Development and Test Results of a Multi-Evaporator-Condenser Loop Heat Pipe

Abstract

Results are presented of the development and tests of a 1 m long ammonia ramified loop heat pipe, with two cylindrical evaporators (24 mm in diameter with an active zone length of 150 mm) and two condensers (length 200 mm, diameter 24 mm), made as pipe-in-pipe heat exchangers. Tests of the device at different orientations in 1-g have shown that it can efficiently operate at symmetrical and non-symmetrical heat load distributions between the evaporators, and also at different temperatures of the condensers cooling. The maximum total transport capacity is 1100-1400 W. Shutting down the active cooling of one condenser results in an abrupt decrease in the maximum transport capability of the device.

A review of thermal performance in multiple evaporators loop heat pipe

“…For ME-LHP modeling, Maydanik [34] brought up a hydrodynamic model to calculate the maximum capacity of an LHP with multiple evaporators and condensers at different The analytical model employed a nodal approach for the finite difference solution scheme. This model is capable of simulating the ME-LHP performance within the capillary limit and the predictions will be inaccurate once the capillary limit has been exceeded.…”

“…The evaporator with a titanium wick showed three times weaker in capillary limit than the evaporator with a nickel wick. The capillary limit tested in open literatures for LHP with two evaporators is 240W in Chang and Nagano [44], 120 W in Ku and Ottenstein [39], 110-140W in Maydanik et al [34], 100 W for miniature 2E-2C-LHP with 8mm evaporator diameter in Habtour [49], 120-140 W for 2E-2C-LHP with evaporator outer diameter of 15mm in Ku [50].…”

Integrated Mechanical, Thermal, Data, and Power Transfer Interfaces for Future Space Robotics

“…The LHP principle allows creating ramified heat-transfer devices including different numbers of evaporators and condensers situated at different orientations, making themselves particularly suitable for thermoregulation systems of spacecraft, reducing mass, and increasing compactness (Maydanik, 2003 ).…”