• Title, Summary, Keyword: Reformer

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A Study on the Evaporator Shape for the Heat Transfer Performance of Fuel Cell Reformer (연료전지 개질기용 증발기 열교환 성능을 위한 증발기 형상에 관한 연구)

  • Suh, Ho-Cheol;Kim, Kyu-Jun;Noh, Hyung-Chul;Park, Kyoung-Suk
    • Journal of the Korean Society for Precision Engineering
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    • v.28 no.1
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    • pp.108-114
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    • 2011
  • Steam reformer was organized with steam reforming process and CO removing process. The steam reforming process needed high temperature, 600~900 $^{\circ}C$, for catalytic-reaction which was extract of hydrogen from steam and hydrocarbon. The effects of the evaporator configuration on its heat transfer characteristics were investigated both experimentally and numerically to pursue the miniaturization. In this study, three configurations were considered where the different structures were tested; empty, embossing and mesh filled. For the comparison of heat transfer performance of shape evaporator disk, numerical analysis using SC-Tetra code and experiment were carried out. In case of reformer system design, it should be considered heat transfer rate, differential pressure and fluid flow direction.

Investigation of the coaxial cylindrical steam reformer for fuel cell applications (연료전지 적용을 위한 동축원통형 수증기 개질기의 연구)

  • Park, Joon-Geun;Lee, Shin-Ku;Bae, Joong-Myeon;Kime, Myoung-Jun
    • 한국신재생에너지학회:학술대회논문집
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    • pp.113-116
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    • 2007
  • Performance of a steam reformer can be improved by using a coaxial cylindrical reactor, because the design can enhance the heat transfer for the steam reforming reaction, which is the one of main rate-determining steps of overall reactions. The objective of this study is to investigate the coaxial cylindrical reactor numerically. Pseudo-homogeneous model and one medium approach are incorporated for the chemical reactions, and models are validated with experimental results. The catalyst of the coaxial cylindrical reactor is 67% for one of the cylindrical reactor, but fuel conversion of the coaxial cylindrical reactor is increased by 10%. Heat flux profiles are investigated by modified Nusselt number and heat flux which is transported from the product gas to the catalyst bed affecting performance of the steam reformer.

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Plasma Reformer for Low NOx Combustion (저 NOx 연소를 위한 플라즈마 개질기)

  • Kim, Kwan-Tae;Lee, Dae-Hoon;Cha, Min-Suk;Keel, Sang-In;Yoon, Jin-Han;Song, Young-Hoon
    • 한국연소학회:학술대회논문집
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    • pp.187-190
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    • 2007
  • A combined hydrogen generator of plasma and catalytic reformers has been developed, and has been applied to stabilize unstable flame of 200,000 Kcal/hr LPG combustor. The role of the plasma reformer is to generate hydrogen in a short period and to heat-up the catalytic reformer during the start-up time. After the start-up period, the catalytic reformer generates hydrogen through steam reforming with oxygen (SRO) reactions. The maximum capacity of the hydrogen generator is 100 lpm that is sufficient to be used to stabilize the flame of the present combustor. In order to reduce NOx and CO emissions simultaneously, 1) FGR (Flue Gas Recirculation) technique has been adopted and 2) the hydrogen has been added into the fuel supplied to the combustor. Test results shows that 25 % addition of hydrogen and 30 % FGR rate lead to simultaneous decrease of CO and NOx emissions. The technique proposed in the present study shows good potential to replace $NH_3$ SCR technique, especially in the case of small-scale combustor applications.

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Examination of 2-Fluid Nozzle and 3-Fluid Nozzle for Fuel Reformer of 5 kW SOFC System (5 kW급 SOFC 시스템의 연료 개질기를 위한 2-유체 노즐과 3-유체 노즐의 검토)

  • Kwon, Hwa-Kil;Lee, Chi-Young;Lee, Sang-Yong
    • Journal of ILASS-Korea
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    • v.13 no.1
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    • pp.16-21
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    • 2008
  • In the present study, the 2-fluid nozzle and 3-fluid nozzle to atomize the diesel and water with air for the fuel reformer of SOFC system were experimentally examined. In the 2-fluid nozzle, the diesel and water were alternately atomized due to bislug flow pattern, and it implies that the mixing of both liquids strongly affects the atomization pattern. On the other hand, in the 3-fluid nozzle, the diesel and water were atomized simultaneously due to the separated injection channels without mixing problem. Therefore, compared to the 2-fluid nozzle, the 3-fluid nozzle is suitable for the stable operation of the fuel reformer. In case of the 3-fluid nozzle, Type A where the air was supplied through the central channel was the most efficient.

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Planar fuel cell design integrated with methanol reformer by using a high temperature membrane (고온형 멤브레인을 사용한 메탄올 개질 연료전지의 개질기 일체형 평판 설계)

  • Kim, Sung-Han;Jang, Jae-Hyuk;Gil, Jae-Hyoung;Lee, Hong-Ryul;Cha, Hye-Yeon;Ku, Bo-Sung;Jung, Chang-Ryul;Kundu, Arunaha;Miesse, Craig;Oh, Yong-Soo
    • 한국신재생에너지학회:학술대회논문집
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    • pp.467-470
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    • 2006
  • For a mobile application such as cellular phone, micro fuel cells should be extremely compact and thin. RHFC can be an alternative solution because RHFC gives higher power density than DMFC and does not need ahydrogen storage vessel In this paper, RHFC using methanol fuel is made as a novel planar design without a PROX. Both reformer and cell are made closely in a same plate to share the heater of reformer with the cell. The PBI membrane is used in the cell. The reason is that high temperature of reformer can cause a performance drop when perfluorosulfonic acid membrane such as Nafion is used such a high temperature operation also guarantees the higher CO tolerance to MEA catalyst. The cell is designed as an air-breathing type which the cathode of the cell is opened to the air. The commercial Cu/ZnO/Al2O3 steam reformer catalyst is packed in reformer channel. The active area of MEA is $11.9cm^2$ and the peak power density was $27.5mW/cm^2$.

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A Personal Reformer(PR) for your Fuel cell system (연료전지를 위한 개인용 개질기)

  • Kim Hyeon Yeong
    • 한국전기화학회:학술대회논문집
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    • pp.103-108
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    • 2004
  • The present paper relates to an apparatus in which all carbonaceous material such as coal, oil, plastics and any substance having carbon atoms as part of its constituents are reformed(gasified) into syngas at temperature above $1,200^{\circ}C$(KR patent No.0391121, and PCT/KR2001/01717 and PCT/KR2004/001020). It comprises a single-stage reforming reactor without catalyst and a syngas burner as shown in Fig.2. syngas is combusted with $O_2$ gas in the syngas bunter to produce $M_2O$ and $CO_2$ gas with exothermic heat. Reaction products are introduced into the reforming reactor, reaction heat from syngas burner elevate the temperature of reactor above $1,200^{\circ}C$, and reaction products reduce carbonaceous material down to CO and $H_2$ gases. Reactants and heat necessary for the reaction are provided through the syngas burner only, Neither $O_2$ gas nor steam are injected into the reforming reactor. Reformer is made of ceramic inner lining and sst outer casing. Multiple syngas burners may be connected to the reforming reactor in order to increase the syngas output, and a portion of the product syngas is recycled into syngas burner. The present reformer as shown in Fig.2 is suitable to gasify carbonaceous wastes without secondary pollutants formed from oxidation. Further, it can be miniaturized to accompany a fuel cell system as shown in Fig.3 The output syngas may be used to drive a fuel cell and a portion of electrical power generated in a fuel cell is used to heat a compact reformer up to $1,200^{\circ}C$ so that gas/liquid fossil fuel can efficiently reformed into syngas. The fuel cell serves as syngas burner in Fig.2. The reformation reaction is sustained through recycling a portion of product syngas into a fuel cell and using a portion of electric power generated to heat the reformer for continuous operation. Such reforming reactor may be miniaturized into a size of PC, then you have a Personal Reformer(PR).

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A Numerical Study on a High-Temperature Air Combustion Burner for a Compact Fuel-Cell Reformer (연료전기용 컴팩트형 개질기의 고성능화를 위한 고온 공기 연소 기술의 적용에 관한 연구)

  • Lee, Kyoung-Ho;Kwon, Oh-Chae
    • Transactions of the Korean hydrogen and new energy society
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    • v.16 no.3
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    • pp.229-237
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    • 2005
  • A new burner configuration for a compact fuel-cell reformer with a high-temperature air combustion concept was numerically studied. The burner was designed for a 40 $Nm^3/hr$ hydrogen-generated reformer using natural gas-steam reforming method. In order to satisfy the primary requirements for designing a reformer burner (uniform distribution of temperature along the fuel processor walls and minimum heat losses from the reformer), the features of the present burner configuration included 1) a self-regenerative burner for an exhaust-gas-recirculation to apply for the high-temperature air combustion concept, and 2) an annular-type shield for protecting direct contact of flame with the processor walls. For the injection velocities of the recirculated gas of 0.6-2.4 m/s, the recirculated gas temperature of 1000 K, and the recirculated oxygen mole fraction of 4%, the temperature distributions along the processor walls were found uniform within 100 K variation. Thus, the present burner configuration satisfied the requirement for reducing temperature gradients along the processor walls, and consequently demonstrated that the high-temperature air combustion concept could be applied to the practical fuel reformers for use of fuel cells. The uniformity of temperature distribution is enhanced as the amount of the recirculated gas increases.

Study on the Design Parameters of a Heat Exchange Steam Reformer (HESR) using CFD (전산유체해석을 이용한 열교환형 수증기 개질기의 디자인 파라미터 연구)

  • YANG, CHANUK;LEE, YULHO;PARK, SANGHYUN;YANG, CHOONGMO;PARK, SUNGJIN
    • Transactions of the Korean hydrogen and new energy society
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    • v.27 no.1
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    • pp.1-12
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    • 2016
  • In this study, CFD model for a Heat Exchange Steam Reformer (HESR) used for a 10kW SOFC system is developed for the design optimization of the HESR. The model is used to explore the effect of design parameters on the performance of the HESR. In the HESR, heat is delivered from the hot gas channel to the fuel channel to supply the heat required for the fuel reforming. In the fuel channel where the fuel is reformed, thermo-fluid dynamics, heat transfer, and chemical reaction are considered to predict the performance of the reformer. The model is validated with experimental data within 2~3% error. The validated model is used for the parametric study of the HESR design. Channel length, channel diameter, and flow direction are selected as the design parameters. The effects of the HESR design parameters on the outlet temperature, outlet H2 mole fraction, and pressure drop across the reformer are presented using the model.

Parametric Study of SOFC System Efficiency Under Operation Conditions of Butane Reformer (부탄 개질기 운전조건에 따른 SOFC 시스템 효율에 대한 연구)

  • Kim, Sun-Young;Baek, Seung-Whan;Bae, Gyu-Jong;Bae, Joong-Myeon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.34 no.4
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    • pp.341-347
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    • 2010
  • In this study, the efficiency of a solid-oxide fuel cell (SOFC) system with a steam reformer or prereformer was analyzed under various conditions. The main components of the system are the reformer, SOFC, and water boiling heat recovery system. Endothermic and exothermic reactions occur in the reformer and SOFC, respectively. Hence, the thermal management of the SOFC system greatly influences the SOFC system efficiency. First, the efficiencies of SOFC systems with a steam reformer and a prereformer are compared. The system with the prereformer was more efficient than the one with steam reformer due to less heat loss. Second, the system efficiencies under various prereformer operating conditions were analyzed. The system efficiency was a function of the heat requirement of the system. The efficiency increased with an increase in the operating temperature of the prereformer, and the maximum system efficiency was observed at $450^{\circ}C$ for a S/C of 2.0.

A Numerical Study on Mass Transfer and Methanol Conversion Efficiency According to Porosity and Temperature Change of Curved Channel Methanol-Steam Reformer (곡유로 메탄올-수증기 개질기 공극률 및 온도 변화에 따른 물질 전달 및 메탄올 전환율에 대한 수치해석적 연구)

  • Seong, Hong Seok;Lee, Chung Ho;Suh, Jeong Se
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.40 no.11
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    • pp.745-753
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    • 2016
  • Micro methanol-steam reformer for fuel cell can effectively produce hydrogen as reforming response to steam takes place in low temperature (less than $250^{\circ}C$). This study conducted numerical research on this reformer. First, study set wall temperature of the reformer at 100, 140, 180 and $220^{\circ}C$ while methanol conversion efficiency was set in 0, 0.072, 3.83 and 46.51% respectively. Then, porosity of catalyst was set in 0.1, 0.35, 0.6 and 0.85 and although there was no significant difference in methanol conversion efficiency, values of pressure drop were 4645.97, 59.50, 5.12 and 0.45 kPa respectively. This study verified that methanol-steam reformer rarely responds under the temperature of $180^{\circ}C$ and porosity does not have much effect on methanol conversion efficiency if the fluid flowing through reformer lowers activation energy by sufficiently contacting reformer.