THERMAL MANAGEMENT OF EV BATTERY USING LIQUID COLD PLATE

Abstract

The number of hybrid electric vehicles (HEVs) and pure electric cars (EVs) has increased significantly in recent years in response to the scarcity of fossil fuels and the desire to lower vehicle exhaust emissions. With the advancement of electric car technology, a lot of attention has been paid to battery heat management. It is important to conserve energy and is crucial to keep the battery's temperature within a reasonable range. An operating temperature of 25-40 °C is recommended for safe operating condition of Li-ion battery. In this view in the present study, three dimensional steady state numerical simulations are conducted for battery thermal management system using in-house liquid cold plate for cooling a battery pack. The in-house liquid cold plate consists of series of mini channels followed by a mixing chamber. The mixing chamber promotes uniformity and increment in heat transfer by bringing coolant at a common temperature before passing it to next series of mini channels. The heat and flow investigations are conducted using ANSYS ICEPAK. A Li-ion battery pack with 2´16 cells are cooled by inhouse liquid cold plate from two of its sides. Water at uniform velocity and at 303.15 K is considered as the coolant. The total battery pack power capacity is 1281.28 W which corresponds to total heat loss at 5C of charging. Several flow and geometrical parameters such as Reynolds number of coolant, width of mini channels, spacing of mixing chamber etc are also studied in the present work. The simulations are validated with existing experimental data in open literature. Numerical investigations using additional cold plate in between the rows of two batteries is also done. The in house mini channel configurations prove to be an efficient design for bringing better uniformity in temperature over exiting liquid cold plate designs.