Research On Waste Heat Recovery And Utilization Of Data Center Based On Heat Pump Technology

In recent years,with the development of the Internet industry,people’s demand for data processing,transmission and storage is increasing,which promotes the rapid development of the data center industry.While data centers consume a lot of electricity,they also generate a lot of heat.The waste heat recovery and utilization of low grade heat generated by data centers is also getting more and more attention.Based on the cooling system of a data center in Beijing,this paper uses Aspen Plus software to build a simulation model to simulate the operating conditions of the cooling system before and after waste heat utilization,and analyzes the influence of outdoor wet bulb temperature on both.The main tasks include:1.According to the actual refrigeration system of a data center in Beijing,two waste heat recovery systems of chilled water heating and cooling water heating were designed,and three working modes of the two systems(including natural cooling mode,mechanical refrigeration mode and the composite mode of natural cooling and mechanical refrigeration,hereinafter referred to as composite mode)were established by Aspen Plus respectively.2.During the simulation,the isentropic efficiency of the compressor and the pump efficiency of the pump are set to remain unchanged,and the parameters under nominal working conditions are adopted for both.According to the actual operating parameters of the cooling tower,the relationship curve between the water outlet temperature of the cooling tower and the outdoor wet bulb temperature was determined,and the conversion temperature of the three operating modes of the cooling system was further calculated,which were corresponding to the outdoor wet bulb temperature of 6.07℃ and 10.88℃ respectively.3.In the simulation of waste heat recovery system,different working medium and different heat extraction methods are simulated respectively.The simulation results show that COP of natural cooling mode is 10.42.The circulating flow of chilled water pump and cooling water pump is less affected by the outdoor wet bulb temperature,but the pump power changes dramatically when the working mode is changed because of the circulating resistance.In some outdoor wet bulb temperature ranges,the energy consumption of the combined mode is higher than that of the mechanical refrigeration mode at similar temperatures.In order to reduce energy consumption,its working mode is changed and simulated again.4.The simulation results of cooling water heating are analyzed,and the results show that the energy consumption of the mechanical refrigeration mode is lower than that of the composite mode when the outdoor wet bulb temperature is 9.28℃and 10.35℃,respectively,by 5.06%and 10.89%.When the outdoor wet bulb temperature is 8.21℃,the energy consumption of the two operating modes of the system is similar.Therefore,the above three conditions are adjusted to mechanical refrigeration mode.5.Finally,the annual operation effect of waste heat recovery system in data centers in different cities is calculated.Using the hourly meteorological parameters of 6 different cities derived from DeST,the running time of three working modes of data centers in different cities was calculated and analyzed,and the energy consumed and heat obtained by the waste heat recovery system of different working medium in a standard year was calculated.The results show that for the data center whose heat dissipation(IT equipment power)is 9142kW,the annual residual heat obtained by different heating methods,different working media and waste heat recovery systems in different cities is more than 10 million kW·h.