A new hybrid system composed of high-temperature proton exchange fuel cell and two-stage thermoelectric generator with Thomson effect: Energy and exergy analyses

Abstract A new hybrid system that integrates a high-temperature proton exchange membrane fuel cell (HT-PMEFC), a regenerator and a two-stage thermoelectric generator (TTEG) is put forward, where the TTEG takes Peltier effect, Seebeck effect and Thomson effect into account. The mathematical expressions for the power output, exergy destruction rate, electric efficiency and exergetic efficiency of the hybrid system and each component within the hybrid system are specified. The relationships between the working current density of HT-PEMFC and the electric current and the inter-stage temperature of the TTEG are obtained. Calculation results indicate that the HT-PEMFC/TTEG hybrid system allows its maximum power density and the corresponding electric efficiency and exergetic efficiency to increase by 11.8%, 17.5% and 17.7% with respect to the sole HT-PEMFC system, respectively. Furthermore, the corresponding exergy destruction rate density for the proposed hybrid system decreases by 11.4% as well. The optimum operating regions and the impacts of Thomson effect on the hybrid system energetic/exergetic performances are revealed. In the end, the influences of some decisive working conditions and designing parameters on the energetic and exergetic performances of the hybrid system are discussed.