A Non-ideal Gas Model Proposed for Space Nuclear Power Generation System

A study on space nuclear power generation system, led by the research group of Jie Yu/ Zhibin Chen from the Institute of Nuclear Energy Safety Technology, Hefei Institutes of Physical Science(HFIPS), has revealed the non-ideal characteristics of Helium-Xenon(He-Xe) gas, which is the working fluid of the space nuclear power generation system.

Space nuclear Closed Brayton Cycle (CBC) power generation system with He-Xe gas as the working fluid has attracted much attention with space technology development. The establishment of appropriate thermophysical property model of He-Xe gas is significant to achieve high-precision simulations of space nuclear CBC power generation system.

In this research, the team developed the non-ideal gas thermophysical property model on the basis of virial coefficient and compared the proposed model with the widely applied ideal gas model of He-Xe gas.

Based on non-ideal gas properties, researchers developed a thermodynamic model to analyze the influence of non-ideal gas characteristics on the efficiency of a 3.0MWth lithium-cooled fast reactor power system. The results showed that He-Xe gas physical parameters significantly deviate from ideal gas characteristics under molar mass of greater than 40 g/mol. Lower temperature (<500K) or higher pressure (>3.0MPa) tends to lead more intensive non-ideal gas characteristics. The proposed non-ideal gas model improves the system simulation accuracy around 4.91%.

This work can be used as reference for the development, accurate simulation and assessment of space nuclear CBC power generation system.

Link to the paper: Influence of non-ideal gas characteristics on working fluid properties and thermal cycle of space nuclear power generation system

Space nuclear power generation system (Image by XU Chi)

Figure 2. Verification of the non-ideal gas properties computational model