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A two-dimensional electrochemical model including mass and charge transfer has been developed to illustrate the effects of testing configurations and cell geometries on SOFC’s performance. The model is favorably validated by the well agreeable experimental results. It is shown that the separation of anode and cathode overpotential by three-electrode method is essentially impractical for anode-supported SOFCs. It is also found that testing configuration has little effect on cell performance due to the high electrical conductivity in anode. Furthermore, because the effective resistance of electrolyte is lower for asymmetric cells than for symmetric cells, cell performance of a symmetric cell is smaller than that of an asymmetric cell. Discrepancy in cell performance is shown to increase with increasing the thickness of electrolyte or decreasing the cathode radii. 相似文献
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995.
Chao JinChenghao Yang Fei ZhaoDaan Cui Fanglin Chen 《International Journal of Hydrogen Energy》2011,36(5):3340-3346
La0.75Sr0.25Cr0.5Mn0.5O3 (LSCM) has been applied as hydrogen electrode (cathode) material in solid oxide electrolysis cells operating with different steam concentrations (20, 40, 60 and 80 vol.% absolute humidity (AH)) using 40 sccm H2 carrier gas at 800, 850 and 900 °C, respectively. Impedance spectra and voltage-current curves were measured as a function of cell electrolysis current density and steam concentration to characterize the cell performance. The cell resistance decreased with the increase in electrolysis current density while increased with the increase in steam concentration under the same electrolysis current density. At 1.6 V applied electrolysis voltage, the maximum consumed current density increased from 431 mA cm−2 for 20 vol.% AH to 593 mA cm−2 for 80 vol.% AH at 850 °C. Polarization and impedance spectra experiments revealed that LSCM-YSZ hydrogen electrode played a major role in the electrolysis reaction. 相似文献
996.
新的地域并网式太阳能发电系统的电力经济分析与设计 总被引:3,自引:1,他引:3
提出一种新的地域并网式太阳能发电系统,即带有电力存储系统的地域并网式太阳能发电系统。从电力的有效利用、经济性的角度对这种新的地域并网式太阳能发电系统进行了研究,提出了系统的设计以及选定电力存储系统存储容量的方法,然后针对不同的条件选择了相应的电力存储系统的容量。 相似文献
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998.
Monolithic catalysts have received increasing attention for application in the small-scale steam methane reforming process. The radial heat transfer behaviors of monolith reformers were analyzed by two-dimensional computational fluid dynamic (CFD) modeling. A parameter study was conducted by a large number of simulations focusing on the thermal conductivity of the monolith substrate, washcoat layer, wall gap, radiation heat transfer and the geometric parameters (cell density, porosity and diameter of monolith). The effective radial thermal conductivity of the monolith structure, kr,eff, showed good agreement with predictions made by the pseudo-continuous symmetric model. This influence of the radiation heat transfer is low for highly conductive monoliths. A simplified model has been developed to evaluate the importance of radiation for monolithic reformers under different conditions. A wall gap as thin as 0.05 mm significantly decreased kr,eff, while the radiation heat transfer showed limited improvement. A pseudo-homogenous two-dimensional model combined with the symmetric model has been developed for a quick evaluation of geometric parameters for a monolith reformers. Monolithic reformers based on highly conductive substrates e.g., Ni and SiC showed great potential for small-scale hydrogen production. 相似文献
999.
针对磁介质在应用过程中出现弯曲变形的问题,需寻求既能表现出较高抗弯强度又能产生较高磁场力的磁介质。对几种特殊截面磁介质的磁场特性和抗弯强度进行了模拟和计算分析,并与常规圆形截面介质作对比,结果表明:几种特殊截面形状的磁介质产生的磁场力都要大于直径2 mm的圆形截面磁介质产生的磁场力;当量直径3 mm和4 mm的椭圆截面和正方形截面介质的抗弯强度比直径2 mm圆形截面介质大得多;几种介质中当量直径4 mm的正方形截面介质的抗弯强度和产生的磁场力都是最大的。 相似文献
1000.