Advanced thermal management system based on a novel flat evaporator loop heat pipe with high-efficiency condenser for electronic cooling

Abstract

Loop heat pipe (LHP) is a high efficient and passive heat transfer device with long heat transfer distance and high cooling capacity. In this study, an advanced thermal management system based on a novel flat evaporator LHP with high-efficiency condenser was proposed to obtain high heat transfer capacity and low energy consumption. Firstly, the cooling efficiency of two cooling heat sink units was evaluated by numerical analysis, and the optimization heat sink unit was applied in the LHP condenser. Then, the heat transfer characteristics of the flat evaporator LHP with high-efficiency condenser were researched under different charging ratios, fan voltages and LHP test directions. Finally, the energy consumption of the LHP cooling system was evaluated. The numerical results showed that the novel louver folded fin heat sink unit has a better cooling efficiency than that of the conventional straight fin heat sink unit. And the experimental results indicated that the flat evaporator LHP with high-efficiency condenser exhibited better heat transfer characteristics at the input power range from 50 W to 450 W when the charging ratio of LHP was 33.1%. At the maximum input power of 550 W, the junction temperature of the flat evaporator LHP with high-efficiency condenser was 87.93 °C at the fan voltage of 12 V, and the junction temperature of this LHP at positive gravity direction of 30° was lower than that of other LHP test directions. Additionally, the energy consumption of the efficient air-cooled LHP system was lower than one-eighteenth of that of the water-cooled LHP system.