Calculation And Simulation Of Thermal Potential Difference In Inclined Shaft Of Highway Tunnel

In order to effectively reduce the cost of ventilation in highway tunnel operation,people began to study the supplement effect of natural resources on tunnel mechanical ventilation,in which the use of natural wind is an important part.The natural wind in the tunnel is caused by the natural wind pressure.The natural wind pressure mainly includes three parts: thermal potential difference,overpressure difference and wind wall pressure difference.In the highway tunnel with vertical(inclined)well,the thermal potential difference at the vertical(inclined)well is the main part of the tunnel natural wind utilization.At present,there are few research results on the utilization of the thermal potential difference of the vertical(inclined)well in the tunnel,and the utilization rate of the natural wind in the tunnel is relatively low.Therefore,in order to so as to effectively utilize the natural wind,it is necessary to study the effect of the thermal potential difference of the vertical(inclined)well of the highway tunnel.Based on the application background of the East Tianshan tunnel in Xinjiang,this paper analyzes the variation law of the thermal potential difference of the inclined shaft of the tunnel with the methods of data collection,theoretical calculation and numerical simulation,and carries out the following research:1.The numerical simulation of single inclined shaft tunnel is carried out by using fluent simulation software.The distribution of density field,pressure field and wind speed field in inclined shaft under different ambient temperatures is analyzed.It is concluded that in winter,the inclined shaft of the tunnel is in the centralized ventilation mode,in summer,the inclined shaft of the tunnel is in the centralized ventilation mode,but the natural wind speed in the exhaust state is far greater than that in the air supply state.2.Set the natural wind speed in the air supply inclined shaft,calculate the natural wind volume under the single inclined shaft of the tunnel under different environmental wind speed by fluent simulation software,analyze the density field,pressure field and wind speed field distribution in the inclined shaft under different environmental temperature and wind speed,and summarize the change rule of natural wind speed with the change of environmental temperature.3.Based on the ventilation calculation of single inclined shaft tunnel,the ventilation model of double inclined shaft tunnel is established,and the distribution of density field,pressure field and wind speed field in the inclined shaft under different ambient temperature and different wind speed is analyzed.This paper summarizes the organization model of the air flow in the double inclined shaft tunnel under different air velocity,and obtains the change rule of the average internal wind velocity of the double inclined shaft tunnel with the ambient temperature and air velocity.4.According to the predicted traffic volume of the tunnel,the air demand of the East Tianshan tunnel is calculated,and the tunnel ventilation scheme based on the use of inclined shaft thermal potential difference is proposed,and the energy-saving effect of the tunnel under this ventilation mode is calculated.