运营通风作用下高海拔隧道保温隔热层的设计参数

为研究运营通风作用下高海拔隧道的保温隔热层的设计参数,通过建立考虑气-固耦合换热的隧道有限元模型,研究了不同通风工况下的气流流动特征,分析了保温隔热层的合理敷设长度。结果表明:在不同的通风工况下,隧道内气流流动特征不同;平导压入通风时,在横通道和主洞相接处出现漩涡;自然通风下,二衬表面温度在洞口段骤然升高,而后趋稳;建议主洞进出口保温层的敷设长度为565 m,导洞进出口保温层的敷设长度为680 m。

Design Parameters of Thermal Insulation Layer for High-altitude Tunnel Under Operational Ventilation

In order to study the design parameters of thermal insulation layer for high-altitude tunnel under operational ventilation,by establishing a finite element model of the tunnel considering the gas-solid coupling heat transfer,the characteristics of airflow under different ventilation conditions were studied,and the reasonable length of the thermal insulation layer was analyzed.The results show that the characteristics of airflow in the tunnel are different under various ventilation conditions;when the air is pushed through the parallel pilot tunnel,a vortex appears at the junction of the transverse channel and the main tunnel;under natural ventilation,the surface temperature of the secondary lining suddenly increases at the entrance of the tunnel and then stabilizes.It is recommended that the length of the thermal insulation layer for the entrance and exit of the main tunnel be 565 m,and the length of the thermal insulation layer for the entrance and exit of the pilot tunnel be 680 m.