Theoretical analysis of steady-state performance of a loop heat pipe with a novel evaporator

•A loop heat pipe (LHP) with novel evaporator is proposed.•The novel evaporator features very small heat leak from the evaporator to the CC.•The LHP with novel evaporator has improved operating stability and reliability.•Mathematical model of the LHP with novel evaporator is established.•The operating characteristics and heat transfer limit are theoretically analyzed.

A novel evaporator that features very small heat leak from the evaporator to the compensation chamber (CC) is proposed to improve the operating performance and reliability of loop heat pipes (LHPs). The mathematical model of the steady-state operation of the LHP is established, and its operating characteristics and heat transport limit are theoretically investigated. The modeling results show that the novel evaporator design can significantly reduce the heat leak from the evaporator to the CC. In this new evaporator design, the liquid flow pressure drop in the evaporator wick becomes the major component of the total pressure drop, and the LHP operation becomes insensitive to the adverse elevation. The heat transport limit of the LHP is found to be determined by the boiling limit under low adverse elevation, and by the capillary limit at relatively large adverse elevation.