寒区隧道电热膜加热保温技术研究

Study on Electric Film Heating and Thermal Insulation Technology for Tunnels in Cold Regions

针对我国寒区隧道冻害问题,以吉林省东南里隧道为例,通过现场温度实测和数值模拟,分析保温层的设防长度、设置厚度和适应范围,并提出寒区隧道电热膜加热保温系统。采用等效厚度法,给出保温层厚度的计算方法和保温层变截面厚度的设置方法。结果表明:被动保温措施保温层法具有一定的温度适应性,当隧道外界气温低于-18.5℃时,应考虑其他主动保温措施;寒区隧道电热膜加热保温系统基于主动保温设计理念,通过温度感应计精准定位冻害的发生位置,进而启动加热膜工作,为寒区隧道保温技术提供了新方法。

In view of the problem of frost damage of tunnels in cold regions in China,taking Dongnanli Tunnel in Jilin province as an example,the fortification length,thickness,and application scope of thermal insulation layer were analyzed through on-site temperature measurement and numerical simulation. Meanwhile,an electric film heating and thermal insulation system was proposed. The calculation method of the thickness of the thermal insulation layer and the setting method of the thickness of the variable cross-section of the thermal insulation layer were also proposed by using the equivalent thickness method. The results show that the passive thermal insulation method has a certain temperature adaptability,and other active thermal insulation measures should be considered when the temperature outside the tunnel is lower than -18.5 ℃. Electric film heating and thermal insulation system for tunnels in cold region adopts the design concept of ’Active Thermal Insulation’. The problem of tunnel frost damage is solved by accurately locating the position of the frost damage and starting the heating film work consequently. This provides a new method for tunnel thermal insulation technology in cold regions.