Jet impingement heat transfer using a Field's alloy nanoparticle - HFE7100 slurry

An experimental study was performed to investigate jet impingement heat transfer of HFE7100 dielectric liquid with metallic phase change materials (Field's alloy) in nanometer particulate form (nano PCM). A simple method was used to prevent the precipitation of Field's alloy nanoparticles in a HFE7100 suspension by surface modification with silane monolayers. The optical transmittance of the nanoparticle suspension was monitored by a portable spectrometer and there was no significant change in optical transmittance over time. The nano PCM particle suspension impinges on a heated surface and absorbs heat by phase change process from solid to liquid phase coupled with the evaporation of HFE7100. The present study shows that the mass fraction of nanoparticles plays an insignificant role in pressure drop but an important role on heat transfer performance. The high-heat-flux removal capability has been demonstrated by repeated closed loop test. Our results show that slurries with 30% particle mass fraction can improve the average heat transfer coefficient by 70% when compared to pure HFE7100 in the temperature range of 62-66 °C.