Share

IIR document

Experimental analysis of refrigerant mixing in lubricant oil.

Author(s) : ORTOLAN M., BARBOSA J. Jr

Summary

Refrigerant absorption and mixing in lubricant oil are important in compressor and system design. Experimental work is reported on absorption of refrigerant vapour through the top interface of an initially stagnant layer of pure lubricant oil. Depending on the refrigerant-oil pair, the liquid refrigerant is heavier than the oil and mixing is enhanced due to natural mass convection. This behaviour is typical of HFC refrigerants such as R-134a. In contrast, in systems where the liquid refrigerant is less dense than the oil (for example, HC refrigerants, like R-600a and R-290) liquid density instability near the interface does not occur and absorption takes place by molecular diffusion alone. A test rig consisting of a transparent test section through which absorption is observed was specially constructed for these experiments. During each experimental run, the overall mass of refrigerant in the test section was kept constant and, as a result, the pressure decreased with time. Tests were conducted for R-134a and R-600a with three POE oils of distinct viscosity grades and the effect of the initial depth of the oil layer (aspect ratio) on the velocity field and on the refrigerant absorption rate (i.e., pressure change rate) was assessed.

Available documents

Format PDF

Pages: 2006-5

Available

  • Public price

    20 €

  • Member price*

    Free

* Best rate depending on membership category (see the detailed benefits of individual and corporate memberships).

Details

  • Original title: Experimental analysis of refrigerant mixing in lubricant oil.
  • Record ID : 2007-0631
  • Languages: English
  • Source: Compressors 2006: 6th International Conference on Compressors and Coolants
  • Publication date: 2006/09/27

Links


See other articles from the proceedings (48)
See the conference proceedings

Indexing