Linear Layer Thermal Analysis of Lithium-Ion Battery Cooling System for Electric Vehicles

Abstract

Lithium-ion power battery has become one of the main power sources for electric vehicles and hybrid electric vehicles because of superior performance compared with other power sources. In order to ensure the safety and improve the performance, the maximum operating temperature and local temperature difference of batteries must be maintained in an appropriate range. In this thesis we are experimenting the cooling system of the Li-ion batteries combined with a phase change material and heat pipes to control abnormal heat emissions to improve the battery performance and efficiency. The hybrid cooling system solid model is prepared in CREO software and the CFD analysis is evaluated in the ANSYS software. The hybrid cooling system model designed with different types of heat pipe designs and is analyzed with different mass flow rates (30& 50L/min). The comparison is done among three kinds of the hybrid cooling system (combining the heat pipes and PCM) with numerical analysis of the heat balance and thermal analysis. In this thesis the pressure, velocity, heat transfer coefficient, mass flow rate and heat transfer rate for the different designs of heat pipe and different mass flow inlets is determined in CFD analysis. Two types of phase change materials (RT50 & Li Fe PO4) are used to determine the temperature distribution and heat flux. The results of the analysis compare the heat transfer rate of the four different kinds of the cooling system design.