Temperature Control Characteristics of Automotive Power Battery Based on R-1233zd(E)’s Flowing Phase Change Heat Transfer 2018-01-1191

Li-ion power battery is the core component of the electric vehicle power system, and the battery temperature will increase because of the electrochemical reaction of the Li-ion battery. The heat accumulates inside of the battery, which can degrade the working performance of the power battery and shorten the battery cycle life. At present, the wind cooling technology is relatively mature. However, it cannot achieve ideal heat dissipation effect under the working conditions of the high-power or high ambient temperature. In this research, the battery thermal management is carried out by the characteristics of the working fluid’s flowing phase change heat transfer. The phase change working fluid is R-1233zd(E) which is a kind of environmentally friendly liquid with nonconductive and nonflammable. It can achieve the purpose of controlling the battery’s temperature using the characteristics of isothermal heat absorption under different gas phase rate of phase change working fluid. In this paper, the mathematical model of heat generation about the lithium iron phosphate battery is established by analyzing the battery heat generation mechanism. Then, the mathematical model of the R-1233zd(E) phase change heat transfer is established for researching the heat-transfer characteristics of battery under different discharge rate conditions. Finally, design a battery heat dissipation system based on the R-1233zd(E) phase change heat transfer and perform the temperature control experiment of the battery under different discharge rate. The results show that the temperature changes on the surface of the battery can be controlled within 2 degrees Celsius by the R-1233zd(E)’s flowing phase change heat transfer. Compared with wind cooling, this way can make the battery’s surface temperature fluctuation smaller.