An Experimental Study of Refrigerant Desorption from a Refrigerant-Oil Mixture Subjected to Rapid Depressurization

摘要

This paper deals with the experimental assessment of refrigerant desorption leading to foam formation in R-rn134a/POE oil mixtures undergoing controlled depressurization. An experimental apparatus was designed andrnconstructed to allow measurements of pressure drop rate, foam height and refrigerant gas mass flux resulting fromrndecompression and desorption from a saturated liquid mixture. High-speed video recording of the phenomenonrnenabled the identification of three main periods during the depressurization/foaming process, namely,rndepressurization without cavitation, vapor flashing and rapid foam growth, and foam layer decay. The experimentalrnresults for the maximum foam height, foam lifetime and liquid supersaturation during desorption were explored as arnfunction of the overall initial refrigerant mass fraction and physical properties of the liquid phase.