Evaporating heat transfer of R-600a: An experimental study of the major parameters affecting heat-transfer

In this paper, heat transfer characteristics of the hydrocarbon refrigerant R-600a during flow boiling inside horizontal smooth tube are investigated. For this purpose an experimental set up was constructed The test section was a plain copper tube with outside diameter of 9.52 mm and wall thickness of 0.63 mm. The experimental tests are carried out varying: (i) the refrigerant mass fluxes within the range of 70–350 kg/m^2s; (ii) the vapor qualities within the range of 0.1– 0.9. The Results indicate that the average flow boiling heat transfer coefficient increased as the mass velocity increased in the fixed vapor quality. Moreover, the heat transfer coefficient increased by the increase of vapor quality as the mass velocity was fixed. Present study experimental data for flow boiling heat transfer coefficient was compared with some existing correlations in order to find out which correlation could predict the convective boiling heat transfer characteristics of HC-R600-a. The results indicate that Gungor–Winterton correlation had the best consistency with present study experimental data for HC-R-600-a refrigerant.

کلیدواژه ها:

Convective boiling ، Heat transfer ، R-600a hydro carbons