THE ENERGETIC ANALYSIS OF AIR SOURCE HEAT PUMP`S DEFROSTING SYSTEMS

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7408-07-2 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 42, 575-582 pp, DOI: 10.5593/sgem2017/42/S17.072

ABSTRACT

One of the major problems with exploitation of air heat pumps (ASHP) in the cold season, is frosting of outdoor heat exchanger’s surface. A layer of frost accumulated on its surface, leads to decreased heating performance and energetic inefficiency. To restore the ASHP’s nominal capacity, a defrosting process needs to be conducted periodically. The necessity of this procedure causes penalty energy usage, decreasing already low COP in result. Analyzing commonly used ASHP systems, some possibilities of energy efficiency improvement via perfecting their defrosting cycle were noticed. Eventually, a new ASHP defrosting system, based on a reversed refrigerant circuit with simultaneous reorganization of an air flow was developed. This new system is described in following paper. Basing on literature revive and own experimental research, the new defrosting system was compared against commonly used ones. Energy usage, duration of the process and temperature fluctuation during the defrost were considered and results are presented in this paper.

Keywords: Air source heat pump, defrosting, efficiency