Thermodynamic and mass analysis of a novel two-phase liquid metal MHD enhanced energy conversion system for space nuclear power source

The higher-efficiency and more lightweight space nuclear power source is one of the most important prerequisites for future deep space exploration. Magnetohydrodynamic (MHD) power generation is the potential technical route to achieve significant improvement in energy conversion performance, but technology is not yet mature. By combining the characteristics of MHD and closed Brayton cycle (CBC) power generation systems, a novel quasi-Ericsson cycle with performance advantages is proposed in this study. The estimation method for the MHD power generator is refined and the thermodynamic and mass analysis models for the novel system are established. Comparative studies between the LMMHD-CBC cycle and the traditional CBC cycle are conducted under various boundary conditions and internal parameters. The results indicate that the LMMHD-CBC cycle increases the electricity generation per unit mass flow rate of working fluid under the same temperature conditions, thereby achieving a reduction in the specific mass of the power generation system. The LMMHD-CBC system is more suitable in lower reactor temperatures and higher radiator temperature conditions. Within the parameters range considered in this study, the relative reduction in specific mass compared to traditional CBC systems reaches up to 30.84 %.