Study on Energy Efficient Operation of Air-Conditioning Cooling Water System

Abstract

The control logic of frequency adjustment for pump and cooling tower fan has been presented in this paper, based on the operation mode of a chiller with one pump and one cooling tower. Optimum outlet water temperature control of cooing tower has been put forward through analysis and comparison among factors influencing it, based on measured data. A mathematical model of energy consumption has been established under different outdoor wet-bulb temperature and load rate conditions. The optimized controlling strategy has been obtained after the analysis on energy consumption under two different operational strategies with different number of cooling towers in service. In partial load condition, the best operation mode of cooling water system is the optimal water outlet temperature control system, which aims at the lowest comprehensive system energy consumption. Cooling water system can match the best temperature difference and determine the fan frequency according to optimum outlet temperature automatically. Variable frequency control should be applied to fans; meanwhile, routing maintenance and cleaning is also needed for an even distribution of water and effective use of heat exchange area.