Optimization of an HT-PEM fuel cell based residential micro combined heat and power system: A multi-objective approach

This article presents multi-objective optimization of an HT-PEM fuel cell based micro CHP system under steady-state operation by employing the mathematical model of the plant previously developed by our group. Different optimization procedures have been carried out to find the optimal points while considering two sets of objective functions: I) thermal power generation and net electrical output and II) net electrical efficiency and thermal efficiency. In the first part of the work, optimization has been performed at full load operation with electrical and thermal generation as objectives. The obtained Pareto frontier shows the capability of the system to cater a broad range of electrical demand (21.0 kW-29.4 kW) while offering the maximum achievable thermal generation. In the next step, in order to find the optimal operating conditions of the system while addressing specific thermal and electrical load profiles, a series of Pareto fronts have been acquired at different fuel partialization levels. Finally, using the primary energy saving (PES) index, the best operating points, in terms of electrical and thermal efficiency, have been determined. It was observed that the net electrical efficiency up to 32.3% and thermal efficiency as high as 61.1% can be reached through the optimization.