Journal of Zhejiang University SCIENCE A
ISSN 1673-565X(Print), 1862-1775(Online), Monthly

2009   Vol. 10   No. 11   p. 1678~1682

Experimental investigation of an adjustable ejector for CO₂ heat pump water heaters

Guang-ming CHEN, Li-xia LIANG, Li-ming TANG^†‡, Xiao-xiao XU, Zhi-jiang ZHU, Qi CHEN

(State Key Laboratory of Clean Energy Utilization, Institute of Refrigeration and Cryogenics, Zhejiang University, Hangzhou 310027, China)
^‡ Corresponding Author
^†E-mail: lmtangzju@zju.edu.cn
Received Apr. 8, 2009; revision accepted Aug. 10, 2009; Crosschecked Sept. 10, 2009

Abstract: An adjustable ejector expansion device for a CO₂ heat pump water heater (HPWP) is proposed to improve the system performance. It has been designed to investigate experimentally the effects of the motive nozzle throat area of the ejector, entrained flow pressure, back pressure and primary flow pressure on the entrainment ratio. Experiments based on different motive nozzle throat areas were conducted and the results of the prototype ejector using CO₂ as working fluid are presented. The results show that an adjustable ejector can achieve high performance and work well in a wide range of working conditions.

Key words: Adjustable ejector, System performance, CO₂ heat pump water heater (HPWH), Entrainment ratio
doi:10.1631/jzus.A0920116             CLC number: TK5

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