Title: A novel hybrid GAX-ejector absorption refrigeration cycle with an air-cooled absorber

Authors: A.S. Mehr; S.M.S. Mahmoudi; M. Yari; A. Soroureddin

Addresses: Faculty of Mechanical Engineering, University of Tabriz, P.O. Box 1751, Tabriz 51656-87386, Iran ' Faculty of Mechanical Engineering, University of Tabriz, P.O. Box 1751, Tabriz 51656-87386, Iran ' Faculty of Engineering, Department of Mechanical Engineering, University of Mohaghegh Ardabili, P.O. Box 179, Ardabil 56136-51154, Iran ' Faculty of Mechanical Engineering, University of Tabriz, P.O. Box 1751, Tabriz 51656-87386, Iran

Abstract: A novel hybrid generator-absorber heat exchange (GAX)-ejector absorption refrigeration (hybrid GAX-E) cycle, with ammonia-water as working fluid, is proposed and analysed in detail. Thermodynamic models are developed for the hybrid GAX-E, hybrid GAX, simple GAX and single effect ammonia-water absorption refrigeration cycles. A comparison among the performances of these four cycles, at an absorber temperature of 70°C and a generator temperature of more than 170°C, shows that the coefficient of performance (COP) of the hybrid GAX-E cycle is higher than those of the other three cycles. The maximum COP for the hybrid GAX-E cycle is around 1.8 which is about 20%, 125% and 260% higher than the corresponding values for the hybrid GAX, the simple GAX and the single effect cycles, respectively. Results indicate that as the ejector expansion ratio increases from 6.1 to 8.8, the COP of the hybrid GAX-E cycle decreases by up to 53.3%.

Keywords: GAX ejector; generator-absorber heat exchange; hybrid GAX; ammonia-water absorption refrigeration; refrigeration cycle; COP; coefficient of performance; exergy analysis; thermodynamic modelling.

DOI: 10.1504/IJEX.2013.058102

International Journal of Exergy, 2013 Vol.13 No.4, pp.447 - 471

Received: 24 May 2012
Accepted: 29 Dec 2012
Published online: 08 Dec 2013 *

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