Abstract
The frost mass in different rows of the outdoor heat exchanger of an air source heat pump is uneven when the ambient temperature is below 0 °C, which leads to a shorter defrosting interval and reduces the heating capacity of the heat pump. In order to improve the problem of uneven frost along the airflow direction in the evaporator, an experimental study is conducted on the frosting and heat transfer performance of three rows of variable pitch (VP) finned coils in different fin pitch combinations under low ambient temperature conditions. The results show that the frosting time of the sample with VP of 5*3*2 is extended by 46.67%, the frost mass per unit of bare tube surface area is reduced by 14.54%, and the average heat transfer power per unit mass and volume is increased by 37.64% and 33.56%, respectively.
Issue Section:
Heat Exchangers
References
1.
Okbaz
,
A.
,
Pınarbaşı
,
A.
, and
Olcay
,
A. B.
, 2020
, “
Experimental Investigation of Effect of Different Tube Row-Numbers, Fin Pitches and Operating Conditions on Thermal and Hydraulic Performances of Louvered and Wavy Finned Heat Exchangers
,” Int. J. Therm. Sci.
,
151
, p. 106256
.10.1016/j.ijthermalsci.2019.1062562.
China's National Energy Administration
, 2021
, “Adjust Measures to Local Conditions to do a Good Job of Renewable Energy Heating Work Notice
,”
China's National Energy Administration
, Beijing, China.3.
Hayashi
,
Y.
,
Aoki
,
A.
,
Adachi
,
S.
, and
Hori
,
K.
, 1977
, “
Study of Frost Properties Correlating With Frost Formation Types
,” ASME J. Heat Transfer-Trans. ASME
,
99
(2
), pp. 239
–245
.10.1115/1.34506754.
Wang
,
W. Y.
, and
Li
,
Y. Y.
, 2019
, “
Intermediate Pressure Optimization for Two-Stage Air-Source Heat Pump With Flash Tank Cycle Vapor Injection Via Extremum Seeking
,” Appl. Energy
,
238
, pp. 612
–626
.10.1016/j.apenergy.2019.01.0835.
Amer
,
M.
, and
Wang
,
C. C.
, 2017
, “
Review of Defrosting Methods. Renewable and Sustainable
,” Energy Rev.
,
73
, pp. 53
–74
.10.1016/j.rser.2017.01.1206.
Sourbron Maarten
,
G.
, and
Nesrin
,
O.
, 2016
, “
Determination of Heat Transfer Characteristics of Solar Thermal Collectors as Heat Source for a Residential Heat Pump
,” J. Sol. Energy Eng.
,
138
(4
), p. 041011
.10.1115/1.40335957.
Wang
,
M.
,
Zang
,
R. Q.
,
Feng
,
H.
,
Yu
,
C. Q.
,
Wang
,
H.
, and
Zhang
,
C. X.
, 2018
, “
Study on the Liquid Refrigerant Defrosting System and the Defrosting Rule
,” J. Therm. Sci. Eng. Appl.
,
10
(5
), p. 051023
.10.1115/1.40402848.
Jones
,
B. W.
, and
Parker
,
J. D.
, 1975
, “
Frost Formation With Varying Environmental Parameters
,” ASME J. Heat Transfer-Trans. ASME
,
97
(2
), pp. 255
–259
.10.1115/1.34503509.
Lee
,
W.-J.
,
Bae
,
K. J.
, and
Kwon
,
O. K.
, 2020
, “
Effect of Hydrophobic Surfaces on Frost Retardation in Fin-Tube Heat Exchangers With Various Fin Pitches
,” Appl. Therm. Eng.
, 176, p. 115424.10.1016/j.applthermaleng.2020.11542410.
Pu, L., Liu, R., Huang, H., Zhang, S. Q., Qi, Z. G., Xu, W. D., and Zhou, J., 2020, “Experimental Study of Cyclic Frosting and Defrosting on Micro-Channel Heat Exchangers With Different Coatings,”
Energy Build.
, 226, p. 110382.10.1016/j.enbuild.2020.11038211.
Lei
,
S. W.
,
Song
,
M. J.
,
Libor
,
P.
, and
Shen
,
J.
, 2021
, “
A Numerical Study on Frosting and Its Early Stage Under Forced Convection Conditions With Surface and Environmental Factors Considered
,” Sustainable Energy Technol. Assess.
,
45
, p. 101202
.10.1016/j.seta.2021.10120212.
Ho
,
J. C.
,
Bin
,
L. J.
,
Hyuk
,
L. S.
,
Jungho
,
L.
,
Mun
,
Y. S.
, and
Kyoung
,
C. C.
, 2016
, “
Frosting Characteristics on Hydrophilic and Superhydrophobic Copper Surfaces
,” ASME J. Heat Transfer-Trans. ASME
,
138
(2
), p. 020913
.10.1115/1.403225713.
Martínez-Frías
,
J.
, and
Aceves
,
S. M.
, 1999
, “
Effects of Evaporator Frosting on the Performance of an Air-to-Air Heat Pump. Journal of Energy Resources Technology
,” J. Energy Res. Technol.
,
121
(1
), pp. 60
–65
.10.1115/1.279506114.
Zhang
,
L.
,
Jiang
,
Y.
,
Dong
,
J.
,
Yao
,
Y.
, and
Deng
,
S.
, 2018
, “
An Experimental Study of Frost Distribution and Growth on Finned Tube Heat Exchangers Used in Air Source Heat Pump Units
,” Appl. Therm. Eng.
,
132
, pp. 38
–51
.10.1016/j.applthermaleng.2017.12.04715.
Liu
,
J.
,
Zhao
,
B.
, and
Xie
,
Y. M.
, 2020
, “
Analysis of the Influence of Fin Spacing on the Performance Fin-Tube Heat Exchanger
,” Mach. Des. Manuf.
, (11
), pp. 82
–85
.10.19356/j.cnki.1001-3997.2020.11.02116.
Rao
,
W.
, and
Lu
,
Y. J.
, 2007
, “
Characteristic Analysis on Air Source Heat Pump With Variable Spacing Fin Heat Exchanger in Frosting Condition
,” J. Harbin Inst. Technol.
,
39
(10
), pp. 1596
–1600
.10.3321/j.issn:0367-6234.2007.10.02017.
Rao
,
W.
, and
Lu
,
Y. J.
, 2005
, “
Simulation and Analysis for Air Source Heat Pump Variable Finned-Tube Heat Exchangers Under Frosting Conditions
,” Proceedings of the Annual Conference of Refrigeration and Air Conditioning of China Refrigeration Society
, Kunming, Yunnan, China, pp. 161
–166
.18.
Lang
,
Q. Y.
,
Shen
,
J.
, and
Yang
,
N.
, 2003
, “
Improvement of Finned Tube Evaporator Under Frosting Condition
,” Refrig.
,
022
(003
), pp. 47
–51
.10.3969/j.issn.1005-9180.2003.03.01119.
Qin
,
H. J.
, and
Li
,
W. Z.
, 2014
, “
Simulation and Experiment on Performance of Air Cooler With Variable Pitch in Frosting Conditions
,” J. Therm. Sci. Eng. Appl.
,
13
(3
), pp. 206
–212
.10.13738/j.issn.1671-8097.2014.03.003Copyright © 2022 by ASME
You do not currently have access to this content.
