CH-93-14-5 -- The Influence of Oil on Local Evaporation Heat Transfer Inside a Horizontal Microfin Tube

No previous study has been found on the local heat transfer coefficients with refrigerant-oil mixtures. Describes a study to obtain local heat transfer coefficients during evaporation of mixtures of R12 and 150 SUS naphthenic oil inside a microfin tube and to compare the results with the results of the oil-free condition. Describes the experimental programme. Presents and discusses the results. Finds that in general, compared to the pure refrigerant case, the addition of oil dramatically deteriorates the local heat transfer performance for most of the quality range, except at low quality.

KEYWORDS: heat transfer coefficient, heat flow, refrigerants, R12, lubricants, mixtures, oils, heat transfer fluids, tubes, evaporation, viscosity, performance, deteriorating, air conditioning, refrigeration, evaporators, comparing.