LAUSR

Abstract Thoroughly understanding the influence of evaporator design on the characteristics of loop heat pipes (LHPs) is of great significance to develop optimal microchannel structures for high-power microprocessors. In the current work, the parallel microchannel loop heat pipe (PMLHP) and the self-similar fractal microchannel loop heat pipe (SFMLHP) were designed, fabricated and experimentally analyzed from the aspects of filling ratio and inclined angle, and then the heat transfer performances were compared with the dendritic bionic microchannel loop heat pipe (DBMLHP) under the same experimental conditions. The results show that PMLHP had four operation phenomena similar to DBMLHP while SFMLHP only had two operation phenomena. The start-up performances of PMLHP and SFMLHP were the best when the inclined angle was 90°. When the inclined angle was fixed at 90°, the optimal filling ratios for PMLHP and SFMLHP to yield the optimal thermal resistance were rather different. Through comparative analysis, it can be concluded that the overall heat transfer characteristic of DBMLHP was the best of the three under specified conditions. However, the average temperature fluctuation range in DBMLHP evaporator was the largest in the stable operation. The results provide valuable guidance on the choice of better and more suitable evaporator structure for microchannel loop heat pipes.