The operating temperature of a solid oxide fuel cell (SOFC) stack is a very important parameter to be controlled, which impacts the performance of the SOFC due to thermal cycling. In this paper, an adaptive fuzzy cont...The operating temperature of a solid oxide fuel cell (SOFC) stack is a very important parameter to be controlled, which impacts the performance of the SOFC due to thermal cycling. In this paper, an adaptive fuzzy control method based on an affine nonlinear temperature model is developed to control the temperature of the SOFC within a specified range. Fuzzy logic systems are used to approximate nonlinear functions in the SOFC system and an adaptive technique is employed to construct the controller. Compared with the traditional fuzzy and proportion-integral-derivative (PID) control, the simulation results show that the designed adaptive fuzzy control method performed much better. So it is feasible to build an adaptive fuzzy controller for temperature control of the SOFC.展开更多
As a mixed ion-electronic conductor, doped ceria, especially rare earth doped ceria, were used as anodes or components of anodes in SOFCs. In this work, calcium doped ceria （CCO） was synthesized to be used in interm...As a mixed ion-electronic conductor, doped ceria, especially rare earth doped ceria, were used as anodes or components of anodes in SOFCs. In this work, calcium doped ceria （CCO） was synthesized to be used in intermediate-temperature SOFCs （IT-SOFCs） anodes in order to reduce the cost of anode-supported SOFCs. Electrical conductivity of 20% calcium doped ceria （20CCO） reached 0.209 S·cm^-1 in hydrogen at 850 ℃, and 0.041 S·cm^-1 in air at 800℃, which is about 0.04 S·cm^-1 lower than that of conventional samaria-doped ceria （0.079 S·cm^-1）. Electrochemical performance of Ni-20CCO cermet as anode was investigated using a fuel cell with 35μm-thick SDC electrolyte and Sm0.5Sr0.5 Co-SDC cathode. Maximum power density was 623 mW·cm^-2 under humidified （3% H2O） hydrogen at 650 ℃, inferring high catalytic activity of the Ni-20CCO anode.展开更多
Compared with conventional electric power generation systems, the solid oxide fuel cell （SOFC） has many advantages because of its unique features. High temperature SOFC has been successfully developed to its commerc...Compared with conventional electric power generation systems, the solid oxide fuel cell （SOFC） has many advantages because of its unique features. High temperature SOFC has been successfully developed to its commercial applications, but it still faces many problems which hamper large-scale commercial applications of SOFC. To reduce the cost of SOFC, intermediate temperature solid oxide fuel cell （IT-SOFC） is presently under rapid development. The status of IT-SOFC was reviewed with emphasis on discussion of their component materials. 2008 University of Science and Technology Beijing. All rights reserved.展开更多
NiO-La0.3Ce0.7O2-δ(LDC30) novel anode was investigated for IT-SOFCs(Intermediate Temperature-Solid Oxide Fuel Cells) with LaGaO3-based electrolyte. The results showed that LDC30 has a suitable chemical compatibility ...NiO-La0.3Ce0.7O2-δ(LDC30) novel anode was investigated for IT-SOFCs(Intermediate Temperature-Solid Oxide Fuel Cells) with LaGaO3-based electrolyte. The results showed that LDC30 has a suitable chemical compatibility with NiO and NiO-LDC30 has a good thermal expansion matching with LDC30 interlayer and LSGM(La0.8Sr0.2Ga0.8Mg0.2O3-δ) electrolyte, so NiO-LDC30/LDC30 was considered as a feasible and novel anode system. It was also shown that NiO content plays a key role on polarization performance and morphology of the anode. When the content of NiO was 60%(mass fraction), the polarization loss of anode was the lowest. Next we will optimize the porosity and sintering procedure to modify the microstructure and performance of the anode.展开更多
An energy production system consisting of a solar collector, biogas dry reforming reactor and solid oxide fuel cell (SOFC) was assumed to be installed in Kolkata, India. This study aims to understand the impact of cli...An energy production system consisting of a solar collector, biogas dry reforming reactor and solid oxide fuel cell (SOFC) was assumed to be installed in Kolkata, India. This study aims to understand the impact of climate conditions on the performance of solar collectors with different lengths of parabolic trough solar collector (dx) and mass flow rate of heat transfer fluid (m). In addition, this study has evaluated the amount of H2 produced by biogas dry reforming (GH2), the amount of power generated by SOFC (PSOFC) and the maximum number of possible households (N) whose electricity demand could be met by the energy system proposed, considering the performance of solar collector with the different dx and m. As a result, the optimum dx was found to be 4 m. This study revealed that the temperature of heat transfer fluid (Tfb) decreased with the increase in m. Tfb in March, April and May was higher than that in other months, while Tfb from June to December was the lowest. GH2, PSOFC and N in March, April and May were higher than those in other months, irrespective of m. The optimum m was 0.030 kg/s.展开更多
Eleven steel grades were designed to be used as metallic interconnects for Solid Oxide Fuel Cells (SOFC). Low carbon, high chromium steel with different additives of niobium, vanadium, aluminum, molybdenum, silicon, m...Eleven steel grades were designed to be used as metallic interconnects for Solid Oxide Fuel Cells (SOFC). Low carbon, high chromium steel with different additives of niobium, vanadium, aluminum, molybdenum, silicon, manganese and titanium were produced. Phase transformation temperatures;eutectoid temperature (Ac1) and temperature at which transformation of ferrite to austenite is completed during heating (Ac3) were measured by L75-76 dilatometer. The influence of the alloying elements on transformation temperatures was analyzed using MATLab. Considering the interaction between different alloying elements two equations for predicting Ac1 & Ac3 were obtained. The obtained Ac1 & Ac3 by these equations showed more compatibility than that obtained by traditional ones. In addition, the coefficients of thermal expansion of these steel grades were detected. The influences of chemical composition and temperature on the thermal expansion coefficient were analyzed;the obtained equations were verified to certain extent by using several kinds of steels. The predicted values were in good accordance with the experimental results which proof the validation of calculation model.展开更多
文摘The operating temperature of a solid oxide fuel cell (SOFC) stack is a very important parameter to be controlled, which impacts the performance of the SOFC due to thermal cycling. In this paper, an adaptive fuzzy control method based on an affine nonlinear temperature model is developed to control the temperature of the SOFC within a specified range. Fuzzy logic systems are used to approximate nonlinear functions in the SOFC system and an adaptive technique is employed to construct the controller. Compared with the traditional fuzzy and proportion-integral-derivative (PID) control, the simulation results show that the designed adaptive fuzzy control method performed much better. So it is feasible to build an adaptive fuzzy controller for temperature control of the SOFC.
基金Project supported bythe National Natural Science Foundation of China (20271047)
文摘As a mixed ion-electronic conductor, doped ceria, especially rare earth doped ceria, were used as anodes or components of anodes in SOFCs. In this work, calcium doped ceria （CCO） was synthesized to be used in intermediate-temperature SOFCs （IT-SOFCs） anodes in order to reduce the cost of anode-supported SOFCs. Electrical conductivity of 20% calcium doped ceria （20CCO） reached 0.209 S·cm^-1 in hydrogen at 850 ℃, and 0.041 S·cm^-1 in air at 800℃, which is about 0.04 S·cm^-1 lower than that of conventional samaria-doped ceria （0.079 S·cm^-1）. Electrochemical performance of Ni-20CCO cermet as anode was investigated using a fuel cell with 35μm-thick SDC electrolyte and Sm0.5Sr0.5 Co-SDC cathode. Maximum power density was 623 mW·cm^-2 under humidified （3% H2O） hydrogen at 650 ℃, inferring high catalytic activity of the Ni-20CCO anode.
基金the National Basic Research Program of China(No.2007CB936201)the National High Technology Research and Development Program of China(863 Program)(No.2006AAO3Z351)the Major International(Regional)Joint Research Program of China(No.50620120439,2006DFB51000).
文摘Compared with conventional electric power generation systems, the solid oxide fuel cell （SOFC） has many advantages because of its unique features. High temperature SOFC has been successfully developed to its commercial applications, but it still faces many problems which hamper large-scale commercial applications of SOFC. To reduce the cost of SOFC, intermediate temperature solid oxide fuel cell （IT-SOFC） is presently under rapid development. The status of IT-SOFC was reviewed with emphasis on discussion of their component materials. 2008 University of Science and Technology Beijing. All rights reserved.
文摘NiO-La0.3Ce0.7O2-δ(LDC30) novel anode was investigated for IT-SOFCs(Intermediate Temperature-Solid Oxide Fuel Cells) with LaGaO3-based electrolyte. The results showed that LDC30 has a suitable chemical compatibility with NiO and NiO-LDC30 has a good thermal expansion matching with LDC30 interlayer and LSGM(La0.8Sr0.2Ga0.8Mg0.2O3-δ) electrolyte, so NiO-LDC30/LDC30 was considered as a feasible and novel anode system. It was also shown that NiO content plays a key role on polarization performance and morphology of the anode. When the content of NiO was 60%(mass fraction), the polarization loss of anode was the lowest. Next we will optimize the porosity and sintering procedure to modify the microstructure and performance of the anode.
文摘An energy production system consisting of a solar collector, biogas dry reforming reactor and solid oxide fuel cell (SOFC) was assumed to be installed in Kolkata, India. This study aims to understand the impact of climate conditions on the performance of solar collectors with different lengths of parabolic trough solar collector (dx) and mass flow rate of heat transfer fluid (m). In addition, this study has evaluated the amount of H2 produced by biogas dry reforming (GH2), the amount of power generated by SOFC (PSOFC) and the maximum number of possible households (N) whose electricity demand could be met by the energy system proposed, considering the performance of solar collector with the different dx and m. As a result, the optimum dx was found to be 4 m. This study revealed that the temperature of heat transfer fluid (Tfb) decreased with the increase in m. Tfb in March, April and May was higher than that in other months, while Tfb from June to December was the lowest. GH2, PSOFC and N in March, April and May were higher than those in other months, irrespective of m. The optimum m was 0.030 kg/s.
文摘Eleven steel grades were designed to be used as metallic interconnects for Solid Oxide Fuel Cells (SOFC). Low carbon, high chromium steel with different additives of niobium, vanadium, aluminum, molybdenum, silicon, manganese and titanium were produced. Phase transformation temperatures;eutectoid temperature (Ac1) and temperature at which transformation of ferrite to austenite is completed during heating (Ac3) were measured by L75-76 dilatometer. The influence of the alloying elements on transformation temperatures was analyzed using MATLab. Considering the interaction between different alloying elements two equations for predicting Ac1 & Ac3 were obtained. The obtained Ac1 & Ac3 by these equations showed more compatibility than that obtained by traditional ones. In addition, the coefficients of thermal expansion of these steel grades were detected. The influences of chemical composition and temperature on the thermal expansion coefficient were analyzed;the obtained equations were verified to certain extent by using several kinds of steels. The predicted values were in good accordance with the experimental results which proof the validation of calculation model.
