平导压入通风对寒区隧道风温场的影响性研究

The Influence of Parallel Heading Forced Ventilation on the Wind and Temperature Field of Tunnel in Cold Region

为探明平导压入通风方式对高海拔寒区特长公路隧道风向、风速、风压和洞内温度场的影响性,以川藏公路雀儿山隧道为工程依托,通过数值仿真和现场测试,分析了不同通风方式下隧道洞内风场和温度场的分布及变化规律。研究结果表明:气热耦合三维数值计算显示风在横通道与主洞和横通道毗邻区域形成了明显的涡流区,平导洞内风压、风速明显高于主洞;平导压入通风使平导和主洞最低风速分别增加了90%、104.5%;平导压入通风对洞内最高风温影响较小,均在7.8℃~8.2℃左右;考虑通风方式、自然风方向和因山体富热产生的隧道内外温差引起的热压差影响,对高海拔寒区特长公路隧道出入口段的防冻长度等应差别化设计,特别要加强主风向隧道一端主洞、平导和横通道的防冻措施。

In order to find out the influence of the parallel heading forced ventilation modes on the wind direction,wind speed and wind pressure,as well as the temperature field in the tunnel,based on the Que’er Shan tunnel of Sichuan-Tibet highway,through the numerical simulation and field test,the distribution and change rule of the wind field and temperature field in the tunnel with different ventilation modes are analyzed. The results show that: the three-dimensional numerical calculation of air-thermal coupling shows that the wind forms an obvious eddy current area in the area adjacent to the main tunnel and parallel heading,and the wind pressure and wind speed in the parallel heading are significantly higher than those in the main tunnel. Then,the parallel heading forced ventilation increases the minimum wind speed of the parallel heading and the main tunnel by 90% and 104. 5%,respectively. Meanwhile,different ventilation modes have little influence on the maximum wind temperature in the tunnel,all of which are around 7. 8 ℃ ~ 8. 2 ℃ . So,considering the influence of ventilation modes,natural wind direction, and the thermal pressure difference caused by the temperature difference inside and outside the tunnel due to the rich heat of the mountain,the antifreeze length of the entrance and exit section of the long highway tunnel in high altitude and cold area should be designed differently. In particular, the antifreezing measures for main tunnel and parallel heading and transverse walkway affected by the prevailing wind should be strengthened.