Abstract

In this paper, the condensation heat transfer characteristics of R134a inside enhanced tubes using two types of surface structures with different materials were investigated, which were then compared with plain tubes under the same test conditions. The enhanced tubes were: 1EHTa tube with dimpled and petal arrays structure and 1EHTb tube with protrusion and similar petal arrays structure. The experiment was conducted for a mass flux ranging from 100 to 200 kg m−2 s−1 with saturation temperature of 318.15 K. The inlet and outlet vapor qualities were fixed at 0.8 and 0.2, respectively. The test tubes had the same outer diameter of 12.7 mm. Results showed that the dimpled and protruded surface tubes enhanced the convection condensation heat transfer and the heat transfer coefficient was 1.4–1.6 times higher than that of the smooth tube. Heat transfer enhancement of the 1EHTa and 1EHTb tube was mainly due to the complex roughness surface structures that created swirling and increased the interface turbulence. The condensation heat transfer coefficient increased slightly with increasing mass flux. The pressure drop penalty was found to increase as mass flux increased. Compared with the smooth tube, the pressure drop of Cu-1EHTa tube, SS-1EHTa tube, and Cu-1EHTb tube were 1.15, 1.21, and 1.14 of smooth tube, respectively. Enhanced tubes exhibited higher performance factors (PFs) compared to the smooth tube. The average PF was 1.3–1.5. A new correlation of heat transfer coefficient has been developed within ±15% error band.

References

References
1.
Dalkilic
,
A. S.
, and
Wongwises
,
S.
,
2009
, “
Intensive Literature Review of Condensation Inside Smooth and Enhanced Tubes
,”
Int. J. Heat Mass Transfer
,
52
(
15–16
), pp.
3409
3426
.10.1016/j.ijheatmasstransfer.2009.01.011
2.
Patil
,
P. A.
, and
Sapali
,
S. N.
,
2011
, “
Condensation Pressure Drop of HFC-134a and R-404A in a Smooth and Micro-Fin U-Tube
,”
Exp. Therm. Fluid Sci.
,
35
(
1
), pp.
234
242
.10.1016/j.expthermflusci.2010.09.006
3.
Aprea
,
C.
,
Greco
,
A.
, and
Vanoli
,
G. P.
,
2003
, “
Condensation Heat Transfer Coefficients for R22 and R407C in Gravity Driven Flow Regime Within a Smooth Horizontal Tube
,”
Int. J. Refrig.
,
26
(
4
), pp.
393
401
.10.1016/S0140-7007(02)00151-2
4.
Quang
,
V. P.
,
Choi
,
K.-I.
,
Oh
,
J.-T.
, and
Cho
,
H.
,
2019
, “
Flow Condensing Heat Transfer of R410A, R22, and R32 Inside a Micro-Fin Tube
,”
Exp. Heat Transfer
,
32
(
2
), pp.
102
115
.10.1080/08916152.2018.1485783
5.
Olivier
,
J. A.
,
Liebenberg
,
L.
,
Thome
,
J. R.
, and
Meyer
,
J. P.
,
2007
, “
Heat Transfer, Pressure Drop, and Flow Pattern Recognition During Condensation Inside Smooth, Helical Micro-Fin, and Herringbone Tubes
,”
Int. J. Refrig.
,
30
(
4
), pp.
609
623
.10.1016/j.ijrefrig.2006.11.003
6.
Kondou
,
C.
,
Mishima
,
F.
, and
Koyama
,
S.
,
2015
, “
Condensation and Evaporation of R32/R1234ze(E) and R744/R32/R1234ze(E) Flow in Horizontal Microfin Tubes
,”
HVACR Res.
,
21
(
5
), pp.
564
577
.10.1080/23744731.2015.1023163
7.
Kedzierski
,
M.
, and
Goncalves
,
J. M.
,
1999
, “
Horizontal Convective Condensation of Alternative Refrigerants Within a Micro-Fin Tube
,”
J. Enhanced Heat Transfer
,
6
(
2–4
), pp.
161
178
.10.1615/JEnhHeatTransf.v6.i2-4.90
8.
Smit
,
F. J.
, and
Meyer
,
J. P.
,
2002
, “
R-22 and Zeotropic R-22/R-142b Mixture Condensation in Microfin, High-fin, and Twisted Tape Insert Tubes
,”
ASME J. Heat Transfer
,
124
(
5
), pp.
912
921
.10.1115/1.1484394
9.
Fronk
,
B. M.
, and
Garimella
,
S.
,
2013
, “
In-Tube Condensation of Zeotropic Fluid Mixtures: A Review
,”
Int. J. Refrig.
,
36
(
2
), pp.
534
561
.10.1016/j.ijrefrig.2012.11.030
10.
Xie
,
S.
,
Liang
,
Z.
,
Zhang
,
J.
,
Zhang
,
L.
,
Wang
,
Y.
, and
Ding
,
H.
,
2019
, “
Numerical Investigation on Flow and Heat Transfer in Dimpled Tube With Teardrop Dimples
,”
Int. J. Heat Mass Transfer
,
131
, pp.
713
723
.10.1016/j.ijheatmasstransfer.2018.11.112
11.
Li
,
W.
,
Tang
,
W.
,
Chen
,
J.
,
Zhu
,
H.
,
Kukulka
,
D. J.
,
He
,
Y.
,
Sun
,
Z. J.
,
Du
,
J. C.
, and
Zhang
,
B.
,
2018
, “
Convective Condensation in Three Enhanced Tubes With Different Surface Modifications
,”
Exp. Therm. Fluid Sci.
,
97
, pp.
79
88
.10.1016/j.expthermflusci.2018.04.011
12.
Kim
,
N. H.
,
Byun
,
H. W.
, and
Lee
,
J. K.
,
2013
, “
Condensation Heat Transfer and Pressure Drop of R-410a in Three 7.0 mm Outer Diameter Microfin Tubes Having Different Inside Geometries
,”
J. Enhanced Heat Transfer
,
20
(
3
), pp.
235
250
.10.1615/JEnhHeatTransf.2013007609
13.
Guo
,
S. P.
,
Wu
,
Z.
,
Li
,
W.
,
Kukulka
,
D. J.
,
Sundén
,
B.
,
Zhou
,
X. P.
,
Wei
,
J. J.
, and
Simon
,
T.
,
2015
, “
Condensation and Evaporation Heat Transfer Characteristics in Horizontal Smooth, Herringbone and Enhanced Surface EHT Tubes
,”
Int. J. Heat Mass Transfer
,
85
, pp.
281
291
.10.1016/j.ijheatmasstransfer.2015.01.115
14.
Aroonrat
,
K.
, and
Wongwises
,
S.
,
2017
, “
Experimental Study on Two-Phase Condensation Heat Transfer and Pressure Drop of R-134a Flowing in a Dimpled Tube
,”
Int. J. Heat Mass Transfer
,
106
, pp.
437
448
.10.1016/j.ijheatmasstransfer.2016.08.046
15.
Meyer
,
J. P.
, and
Ewim
,
D. R. E.
,
2018
, “
Heat Transfer Coefficients During the Condensation of Low Mass Fluxes in Smooth Horizontal Tubes
,”
Int. J. Multiphase Flow
,
99
, pp.
485
499
.10.1016/j.ijmultiphaseflow.2017.11.015
16.
Meyer
,
J. P.
,
Dirker
,
J.
, and
Adelaja
,
A. O.
,
2014
, “
Condensation Heat Transfer in Smooth Inclined Tubes for R134a at Different Saturation Temperatures
,”
Int. J. Heat Mass Transfer
,
70
, pp.
515
525
.10.1016/j.ijheatmasstransfer.2013.11.038
17.
Hajal
,
J. E.
,
Thome
,
J. R.
, and
Cavallini
,
A.
,
2003
, “
Condensation in Horizontal Tubes, Part 1: Two-Phase Flow Pattern Map
,”
Int. J. Heat Mass Transfer
,
46
(
18
), pp.
3349
3363
.10.1016/S0017-9310(03)00139-X
18.
Kattan
,
N.
,
Thome
,
J. R.
, and
Favrat
,
D.
,
1998
, “
Flow Boiling in Horizontal Tubes: Part 1—Development of a Diabatic Two-Phase Flow Pattern Map
,”
ASME J. Heat Transfer
,
120
(
1
), pp.
140
147
.10.1115/1.2830037
19.
Xiao
,
J.
, and
Hrnjak
,
P.
,
2017
, “
A New Flow Regime Map and Void Fraction Model Based on the Flow Characterization of Condensation
,”
Int. J. Heat Mass Transfer
,
108
, pp.
443
452
.10.1016/j.ijheatmasstransfer.2016.11.104
20.
Zhang
,
H.
,
Fang
,
X.
,
Shang
,
H.
, and
Chen
,
W.
,
2015
, “
Flow Condensation Heat Transfer Correlations in Horizontal Channels
,”
Int. J. Refrig.
,
59
, pp.
102
114
.10.1016/j.ijrefrig.2015.07.013
21.
Cavallini
,
A.
,
Col
,
D.
,
Doretti
,
L.
,
Matkovic
,
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
.10.1080/01457630600793970
22.
Gnielinski
,
V.
,
1976
, “
New Equations for Heat and Mass Transfer in Turbulent Pipe and Channel Flow
,”
Int. Chem. Eng.
,
16
(
2
), pp.
359
368
.
23.
Rouhani
,
S. Z.
, and
Axelsson
,
E.
,
1970
, “
Calculation of Void Volume Fraction in the Subcooled and Quality Boiling Regions
,”
Int. J. Heat Mass Transfer
,
13
(
2
), pp.
383
393
.10.1016/0017-9310(70)90114-6
24.
Shokouhmand
,
H.
,
Salimpour
,
M. R.
, and
Akhavan-Behabadi
,
M. A.
,
2008
, “
Experimental Investigation of Shell and Coiled Tube Heat Exchangers Using Wilson Plots
,”
Int. Commun. Heat Mass Transfer
,
35
(
1
), pp.
84
92
.10.1016/j.icheatmasstransfer.2007.06.001
25.
Moffat
,
R. J.
,
1988
, “
Describing the Uncertainties in Experimental Results
,”
Exp. Therm. Fluid Sci.
,
1
(
1
), pp.
3
17
.10.1016/0894-1777(88)90043-X
26.
Dittus
,
F. W.
, and
Boelter
,
L. M. K.
,
1985
, “
Heat Transfer in Automobile Radiators of the Tubular Type
,”
Int. Commun. Heat Mass Transfer
,
12
(
1
), pp.
3
22
.10.1016/0735-1933(85)90003-X
27.
Jung
,
D.
,
Song
,
K. H.
,
Cho
,
Y.
, and
Kim
,
S. J.
,
2003
, “
Flow Condensation Heat Transfer Coefficients of Pure Refrigerants
,”
Int. J. Refrig.
,
26
(
1
), pp.
4
11
.10.1016/S0140-7007(02)00082-8
28.
Haraguchi
,
H.
,
Koyama
,
S.
, and
Fujii
,
T.
,
1994
, “
Condensation of Refrigerants HCFC 22, HFC 134a and HCFC 123 in a Horizontal Smooth Tube: 2nd Report, Proposal of Empirical Expressions for Local Heat Transfer Coefficient
,”
Trans. JSME
,
60
(
574
), pp.
2117
2124
.10.1299/kikaib.60.2117
29.
Koyama
,
S.
,
Kuwahara
,
K.
,
Nakashita
,
K.
, and
Yamamoto
,
K.
,
2003
, “
An Experimental Study on Condensation of Refrigerant R134a in a Multi-Port Extruded Tube
,”
Int. J. Refrig.
,
26
(
4
), pp.
425
432
.10.1016/S0140-7007(02)00155-X
30.
Dobson
,
M. K.
, and
Chato
,
J. C.
,
1998
, “
Condensation in Smooth Horizontal Tubes
,”
ASME J. Heat Transfer
,
120
(
1
), pp.
193
213
.10.1115/1.2830043
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