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ISSN Online: 2377-424X

ISBN Print: 0-85295-345-3

International Heat Transfer Conference 10
August, 14-18, 1994, Brighton, UK

THE EFFECT OF ESTER-OILS ON HEAT TRANSFER DURING EVAPORATION OF REFRIGERANT HFC134A

Get access (open in a dialog) DOI: 10.1615/IHTC10.1440
pages 551-556

Аннотация

Local convective flow-boiling heat-transfer coefficients were measured for CFC12, CFC113, HFC134a and HFC134a mixed with an ester-oil inside a horizontal smooth tube. The experimental parameters covered a system averaged oil concentration of 0-4.7%, a vapour quality of 0.1-0.75, a heat flux of 15-45 kW/m2 and a mass flux range of 257-613 kg/m2s. Comparisons between the measured heat-transfer coefficients of pure refrigerants and published models currently favoured in the refrigeration industry were performed. The HFC134a-ester oil heat-transfer data were compared with existing correlations specifically designed for refrigerant-oil mixtures. None of them appeared to be satisfactory. A tentative correlation for the oil-refrigerant data based on a mechanistic approach is suggested.