Thermal management of refrigerant direct cooling and mass flow control strategies for multiple discrete heat sources system

Challenges for controlling heat dissipation and temperature uniformity are presented by variations of heat source conditions in the power battery thermal management system. The efficiency of cooling systems can be enhanced by investigating the impact of heat source side variations on direct cooling performance for configurations with multi-point discrete heat sources. This study examines the effects of baseline heat sources arrangement, hotspot heat sources location and flow direction configuration on the direct cooling effect. The findings reveal that the influence of heat source arrangement on the direct cooling effect is similar under the same total heat generation, while the overall suitable operating mass flow rate interval range is lengthened with the increment of total heat generation. Furthermore, as the hotspot heat sources from outlet to inlet, the suitable operating mass flow rate interval of system changes from 0.164–0.207 g·s⁻¹ to a broader range of 0.119–0.334 g·s⁻¹, with a maximum reduced working heat source temperature difference of 2.87 K, and the temperature uniformity of heat sources is improved. Then, the suitable operating mass flow rate interval can be extended to 3.63 times by optimizing the flow direction. The investigation on direct cooling obtained the optimal mass flow rate interval and the temperature uniformity for different heat source arrangements and hotspot heat source positions, which can be optimized by counter-flow distribution.