Abstract
<jats:p>An experimental study of heat transfer during condensation of ozone-safe zeotropic refrigerant R407C on smooth and longitudinally finned surfaces was conducted. The effect of temperature glide on the intensity of heat transfer during condensation was studied at various operating parameters: saturation pressure of 0.95–1.5 MPa, saturation temperature of +14.5...+22.5 °C nd heat flux density relative to the entire finned surface of q = 960–13361.57 W/m². Local and average heat transfer coefficients for the fins, interfin and total finned surface, as well as the condensate film thickness were determined. The results were compared with the calculated data using the Nusselt formula. It was established that temperature glide significantly affects the efficiency of heat transfer and should be taken into account when calculating and designing condensers for zeotropic mixtures. It is noted that the obtained dependencies allow for the optimization of the designs of heat exchangers using R407C in the context of retrofitting and the development of new equipment.</jats:p>