Research On Soil Auxiliary Cooling And Waste Heat Recovery Heating Technology For Cold Land Data Center

In recent years,with the rapid development of information technology such as 5G,big data,and AI intelligence,the demand for data application has shown explosive growth.In February 2022,China officially launched the "East Data West Computing" project,and the construction of a new generation of data center has entered an accelerated period.The rapid development of data centers also brings huge energy consumption.Energy consumption of IT equipment accounts for 45% of the total energy consumption of data centers,and this part of electricity is basically converted into heat and discharged into the air,which is directly wasted.Therefore,under the goal of carbon peak and carbon neutrality,the use of efficient cooling and waste heat utilization technology is an effective scheme to improve the energy efficiency level of facilities,and the construction of energy-saving,efficient and lowcarbon data centers has become an inevitable trend in the current development.The shallow soil source in the severe cold area has the characteristics of low temperature and strong stability,which can be used as a cold source to assist the cooling of the data center and as a heat accumulator to store the waste heat of the computer room.It can also be heated by ground source heat pumps.Therefore,by studying a data center in Harbin,this paper carried out energy-saving transformation according to its existing cooling tower refrigeration system,innovatively coupled the refrigeration system with soil source,constructed soil-assisted refrigeration and waste heat recovery heating system of data center in cold region,and realized the utilization of waste heat in the whole period of the data center.The software TRNSYS was used to construct the system simulation model.Compared with the traditional mechanical refrigeration system,the energy consumption and energy saving effect were analyzed,and the waste heat recovery potential and economy were analyzed.Firstly,through the construction of data center model to analyze the annual dynamic load characteristics of the computer room and establish a perfect mathematical model of refrigeration equipment.TRNSYS software was used to construct a simulation platform for soil-assisted refrigeration and waste heat recovery heating system in data centers.Secondly,the energy consumption and energy saving of the traditional data center mechanical refrigeration system,the existing cooling tower refrigeration system and the soil-assisted refrigeration system were compared and analyzed.The PUE of the soil-assisted refrigeration system was 1.30,which was 2.2% lower than that of the cooling tower refrigeration system and 7.1% lower than that of the traditional mechanical refrigeration system.Parameter optimization was carried out with the system energy consumption as the objective function.It was determined that when the stable temperature of the machine room was 24℃ and the operation mode switching temperature was 8℃,the soil assisted refrigeration and waste heat recovery system reached the highest annual energy saving compared with the cooling tower system,and the annual energy saving was 4420 tons of standard coal.According to the standard coal unit price of 500 yuan per ton,the annual saving income was about 2.21 million yuan.When the air supply temperature of the machine room is 18℃ and the freezing water temperature is 11℃,the system energy consumption is the lowest,so as to determine the best operating state of the soil assisted refrigeration and waste heat recovery system in the data center.At the optimal operating state of the system,the annual operating temperature of the soil source temperature increased by about 0.03℃,which basically reached the soil thermal balance and could fully meet the long-term operation of the system.Finally,the data center realizes the utilization of waste heat in the whole period through the system,and the waste heat recovery is 88 GWh,which is equivalent to saving 10,800 tons of standard coal per year.Combined with natural regeneration heat from soil source,113.7GWh heat could be provided for heating.The annual cost method was used to analyze the data center soil assisted refrigeration and waste heat recovery heating system,although the initial investment was high,but the annual cost was 13.148 million yuan,22.7% lower than the traditional mechanical system.The heating income of waste heat recovery is18.4194 million yuan,which can recover the initial investment cost in about 2 years.