Air-cooled battery thermal management technology is well developed and inexpensive, but the small convection coefficient of air limits the heat dissipation capability of the system. In this paper, a wet pad is applied to pre-cool air before it passing through the battery pack. Fluent software is used to establish a model of the lithium-ion battery pack to simulate the surface temperature of the battery. Comparative study on the temperature distribution of the same battery pack with and without the wet pad is conducted under various ambient conditions and air velocity. Simulation results show that better cooling performance of the wet pad can be obtained at higher and arid ambient conditions. Increased air velocity brings in slightly reduced cooling efficiency of the wet pad. But it can enhance the heat transfer among airflow and the battery pack. Overall, thermal performance of the proposed wet pad assisted air-cooled battery thermal management system is improved compared to a traditional one.
Keywords Electric vehicles, Battery thermal management, Forced air cooling, Direct evaporative cooling