Performance analysis of a novel system coupled steam reforming and solid oxide fuel cells with anode exhaust recirculation for power supply and thermal management of hypersonic vehicles

To address the increasing demand for electricity and thermal management of hypersonic vehicles, a thermal management system is proposed in this study combining the characteristics of high chemical heat sink of endothermic steam reforming (SR) and the satisfactory energy conversion efficiency of solid oxide fuel cells (SOFCs). The scheme of SR facilitated by SOFC exhaust for wall cooling of scramjets is pioneered by this study avoiding additional water carryover. Multi-dimensional models are established to evaluate the thermal protection and power generation performance of the system. The results indicate that the system exhibits satisfactory thermal protection performance, with the peak wall temperature reduced from 1101.79 K to 1032.9 K compared to conventional technology. Further, the megawatt-level power generation could be realized with 52.31 % thermal efficiency and 1.3 kW/kg power density by this system, which is superior to the conventional technology. Subsequently, the optimal power generation (1669.53 kW) and power density (1.63 kW/kg) under the thermal protection constraints are obtained by optimized energy cascade utilization. Finally, the parameterization results indicate that for the megawatt-level target power, the optimal system performance is achieved when 0.31 of the working fluid at the cooling channel outlet is recirculated to SOFCs.