Thermodynamic performance of brayton cycle energy conversion system of spacecraft

As a promising proposal for the future space exploration, which uses super critical CO2 as working fluid, Brayton cycle space nuclear power system is still at early research stage about thermodynamic analysis. Therefore, the work about super-critical CO2 Brayton cycle with sodium cooled fast reactor has been done. The expression of CO2 real gas enthalpy and RK equation has been built during the analysis process. Then the effects of highest temperature in cycle, pressure ratio and temperature difference of cooler-side of low temperature recuperator (LTR) on cycle efficiency have been discussed. Meanwhile, the diagram of output power varying with pressure ratio has been obtained from the calculation results of super-critical CO2 Brayton cycle model. Finally, the influence of pressure ratio and temperature difference of cooler-side of LTR on radiator area has been studied. The results show that cycle efficiency will increase effectively by improving highest cycle temperature or pressure ratio. But, heat transfer condition will deteriorate when pressure ratio raise, while low pressure ratio will lead to high heat load of high temperature recuperator. Thus, the suitable scope of pressure ratio is 3.0~3.2.