Cogeneration of power and hydrogen using Scramjet cooling system :Energy and exergy analyses

In the current study, a new integrated system is provided to prevent waste energy and reduce power consumption. This system consists of a cascade refrigeration system (for cooling) and an Organic Rankine cycle(ORC) (for power generation). These two cycles are combined through a heat exchanger. In fact, this heat exchanger acts as a condenser for the cascade refrigeration cycle and evaporator for ORC. The waste heat of the cascade refrigeration cycle is used to handle the ORC. In this way, a part of the power consumption of the cascade refrigeration cycle is satisfied by ORC. Thermodynamic simulation of the proposed system is carried out via Engineering Equation Solver(EES) software. A parametric study is done to evaluate the effects of the operational parameters on the performance of the integrated system. In addition, different working fluids are used in cascade refrigeration and ORC cycles. The results showed that by using the working fluids of R245fa, R717, and R141b in order in the low-temperature refrigeration cycle, high-temperature refrigeration cycle and ORC, one can produce cooling at -50 ° C and also reduce the power consumption up to 48.69% in the cascade refrigeration cycle.