(457d) Thermodynamics Analysis and Optimization of a Stirling Cycle for Lunar Surface Nuclear Power System

A nuclear powered stirling engine system in lunar surface composed of a reactor core, a hot heat exchanger, a stirling engine, a cold heat exchanger and a radiator. A mathematical model for the overall thermal efficiency of the lunar surface nuclear powered stirling engine with the heat loss of the hot heat exchanger, finite rate heat transfer, regenerative heat loss, finite regeneration process time and conductive thermal bridging losses is developed. The optimal efficiency of the system was determined by the finite time thermodynamics. The effect of some system parameters such as the absorbed temperature, the heat rejection temperature, the convection heat transfer coefficients of the hot and cold heat exchangers on the optimal efficiency were analyzed in details. The results showed that the overall thermal efficiency increased and then decreased with the absorbed temperature increase. The highest thermal efficiency was about 28%, which was far away from the corresponding carnot efficiency. Higher rejection temperature had bad effect on the thermal efficiency but could improve the waste heat rejection to the outer space. Enhancement of the heat transfer could increase the thermal efficiency. The results obtained here may provide a new ideal to design lunar surface nuclear powered stirling cycle.