Study On Energy Saving Of Semi-centralized Air-conditioning System Based On The Range Of Load

Nowadays,the world energy situation is grim,which has aroused the wide attention of the world,and China is also facing severe energy challenges.In terms of building energy consumption,due to the unreasonable engineering design and equipment selection of the air conditioning system,the unscientific and untimely operation control and other reasons,the operation of the air conditioning system is generally a waste of energy.In order to realize the efficient utilization of energy,the research on the energy-saving operation of air-conditioning system plays a very important role.This paper takes a high-rise residential building in xi 'an as the prototype.Firstly,the indoor thermal disturbance of the experimental building was obtained through field investigation.Then,energy consumption analysis software EnergyPlus was used to build an air conditioning system.The energy consumption of the building was simulated using dynamic simulation method under the hourly meteorological data provided by ASHRAE.First of all,the variable flow operation of the air-conditioning system is based on the concept of balance between supply and demand of cooling capacity.The building load is in a state of constant change,and the operating parameters of the system are also constantly changing.Through the dynamic simulation of the building load,we obtained the change of the main parameters of the air-conditioning system.Through the simulation of the air conditioning system,the distribution of the main parameters can be obtained.Taking the whole air-conditioning system as a whole,the relationship between variables and system load is analyzed and determined macroscopically.Secondly,real-time variable flow is an ideal system,which has some disadvantages: hysteresis,volatility,uncertainty,etc.In order to alleviate these shortcomings,the operation mode of staged variable flow is proposed,that is,according to the actual distribution of load rate,different control intervals are determined,and the corresponding chilled water flow that can meet the system load demand in the control interval is adopted to adapt to the operation mode of air conditioning system load change.This mode of operation,within a certain range,with a constant flow of frozen water,can alleviate the lag problem of regulation and control,and can increase the stability of system operation.The energy consumption under different working conditions,such as constant flow,variable flow and phased variable flow,is simulated to obtain the energy consumption state under different working conditions,and the energy consumption state under different working conditions is compared.Finally,according to the simulation results,the system load is corresponding to the outdoor temperature,and the outdoor temperature is taken as the reference variable for the system regulation,which makes the system regulation more convenient and easy to understand,and the phased variable flow regulation method based on the load interval is obtained.The energy consumption of chillers is the main aspect of the overall energy consumption of the air-conditioning system.Different combinations of water chillers have great influence on the energy consumption.Based on the load characteristics of the experimental building,this paper simulates the chillers in different combinations and obtains the most energy-saving chiller's combination.