INVESTIGATIONS OF POOL BOILING HEAT-TRANSFER OF BINARY REFRIGERANT MIXTURES

Pool boiling data for binary mixtures of R-22/R-124 on plain tubes are reported at reduced pressures of 0.1, 0.15, and 0.2. Significant redu ctions of heat transfer coefficients for mixtures are found as compare d to pure refrigerant, and the reduction of heat transfer coefficient is especially pronounced in the vicinity of the pore component. This p henomenon is strongly related to the nonlinear variation of physical p roperties of liquid viscosity and latent heat of the mixtures. The ava ilable empirical and semiempirical correlations developed for mixtures are compared with the present data. In addition, a correlation based on the present R-22/R-124 experimental data is proposed. This correlat ion not only predicts the deterioration of heat transfer coefficients for the present data with success but also predicts the experimental d ata from other investigators with reasonably good accuracy.