Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

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



Mark A. Kedzierski


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.
International Journal of Refrigeration


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


Kedzierski, M. (2014), Effect of Concentration on R134a/Al2O3 Nanolubricant Mixture Boiling on a Reentrant Cavity Surface, International Journal of Refrigeration (Accessed April 16, 2024)
Created November 23, 2014, Updated February 19, 2017