Heat Transfer and Pressure Drop During Condensation of Refrigerant 134a in an Axially Grooved Tube

Graham, D.M.; Chato, J.C.; Newell, T.A.

Permalink

https://hdl.handle.net/2142/11588 Copy

Description

Title

Heat Transfer and Pressure Drop During Condensation of Refrigerant 134a in an Axially Grooved Tube

Author(s)

• Graham, D.M.
• Chato, J.C.
• Newell, T.A.

Issue Date

1997-03

Keyword(s)

• void fraction
• refrigerant condensation and evaporation

Abstract

"R134a condensation experiments have been petfonned over a mass flux range of 75 to 450 kg/m2-s (55 to 330 klbm/ft2-hr) in an 8.91 rom (0.351"") inside diameter, axially grooved, microfin tube. At 75 kg/m2-s (55 klbm/ft2-hr), the axially grooved tube petfonns marginally better than a smooth tube, but worse than a similarly grooved tube with an 18 degree helix angle over a broad range of refrigerant qualities. Mass fluxes at 150 kg/m2-s (110 klbm/ft2-hr) and greater show broad quality ranges in which the axially grooved tube petfonns significantly better than both smooth and helically grooved tubes. Examination of a Froude rate parameter indicates that the axially grooved tube is able to maintain an annular film flow characteristic that results in more efficient heat transfer. Pressure drop characteristics of the axially grooved tube are similar to those found in an 18 degree helix angle tube."

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-114

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/11588

Sponsor(s)/Grant Number(s)

Air Conditioning and Refrigeration Project 74

Owning Collections