Research On Ventilation And Comprehensive Energy Conservation Of Subway Tunnel

Metro rail transit system as an important part of urban traffic,and with its advantages of large capacity,high comfort,convenient and quick becomes the ideal solution of modern urban traffic problems.It plays an irreplaceable role in alleviating urban traffic congestion,develops the urban underground space.With the large-scale construction and operation of metro tunnels,the metro system also accounts for a large proportion of the energy demand in big cities.Energy consumption of metro ventilation and environmental control system accounts for about 30% of total metro system energy consumption,so the metro ventilation control system is energy saving or not directly affect the energy consumption of urban rail transit system.Reducing energy consumption of the metro ventilation and environmental control system can not only ease the power shortage in big cities but also reduce the operation cost of the metro.Based on the study of metro tunnel ventilation,this paper puts forward the energy saving operation scheme of metro tunnel heat removal system,and calculates the heat load caused by the leakage of air through the platform screen door?PSD?system.In this paper,the research idea and technical routes,an one-dimensional metro tunnel ventilation model and station tunnel three-dimensional model have been established,through numerical simulation of one-dimensional model and three-dimensional model of,cooperate with metro tunnel ventilation experiments to study the metro tunnel ventilation and comprehensive energy saving.The main research contents of this article are as follows.?1?The ventilation model of Shenzhen metro line 10 was established to study the influence of fan air volume of tunnel exhaust system on the whole air temperature field of the tunnel.In order to ensure that the air temperature of metro tunnel is lower than the operating requirement temperature,the purpose of tunnel ventilation and energy saving is achieved.?2?The local 3d model of station tunnel was established,and the temperature distribution law of the station tunnel was analyzed based on the results of one-dimensional model simulation analysis.The study shows that the air in lower part of the tunnel is not significantly affected by the wheel heating,and the temperature rise is below 3.5k,considering the removal of the track design of the track.At the same time,reasonable air flow volume distribution of tunnel exhaust system is carried out.Without changing the air flow of tunnel exhaust system,reasonable tunnel exhaust system air flow volume distribution can make tunnel average temperature drop for 0.27?,and Achieve better tunnel heat transfer effect.?3?Leakage air volume model of metro PSD system is set up,which is used to study the air exchange between station and tunnel,during the train stops in station and the platform screen doors open.The variation of the leakage flow and air leakage direction of the PSD in different positions of a same metro station is obtained.The research shows that the air leakage of the upper and lower reaches of the platform is higher,and the air leakage of the middle reaches is lower.In addition,the air leakage direction of the upper reaches platform screen doors is from tunnel to station,and the air leakage direction of the lower reaches platform screen doors is from platform to tunnel.?4?This paper studies the influence of different frequency of trains on the air leakage of the PSD to train station,with forward operation mode of the Shenzhen metro line 10.When 27 Trains start per hour,air leakage volume from the tunnel to the platform is 937.25m3,air leakage volume from platform to tunnel is 912.78m3.When 24 Trains start per hour,air leakage volume from the tunnel to the platform is 885.69m3,air leakage volume from platform to tunnel is 875.83m3.When 10 Trains start per hour,air leakage volume from the tunnel to the platform is 863.65m3,air leakage volume from platform to tunnel is 832.10m3.When 6 Trains start per hour,air leakage volume from the tunnel to the platform is 842.41m3,air leakage volume from platform to tunnel is 788.48m².?5?The experimental method is used to measure the change of piston wind speed in metro tunnel and the PSD's air leakage flow.The experimental results are compared with the numerical simulation results which prove the accuracy of the numerical simulation.?6?Based on the comprehensive study of energy saving,in summer operation₁,which the of metro tunnel exhaust fan is 40m3 per second at the flat peak period,and air flow volume is 50m3 at the peak,compared with operation₂,which the of metro tunnel exhaust fan is 50m3 full day,can save power 3223080 KWH,as well as save metro operation cost more than 50 million Yuan during a year.