Experimental Investigation of a Liquid Metal Mini-Channel Cooling System Coupled with Liquid Carbon Dioxide (CO2) Throttling Refrigeration

Liquid metal cooling systems for high heat flux devices typically employ air or water cooling as the heat dissipation section to reject heat to the environment, but these conventional approaches face challenges in efficiency and adaptability.This study proposes the use of liquid carbon dioxide (CO 2 ) throttling refrigeration technology as the heat dissipation section to couple with a liquid metal cooling system, thereby achieving a compact and highly adaptable cooling system.The dynamic and heat transfer characteristics of the system were thoroughly investigated through experiments.The experimental results demonstrated that the convective heat transfer coefficients consistently exceeded 90000 W/(m 2 K).Under a heat flux of 206 W/cm 2 , the temperature rise of the heat source surface relative to the inlet fluid was less than 50 C.By adjusting the control temperature of the solenoid valve, the heat source surface temperature can be more flexibly regulated.Based on the experimental data, a heat transfer correlation was developed for liquid metal mini-channel heat sinks operating at low to moderate Peclet numbers.The proposed two-stage cooling system combining liquid metal and liquid CO 2 offers a promising compact and high-performance solution for complex thermal management challenges, particularly in scenarios with variable heat flux densities and ambient temperatures.