Experimental study on an integrated system of thermosyphon loop and vapor compression assisted with phase change material for pulse heat load

Abstract

In order to safely and energy-efficient handle the pulse heat load of avionics, the paper proposes an integrated system of thermosyphon loop and vapor compression cycle, especially assisted with phase change material (PCM). Under low heat load and heat sink temperature, the system operates as a thermosyphon loop (TL) for energy saving; otherwise as a vapor compression cycle (VCC) for safety. A prototype of the integrated system was developed, where a whole three-dimensional (3D) printed structure worked as the evaporator of the system, consisting of a mini-channel cold plate and a high thermal-conductivity matrix containing PCM. The dynamic performance of the proposed system has been experimented under different pulse heat loads and heat sink temperatures, and compared to the integrated system without PCM and a traditional VCC. The proposed system can handle a peak heat load of 1000 W for 120 s without running the compressor, saving 100 % energy compared to traditional VCC. The PCM enhances both the safety and energy efficiency of the integrated system. On the one hand, it reduces wall temperature during the transition from TL to VCC, avoiding overheating issue. On the other hand, it reduces the operating time of VCC, which is more significant with lower peak heat load and heat sink temperature. Overall, the integrated system assisted with PCM is a promising solution for solving pulsating heat loads.