Comprehensive performance study of boiling battery temperature management system with trapezoidal fins microchannel cooling plate

Abstract

A flow-boiling battery temperature management system (BTMS) is considered a valid way to achieve heat dissipation of high-energy-density batteries at high charging and discharging rates due to its strong heat-transfer performance. A microchannel cooling plate with trapezoidal fins (TFMP) to introduce secondary flow between adjacent main channels is proposed in this study, as part of a flow-boiling BTMS to cool rectangular lithium-ion batteries. The results show that, as the inlet Reynolds of the coolant number inside the cooling plate increases from 25 to 825, the heat transfer mode of the coolant becomes from boiling heat transfer to single-phase convective heat transfer. Meanwhile, in the boiling heat-transfer mode, compared with traditional straight channels, as the long edge length of the trapezoidal fins, the width of the secondary channel, and the bottom angle of the fins increase, the temperature characteristics of the batteries, and the heat transfer performance and overall performance of the cooling plate are improved, while the flow resistance and entropy production of the cooling plate are also smaller. At a 3C discharge rate, when the Reynolds number is 450, the coolant is boiling heat-transfer mode, mainly, and the BTMS has the highest comprehensive performance. At this time, compared to traditional straight channel cooling plate, the heat transfer performance and the performance evaluation criterion of the TFMP are enhanced by 1.89 and 1.31 times, respectively, while the irreversible loss is only 64% of it, and the maximum temperature of the batteries (Tmax) in the BTMS is 34.03 °C, their maximum temperature difference (ΔTmax) is 2.51 °C, which is 2.55 and 1.37 °C lower than the BTMS with traditional straight channel cooling plate, respectively.