THERMOECONOMIC ANALYSIS OF VAPOUR ABSORPTION AIR CONDITIONING SYSTEM

Abstract

Thermal systems cannot always be optimised by means of mathematical or numerical techniques, because a complete model of the plant is not always available. Furthermore, mathematical or numerical optimisation simply applies to one specified structure of the system whereas, often, structural modifications would be able to improve the effectiveness of the plant. Thermoeconomics is a discipline, which combines concepts of exergy method with those belonging to economic analysis. The purpose of thermoeconomic optimisation is to achieve, within a given system structure, a balance between expenditure on capital costs and energy costs which will give a minimum cost of the plant product. In this work, an attempt has been made to optimise a vapour absorption air conditioning system with the help of thermoeconomic analysis. First of all, the exergy analysis of the components of the system is carried out to have an understanding of the performance of the components. Then a simplified cost minimisation methodology is applied to evaluate the economic cost of all the internal flows and products . of the installation. Once these cost have been calculated a design configuration not far from the real global optimum can be obtained by means of thermoeconomic variables associated with each system component, carried out unit by unit. It has been found that a remarkable improvement of the system can be achieved with suitable modifications of the system components.