铁路隧道内道床机械化清筛作业通风技术

Ventilation Technology for Mechanized Cleaning of Railway Tunnel Ballast Bed

以一座长500 m既有铁路单线隧道为工程依托,对隧道内清筛机组加装射流风机,通过理论推导计算和流体仿真分析,确定与隧道通风要求匹配的射流风机参数。结果表明:隧道内风机组中轴线处最高风速约13.6 m/s,随距风机出口距离加长风速逐渐减小,距风机出口40 m处风速已减少至2.9 m/s;将两组射流风机以间距40 m安装,可形成长距离通风传导,明显改善通风效果。经工程现场测试,清筛机组加装单组射流风机作业3 h,隧道内一氧化碳、氮氧化物、颗粒物浓度分别为18.0、4.6、2.9 mg/m^(3),均符合规范要求。

Based on an existing single railway tunnel with a length of 500 m,a jet fan was installed for the cleaning unit inside the tunnel.Through theoretical derivation calculation and fluid simulation analysis,the jet fan parameters that match the tunnel ventilation requirements were determined.The results show that the maximum wind speed at the central axis of the fan unit in the tunnel is about 13.6 m/s,which gradually decreases as the distance from the fan outlet increases.The wind speed at a distance of 40 m away from the fan outlet has decreased to 2.9 m/s.Installing two sets of jet fans with a spacing of 40 m can form a long distance ventilation conduction,significantly improving the ventilation effect.After on-site testing,it is found that the cleaning unit is equipped with a single jet fan for 3 h,and the concentration of carbon monoxide,nitrogen oxide and particular matter in the tunnel are 18.0,4.6 and 2.9 mg/m^(3)respectively,all comply with the specification requirements.