Establishment and analysis of a new steady-state operation model of loop heat pipe

Abstract

In this study, an original loop heat pipe (LHP) was used as the physical model. Based on the variable conductivity mode (VCM) and constant conductivity mode (CCM) of LHP, a steady-state mathematical model of the LHP was established, and the operational characteristics of the LHP were simulated by this mathematical model. The simulated results indicated that the mathematical model can accurately assess the operational temperature of the LHP with a flat evaporator. As the heat input increased, the length ratio and length of two-phase region in the condensation line, and the pressure drop of each component of LHP increased gradually. When the heat input was 750 W, the length of the two-phase region in the condensation line was 230.5 mm, which accounted for 42.3 % of the total length of the condensation line. The pressure drop of the condensation line was the highest in the entire heat input range from 50 W to 750 W compared to other components of the LHP. The ratio of heat leak to heat input decreased with the increasing of heat input. The largest ratio of heat leak to heat input of 5.93 % was obtained at the heat input of 50 W.