Steady state modeling and characteristic analysis of propylene flat loop heat pipes

The flat loop heat pipe (LHP) using propylene as the working fluid has advantages such as low-temperature adaptability and light weight, making it the vital technology for solving the thermal control problems of deep space exploration missions. Urgent demands are raised to investigate the heat transfer performance and characteristics of propylene flat LHPs. This paper established a steady-state model, which can accurately predict the operating temperature of a propylene flat LHP. The maximum heat transfer capability and flow resistance characteristics of propylene LHP were analyzed. The calculation method was improved, which is used for computing the volume of the compensation chamber and the mass of working fluid. A design of an LHP with a secondary compensation chamber is put forward. The propylene LHP’s operating temperature range is expanded by the design, which also reduces its weight and volume.