Determination of the optimal defrosting initiating time point for an ASHP unit based on the minimum loss coefficient in the nominal output heating energy

Wei Wang, Shiqiang Zhang, Zhaoyang Li, Yuying Sun, Shiming Deng and Xu Wu

Energy, 2020, vol. 191, issue C

Abstract: When an air source heat pump (ASHP) is operated at frosting conditions, controlling its defrosting initiation is very important, which affects its operating efficiency and output heating capacity. Therefore, to improve the accuracy of defrosting initiation of ASHPs under frosting-defrosting operations, an investigation on determination of an optimal defrosting initiating time point (topt) for an ASHP unit based on the minimum loss coefficient in the nominal output heating energy (εNLmin) has been carried out and the investigation results are presented in this paper. Firstly, the existence of topt was verified through a field study. Secondly, the development of multiple-variable-nonlinear models for predicting εNLmin and topt is detailed. Finally, the results of a related modeling study using the developed multiple-variable-nonlinear model for topt is presented. The results from the investigation suggested that initiating defrosting for an ASHP unit at topt could result in the best possible operating performances under its frosting-defrosting operations. It was further demonstrated through the modeling study that at a fixed ambient relative humidity, an increase in ambient air temperature would lead to a decreasing-increasing variation trend in topt, and at a fixed ambient air temperature, topt was decreased with an increase in relative humidity.

Keywords: ASHP units; Frosting and defrosting; Optimal defrosting initiating time point; Loss coefficient in the nominal output heating energy; Multiple-variable-nonlinear model (search for similar items in EconPapers)
Date: 2020
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (4)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0360544219322005
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:energy:v:191:y:2020:i:c:s0360544219322005

DOI: 10.1016/j.energy.2019.116505

Access Statistics for this article

Energy is currently edited by Henrik Lund and Mark J. Kaiser

More articles in Energy from Elsevier
Bibliographic data for series maintained by Catherine Liu ().