부산대학교 도서관

Current study presents an experimental analysis of nucleate pool boiling on the GNP/Ni-TiO2 (GNP-graphene nano particle) nano-composite coated copper surfaces. In order to produce the microporous surfaces, a two-step electro-deposition process is used. This deposition results in the formation of a modified surface structure, and various surface morphological characteristics of this modified structure, like wettability, roughness and surface structure are studied. The results reveal an improvement in CHF (critical heat flux) and BHTC (boiling heat transfer coefficient) in case of GNP/Ni-TiO2 coated surfaces. The main elements influencing the improved heat transfer of the GNP/Ni-TiO2nano-composite coating are its increased wettability, roughness, and high thermal conductivity. The SNCCC (superhydrophilic nano-composite coated copper) surfaces have the maximum BHTC of 97.52 (kW/m2K) and CHF of 2043 (kW/m2), which are 93% and 88% higher than the base Cu surfaces respectively. Here, it is analysed how the performance of SNCCC surfaces are enhanced by the impact of different parameters, like the roughness of the surface and wettability. The bubble characteristics at the time of boiling is noticed using a high-speed camera, and several factors such as nucleation site density, bubble departure diameter, and bubble emission frequency are statistically studied for SNCCC surfaces.