THE INFLUENCES OF TILTING CONFIGURATION AND HEAT FLUX ON THE TEMPERATURE UNIFORMITY OF VAPOR CHAMBER IN A LIQUID COOLING SYSTEM

The performance of a grooved vapor chamber is tested under different tilting configurations in a liquid cooling system, which is aimed to obtain a better temperature uniformity combined with a one-through flow cold plate for battery thermal management. A three-dimensional model of the coupled heat and mass transfer with the volume of fluid (VOF) method and evaporation-condensation model is developed and computed by an improved transient calculation method. According to the flowing characteristics of phases, we find that two phases smoothly flow in the counterclockwise direction under the positive tilting configuration. The assistance of the buoyancy force and gravity would improve the temperature uniformity under the positive tilting orientation. The heat of the vapor would be driven from the high-temperature region to the low-temperature region, and the condensed liquid would return to the high-temperature region in time. The temperature difference can be kept within 3.14°C under the positive tilting angle of 20°. On the other hand, the obstruction of the two-phase flow will appear under the negative tilting orientation which will enlarge the temperature difference to the 4.43°C under the negative tilting angle of 20°. To assess the temperature uniformity under different operation conditions, the suppression ratio of the temperature difference on the heating surface is put forward. The impact of the tilting configuration and heat flux on the suppression ratio of the heating surface has been investigated and discussed.