Energy Saving Effect Of Coordinated Optimization Strategy For Variable Chilled Water Temperature And VAV In Centralized Air-conditioning System

With the improvement of people’s living standard,the centralized air-conditioning system has been used to improve the thermal comfort of people’s living places and workplaces,however,the energy consumption of centralized air-conditioning system is becoming more and more energy-intensive.Therefore,in respond to the national energy saving call and improve the efficiency of building energy utilization,it is necessary to optimize the operation strategy of centralized air-conditioning system.Base on VAV air-conditioning system,this paper takes the strategy of adjusting the chilled water supply temperature,and optimizes the energy consumption of the centralized air-conditioning system by coordinating and optimizing the operation strategy of variable air volume and variable chilled water supply temperature.The energy consumption of the centralized air-conditioning system with the variable chilled water supply temperature control strategy needs to be reduced overall,in addition,it is not only to reduce the energy consumption of chiller,but also to meet the requirements of air-conditioning design parameters of buildings.Based on the experimental platform of VAV air-conditioning system and the verified TRNSYS simulation model,this paper will analyze the optimal temperature of chilled water supply system in VAV air-conditioning system under different load ratio,and explore the energy saving effect of centralized air-conditioning system under the variable chilled water supply temperature strategy.Firstly,in this paper,the principle and control strategy of VAV and variable chilled water supply temperature of air-conditioning system and TRNSYS simulation software are introduced,each mathematical model of centralized air-conditioning system units are given,and the simulation model of VAV air-conditioning system is established.Then,this paper will verify the reliability of the model and modify the simulation model according to the experimental data,analy the effect of variable chilled water temperature on the performance of the centralized air-conditioning system units under different load ratio,find the most energy-efficient temperature setting value of the chilled water supply in centralized air-conditioning system under different load ratio.Finally,under the same experimental conditions,this paper will compare the energy consumption and the temperature and humidity control of the air-conditioning area of VAV air-conditioning system under variable chilled water supply temperature strategy with the air-conditioning area of VAV air-conditioning system under constant chilled water supply temperature strategy,we find the VAV air-conditioning system under the strategy of variable chilled water supply temperature can keep the room temperature at 26℃,and keep the relative humidity stays in the range of 40% ~ 50% for most of time.And the overall energy consumption is 5.88% lower than before,the chiller energy consumption is 8.03% lower than before.The results of research show that the centralized air-conditioning system under variable chilled water supply temperature strategy helps to reduce overall energy consumption of the system,and has little impact on the thermal comfort of the air-conditioning area.It can provide reference for the early design and later operation of the centralized air-conditioning system in the actual project.