Study On The Single-Track Tunnel Ventilation Control Method

The traditional ventilation system of railway tunnels is always designed by the Steady flow Theory Model (STM), which leads to many problems, such as the energy consumption is too large, mechanical ventilation can't be operated in some tunnels and automatic control of ventilation system with energy conservation also can't be performed, etc. This paper does some detailed studies on tunnel ventilation control method combined with a tunnel ventilation project.The unsteady .flow theory is used for calculate air flow velocity and one-dimension unsteady convection-diffusion model is used for calculate pollutant concentration (called Unsteady Theory Model in general, UTM), and a new tunnel control method based on UTM and neural network model is developed. First, the difference between the STM and UTM is compared and analyzed. The results show that it can accurately simulate the unsteady flow process of piston wind and the pollutant distribution in tunnel after train left the tunnel, can analyze and calculate the good effect of inertial action of piston wind if using UTM. Then, two aspects of energy conservation in tunnel ventilation system are attained. One is the lessening of pollutant length needed to be removed; the other is using the inertial action of piston wind to remove pollutant. Finally, through simulating many ventilation conditions, a new tunnel ventilation control method based on neural network model is developed, which can be used in the field tunnel ventilation project.The tunnel ventilation control method developed here has the good functions of energy saving and automatic control under normal conditions. The type of this control method is simple and it has a wide application.