Condensation of HFC-134a in an 18° Helix Angle Micro-Finned Tube

Ponchner, M.

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https://hdl.handle.net/2142/11018 Copy

Description

Title

Condensation of HFC-134a in an 18° Helix Angle Micro-Finned Tube

Author(s)

Ponchner, M.

Contributor(s)

• Chato, J.C.
• Sweeney, K.A.
• Shimon, R.L.
• Villaneuva, T.C.
• DeGuzman, N.M.
• Rhines, N.L.
• Allen, D.G.
• Hershberger, T.T.

Issue Date

1995-04

Keyword(s)

• R-22 alternatives
• refrigerant-side evaporation condensation studies

Abstract

"An experimental study of local condensation heat transfer and pressure drop characteristics of HFC-134a in an 18° helix angle, 0.375"" o.d. micro-finned tube was , conducted. The main goal of the study was to compare the heat transfer and pressure drop characteristics during condensation in the micro-finned tube to those in a smooth tube. In general, the heat transfer enhancement factors decreased as the refrigerant mass flux increased. The average enhancement factors ranged from 2.0 at a mass flux of 110 klbm/ft2-hr, to 1.4 at a mass flux of 330 klbm/ft2-hr. The enhancement factors also depended on the flow regime. In the wavy flow regime, high enhancement factors were usually observed, while in the annular flow regime, low enhancement factors were observed except ""at very high vapor qualities. The pressure drop penalty factors showed just a slight dependence on mass flux and vapor quality. In general, the penalty factors increased slightly as the mass flux increased and the vapor quality decreased The average penalty factors ranged from 1.19 to 1.26. A simple condenser model that combined the results of this study with pressure drop and heat transfer correlations from earlier studies was developed. The model was used to calculate the total length and refrigerant side pressure drop in a condenser for different operating conditions."

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-75

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/11018

Sponsor(s)/Grant Number(s)

Air Conditioning and Refrigeration Center Project 37

Owning Collections