Title: Performance investigation of a diffusion absorption refrigeration system using nano-size alumina particles in the refrigerant

Authors: Adnan Sözen; Engin Özbaş; Tayfun Menlik; Ümit İskender; Cuma Kılınç; M. Tarık Çakır

Addresses: Technology Faculty, Department of Energy Systems Engineering, Gazi University, Teknikokullar, 06503 Ankara, Turkey ' Ondokuz Mayis University, Yesilyurt D.C. Vocational School, Samsun 55300, Turkey ' Technology Faculty, Department of Energy Systems Engineering, Gazi University, Teknikokullar, 06503 Ankara, Turkey ' Technology Faculty, Department of Energy Systems Engineering, Gazi University, Teknikokullar, 06503 Ankara, Turkey ' Technology Faculty, Department of Energy Systems Engineering, Gazi University, Teknikokullar, 06503 Ankara, Turkey ' Technology Faculty, Department of Energy Systems Engineering, Gazi University, Teknikokullar, 06503 Ankara, Turkey

Abstract: In this study, the effects of the passive heat transfer improvement method of coupling ammonia/water with nano-size alumina (Al₂O₃) particles were examined in regard to the heat performance of a diffusion absorption refrigeration system (DARS). Adding nanoparticles into the fluid leads to significant improvement in heat transfer since the surface area and heat capacity of the fluid increase due to the high surface area of the nanoparticles. In this study, cooling/absorption fluid mixtures with Al₂O₃ nanoparticles and their impact on system energy and exergy performance were assessed. The results of experiments indicated that the system with nanoparticles provided better absorption of heat from the generator and faster evaporation of the cooler from the cooling/absorption fluid. Addition of alumina nanoparticles to DARS improved the system's coefficient of performance (COP) and exergetic coefficient of performance (ECOP) by 55.56% and 22.8%, respectively, and reduced the circulation ratio (f) by 51.72%.

Keywords: diffusion absorption refrigeration; energy analysis; exergy analysis; nanofluids; nanotechnology; performance evaluation; alumina nanoparticles; refrigerants; heat transfer; ammonia; water; cooling.

DOI: 10.1504/IJEX.2015.072910

International Journal of Exergy, 2015 Vol.18 No.4, pp.443 - 461

Received: 21 Jun 2014
Accepted: 17 Dec 2014
Published online: 07 Nov 2015 *

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