Intube condensation with refrigerants

A new experimental apparatus has recently been set up at the Dipartimento di Fisica Tecnica of the University of Padova. Condensation tests for several refrigerants were conducted inside a smooth tube by directly measuring the wall temperature in the test section. The experimental runs to measure the heat transfer coefficients were carried out at an average saturation temperature of 40°C at mass velocities ranging from 100 to 750 kg/(m2 s), over the entire vapour quality range. The refrigerants used in the tests include HCFC 22 and HFC 134a. The experimental data was compared to the best known correlations for heat transfer prediction during condensation of refrigerants and showed good agreement. Condensation tests were also conducted on nearly azeotropic mixtures (R-410A) and zeotropic mixtures (R-407C, R-125/236ea (45/55)). Pressure drop data is also collected for the same refrigerants. Experimental pressure losses and comparisons with the models are shown here for R-22.