- With the continued decrease in size and subsequent increase in power of computer processors, thermal management in electronics is becoming more important than ever before. The chip heat densities are reaching new peaks (> 100 W cm-2) that current cooling methods are not able to keep up with. However, some preliminary data suggests that supercritical carbon dioxide (sCO2) has the potential to yield lower heat-sink temperatures at very high heat fluxes (> 200 W cm-2) with less energy consumption compared to single-phase liquid cooling. Previous research with supercritical fluids has focused on heat fluxes that are much less than what is required for electronics cooling applications and macroscale test sections. Additionally, existing convection heat transfer correlations do not account for the drastic changes in thermophysical properties near the pseudo-critical point.
In this study, heat fluxes that are more appropriate for electronics applications were achieved while using sCO2 as the working fluid to remove the high heat densities. The heat transfer performance was characterized in non-circular microscale geometries (Dh = 743.6 μm) with a wide range of parameters, including heat flux (40 ≤ q” ≤ 60 W cm-2) and mass flux (500 ≤ G ≤ 1000 kg m-2 s-1). Utilizing existing literature correlations for comparison, a MAPE of approximately 40% was achieved indicating that better supercritical fluid correlations are needed. The methodology and results developed in this paper can be employed in future applications that involve supercritical working fluids.
Key Words: Supercritical, heat transfer, experiments, electronics cooling