Effect of Oil on Condensation in a Microfinned Tube

Sweeney, K.A.; Chato, J.C.; Ponchner, M.; Rhines, N.L.

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https://hdl.handle.net/2142/11126 Copy

Description

Title

Effect of Oil on Condensation in a Microfinned Tube

Author(s)

• Sweeney, K.A.
• Chato, J.C.
• Ponchner, M.
• Rhines, N.L.

Issue Date

1995-10

Keyword(s)

• geometric variables
• R-22 alternatives

Abstract

The effects of an ester oil, in concentrations up to 5% by mass, on the behavior of R -134a condensing in a microfinned tube with an 18° helix angle were studied experimentally. The flow patterns were only minimally affected with some indication that a shift from wavy towards annular flow may be caused by the oil at the low mass fluxes. The heat transfer followed similar trends due to the presence of oil in a microfinned tube as those that occurred in a smooth tube. At low qualities there was no significant effect but, as quality increased, the heat transfer in the oil carrying refrigerant began to be depressed compared to the pure refrigerant. At some high quality the heat transfer reached a peak value. Beyond this quality the heat transfer decreased rather rapidly. The oil did not seem to have a large effect on the pressure drop in the test section. Only at the highest qualities were slight increases. measured at increased oil concentrations.

Publisher

Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign.

Series/Report Name or Number

Air Conditioning and Refrigeration Center TR-87

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/11126

Sponsor(s)/Grant Number(s)

Air Conditioning and Refrigeration Center Project 37

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