A study of condensate retention is presented for plain-fin-and-tube heat exchangers typical to those used in air-cooling applications. An experiment in which the retained mass of air-side condensate was measured under dynamic conditions is described, and the results are analyzed using conventional thermal-hydraulic measurements of j and f. With the coupling between condensate retention and thermal performance established, a new model for predicting the mass of retained condensate is described and compared to the steady-state retention data. The model is successful in predicting retained condensate under relatively restricted conditions. The promise of this new approach, and possible refinements that will add engineering value are discussed.

1.
Bettanini
,
E.
,
1970
, “
Simultaneous Heat and Mass Transfer on a Vertical Surface
,”
International Institute of Refrigeration Bulletin
,
70
, pp.
309
317
.
2.
Guillory
,
J. L.
, and
McQuiston
,
F. C.
,
1973
, “
An Experimental Investigation of Air Dehumidification in a Parallel Plate Heat Exchanger
,”
ASHRAE Trans.
,
79
, pp.
146
151
.
3.
McQuiston
,
F. C.
,
1976
, “
Heat, Mass, and Momentum Transfer in a Parallel Plate Dehumidifying Exchanger
,”
ASHRAE Trans.
,
84
, pp.
266
293
.
4.
Tree
,
D.
, and
Helmer
,
W.
,
1976
, “
Flow in a Parallel Plate Heat Exchanger
,”
ASHRAE Trans.
,
82
, pp.
289
299
.
5.
McQuiston
,
F. C.
,
1978
, “
Heat, Mass, and Momentum Transfer Data for Five Plate-Fin-Tube Heat Transfer Surfaces
,”
ASHRAE Trans.
,
84
, pp.
266
293
.
6.
McQuiston
,
F. C.
,
1978
, “
Correlation of Heat, Mass, and Momentum Transport Coefficients for Plate-Fin-Tube Heat Transfer Surfaces with Staggered Tubes
,”
ASHRAE Trans.
,
84
, pp.
294
308
.
7.
Eckels
,
P. W.
, and
Rabas
,
T. J.
,
1987
, “
Dehumidification: On the Correlation of Wet and Dry Transport Processes in Plate Finned-Tube Heat Exchangers
,”
ASME J. Heat Transfer
,
109
, pp.
575
582
.
8.
Kandlikar, S. G., 1990, “Thermal Design Theory for Compact Evaporators,” in Compact Heat Exchangers, Kraus et al., eds., Hemisphere Publishing Corp., New York, NY, pp. 245–286.
9.
Wang
,
C. C.
,
Hsieh
,
Y. C.
, and
Lin
,
Y. T.
,
1997
, “
Performance of Plate Finned Tube Heat Exchangers Under Dehumidifying Conditions
,”
ASME J. Heat Transfer
,
119
, pp.
109
117
.
10.
Chuah
,
Y. K.
,
Hung
,
C. C.
, and
Tseng
,
P. C.
,
1998
, “
Experiments on Dehumidification Performance of a Finned Tube Heat Exchanger
,”
International Journal of HVAC&R Research
,
4
, pp.
167
178
.
11.
Hong
,
T. K.
, and
Webb
,
R. L.
,
1996
, “
Calculation of Fin Efficiency for Wet and Dry Fins
,”
International Journal of HVAC&R Research
,
2
, pp.
27
41
.
12.
El-Din
,
M. M. S.
,
1998
, “
Performance Analysis of Partially Wet Fin Assembly
,”
Appl. Therm. Eng.
,
18
, pp.
337
349
.
13.
Rosario
,
L.
, and
Rahman
,
M. M.
,
1998
, “
Overall Efficiency of Radial Fin Assembly Under Dehumidifying Conditions
,”
ASME J. Energy Resour. Technol.
,
120
, pp.
299
304
.
14.
Vardhan
,
A.
, and
Dhar
,
P. L.
,
1998
, “
A New Procedure for Performance Prediction of Air Conditioning Coils
,”
Int. J. Refrig.
,
21
, pp.
77
83
.
15.
Mirth
,
D. R.
, and
Ramadhyani
,
S.
,
1993
, “
Prediction of Cooling-Coil Performance under Condensing Conditions
,”
Int. J. Heat Fluid Flow
,
14
, pp.
391
400
.
16.
Mirth
,
D. R.
, and
Ramadhyani
,
S.
,
1994
, “
Correlations for Predicting the Air-Side Nusselt Numbers and Friction Factors in Chilled-Water Cooling Coils
,”
Exp. Heat Transfer
,
7
, pp.
143
162
.
17.
Hu
,
X.
,
Zhang
,
L.
, and
Jacobi
,
A. M.
,
1994
, “
Surface Irregularity Effects of Droplets and Retained Condensate on Local Heat Transfer to Finned Tubes in Cross-Flow
,”
ASHRAE Trans.
,
100
, pp.
375
381
.
18.
Jang
,
J. Y.
,
Lai
,
J. T.
,
Liu
,
L. C.
,
1998
, “
The Thermal-Hydraulic Characteristics of Staggered Circular Finned-Tube Heat Exchangers Under Dry and Dehumidifying Conditions
,”
Int. J. Heat Mass Transf.
,
41
, pp.
3321
3337
.
19.
Fu, W. L., Wang, C. C., and Chang, C. T., 1995, “Effect of Anti-Corrosion Coating on the Thermal Characteristics of a Louvered Finned Tube Heat Exchanger Under Dehumidifying Condition,” Advances in Enhanced Heat/Mass Transfer and Energy Efficiency, ASME HTD-Vol. 320/PID-Vol. 1, pp. 75–81.
20.
Wang
,
C. C.
, and
Chang
,
C. T.
,
1998
, “
Heat and Mass Transfer for Plate Fin-and-Tube Heat Exchangers, With and Without Hydrophilic Coating
,”
Int. J. Heat Mass Transf.
,
41
, pp.
3109
3120
.
21.
Hong, K., 1996, “Fundamental Characteristics of Dehumidifying Heat Exchangers With and Without Wetting Coatings,” Ph.D. thesis, Pennsylvania State University, PA.
22.
Rudy, T. M., and Webb, R. L., 1981, “Condensate Retention on Horizontal Integral-Fin Tubing,” in ASME Advances in Enhanced Heat Transfer, Vol. HTD-18, pp. 35–41.
23.
Rudy
,
T. M.
, and
Webb
,
R. L.
,
1985
, “
An Analytical Model to Predict Condensate Retention on Horizontal Integral-Fin Tubes
,”
ASME J. Heat Transfer
,
107
, pp.
361
368
.
24.
Webb
,
R. L.
,
Rudy
,
T. M.
, and
Kedzierski
,
M. A.
,
1985
, “
Prediction of the Condensation Coefficient on Horizontal Integral-Fin Tubes
,”
ASME J. Heat Transfer
,
107
, pp.
369
376
.
25.
Jacobi
,
A. M.
, and
Goldschmidt
,
V. W.
,
1990
, “
Low Reynolds Number Heat and Mass Transfer Measurements of an Overall Counterflow, Baffled, Finned-Tube, Condensing Heat Exchanger
,”
Int. J. Heat Mass Transf.
,
33
, pp.
755
765
.
26.
Korte, C. M., and Jacobi, A. M., 1997, “Condensate Retention and Shedding Effects on Air-Side Heat Exchanger Performance,” TR-132, ACRC, University of Illinois, Urbana.
27.
Morel
,
T.
,
1975
, “
Comprehensive Design of Axisymmetric Wind Tunnel Contractions
,”
ASME J. Fluids Eng.
,
97
, pp.
225
233
.
28.
Chappuis, J., 1982, “Contact Angles,” in Multiphase Science and Technology, Hewitt et al., eds., 1, Hemisphere Publishing Corporation, Washington, D.C., pp. 387–505.
29.
Johnson, R. E., Jr., and Dettre, R. H., 1969, “Wettability and Contact Angles,” in Surface and Colloid Science, E. Matijevic, ed., 2, Wiley-Interscience, New York, NY, pp. 85–153.
30.
Ware, D. D., and Hacha, T. H., 1960, “Heat Transfer from Humid Air to Fin and Tube Extended Surface Cooling Coils,” ASME Paper No. 60-HT-17.
31.
ARI, 1981, “Standard for Forced-Circulation Air-Cooling and Air-Heating Coils,” ARI-410.
32.
Gnielinski
,
V.
,
1976
, “
New Equations for Heat and Mass Transfer in Turbulent Pipe and Channel Flow
,”
Int. Chem. Eng.
,
16
, pp.
359
368
.
33.
Kays, W. M., and London, A. L., 1984, Compact Heat Exchangers, 3rd ed., McGraw-Hill, New York.
34.
Graham, C., 1969, “The Limiting Heat Transfer Mechanisms of Dropwise Condensation,” Ph.D. thesis, Massachusetts Institute of Technology, MA.
35.
Al-Hayes
,
R. A. M.
, and
Winterton
,
R. H. S.
,
1981
, “
Bubble Diameter on Detachment in Flowing Liquids
,”
Int. J. Heat Mass Transf.
,
24
, pp.
223
230
.
36.
Dimitrakopoulos, P., 1996, “Computational Studies of Droplet Displacement in Stokes Flow,” Ph.D. thesis, University of Illinois, Urbana, IL.
37.
Brown
,
R. A.
,
Orr
, Jr.,
F. M.
, and
Scriven
,
L. E.
,
1980
, “
Static drop on an inclined plate: Analysis by the Finite Element Method
,”
J. Colloid Interface Sci.
,
73
, pp.
76
87
.
38.
Milinazzo
,
F.
, and
Shinbrot
,
M.
,
1988
, “
A Numerical Study of a Drop on a Vertical Wall
,”
J. Colloid Interface Sci.
,
121
, pp.
254
264
.
39.
Yin, J., and Jacobi, A. M., 1999, “Condensate Retention Effects on the Air-Side Heat Transfer Performance of Plain and Wavy-Louvered Heat Exchangers,” TR-158, ACRC, University of Illinois, Urbana.
40.
Kim, G., and Jacobi, A. M., 1999, “Condensate Accumulation Effects on the Air-Side Performance of Slit-Fin Surfaces,” CR-26, ACRC, University of Illinois, Urbana.
You do not currently have access to this content.