Analysis of Influencing Factors on the Temperature Field in High Geothermal Railway Tunnel
Conventional tunnel cooling load prediction methods are inadequate for the high geothermal extreme conditions of the Sichuan-Tibet Railway tunnels,creating an urgent need for new predictive methods and research.Using the Sejila Mountain Tunnel of the Sichuan-Tibet Railway as a case study,a thermal-humidity coupled porous medium model was developed to assess the effects of surrounding rock seepage water,insulation layer,and air supply velocity and temperature on the tunnel temperature field.The insulation layer significantly lowers the tunnel air temperature.The effective ventilation distance increases by 5.87%in tunnels with water-containing surrounding rock and by 25.51%in tunnels with solid surrounding rock.Increasing the insulation layer's thickness does not significantly lower the tunnel temperature;however,the surrounding rock temperature and air supply velocity have a considerable impact on it.The surrounding rock temperature sets the upper limit for tunnel temperature.When the air supply speed increases from 1 m/s to 2 m/s or 3 m/s,the tunnel temperature decreases by 20.53%or 24.83%,respectively.The factors influencing the intensity of the tunnel temperature field,in order of impact,are surrounding rock temperature,air supply speed,air supply temperature,and insulation layer thickness.The surrounding rock temperature sets the upper temperature limit and affects the cooling challenge of the tunnel.Increasing the insulation layer's thickness has little effect,while the air supply velocity can significantly reduce the tunnel temperature.
high geothermal railway tunnelheat and humidity couplingporous mediumtemperature field distributionsensitivity analysis
万方数据
维普
