Thermodynamic Analysis and Optimization of Mobile Nuclear System

This paper develops a system–component integrated design method for a closed Brayton cycle in a nuclear-powered emergency power vehicle, optimizing the thermodynamic performance by varying the maximum operating temperature and pressure, minimum operating temperature, helium–xenon gas molar mass, and PCHE parameters to maximize the specific power and thermal efficiency. The key results are as follows: (1) The maximum allowable pressure decreases with the temperature, and the specific power increases for both the SRC and the IRC without considering the ultimate heat sink. (2) The PCHE weight is minimized at a helium–xenon gas molar mass of 25 g/mol, while the turbomachine’s weight decreases with an increasing molar mass, leading to an overall system weight reduction. (3) The thermal efficiency decreases with lower minimum operating temperatures, optimizing at 350 K due to a precooler weight increase. (4) The thermal efficiency plateaus after a certain number of PCHE channels, with the recuperator effectiveness significantly impacting the performance. (5) The SRC, with a specific power and a thermal efficiency of 194.38 kW/kg and 39.19%, is preferred over the IRC for the SIMONS due to its mobility and rapid deployment. This study offers a comprehensive analysis for optimizing closed Brayton cycle systems in emergency power applications.