Boiling Heat Transfer of R32, CO2 and R290 inside Horizontal Minichannel

This study demonstrated two phase flow boiling heat transfer coefficient of R32 (difluoromethane), CO2 (carbon dioxide) and R290 (propane) in minichannel. The experimental data were conducted in horizontal stainless steel tubes with the inner diameter of 1.5 mm. The testing conditions were performed with the mass fluxes range from 150 to 500 kg/m2s, the heat fluxes from 5 to 20 kW/m2, the saturation temperature of 10 degrees C and the vapor quality from 0.1 to dry-out. The effects of mass flux and heat flux on the heat transfer coefficient were analyzed. The experimental data were also compared with some well-known heat transfer coefficient correlations. (C) 2017 The Authors. Published by Elsevier Ltd.