Graphical Abstract Figure
Graphical Abstract Figure
Close modal

Abstract

To improve the performance of the CO2 heat pump water heater, the spiral groove tube casing heat exchanger is used as a gas cooler. At present, the flow mode of supercritical CO2 (SCO2) flowing between inner and outer tube channels is mainly adopted. However, the efficiency of the gas cooler is studied rarely when the SCO2 flows in the inner tube channel (ITC). So, the heat transfer of SCO2 in the two flow channels are studied and compared in this paper. A physical model of the cooling heat transfer of SCO2 is established for the spiral groove tube casing. The impact of SCO2 pressure, the mass flow ratios of SCO2, and water on the heat transfer attributions of SCO2 in the tube are analyzed using numerical simulation. The conclusions designate that the flow channel in the exchanger can affect the heat transfer attributions of SCO2. When the mass flow ratio of SCO2 becomes lower, the average heat transfer coefficient (h) of SCO2 flowing between inner and outer tube channels is higher, with about 2.09%. As the mass flow ratio of SCO2 rises, the average h of SCO2 flowing in the ITC is higher, with about 3.90%. Moreover, both the safety performance of the system operation and the heat transfer attributions of the working medium should be considered; the flow mode of SCO2 flowing in the ITC is recommended.

References

1.
Liao
,
G.
,
Liu
,
L.
,
Jiaqiang
,
E.
,
Zhang
,
F.
,
Chen
,
J.
,
Deng
,
Y.
, and
Zhu
,
H.
,
2019
, “
Effects of Technical Progress on Performance and Application of Supercritical Carbon Dioxide Power Cycle: A Review
,”
Energy Convers. Manage.
,
199
, p.
111986
.
2.
Austin
,
B. T.
, and
Sumathy
,
K.
,
2011
, “
Transcritical Carbon Dioxide Heat Pump Systems: A Review
,”
Renew. Sustain. Energy Rev.
,
15
(
8
), pp.
4013
4029
.
3.
Ma
,
Y.
,
Liu
,
Z.
, and
Tian
,
H.
,
2013
, “
A Review of Transcritical Carbon Dioxide Heat Pump and Refrigeration Cycles
,”
Energy
,
55
, pp.
156
172
.
4.
Zhu
,
Y.
,
Li
,
C.
,
Zhang
,
F.
, and
Jiang
,
P. X.
,
2017
, “
Comprehensive Experimental Study on a Transcritical CO2 Ejector-Expansion Refrigeration System
,”
Energy Convers. Manage.
,
151
, pp.
98
106
.
5.
Yu
,
Z.
,
Tao
,
L.
,
Huang
,
L.
,
Wang
,
D.
,
Zhang
,
S.
,
Yu
,
Q.
, and
Li
,
M.
,
2021
, “
Numerical Investigation on Cooling Heat Transfer and Flow Characteristics of Supercritical CO2 in Spirally Fluted Tube at Various Inclination Angles
,”
Int. J. Therm. Sci.
,
166
, p.
106916
.
6.
Yu
,
P.-Y.
,
Lin
,
W.-K.
, and
Wang
,
C.-C.
,
2014
, “
Performance Evaluation of a Tube-in-Tube CO2 Gas Cooler Used in a Heat Pump Water Heater
,”
Exp. Therm. Fluid Sci.
,
54
, pp.
304
312
.
7.
Kim
,
J. K.
,
Jeon
,
H. K.
, and
Lee
,
J. S.
,
2007
, “
Wall Temperature Measurement and Heat Transfer Correlation of Turbulent Supercritical Carbon Dioxide Flow in Vertical Circular/Non-circular Tubes
,”
Nucl. Eng. Des.
,
237
(
15–17
), pp.
1795
1802
.
8.
Kim
,
J. K.
,
Jeon
,
H. K.
, and
Lee
,
J. S.
,
2007
, “
Wall Temperature Measurements With Turbulent Flow in Heated Vertical Circular/Non-circular Channels of Supercritical Pressure Carbon-Dioxide
,”
Int. J. Heat Mass Transfer
,
50
(
23–24
), pp.
4908
4911
.
9.
Park
,
J. H.
, and
Kim
,
M. H.
,
2022
, “
Modeling of Local Heat Transfer on Supercritical Pressure CO2 in Horizontal Semicircular Tube
,”
Int. J. Heat Mass Transfer
,
184
, p.
122197
.
10.
Xu
,
R.-N.
,
Luo
,
F.
, and
Jiang
,
P.-X.
,
2015
, “
Experimental Research on the Turbulent Convection Heat Transfer of Supercritical Pressure CO2 in a Serpentine Vertical Mini Tube
,”
Int. J. Heat Mass Transfer
,
91
, pp.
552
561
.
11.
Li
,
Z.
,
Wu
,
Y.
,
Tang
,
G.
,
Zhang
,
D.
, and
Lu
,
J.
,
2015
, “
Comparison Between Heat Transfer to Supercritical Water in a Smooth Tube and in an Internally Ribbed Tube
,”
Int. J. Heat Mass Transfer
,
84
, pp.
529
541
.
12.
Zhang
,
Y.
,
Peng
,
M.
,
Xia
,
G.
, and
Cong
,
T.
,
2019
, “
Numerical Investigation on Local Heat Transfer Characteristics of S-CO2 in Horizontal Semicircular Microtube
,”
Appl. Therm. Eng.
,
154
, pp.
380
392
.
13.
Huang
,
Y.
,
Duan
,
L.
,
Liu
,
D.
, and
Wang
,
Y.
,
2022
, “
Computational Investigation on Heat Transfer of Supercritical CO2 in Horizontal U-Tubes
,”
J. Supercrit. Fluids
,
188
, p.
105690
.
14.
Xu
,
W.
,
Xu
,
B.
,
Wang
,
X.
, and
Chen
,
Z.
,
2022
, “
Heat Transfer Characteristics of Supercritical CO2 in Square Microchannels
,”
J. Chem. Eng.
,
73
(
4
), pp.
1534
1545
.
15.
Sun
,
E.
,
Xu
,
J.
,
Li
,
M.
,
Liu
,
G.
, and
Zhu
,
B.
,
2018
, “
Connected-Top-Bottom-Cycle to Cascade Utilize Flue Gas Heat for Supercritical Carbon Dioxide Coal Fired Power Plant
,”
Energy Convers. Manage.
,
172
, pp.
138
154
.
16.
Zhang
,
W.
,
Wang
,
S.
,
Li
,
C.
, and
Xu
,
J.
,
2015
, “
Mixed Convective Heat Transfer of CO2 at Supercritical Pressures Flowing Upward Through a Vertical Helically Coiled Tube
,”
Appl. Therm. Eng.
,
88
, pp.
61
70
.
17.
Xu
,
J.
,
Yang
,
C.
,
Zhang
,
W.
, and
Sun
,
D.
,
2015
, “
Turbulent Convective Heat Transfer of CO2 in a Helical Tube at Near-Critical Pressure
,”
Int. J. Heat Mass Transfer
,
80
, pp.
748
758
.
18.
Xu
,
X.
,
Zhang
,
Y.
,
Liu
,
C.
,
Zhang
,
S.
, and
Dang
,
C.
,
2018
, “
Experimental Investigation of Heat Transfer of Supercritical CO2 Cooled in Helically Coiled Tubes Based on Exergy Analysis
,”
Int. J. Refrig.
,
89
, pp.
177
185
.
19.
Jaddoa
,
A.-A.
,
2021
, “
Convection Heat Transfer Analysis With Flow Resistance for Mini-helically Coiled Tubes at Supercritical Pressures Experimentally
,”
Int. J. Heat Technol.
,
39
, pp.
817
824
.
20.
Liu
,
X.
,
Xu
,
X.
,
Liu
,
C.
,
Ye
,
J.
,
Li
,
H.
,
Bai
,
W.
, and
Dang
,
C.
,
2017
, “
Numerical Study of the Effect of Buoyancy Force and Centrifugal Force on Heat Transfer Characteristics of Supercritical CO2 in Helically Coiled Tube at Various Inclination Angles
,”
Appl. Therm. Eng.
,
116
, pp.
500
515
.
21.
Liu
,
X.
,
Xu
,
X.
,
Liu
,
C.
,
He
,
J.
, and
Dang
,
C.
,
2019
, “
The Effect of Geometry Parameters on the Heat Transfer Performance of Supercritical CO2 in Horizontal Helically Coiled Tube Under the Cooling Condition
,”
Int. J. Refrig.
,
106
, pp.
650
661
.
22.
Liu
,
X.
,
Xu
,
X.
,
Liu
,
C.
,
Bai
,
W.
, and
Dang
,
C.
,
2018
, “
Heat Transfer Deterioration in Helically Coiled Heat Exchangers in Trans-critical CO2 Rankine Cycles
,”
Energy
,
147
, pp.
1
14
.
23.
Zhang
,
S.
,
Xu
,
X.
,
Liu
,
C.
,
Zhang
,
Y.
, and
Dang
,
C.
,
2018
, “
The Buoyancy Force and Flow Acceleration Effects of Supercritical CO2 on the Turbulent Heat Transfer Characteristics in Heated Vertical Helically Coiled Tube
,”
Int. J. Heat Mass Transfer
,
125
, pp.
274
289
.
24.
Bai
,
W.
,
Zhang
,
S.
,
Li
,
H.
, and
Xu
,
X.
,
2019
, “
Effects of Abnormal Gravity on Heat Transfer of Supercritical CO2 in Heated Helically Coiled Tube
,”
Appl. Therm. Eng.
,
159
, p.
113833
.
25.
Wang
,
K.
,
Xu
,
X.
,
Wu
,
Y.
,
Liu
,
C.
, and
Dang
,
C.
,
2015
, “
Numerical Investigation on Heat Transfer of Supercritical CO2 in Heated Helically Coiled Tubes
,”
J. Supercrit. Fluids
,
99
, pp.
112
120
.
26.
Jackson
,
J.
, and
Hall
,
W.
,
1979
,
Turbulent Forced Convection in Channels and Bundles
,
Hemisphere Publishing Corporation
,
New York
, pp.
613
640
.
27.
Yang
,
M.
,
2016
, “
Numerical Study of the Heat Transfer to Carbon Dioxide in Horizontal Helically Coiled Tubes Under Supercritical Pressure
,”
Appl. Therm. Eng.
,
109
, pp.
685
696
.
28.
Wang
,
P. C.
,
2019
,
Research on Heat Transfer Performance of Spiral Groove Pipe Based on Finite Element Analysis
,
School of Mechanical Engineering, University of Shanghai for Science and Technology
,
Shanghai, China
.
29.
Zhu
,
Y.
,
Huang
,
Y.
,
Lin
,
S.
,
Li
,
C.
, and
Jiang
,
P.
,
2019
, “
Study of Convection Heat Transfer of CO2 at Supercritical Pressures During Cooling in Fluted Tube-in-Tube Heat Exchangers
,”
Int. J. Refrig.
,
104
, pp.
161
170
.
30.
Wang
,
W.
,
Ye
,
Z.
,
Yin
,
X.
,
Song
,
Y.
,
Cui
,
C.
, and
Cao
,
F.
,
2024
, “
Theoretical and Experimental Studies for a Transcritical CO2 Heat Pump With Spirally Fluted Tube Gas Cooler
,”
Appl. Therm. Eng.
,
236
, p.
121414
.
31.
Du
,
D.
,
Tao
,
L.
,
Li
,
M.
,
Qiu
,
H.
,
Li
,
Z.
, and
Huang
,
L.
,
2022
, “
Experimental Study on Heat Transfer Characteristics of Supercritical CO2 in Spiral Grooved Tube
,”
Chem. Eng.
,
50
(
3
), pp.
36
41
.
32.
Qui
,
H.
,
Tao
,
L.
,
Yu
,
Z.
, and
Li
,
M.
,
2023
, “
Numerical Study of Heat Transfer and Pressure Drop Characteristics of Supercritical CO2 in a Horizontal Spiral Fluted Tube
,”
Heating Ventilating Air Cond.
,
53
(
3
), pp.
154
160
.
33.
Chen
,
X. D.
,
Xu
,
X. Y.
,
Nguang
,
S.-K.
, and
Bergles
,
A.-E.
,
2001
, “
Characterization of the Effect of Corrugation Angles on Hydrodynamic and Heat Transfer Performance of Four-Start Spiral Tubes
,”
ASME J. Heat Transfer
,
123
(
6
), pp.
1149
1158
.
34.
Wang
,
L.
,
Sun
,
D. W.
,
Liang
,
P.
,
Zhuang
,
L.
, and
Tan
,
Y.
,
2000
, “
Heat Transfer Characteristics of Carbon Steel Spirally Fluted Tube for High Pressure Preheaters
,”
Energy Convers. Manage.
,
41
(
10
), pp.
993
1005
.
35.
Yu
,
Z.
,
Tao
,
L.
,
Huang
,
L.
, and
Wang
,
D.
,
2020
, “
Numerical Investigation on Cooling Heat Transfer and Flow Characteristic of Supercritical CO2 in Spirally Fluted Tubes
,”
Int. J. Heat Mass Transfer
,
163
, p.
120399
.
36.
Li
,
M.
,
Tao
,
L.
,
Yu
,
Z.
, and
Yu
,
Q.
,
2021
, “
Numerical Simulation of Supercritical CO2 Cooling Heat Transfer in Different Heat Exchange Tubes
,”
Chem. Eng.
,
49
(
10
), pp.
54
73
.
37.
Li
,
M.
,
Tao
,
L.
,
Yu
,
Z.
, and
Yu
,
Q.
,
2021
, “
Numerical Investigation on Cooling Heat Transfer of Supercritical CO2 in Horizontal Spiral Groove Tube
,”
Therm. Power Eng.
,
36
(
4
), pp.
51
59
.
38.
Rajendra Prasad
,
K. S.
,
Krishna
,
V.
,
Sachin
,
B.
, and
Rao
,
P. B.
,
2022
, “
Turbulent Heat Transfer Characteristics of Supercritical Carbon Dioxide for a Vertically Upward Flow in a Pipe Using Computational Fluid Dynamics and Artificial Neural Network
,”
ASME J. Heat Transfer.
,
144
(
1
), p.
011802
.
39.
Lemmon
,
E.
,
Mclinden
,
M.
, and
Hube
,
M.
,
2010
,
Reference Fluid Thermodynamic and Transport Properties Database (REFPROP). NIST Standard Reference Database 23, Version 9.1
,
National Institute of Standards and Technology (NIST)
,
Gaithersburg
, Mendenley Data.
40.
Agrawal
,
N.
, and
Bhattacharyya
,
S.
,
2011
, “
Experimental Investigations on Adiabatic Capillary Tube in a Transcritical CO2 Heat Pump System for Simultaneous Water Cooling and Heating
,”
Int. J. Refrig.
,
34
(
2
), pp.
476
483
.
41.
Alfredo
,
C. E.
,
2006
,
The Complete Part Design Handbook: For Injection Molding of Thermoplastics
,
Hanser Gardner Publications
,
Cincinnati, OH
.
You do not currently have access to this content.