采用可逆质子交换膜燃料电池/膨胀机的综合能源系统性能研究

Integrated Energy System Based on Reversible Proton Exchange Membrane Fuel Cell and Expander

为提高可再生能源在冷热电联供系统中的利用率,提出一种以可逆质子交换膜燃料电池(RPEMFC)和膨胀机为主要部件的新型冷热电联供综合能源系统,通过引射器和膨胀机回收电解池氧气侧的压力能,以RPEMFC电堆的冷却回路和膨胀机出口冷气分别对外供热和制冷。为获得系统中主要设备运行参数对系统性能的影响,建立了系统的热力学模型,进而揭示了系统效率、效率、压缩机耗功、膨胀机回收功、系统制热制冷量等参数的变化规律。研究结果表明:当RPEMFC电堆以50kW的发电功率运行时,系统发电效率为56.2%,热效率为35.2%,总效率为91.4%,效率为54%,且在15~85kW的发电功率变化范围内系统能效均超过89%;系统能量效率及效率对引射器流量比及引射器工作流压力的变化较为敏感,并以影响系统发电效率为主;压缩机出口压力变化对系统能效影响不大,但压缩机出口压力增大有利于系统增加产冷量。

To improve the utilization of renewable energy in combined cooling,heating and power system(CCHP),a new scheme of CCHP based on a hybrid of reversible proton exchange membrane fuel cell(RPEMFC)and expander is proposed,where the pressure energy of electrolyzed oxygen is recovered by ejector and expander.The exhaust heat and cool air of RPEMFC and expander are used to improve the system efficiency.A thermodynamic model is developed to conduct the sensitivity analysis of energy efficiency,exergy efficiency,energy consumption of compressor,energy recovery of expander,heat and cool air supply.The results show that the 50 kW RPEMFC based CCHP system can obtain electrical efficiency 56.2%,thermal efficiency 35.2%,overall efficiency 91.4%,and exergy efficiency 54%.The energy efficiency of the system exceeds 89% within the range of power generation from 15 kW to 85 kW.The exergy efficiency and energy efficiency of the system are sensitive to the changes of ejector flow ratio and the pressure of ejector driving flow.The change of compressor outlet pressure has little influence on the energy efficiency of the system,but its increase is beneficial to the cool air supply of the system.