Experimental pool boiling heat transfer analysis through novel ZnO-coated Cu (Cu@ZnO nanoparticle) hybrid nanofluid boiling on the fin tops of different microchannels

Open microchannels and micro/nanoporous coatings by nanofluid boiling have been used separately by earlier researchers to improve heat transfer during pool boiling. The combined impact of these factors is examined in this work by novel ZnO-coated Cu (Cu@ZnO) hybrid nanofluid boiling on the apex of microchannels' fins, resulting in development of micro/nanoporous coatings on the apex of microchannels' fins. The Cu@ZnO hybrid nanoparticles were prepared by optimal spark discharging in liquid nitrogen. The next phase involves dispersing the developed nanoparticles in DI water as the base fluid to achieve stable nanofluids. This article reports on the impact of microchannel geometry on the efficiency of heat transmission for water and hybrid nanofluid boiling on copper chips. A higher concentration of nanofluid with microchannel configuration enhanced the CHF and HTC throughout the pool boiling experiment. The highest increases in HTC and CHF were reported to be 287.57% and 123.60%, respectively, for 0.1% hybrid nanofluid on 300-mu m microchannel. The mechanisms of bubble formation and heat transport are changed when nucleation occurs mostly on the fin tops. The present study's theory is founded on the improved rewetting routes offered by microchannels and the extra nucleation spots offered by porous layers, both of which operate in concert to improve boiling behaviour. A microconvective process wherein highly localized liquid circulating currents are created in the microchannels by bubbles emerging from the tops of the fins. Additionally, a conceptual framework based on liquid microcirculation is suggested.