Study Of The Simulation For Cooling System Using Lake Water Source In Data Center Based On Trnsys

At present,China is about to enter the era of big data and cloud computing.The amount of business in fields of mobile Internet,Internet of Things,and cloud computing continues to grow,making the demand for data centers increasing.In 2016,the total market size of China's data center has reached 71.45 billion yuan.In the data center,a large number of IT equipment such as servers are arranged.Semiconductor,the core component,is a high-heating one in servers that requires a large amount of cooling to maintain the thermal environment of the engine room,resulting in energy consumption of the cooling system that is 25 to 30 times that of ordinary public buildings.At the same time,with the rapid development of IT technology,the power density of the CPU is also growing,and then the degree of heat density in the data center is rising.Therefore,energy-saving and emission-reduction of data centers are imperative.Free cooling technology greatly reduces the operating time of chillers through the use of natural cooling sources,and improves the energy efficiency of data centers.It is an efficient solution that received widespread attention.The object in this paper is the natural cooling system with lake water as cooling resource in the data center.This paper has compared the energy saving effect of the lake water natural cooling system?LW-NCS?with that of the traditional mechanical cooling system and the cooling tower system respectively,and further optimized the operation of LW-NCS with the goal of minimizing energy consumption.First,three simulation cooling system with different cooling resource were built.Modules in the cooling system such as chiller,cooling tower,refrigerating pump,cooling pump,lake water pump,plate heat exchanger were established.At the same time,control modules and auxiliary modules were also added in the system.All processes were completed using software Trnsys.Second,the energy saving rate of lake water cooling system was analyzed by using simulation platform.Results showed that the energy saving rate of LW-NCS was38.6%and 34.7%lower than the traditional mechanical refrigeration system and cooling tower system,respectively.The power usage efficiency?PUE?of data center with LW-NCS was 1.23,which was a great improvement compared with the traditional mechanical refrigeration system?PUE=1.34?.Finally,the effect of operating parameters on the energy distribution of LW-NCS was analyzed in the simulations.The optimal supply air temperature(T_sa)and chilled water temperature(T_chw,s)were determined by energy function.The simulation results showed that the annual energy consumption of LW-NCS decreased first and then increased accordingly with the increase of the set-point of temperature difference between T_sa and T_chw,s,and the energy consumption reached the minimum when the difference value was 7°C.Given the set-point of temperature difference value as 7°C,the T_sa was then selected to determine the optimal parameter of the LW-NCS.Result showed that the optimal T_sa=21°C,and T_chw,s=14°C,when the energy saving rate of LW-NCS was 34.3%and 59.7%lower than non-optimized LW-NCS and the traditional mechanical refrigeration system,respectively.