地铁隧道悬臂掘进法新型抑尘装置性能研究

Research on the performance of a new type of dust suppression device for cantilever excavation of subway tunnels

为解决中心城区地铁隧道掘进粉尘质量浓度严重超标问题,讨论了一种掘进机新型端头U形抑尘装置并对其相关参数开展研究;通过现场采样并分析采样粉尘的粒度分布,基于粒度分布分析喷嘴适用性;结合数值模拟软件CFD分析风流场和不同供水压力下液滴速度和粒径对雾滴场的影响;通过现场应用测试掘进机新型端头U形抑尘装置抑尘性能.研究结果表明:当喷雾压力为6 MPa和8 MPa时,大多数液滴在优质抑尘速度25 m/s左右;当喷嘴数量为11个,喷雾压力为6 MPa时,所形成的高浓度雾滴场包裹性最好;在6 MPa的喷雾压力下,优质液滴粒径占比89%以上,雾滴粒径分布更均匀,抑尘性能更好;通过现场应用,最大总尘抑尘效率可达81.55%,最大呼吸性粉尘的抑尘效率可达80.24%,其他测点的抑尘效率仍可达71.21%以上,抑尘效果明显.

In order to solve the problem of excessive dust concentration in subway tunnel driving in central urban area,this study discusses a new type of u-shaped dust suppression device at the end of tunneling machine and studies its related parameters.The applicability of nozzle was analyzed based on the particle size distribution of sampled dust by field sampling.The influence of droplet velocity and particle size on droplet field under air flow field and different water supply pressure was analyzed with CFD.Finally,the dust suppression performance of u-shaped dust suppression device at the new end of roadheader is tested by field application.The results show that when the spray pressure is 6 MPa and 8 MPa,most droplet is about 25 m/s.When the number of nozzles is 11 and the spray pressure is 6 MPa,the encapsulation of the formed high-concentration droplet field is the best.Under the spraying pressure of 6 MPa,the particle size of high-quality droplets accounted for more than 89%,and the particle size distribution of droplets was more uniform,and the dust suppression performance was better.Through field application,the maximum dust suppression efficiency can reach 81.55%,and the maximum respirable dust suppression efficiency can reach 80.24%.The dust suppression efficiency of other measuring points can still reach more than 71.21%,indicating obvious dust suppression effect.