期刊名称：International Research Journal of Environmental Sciences
电子版ISSN：2319-1414
出版年度：2013
卷号：2
期号：10
页码：77-92
语种：English
出版社：International Science Community Association
摘要：Details of the analytical studies of a CO transcritical cycle on a solar assisted heat pump water heating system is presented in this paper. The main components of this system include an evacuated tube U-pipe solar collector serving as the evaporator for the R744 (CO) refrigerant, a variable speed reciprocating compressor, an immersed heat exchanger and an expansion valve. In general, solar heat pumps are known to provide higher values of COP since solar radiation can easily effect higher evaporation temperatures. However, incompatible weather conditions may affect the performance of heat pump, and hence an optimization of such system is essential which is dictated by the dominant operating parameters, such as: solar radiation, solar collector area, speed of the compressor, evaporating and condensing temperatures. A numerical model has been developed to optimize the system design and operating parameters. The developed simulation model can predict the performance of the system COP, solar collector efficiency and heat capacity. For the North Dakota USA weather conditions, the average COP range from 2-3 with solar collector efficiencies of about 40%-60% and temperature of the storage tank water range between 30º-45ºC.
关键词：Solar water heating;heat pumps;CO2;Refrigerant;COP
