Title: Energy and exergy analyses of a solar-driven absorption cooling system

Authors: Lavinia Grosu; Alexandru Dobrovicescu; Adrian Untea

Addresses: Laboratoire Energétique, Mécanique et Electromagnétisme, Université Paris Ouest Nanterre La Défense, 50 rue de Sèvres, 92410 Ville d'Avray, France ' Faculté de Mécanique, Université Polytechnique de Bucarest, Splaiul Independentei nr. 313, sector 6, 060042, Bucarest, Romania ' Faculté de Mécanique, Université Polytechnique de Bucarest, Splaiul Independentei nr. 313, sector 6, 060042, Bucarest, Romania

Abstract: In this paper, energy and exergy analyses of an absorption cooling system using H₂O/LiBr and solar energy as heat source are conducted. A simple schematic of a chiller and an improved one, are compared using Thermoptim and EES software. An increase in the coefficient of performance (COP) from 0.69 to 0.8 was noticed. Numerical simulations are performed for six values of the condensing/absorption temperatures, which vary in the interval 31-36°C. The increase in these temperatures implies a decrease in the COP from 0.8 to 0.56. The exergy analysis of the overall system and of each component shows a decrease in the exergetic efficiency of the system from 0.27 to 0.18. A detailed exergy analysis of the absorber reveals the real causes of exergy destruction. A new exergy destruction indicator was introduced, which shows the importance of the irreversibility of each component, relative to the starting potential.

Keywords: solar cooling systems; lithium bromide; exergy analysis; numerical simulation; energy analysis; absorption cooling; solar energy; solar power; coefficient of performance; COP; exergy destruction; irreversibility.

DOI: 10.1504/IJEX.2014.065706

International Journal of Exergy, 2014 Vol.15 No.3, pp.308 - 327

Accepted: 28 Sep 2013
Published online: 30 Apr 2015 *

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