施工隧道台车周边热环境营造与回用风出流角优化

Creation of Thermal Environment around Construction Tunnel Trolley and Optimization of Exhaust Angle for Recirculated Air

为改善施工隧道二衬台车周边热环境,将湿式空气净化装置应用于天巴高速公路拾贰坡隧道。围绕装置回用风高效利用问题,以拾贰坡隧道为工程原型,利用Fluent软件建立了0°、15°、30°、45°、60°、75°6种不同出流角的混合式通风计算流体力学模型。基于上述模型进行了数值模拟计算,抽取出二衬台车工作段5个切面的温度—速度场数据,进一步引入体感温度公式作为评价指标,量化出流角变化对台车工作区域速度—温度场的影响,优选了回用风出流角。研究结果表明:出流角过小导致流场紊乱,致使回用风效率降低,不利于环境营造;增大出流角至30°以上时,回用风利用效率明显提高,风速大幅上升,温度出现下降;至45°时,回用风有效利用率接近极限,但降温效果仍随着角度增大而提升;至60°时,降温效果最佳,降低约1.5℃;至75°时,风速降低,温度升高,体感温度降低趋势逆转而升高。结合实测数据,发现回用风出流角为60°时,可最大限度改善隧道施工热环境,保障施工人员职业健康安全。上述分析结果为湿式空气净化装置迭代优化提供了量化参考。

In order to improve the thermal environment around the secondary lining trolley of the construction tunnel,the wet air purification device is applied to the Shierpo Tunnel of Tianba Expressway.The efficient utilization of device reuse air is concerned.Shierpo Tunnel is taken as engineering prototype,and a hybrid ventilation computational fluid dynamics model is established,furthermore,six different flow angles are supposed such as 0°,15°,30°,45°,60°,75°.Numerical calculation is carried out based on the above model.The temperature-velocity field data of 5 sections of the secondary lining trolley are analyzed.In order to analyze those numerical data,the somatosensory temperature formula is introduced as the evaluation index,for the sake of the outflow angle change affecting on the velocity-temperature field,and optimization of the reuse air outflow angle.The results show that:the small outflow angle leads to the disordered flow field,which reduces the efficiency of the reuse airflow and is not conducive to the environment construction.When the outflow angle is increased to more than 30°,the utilization efficiency of the reuse airflow is improved as the wind speed is greatly increased and the temperature is decreased.As the angle 45°,the effective utilization rate of reused air is close to its limit.The cooling effect increases as the angle increases.For exampled of 60°,the peak of a temperature decreasing is approximately 1.5℃.But the wind speed decreases at 75°,and this decrease leads to an increase in temperature and rebound of somatosensory temperature.According to the measured data,it is found that the optimal reuse air outlet angle should be 60°.This angle can improve the thermal environment of tunnel construction to the maximum extent,and protects the occupational health and safety of construction personnel.The above analysis results provide quantitative reference for iterative optimization of wet air purifier.