Forced Convective Boiling of Nonazeotropic Refrigerant Mixtures of R22 and R114 Inside a Horizontal Tube

Abstract

Experimental results of forced convective boiling of nonazeotropic refrigerant mixtures of R22 and R114 inside a horizontal tube with internal spiral grooves are presented. Pure refrigerants R22 and R114 and three kinds of their mixtures containing about 25, 50 and 75 mol%R114 are tested in the ranges of mass velocity of 77 to 347 kg/(m2s) and of pressure of 0.6 to 7 bar. The axial distributions of refrigerant temperature and heat transfer coefficient for mixed refrigerants depend on the concentration, while those for pure refrigerants of R22 and R114 show similar behavior. An empirical correlation concerning the heat transfer coefficient of pure and mixed refrigerants is proposed as a function of the boiling number, Lockhart-Martinelli parameter and liquid heat transfer coefficient for a smooth tube. © 1988, The Japan Society of Mechanical Engineers. All rights reserved.