MCFC-并联TTEG混合系统的性能优化

为有效回收熔融碳酸盐燃料电池产生的余热,提出一种由熔融碳酸盐燃料电池(MCFC)、两级并联温差发电器(TTEG)和回热器组合而成的混合系统模型。考虑MCFC电化学反应中的过电势损失和混合系统中的不可逆损失,通过数值分析得出混合系统的输出功率和效率的数学表达式,获得混合系统的一般性能特征,讨论MCFC电流密度与温差发电器的无量纲电流之间的关系,确定混合系统的优化工作电流区间。结果表明,该混合系统的功率密度和效率分别比单一的MCFC系统提高46.9%和35.0%。此外,考虑了热电材料性能指标等对热电能量转换的影响,为进一步开展燃料电池与两级温差发电器的混合系统的研究提供参考。

PERFORMANCE OPTIMIZATION OF MCFC-PARALLEL TTEG HYBRID SYSTEM

In order to recover the waste heat produced in molten carbonate fuel cells(MCFCs),this article proposes a hybrid system mainly consisting of a MCFC,a parallel TTEG and a regenerator.Considering the over potential loss in the electrochemical reaction of MCFC and the irreversible loss in the hybrid system,the mathematical expressions of the equivalent output power and efficiency of the hybrid system are obtained through numerical analysis.Then the general performance characteristics of the hybrid system are summarized.It is followed by a discussion on the relationship between the electric current density of MCFC and the dimensionless electric current of the thermoelectric element.Finally,the optimized operating current interval of the hybrid system is determined.The hybrid system is found to improve the power density and efficiency by 46.9%and 35.0%,respectively compared with the MCFC.In addition,the impacts of the performance index of thermoelectric materials on the thermoelectric energy conversion are analyzed.It hopes to provide a reference for the study on the hybrid systems of fuel cells and two-stage parallel thermoelectric generators.