Investigation Of Heat And Humidity Condition In Single Railway Tunnel

High-speed railway is an important symbol of modern railways. Since the heat emission of trains makes the air temperature of tunnel raise, high speed, high density of train operation can cause the environmental deterioration of the railway tunnel, especially for specialty railway tunnel, the heat accumulation will make tunnel air temperature higher. The environmental deterioration of tunnel will affect the secure operation of the train and the equipments, so the thermal environment simulation of the tunnel is of great significance to the development of railway.This article is the research content of the Doctoral Fund Project "The heat and humidity climate simulation and control method of long high-speed railway tunnel". The transient simulation model of air temperature in tunnel has been built and consummated in this paper for special consideration of the impact of the seepage around the tunnel, the outside temperature of tunnel, the shaft, and the numerical calculation method have been researched. Finite volume method is used when discrete the energy equations, a simulation program for air temperature in tunnel has been developed by the Matlab tool.In the different coefficients of seepage, the air temperature in the single tunnel has been simulated with the program; the analysis reveals that the seepage has a great effect to the air temperature in the tunnel;, the role of seepage can't be ignored on the simulation of thermal environment in the tunnel, especially for the long-term simulation. When the outside temperature is constant, the role of the seepage for the temperature depends on the temperature between the inside of tunnel and the surface of tunnel. For the prediction of the hottest month in summer, three calculation temperature have been used:(1) The ventilation calculation temperature of building; (2) The average temperature of the average temperature in hottest month of the nearly 20 years; (3)The hourly typical meteorological parameters. The air temperature inside the tunnel is simulated; the regularity of the air temperature distribution inside the tunnel is concluded. When the average temperature of the average temperature in hottest month of the nearly 20 years is used for the outside temperature, the maximum temperature inside the tunnel is nearly the same to the temperature as the hourly typical meteorological parameters is used. The program can relatively accurate prediction the maximum temperature inside the tunnel. The article analysises year-round air temperature regularity of temperature and the temperature variation of surrounding rock. In addition, the regularity of the air temperature variation inside the tunnel in the different outside temperature, the velocity of train and the position of the shaft has been researched, some conclusions have been educed. The effects to the temperature inside the tunnel by the different factors have been concluded through the research of the tunnel air temperature model and calculation method. It has been built the foundation and provided the reference for the tunnel ventilation design.