Heat transfer of gas-water two-phase flow in microgap

Thermal management faces a challenge in high power and density packaging. Microchannel is a promising technique for heat transfer in minimized devices. However, the high power chip has a flat structure to need a microgap for heat transfer in efficiency. This paper studied the heat transfer with non-boiling in microgap with gas-water two-phase flow based on the phenomenological theory. The input heat flux was fixed and the volume flow rates of nitrogen and DI water had a widely values. Six spots of wall temperature had been monitored, and it was found the outlet areas had higher wall temperature than those at inlet areas. The wall temperature decreased with the increasing of volume flow rate of DI water, or with the increasing of volume flow rate. The phenomenological equation had been established for the wall temperature including two components, which were a negative power exponent function and a negative logarithm function governed by the volume flow rates of DI water and nitrogen, respectively. Compared with the liquid component, the gas component has a stronger effect on the wall temperature equation, and it was attributed to the gas fraction playing a more important role in heat transfer with gas-water two-phase flow. Q_N2=512 sccm and Q_water=128 sccm were the best parameters for heat transfer in microgap in experiments.