Simulation Research On Lithium Bromide Unit Replace By High Efficiency Electric Chiller In Energy Saving Reconstruction Of Existing Public Buildings

The energy consumption of air-conditioning system accounts for more than 1/3of the energy consumption of the whole building,and its energy-saving transformation is of great significance.Among the types of air-conditioning systems,the lithium bromide refrigeration system has serious unreasonable energy use,and the energy consumption level of the lithium bromide machine room is generally high,so its energy saving potential is the largest.As a high-efficiency energy-generating form,high-efficiency electric refrigeration system provides an efficient and energy-saving solution for lithium bromide system transformation.This paper builds the TRNSYS simulation platform of electric refrigeration system,including the electric refrigeration unit module that integrates the performance curve of the manufacturer,the variable frequency water pump module that integrates the performance curve of the manufacturer,the multi-parameter control strategy realized by MATLAB and some auxiliary modules.Based on the TRNSYS research platform of the refrigerating machine room,this paper completes the energy consumption calculation of the air conditioning system and studies the energy saving strategy of the air conditioning system.Taking the lithium bromide transformation project of Forte Plaza as an example,this paper conducts detailed investigation and energy diagnosis on the original lithium bromide machine room,and analyzes the root cause of “high energy consumption” of lithium bromide equipment room.DeST software was used to simulate the dynamic load of Futai Plaza.According to the simulation results,the equipment selection in the transformation plan was guided,and the load data was provided for TRNSYS simulation.This transformation uses a high-efficiency screw unit to replace the original hot water type lithium bromide unit,eliminate the original low-efficiency water pump,cooling tower and other equipment,and replace the appropriate pump and cooling tower.The construction process uses BIM technology to improve construction efficiency and save costs.At the same time,in order to achieve the lowest energy consumption of the equipment room,the cooling capacity and load are matched,and a PLC group control system is configured.Computer room groupcontrol is an effective way to achieve efficient operation of equipment.This paper studies the energy-saving strategy of air-conditioning system with the goal of minimizing the total energy consumption of the equipment room,and studies the energy efficiency effects of different parameters on the cold machine,and compares the star-by-step method and load rate optimization.The energy consumption performance of the two methods of distribution method optimizes the parameters of cooling tower air flow and cooling water flow under different load rates.Finally,the engineering realization of PLC controlled hardware system and software system is given.Through the data acquisition system,the energy consumption of each electrical equipment,the temperature,pressure and flow data of the water system sampled at intervals of 5 minutes are obtained.Through the comprehensive data screening program to obtain real and reliable data,based on this data set for data processing and analysis,you can calculate the hourly load of the building,the time-consuming power consumption of each device,the hourly efficiency of each device,and the hourly energy efficiency of the cold station.The calculation results can be used for the diagnosis of the original air-conditioning system,and the transformation effect of the lithium bromide machine room after the analysis and transformation.At the same time,it also compares TRNSYS energy consumption.Compared with the measured results,The total energy consumption error of the TRNSYS refrigerating machine room model in Futai Plaza is 9.7%.After transformation,the air conditioning system has obvious energy-saving effect.After the transformation,the average COP of the whole cooling season is 6.91,and the average EER is 4.28.According to the standard coal calculation,the energy saving rate of Futai Plaza in the cooling season is as high as 77.6%.In order to truly reflect the cost and benefit of the lithium bromide room renovation project,this paper uses the full life cycle method to calculate the lithium bromide transformation project of Futai Plaza.During the energy contract period,the energy conservation service company will benefit a total of 762,200 yuan,and the owner will benefit 1.183 million yuan.In terms of environmental benefits,a total of 1.574 million yuan was saved.In summary,in the energy-saving renovation of existing buildings,the replacement of lithium bromide system by electric refrigeration system is atechnology with high return rate and has a wide range of promotion value.The research methods and modification measures used in this paper can be used as a reference for the lithium bromide room renovation project.