Experimental heat transfer coefficients during condensation of pure refrigerants on a commercial enhanced tube

This work experimentally investigates the effect of vapour shear on heat transfer during condensation of pure refrigerants on a commercial enhanced tube Hitachi Thermoexcel. Two different series of tests are taken: the first woth refrigerant 11, the second with refrigerants 113, with vapour pressure ranging from 100 to 190 kPa, average condensation temperature difference varying from 4 to 16°C an maximum vapour velocity from 1 to 38 m/s. The present experimental results are compared with analogous data prevously obtained by the Authors with integral-fin tubes and with the smooth tube trend.