An exergy based comparative study between LiBr/water absorption refrigeration systems from half effect to triple effect

• Published in: Applied thermal engineering 2017-09, Vol.124, p.103-123
• Main Authors: Maryami, R., Dehghan, A.A.
• Format: Article
• Language: English
• Subjects: Absorption refrigeration systems; Effects; Efficiency; Energy; Exergy; Exergy analysis; LiBr/water; Refrigerating; Refrigeration; Water; Water absorption
• ISSN: 1359-4311; 1873-5606
• DOI: 10.1016/j.applthermaleng.2017.05.174

•Comparison of five different absorption systems operating with LiBr/water.•Investigation of systems operation based on the first and second law of thermodynamics.•Determining optimum generator temperature based on the maximum efficiencies.•Presentation of a new formula to calculate entropy of Lithium bromide. In this paper a comparative study was performed between five classes of LiBr/water absorption refrigeration systems to investigate the influence of various operating parameters on the coefficient of performance, the thermal loads of the components, the exergetic efficiency and the total change in the exergy of systems. The exergetic analysis of all system’s components was done after their energy analysis. The half effect, single effect, series class of double effect, parallel class of double effect and triple effect absorption refrigeration cycles were compared together in this study. The exergetic evaluation of the thermodynamic flows, which go through this cycle, was performed for a refrigerating capacity 300kW. According to energetic and exergetic analysis, the results showed that the coefficient of performance and exergy efficiency increases from the half effect, to the single, double and triple effect refrigeration system while total exergy change approximately decreases. Furthermore, it was found that there is an optimum generator temperature where the COP and exergy efficiency of the five configurations of absorption refrigeration systems is maximum and the total exergy change becomes minimum.