Creation of Thermal Environment around Construction Tunnel Trolley and Optimization of Exhaust Angle for Recirculated Air
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 es-tablished,furthermore,six different flow angles are supposed such as 0°,15°,30°,45°,60°,75°.Numerical calculation is car-ried out based on the above model.The temperature-velocity field data of 5 sections of the secondary lining trolley are ana-lyzed.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 effi-ciency 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 exam-pled of 60°,the peak of a temperature decreasing is approximately 1.5℃.But the wind speed decreases at 75°,and this de-crease 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 construc-tion to the maximum extent,and protects the occupational health and safety of construction personnel.The above analysis re-sults provide quantitative reference for iterative optimization of wet air purifier.
construction tunnelcreation of local environmentalsomatosensory temperatureoutflow anglenumerical sim-ulation
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万方数据
