Research On Operation Strategy And Optimization Of Air Conditioning System In A Public Building In Zhengzhou

The energy consumption of centralized air conditioning system in public buildings accounts for a large proportion of the total energy consumption.In the air conditioning system,most of the time is in partial load,and the time of full load only accounts for about 3%of the annual operation time.Problems such as energy waste occur from time to time due to the imperfect operation control strategy of the system.Strengthening the management of air conditioning system and adopting control strategy will-be the key measures to realize its energy-saving operation,and will also bring significant economic and social benefits.This paper takes the central air conditioning system of a large office building in Zhengzhou as the research object.Through field investigation,we find that the equipment and pipeline is aging.The level of management and maintenance is poor,and there is a lack of control strategy for the operation of the air conditioning system.The managements hope to obtain the economic benefits brought by the energy saving of the air conditioning system,but they lack relevant technical knowledge and operation control strategy guidance.In order to study the operation strategy of the air-conditioning equipment,this paper will use TRNSYS to Establish simulation platform.The meteorological parameters from July 1 to October 1 and the actual equipment operation of the building are taken as the research background.The time-interval control strategy of the equipment and the variable flow operation mode of the system are studied.Firstly,the building is modeled and the dynamic load of the building is calculated,which is compared with the design value to verify its accuracy.Combined with the actual data of each equipment,the energy consumption model is established by polynomial fitting method,and the modules in TRNSYS are customized which based on the energy consumption model.Finally,the air-conditioning system is modeled.Based on this model,control strategies are added to simulate and analyze the impact of various control strategies on equipment energy consumption and total system energy consumption.By adjusting the time-interval control strategy of the chiller,the average COP of the simulation time is increased from 5.085 to 5.368,which effectively improves the operation efficiency of the chiller;After setting the control strategy of variable chilled water and cooling water volume,both control strategies can reduce the energy consumption of system,and the energy-saving effect of variable chilled water volume is more significant;When studying the control strategy of variable air volume and variable cooling tower volume,it is found that the maximum air volume is more important for the heat dissipation of cooling tower,and the cooling water flow should be changed on the premise of ensuring the air volume demand to achieve energy-saving effect;When studying the set value of control strategy of variable chilled water and cooling water volume,it is found that the energy consumption of the system is more sensitive to the change of cooling water temperature.Appropriately increasing the cooling water temperature will be better for system energy saving.The research shows that after adding the group control strategy of chillers,chilled water pumps and the control strategy of variable chilled water and cooling water volume,the total energy consumption of the air conditioning system in summer is about 382590kw,which can save 164337kw compared with the original system,and the energy saving rate can reach 30.0%.