Experimental investigation on the start-up performance of a loop heat pipe with three flat disk evaporators combined

Abstract

To promote the heat transport applicability of the loop heat pipe(LHP) for high power and multi-heat sources, a multi-evaporator loop heat pipe(ME-LHP) system with three flat disk evaporators equipped with separate vapor lines was proposed and experimentally studied for the first time. The effects of the interaction between evaporators, the heat load distribution, and the gravity-assisted angle on the startup behavior of ME-LHP were investigated respectively. The results show that with the separated-vaporline structure, the adverse impact between evaporators was greatly reduced. The best performance appeared when all three evaporators were involved. At unequal heat load working conditions, the ME-LHP obtained the optimal startup performance when high heat load was applied on evaporators with a superior position in liquid separation. Besides, the outlet temperature of all evaporators tended to be consistent, even if multiple evaporators worked under unequal heat loads. The gravity-assisted angle affected the start-up process by changing the non-uniformity of liquid distribution. Compared with the gravity-assisted tilt θ = 10°, the highest performance was improved by 77 % for θ = 2°, and the peak load could reach 300 W. The present study may extend the application of the flat plane type of loop heat pipe for solving the multi-heat-sources dissipation problem.