An experimental study on condensation and evaporation heat transfer and pressure drop in microfin copper tubes

This paper presents the experimental investigation to determine the condensation and evaporation heat transfer coefficients and pressure drops for the flow of R22 through internally grooved copper tubes namely B16-46 and D12-52. A series of experiments were conducted to evaluate the condensation and evaporation performances of the internally grooved copper tubes. Condensation tests were conducted at mass flux rates of 180 to 537 kg m^-2 s^-1 and the vapor qualities ranged from a nominal value of 83% at the test section inlet to 6% at the outlet. Evaporation tests were conducted at mass flux rates of 110 to 404 kg m^-2 s^-1 and the nominal vapor qualities at the inlet and outlet were 0 and 85%. For both the condensation and evaporation tests, the heat transfer coefficients and pressure drops are found to increase as the mass flux rate increases.