Experimental investigation on thermal performance of a pumped two‐phase battery cooling system using mini‐channel cold plate

Abstract

This study presents an experimental investigation on a pumped two-phase battery cooling system using R1233zd(E) as the refrigerant. The thermodynamic cycle of the system, together with the heat transfer and pressure drop characteristics of the mini-channel cold plate, were analyzed under different conditions. Results showed that the pressure rise of the pump was increased under higher heat flux and mass flux, and the overall system pressure was elevated when the coolant bath temperature was raised. The effects of the mass flux on the overall heat transfer coefficient of the cold plate were different under various heat fluxes, while pressure loss of the cold plate showed a dramatic rise after the heat flux was over 2 W·cm−2. The average temperature of the cold plate was generally decreased with the increasing mass flux, while the maximum temperature difference was nearly constant when the heat transfer was dominated by single-phase forced convection. However, the maximum temperature difference could be lowered after flow boiling became dominant. In addition, the local heat transfer characteristics for different channels and the temperature uniformity in the cold plate were investigated. It was found that the local temperature was increased and then stabilized along the flow direction, while the local heat transfer coefficient was increased monotonously. Meanwhile, lower local temperature and higher heat transfer coefficient were found in the upper channel for the intensive boiling with lower mass flux which compared to the middle channel. Novelty Statement This study investigated the performance of a pumped two-phase battery cooling system using mini-channel plate under higher heat flux and discussed the reasons for wall temperature variation and temperature uniformity under different heat transfer mechanisms.