关键词: 嫦娥五号, 热控, 热总线, 流体回路, 水升华器

Abstract: In view of the thermal control problem faced in lunar robotic sampling mission of Chang'e-5 complex of lander and ascent vehicle, a lightweight pumped fluid loop thermal bus and design method were proposed. Through the thermal bus, the "structural plate fixed radiator + high temperature water sublimator" was jointly constructed as a set of combined heat sink to realize the integrated thermal management of the probe energy and the separation and reconstruction. The dry weight of pumped fluid loop is 15 kg, accounting for less than 20% of the weight of the thermal system. The on-orbit flight data show that the lightweight pumped fluid loop thermal bus works normally, the maximum temperature difference of thermal bus is no more than 7℃, and the heat dissipation capacity is 30 W/kg. The pressure variation curve of working medium venting in the process of the thermal bus separation and reconstruction before ascent vehicle take-off is consistent with the ground experimental results. All performance indexes of the pumped fluid loop on-orbit meet the design expectations, which verify the rationality and feasibility of the lightweight pumped fluid loop thermal bus technology, and can also provide some reference for the thermal control design of other types of spacecraft.

Key words: Chang'e-5, thermal control, thermal bus, fluid loop, water sublimator