Please use this identifier to cite or link to this item: http://hdl.handle.net/10397/43344
Title: An experimental study on defrosting performance for an air source heat pump unit with a horizontally installed multi-circuit outdoor coil
Authors: Song, M
Deng, S 
Mao, N
Ye, X
Keywords: Air source heat pump
Defrosting
Experiment
Horizontally installed
Multi-circuit
Issue Date: 2016
Publisher: Pergamon Press
Source: Applied energy, 2016, v. 165, p. 371-382 How to cite?
Journal: Applied energy 
Abstract: When frost forms and accumulates over the outdoor coil's surface in an air source heat pump (ASHP) unit, system operating performance will be dramatically deteriorated. Reverse cycle defrosting is the most widely used standard defrosting method. A previous related study reported that downwards flowing of melted frost due to gravity over a vertical multi-circuit outdoor coil would decrease the reverse cycle defrosting performance. If the outdoor coil can be changed to horizontally installed, the flow path of melted frost over coil surface can be shortened, and the flow directions of refrigerant and melted frost changed from opposite to orthogonal. Consequently, a better defrosting performance is expected. In this paper, therefore, an experimental study on defrosting performance for an ASHP unit with a horizontally installed multi-circuit outdoor coil was conducted. Experimental results show that, when a vertical outdoor coil was changed to horizontally installed, the defrosting efficiency increased 9.8%, however, with the same defrosting duration at 186 s. Furthermore, when the outdoor air fan was reversed to blowing the melted frost during defrosting, the total mass of the retained water collected decreased 222 g. However, the defrosting efficiency was not increased, but decreased 6.6% because of the heat transfer enhanced between hot coil and cold ambient air.
URI: http://hdl.handle.net/10397/43344
ISSN: 0306-2619
EISSN: 1872-9118
DOI: 10.1016/j.apenergy.2015.12.107
Appears in Collections:Journal/Magazine Article

Access
View full-text via PolyU eLinks SFX Query
Show full item record

SCOPUSTM   
Citations

13
Last Week
0
Last month
Citations as of Jul 29, 2017

WEB OF SCIENCETM
Citations

8
Last Week
0
Last month
Citations as of Aug 13, 2017

Page view(s)

33
Last Week
4
Last month
Checked on Aug 14, 2017

Google ScholarTM

Check

Altmetric



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.