Numerical Simulation Of Tunnel Ventilation And Spray Cooling With High Temperature Wall

With the development of the railway construction, the need to build more and more tunnels,and the depth of the tunnel is increasing. Because of the increased exploitation depth and other heat source’s exothermic function, high temperature heat-harm has become a outstanding problem which restrict the safety production.There is only one outlet in heading face which can’t form circle-air flow naturally, so the heat-harm problem has beclom seriously. Ventilation is an effective and economical measurement,and reasonable ventilation system can save costs. Based on GaoLi Gongshan tunnelwith high temperature and deep buried,with method of numerical simulation the influence factor of forced ventilation field distribution analyzed.The mainly contents are as following:(1) The study on theoretical analysis and mathematical model of working face flow.From the basic principle of mass conservation, momentum conservation and energy conservation which under turbulent state carried on theoretical analysis of air flowing rules and established mathematical model.(2) Coupled with the surrounding rock heat transfer ventilation tunneling non-steady-state simulation, the results show that:the tunnel wall temperature decreases gradually with the increase of ventilation time, so the high wall temperature tunneling ventilation surrounding rock heat calculation of the amount of constant wall temperature conditions, in some extents, this calculation is the safe side. When the ventilation time of exit of the tunnel temperature increases, it gradually reduced, and this trend through a stage decreases after a certain time, while in the corresponding stage of the tunnel exit, the average temperature change is small, and the tunnel wall with romantic breaks, the heat has been stable, so the ventilation calculation can be carried out by steady-state calculation.(3) The numerical simulation and analysis are carried on heading face tunnel. Analyzed the five influence factors of heading face jet ventilation.According the numerical of field situation and evaluate results,the influence parameter of different air supply method, different air temperature, different air supply distances, different air supply velocity were carried on.(4) The research of thermal disater prevention technology. According to the numerical simulation result knew that high-thermal temperature can’t be changed by single ventilation rmethod.So it must need other motheds to control thermal disater. During conventional ventilation conditions, added mist spray, the DPM (discrete phase model) of Fluent was used to simulate the water spary process, and the velocity field and temperature field after water spary were obtained, the simulation results show that: after adding spray, tunnel velocity field is essentially the same, but the temperature was obviously dropped compared it which is without spary,and relative humidity has significantly raised.The results showed that: pressed ventilation in heading face obey restrained wall attached jet law.Under different inlet parameter condiation, jet had different initial energy which made bending level change, from different temperature distribution, it can lead to different human thermal comfort. Spray can significantly reduce the temperature inside the tunnel, thereby improving thermal comfort, can be applied in tunnel ventilation.