A PARAMETRIC STUDY ON THE THERMAL HOMOGENEITY OF VAPOR CHAMBER IN A BATTERY COOLING SYSTEM

Abstract

For the battery cooling system, the large temperature difference of the coolant between the inlet and outlet leads to a decrease in the thermal homogeneity of batteries. To improve the thermal homogeneity, a designed composite liquid cooling system was analyzed combined with a grooved vapor chamber and a cooling plate. The parametric study on the thermal homogeneity was conducted including the height, width, length of grooved wick, filling ratio, flow rate of coolant, heat flux, and inclination angle. The results show that a preferable thermal homogeneity can be obtained at 20% filling ratio as the height and width of the channel increase, especially under the positive inclination angle of 20°. The heat source surface can be kept uniform within the temperature difference of 5°C in spite of the temperature rise of coolant up to 11.5°C under the flowing rate of 8.32 × 10^-4 kg/s. An empirical correlation of the "suppression ratio," containing the structural and operating parameters, is summarized to evaluate the suppressing function of the vapor chamber on the temperature difference of coolant. This research is aimed to provide a scientific basis for predicting the thermal homogeneity of the vapor chamber in a battery liquid cooling system.