Analysis On Applicablity Of Air Conditioning Chilled Water System With Speed Variable Pumps Replacing Control Valves

This thesis foucs on applicablity of air conditioning chilled water system with speed variable pumps replacing control valves, aiming to analyze the new system's characteristics, to explore its design and operational methods and to guide the design and application of practical engineering.Based on analyzing and studying the characteristics of air conditioning chilled water system with speed variable pumps replacing control valves, this thesis has established practical engineering model (PAU + FCU a constant flow pump system). Energy consumptions of new system and traditional system have been simulated by using HDY-SMAD air conditioning load calculation software and DeST simulation software. Plant schemes of one chiller and two chillers were studied under different weather conditions of Beijing, Shanghai and Guangzhou.Variations of motor efficiency and converter efficiency were considered in the calculation of the total pump power consumption.The results of simulation indicate that new systems have a certain energy saving potential under different weather conditions, and energy-saving of large systems are more prominent. Motor loss takes a large proportion in total power of pump when variable frequency pump is used. When flow rate decreases, efficiency of motors of different rated power drop sharply. Therefore, attention must be paid to reducing the motor losses and increasing the motor (especially small-power motors) efficiency. New systems should be reasonably designed and necessary valves should be preserved to achieve optimal energy-saving significant economic and social benefits in practical engineering.