The effect of temperature difference (Tsat − Tcoolant) on condensation heat transfer coefficients inside horizontal tubes is investigated in detail. Condensation experiments are conducted on propane inside a 7.75 mm horizontal tube at four temperature differences between the test fluid and coolant at three mass fluxes and four saturation temperatures. The heat transfer coefficient is shown to increase with temperature difference, with this effect diminishing with larger temperature differences, and being most significant at higher saturation temperatures. Heat transfer coefficients at the low-reduced pressures (Pr = 0.25) corresponding to lower saturation temperatures (30 °C) are mostly unaffected by the temperature difference. Subcooling of the condensate is expected to increase heat transfer coefficients at the larger temperature differences. Flow visualization studies are used to explain the inadequacy of the Nusselt film theory for the conditions investigated. The underlying mechanisms are also used to explain why the correlations from the literature do not predict the observed trend, and a new correlation to account for the effect of temperature difference is developed.
Issue Section:
Evaporation, Boiling, and Condensation
References
1.
Nusselt
, W.
, 1916
, “The Surface Condensation of Water Vapor
,” Zetrschr. Ver. Deutch. Ing.
, 60
, pp. 541
–546
.2.
Le Fevre
, E.
, and Rose
, J.
, 1965
, “An Experimental Study of Heat Transfer by Dropwise Condensation
,” Int. J. Heat Mass Transfer
, 8
(8
), pp. 1117
–1133
.3.
Rose
, J.
, 2002
, “Dropwise Condensation Theory and Experiment: A Review
,” Proc. Inst. Mech. Eng., Part A
, 216
(2
), pp. 115
–128
.4.
Fernando
, P.
, Palm
, B.
, Ameel
, T.
, Lundqvist
, P.
, and Granryd
, E.
, 2008
, “A Minichannel Aluminium Tube Heat Exchanger—Part III: Condenser Performance With Propane
,” Int. J. Refrig.
, 31
(4
), pp. 696
–708
.5.
Gstöhl
, D.
, 2004
, “Heat Transfer and Flow Visualization of Falling Film Condensation on Tube Arrays With Plain and Enhanced Surfaces
,” Ph.D. thesis
, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.6.
Jung
, D.
, Chae
, S.
, Bae
, D.
, and Oho
, S.
, 2004
, “Condensation Heat Transfer Coefficients of Flammable Refrigerants
,” Int. J. Refrig.
, 27
(3
), pp. 314
–317
.7.
Park
, K.-J.
, Kang
, D. G.
, and Jung
, D.
, 2011
, “Condensation Heat Transfer Coefficients of R1234yf on Plain, Low Fin, and Turbo-C Tubes
,” Int. J. Refrig.
, 34
(1
), pp. 317
–321
.8.
Fujita
, T.
, and Ueda
, T.
, 1978
, “Heat Transfer to Falling Liquid Films and Film Breakdown—I: Subcooled Liquid Films
,” Int. J. Heat Mass Transfer
, 21
(2
), pp. 97
–108
.9.
Ghiaasiaan
, S. M.
, 2007
, Two-Phase Flow, Boiling, and Condensation: In Conventional and Miniature Systems
, Cambridge University Press
, New York
.10.
Lee
, W. C.
, and Rose
, J. W.
, 1984
, “Forced Convection Film Condensation on a Horizontal Tube With and Without Non-Condensing Gases
,” Int. J. Heat Mass Transfer
, 27
(4
), pp. 519
–528
.11.
Mudawar
, I.
, and El-Masri
, M.
, 1986
, “Momentum and Heat Transfer Across Freely-Falling Turbulent Liquid Films
,” Int. J. Multiphase Flow
, 12
(5
), pp. 771
–790
.12.
Milkie
, J. A.
, 2014
, “Condensation of Hydrocarbons and Zeotropic Hydrocarbon/Refrigerant Mixtures in Horizontal Tubes
,” Ph.D. dissertation
, G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA.13.
Keinath
, B. L.
, 2012
, “Void Fraction, Pressure Drop, and Heat Transfer in High Pressure Condensing Flows Through Microchannels
,” Ph.D. dissertation
, Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA.14.
Bromley
, L. A.
, 1952
, “Effect of Heat Capacity of Condensate
,” Ind. Eng. Chem.
, 44
(12
), pp. 2966
–2969
.15.
Rohsenow
, W.
, 1956
, “Heat Transfer and Temperature Distribution in Laminar Film Condensation
,” Trans. ASME
, 78
, pp. 1645
–1648
.16.
Chen
, S.
, Gerner
, F.
, and Tien
, C.
, 1987
, “General Film Condensation Correlations
,” Exp. Heat Transfer
, 1
(2
), pp. 93
–107
.17.
Uehara
, H.
, and Kinoshita
, E.
, 1994
, “Wave and Turbulent Film Condensation on a Vertical Surface: Correlation for Local Heat-Transfer Coefficient
,” Trans. Jpn. Soc. Mech. Eng. Ser. B
, 60
(577
), pp. 3109
–3116
.18.
Agarwal
, R.
, and Hrnjak
, P.
, 2015
, “Condensation in Two Phase and Desuperheating Zone for R1234ze(E), R134a and R32 in Horizontal Smooth Tubes
,” Int. J. Refrig.
, 50
, pp. 172
–183
.19.
Chamra
, L.
, and Webb
, R. L.
, 1995
, “Condensation and Evaporation in Micro-Fin Tubes at Equal Saturation Temperatures
,” J. Enhanced Heat Transfer
, 2
(3
), pp. 219
–229
.20.
Dobson
, M. K.
, and Chato
, J. C.
, 1998
, “Condensation in Smooth Horizontal Tubes
,” ASME J. Heat Transfer
, 120
(1
), pp. 193
–213
.21.
Yang
, C.
, and Webb
, R.
, 1996
, “Condensation of R-12 in Small Hydraulic Diameter Extruded Aluminum Tubes With and Without Micro-Fins
,” Int. J. Heat Mass Transfer
, 39
(4
), pp. 791
–800
.22.
Cavallini
, A.
, Censi
, G.
, Del Col
, D.
, Doretti
, L.
, Longo
, G. A.
, and Rossetto
, L.
, 2001
, “Experimental Investigation on Condensation Heat Transfer and Pressure Drop of New HFC Refrigerants (R134a, R125, R32, R410A, R236ea) in a Horizontal Smooth Tube
,” Int. J. Refrig.
, 24
(1
), pp. 73
–87
.23.
Del Col
, D.
, Torresin
, D.
, and Cavallini
, A.
, 2010
, “Heat Transfer and Pressure Drop During Condensation of the Low GWP Refrigerant R1234yf
,” Int. J. Refrig.
, 33
(7
), pp. 1307
–1318
.24.
Soliman
, H.
, 1986
, “The Mist-Annular Transition During Condensation and Its Influence on the Heat Transfer Mechanism
,” Int. J. Multiphase Flow
, 12
(2
), pp. 277
–288
.25.
Akers
, W.
, and Rosson
, H.
, 1960
, “Condensation Inside a Horizontal Tube
,” Chemical Engineering Progress Symposium Series
, pp. 145
–150
.26.
Altman
, M.
, Staub
, F.
, and Norris
, R.
, 1960
, “Local Heat Transfer and Pressure Drop for Refrigerant-22 Condensing in Horizontal Tubes
,” Chem. Eng. Progress Symp. Ser.
, 56
(30
).27.
Macdonald
, M.
, and Garimella
, S.
, 2016
, “Hydrocarbon Condensation in Horizontal Smooth Tubes: Part 1—Measurements
,” Int. J. Heat Mass Transfer
, 93
, pp. 75
–85
.28.
Garimella
, S.
, and Bandhauer
, T. M.
, 2001
, “Measurement of Condensation Heat Transfer Coefficients in Microchannel Tubes
,” 2001 Int. Mechanical Engineering Congress and Exposition, New York, Nov. 1–7, Paper No. IMECE 2001/ HTD-24221.29.
Cavallini
, A.
, Censi
, G.
, Del Col
, D.
, Doretti
, L.
, Longo
, G. A.
, and Rossetto
, L.
, 2002
, “Condensation of Halogenated Refrigerants Inside Smooth Tubes
,” HVAC&R Res.
, 8
(4
), pp. 429
–451
.30.
Shah
, M. M.
, 1979
, “A General Correlation for Heat Transfer During Film Condensation Inside Pipes
,” Int. J. Heat Mass Transfer
, 22
(4
), pp. 547
–556
.31.
Cavallini
, A.
, Del Col.
, D.
, Doretti
, L.
, Matkovi
, M.
, Rossetto
, L.
, Zilio
, C.
, and Censi
, G.
, 2006
, “Condensation in Horizontal Smooth Tubes: A New Heat Transfer Model for Heat Exchanger Design
,” Heat Transfer Eng.
, 27
(8
), pp. 31
–38
.32.
Thome
, J. R.
, El Hajal
, J.
, and Cavallini
, A.
, 2003
, “Condensation in Horizontal Tubes—Part 2: New Heat Transfer Model Based on Flow Regimes
,” Int. J. Heat Mass Transfer
, 46
(18
), pp. 3365
–3387
.33.
Macdonald
, M.
, and Garimella
, S.
, 2016
, “Hydrocarbon Condensation in Horizontal Smooth Tubes: Part 2—Heat Transfer Coefficient and Pressure Drop Modeling
,” Int. J. Heat Mass Transfer
, 100
, pp. 1248
–1261
.Copyright © 2017 by ASME
You do not currently have access to this content.
