Title: An exergetic study of a new hybrid heat pump based on R124/DMAC mixture for solar cooling

Authors: D. Lounissi; Nahla Bouaziz; Lakdar Kairouani

Addresses: National Engineering School of Tunis, University of Tunis El-Manar, Energy and Environment Unit (05/UR/11-14), BP, 37, Le BELVEDERE, Tunis 1002, Tunisia ' National Engineering School of Tunis, University of Tunis El-Manar, Energy and Environment Unit (05/UR/11-14), BP, 37, Le BELVEDERE, Tunis 1002, Tunisia ' National Engineering School of Tunis, University of Tunis El-Manar, Energy and Environment Unit (05/UR/11-14), BP, 37, Le BELVEDERE, Tunis 1002, Tunisia

Abstract: This work presents an energetic and exergetic study of a new hybrid absorption heat pump operating at three pressure levels. The absorber is at an intermediate pressure. The installation, subject of this work, is operating with a novel organic couple DMAC/R124 (N,N-dimethylacetamide/2-chloro-1,1,1,2-tetrafluoroethane). Results relative to the new organic absorbent are compared with those relative to the classical water/ammonia working fluids. Investigated parameters are the COP, the irreversibility, and the exergetic efficiency. Results show that performance coefficient of the conventional cycle working with ammonia/water is about 22% for an operating temperature of 80°C while the COP relative to the new proposed cycle is of order of 57% for the same operating temperature. Also, it is noted that the increase of the intermediate pressure improves the COP, limits exergetic losses on the system, and allows lower operating temperatures. We retain the advantages of introducing this organic absorbent in the refrigeration production field.

Keywords: absorption; compression; exergy analysis; DMAC/R124; hybrid heat pumps; organic working fluids; solar cooling; organic absorbents; COP; coefficient of performance; irreversibility; exergy efficiency; refrigeration; solar energy; solar power.

DOI: 10.1504/IJEX.2015.071563

International Journal of Exergy, 2015 Vol.17 No.4, pp.513 - 531

Received: 22 Jun 2014
Accepted: 16 Aug 2014
Published online: 01 Sep 2015 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article