Thermoeconomic optimization for irreversible absorption refrigerators and heat pumps Ali Kodal a , Bahri Sahin b, * , Ismail Ekmekci c , Tamer Yilmaz b a Department of Aeronautical Engineering, Istanbul Technical University, Maslak, 80626 Istanbul, Turkey b Department of Naval Architecture, Yildiz Technical University, Besiktas, 80750 Istanbul, Turkey c Department of Mechanical Engineering, Sakarya University, Esentepe, 54040 Adapazari, Turkey Received 31 July 2001; accepted 26 December 2001 Abstract A performance analysis using finite time thermodynamic based on a thermoeconomic objective function has been performed for absorption irreversible refrigerators and heat pumps. The optimal design para- meters at the maxima of the thermoeconomic objective functions for an absorption refrigerator and heat pumphavebeenderivedanalytically,andtheeffectsoftheinternalirreversibility,theeconomicalparameter and the external temperatures on the global and optimal performances have been discussed. Ó 2002 Elsevier Science Ltd. All rights reserved. Keywords: Absorption refrigerator; Absorption heat pump; Finite time thermodynamics; Thermoeconomic optimi- zation 1. Introduction Absorptionrefrigeratorsandheatpumpsutilize‘‘low-grade’’heatenergy,suchaswasteheatin many industrial processes, heat engines, solar energy and geothermal energy. They have a large potential for saving primary energy and decreasing environmental thermal pollution [1,2]. In the last decade, many optimization and modeling studies for real absorption refrigerators and heat pumps, based on various performance criteria, have been performed by considering finite time and finite size constraints [1–14]. In these studies, the optimal performance characteristics have beeninvestigatedforthecoefficientofperformance[1–7],coolingorheatingload[1,8–10],specific Energy Conversion and Management 44 (2003) 109–123 www.elsevier.com/locate/enconman * Corresponding author. Fax: +90-212-258-2157. E-mail address: sahinb@yildiz.edu.tr (B. Sahin). 0196-8904/03/$ - see front matter Ó 2002 Elsevier Science Ltd. All rights reserved. PII:S0196-8904(02)00046-8