Heat Transfer in Nucleate Boiling of Oil-freon Rll3 Mixtures : 1st Report, Effect of Oil Concentration on Boiling Heat Transfer

抄録

This paper describes heat transfer studies in nucleate boiling of polyolester oil and freon R113 binary mixtures done to obtain design data on heat transfer performance characteristics of an evaporator. Pool boiling experiments were performed around horizontal straight heater pin at atmospheric pressure, heat flux was changed from 0 to 70 kW/m², and mixture oil concentrations from 0 to 100 weight %. These data were compared with published studies on oil-freon binary mixtures. The oil concentration influenced the heat transfer coefficient of oil-freon R113 mixtures ; with lage oil concentrations, a remarkable reduction in heat transfer occurred. Then based on the data, an empirical correlation for the heat transfer coefficient of oil-freon R113 mixtures was obtained. The correlation included terms for wall superheating of freon R113, oil temperature difference, and oil mole fraction. Comparisons were made between experimental and calculated results. The proposed correlation was found valid for the prediction of heat transfer coefficients of oil-freon R113 mixtures.