Research On Energy-saving Optimal Control For Central Air Conditioning Water System

Since entering the 21st century,our country’s economy has been developed dramatically.More and more buildings have adopted the central air conditioning system.However,during the peak season of air conditioners in summer,their power consumption has become one of the main sources of power system.According to the relevant department statistics,the current energy consumption of air conditioning system in China accounts for about 48%of the total building energy consumption.Generally,domestic commercial water-cooled central air conditioning system engine room design efficiency is between 0.85-0.95kW/RT,while the actual operation of the annual average of about 1.1-1.3kW/RT.Compared with the developed countries such as Europe and the United States,there is still a lot of room for energy-saving and optimization.Therefore,energy-saving optimal analysis and research on the energy consumption for central air conditioning system has profound significance for energy saving in the construction industry.This thesis takes the refrigeration station energy-saving projects in Dongfeng Nissan’s Huadu factory as background,modeling the main energy-consuming equipment refrigeration station,and use an intelligent method to predict the load of air conditioning.And on this basis,the operating status of each device in the system is optimized.The final design and implementation of the central air conditioning energy-saving optimization system greatly improves the automation of the system operation,effectively reducing the cost of electricity and labor.Based on the existing air conditioning load predicting models(MLR model,ARIMA model and GM model),a RBF neural network prediction model based on residual combination predicting and correction is proposed.After a large amount of data training,it can effectively predict the load demand of the workshop in real time.The average relative error is 1.94%,which greatly improves the effectiveness of the global optimized operating condition model of central air conditioning.A model of central air conditioning water system optimal operating conditions is established.In order to quickly solve the high-dimensional optimal model of such system and the problem of "dimensionality disaster" in high-dimension model and realize online steady-state optimal control.The "decomposition-coordination" algorithm in large-scale system theory is selected to optimize the model.Taking the refrigeration station in Dongfeng Nissan’s Huadu factory as an example,this thesis designs and realizes the central air-conditioning energy-saving group control system,including system network construction,software programming,hardware design and human-machine interface design.Practice has proved that the total energy consumption of the system is significantly reduced after optimization,and energy-saving effect is good.