Effect of Concentration on R134a/Al2O3 Nanolubricant Mixture Boiling on a Reentrant Cavity Surface

Published

November 23, 2014

Author(s)

Mark A. Kedzierski

Abstract

This paper quantifies the influence of Al2O3 nanoparticles on the pool boiling performance of R134a/polyolester mixtures on a Turbo-BII-HP boiling surface. Nanolubricants with 10 nm diameter Al2O3 nanoparticles of various volume fractions (1.6 %, 2.3 %, and 5.1 %) in the base polyolester lubricant were mixed with R134a at two different mass fractions (0.5 % and 1 %). The study showed that nanolubricants can improve R134a boiling on a reentrant cavity surface as long as the nanoparticles remain well dispersed in the lubricant and are at sufficiently large concentration. For example, three of the refrigerant/nanolubricant mixtures with the smallest nanoparticle mass fraction exhibited average enhancements over the entire heat flux range of approximately 10 %. However, when the nanoparticle mass fraction was increased to a point that likely encouraged agglomeration, an average heat transfer degradation of approximately 14 % resulted. An existing model was used to predict the boiling.

Citation

International Journal of Refrigeration

Pub Type

Journals

Keywords

additives, aluminum oxide, boiling, enhanced heat transfer, nanolubricant, nanotechnology, refrigerants, refrigerant/lubricant mixtures, structured surface

Citation

Kedzierski, M. (2014), Effect of Concentration on R134a/Al2O3 Nanolubricant Mixture Boiling on a Reentrant Cavity Surface, International Journal of Refrigeration (Accessed April 18, 2024)