Operation performance analysis of a liquid metal droplet radiator for space nuclear reactor

Liquid droplet radiator (LDR) is the frameless space radiator designed for heat dissipation of large-power space nuclear reactors. This paper analyzes the radiative heat transfer and evaporative characteristics of liquid metals adopted in LDR including lithium, aluminum and tin. Firstly, the cooling process of different working fluids is simulated and the temperature distribution at the droplet collector is obtained. The radiant energy of per unit mass fluid with different optical thicknesses and temperatures is calculated. Secondly, the evaporative characteristics of the working fluid are studied. Finally, the system operation performances are evaluated including the system life and radiant energy with different optical thicknesses and temperatures. Results show that liquid lithium is appropriate for heat dissipation system working under 600 K, while liquid aluminum and tin are more appropriate for working under 1200 K and 1500 K, respectively. This work provides the theoretical support for liquid droplet radiator thermal design.