Experimental investigation on the thermal performance of vapor chamber in a compound liquid cooling system

Abstract

To develop an efficient and practicable liquid cooling system for battery thermal management, a compound liquid cooling system combining a grooved aluminum vapor chamber with a one-through flow cold plate was proposed and its thermal performance experimentally was studied. The heating power, coolant flow rate, filling ratio and tilting angle of the vapor chamber were investigated, which had an impact on the thermal resistance and temperature difference on the heating surface. The results showed that the vapor chamber with a 20%~30% filling ratio had the smallest thermal resistance and preferable temperature uniformity in horizontal configuration. Due to the heat and mass transport of phases along the longitudinal direction inside the vapor chamber, the temperature difference of the heating surface arising from the temperature rise of the coolant could be suppressed effectively. To evaluate the suppressed effect on the temperature difference of the heating surface, the suppression ratio was proposed. The suppression ratio on the heating surface rose with the increase in heating power and the decrease in flowing rate. The thermal resistance and temperature uniformity of the vapor chamber deteriorated in tilting configuration. The vapor chamber at a positive tilting angle configuration performed better compared with that at a negative tilting angle configuration. At 20%~30% filling ratio, the suppression ratio of the temperature difference on the heating surface could be achieved at 0.78 under positive tilting angle configuration.