• Title/Summary/Keyword: Preconverter

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NUMERICAL STUDY OF HEAT TRANSFER AND FUEL CONVERSION FOR MCFC'S PRECONVERTER (MCFC 프리컨버터 촉매의 열전도특성과 연료전환율 해석)

  • Byun, D.H.;Sohn, C.H.
    • 한국전산유체공학회:학술대회논문집
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    • 2011.05a
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    • pp.112-116
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    • 2011
  • In this paper, a preconverter of MCFC for an emergence electric power supplier is numerically simulated to increase the hydrogen production from natural gas (methane). Commercial code is used to simulated the porous catalyst with user subroutine to model three dominant chemical reactions which are Stream Reforming(SR), Water-Gas Shift(WGS), and Direct Stram Reforming(DSR). To get 10% fuel conversion rate in preconverter. the required external heat flux is supplied from outer wall of preconverter. The calculated results show that very nonuniform temperature distribution and chemical reaction happen near the wall of preconverter. These phenomena can be explained by the low heat conductivity of porous catalyst and the endothermic reforming reaction.

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Numerical Analysis of Heat Transfer and Fuel Conversion for MCFC Preconverter (MCFC 프리컨버터 촉매의 열전도특성과 연료전환율 해석)

  • Byun, Do-Hyun;Sohn, Chang-Hyun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.36 no.4
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    • pp.425-430
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    • 2012
  • In this study, a preconverter of an MCFC for an emergency electric power supplier is numerically simulated to increase the hydrogen production from natural gas (methane). A commercial code is used to simulate a porous catalyst with a user subroutine to model three dominant chemical reactions-steam reforming, water-gas shift, and direct steam reforming. To achieve a fuel conversion rate of 10% in the preconverter, the required external heat flux is supplied from the outer wall of the preconverter. The calculated results show that the temperature distribution and chemical reaction are extremely nonuniform near the wall of the preconverter. These phenomena can be explained by the low heat conductivity of the porous catalyst and the endothermic reforming reaction. The calculated results indicate that the use of a compact-size preconverter makes the chemical reaction more uniform and provides many advantages for catalyst maintenance.

Numerical Analysis of New Proposals to Enhance Heat Transfer in MCFC'S Preconverter (열전달 향상을 위한 새로운 MCFC 연료전지용 프리컨버터의 수치해석)

  • Sohn, Chang Hyun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.37 no.8
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    • pp.753-758
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    • 2013
  • In this study, two proposals for the wall heating preconverter of an MCFC are numerically studied to resolve hot temperature generation near the wall by the low thermal conductivity of the catalyst. The numerical results show that the inserted porous cupper plates on the catalyst evidently improve heat transfer and realize more uniform reforming in the preconverter. The calculated results for the preconverter with a circumference empty space of catalyst located at center, 1/2 and 4/5 from center line are compared. The circumference empty space located at 1/2 position shows better results than other cases, but the positive effect on the uniform reforming process is less than in the case of inserted cupper porous plates on the catalyst.

NUMERICAL STUDY OF STREAM REFORMING IN PRECONVERTER FOR MCFC (MCFC용 프리컨버터 수증기 개질반응의 수치연구)

  • Byun, Do-Hyun;Sohn, Chang-Hyun
    • 한국전산유체공학회:학술대회논문집
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    • 2010.05a
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    • pp.228-232
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    • 2010
  • In this paper, various operating parameters of stream reforming process from methane in preconverter for MCFC is studied by numerical method. Commercial code is used to simulated the porous catalyst with user subroutine to model three dominant chemical reactions which are Stream Reforming(SR), Water-Gas Shift(WGS), and Direct Stram Reforming(DSR). The hydrogen production is tested with different wall temperature, Gas Hourly Space Velocity(GHSV), and different reactor shapes.

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NUMERICAL STUDY OF STREAM REFORMER AND PRECONVERTER FOR MCFC (MCFC용 개질기 및 프리컨버터의 수치연구)

  • Byun, Do-Hyun;Sohn, Chang-Hyun
    • Journal of computational fluids engineering
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    • v.16 no.1
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    • pp.42-47
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    • 2011
  • In this paper, various operating parameters of stream reforming process from methane in stream reformer and preconverter for MCFC is studied by numerical method. Commercial code is used to simulated the porous catalyst with user subroutine to model three dominant chemical reactions which are Stream Reforming(SR), Water-Gas Shift(WGS), and Direct Stram Reforming(DSR). The hydrogen production is tested with different wall temperature and different reactor shapes. The calculated results of the concentration of hydrogen in stream reformer are very well consistent with experimental results. This numerical study gives the design reactor wall temperature condition and size of reactor to satisfy the required fuel conversion.