固体氧化物燃料电池与质子交换膜燃料电池联合系统的建模与仿真

Modeling and Simulation of a Hybrid System Combining Solid Oxide and Proton Exchange Membrane Fuel Cell

建立一种新型的发电系统结构——固体氧化物燃料电池(solid oxide fuel cell,SOFC)与质子交换膜燃料电池(proton exchange membrane fuel cell,PEMFC)联合发电系统,在该联合系统中SOFC不但可产生电能,同时为PEMFC提供富氢的重整气产生额外电能,提高了燃料能量转换率,也节省了外置重整器的设备消耗。该文基于质量、能量平衡并耦合电化学知识建立了SOFC-PEMFC联合发电系统模型。详细讨论了系统参数(燃料利用率、空气与燃料流量比和燃料流量)对系统性能的影响。仿真结果表明,在本文设计工况下,SOFC-PEMFC联合发电系统的发电效率和系统能源综合利用效率分别为54%和72.3%,高于同一功率等级下的独立SOFC发电系统和重整器-PEMFC发电系统;另外,合理的空气与燃料流量比可以改善系统性能;SOFC燃料利用率为75%时,系统发电效率达到最大;燃料流量对系统发电效率基本没有影响。

This article established a new electrical system structure-solid oxide fuel cell （SOFC） and proton exchange membrane fuel cell （PEMFC） hybrid power generation system. In this system, a high-temperanu＇e solid oxide fuel cell not only was used to produce electricity but also supply the reformed gas to a polymer electrolyte membrane fuel cell to generate extra electricity simultaneously, which can improve the energy conversion efficiency and save the cost of reformer significantly. This paper established the mathematics model of SOFC-PEMFC hybrid system base on mass and energy balance coupled with electrochemistry theory. The particular discussion of the effects of the system parameter （fuel utilization, air to fuel ratio, and fuel flow-rate） on the system performance was performed. Results show that the electrical efficiency and system efficiency predicted for the hybrid system are shown to be 54% and 73.3% respectively, which better than a reformer-PEM system and a SOFC-only system with the same power output. Reasonable air to fuel ratio could improve the performance of the hybrid system. Moreover, electrical efficiency reaches the maximum when the value of fuel utilization in SOFC is 75% and fuel flow-rate has no effect on the electrical efficiency.