Experimental investigations on the performance of mini-channel evaporator refrigeration system for thermal management of power batteries.

• Refrigeration system with evaporator mini-channel structure was developed for power batteries. • The effects of refrigerant charge, OTV and heating power were examined. • For OTV from 41.9% to 79.1%, the heat transfer coefficient first increases and then decreases slightly. • Temperature of battery module with heating power of 100 W-200 W can be restrained within 10.8°C -45.7°C by adjusting OTV. The vapor compression refrigeration system possesses excellent thermal performance owing to two phase boiling with large latent heat, which can be a promising option for refrigerant cooling of battery modules. In this work, the battery thermal management equipped with a small-scale refrigeration system was built up, which primarily consisted of the mini-channel evaporator directly mounted with a battery module, compressor, throttle valve and fan-cooled condenser. The influencing factors such as the refrigerant charge, openness of throttling valve (OTV) and the heating power were examined experimentally. It is found that, with the increase in the refrigerant charge, the system coefficient of performance (COP) first increased and then decreased. When the heating power is between 100 W to 200 W, the temperature of the battery module could be controlled in a suitable range, namely 10°C-45°C, by adjusting the OTV within the range of 48.8%-72.1%. As the OTV increased, the heat transfer coefficient of the mini-channels first increased and then levelled off. As the heat power increased, the heat transfer coefficient of the mini-channels first increased and then decreased. The present study helps better understanding of thermal management using the vapor compression refrigeration system in the battery thermal management. [ABSTRACT FROM AUTHOR]