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摘要: 使用常规X射线或CT扫描进行图像处理，研究裂隙结构时，主裂隙不易提取，其特征不明显，不能直接反映主裂隙构造与流体速度关系。运用高清相机拍摄井下煤壁X形真实裂隙进行数字化处理，并运用AutoCAD软件提取裂隙特征，将图片矢量化导入Comsol Mutiphysics仿真模拟软件进行计算，模拟得到瓦斯分布压力场和渗流速度场云图。结果表明：含X形裂隙煤样中，瓦斯自入口开始，渗流压力从左至右递减，裂隙通道内瓦斯压力均匀分布，是一段压力缓冲区；非裂隙区渗流速度场分布不均匀，X形裂隙支流处较汇流处瓦斯渗流更为活跃，瓦斯的流向和裂隙走向的夹角对渗流速度有明显的影响，瓦斯自下边界流入时的最大渗流速度是自左边界流入的29.5倍；裂隙通道内的渗流速度与裂隙的尺度成单调递减对数函数关系，裂缝尺度越大，达西渗流速度越低，当裂隙尺度为0.68~1.23 mm时对渗流速度影响最明显。研究成果可直观地了解煤裂隙内瓦斯渗流特征。Abstract: In theudy of fracture structure, the image processing with conventional X-ray or CT scanning will be accompanied by a large number of secondary fractures, and the main fracture characteristics are not obvious, which can not directly reflect the relationship between fracture structure and fluid velocity. High definition camera is used to take X-shaped real cracks in coal wall for digital processing, and the characteristics of fractures are extracted by CAD software, and the images are vectorized into the model, the distribution nephogram of seepage velocity field and seepage pressure field is obtained by simulating software. The results show that from the entrance, the seepage pressure decreases from the left to the right, are evenly distributed in the fracture channels, the fracture area fully releases the pressure, which is a pressure buffer zone; the distribution of seepage velocity field in the rock mass is uneven, the seepage in the tributary area is more active than that in the confluence area, and the angle between the gas flow direction and the fracture direction has obvious influence on the seepage velocity. The maximum seepage velocity of gas in the same flow direction is 29.5 times. There is a logarithmic function relationship between the seepage velocity in the fracture channel and the fracture size. When the fracture size is 0.68-1.23 mm, the seepage velocity is most obvious. The research results could be used to understand the characteristic of gas seepage flow in coal fractures intuitively.
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Keywords:
- X shape crack /
- gas seepage /
- numerical simulation /
- digital image recognition /
- slit channel
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