Data Center Natural Water Cooling System And Water Environment Impact Study

With the rapid development of communication technologies,the number of data center rooms has increased dramatically.Chinese data center energy consumption is as high as 100 billion kW/year,accounting for 1.8%of the country's industrial electricity consumption,and it is growing at a rate that doubles every two years.The energy consumption of the air conditioning part accounts for about 30%?50%,so reducing the energy consumption of the refrigeration system in the data center room has become a hot spot for scholars at home and abroad.The use of free natural cooling sources to cool the data room is one of the current mainstream energy-saving methods.Water-cooled natural cooling technology refers to the use of a cooling tower or dry-cooler to cool the circulating air of the air-conditioning system when the outdoor wet-bulb temperature is low enough or to directly use outdoor low-temperature natural water sources such as lake water and seawater.When the data center uses natural water sources to cool,it will discharge a large amount of heat into the lake water,thus affecting the temperature distribution of the water in the nearby area,and may even cause certain pollution to the water environment.Therefore,when using natural water sources for cooling,the effect of warm water drainage on the water environment should be fully considered to ensure the safety and feasibility of the natural water source cooling system in the data center.This paper mainly studies the impact of the natural water source cooling system and water environment in the data center,and reveals the impact of the Dongjiang Lake data center on the Xiaodongjiang River waters during the year.The influence degree of the ecological system is analyzed based on the average weekly temperature rise in the surface water environmental standard.First of all,this paper introduces the operation mode of the environmental data center computer room,and using the air conditioning system components in the EnergyPlus based data center cooling system heat transfer model is established,through MATLAB simulation to calculate the annual cooling water discharge parameters of 12 months.The simulation results show that 96 percent(8421h)of the Dongjiang lake data center can be cooled by natural water source.At the same time,it is concluded that the average annual heat exchange capacity is mainly concentrated at 3600kW?3750kW,the average drainage flow velocity is mainly concentrated at 0.7m/s?0.8m/s,and the average drainage temperature is mainly concentrated at 17.5??18.5?.Secondly,the fluid simulation software Fluent was used to simulate the whole the temperature,distribution of Xiaodongjiang in the 12th month of the year,based on the theoretical basis of the two-dimensional k-? two-equation control equation,using the simulation results of the central air-conditioning heat transfer model and the hydrological data monitored by the Dongjiang station as the initial condition and boundary conditions.According to the results of two-dimensional simulations,the affected areas mainly gathered near the discharge outlets and in the downstream waters near the river bank,while there were wide undisturbed natural water temperature channels for the fishes in the waters near the river.The average temperature rise in different months is around 0.6?/m2.According to the summer maximum temperature rise specified in the Environmental Quality Standards for Surface Water,the average temperature rise does not exceed 1?.Therefore,the effect of temperature drainage in the data center of Dongjiang Lake on the temperature rise of the Xiaodongjiang River is met requirements.The water body at the water intake is not affected by the diffusion of temperature at the outlet of the outlet,so there is no phenomenon of secondary backflow of heat.Finally,the influence of temperature drainage of Dongjiang data center on the three-dimensional space of nearby waters in July is studied.Based on the theoretical basis of the three-dimensional k-? two-equation control equation,a rigid cover hypothesis method is adopted for the water surface,and a comprehensive surface heat dissipation coefficient model is adopted.The simulations show that the main reason for the temperature increase of the water body in summer in July is the heat of the incoming air.With the shape of the river,the right bulge suddenly expands due to the cross section of the river,forming a vortex with low velocity and heat accumulation.As a result,the temperature of nearby waters has further increased.However,the effect of warm water drainage on the temperature rise of the water body is very small,and the water temperature stratification is obvious,and the temperature fluctuation of the lower water body is relatively small.