Review of water based vapour absorption cooling systems using thermodynamic analysis

Heat based vapour absorption cooling technology is the most appropriate, efficient and eco-friendly way of harnessing solar heat energy, as many cooling load requirements are always in phase with the accumulated solar heat. The performance improvement of such systems has currently become a high research priority, to ensure conservation of electrical energy. Performance of these systems depends on two important factors: i) selection of suitable working fluid pair and ii) adopting appropriate configurations and multiple cascaded 'effects' of the absorption cycles. The Thermodynamic analysis (TDA) or the first law analysis is the broad indicating tool to predict the performance behavior and suitability of a vapour absorption system for a particular application. In the present work, a detailed literature survey has been conducted on various water based working fluid pairs and their cascaded effects; single-effect, double-effect, triple-effect, 1.5-effect and half-effect vapour absorption cooling systems based on TDA. This review paper focuses on two areas: (1) the importance of conducting TDA and choosing right parameters in TDA for performance enhancement in order to overcome the drawbacks of conventional systems. This will help in finding out system for solar based applications, air-cooled applications and determining solutions to overcome crystallization, corrosion, compactness and initial cost; and, (2) as generator temperatures represent the amount of solar heat energy required, considered as key parameter. For various water based vapour absorption systems, the possible range of generator operating temperature requirements and its corresponding attainable COP values has been reviewed and tabulated. This review data can serve as a source of reference in selecting a suitable solar collector with available fluid pair and configuration or vice-versa.