涡轮增压型甲醇重整高温质子交换膜燃料电池推进系统性能评估

To address the performance degradation of high temperature proton exchange membrane fuel cell (HT-PEMFC)due to the environmental characteristics of low temperature and low pressure at high altitude, this paper proposes two hybrid propulsion systems for methanol reforming HT-PEMFC coupled with turbochargers. According to the different gas flow paths,it can be categorized into the turbocharger-forward and the turbocharger-backward schemes. The performance potentials of both the schemes are evaluated and compared through a thermodynamic model. The results show that pressurization not only enhances the output performance of the HT-PEMFC but also significantly increases the cathode feed temperature. When the aircraft is operated at an altitude of 7 km and the pressure ratio exceeds 3, the cathode feed temperature is sufficient to meet the operational requirement without the need for auxiliary heating equipment. By integrating a turbocharger into the system, it is possible to significantly increase the specific thrust and equivalent power of the system and achieve a significant reduction in the equivalent fuel consumption rate, but it will also cause a reduction in the thrust of the nozzle. In addition, due to the heat transfer temperature difference limitations of the reformer, the turbocharger-backward scheme requires additional injection of methanol fuel into the catalytic combustor at a higher air stoichiometry ratio and fuel utilization ratio. The result of the comprehensive thermodynamic performance analysis shows that the turbocharger-backward scheme is more advantageous in terms of system energy efficiency and hence can be considered as the best option.