| In recent years,China has continued to deepen economic reform and industrial adjustment,and the data center industry has also ushered in a period of rapid development with the continuous improvement of informatization in all walks of life.By 2018,the global IDC market has reached 62.51 billion yuan,with a growth rate of 23.6%.At the same time,the total market size of IDC in China reached RMB 122.8 billion,up 29.8% year on year.With the continuous expansion of the scale of data center,the problem of energy consumption is increasingly prominent.According to relevant data,the power consumption of data center in China is expected to reach 250 billion kw·h in 2020,among which the energy consumption of data center air conditioning system accounts for about 40% of the total energy consumption.Therefore,how to reduce the energy consumption of refrigeration system is the key to the development of energy saving in data.There is a large amount of low enthalpy air outside in winter and transition season.It is an important means of energy saving and consumption reduction for air conditioning system of data center to make the best use of natural cold source by natural cooling technology and reduce the use of water chillers throughout the year.Researchers at home and abroad have done a lot of research on the natural cooling technology of data center,but there are many factors that affect the energy saving of the system.For the refrigeration system,each factor will affect each other,so it is difficult to achieve the energy saving of the system only by optimizing a certain equipment or operating parameters.In this context,this paper takes a data center of Beijing Mobile as the research object,aiming at the cooling tower + plate exchange indirect natural cooling system,through the software TRNSYS As a system simulation platform,energy-saving analysis,control strategy formulation of natural cooling system,operation parameter design optimization of different refrigeration modes and design optimization of group control system of chiller are studied from the overall system.First of all,the load characteristics and air-conditioning equipment characteristics of the data center are described,and a complete energy consumption model of the terminal machine room and the mathematical model of each equipment of the system are established.On this basis,the global control system of data center refrigeration mode switching control strategy,precision air conditioning variable air volume control strategy,chilled water constant temperature difference control strategy,cooling tower constant outlet water temperature control strategy and chiller group control strategy are compiled.Finally,TRNSYS 17 is used to build the simulation platform of natural cooling system of data center cooling tower.Secondly,according to the data center design code gb50174-2017 on the data center refrigeration system environmental requirements,the system simulation parameters are selected.Through the simulation platform,the influence of different parameters on the system operation control and energy consumption is explored from the overall system,including cabinet air supply temperature,chilled water supply and return water temperature and cooling tower outlet water temperature.The energy consumption of the terminal precision airconditioner is mainly determined by the difference between the air supply temperature of the cabinet and the water supply temperature of the chilled water.At the same time,the water supply temperature of the chilled water also determines the energy consumption of the chiller and the natural cooling time of the whole year.After comprehensive comparison,when the air supply temperature of the cabinet is 23 ?,the water supply temperature of the chilled water is 16 ?,the system operates optimally in the whole year.At the same time,according to the different cooling modes of the system,optimize the cooling tower outlet water temperature control strategy,and put forward the 14.5 ? constant temperature control strategy in the complete natural cooling mode.In the mixed refrigeration mode and mechanical refrigeration mode,the constant temperature difference VAV control mode is adopted,which is 4 ? higher than the outdoor chamber ball temperature.Finally,the data center cooling tower natural cooling system global optimal condition parameter settings are obtained,and the energy-saving potential ranking of five typical cities in the national building climate area under the above optimal control mode is analyzed: Harbin > Xi'an >Shanghai > Dali > Haikou.Finally,in order to ensure the real-time operation efficiency of chillers and reduce the energy consumption of chillers under partial load.In this paper,three refrigeration load conditions are established according to the use of the end frame.According to the different load distribution modes,three group control strategies are established,i.e.start and stop one by one,load sharing one by one and optimal load distribution based on COP.By comparing the operation energy consumption of three group control strategies under different load distribution,the control strategy mode with the lowest energy consumption under different load distribution is obtained,and the data center is established The optimal group control strategy of chiller.So as to improve the efficiency of the chiller and reduce the energy consumption of the whole system. |
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