Influence Of Non-Ideal Gas Characteristics On Working Fluid Properties And Thermal Cycle Of Space Nuclear Power Generation System

Space nuclear Closed Brayton Cycle (CBC) power generation system with Helium-xenon gas (He-Xe) as a work fluid has attracted much attention with the development of space technology. The appropriate thermophysical property model of He-Xe is the key to achieve high-precision simulation of CBC power generation system. The thermophysical property model based on virial coefficient was developed and proposed. It was compared with the ideal gas model to clarify the differences and non-ideal gas characteristics of He-Xe. The deviations of He-Xe thermophysical parameters, main cycle parameters under different temperatures and pressures were compared numerically with these models. Based on non-ideal gas properties, a thermodynamic model was developed to analyze the influence of non-ideal gas characteristics on the efficiency of a 3.0 MWth lithium-cold fast reactor power system. The results showed that He-Xe physical parameters deviated from ideal gas characteristics significantly under the molar mass of more than 40 g/mol. Lower temperature (<500K) or higher pressure (>3.0 MPa) tends to make non-ideal gas characteristics on thermophysical parameters more effective. The thermophysical property model with non-ideal gas characteristics improves the system simulation accuracy about 4.91 %. This work can be used as reference for the development, accurate simulation and assessment of space nuclear CBC power generation system. (C) 2021 Elsevier Ltd. All rights reserved.