Reseyarch On Controland Energy Consumption Of Cooling Water System In VAV Air Conditioning System

With the rapid economic development of the society,people's living environment requirements have not limited the basic needs of daily life.More and more attention are concentrated on the comfort of living environment.But the energy consumption of buildings is also increasing with the upgrading of the building quality.And for public buildings,the central air-conditioning system is the most energy-consuming part,so the central air-conditioning energy-saving strategy is of great significance.VAV air conditioning system,including wind system,water system and hot and cold heat source system,which water system as the main energy consumption system,energy consumption more than half of the total energy consumption.At present,the research of energy saving strategy of chilled water system is relatively mature.By changing the flow rate of chilled water system,the equipment can control the minimum power operation under the premise of meeting the load requirement,so as to reduce the energy consumption of the system.But the cooling water system between the equipment is more complex,the system variable flow operation can be reduced to a certain extent cooling tower fan and cooling water pump energy consumption,But when the cooling tower water temperature or cooling tower outlet flow is too low,will lead to chillers energy consumption rise,resulting in increased energy consumption throughout the system,so how to effectively use the variable flow mode of operation to reduce the system energy needs further study.This paper first analyzes the energy-saving method and the feasibility of cooling water system,the condensate temperature control method is adopted to control the variable flow of the cooling water system.Secondly,according to the characteristics of the equipment in the cooling water system,according to the least squares and useing Labview and Matlab software to establish the control model and energy consumption model,After that,control the chilled water system and the air system effectively so as to keep them running in a relatively stable range.In order to optimize the system control,this paper designs a PID controller based on genetic simulated annealingalgorithm to control the water temperature and cooling water flow of the cooling tower as the controlled object.The control program written by Labview is connected with the Matlab program of this algorithm to realize the online PID parameter tuning,in order to control the cooling tower water temperature or cooling tower water flow fluctuations in the vicinity of the optimal point to achieve the cooling water system energy-saving operation,and then in the Qingdao University of Technology air conditioning laboratory platform to use this control strategy,and through Labview data collection The results show that the energy saving effect of this control strategy is obvious.The results show that the energy consumption of each device is compared with that of the control method.