The evaluation of hydrogen production of a multistage cooling system's performance

In the present research, a new cycle of scramjet open recuperator cooling to produce power and hydrogen is presented. In which, the power generation subsection uses the waste heat in the scramjet cooling process as a cycle heat source and produces electric power. In this research, some of the power generated in the cycle is used to power a Polymer Electrolyte Membrane (PEM) electrolyzer that produces hydrogen. An analysis of the energy and exergy has been conducted to assess the system's performance. With a fuel mass flow rate of 0.45 kg/s, the cooling capacity of the system is 10.2 MW, net power production is 4.1 MW, and 45.1 kg/h of hydrogen is produced. The exergy analysis revealed that the PEM electrolyzer had the highest exergy loss at over 48%, followed by the first cooling path at over 32%. The energy and exergy efficiency of the system are 14.2% and 19.2%, respectively. The parametric study indicated that increasing the mass flow rate leads to higher power production and cooling capacity. Additionally, at a constant fuel mass flow rate, power production increases with higher pressure behind the pump.