地下大型洞库群通风网络建立及竖井通风效应研究

Establishment of a Ventilation Network and the Shaft Ventilation Effect in a Large Underground Cavern Group

大型地下洞库(群)施工通常采取分层开挖方式,其上层施工多采取压入式通风方式;进入中下层开挖后,因其污染源一般要大于上层开挖,必须加大风管与供风量,才能继续维持压入式通风,但受施工通道尺寸限制无法增大或增加风管供风量,导致通风状况恶化。文章依托锦州地下储油洞库的施工通风实例,采用Fluent计算软件并结合现场实况针对竖井通风效应进行研究,并对竖井的直径、位置、深度对通风效果的影响进行深入分析。研究结果表明:竖井直径对洞库的通风有一定的影响,但是通过改变竖井的直径来加强通风的作用是有限的;通风效果与竖井的深度有密切的关系,竖井的最优深度会直接影响到洞库的通风效果,本工程中最佳的竖井深度为70 m;采用竖井口布置轴流风机压入新鲜空气,施工通道(从地面进入洞库的施工运输通道)进口作为污浊空气排出口,能够有序形成良性的大循环通风网络。

Large underground cavern groups are usually built in stages, and forced ventilation is often adopted during construction of the upper part. The air duct and air supply must be improved in order to maintain forced ventilation during construction at the middle and lower parts due to a more serious pollution source compared to the upper part. However, it＇s not feasible to increase the air supply volume that is restricted by the size of the construction adit, which results in deterioration of＂ ventilation conditions. Based on the construction ventilation case of the Jinzhou underground oil storage cavern, the shaft ventilation effect is studied and a further study of the effects of the shaft diameter, location, and depth on construction ventilation is conducted by Fluent calculation software and field measurements. The results show that the shaft diameter has a certain influence on the cavern＇s ventilation, but the effects of ventilation enhancement are limited by changing the shaft diameter; the ventilation effect is closely related to shaft depth, and the optimal shaft depth is 70 m; with the forcing of fresh air by the axial flow fan installed at the shaft mouth and entrance of the construction adit （transportation passage leading to the cavern from the surface） used as an exit for polluted air, an orderly virtuous axial ventilation network could be formed.