Experimental Study on the Heat Transfer Performance of Pump-Assisted Capillary Phase-Change Loop

Applied Sciences

Gaoxiang Wang¹  Jie Liu¹  Jinjia Wei¹  Xiaoping Yang¹  Cancan Zhang² 

[1] College of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an 710049, China;Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education of China, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China;

关键词: liquid cooling;    phase-change loop;    pressure difference;    heat transfer enhancement;   

DOI  :  10.3390/app112210954

来源: DOAJ

【 摘 要 】

To overcome the two-phase flow instability of traditional boiling heat dissipation technologies, a porous wick was used for liquid-vapor isolation, achieving efficient and stable boiling heat dissipation. A pump-assisted capillary phase-change loop with methanol as the working medium was established to study the effect of liquid-vapor pressure difference and heating power on its start-up and steady-state characteristics. The results indicated that the evaporator undergoes four heat transfer modes, including flooded, partially flooded, thin-film evaporation, and overheating. The thin-film evaporation mode was the most efficient with the shortest start-up period. In addition, heat transfer modes were determined by the liquid-vapor pressure difference and power. The heat transfer coefficient significantly improved and the thermal resistance was reduced by increasing liquid-vapor pressure as long as it did not exceed 8 kPa. However, when the liquid-vapor pressure exceeded 8 kPa, its influence on the heat transfer coefficient weakened. In addition, a two-dimensional heat transfer mode distribution diagram concerning both liquid-vapor pressure difference and power was drawn after a large number of experiments. During an engineering application, the liquid-vapor pressure difference can be controlled to maintain efficient thin-film evaporation in order to achieve the optimum heat dissipation effect.

【 授权许可】

Unknown