• Title/Summary/Keyword: 고체산화물전지

Search Result 469, Processing Time 0.029 seconds

Long Term Operation and Improvement Reliability for SOFC System (SOFC 시스템의 장시간 운전 및 시스템 신뢰성 향상)

  • YI, YONG;SHIN, SEOCK JAE;PARK, SE JIN;KIM, MIN SOO;KIM, HYUNG JOONG;KIM, JUN HO;KIM, INHWAN;KIM, YONG SU
    • Journal of Hydrogen and New Energy
    • /
    • v.28 no.5
    • /
    • pp.502-511
    • /
    • 2017
  • Design, manufacture and operate the 700W Solid oxide fuel cell system suitable for housing. Except for BOP not produced domestically, most of the domestic BOPs were applied as much as possible. Finally, the system size was 350 liter. System performance was electric efficiency 44.64%, thermal efficiency 40.99%, total efficiency 85.62% at certificate authority. The system was operated for 4,500 hours, this operation time include automatically system on/off, E-stop for emergency stop, load trip for blackout and inverter error. There were that the system on/off were 26 times. System performance remains intact after system on/off.

Operation Results of the SOFC System Using 2 Sub-Module Stacks (2 모듈 스택을 이용한 SOFC 시스템 운전결과)

  • Lee, Tae-Hee
    • Journal of Hydrogen and New Energy
    • /
    • v.21 no.5
    • /
    • pp.405-411
    • /
    • 2010
  • A 5kW class SOFC cogeneration system consisted of a hot box part, a cold BOP (balance of plant) part, and a hot water reservoir. The hot box part contained a stack, a fuel reformer, a catalytic combustor, and heat exchangers. A cold BOP part was composed of blowers, pumps, a water trap, and system control units. A 5kW stack was designed to integrate 2 sub-modules. In this paper, the 5kW class SOFC system was operated using 2 short stacks connected in parallel to test the sub-module and the system. A short stack had 15 cells with $15{\times}15 cm^2$ area. When a natural gas was used, the total power was about 1.38 kW at 120A. Because the sub-modules were connected in parallel and current was loaded using a DC load, voltages of sub-modules were same and the currents were distributed according to the resistance of sub-modules. The voltage of the first stack was 11.46 V at 61A and the voltage of the second stack was 11.49V at 59A.

An Experimental Study on the Performances of a Coupled Reactor with Catalytic Combustion and Steam Reforming for SOFC and MCFC (SOFC와 MCFC에 적용하기 위한 촉매연소-수증기 개질이 통합된 반응기의 성능에 관한 실험적 연구)

  • Ghang, Taegyu;Kim, Yongmo;Lee, Sangmin;Ahn, Kookyoung
    • Journal of Hydrogen and New Energy
    • /
    • v.25 no.4
    • /
    • pp.364-377
    • /
    • 2014
  • The performances of a coupled reactor in which a steam reformer and a catalytic combustor were mounted simultaneously had been investigated and compared. The combustible offgas exhausted from the anode of SOFC and MCFC were utilized as heat sources for the endothermic steam methane reforming. The catalytic combustion was used in order to burn the combustible offgas. Thermal energy released by the catalytic combustion is directly transferred to the reformer surrounding the combustor. The various operational conditions such as fuel utilization rate, steam to carbon ratio, amount of catalysts, fuel cell loads were changed. And operating variables were comprehensively identified by sensitivity analysis. The fundamental results from this experimental study show the potential abilities of the coupled reactor. Therefore the results will be of help to design and manufacture the more better coupled reactor in the future.

A Study on the Efficiency of Fuel Cells for Marine Generators (선박 발전기용 연료전지 시스템의 효율에 관한 연구)

  • Lee, Jung-Hee;Kwak, Jae-Seob;Kim, Kwang-Heui
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.17 no.5
    • /
    • pp.52-57
    • /
    • 2018
  • Most current ships have adopted on-board diesel generators to produce electricity, but the overall efficiency of equipment is down to about 50% due to thermal losses from operations such as exhaust gas, jacket water cooler, scavenge air cooler, etc. Recently, fuel cells have been highlighted as a promising technology to reduce the effect on the environment and have a higher efficiency. Therefore, this paper suggested a solid oxide fuel cell (SOFC)-gas turbine (GT) using waste heat from a SOFC and SOFC-GT-steam turbine (ST) with Rankine cycle. To compare both configurations, the fuel flow rate, current density, cell voltage, electrical power, and overall efficiency were evaluated at different operating loads. The overall efficiency of both SOFC hybrid systems was higher than the conventional system.

Improvement of Oxidation-resisting Characteristic for SOFC Interconnect Material by Use of Thin Film Coating (박막 코팅을 이용한 SOFC 분리판 재료의 내산화성 향상)

  • Lee, Chang-Bo;Bae, Joong-Myeon
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.30 no.12 s.255
    • /
    • pp.1211-1217
    • /
    • 2006
  • This study is focused on oxidation prevention of STS430, which is generally used as solid oxide fuel cell(SOFC) interconnect at intermediate operating temperatures with oxidation-proof coatings. Inconel, $La_{0.6}Sr_{0.4}CoO_3(LSCo)$ and $La_{0.6}Sr_{0.4}CoO_3(LSCr)$ were chosen as coating materials. Using a radio frequency magnetron sputtering method, each target material was deposited as thin film on STS430 and was analyzed to find out favorable conditions. In this study, LSCr-coated STS430 can reduce electrical resistance to 1/3 level, compared with uncoated STS430. Also, long-term durability test at $700^{\circ}C$ for 1000 hours tells that LSCr thin layer performs an important role to prohibit serious degradations. Superior oxidation-resistant characteristic of LSCr-coated STS430 is attributed to the inhibition of spinel structure formation such as $MnCr_2O_4$.

Effect of Oxidation of Ni on the Microstructure of Ni/YSZ Anode and Crack Formation in YSZ Electrolyte Layer for SOFC (Ni의 산화가 고체산화물 연료전지용 Ni/YSZ 연료극의 미세조직과 전해질의 균열에 미치는 영향)

  • Lim, Jun-Sil;Choi, Jong-Joon;Kwon, Oh-Jong
    • Journal of the Korean Ceramic Society
    • /
    • v.43 no.12 s.295
    • /
    • pp.805-811
    • /
    • 2006
  • The microstructural changes in Ni/YSZ anode substrate and crack formation during Ni oxidation were investigated. The composition of as-sintered anodes was 56 wt% NiO+44 wt% YSZ and that of electrolyte was 8 mol% yttria. After complete reduction, specimens were oxidized in $N_2$ + air at $600\sim800^{\circ}C$. Oxygen partial pressure was controlled in between 0.05 atm and 0.2 atm $O_2$. When the anode was oxidized, at higher than $690^{\circ}C$, three layers were formed in the specimens. The first was fully oxidized layer(NiO/YSZ), the second was a mixed layer and the third, near-intact layer. Under $640^{\circ}C$ such distinctive layers were not observed. Cracks formed at electrolyte layer when weight gain attained at $65\sim75%$ of the total gain due to complete oxidation despite of different oxidation temperature and oxygen partial pressure.

Characterization of $SiO_2-R_2O_3$-RO with compositions changes of $R_2O_3$, RO on Sealant ($SiO_2-R_2O_3$-RO계에서 $R_2O_3$, RO 변화에 따른 밀봉재 특성)

  • Yang, Sang-Jin;Choi, Byung-Hyun;Lee, Mi-Jai;Lee, Hong-Lim;Yoo, Young-Sung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2007.11a
    • /
    • pp.23-23
    • /
    • 2007
  • 고체산화물연료전지(SOFC)는 연료가 갖는 화학에너지를 연소과정 없이, 공기와 $H_2$, CO, $CH_4$와 같은 환원성 가스를 공급받아 $700^{\circ}C-850^{\circ}C$에서 전기화학적 반응을 통하여 직접 전기를 얻는 방식이다. SOFC는 여러장의 단위 셀을 적층하여 스택을 구성하는데, 스택 제조시 단전지에 공급되는 산화, 환원 가스의 누출이나 흡입을 막기 위하여 밀봉재를 사용한다. 이러한 밀봉재는 완벽한 밀봉, 열에 대한 안정성, 충격에 견디는 저항성 등의 기계적인 특성 및 구성요소와의 최소한의 열팽창계수차를 가져야 한다. 따라서 본 연구에서는 $SiO_2-R_2O_3$-RO계에서 $R_2O_3$, RO의 변화에 따른 밀봉 특성 및 열팽창계수에 미치는 영향을 조사하였다.

  • PDF

Fabrication of 8YSZ-$Al_2O_3$ solid oxide full cell (SOFC) electrolyte by a spark plasma sintering method (방전 플라즈마 소결법을 이용한 8YSZ-$Al_2O_3$ 고체 산화물 연료전지 전해질 제조)

  • Kim Jae Kwang;Choi Bong Geun;Yang Jae Kyo;Choa Yong Ho;Shim Kwang Bo
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.15 no.1
    • /
    • pp.16-20
    • /
    • 2005
  • In order to improve electrical conductivity and mechanical properties of 8YSZ SOFC electrolyte material, we used Al₂O₃ as an additive and applied the spark plasma sintering (SPS) method. The sintered bodies were densified above 96 % of theoretical density at 1200℃ and possessed microstructures composed of homogeneous grains less than 1 ㎛ in size. The addition of Al₂O₃ improved fracture toughness and bending strength by inhibiting grain growth of 8YSZ and increased total ionic conductivity because grain interior conductivity appeared to remain constant and grain boundary conductivity increased. It was assumed that the dissolution of Al₂O₃ into 8YSZ which was inevitable problem at commercial sintering method was effectively prohibited by the SPS technique with a relatively low sintering temperature and the reaction between Al₂O₃ and SiO₂ present at grain boundary to produce the crystalline Al/sub 2-x/Si/sub l-y/O/sub 5/ phase, resulting in the increase of grain boundary conductivity.

Study on Internal Reforming Characteristic of 1 kW Solid Oxide Fuel Cell Stack (1 kW 고체산화물 연료전지 스택의 내부개질 특성 연구)

  • CHOI, YOUNGJAE;AHN, JINSOO;LEE, INSUNG;BAE, HONGYOUL;MOON, JIWOONG;LEE, JONGGYU
    • Journal of Hydrogen and New Energy
    • /
    • v.28 no.4
    • /
    • pp.377-383
    • /
    • 2017
  • This paper presents the performance characteristics of a 1 kW solid oxide fuel cell (SOFC) stack under various internal reforming and fuel utilization conditions. The Research Institute of Industrial Science & Technology (RIST) developed the 9-cell stack using a $20{\times}20cm^2$ anode supported planar cell with an active area of $324cm^2$. In this work, current-voltage characteristic test, fuel utilization test, continuous operation, and internal reforming test were carried out sequentially for 765 hours at a furnace temperature of $700^{\circ}C$. The influence of fuel utilization and internal reforming on the stack performance was analyzed. When the 1 kW stack was tested at a current of 145.8 A with a corresponding fuel utilization of 50-70% (internal reforming of 50%) and air utilization of 27%, the stack power was approximately 1.062-1.079 kW. Under continuous operation conditions, performance degradation rate was 2.16%/kh for 664 hours. The internal reforming characteristics of the stack were measured at a current of 145.8. A with a corresponding fuel utilization of 60-75%(internal reforming of 50-80%) and air utilization of 27%. As fuel utilization and internal reforming ratio increased, the stack power was decreased. The stack power change due to the internal reforming ratio difference was decreased with increasing fuel utilization.

A Case Study of Different Configurations for the Performance Analysis of Solid Oxide Fuel Cells with External Reformers (외부 개질형 평판형 고체 산화물 연료전지 시스템 구성법에 따른 효율특성)

  • Lee, Kang-Hun;Woo, Hyun-Tak;Lee, Sang-Min;Lee, Young-Duk;Kang, Sang-Gyu;Ahn, Kook-Young;Yu, Sang-Seok
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.36 no.3
    • /
    • pp.343-350
    • /
    • 2012
  • A planar solid oxide fuel cell (PSOFC) is studied in its application in a high-temperature stationary power plant. Even though PSOFCs with external reformers are designed for application from the distributed power source to the central power plant, such PSOFCs may sacrifice more system efficiency than internally reformed SOFCs. In this study, modeling of the PSOFC with an external reformer was developed to analyze the feasibility of thermal energy utilization for the external reformer. The PSOFC system model includes the stack, reformer, burner, heat exchanger, blower, pump, PID controller, 3-way valve, reactor, mixer, and steam separator. The model was developed under the Matlab/Simulink environment with Thermolib$^{(R)}$ modules. The model was used to study the system performance according to its configuration. Three configurations of the SOFC system were selected for the comparison of the system performance. The system configuration considered the cathode recirculation, thermal sources for the external reformer, heat-up of operating gases, and condensate anode off-gas for the enhancement of the fuel concentration. The simulation results show that the magnitude of the electric efficiency of the PSOFC system for Case 2 is 12.13% higher than that for Case 1 (reference case), and the thermal efficiency of the PSOFC system for Case 3 is 76.12%, which is the highest of all the cases investigated.