Thermodynamic modeling and exergy analysis of a stirling cycle for space power generation

Resumo

© ECOS 2020.All right reserved.Focusing on the great challenges of space exploration for the coming decades, there is a need for more efficient and compact energy conversion systems for space applications. To this end, a thermodynamic model was applied to analyze the energy and exergy efficiency of space nuclear power plant that operates with freepiston Stirling cycle for deep space exploration purposes. The model considered conduction losses (thermal bridge), heat pipe efficiency, finite regeneration time, and radiation losses. Thermodynamic irreversibilities of the reactor, regenerator, and radiator were computed in order to find which component is accountable for the highest exergy destruction. Results have shown that most of the exergy is destroyed in the regenerator and the radiator. With the increasing radiator area, the irreversibility of the radiator tends to decrease, but the mass per power output ratio also decreases. The optimum power output per radiator area and mass per radiator area pointed for 2.697m2of the radiator area for this energy conversion system. Furthermore, it was evidenced that the regenerator effectiveness considerably influences the overall cycle efficiency, as well as reference temperature (environment) and cold source temperature. These results can provide relevant guidelines for future design of a space power plant where the Stirling cycle is the chosen dynamic energy conversion system.

Palavras-chave