Numerical simulation and conceptual design of an MW-grade space heat pipe radiator

Abstract

In recent years, nuclear reactor systems have been widely used in the space. The design of a radiator is of great importance as its heat dissipation performance directly determines the upper limit of the overall output power of the space nuclear propulsion system. In the present paper, a space radiator is divided into heat dissipation units, among which the heat pipes and fins are numerically modeled and analyzed. Kalium was selected as the working medium in the heat pipe, and the size of the heat pipe was designed based on the limitations, with the length of the evaporation section and the condensation section as 150 mm and 250 mm, respectively. VOF- Lee model was applied to simulate the phase-change heat transfer process inside the heat pipe, by setting the parameters of the hot-end temperature, the cold-end heat flux, etc. In addition, S2S model was used to examine the influences of thickness and width of the fin on the heat dissipation performance, so as to determine the optimal fin size. Finally, the heat pipes and fins were assembled into a whole radiative cooling system, with a mass-area ratio below 7 kg/m2 and a total heat dissipation power at 3.58 MW.