IMPROVING THE PERFORMANCE OF COOLING WATER SYSTEMS USING EXERGY ANALYSIS - A NOVEL APPROACH

摘要

Circulating cooling water systems almost serve all the operations of industrial plants where there is requirement of an external heat sink for heat removal and temperature control. Research on cooling systems focused on the energy analysis of individual components, cooling tower and heat exchanger network. However, the energy concept, alone is insufficient to describe the energy efficiency of the whole system. In this study, the exergy analysis is applied to evaluate the performance of the circulating cooling water system. To achieve this objective, the exergy destruction of the cooling tower and heat exchanger network in terms of different operational conditions are investigated. The results indicated that the exergy destruction in the cooling tower is increased by increasing the cooling tower inlet temperature; whereas the exergy destruction of the heat exchanger network decreases. Therefore, the problem of cooling water system for performance evaluation becomes an optimisation problem to search for the minimum exergetic destruction. Additionally, the second law efficiency of the cooling tower and water network is studied through the exergetic analysis.