Simulation and Experimental Investigation of Single and Two-phase Cold Plate Using HFE-7200 with Discrete Heat Sources

In this paper, the single and two-phase thermohy-draulic performances of a pin-fin cold plate that uses HFE-7200 dielectric fluid are numerically and experimentally investigated. The cold plate is designed to manage the heterogeneous heat losses by a 25-kW electric motor converter. The converter power losses are represented by background and hotspot heat sources. The background heat fluxes are 2.5 W/cm ² and 5 W/cm ² generating a constant 420 Watts, and the hotspot heat fluxes are varied between 100 to 1,000 W/cm ² . The effect of the upstream hotspots on the downstream temperatures/hotspots is studied for a channel flow configuration cold plate. Full-scale single-phase conjugate computational fluid dynamics and heat transfer (CFD/HT) simulations are used to ensure the uniformity of the temperature and flow distributions of the designed cold plate. The cold plate is tested at inlet temperatures of 25 °C. Visualization of the flow using a digital and a high-speed camera shows the transition from single-phase forced convection cooling to two-phase nucleate boiling at local hotspots.