Research On Load Forecast And Control Strategy Of High-efficiency Refrigeration Station Based On Particle Swarm Optimization

The energy consumed by the operation of buildings accounts for 30%of the total global energy consumption,and the CO₂emitted by them accounts for 28%of the total global CO₂ emissions.In order to reduce building carbon emissions and achieve green development,China has proposed a series of countermeasures.Among them,the establishment of high-efficiency refrigeration station and the improvement of the energy efficiency of the refrigeration system are important means to achieve China’s goal of"peaking carbon emissions by 2030 and neutralizing carbon emissions by 2060".In the actual operation of the refrigerating station,the energy consumption of the refrigerating station has remained high due to factors such as unreasonable system design and imperfect control strategy.With the goal of establishing a high-efficiency refrigeration station,this paper studies the application of high-efficiency refrigeration equipment,energy-saving technology and operation control strategies.Based on an example of a refrigeration station in a public building in Qingdao,the design scheme and operation control scheme of the refrigeration system are formulated.Collected the historical operating data of the research objects,analyzed the reasons why the operating efficiency of the refrigeration station is lower than the standard of the high-efficiency refrigeration station.A building cooling load simulation model was built based on De ST,and efficient equipment selection was made based on the simulation results,including high-efficiency screw chillers,variable frequency water pumps,and cooling towers.Based on Revit,a three-dimensional model of the system was established and the resistance of the system in different layouts was analyzed,and the piping system was optimized.The energy consumption simulation platform of the refrigeration station was established by TRNSYS,and the actual cooling load was used as input to compare the energy consumption of the refrigeration station before and after equipment optimization.The accuracy of the simulation platform is tested based on the actual energy consumption of the same type of refrigeration station.The simulation shows that the refrigeration station optimized with high-efficiency equipment combined with control strategies can reduce energy consumption by 129 tce compared with the original operation,and the refrigeration energy efficiency can be increased to 4.68.By optimizing the control strategy,the energy efficiency EER of the refrigeration station can be further improved.Combining load forecasting with particle swarm algorithm,the operation strategy of the refrigeration station is formulated.The BP neural network is selected as the building cooling load forecasting method and a model is established.The historical operation data and meteorological parameters of the building are used as input.The model has good fit and prediction accuracy,and the average relative error is 5.9%.The operating parameters of each device in the refrigeration station are coupled with each other,and only optimizing a single variable cannot make the system run in the best state.In this paper,based on the particle swarm algorithm,the TRNOPT optimization platform is established to optimize the operating parameters of the equipment in the refrigeration station.When the cooling load of the building is constant,the goal is to minimize the energy consumption of the refrigerating station to ensure that the indoor temperature of the building meets the comfort of users,define independent variables,set constraints,and determine the objective function.The four coupled variables of the evaporator set temperature of the chiller,the frequency of the chilled water pump,the frequency of the cooling water pump,and the frequency of the cooling tower fan are optimized to obtain the optimal operation setting parameter table of the equipment under different load rates.A load forecast-parameter optimization control strategy is designed and energy consumption simulation is carried out through TRNSYS and MATLAB.The simulation shows that applying the optimized control strategy to the operation of the target refrigeration station can save energy by 24.9%compared with the operation energy consumption of the refrigeration station under the traditional control strategy,and the EER of the refrigeration station can be increased to 5.5,reaching the standard of high-efficiency refrigeration station.A three-layer refrigerating station group control system at the host computer layer-field control layer-controlled equipment layer is designed to apply the proposed control strategy to practice.This paper studies how to build a high-efficiency refrigeration station from the aspects of refrigeration system design and operation control optimization,and proposes a systematic method for establishing a high-efficiency refrigeration station.The research results obtained can provide a certain reference for the design of similar refrigeration stations.