Performance improvement of an integrated system with high-temperature PEMFC, Kalina cycle and concentrating photovoltaic (CPV) for low temperature heat recovery

Abstract

This study proposed a novel integrated system that including the high-temperature proton exchange membrane fuel cell (HT-PEMFC), Kalina cycle, concentrating photovoltaic (CPV), and the half-effect absorption refrigeration system. The waste heat discharged from HT-PEMFC was recovered to drive Kalina cycle for more power output, while the lower-grade waste heat of CPV was utilized by the half-effect absorption refrigeration cycle which provided the refrigerating capacity for Kalina cycle’ condenser cooling demand, and thus the power output of Kalina can be further improved. For examining the feasibility and evaluating the performance of the novel integrated system, a mathematical model for the proposed system was established. The results showed that the electrical efficiency of Kalina subsystem was increased by 1.217%, the exergy efficiency of PEMFC and CPV were increased by 23.99% and 9.39%, respectively, compared with the single supply system. Parameter analysis indicated that the efficiency of integrated system was improved with the increase of fuel cell operating temperature, photovoltaic operating temperature and the basic ammonia concentration, and was decreased with the increase of the Kalina separation pressure and PEMFC current density. It was also found that the total power generation efficiency of integrated system was 27.71%, which was increased by 5.03% compared with the single supply system.