Study On Optimization Of Ventilation System And Utilization Of Natural Wind In Extra-long Highway Tunnel

The ventilation system has the characteristics of large scale,high cost and high energy consumption,so the choice of ventilation scheme is the direct factor that affects the construction difficulty and the construction investment.This paper is based on the Manyue tunnel,which researches on tunnel ventilation construction mode,operation ventilation scheme,disaster relief and natural wind utilization of extra long highway tunnel,and puts forward reasonable ventilation scheme and mechanical configuration,and draws on the design and control of tunnel ventilation and disaster prevention and rescue ventilation beneficial conclusions.The main contents of this paper are as follows:(1)For the six initial ventilation schemes of Manyue tunnel,the calculation of supply and exhaust volume,the power required for axial fan,the quantity of jet fan and energy consumption during operation is completed.The optimal scheme is determined by general comparison of economy,ventilation,disaster relief and construction difficulty.(2)For the optimal ventilation scheme,the economic analysis of the wind shaft under different air exhaust ratio and different wind speed is carried out to determine the economic exhaust ratio of the ventilation shaft.On the basis of the orthogonal test method,the civil construction cost,Configuration cost and energy consumption cost,comprehensive analysis of wind economic area and economic wind speed.Combined with civil construction costs,electromechanical configuration costs and energy costs,comprehensive analysis of wind economic area and economic wind speed.(3)Combined with domestic and foreign regulations related to underground ventilation,the optimal setting of the operating ventilation jet fan was carried out by diluting the pollutant concentration.It is concluded that the tunnel jet fan can be set up in stages according to the number of disaster relief facilities.(4)According to the tunnel vertical shaft setting and horizontal channel distribution,put forward the disaster prevention and rescue ventilation scheme in different places when the fire occurred.Based on the theory of ventilation network and the calculation program of ventilation network,the situation of different fire locations in the tunnel is calculated,and put forward a reasonable fan opening program and tunnel disaster prevention fan configuration.(5)Based on the theory of ventilation network,the influence of the thermal difference on the airflow in the tunnel is calculated and calculated in different seasons.Considering the influence of traffic wind,thermal difference and natural wind pressure,calculate the airflow in the tunnel when the jet fan is opened at different positions,and explore how to use the natural wind more effectively.