Performance comparison of several heat pump technologies for fuel cell micro-CHP integration using a multi-objective optimisation approach

Although the integration of heat pumps with fuel cells for micro combined heat and power is a viable solution for reducing hydrogen energy consumption, recent studies have typically only considered the vapour compression cycle as the selected heat pump. This research proposes a multi-objective optimisation methodology to analyse the performance of several candidate heat pump technologies (the Peltier device, trans-critical R744 cycle, and vapour compression cycle), and determines the most suitable option for the hybrid fuel cell and heat pump (FC-HP-μCHP) system. Their mathematical models have been separately developed and utilised in a transient simulation for satisfying the power and heat demands of a domestic home. The selected optimisation objectives include maximising the hydrogen energy consumption efficiency and minimising the combined capital and yearly maintenance costs. Results show that the vapour compression cycle is the dominant solution. This is because it has the highest coefficient of performance, and effectively reduced the fuel cell stack and lithium battery’s maintenance costs. The heat pump’s coefficient of performance is found to have higher importance than its own economic cost.