直膨式太阳能热泵系统.pdf

Applied Thermal Engineering 29 (2009) 2093–2099Contents lists available at ScienceDirect Applied Thermal Engineering journal homepage: www.elsevier .com/locate /apthermengTwo-stage direct expansion solar-assisted heat pump for high temperature applications S.K. Chaturvedi a, T.M. Abdel-Salamb,*, S.S. Sreedharan a, F.B. Gorozabel a aDepartment of Mechanical Engineering, Old Dominion University, Norfolk, VA 23529, USA bDepartment of Engineering, East Carolina University, Greenville, NC 27858, USAa r t i c l e i n f o Article history: Received 16 November 2007 Accepted 30 October 2008 Available online 7 November 2008 Keywords: Solar-assisted heat pump High temperature applications Direct expansion1359-4311/$ - see front matter  2008 Elsevier Ltd. A doi:10.1016/j.applthermaleng.2008.10.010 * Corresponding author. Tel.: +1 252 328 9649; fax E-mail address: abdelsalamt@ (T.M. Abdel-a b s t r a c t Direct expansion solar-assisted heat pump (DX-SAHP) systems have been proposed as viable alternatives to conventional solar-assisted heat pump systems. This study proposes the use of two-stage DX-SAHP systems for high temperature applications in the range of 60–90 C. The study investigates the capability of these systems of meeting loads with high temperature requirements. The thermal performance of the systems is analyzed for refrigerant R-134a, using a one-cover solar collector. Comparisons between the two-stage DX-SAHP and the single-stage DX-SAHP systems are performed and presented. A graphical procedure is illustrated and used for sizing the solar collector area and the heat pump compressor dis- placement capacity for the two DX-SAHP systems.  2008 Elsevier Ltd. All rights reserved.1. Introduction Heat pumps are devices that are primarily used for space heat- ing and cooling applications. In the heating only mode, they have also been used for domestic hot water (DHW) and industrial pro- cess heat (IPH) applications. A heat pump typically operates be- tween two temperatur