Study on Structural Optimization and Thermal Management Performance of Embedded Composite Cooling Plate Based on Wavy Channel

An efficient thermal-management system is crucial for the safe operation of lithium batteries. In this study, an embedded composite cooling plate integrating wavy flow channels with a phase-change material (PCM) and liquid cooling was designed for the thermal management of lithium batteries. From the perspective of recovering the latent heat of a thermally saturated PCM, an evaluation method was proposed to quantitatively analyze the latent heat recovery performances, pumping energy consumptions, and overall performances of different structural configurations. The optimal structural configuration was determined by comparing the overall performances. This configuration included a circular flow shape, circular cross-section, double channels, a cross-sectional area of 36 mm², and a circular arc angle of 150°. The validity of the established numerical model was experimentally verified. Based on the optimal cooling plate structure, the heat generation of lithium batteries during 3 C rate operation was simulated using a surface heat source, and the effects of several delayed-start strategies for liquid cooling based on the PCM liquid-phase fraction on cooling performance were investigated. The results showed that the best temperature performance could be achieved by switching on the liquid cooling when the PCM liquid phase fraction reached 0.6, achieving a maximum temperature for the cooling plate of 38.32 ℃ and maximum temperature difference of 1.66 ℃, while decreasing the running time of the liquid cooling by 50.50% compared with that of the continuous mode.