Experimental Study on Pump-driven Refrigerant Two-phase Cold-plate Cooling System

The miniaturization and performance improvement of components continuously increase the power of electronic devices. Superior heat-dissipation performance is important for the reliability of electronic devices. In this study, an experimental pump-driven refrigerant two-phase cold-plate-cooling system was developed. Four two-phase cold plates with different materials (Cu and Al) and channel heights (10 mm and 15 mm) were designed and processed. The heat-transfer performance of the cold plates, together with their flow resistance characteristics, pump power under different heat fluxes (4.4-22.2 W/cm²), refrigerant cooling capacities (3-11 kW), and heat source positions were studied. The results indicated that the heat-transfer performance of the two-phase cold plate was superior. The maximum heat transfer coefficient was 26 kW/(m²·℃) when dealing with a concentrated heat source with a heat dissipation of 1000 W and a heat flux of 22.2 W/cm². The temperature difference between the heat source surface and the refrigerant was less than 15 ℃ when the total pressure drop of the system was less than 20 kPa and the power consumption of the refrigerant pump was less than 20 W. A natural cold source can be used for heat dissipation to achieve energy savings. The heat transfer characteristics of the two-phase cold plate can be described by the fin efficiency correlation and the Kandlikar heat transfer correlation. The deviation between the temperature difference calculated by the theoretical formula and the measured value was less than 1 ℃. The results of this study can guide the design of cold-plate channels.