serpentine type channels. However, the relationship between the porous structure and water management ability of porous media has not been clarified. This study investigated the influence of porosity and pore structure of porous bipolar plates on the tolerance of single cell against flooding and dry-out phenomena. The porous media produced by sintering Titanium fibers are used as the flow channels. The results show that the porous flow channel with lower porosity is more tolerant against dry-out phenomenon and less tolerant against flooding phenomenon. The best porosity of the flow channel seems to be in the range between 85-93%. The results also indicate that the porous media made of metal fibers with larger diameter has less water management ability because the special variety of porous and metal becomes larger.
  • Numerical simulation of the effect of enhanced combustion zone mixing on NOx reduction by decreasing residence-time-scales in high temperature zones in diesel engines
    Masaru Kubo; Yutaka Tabe; Takemi Chikahisa
    Proceedings of the 8th International Conference on Modeling and Diagnostics for Advanced Engine Systems, COMODIA 2012, 01 Dec. 2012
    01 Dec. 2012 - 01 Dec. 2012, Diesel engines have high thermal efficiency, but suffer from the problem of relatively high emissions of NOx and particulate matter. The authors have shown that NOx is mostly generated at the flame tip region where mixing strength decrease significantly and maintains high temperatures for longer times than other regions. Based on this assumption, the authors proposed a combustion concept to reduce NOx by introducing high turbulence in the combustion chamber during the combustion period. The present paper reports simulations of the turbulence intensity and NOx reduction for an engine, which is designed to generate a strong jet from a special cell. The cell, which is termed CCD in the paper, is added to a direct injection diesel engine, and a small amount of fuel is injected into the cell to create the strong jet entering the main chamber. The numerical simulations showed that NOx increased significantly by the jet from the cell, the opposite of the expected result. However it was shown that a significant NOx reduction was obtained when the jet was injected in the same direction as the fuel injection, showing the viability of the concept. Copyright © 2012 by the Japan Society of Mechanical Engineers.
  • J056024 Mass Conversation Improvement in LBM and Its Application in PEFC Simulation
    Gong Jiaming; Oshima Nobuyuki; Tabe Yutaka; Yasser Ben Salah
    Mechanical Engineering Congress, Japan, 09 Sep. 2012, The Japan Society of Mechanical Engineers, English
    09 Sep. 2012 - 09 Sep. 2012, The emergence and transportation process of liquid water from a micro-pore on the gas diffusion layer surface under the action of gas flow in a polymer electrolyte membrane fuel cell (PEFC) is simulated by a modified free energy based lattice Boltzmann method (LBM) with large density ratio. A so called space averaged index function method is used to improve the mass conservation in the LBM scheme. And the effect of the GDL surface wettability on the liquid water removal efficiency is investigated. The simulation results show that the mass conservation of the LBM for the 3D simulation has been greatly improved and satisfied. The highly hydrophobic surface of GDL has a better performance in liquid water removal and less surface coverage area. It is shown that this LBM method can be an effective tool in simulating the two phase flow in the PEFC.
  • Scenario Analysis of Reduction and Leveling of the Electricity Demand in Residential Sector Considered Our Power Demand Characteristics
    青山 祐介; 鈴木 研悟; 田部 豊
    エネルギー・資源学会研究発表会講演論文集, 05 Jun. 2012, エネルギー・資源学会, Japanese
    05 Jun. 2012 - 05 Jun. 2012
  • Observation of Water Transfer Phenomena in Micro-Porous Layer of PEFC
    Yusuke AOYAMA; Kazumasa Kadowaki; Yutaka Tabe; Takemi Chikahisa
    ECS Meeting Abstracts, 04 Jun. 2012, The Electrochemical Society
    04 Jun. 2012 - 04 Jun. 2012, Abstract not Available.
  • STUDY ON WATER TRANSPORT PHENOMENA THROUGH MICRO-POROUS LAYERS IN PEFC
    Takemi Chikahisa; Yutaka Tabe; Kazumasa Kadowaki
    PROCEEDINGS OF THE ASME 10TH INTERNATIONAL CONFERENCE ON NANOCHANNELS, MICROCHANNELS AND MINICHANNELS 2012, 2012, AMER SOC MECHANICAL ENGINEERS, English
    2012 - 2012, Micro-porous layers (MPLs) play an important role in the water management of polymer electrolyte fuel cells (PEFCs), but details of the mechanism that works to suppress water flooding has not been fully understood. In this study, the authors investigated water distribution at the interface between the MPL and the catalyst layer (CL) at the cathode side to clarify the effect of the MPL on the discharge of produced water. A freezing method was applied to observe the distribution of the condensed water, and the ice distribution on the CL surface was quantified by image processing. The effects of operating conditions on the water distribution were examined at normal temperature conditions. The distribution of ice formed on the surface of the CL with and without MPL after -10 degrees C cold start operation was also established. Water transport rate in the vapor phase was analyzed based on temperature and vapor pressure gradient considerations. The experiments and the analysis showed that the MPL functions to prevent accumulation of water on the surface of the CL, resulting in less water flooding.
  • DECISION OF THE BEST BLEND PROPORTIONAL FACTOR VALUE OF TWO STAGGERED GRIDS USED IN LBM FOR PEFC SIMULATION
    Jia-ming Gong; Nobuyuki Oshima; Eru Kurihara; Yutaka Tabe
    PROCEEDINGS IF THE ASME 9TH INTERNATIONAL CONFERENCE ON NANOCHANNELS, MICROCHANNELS AND MINICHANNELS 2011, VOL 1, 2012, AMER SOC MECHANICAL ENGINEERS, English
    2012 - 2012, The appropriate blend proportional factor value which combines two kinds of staggered grids used in Lattice Boltzmann Method (LBM) for simulating the multiphase flow phenomena with large density ratio in the Polymer electrolyte fuel cell (PEFC) is fixed on. The shape deformation of the water droplet is found when using the two kinds of staggered grids to prevent the pressure oscillation when solving the Poisson equation of this LBM model and the shape of the water droplet varies with the changes of the blend proportional factor values. Two methods are adopted to find out the two staggered grids' appropriate blend proportional factor value that can diminish or minimize the deformation of the droplet. The first one is to compare the simulation results of different blend proportional factors with the theoretical value and find the one mostly approaches the theoretical value; the second one is to compare the current velocity divergences of the two staggered grids using the results calculated by different blend proportional factor values. A water droplet resting in a tunnel is simulated with different blend proportional factor values and the appropriate value is decided.
  • J056026 Numerical Simulation of Gas-Liquid Two-Phase Flow in a Gas Diffusion Layer of PEFC Using the Lattice Boltzmann Method
    KAMIJO Ryuji; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Mechanical Engineering Congress, Japan, 2012, Japanese
    For practical use of a polymer electrolyte fuel cell (PEFC), a flooding phenomenon is one of the problems to be solved. The flooding is caused by liquid water accumulated in the gas diffusion layer (GDL) and the gas flow channels and deteriorates the performance of the PEFC. Therefore, it is necessary to clarify the gas and liquid flow in the PEFC and to control the liquid water behavior appropriately. Our research group applied the lattice Boltzmann method (LBM) for the two phase flow with high density ratio, considering the effect of wettability, and has carried out the analyses of gas and liquid water to propose optimal structures of the PEFC. Here, the LBM is a method to reproduce the macroscopic flow by considering fluid as an aggregate of a virtual particle and calculating those collisions and translation sequentially, and suitable for the two-phase flow simulation with complex boundary geometries. In this study, we simulated liquid water behavior inside of the GDL applying a low density ratio LBM with shorter computational time instead of the high density ratio model. It was confirmed that the effect of large density difference on the liquid water behavior is negligible because of the weak gas flow inside of the GDL. Using the LBM with low density ratio, we tried efficient large-scale analyses in the GDL to elucidate the effect of the GDL structure and wettability on the liquid water behavior inside of the GDL.
  • J056025 Analysis and Experiments of Major Parameters in Catalyst Layer Structure Affecting on PEFC Performance
    KOBAYASHI Masaya; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Mechanical Engineering Congress, Japan, 2012, Japanese
    Because electron, proton, and oxygen are necessary for the cathode reaction in polymer electrolyte fuel cell, achieving the optimum structure of electrode catalyst layer and the efficient transport of the reactants is significantly effective to reduce the usage of Pt catalyst in polymer electrolyte membrane fuel cells (PEFCs). In this paper, we estimated the major parameters such as the radius of the carbon agglomerate with polymer electrolyte and the thickness of the catalyst layer from structural observation of the fabricated CCM by a Scanning Electron Microscope (SEM). The polarization characteristics of the cell performance were calculated using an agglomerate model with the experimentally estimated parameters, and the simulation model was validated by comparing the simulated and experimental results. Then, we evaluated the effects of the major parameters such as the polymer electrolyte film thickness covering carbon agglomerates on the cell performance by the simulation, and present a new concept effective for reducing the identified major resistances such as the oxygen diffusion resistance in the polymer by controlling the film structure of polymer electrolyte.
  • D203 Analysis of Liquid-Water Behavior and Cell Performance in PEFC with Porous Separator
    HONJO Yuji; CHIKAHISA Takemi; TABE Yutaka
    The Proceedings of the National Symposium on Power and Energy Systems, 2012, Japanese
    For improvement on performance of a polymer electrolyte fuel cell (PEFC), it is necessary to ensure appropriate management of reaction gas, generated water and temperature in the cell. In this study, we investigated possibilities of a structure without GDL and an internal cooling method in a PEFC with porous cathode separator experimentally. The results showed that the performance of a single cell without GDL decreases due to uneven contact and high contact resistance between the porous separator and the catalyst layer. It is considered that applying a micro porous layer to the interface of the porous cathode separator is effective for the improvement. It was also shown that the internal cooling method using evaporative latent heat has effects of not only cooling cell but also maintaining high humidity inside the cell even if humidity of supply gas is low.
  • D201 Effect of Air Flow Conditions on Water Transport in Air-Breathing PEMFC with Dead-End Hydrogen Flow
    ITOMI Muneji; SATOH Daiwa; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of the National Symposium on Power and Energy Systems, 2012, Japanese
    As a smaller and lighter hydrogen PEFC, we adopted "Dead-end mode" and "Air-breathing" systems and tried to improve the cell performance with a small fan. In this paper, the effects of cathode air flow rate and cell temperature on the cell performance were investigated experimentally. It was shown that under low relative humidity conditions higher flow rate makes the CCM drier and causes dryout, but suppresses the increase in the cell temperature by the reaction heat. The increase in the cell temperature also induces dryout, so appropriate temperature management as well as water management by the small fan is important for stable high cell performance of this PEFC system.
  • C124 Analysis of water transport phenomena in MEA in PEM electrolysis cell
    KASHIWASE Koji; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of the National Symposium on Power and Energy Systems, 2012, Japanese
    This paper shows an analysis of water transport phenomena in MEA in PEM electrolysis cell. In previous study, it was shown that the change of water transport pattern in diffusion layer and catalyst layer doesn't affect performance and Nafion membrane may be directly related to performance. In this study, a numerical analysis to clarify the water transport phenomena in MEA based on the experimental data (the amount of discharged water from the cathode and the impedance) was developed. The result showed that the effect of osmotic force on the water transport through the MEA is far larger than that of diffusion force and water content in Nafion membrane may increase as current density increases.
  • 414 Diffusion Analysis of Future Type Residential Energy Devices Based on Consumer Preference Model
    OTA Jun; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2012, Japanese
  • 413 Estimating increase of employment derived from introducing wind power plants by applying extended input-output table of Hokkaido
    AOKI Toshinori; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2012, Japanese
  • 412 Design of Gas Flow Channels for Preventing Dry-Out and Flooding in Air-Breathing PEFC
    HONJO Yuji; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2012, Japanese
  • 411 Analysis of Oxygen Transport Resistance in PEFC Cathode Catalyst Layer at Cold Start
    YAMADA Kazuki; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2012, Japanese
  • 410 Researching PEFC with High Periormance and Simple Structure by Introducing the Porous Bipolar Plates
    SATO Daiki; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2012, Japanese
  • 408 Basic Study on Improvement of Charge-Discharge Efficiency in Redox Flow Battery
    SUGIMOTO Ryo; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2012, Japanese
  • 407 Basic Study on Transfer Phenomena in Large-Capacity Storage Battery
    KADOWAKI Tsubasa; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2012, Japanese
  • 204 Study on Diesel Combustion Model for Total Engine Simulator
    MISHIMA Shumpei; SUZUKI Kengo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2012, Japanese
  • STUDY ON SIMPLE AND HIGH-SPEED DIESEL COMBUSTION MODEL FOR DRIVING MODE SIMULATOR AVAILABLE FOR PREMIXED AND DIFFUSION COMBUSTION OF SPRAYS
    Takemi Chikahisa; Yutaka Tabe; Kazushige Kikuta; A. S. M. Sayem
    PROCEEDINGS OF THE ASME/JSME 8TH THERMAL ENGINEERING JOINT CONFERENCE 2011, VOL 2, 2011, AMER SOC MECHANICAL ENGINEERS, English
    2011 - 2011, To design a diesel engine adapting to future exhaust gas regulation, it is important to develop a driving mode simulator which can simulate vehicle performance and exhaust emissions including after-treatment system. The combustion model for this objective must be able to simulate heat release rate, variety of emissions necessary for after-treatment simulation, and exhaust gas temperature in very short computational time. The authors have developed a diesel combustion model based on the Hiroyasu model by adding variety of modifications to minimize optimization process of the empirical constants. It was shown that the simulation results with the improvement model were in good agreement with the experimental results. By adding Tsurushima model consisting of nine reaction steps with several intermediate species, the model became available for the both combustions of spray diffusion flame and of homogeneous charge compression ignition..
  • MICROSCOPIC OBSERVATION OF ICE DISTRIBUTION IN PEM FUEL CELL AT COLD START
    Yutaka Tabe; Masataka Saito; Ryosuke Ichikawa; Takemi Chikahisa
    PROCEEDINGS OF THE ASME/JSME 8TH THERMAL ENGINEERING JOINT CONFERENCE 2011, VOL 2, 2011, AMER SOC MECHANICAL ENGINEERS, English
    2011 - 2011, In Polymer electrolyte membrane fuel cells (PEFCs), freezing of produced water induces the extreme deterioration of cell performance below zero. This phenomenon is a serious problem in cold regions and is needed to be solved to achieve the practical use of PEFCs. In this study, we investigated ice distribution at the cold start in a PEFC using an optical microscope and a CRYO-SEM to clarify the freezing mechanism. The observation results showed that the cold start at -10 degrees C makes ice at the interface between the cathode catalyst layer (CL) and the micro porous layer of gas diffusion layer Little ice was, however, observed in the cold start at -20 degrees C, which indicated the ice formation inside the CL. The CRYO-SEM observation was conducted at -20 degrees C to investigate the ice formation inside the CL, and this identified the effects of the current density and the cathode gas species on the ice distribution.
  • Study on simple and high-speed diesel combustion model with wall impingement
    Satoshi Sakaida; Yutaka Tabe; Takemi Chikahisa
    SAE Technical Papers, 2011, English
    2011 - 2011, To design diesel engines adapted to future exhaust gas regulation, it would be advantageous to have a driving mode simulation for vehicle performance and exhaust emissions, including after-treatment systems. The combustion model for this objective must be able to simulate the engine performance in very short time. We have tried to develop such diesel engine combustion model by adding the improvements to the Hiroyasu model. In this paper, we detail the improvements that were added to this model and comparisons the calculated results by the improved model with experimental result. © Copyright 2011 Society of Automotive Engineers of Japan, Inc. and SAE International.
  • 611 Analysis on Long-term Change of Energy System Structure in Japan for CO_2 Emission Reduction and Increase of Domestic Industry Investment
    Nakanishi Takahiro; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2011, Japanese
  • 610 Numerical simulation of liquid water behavior in PEFC using Lattice Boltzmann Method
    KAMIJO Ryuji; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2011, Japanese
  • 609 Propagation Scenario Analysis of Low Environmental Burden Devices Based on Consumer's Preference Selection Model
    AOYAMA Yusuke; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2011, Japanese
  • 608 Analysis and Experiment of Major Parameters in Catalyst Layer Structure Affecting on PEFC Performance
    KOBAYASHI Masaya; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2011, Japanese
  • 606 Effect of NOx Reduction by Mixing JET in Diesel Engine
    Kubo Masaru; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2011, Japanese
  • G201 Effect of Micro Porous Layer on Water Distribution in PEFC
    Kadowaki KAZUMASA; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of the National Symposium on Power and Energy Systems, 2011, Japanese
    Micro Porous Layer (MPL) play an important role in the water management of PEFC, but details of the mechanism to suppress water flooding has not been fully understood. In this study, we investigated condensed water distribution at the interface between MPL and MEA to clarify the effect of MPL on discharge of produced water. Freezing method was applied to observe the distribution of the condensed water, and the distribution on the MEA surface was quantified by a binary image processing. The results indicated less amount of condensed water distribution on the MEA surface in the case of GDL with MPL than in the case of GDL without MPL. Next, comparing normal operation with start-up temperature -10℃, there is large amount of condensed water on the MEA surface after operation at -10℃. Based on these results, the MPL has a role to prevent accumulated water on the surface of MEA, and suppresses water flooding. In operation at -10℃, generated water which becomes supercooled water freezes at the interface between MEA and MPL, and large ice agglomerates are generated on the surface of MEA.
  • H101 Analysis on Long-term Change of Energy System Structure in Japan for CO_2 Emission Reduction and Economic Revitalization
    TABE Yutaka; KUROKAWA Shingo; CHIKAHISA Takemi
    The Proceedings of the National Symposium on Power and Energy Systems, 2011, Japanese
    Long-term change of energy system structure in Japan was analyzed to investigate the effect of CO_2 emission reduction level using MARKAL model. The MARKAL is composed of energy resources, energy supply technologies, energy ultimate demand technologies and energy service demands with them connected by energy carriers. This paper presents analyses investigating the CO_2 reduction cost and the energy structure change until 2050. Here, we focused on the domestic investment to reduce CO_2 emission. It was shown that the CO_2 reduction until 40% level promotes the energy conversion from coal to natural gas and it causes the increase in total cost of the imported fuel. The higher CO_2 reduction, however, increases the domestic investment for low-emission vehicles, photovoltaic power generation and so on, and decreases the outward investment, although the total CO_2 reduction cost is increased. This contributes to the revitalization of Japanese economy, together with the reduction of outward investment.
  • G115 Effect of Freezing Phenomena in Cold Start of PEFC on Normal Operation
    ICHIKAWA Ryosuke; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of the National Symposium on Power and Energy Systems, 2011, Japanese
    In PEM fuel cell below zero, freezing under the cold start sometimes causes a deterioration of cell performance in normal operation. In particular, this phenomenon is especially prominent after the -10℃ start than after the -20℃ that. This is because the ice formed at the interface between the cathode catalyst layer and GDL at the -10℃ start. This paper focused on the effect of current density and tightening pressure of the cell, and investigated the mechanism of the -10℃ start effect on normal operation. The results showed that the performance deterioration is large as current density at the -10℃ start is small. This phenomenon became prominent in case of small tightening pressure of the cell because of wide ice formation on the catalyst layer surface.
  • G114 Effect of Condensed Water at Anode and Cathode Sides in Air-breathing PEFC with Dead-end Hydrogen Flow
    SATOH Daiwa; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of the National Symposium on Power and Energy Systems, 2011, Japanese
    The methods for smaller and lighter PEFC systems include "Dead-end mode" and "Air-breathing". However, it is difficult to discharge water, and PEFC systems using these methods have agenda that they make it easier to flood. In this paper, we investigated the effect of condensed water on the cell performance experimentally. Shorter operation time and more condensed water were observed at higher relative humidity (RH) and higher current density (0.3A/cm^2) condition than at lower RH and lower current density (0.2A/cm^2). At lower RH and lower current density, it was confirmed that the causes of shutdown are flooding by the condensed water on the channel bottoms at the cathode side and the water on the GDL surface at the anode side. We were able to prevent the cathode flooding by continuous removal of the accumulated water and the anode flooding by less-frequent hydrogen purge.
  • D215 Effect of melt flow and temperature distribution on GaAs growth
    KIMURA Yoshitaka; TABE Yutaka; CHIKAHISA Takemi; FUTAKUCHI Naoki
    The Proceedings of the Thermal Engineering Conference, 2011, Japanese
    2D computer simulation assists in the decision of growth parameters to reduce the crystal defects of GaAs crystal in liquid encapsulated Czochralski (LEC) method. In this paper, we numerically investigated the reason why the 450mm-long crystal has more crystal defects than the 350mm-long crystal by comparing heat exchange, temperature distribution and velocity vector in the source melt at several stage of the growth. The simulation results indicated that large heat release from crystal and small heat release from crucible bottom are advantageous to the crystal growth with few defects. It is also necessary that forced convection and natural convection of GaAs melt is delicately controlled by the crucible rotation rate and the temperature distribution.
  • LIQUID WATER AND GAS FLOW SIMULATION IN A CHANNEL OF PEM FUEL CELS USING THE LATTICE BOLTZMANN METHOD
    Ben Salah Yasser; Yutaka Tabe; Takemi Chikahisa
    PROCEEDINGS OF THE ASME 8TH INTERNATIONAL CONFERENCE ON FUEL CELL SCIENCE, ENGINEERING, AND TECHNOLOGY 2010, VOL 1, 2010, AMER SOC MECHANICAL ENGINEERS, English
    2010 - 2010, In a polymer electrolyte membrane (PEM) fuel cell, the condensed water in the gas channel prevents the supply of reactants to electrodes, which deteriorates the cell performance. The Lattice Boltzmann simulation has been conducted to understand the behavior of condensed water in the gas channels. The scheme of the two-phase flow with large density difference was applied to find the optimum gas channel design. The present simulation demonstrates the effect of the cross-sectional shape, the droplet initial position, droplet volume and the air flow velocity for a hydrophobic gas channel. Introducing a new dimensionless parameter, which is the pump work needed to remove the droplet from the gas channel, we investigate the effect of each parameter on the drain performance of a PEM fuel cell's gas channel.
  • PERFORMANCE AND LIQUID WATER DISTRIBUTION IN PEFCs WITH DIFFERENT ANISOTROPIC FIBER DIRECTIONS OF THE GDL
    Kyaw Swar Soe Naing; Yutaka Tabe; Takemi Chikahisa
    PROCEEDINGS OF THE ASME INTERNATIONAL HEAT TRANSFER CONFERENCE - 2010, VOL 5, 2010, AMER SOC MECHANICAL ENGINEERS, English
    2010 - 2010, To maintain proton exchange membrane fuel cells (PEFC) at high efficiencies without flooding, it is necessary to control the liquid water transport in the gas diffusion layer (GDL). This experimental study investigates the effects of the GDL fiber direction on the cell performance using an anisotropic GDL. The results of the experiments showed that the efficiency of the cell was much better when the fiber direction was perpendicular to the channel direction, and that the cell with perpendicular fibers was more tolerant to flooding than the cell with fibers parallel to the channel. To determine the mechanism that gives rise to the fiber direction effects, the liquid water behavior in the channel was observed through a glass window on the cathode side. Additionally, a small cell with a 2 cm(2) active area was made, to investigate the water distribution inside the GDL by freezing the water and observing the ice distribution. These ice pictures showed that reactions are more active under channels than under ribs. This is because the accumulated water prevents reaction under the ribs, and indicates the importance of water removal from the rib zones.
  • 416 Study on Simple and High-Speed Diesel Combustion Model for Small Size Diesel Engines
    SAKAIDA Satoshi; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2010, Japanese
  • 415 Experimental Study on the Influence of Turbulence on NOx Formation in Diesel Engines
    ZHU Qianjin; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2010, Japanese
  • 414 Study on freezing phenomena in PEFC below freezing
    Ichikawa Ryosuke; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2010, Japanese
  • 413 Water Activity Characteristics in Electrolyte Membrane of Air-Breathing PEM Fuel Cell and its Water Management
    SATOH Daiwa; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2010, Japanese
  • 307 Analysis of Performance and Internal Mechanism in PEFC with Porous Separator
    NASU Takuya; MORIOKA Satoshi; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2010, Japanese
  • 113 The development of MRKAL model Database for optimized energy system analysis in Hokkaido
    NAMBA Ryouji; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2010, Japanese
  • 112 Effect of Melt Flow and Temperature Distribution on GaAs Crystal Growth
    KIMURA Yoshitaka; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2010, Japanese
  • 111 Mass Transfer Phenomena in the Vicinity of MPL
    KADOWAKI Kazumasa; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2010, Japanese
  • D204 Cold Start Effect on Cell Paformance in PEM Fuel Cell and Observation of the Freezing Phenomena
    NAMBA Ryouji; SAITO Masataka; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of the National Symposium on Power and Energy Systems, 2010, Japanese
    In PEM Fuel Cell below zero, freezing under cold start sometimes causes a temporal deterioration of cell performance in normal temperature operation. This paper investigates the mechanisms of the cold start effect on operation at normal temperature and the ice fomation in catalyst layer. The observation was performed after the cell at the freezing temperature. The results showed that the performance deterioration is caused by the ice formed at the interface between the catalyst layer and GDL, and the control of the ice amount is important to prevent depression. Cryo-SEM observation showed that there is ice in the catalyst layer, which causes the shut down, and the distribution of formed ice is affected by the operation condition.
  • D203 Analysis of Performance and Internal Mechanism in PEFC with Porous Separator
    NASU Takuya; MORIOKA Satoshi; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of the National Symposium on Power and Energy Systems, 2010, Japanese
    This study conducted perfomance evaluation of single cell with porous cathode separataor. The direct observation of the porous separator cross-section and the impedance spectra were applied. The observation showed that the porous separator is superior in the drainage performance from the GDL surface, and the hydrophily of separator fiber is important for the performance. The results of impedance spectra indicated that the porous separator is superior to the serpentine separator in the supply of reactant gas.
  • 307 Numerical simulation of PEFC with porous separator
    SHIMODATE Takuya; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of The Computational Mechanics Conference, 2010, Japanese
  • 306 Numerical Simulation of Two-phase Flow in Gas Diffusion Layer in PEFC using Lattice Boltzmann Method
    Sasaki Takayuki; Tabe Yutaka; Chikahisa Takemi
    The Proceedings of The Computational Mechanics Conference, 2010, Japanese
  • J0802-1-5 Research on hydrogen generation efficiency improvement by PEM electrolysis cell using porous body
    KASHIWASE Koji; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Mechanical Engineering Congress, Japan, 2010, Japanese
    This paper shows the experimental result of hydrogen generation efficiency by PEM electrolysis. The straight channel and titanium porous body were compared in performance. The following possibilities were shown by the experimental result: (1) The efficiency rises with increasing of temperature. (2) The porous body gave higher performance than the straight channel. (3) Cell performance deteriorated in repeating operation at relatively low current density, partially due to dry out.
  • J0802-1-1 EXPERIMENTAL AND NUMERICAL INVESTIGATION OF GAS FLOW IN POLYMER ELECTROLYTE FUEL CELL
    LITAN Litan Kumar; OSHIMA Nobuyuki; TABE Yutaka; KURIHARA Eru
    The Proceedings of Mechanical Engineering Congress, Japan, 2010, English
    In this study, the deformation effect of gas diffusion layer (GDL) on the pressure drop of polymer electrolyte fuel cell (PEFC) separator channel has been investigated both numerically and experimentally. Gas channel and gas diffusion layers are regarded as two important parts of PEFC because they transport reactant gases to the catalyst layer and also byproduct from the catalyst layer. The deformation of GDL caused by the compression pressure plays an important role in the performance of PEFC since it affects the physical properties of the GDL, such as porosity, permeability and the cross sectional area of the gas channel. The flow behavior in the separator channel and GDL of PEFC has been investigated by using a transient, isothermal and three-dimensional numerical model. To develop the numerical simulation of PEFC, verification experiments and data acquisition of physical parameters were conducted by mechanical measurements.
  • Special Issue on the 7th JSME-KSME Thermal and Fluids Engineering Conference Preface
    Takemi Chikahisa; Kazuhiko Kudo; Katsunori Hanamura; Yutaka Tabe
    JOURNAL OF THERMAL SCIENCE AND TECHNOLOGY, 2009, JAPAN SOC MECHANICAL ENGINEERS, English
    2009 - 2009
  • J0601-3-2 Liquid Water and Gas Flow Simulation in a Channel of PEM Fuel Cells Using the Lattice Boltzmann Method
    Yasser Ben Salah; Tabe Yutaka; Chikahisa Takemi
    The proceedings of the JSME annual meeting, 2009, The Japan Society of Mechanical Engineers, English
    2009 - 2009, Numerical simulations using the lattice Boltzmann method (LBM) are developed to elucidate the dynamic behavior of condensed water and gas flow in a polymer electrolyte membrane (PEM) fuel cell. Water management is essential to improve the performance of PEM fuel cells. Since it is difficult to investigate experimentally the liquid water behavior, we applied the lattice Boltzmann method for incompressible two-phase flow with large density difference and evaluate the liquid behavior in gas flow channels in a PEM fuel cell. In this paper, the effects of droplet position, air flow velocity and volume of liquid water droplet on the drain behavior and the efficiency were examined.
  • 514 LBM Simulation of Water Droplet Behavior in Complicated Fiber-like Structure in PEFC
    Sasaki Takayuki; Tabe Yutaka; Chikahisa Takemi
    The Proceedings of Conference of Hokkaido Branch, 2009, Japanese
  • 513 Dominant Effect Evaluation of Structure Parameters in PEFC Catalyst Layer on the Cell Performance
    NISHINO Masayoshi; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2009, Japanese
  • 512 Evaluation of 3-dimensional Numerical Simulation Code for PEFC by Comparison with Experimental Results
    SHIMODATE Takuya; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2009, Japanese
  • 511 MARKAL Analysis on Long-term Change of Residential Energy Equipment Structure in Japan
    KUROKAWA Shingo; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2009, Japanese
  • E132 Vaporizer for Low Volatile Organic Solvent for Semiconductor Reactors
    Miyata Noritsugu; Kikuta Kazushige; Tabe Yutaka; Chikahisa Takemi
    The Proceedings of the Thermal Engineering Conference, 2009, Japanese
    The phenomenon in the vaporizer for low volatile organic solvent is analyzed and the performances of the two types of vaporizer are evaluated. The numerical simulation shows that the vaporizer using a two-fluid nozzle cannot fully utilize the tube space because of the strong penetration characteristic and the low adjusting capability of the flow pattern. The vaporizer with ultrasonic nozzle and gas inlets is presented to avoid the disadvantages above. It is demonstrated that the ultrasonic nozzle type can achieve more than 6 times particle residence time as compared with the two-fluid nozzle type and it can be applied for the evaporator of the low volatile organic solvents.
  • D206 Long-term CO_2 Emission Analysis on Energy Structures in Japan
    TABE Yutaka; UNO Kouta; CHIKAHISA Takemi
    The Proceedings of the National Symposium on Power and Energy Systems, 2009, Japanese
    Long-term CO_2 emission analyses on the energy structure in Japan were conducted using the MARKAL. The MARKAL model is one of analysis tools to evaluate the long-term change of energy system in a country, and is composed of energy resources, energy supply technologies, energy ultimate demand technologies and energy service demands with them connected by energy carriers. This paper presents the analyses investigating energy structure at house and effects of CO_2 capture and storage (CCS) until 2050. It was shown that the usage of electricity and gas is strongly affected by the investment costs, and the large reduction is needed for CGS widespread use. The results also showed that the CCS is effective in the case that the installed capacity of nuclear power plant, and the effective capture of CO_2 reduces the social costs for the reduction of CO_2 emission.
  • F102 Performance and Liquid Water Distribution in PEFC with Anisotropic GDL
    Soe Naing Kyaw Swar; Kikuta Kazushige; Tabe Yutaka; Chikahisa Takemi
    The Proceedings of the National Symposium on Power and Energy Systems, 2009, English
  • J0601-3-1 Liquid Water and Gas Flow Simulation in a Porous Medium of PEM Fuel Cells using the Lattice Boltzmann Method
    TABE Yutaka; LEE Yongju; YASSER Ben Salah; CHIKAHISA Takemi
    The Proceedings of Mechanical Engineering Congress, Japan, 2009, Japanese
    The simulation using the lattice Boltzmann method (LBM) has been developed to understand the behavior of liquid water and gas flow in porous media of PEM fuel cells. The original LBM code was parallelized and a increase in solving speed of the Poisson equation was made by the conjugate gradient (CG) method for the large-scale simulation. Some validation calculations were conducted and the rate of speeding up was verified. Using the parallelized LBM code with the CG method, the behavior of liquid water in a gas diffusion layer was simulated and the applicability of our code to two-phase simulation in a porous medium of PEM fuel cells are presented.
  • High-speed diesel combustion model for transient simulation of after-treatment systems
    Kazushige Kikuta; Yutaka Tabe; Takemi Chikahisa; Yusuke Takashima
    Proceedings of the 7th International Conference on Modeling and Diagnostics for Advanced Engine Systems, COMODIA 2008, 01 Dec. 2008
    01 Dec. 2008 - 01 Dec. 2008, To design diesel engines adapted to future exhaust gas regulations, it would be advantageout to have a driving mode simulator for vehicle performance and exhaust emissions, including after-treatment systems. A driving mode simulator with simple and high-speed calculation characteristics was developed with a diesel combustion model based on the Hiroyasu model. In the air entrainment model this report adds the effect of the air entrainment due to turbulent flow in a cylinder, and in the ignition delay model we considered the partial pressure of oxygen for better fitting the EGR effect. To simulate premixed compression ignition engines, the Schreiber's reduced kinetic model for ignition and combustion was also included. Arrhenius parameters for the rate constants were modified to fit the ignition delay. As a result it was possible to simulate low-temperature oxidation and the main combustion. The paper details the modifications and demonstrates the usefulness of the modified model by comparisons with experimental results. Copyright © 2008 by the Japan Society of Mechanical Engineers.
  • 2121 Analysis of electrode catalyst layer using three-phase boundary model for Pt high utilization in PEMFC
    TAKAMATSU Hiroyuki; TABE Yutaka; KIKUTA Kazusige; CHIKAHISA Takemi
    The Proceedings of Mechanical Engineering Congress, Japan, 02 Aug. 2008, Japanese
    To decrease the usage of the Pt catalyst in polymer electrolyte membrane fuel cell (PEMFC), optimization of catalyst layer structure and three-phase zone is one of key issues. In this study, numerical simulation was conducted to investigate the relation between the structure of cathode catalyst layer and cell performance (over voltage and current density). From the calculation results, suitable structures, porosity and polymer electrolyte thickness, for gas diffusion and proton conduction were clarified.
  • 2302 Analysis of NOx Reduction Effect in Diesel Combustion by Mixing Control
    KASHIWASE Koji; KIKUTA Kazushige; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Mechanical Engineering Congress, Japan, 02 Aug. 2008, Japanese
    Experiment and numerical simulation indicated that the large NOx formation in diesel engine is due to the weak mixing intensity in the spray tip region, where the flow and turbulence structure is quite different from the continuous jet flames. The fact indicates that there is a possibility of reducing NOx from diesel engines by enhancing mixing intensity at the spray tip region to the level of continuous jet flame. This paper presents the analysis of NOx formation in diesel engines using HTB-DECS to confirm the effect of pre-shock jet. This analysis performed by changing the magnitude and/o...
  • F105 Investigation of porous flow field for Polymer Electrolyte Fuel Cell
    KOZAKAI Masaya; OKUSAWA Tsutomu; SATAKE Hiroyuki; TAKAHASHI Ko; TABE Yutaka; CHIKAHISA Takemi
    National Symposium on Power and Energy Systems, 18 Jun. 2008, Japanese
    High power density enhances polymer electrolyte fuel cell with widely varied applications. Our investigation focused on the refinement of the reactant gas flow field at the bipolar plate in order to increase the fuel cell performance. Applying a porous material to the reactant gas flow field is one possible method. Expected advantages of a porous flow field are an increase in reactant gas diffusivity and electron conductivity allover the electrode. An investigation was carried out to evaluate the feasibility of a porous flow field. The Lattice Boltzman simulation indicated that surface wett...
  • F104 Effect of Gas Diffusion Layer Characteristics on Gas-liquid Flow and Performance in PEFC
    YAMASHITA Kouhei; KIKUTA Kazushige; TABE Yutaka; CHIKAHISA Takemi
    National Symposium on Power and Energy Systems, 18 Jun. 2008, Japanese
    To maintain the high performance in PEFC, water management which keep an electrolyte film to the adequate wet is necessary. The gas diffusion layer (GDL) fulfils large role in it. In this study cell characteristics was tested using GDL with various characteristics. As a result it was showed that the rigidity was necessary for GDL to keep the contact resistance stably low. In GDL with the same carbon-fiber direction, the difference of the cell performance occurred by changing the channel direction. It was thought that the gas diffusion under the separator rib was changed, because the differe...
  • F101 Experimental Data Acquisition for Numerical Simulation of PEM Fuel Cell, and Analysis of Flooding Phenomenon by Electrochemical Measurement
    SAITO Masataka; TABE Yutaka; KIKUTA Kazushige; CHIKAHISA Takemi
    National Symposium on Power and Energy Systems, 18 Jun. 2008, Japanese
    To develop the numerical simulation of PEM fuel cell, verification experiments and data acquisition of physical parameters were conducted by mechanical and electrochemical measurements. The mechanical measurement showed that the GDL deformation due to clamping by separator lands is important phenomenon to estimate an actual flow in the cell, and the unique deformation behavior of GDL with fabric construction was clarified. From the electrochemical measurement, the methods to acquire the parameters used in the simulation, proton conductivity σ_m, electrochemically active Pt area a, exchange ...
  • Analysis of Future Vehicle Composition Structures and CO_2 Emissions in Japan and China Based on Automobile Selection Model for Consumers
    SENO Kenji; TABE Yutaka; CHIKAHISA Takemi
    エネルギーシステム・経済・環境コンファレンス講演論文集 = Proceedings of the ... Conference on Energy, Economy, and Environment, 30 Jan. 2008, Japanese
  • EXPERIMENTAL EVALUATION OF AIR FLOW EFFECT IN GAS DIFFUSION LAYER ON PEM FUEL CELL PERFORMANCE
    Yutaka Tabe; Daisuke Yoshida; Kazushige Kikuta; Takemi Chikahisa; Masaya Kozakai
    PROCEEDINGS OF THE 6TH INTERNATIONAL CONFERENCE ON FUEL CELL SCIENCE, ENGINEERING, AND TECHNOLOGY - 2008, 2008, AMER SOC MECHANICAL ENGINEERS, English
    2008 - 2008, This paper investigated the effects of gas and liquid water flow on the performance of a polymer electrolyte membrane (PEM) fuel cell using cells to allow direct observation of the phenomena in the cell and measurements of the local current density and the local pressure loss. The experimental results to compare the separator type indicated the effect of cross-over flow in the gas diffusion layer (GDL) under the lands of serpentine separators on cell performance and the potential of straight channel separator to achieve a relatively-uniform current density distribution. To evaluate the crossover flow under the land of serpentine separators, a simple circuit model of the gas flow was developed. This analysis showed that slight variations in oxygen concentration caused by the cross-over flow under the land affect the local and overall current density distributions. It was also shown that the establishment of gas paths in the deep layer of GDL by the channels filled with condensed water is effective for stable operation at low flow rates of air in the straight channels.
  • G211 Analysis of CO_2 Emission in Prospective Distributed Energy Systems with CGS and Heat Pump
    Soe Naing Kyaw Swar; Tabe Yutaka; Chikahisa Takemi
    Procee[d]ings of Thermal Engineering Conference, 23 Nov. 2007, English
    This paper analyzes the effectiveness of CGS for the CO_2 and cost reductions in the prospective distributed energy system, which is a future type system using heat pump for heating instead of boiler. The CGS effectiveness in different building types and regions are discussed, where COP dependencies on the ambient temperature and demands of heating or cooling are considered. The results show that CO_2 reduction effect of CGS in the prospective system is lower than that in the conventional system but the cost reduction effect is higher. It was also shown that the prospective CGS is more adva...
  • OS5-4 Characteristics of Gas-Liquid Flow in PEM Fuel Cell and its Effect on Current Dencity Distribution and Cell Performance
    YOSHIDA Daisuke; YASUDA Yousuke; TABE Yutaka; KIKUTA Kazushige; CHIKAHISA Takemi; KOZAKAI Masaya
    National Symposium on Power and Energy Systems, 13 Jun. 2007, Japanese
    The objective of this paper is to observe water production behavior inside of the cell and to analyze its effect on current distributions over the reaction area. A fuel cell was made to allow direct observation of the phenomena in cathode side and local current density measurement in anode side. The experimental results showed that the cell performance and current density distribution of air operation is strongly affected by the condensed water compared with those of O_2 operation, although the drainage of air operation is superior. It was also shown from the comparison experiments of separ...
  • Evaluation of Long Term CO_2 Balance and Fire Control Method in Siberia Using Forest Fire Model
    KAKAZU Kei; TABE Yutaka; CHIKAHISA Takemi
    エネルギーシステム・経済・環境コンファレンス講演論文集 = Proceedings of the ... Conference on Energy, Economy, and Environment, 25 Jan. 2007, Japanese
  • Numerical simulation of liquid water and air flow in separator-channels in PEM fuel cell using LBM
    Yutaka Tabe; Kohsuke Kibo; Kazushige Kikuta; Takemi Chikahisa; Masaya Kozakai
    PROCEEDINGS OF THE ASME/JSME THERMAL ENGINEERING SUMMER HEAT TRANSFER CONFERENCE 2007, VOL 2, 2007, AMER SOC MECHANICAL ENGINEERS, English
    2007 - 2007, In a polymer electrolyte membrane (PEM) fuel cell, the condensed water in the separator-channel prevents the supply of reactants to electrodes, which deteriorates the cell performance. The Lattice Boltzmann simulation has been developed to understand the behavior of condensed water in the separator-channels. The calculation process was improved, and the effect on the stability and reliability of simulation of two-phase flows with large density difference was confirmed. Further, the comparison with experiment of the falling water droplet by gravitation on the slope of micro porous layer was conducted to validate effectiveness of the improved simulation. It was shown that the simulation can express the increase in falling speed of water droplet and the effect of inclined angle of the slope, and our simulation is effective enough to estimate the liquid water and air flow in the separator-channel. Finally, the simulation of liquid water behaviors in separator-channels with various cross-sectional shapes was conducted, and the drain efficiency of water droplet of separator-channel was discussed.
  • Basic study and engine trial on diesel NOx reduction by controlling mixing
    Yutaka Tabe; Takemi Chikahisa
    SAE Technical Papers, 2007, English
    2007 - 2007, This paper investigates the effect of enhancing mixing of spray tip region on NOx reduction from diesel engines. The concept is based on the fact that dominant part of NOx formation is the flame tip region with weak mixing intensity. Two methods to realize our concept were attempted in a constant volume combustion bomb and in an actual diesel engine. One is the two-stage injection and another is the method with a jet created by combustion of premixed charge in a turbulence cell. The paper presents results of variety trials of experiment, and it discusses necessary means to achieve the concept. Copyright © 2007 Society of Automotive Engineers of Japan, Inc.
  • 107 Study on three-phase zone model of PEFC for the Pt high-efficient utilization
    TAKAMATSU Hiroyuki; TABE Yutaka; KIKUTA Kazusige; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2007, Japanese
  • 108 Numerical Simulation of Liquid Water Behavior in PEM Fuel Cell using Lattice Boltzmann Method
    Lee Yongju; Kibo Kohsuke; Tabe Yutaka; Kikuta Kazusige; Chikahisa Takemi
    The Proceedings of Conference of Hokkaido Branch, 2007, Japanese
  • 511 Study on simple and high-speed diesel combustion model for driving mode simulator
    Takashima Yusuke; Chikahisa Takemi; Tabe Yutaka; Kikuta Kazusige
    The Proceedings of Conference of Hokkaido Branch, 2007, Japanese
  • 513 Evaluation of long term CO_2 balance and fire control method in Siberia using forest fire model
    UNO Kouta; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2007, Japanese
  • B141 Analysis of CHP Effectiveness for Different Power Plant Efficiencies
    Soe Naing Kyaw Swar; Tabe Yutaka; Chikahisa Takemi
    Procee[d]ings of Thermal Engineering Conference, 23 Nov. 2006, English
    This paper analyzes CGS effectiveness for the CO_2 reduction, and the effects of use of heat pump for heating were investigated at various power plant efficiencies and the COP of heat pump. In the next-generation, it is essential to apply the system with heat pump for heating instead of boiler. The calculation results show that CGS benefit for CO_2 emission is strongly affected by the COP of heat pump and the electric efficiency of CGS is needed to be close to that of power plant efficiency to have a beneficial effect in the prospective system with heat pump. The electrical efficiency of CG...
  • 4406 Influence of Demand Fluctuation and Improved System in Individual Installation of Cogeneration at House
    TABE Yutaka; IWASA Yoshitaka; CHIKAHISA Takemi
    The Proceedings of Mechanical Engineering Congress, Japan, 15 Sep. 2006, Japanese
    This paper analyzes primary energy reduction effect of cogeneration system (CGS) installed at individual house with large demand fluctuation, and discusses its improved system. The start-stop operation considering the start-up energy of CGS and heat radiation of thermal storage unit was proposed as a better operation method of CGS installed at individual house. It was shown from the analysis using the actual energy demand pattern of six houses that the start-stop operation is available and electricity network has mitigation effect of large demand fluctuation to increase the primary energy r...
  • 4710 NO_x Reduction Experiment by Mixing Control in a Diesel Engine
    OTSU Sho; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Mechanical Engineering Congress, Japan, 15 Sep. 2006, Japanese
    This paper presents results of two different trials to reduce NO_x from diesel engines: one is pre-shock injection method and the other is the method with pre-shock jet created by using premixed charge combustion. The both concepts are based on the fact that dominant part of NO_x formation is the area close to the spray tip, where mixing intensity is weak. The mixing intensity of this area is to be maintained high by the two methods. The result shows reasonable effect for the reduction of NO_x, but the extent was not as significant as expected. It was found that the pre-shock jet was not re...
  • STUDY ON FREEZING PHENOMENA IN PEM FUEL CELL BELOW FREEZING
    Tabe, Y; Nakamiya, H; Kikuta, K; Chikahisa, T; Kagami, F; Yoshizawa, K
    Proceedings of 13th International Heat Transfer Conference, 2006, English
    2006 - 2006
  • Measurement of water production phenomena, temperature, and current density distributions in a polymer electrolyte fuel cell
    Takemi Chikahisa; Yutaka Tabe; Kazushige Kikuta; Naofumi Nohara; Hideki Shinohara
    Proceedings of the 4th International Conference on Fuel Cell Science, Engineering, and Technology, Pts A and B, 2006, AMER SOC MECHANICAL ENGINEERS, English
    2006 - 2006, This paper observes phenomena related to water production behavior inside a fuel cell and analyzes the effect on the current and temperature distribution across the reaction area. A fuel cell permitting direct observation of the phenomena in the cell, 2-D temperature measurements in the cathode channels, and local current density measurements on the anode side was manufactured. The experimental results showed the production and flow of liquid water in the cell, and there were good correlations among the distributions of current density, temperature, and water amounts in the channels. The behavior of current, voltage, water distribution, and pressure differences in the cathode channels were used to hypothesize about the possibility of gas paths deep in the gas diffusion layer in the flooded condition and a positive feedback mechanism in the drying-out condition.
  • Development of a Combustion Model for a High-Speed Total Engine Simulation System
    荒戸景太; 近久武美; 田部豊; 菊田和重; 金子友海; 港明彦; 島崎直基
    自動車技術会学術講演会前刷集, 2006
    2006 - 2006
  • Future vehicle composition structures and CO2 emissions based on automobile selection model for consumers
    T Chikahisa; Y Tabe; M Yamauchi
    PROCEEDINGS OF THE SECOND IASTED INTERNATIONAL CONFERENCE ON ADVANCED TECHNOLOGY IN THE ENVIRONMENTAL FIELD, 2006, ACTA PRESS, English
    2006 - 2006, Increases in CO2 emissions from vehicles is a major concern in automotive societies, and a variety of car types offering lower CO2 emissions, hybrid cars, natural gas cars, electric cars, and cars with fuel-cell, are being investigated intensively. However the level of performance and cost that must be achieved for future cars to be acceptable in the market and the percentage of cars that must be replaced for the protection of the environment is not clear. This paper investigates future market growth of low-emission vehicles and analyzes CO2 emission changes for passenger cars in Japan, England, and the United States. A consumer model for selecting vehicles, which was established in the previous report, was calibrated with statistical data from each of the countries. The results of the analysis shows that England has the highest potential for reducing CO2 emissions among these countries, but that this is stili insufficient to accomplish the Kyoto protocol requirements. Market shares of low emission vehicles are similar in Japan and England, and hybrid cars appear to be able to reach a substantial shares in 10 years, while the share of fuel cell powered cars will be very small. The critical cost for fuel eel I powered cars to gain a 10% share in 2015 is shown for the three countries.
  • 515 Evaluation of Forest Fire Model and Effects of Increasing Fires on Long Term CO_2 Balance in Siberia
    KAKAZU Kei; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Conference of Hokkaido Branch, 2006, Japanese
  • 509 Numerical Simulation of Liquid Water Behavior in Separator-Channels in PEFC using LBM
    Kibo Kohsuke; Tabe Yutaka; Kikuta Kazusige; Chikahisa Takemi
    The Proceedings of Conference of Hokkaido Branch, 2006, Japanese
  • G121 Dry-out conditions of free-breathing PEM fuel cells with dry H_2 gas
    PARK Sangkyun; KIKUTA Kazushige; TABE Yutaka; CHIKAHISA Takemi
    Procee[d]ings of Thermal Engineering Conference, 02 Nov. 2005, Japanese
    This study investigates drying condition for the case when a small fan is added to a free-breathing proton electrolyte membrane fuel cell (PEMFC) operating with dry H_2 and air. Polarization tests were conducted on PEMFCs at cell temperatures between 30 and 50℃. The result shows that the cell performance strongly depends on the cell temperature and the stoichiometric flow-rates of cathode gas. The cell performance increases as cell temperature decreases from 50 to 30℃. In the condition where the air flow-rate is quite large, internal resistance increases due to the progress of drying, but i...
  • 3619 Study on Freezing Phenomenon in Polymer Electrolyte Fuel Cell below Freezing
    NAKAMIYA Hiromitsu; KIKUTA Kazusige; TABE Yutaka; CHIKAHISA Takemi; KAGAMI Fumio; YOSHIZAWA Koudai
    The Proceedings of Mechanical Engineering Congress, Japan, 18 Sep. 2005, Japanese
    In PEFC at low temperature, the freezing of produced water induces the extreme deterioration of cell performance. The characteristics of start-up below freezing in a wide variety of current densities was investigated and the cell impedance measurements was conducted to clarify the freezing phenomenon in PEFC. It was confirmed that the characteristics can be related to the amount of produced water and the rise in cell temperature by reaction. It was also showed that increase of reaction resistance, which was considered to be mainly due to increase gas transfer resistance, has much effect on ...
  • 3618 Simultaneous Measurement of Mass and Heat Transfer Phenomena and Current Density Distribution in PEFC
    NOHARA Naofumi; KIKUTA Kazusige; TABE Yutaka; CHIKAHISA Takemi
    The Proceedings of Mechanical Engineering Congress, Japan, 18 Sep. 2005, Japanese
    A fuel cell was made to allow direct observation of the phenomena in the cell, 2-D temperature measurement in cathode channels, and local current density measurements in anode side. The experimental results showed good correlation among direct view in the cell, temperature distribution and local current density. The experiment indicates transition phenomena of dry out and flooding depending on the flow and current conditions. The results suggests the possibility of different current density distribution for the same experimental conditions depending on the previous MEA condition history.
  • 436 Mapping Method of CO_2 and Cost Reduction of Cogeneration System
    IWASA Yoshitaka; TABE Yutaka; CHIKAHISA Takemi
    Symposium on Environmental Engineering, 06 Jul. 2005, Japanese
    This paper presents mapping method to show characteristics of cogeneration systems (CGS) for the reduction of carbon dioxide emission and economy. In this method, effects of CGS can be consolidated into rated reduction ratio, relative reduction ratio map, demand repetition map and weight map. By lapping these maps, it can be easy to evaluate compatibility with each building types and optimal installed capacity. Analyzed charts are useful to evaluate quantitative effects of CGS for various areas and price rates of electric/gas from average annual demand of electricity and heat.
  • 327 Modeling of Forest Fire and Evaluation of the Fire Effects on Long Term CO_2 balance in Siberia
    CHIKAHISA Takemi; TABE Yutaka; KAWAGUCHI Hajime
    Symposium on Environmental Engineering, 06 Jul. 2005, Japanese
    Forest in Siberia plays important role for absorbing carbon dioxide. However, resent increase in forest fires, due to both human negligence and global warming, appears to cause significant damage on the forest. The present research tries to establish simulation model, which enables to predict forest fire effect over thousand years, and to evaluate the effects of forest fire on long term balance of CO_2 in Siberia. The result of the analysis shows that the major factor affecting on long-term forest area is the probability of fire extension and the number of fires in a year would not make app...
  • Evaluation of Forest Fire Model and Effects of Increasing Fires on Long Term CO_2 balance in Siberia
    KAWAGUCHI Hajime; TABE Yutaka; CHIKAHISA Takemi
    エネルギーシステム・経済・環境コンファレンス講演論文集 = Proceedings of the ... Conference on Energy, Economy, and Environment, 26 Jan. 2005, Japanese
  • Numerical simulation of liquid water behavior in separator-channels in PEMFC using LBM
    Yutaka Tabe; Takamichi Ochi; Kazushige Kikuta; Takemi Chikahisa; Hideki Shinohara
    Proceedings of the 3rd International Conference on Fuel Cell Science, Engineering, and Technology, 2005, AMER SOC MECHANICAL ENGINEERS, English
    2005 - 2005, In a polymer electrolyte membrane fuel cell, the condensed water in the separator-channel prevents the supply of reactants to electrodes, which deteriorates the cell performance. The Lattice Boltzmann simulation has been conducted to understand the behavior of condensed water in the separator-channels. The scheme for the two-phase flow with large density difference was applied and the boundary condition for wettability at the corner inside the channel was examined. The present simulation demonstrates the effects of the cross-sectional shape, the wettability of channel and the volume of condensed water on the liquid water behavior. In the hydrophilic separator-channels, the liquid water spreads along the channel wall to form film and, in a specific condition, the water draws away from the gas diffusion layer, which suppresses the flooding. On the other hand, the liquid water forms sphere, covering larger area of the surface of gas diffusion layer in the hydrophobic separator-channels, but the drain performance of liquid water is superior.
  • 411 Study on NOx Reduction in Diesel Combustion by Controling Mixing
    OTSU Sho; CHIKAHISA Takemi; TABE Yutaka
    The Proceedings of Conference of Hokkaido Branch, 2005, Japanese
  • Formation of liquid CO2 droplets and jets with deformation and growth of hydrate film
    S Hirai; R Takamatsu; Y Tabe; K Suzuki; K Okazaki
    GREENHOUSE GAS CONTROL TECHNOLOGIES, 2001, English
    2001 - 2001
  • Advanced CO2 ocean dissolution technology for longer term sequestration with minimum biological impacts
    S Hirai; Y Tabe; G Tanaka; K Okazaki
    GREENHOUSE GAS CONTROL TECHNOLOGIES, 1999, English
    1999 - 1999
  • Measurement of clathrate-hydrate film thickness formed at the interface between liquid CO2 and water
    Y Tabe; S Hirai; K Okazaki
    GREENHOUSE GAS CONTROL TECHNOLOGIES, 1999, English
    1999 - 1999
■ Syllabus
  • エネルギー環境システム特別研究, 2024年, 博士後期課程, 工学院
  • エネルギー環境システム工学特別ラボラトリーセミナー, 2024年, 修士課程, 工学院
  • エネルギー環境システム特別演習, 2024年, 修士課程, 工学院
  • グローバル実践科目Ａ, 2024年, 修士課程, 工学院
  • グローバル実践科目Ｂ, 2024年, 修士課程, 工学院
  • 大学院共通授業科目（教育プログラム）：One program for Global Goals, 2024年, 修士課程, 大学院共通科目
  • エネルギー技術・政策特論, 2024年, 修士課程, 工学院
  • 大学院共通授業科目（一般科目）：自然科学・応用科学, 2024年, 修士課程, 大学院共通科目
  • 原子力・エネルギーシステム特論, 2024年, 修士課程, 工学院
  • 大学院共通授業科目（教育プログラム）：One program for Global Goals, 2024年, 修士課程, 大学院共通科目
  • エネルギー環境システム工学特別ラボラトリーセミナー, 2024年, 博士後期課程, 工学院
  • エネルギー環境システム特別研究, 2024年, 博士後期課程, 工学院
  • グローバル実践科目Ａ, 2024年, 博士後期課程, 工学院
  • グローバル実践科目Ｂ, 2024年, 博士後期課程, 工学院
  • エネルギー技術・政策特論, 2024年, 博士後期課程, 工学院
  • 原子力・エネルギーシステム特論, 2024年, 博士後期課程, 工学院
  • 専門横断科目（一般科目）：複合領域, 2024年, 学士課程, 専門横断科目
  • エネルギー工学概論, 2024年, 学士課程, 工学部
  • 専門横断科目（一般科目）：複合領域, 2024年, 学士課程, 専門横断科目
  • 熱力学Ⅰ, 2024年, 学士課程, 工学部
  • 熱力学Ⅱ, 2024年, 学士課程, 工学部
  • 熱流体力学演習Ⅰ, 2024年, 学士課程, 工学部
  • 環境エネルギー工学, 2024年, 学士課程, 工学部
  • 熱流体力学演習Ⅱ, 2024年, 学士課程, 工学部
■ Affiliated academic society
  • The Electrochemical Society
  • JAPAN SOCIETY OF ENERGY AND RESOURCES
  • SOCIETY OF AUTOMOTIVE ENGINEERS OF JAPAN
  • THE HEAT TRANSFER SOCIETY OF JAPAN
  • THE JAPAN SOCIETY OF MECHANICAL ENGINEERS
■ Research Themes
  • Control of interfacial condensed water in PEM fuel cells for higher power output and wider operation temperatures
    Grants-in-Aid for Scientific Research
    01 Apr. 2024 - 31 Mar. 2027
    田部 豊; 植村 豪; 青山 祐介
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 24K00811
  • リチウム空気電池の高効率酸素輸送と高出力化を実現するIonomer被覆電極の構築
    科学研究費助成事業
    01 Apr. 2024 - 31 Mar. 2027
    植村 豪; 田部 豊; 青山 祐介
    日本学術振興会, 基盤研究(B), 北海道大学, 24K00812
  • リチウム空気電池内電解液濡れ現象のCryo-SEM観察と高性能電極構造の解明
    科学研究費補助金(基盤研究(B))
    2021 - 2023
    植村 豪; 田部 豊
    文部科学省, Coinvestigator
  • PEM燃料電池の高出力化のためのマルチスケール水・酸素輸送促進
    科学研究費補助金(基盤研究(B))
    2021 - 2023
    田部 豊; 植村 豪; 境田 悟志
    文部科学省, Principal investigator
  • PEM形燃料電池の氷点下起動におけるマルチスケール水輸送・凍結分布制御
    科学研究費補助金(基盤研究(B))
    2017 - 2019
    田部 豊; 近久 武美
    文部科学省, Principal investigator, Competitive research funding
  • PEM形燃料電池内のナノスケール水輸送現象観察と高性能電池構造の解明
    科学研究費補助金(基盤研究(B))
    2016 - 2018
    近久 武美; 田部 豊; 大島 伸行
    文部科学省, Coinvestigator, Competitive research funding
  • 大規模高効率化のためのレドックスフロー電池活物質輸送現象の解明
    科学研究費補助金(基盤研究(C))
    2014 - 2016
    田部 豊
    文部科学省, Principal investigator, Competitive research funding
  • 凍結固定化法による固体高分子形燃料電池内の反応および気液輸送機構の解明
    科学研究費補助金(基盤研究(B))
    2012 - 2014
    近久 武美; 田部 豊; 鈴木 研悟
    文部科学省, Coinvestigator, Competitive research funding
  • Elucidation of Micro and Nano Freezing in Catalyst Layer and Water Transfer in PEFC
    Grants-in-Aid for Scientific Research
    2011 - 2013
    TABE Yutaka
    The objective of this study is to elucidate the freezing mechanism in the catalyst layer (CL) at cold start and water transport phenomena in the vicinity of the micro-porous layer (MPL) in PEFC. The freezing model was developed, and the detailed observation of the MPL cross-section was conducted. These showed that the ice distribution formed during the -20 degree C cold start strongly depends on the current density, but not on the oxygen supply condition. This study also identified the factor controlling the ice distribution, and the liquid water distribution under normal operations above freezing temperature.
    Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists (A), Hokkaido University, Principal investigator, Competitive research funding, 23686034
  • Study on the transport phenomena of gas and liquid in gas diffusion layers in PEM fuel cell and freezing mechanism in cold start
    Grants-in-Aid for Scientific Research
    2009 - 2011
    CHIKAHISA Takemi; TABE Yutaka
    The objective of the research is to clarify the transport phenomena in polymer electrolyte membrane fuel cells (PEMFC) by means of observing inside of the cell with freezing method, measuring current density distribution, and simulating water behavior with LBM method. The results of the research revealed detailed functions of GDL and MPL layers on the water transport, major parameters controlling the performance in the catalyst layers, freezing phenomena in cold starts, and optimal configurations of gas channels for the water discharge.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, Coinvestigator, Competitive research funding, 21360089
  • Two Phase Flow Simulation of Gas and Liquid in the Porous Structures and the Channels of PEM Fuel Cells
    Grants-in-Aid for Scientific Research(若手研究(B))
    2009 - 2010
    Yutaka TABE
    This study developed the three dimensional lattice Boltzmann simulation code of the two phase flow in a PEM fuel cell. The objective is to evaluate the gas and liquid behavior in the complicated porous structures and to present optimum cell structures. The developed code clarified the effects of wettability of gas diffusion layer on the drain behavior of condensed water. The simulation also indicated that hydrophilic ribs of separator improves the drainage performance of the gas diffusion layer.
    Ministry of Education, Culture, Sports, Science and Technology, 若手研究(B), 北海道大学, Principal investigator, Competitive research funding, 21760146
  • Numerical Analysis of Electrode Catalyst Layer in PEMFC UsingThree-phase Boundary Model for Pt High Utilization
    Grants-in-Aid for Scientific Research(若手研究(B))
    2007 - 2008
    Yutaka TABE
    白金の高効率利用に適した触媒層を明らかにすることを目的として、3相界面モデルおよび触媒層モデルを作成し解析を行った。さらに異なる高分子電解質を用いて模擬触媒層を作成し簡易実験を行った。これより、高分子電解質量、空隙率などの触媒層構造が電池性能に及ぼす影響を定量的に明らかにするとともに、高分子電解質中への酸素の溶解度上昇が電池性能向上に著しく寄与し、少ない白金担持量でも高い電池性能を得られる可能性があることを示した。
    Ministry of Education, Culture, Sports, Science and Technology, 若手研究(B), 北海道大学, Principal investigator, Competitive research funding, 19760127
  • Study on the transfer phenomena of gas, liquid, heat, and electron in a cell for the development of high performance PEM fuel cell available in low temperature conditions
    Grants-in-Aid for Scientific Research(基盤研究(B))
    2005 - 2007
    CHIKAHISA Takemi; TABE Yutaka; KIKUTA Kazushige
    This study has been conducted to clarify the mass, heat, electron transport phenomena in gas diffusion layers (GDLs) in fuel cell. Using an optical fuel cell, temperature distribution in cathode channel and current density distribution in anode channel was investigated. The experimental results showed that there is good correlation between the temperature distribution and the current density distribution, and uniformity of the contact pressure strongly influences the temperature and current density distributions. The observation result indicated that there is a condition when gas paths are ...
    Ministry of Education, Culture, Sports, Science and Technology, 基盤研究(B), 北海道大学, Coinvestigator, Competitive research funding, 17360089
  • 固体高分子形燃料電池内での水分凍結挙動の可視化
    科学研究費補助金(若手研究(B))
    2005 - 2006
    田部 豊
    氷点下での固体高分子形燃料電池の起動特性に及ぼす起動前残留水分量ならびに運転条件の影響を実験的に明らかにするとともに、電池内の凍結機構に関する考察を行った。得られた主な知見は以下の通りである。1.セル内水分量がある程度以上ある場合には、冷却中に凍結が起り、低温起動時問が極端に短くなる。ここで、冷却中の凍結は、赤外線サーモグラフィーによる熱画像、またはセル抵抗の変化から検地することが可能である。本実験では冷却中に凍結が起こる水分量の閾値は約1mg/cm^2であった。このことより、低温起動においてはその停止条件、すなわち運転停止後のセル内の水分管理が重要であると言える。2.低温起動から生成水凍結開始までの時間は拡散層の構造の違いによる影響を受け、起動温度-10℃程度では、凝縮水圧力及び温度が高い触媒層近傍に生成水を溜め込みやすいカーボンペーパーのほうが、生成水が拡散層側へ移動しやすいカーボンクロスに比べて生成水の凍結が遅くなる傾向があった。これは、圧力および温度が高い凝縮水が過冷却状態で保持され易いためと考えられる。一方、起動温度-20℃では、カーボンペーパーとカーボンクロスの凍結開始までの時間に及ぼす影響は小さくなった。これは、より低温であることでペーパーにおいても過冷却がほとんど起こらなくなったためと考えられる。3.凝縮水が、MEA-GDL界面に貯留する場合には上述した理由で...
    文部科学省, 若手研究(B), 北海道大学, Principal investigator, Competitive research funding, 17760153
  • 超高圧固体水和物を伴う液体CO2の物質移動現象の解明とCO2海洋貯留の制御
    科学研究費助成事業
    1998 - 1999
    田部 豊
    日本学術振興会, 特別研究員奨励費, 東京工業大学, 97J04427

Research Profiles

■ Research Profiles