寒区隧道侧吹式空气幕保温系统及模型试验研究

Side-Blow Air Curtain Insulation System and Model Test in Cold-Region Tunnels

冻害问题引起寒区隧道结构出现病害,不利于隧道的通行安全。为预防和控制关山隧道冻害的发生,提出一种新型的寒区隧道侧吹式空气幕保温系统。首先,构建空气幕阻隔效率的控制方程,并优化该系统的主要设计参数;然后,设计并研制空气幕作用下保温装置内空气流场和温度场的试验系统,探究射流角度、射流风速、外界风速与阻隔效率之间的变化规律。试验结果发现:1)空气幕射流角度最优值为55°~75°;2)阻隔效率与外界风速呈反比,与射流风速呈正比;3)侧吹式射流保温系统保温效果良好,可有效预防隧道冻害的发生。

Freezing damage causes tunnel structure diseases in cold regions, which are not conducive to tunnel traffic safety. To prevent and control frost damage in Guanshan tunnel, a new type of side-blow air curtain insulation system for cold-region tunnels is proposed. First, the control equation for air curtain barrier efficiency is established, and the main design parameters of the system are optimized. Next, an experimental system of air-flow and temperature fields in the thermal insulation device under the action of the air curtain is designed and developed, and the variation laws of jet angle, jet wind speed, external wind speed, and barrier efficiency are explored. The experimental results reveal the following:(1) The optimal jet angle of the air curtain is 55° ~75°.(2) The barrier efficiency is inversely proportional to the external wind speed and directly proportional to the jet wind speed.(3) The side-blow air curtain insulation system has a good insulation effect and can effectively prevent the occurrence of tunnel freezing injuries.