Analysis and optimization of a 2-kW PEMFC-CHP system under different operating modes

This study presents a comprehensive analysis of a 2 kW proton exchange membrane fuel cell-based combined heat and power (PEMFC-CHP) system operating under different electrical and thermal following modes across six representative energy demand profiles. The system’s operational and structural parameters are thoroughly examined, and a multi-objective optimization is conducted by integrating an artificial neural network (ANN) with the Non-dominated Sorting Genetic Algorithm II (NSGA-II). Results indicate that, in winter, the constant power-thermal following mode meets the thermal demand but shortens the PEMFC lifespan due to frequent start-stop cycles. The optimized leveled distributed power mode effectively mitigates shutdowns, achieving a system efficiency (Eff_CHP) of 0.9784 and a matching degree (φ) of 0.8763, while maintaining stable thermal performance in winter and mid-season. The Eff_CHP shows an overall improvement of 7% compared with previous studies. In summer, the system operates in electrical-following mode due to reducedthermal demand. According to EWM-TOPSIS analysis, the optimal Pareto solutions achieve φ of 0.9270 and Eff_CHP of 0.9796 in winter, and φ of 0.9883, Eff_CHP of 0.9574, with hydrogen consumption of 1.9 kg in summer, confirming superior efficiency and operational coordination.