LAUSR

Abstract A new refrigerant-based closed cycle battery cooling system for electric and hybrid vehicles under test and actual drive cycles is introduced, and its performance is investigated. The refrigerant-based system offers the potential to eliminate the need of mechanical refrigeration, increase the life cycle of the batteries, reduce the charging time, and to reduce the size of the battery thermal management system. The refrigerant cooling system has the batteries submerged in a saturated liquid pool of refrigerant R134a, which cools the batteries and evaporates. The R134a vapor is condensed and returned to the supply pool. Two battery spacing variation are considered to evaluate the performance of the cooling system. The performances of the proposed system at the various operating parameters considered are comparatively evaluated through three dimensional modeling and simulation. The compact considered design was found to be able to provide performance similar to the large spaced design, leading to the conclusion that the spacing between the batteries within the considered variations has an effect on the performance of the refrigerant based system that can be neglected. The present results show that the compact design of the refrigerant based thermal management system can maintain the battery maximum temperature under 35 °C for and with a temperature variation within 4 °C for the case where 80% of the battery is submerged in the pool. The results from the Artemis realistic motorway cycle showed that the proposed system achieved a maximum temperature variations within 2 °C and under a maximum temperature of 31.5 °C, respectively.