Abstract:

To investigate the influence of heat dissipation factors on the comprehensive cooling capability for the rectangle power lithium battery, a three-dimensional transient thermal mathematical model was established under different operating conditions during charging process, making use of which the battery temperature field distribution was simulated at different charging current, ambient temperature, convective heat transfer coefficient and thermal emissivity based on the finite element method. In the meantime, the simulation results were verified experimentally, according to the results obtained by verified finite element thermal model, using the virtual orthogonal experiment method, the importance degree of influence factors was calculated and analyzed. The optimum combination of influence factors was attained, and the temperature field distribution of the original scheme(practical influence factors) and the optimized scheme(the optimum influence factors) was simulated using finite element thermal model. The results show that the thermal model of finite element is credible, and the most significant factor on the battery comprehensive cooling capacity is the charging current, whose important degree is 0.53, while the important degree of the ambient temperature is 0.21, the important degree of the convective heat transfer coefficient is 0.15, and the important degree of the thermal emissivity is 0.05, playing the least important part in the battery heat dissipation. In conclusion, the battery comprehensive cooling performance after optimization is better than that before optimization, and the virtual orthogonal experiment method has certain value of practical application in battery cooling scheme design and optimization.

Key words: heat production model, influence factor, virtual orthogonal experimental method, variance analysis