Experimental investigation in pool boiling heat transfer of ternary mixture and heat transfer correlation

Heat transfer coefficients in nucleate boiling on a smooth flat surface were measured for pure fluids, their binary and ternary mixtures under the saturated conditions at 0.6 MPa for a wide range of heat flux and mixture concentration. Refrigerants, R-134a, R-142b and R-123 were used to make up binary and ternary mixtures. Compared to the ideal heat transfer coefficients calculated from a mole fraction average of the wall superheats of pure components, both binary and ternary mixtures showed lower heat transfer coefficients. This reduction was more pronounced as heat flux was increased. The data of binary mixtures were well reproduced by Thome-Shakir and Fujita-Tsutsui correlations. For ternary mixtures, dimensionless heat transfer coefficients plotted on the concentration triangle were very similar to the contour map of boiling range. This similarity suggested the boiling range is an essential parameter to account for heat transfer reduction of ternary mixtures. Fujita-Tsutsui correlation was found applicable to ternary mixtures with a reasonable success. (C) 2002 Elsevier Science Inc. All rights reserved.