AN EXPERIMENTAL AND MODELING STUDY ON DEVICE- AND SYSTEM-LEVEL TWO-PHASE COOLING FOR HIGH-HEAT-FLUX APPLICATION

A multi-microchannel two-phase cold plate made of copper is tested for temperature rise and flow resistance to verify its feasibility for heat dissipation in high-heat-flux devices such as GPU, as well as programmed with EES (Engineering Equation Solver) to predict its temperature profile and pressure drop across the device. The microchannel cold plate has a channel height of 3mm, a channel width of 0.3mm, a fin thickness of 0.2mm, a total width of 50mm, and a total length of 60mm. The 3D model of the cold plate and heat source was imported into COMSOL to complete the three dimensional heat conduction analysis based on the convective flux boundary conditions calculated with EES. Through correlation-based EES coding for thermal and hydraulic behaviors in the cold plate, the heat transfer and flow resistance have been predicted very well. Among the components of the overall pressure drop across the cold plate, the local two phase flow resistances, especially the abrupt bend and restriction of the outlet, play an extremely vital role. Moreover, the adiabatic pressure drop between the microchannel cold plate and condenser is proved to be a key factor that affects the working pressure or saturation fluid temperature in the cold plate, which in turn determines the temperature rise of the cold plate over the atmosphere. This study provides not only a feasibility analysis for the high-heat-flux cooling solution, but also a reliable and easy-to-use tool for predicting multi-microchannel cooling device and system.