Condensation of Refrigerant Mixtures R22+R114 Inside a Horizontal Tube

Experimental study of the condensation of pure and mixed refrigerants of R22 and R114 inside a spirally grooved horizontal tube is carried out for a tube-in-tube counter flow type condenser in the ranges of 3~21 bar of pressure and 26~70 kg/h of mass flow rate. Axial distributions of refrigerant, tube wall and cooling water temperatures, wall heat flux and vapour quality are graphically shown and circumferential distribution of tube wall temperature is also shown. The characteristic of the local Nusselt number depends on the molar fraction, while the average Nusselt number can be correlated well by an equation, which is modified from a previously established equation for pure refrigerants inside a smooth tube.