• Title/Summary/Keyword: Hydrogen Fuel Cell System

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DC/DC Converter Design for 7kW Fuel Cell (7kW 연료전지용 DC/DC 컨버터 설계)

  • Kim, Ga-In;Shin, Min-Ho;Lee, Jung-Hyo
    • The Transactions of the Korean Institute of Power Electronics
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    • v.27 no.2
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    • pp.150-156
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    • 2022
  • This study proposes a design method of fuel cell DC/DC converter using in 5-ton forklift. For efficient hydrogen usage, targeted fuel cell system recirculates discarded hydrogen after fuel cell reaction. Recirculating hydrogen contains much impurities that reduces output power, increasing pressure that can damage the internal fuel cell reaction system. The proposed DC/DC converter effectively converts fuel cell power considering the voltage drop rate to reflect the recirculating hydrogen. Then, frequency control method is used to regulate the current ripple amount for battery and fuel cell hybrid configuration. Proposed power converter system design and control methods are verified in a practical fuel cell system that implements recirculating hydrogen.

Flow analysis of the Hydrogen Recirculation System for Fuel Cells (연료전지 수소 재순환 시스템의 유동해석)

  • Kim, Jae-Choon;Lee, Yong-Taek;Chung, Jin-Taek;Kim, Yong-Chan;Hwang, In-Chul
    • 유체기계공업학회:학술대회논문집
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    • 2005.12a
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    • pp.759-764
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    • 2005
  • In this paper, numerical analysis of hydrogen recycle system has been conducted in order to enhance the efficiency of automotive fuel cell. Generally, the excess hydrogen is provided in the automotive fuel cell. Since the non-reaction hydrogen reduces automotive fuel cell efficiency, reuse of the non-reaction hydrogen can be helpful to improve the fuel cell performance. In case of PEM FC, the water vapor is provided to hydrogen from the cathode so that the mixture experiences phase change depending on the changes of pressure and temperature. The internal flow of the mixture in the hydrogen recirculation system of fuel cell was investigated for real flow conditions. The variation of performance, properties and mass fractions of mixture, hydrogen and water-vapor were investigated. This study was performed based on 80KW level automotive fuel cell's recycling system.

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Power Distribution Optimization of Multi-stack Fuel Cell Systems for Improving the Efficiency of Residential Fuel Cell (주택용 연료전지 효율 향상을 위한 다중 스택 연료전지 시스템의 전력 분배 최적화)

  • TAESEONG KANG;SEONGHYEON HAM;HWANYEONG OH;YOON-YOUNG CHOI;MINJIN KIM
    • Journal of Hydrogen and New Energy
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    • v.34 no.4
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    • pp.358-368
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    • 2023
  • The fuel cell market is expected to grow rapidly. Therefore, it is necessary to scale up fuel cells for buildings, power generation, and ships. A multi-stack system can be an effective way to expand the capacity of a fuel cell. Multi-stack fuel cell systems are better than single-stack systems in terms of efficiency, reliability, durability and maintenance. In this research, we developed a residential fuel cell stack and system model that generates electricity using the fuel cell-photovoltaic hybrid system. The efficiency and hydrogen consumption of the fuel cell system were calculated according to the three proposed power distribution methods (equivalent, Daisy-chain, and optimal method). As a result, the optimal power distribution method increases the efficiency of the fuel cell system and reduces hydrogen consumption. The more frequently the multi-stack fuel cell system is exposed to lower power levels, the greater the effectiveness of the optimal power distribution method.

Development of the Hydrogen Recirculation System for Fuel Cell Hybrid Vehicle (연료전지 하이브리드 자동차의 고효율 수소 재순환 시스템의 개발)

  • Kim, Min-Jin;Sohn, Young-Jun;Kim, Kyoung-Youn;Lee, Won-Yong
    • Journal of Hydrogen and New Energy
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    • v.19 no.2
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    • pp.118-123
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    • 2008
  • For the hydrogen recirculation system of the PEMFC (polymer electrolyte membrane fuel cell), the ejector is useful to improve the efficiency of the fuel cell system. However, conventional ejector does not keep its entrainment ratio good when the various power duties is required by the fuel cell system. In this study, the variable multi-ejector acceptable in the whole duty range required from the fuel cell hybrid mini-bus is developed. Consequently, the performance of the developed ejector is verified by the experiments based on the real operating conditions.

Power System of Fuel Cell Tram (연료전지궤도차량의 동력시스템)

  • Chang, Seky;Mok, Jai-Kyun;Lim, Tae-Hoon
    • Proceedings of the KSR Conference
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    • 2005.05a
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    • pp.320-325
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    • 2005
  • Power of fuel cell tram is supplied by only fuel cell system or hybrid system of fuel cell and battery/super capacity. Fuel cell is operated by hydrogen, which is fed directly from hydrogen tank or by reforming gasoline or methanol into hydrogen. Power system is preferred with hybrid of fuel cell and battery/super capacity since it improves total energy efficiency through interaction of hybrid components and restores energy regenerated by braking. Also, power supply system by fuel cell hybrid should be designed to output optimum energy efficiency depending on driving mode of fuel cell tram.

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Development of Bifunctional Electrocatalyst for PEM URFC (고분자 전해질 막을 이용한 일체형 재생 연료전지용 촉매전극 개발)

  • Yim, Sung-Dae;Park, Gu-Gon;Sohn, Young-Jun;Yang, Tae-Hyun;Yoon, Young-Gi;Lee, Won-Yong;Kim, Chang-Soo
    • Journal of Hydrogen and New Energy
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    • v.15 no.1
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    • pp.23-31
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    • 2004
  • For the fabrication of high efficient bifunctional electrocatalyst of oxygen electrode for PEM URFC (Polymer Electrolyte Membrane Unitized Regenerative Fuel Cell), which is a promising energy storage and conversion system using hydrogen as the energy medium, several bifunctional electrocatalysts were prepared and tested in a single cell URFC system. The catalysts for oxygen electrode revealed fuel cell performance in the order of Pt black > PtIr > PtRuOx > PtRu ~ PtRuIr > PtIrOx, whereas water electrolysis performance in the order of PtIr ~ PtIrOx > PtRu > PtRuIr > PtRuOx ~ Pt black. Considering both reaction modes PtIr was the most effective elctrocatalyst for oxygen electrode of present PEM URFC system. In addition, the water electrolysis performance was significantly improved when Ir or IrOx was added to Pt black just 1 wt.% without the decrease of fuel cell performance. Based on the catalyst screening and the optimization of catalyst composition and loading, the optimum catalyst electrodes for PEM URFC were $1.0mg/cm^2$ of Pt black as hydrogen electrode and $2.0mg/cm^2$ of PtIr (99:1) as oxygen electrode.

Study on Development of the Isolation Resistance Measurement System for Hydrogen Fuel Cell Vehicle (수소연료전지자동차용 절연저항 측정시스템 개발에 관한 연구)

  • Lee, Ki-Yeon;Kim, Dong-Ook;Moon, Hyun-Wook;Kim, Hyang-Kon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.5
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    • pp.1068-1072
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    • 2011
  • Hydrogen Fuel Cell Vehicle(HFCV) is system that uses electrical energy of fuel cell stack to main power source, which is different system with other vehicles that use high-voltage, large-current. Isolation performance of this system which is connected with electrical fire and electrical shock is important point. Isolation resistance of electric installation is divided according to working voltage, it follows criterion more than $100{\Omega}$/VDC (or $500{\Omega}$/VAC) about system operation voltage in a hydrogen fuel cell vehicle. Although measurement of isolation resistance in a hydrogen fuel cell vehicle is two methods, it uses mainly measurement by megger. However, the present isolation resistance measurement system that is optimized to use in electrical facilities is unsuitable for isolation performance estimation of a hydrogen fuel cell vehicle because of limit of maximum short current and difference of measurement resolution. Therefore, this research developed the isolation resistance measurement system so that may be suitable in isolation performance estimation of a hydrogen fuel cell vehicle, verified isolation performance about known resistance by performance verification of laboratory level about developed system, and executed performance verification through comparing results of developed system by performance verification of vehicle level with ones of existing megger. Developed system is judged to aid estimation and upgrade of isolation performance in a hydrogen fuel cell vehicle hereafter.

The Energy and Environmental Performance of Hydrogen Fuel Cell System in Apartment Complex (공동주택 단지 적용 수소연료전지 시스템의 에너지 및 환경 성능 평가)

  • Kim, Yong-Hee;Kim, Hae-Jung;Ko, Myeong-Jin;Kim, Yong-Shik
    • 한국태양에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.199-204
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    • 2009
  • This study analyzed the central heating system and the cogeneration system among the methods of supplying energy which have application to the Hydrogen Fuel Cell system and apartment complexes for performance evaluations. Therefore, a feasibility study on the first application of this system in an apartment complexes was considered to evaluate the energy performance by the amount of fuel consumed by the system using Hydrogen Fuel Cell energy and environmental performance by the amount of greenhouse gas emissions. As a result, the Hydrogen Fuel Cell system consumes 83% of fuel while the cogeneration system consumes 81% of fuel comparison to conventional central heating system. The Hydrogen Fuel Cell and the cogeneration system produce 73%t and 70% of greenhouse gas emissions in comparison to conventional central heating system.

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A experimental study on the sensor response at hydrogen leakage in a residential fuel cell system (가정용 연료전지 시스템 내부 수소 누출 시 센서 응답 특성에 관한 연구)

  • Kim, Young-Doo;Chung, Tae-Yong;Shin, Dong-Hoon;Nam, Jin-Hyun;Kim, Young-Gyu
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.2009-2014
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    • 2007
  • Hydrogen is a fuel of fuel cell system, which has powerful explosion possibility. Hence, the fuel cell system needs safety evaluation to prevent risk of hydrogen leakage. We use a actual size chamber of a common fuel cell module to analyze hydrogen. Hydrogen injection holes are located in lower part of the chamber in order to simulated hydrogen leakage. The hydrogen sensor can detect range of 0${\sim}$4%. Since the hydrogen gas, of which leaked amount is controled by MFC, are injected at the bottom holes, the transient sensor signals are measured. At a condition of 10cc/s of hydrogen leakage, the sensor detects hydrogen leakage after 22sec and there is also several seconds of time delay depending on the position of the sensor. This experimental data can be applied for the design of the hydrogen detection system and ventilation system of a residential fuel cell system.

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A Study on Performance Characteristics of PEMFC with Thermal Variation (온도에 따른 고분자 전해질형 연료전지시스템의 출력 특성 연구)

  • Park, Se-Joon;Shin, Young-Sik;Jeong, Seong-Chan;Choi, Jeong-Sik;Cha, In-Su
    • Proceedings of the KIEE Conference
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    • 2009.04b
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    • pp.212-214
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    • 2009
  • The polymer electrolyte membrane fuel cell(PEMFC) with the advantages of low-operating temperature, high current density, low cost and volume, fast start-up ability, and suitability for discontinuous operation becomes the most reasonable and attractive power system for transportation vehicle and micro-grid power plant in a household. 200W PEMFC(Polymer electrolyte membrane fuel cell) system applied to middle and small-scaled micro-grid power system was constructed by this study, then the electrical characteristics and diagnosis of the fuel cell were analyzed with thermal variation.

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