Liquid helium heat sink design for experimental study of engine's plume and vacuum effects

The large horizontal ultra-low temperature heat sink, based on liquid helium cooling, could firstly realize heat sink surface temperature below 10 K in China, and is mainly applied to spacecraft-thruster vacuum plume effects' experimental study and the thermal vacuum test of satellite simultaneously. In order to minimize heat loss, the main structure of heat sink frame was removed, and the liquid helium heat sink was enclosed by a liquid nitrogen heat sink. Both of them were designed integrally so that the liquid nitrogen heat sink is not only the anti-radiation panel for liquid helium heat sink, but also the frame brace. To increase the pumping speed of heat sink, a plume adsorption pump was developed and mounted on the end of the vacuum chamber. At the experiment of vacuum plume, vacuum plume adsorption pump and liquid nitrogen heat sink were cooled by liquid helium and liquid nitrogen, respectively. The analysis was conducted for key parameters of heat sink, such as estimating the liquid nitrogen, liquid helium consumption in pre-cooling process and steady-state condition, and comparing the relationship between pumping speed of heat sink and working fluid temperature. The results show that pumping speed of the heat sink for nitrogen can reach 10 ⁷ L/s magnitude.