SEASONAL PERFORMANCE OF ON-OFF AIR-TO-WATER HEAT PUMPS
With increasing energy costs, it is essential to be able to predict the annual electricity consumption of heat pumping equipment to compare different systems on a fair basis. Since changes in outdoor conditions and building load affect the heat pump performance, measurement of part-load COP at varied outdoor conditions is necessary. In Europe, Eurovent Certification implemented in 2006 a certification scheme to calculate a European Seasonal Energy Efficiency Ratio (ESEER) for staged capacity chillers. It is expected that such a certification scheme be extended to heat pumping equipment. This paper shows the testing methodology and the results obtained on an On-Off air-towater heat pump (8 kW rated capacity), which was tested at full load as well as part-load conditions (from 90% to 25%) with outdoor conditions varying from –7℃ to 12℃.The test results show that the heat pump COP changed in a different manner depending on the outdoor conditions. The pattern of change was the same for outdoor temperatures above 7℃ and below 0℃. In these two temperature domains, the part-load COP can be related to full load COP following a unique relationship, with a deterioration in performance attributed mainly to stand-by losses under cycling conditions. However, there exists an outdoor temperature domain (roughly between 1 and 6℃) for which part-load COP was found to be higher than full load COP, despite cycling.Consequences for the set-up of a simplified Heating Seasonal Performance Factor based on a reduced number of full load tests and either a simplified performance curve at part load or supplementary part-load test are discussed.
A.BENSAFI M.MONDOT P.RIVIERE
Centre Technique des Industries Aéraulique et Thermique (CETIAT) BP 2042 – 69603 Villeurbanne - Cede Center of Energy and Processes, Ecole des Mines de Paris 60, bd St Michel, 757272 Paris Cedex 06, Fr
国际会议
The 22nd International Congress of Refrigeration(第22届国际制冷大会)
北京
英文
2007-08-21(万方平台首次上网日期,不代表论文的发表时间)