Study on the thermal-mechanical coupling characteristics and influencing parameters of heat pipe radiator under accident conditions

Space reactors, due to their strong environmental adaptability, high power output, small size, and long lifespan, are the most important direction for the development of nuclear energy systems in space. The waste heat of the space reactor system needs to be dissipated through a radiative heat exchanger. The current numerical analysis of the heat exchanger predominantly emphasizes heat transfer phenomena while neglecting the effect of mechanical properties. This study utilizes a self-developed, highly accurate thermal-mechanical coupling calculation program to conduct a numerical analysis of the heat pipe radiator. The main objective is to acquire a comprehensive understanding of its thermal-mechanical coupling characteristics and evaluate the effects of various accident conditions on the radiator. The results indicate that the heat dissipation power obtained from the thermal-mechanical coupled calculation is 0.42% higher than that obtained from the standalone heat transfer calculation. Single axial heat pipe failure leads to a 9.13% decrease in heat dissipation power for the affected module, while two axial heat pipes failure results in a 21.17% decrease. The ability of the heat pipe radiator to meet the heat dissipation power requirements under different failure conditions indicates its capacity to effectively respond to a wide range of incidents, thereby emphasizing its superior safety level.