• 제목, 요약, 키워드: Reformer

검색결과 260건 처리시간 0.126초

마이크로 리포머의 열 및 역학적 거동 분석 (A Study on Thermal and Mechanical Behaviors of Micro Reformer)

  • 황원재;장재혁;길재형;김상진;이로운;김성한;정기호;오용수
    • 한국정밀공학회:학술대회논문집
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    • pp.235-239
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    • 2005
  • We analyzed the thermal and mechanical behaviors of micro reformer for the purpose of design verifications and modification of micro channels. The reformer designed for hydrogen generation from methanol is essential to PEM(Proton Exchange Membrane) type fuel cell. For the mobile applications, the size and the simplicity would be the most critical issues. We utilized silicon process for micro reformer to obtain the thickness thinner than 2 mm thick. We have used commercial simulation software, IDEAS, to analyze the thermal and mechanical characteristics of micro reformer structure. The heat generation rates of heaters, heat transfer rates, and fluid temperatures are derived from thermal equilibrium relation and these values were used for thermal boundary conditions. We also analyzed the thermal stresses, thermal deformations to examine the possibility of failure.

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Six-sigma 기법을 이용한 연료전지시스템 연료저리장치 최적화 (Optimization of Fuel Processing Unit of Fuel Cell System using Six-Sigma Technique)

  • 정경용;김선회
    • 디지털융복합연구
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    • v.10 no.2
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    • pp.225-229
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    • 2012
  • 소형발전용 연료전지 시스템에 있어 개질장치는 탄화수소계의 연료를 수소가 풍부한 가스로 개질하여 주는 장치이다. 개질장치는 시스템 전체의 안정성과 성능의 관점에서 중요한 핵심 지표를 가지게 되는데 개질기의 핵심평가지표 중 가장 중요한 것은 배출가스 중의 CO농도이다. 시스템의 효율, 성능 및 안정성을 위하여 CO농도를 5ppm 이하로 관리되어야 한다. 본 연구에서는 개질기의 배출가스 내의 CO농도에 영향을 미치는 핵심인자를 도출한다. 개질기의 운전 및 설계에 있어 six-sigma 기법 중의 실험계획법을 도입하여 CO 농도에 영향을 미치는 핵심인자들을 도출해내고 도출된 인자들의 개선을 통하여 최적화된 운전조건을 제시하였다. 연료전지용 개질기에 있어서 가장 중요한 CO의 농도를 제어하기 위하여 도출된 인자들은 MTS, LTS, Prox와 같은 각 개질기내의 온도제어 및 그에 관한 결과로서의 CO 농도에 대한 최적 운전조건을 도출하였다.

고체산화물 연료전지용 연료.물 직접 분무식 촉매 개질기에 관한 실험적 연구 (An Experimental Study on Catalytic Reformer with Direct Spraying of Fuel and Water for SOFC)

  • 이대근;동상근;양제복;김학주;정헌
    • 한국연소학회:학술대회논문집
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    • pp.260-265
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    • 2006
  • An experimental study on the catalytic reformer adopted in the auxiliary power unit system of solid oxide fuel cell was conducted. A 3-fluid nozzle, by which liquid fuel such as diesel, water and air are sprayed and uniformed mixed, was designed and used in this study. An electrically heated monolith inserted in the reformer was used for the vaporization of fuel and water in the transient state of reformer. The reformer uses the partial oxidizing reaction at the catalyst and the supply of water prevents the flame combustion in the spraying zone and lessens the deactivation of catalyst. The result showed that the reforming of liquid fuel can be started by the electrically heated monolith and the 3-fluid nozzle can give the uniform mixing of fuel, water and air. It was also found that the reformer fueled by n-hexadecane can make the reformate, at best, containing $H_2$ at 15.5% and CO at 11.5% that are used as fuel in the solid oxide fuel cell.

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25kW급 평판형 메탄-수증기 개질기 열유동 전산해석 (Computational Fluid Dynamics Analysis of 25kW Plate Type Methane-steam Reformer)

  • 신동훈;서혜경;임희천;이상득
    • 한국신재생에너지학회:학술대회논문집
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    • pp.103-106
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    • 2006
  • The Plate reformer consisting of combustion chamber and reforming chamber for 25 kW MCFC stack has been operated and computational fluid dynamics was applied to estimate reactions and thermal fluid behavior in the reformer. The methane air 2-stage reaction was assumed in the combustion chamber, and three step steam reforming reactions were included in the calculation. Flow uniformity, reaction rate and species distribution, and temperature distribution were analyzed. In particular, temperature distribution was compared with the measurements to show good agreement in the combustion chamber, however, inappropriate agreement in the reformer chamber

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천연가스 개질기와 연계한 연료전지시스템의 운전특성 (Operating Characteristics on Coupling of Fuel-Cell System with Natural Gas Reformer)

  • 박세준;최용성;황종선;이경섭
    • 전기학회논문지P
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    • v.58 no.4
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    • pp.639-643
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    • 2009
  • A reformer, which produces hydrogen from natural gas, plays a major role for producing quality hydrogen to fuel-cell system. In this paper, fuel processor is designed to deliver hydrogen(75%) from the reformer to 200W fuel-cell system, and the electrical output power of the fuel-cells is examined by being injected different hydrogen concentrations to the system. We verified that the output power characteristics of the fuel-cells with 75% reformed hydrogen was lower about 7% than the case of pure hydrogen supplied. The type of reformer in this experiment takes SMR(Steam methane reforming) process, and the temperature variation characteristics of reforming process by reactions are examined in operation.

천연가스를 이용한 자열개질기의 운영조건에 대한 수치해석 연구 (Numerical Study on operating conditions of Autothermal Reformer using natural gas)

  • 김진욱;김상우;박달영;전상희;이도형
    • 한국신재생에너지학회:학술대회논문집
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    • pp.91.1-91.1
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    • 2010
  • The Reforming system is an effective method to generate hydrogen which uses for fuel cell system. The purpose of this study is to present characteristics of an autothermal reformer at various operating conditions and to investigate ideal conditions for reforming efficiency. Dominant chemical reactions are Full Combustion, Steam Reforming reaction, Water-Gas Shift reaction and Direct Steam Reforming reaction. Operating parameters of the autothermal reformer are inlet temperature, Oxygen to Carbon Ratio, Steam to Carbon Ratio and Gas Hourly Space Velocity. Autothermal reformer is filled with catalysis of a packbed-bed type. Using numerical approach, we have investigated on various reaction conditions.

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연소 변수가 수증기-메탄 개질기의 특성에 미치는 영향 (The Effects of Combustion Parameters on the Characteristics of a Steam-Methane Reformer)

  • 이재성;김호영
    • 한국연소학회:학술대회논문집
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    • pp.29-31
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    • 2012
  • The effects of combustion parameters on the characteristics of a steam-methane reformer. The reformer system was numerically simulated using a simplified two-dimensional axisymmetric model domain with an appropriate user-defined function. The fuel ratio, defined as the ratio of methane flow rate in the combustor to that in the reactor, was varied from 20 to 80%. The equivalence ratio was changed from 0.5 to 1.0. The results indicated that as the fuel ratio increased, the production rates of hydrogen and carbon monoxide increased, although their rates of increase diminished. In fact, at the highest heat supply rates, hydrogen production was actually slightly decreased. Simulations showed that equivalence ratio of 0.7 yielded the highest steam-methane mixture temperature despite a 43% higher air flow rate than the stoichiometric flow rate. This means that the production of hydrogen and carbon monoxide can be increased by adjusting the equivalence ratio, especially when the heat supply is insufficient.

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수증기의 잠열을 이용한 메탄올 수증기 개질기의 특성 연구 (Study on the Characteristics of Methanol Steam Reformer Using Latent Heat of Steam)

  • 천욱래;안강섭;신현길
    • 한국수소및신에너지학회논문집
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    • v.29 no.1
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    • pp.19-24
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    • 2018
  • Fuel cells are used to generate electricity with a reformer. In particular, methanol has various advantages among the fuels for reformer. Methanol steam reformer devices can efficiently supply hydrogen to PEM fuel cell. This study investigated the optimal operation conditions of a methanol steam reforming process. For this purpose, aspen HYSYS was used for the optimization of reforming process. The optimal operating condition could be designed by setting independent variables such as temperature, pressure and steam to carbon ratio (SCR). The optimal temperature and steam to carbon ratio were $250-270^{\circ}C$ and 1.3-1.5, respectively. It is advantageous to operate at a pressure of 15-20 barg, considering the performance of the hydrogen purifier. In addition, a heat exchange network was designed to supply heat constantly to reformer through the latent heat of steam.

자열개질기의 운용조건에 따른 열유동 수치해석 (Thermal Flow Analysis of Operating Parameters in Autothermal Reformer)

  • 박승환;김진욱;박달영;김재동;이도형
    • 한국유체기계학회 논문집
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    • v.14 no.6
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    • pp.61-67
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    • 2011
  • The study is to analyze the chemical and heat-flow reactions in the hydrogen generation unit(autothermal reformer), using computational numerical tools. Autothermal reformer(ATR) is involved in complex chemical reaction, mass and heat transfer due to exothermic and endothermic reactions. Therefore it is necessary to reveal the effects of various operation parameters and geometries on the ATR performance by using numerical analysis. Numerical analysis needs to dominant chemical reactions that includes Full Combustion(FC) reaction, Steam Reforming(SR) reaction, Water-Gas Shift(WGS) reaction and Direct Steam Reforming(DSR) reaction. The objective of the study is to improve theoretically the reformer design capability for the goal of high hydrogen production in the autothermal reformer using methane. Hydrogen production reached maximum in a certain value of Oxygen to Carbon Ratio(OCR) or Steam to Carbon Ratio(SCR). When the longitudinal distance to dimeter ratio(L/D) is increased, hydrogen production increases.

초소형 2단 연소기를 이용한 리포머 시스템에 관한 연구 (Studies on a Micro Reformer System with a Two-staged Microcombustor)

  • 김기백;이정학;권오채
    • 한국수소및신에너지학회논문집
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    • v.19 no.3
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    • pp.217-225
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    • 2008
  • A new micro reformer system consisted of a micro reformer, a microcombustor and a micro evaporator was studied experimentally and computationally. In order to satisfy the primary requirements for designing the microcombustor integrated with a micro evaporator, i.e. stable burning in a small confinement and maximum heat transfer through a wall, the present microcombustor is simply cylindrical to be easily fabricated but two-staged (expanding downstream) to feasibly control ignition and stable burning. Results show that the aspect ratio and wall thickness of the microcombustor substantially affect ignition and thermal characteristics. For the optimized design conditions, a premixed microflame was easily ignited in the expanded second stage combustor, moved into the smaller first stage combustor, and finally stabilized therein. A micro reformer system integrated with a modified microcombustor based on the optimized design condition was fabricated. For a typical operating condition, the designed micro reformer system produced 22.3 sccm hydrogen (3.61 W in LHV) in an overall efficiency of 12%.