Effects of Different Coolants on the Cooling Performance of an Impingement Microchannel Cold Plate

Increasing power densities due to the rise of Artificial Intelligence (AI), high-performance computing (HPC) and machine learning can lead to the increasing cost and complexity of thermal management in electronics devices. With very high specific heat and latent heat compared to air cooling, liquid cooling can be an alternative solution and currently an emerging technology in data center cooling. This paper describes experimental characterization of a liquid cooling cold plate in terms of thermal resistance and pressure drop. The liquid cold plate design incorporates impingement into a microchannel structure. Coolant enters the cold plate at the inlet then impinges down to the base of the cold plate at the trapezoidal groove. A copper block with a top surface area of 1 inch $\times 1$ inch was used to mimic the computer chip surface. Various coolants were used in this study including deionized water (100 % water), a mixture of coolants (10, 20, 30 % ethylene glycol +90,80, 70% water) and dielectric coolant3M Novec 7000 HFE. A comparison in the thermal and hydraulic performance of these coolants was presented. Effects of flow rate and coolant inlet temperature on both thermal resistance and pressure drop were studied in detail.