Refrigerant/Lubricant Mixture Boiling Heat Transfer Research at NIST
Mark A. Kedzierski
This paper overviews the boiling heat transfer research of the recent few years at NIST (National Institute of Standards and Technology) on refrigerant/lubricant mixtures. The aim of the research was to fundamentally understand the effects of lubricant properties and bubble parameters on the heat transfer performance. The magnitude of the effect of lubricant viscosity, miscibility, and concentration on the heat transfer has been quantified. The mechanistic cause of each effect was given based on new theoretical interpretation and/or one from the literature. The NIST research illustrates that large improvements over pure R134a heat transfer can be obtained for R134a/lubricant mixtures with small lubricant mass fraction, high lubricant viscosity, and a large critical solution temperature (CST). A mechanistic explanation for the observed R134a/lubricant boiling is provided. A fluorescence measurement technique is currently under development with the purpose of unlocking the mechanisms of the lubricant excess layer.
Proceedings of Future Trends in Mechanical Engineering, 16th National Convention of Mechanical Engineers and All India Seminar.
September 29-30, 2000
National Convention of Mechanical Engineers and All India Seminar on Future Trends in Mechanical Engineering
Refrigerant/Lubricant Mixture Boiling Heat Transfer Research at NIST, Proceedings of Future Trends in Mechanical Engineering, 16th National Convention of Mechanical Engineers and All India Seminar., Roorkee, IN, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=860829
(Accessed June 1, 2023)