A method of rapid determination of gas pressure in a coal seam based on the advantages of gas spherical flow field

Against the problem of calculating gas content rapidly, this article studied the desorption characteristics of coal by measuring the characteristic parameters of coal in the laboratory. With the actually measured amount of desorption and the desorption rule of the coal within the first 30min, through theoretical derivation and Multiple Linear Regression, the gas content desorbs within the first 120min and the residual amount after a 120min of coal desorption is studied and confirmed Based on the rapid determination model of gas content in the coal seam is established, and the new model is verified, whose accuracy rate reaches above 85%. If relevant electronic equipments were made, this method would be able to give a result within 40min, thereby realizing the rapid determination of gas content in the coal seam within the gas belt.

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Verification of Rapid Determination of Coal Seam Permeability Coefficient Based on COMSOL

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/647/1/012063 ◽

2021 ◽

Vol 647 ◽

pp. 012063

Author(s):

Li Bingrui ◽

Li Shubo

Keyword(s):

Coal Seam ◽

Permeability Coefficient ◽

Rapid Determination

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Calculation of permeability coefficient of coal seam under rapid measurement conditions

E3S Web of Conferences ◽

10.1051/e3sconf/201913604004 ◽

2019 ◽

Vol 136 ◽

pp. 04004

Author(s):

Manzheng Yang ◽

Bingrui Li ◽

Shubo Li

Keyword(s):

Coal Seam ◽

Permeability Coefficient ◽

Integral Transformation ◽

Gas Permeability ◽

Rapid Determination ◽

Flow State ◽

Time Curve ◽

Pressure Time ◽

The Relationship

In order to achieve rapid determination of coal seam permeability, the calculation method of coal seam permeability coefficient was studied. Based on the Darcy's law in the flow of gas in the coal seam, the relationship equation between the gas pressure of the borehole and the gas permeability coefficient of the coal seam is established under the radial unsteady flow state. The gas permeability coefficient of the coal seam is obtained by coordinate transformation and integral transformation. Solve the expression. The analysis and verification of the field measured data show that the expression of the analytical solution of the coal seam permeability coefficient is consistent with the variation of the borehole pressure-time curve, which can provide a theoretical basis for the rapid determination of coal seam permeability.

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Active pressure determination under the condition of rapid determination of gas pressure

Progress in Mine Safety Science and Engineering II ◽

10.1201/b16606-47 ◽

2014 ◽

pp. 249-252

Author(s):

Shu Yang ◽

Genyin Cheng ◽

Liming Qi

Keyword(s):

Rapid Determination ◽

Gas Pressure ◽

Active Pressure

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Weak Beam Imaging and Diffraction Studies of Stacking Faults in Silicon

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100092918 ◽

1976 ◽

Vol 34 ◽

pp. 590-591

Author(s):

T. Y. Tan ◽

W. K. Tice

Keyword(s):

Fast Neutron ◽

Rapid Determination ◽

Stacking Faults ◽

Imaging Method ◽

Large Reduction ◽

Dislocation Loops ◽

Fringe Spacing ◽

Weak Beam ◽

Kinematical Theory

In studying ion implanted semiconductors and fast neutron irradiated metals, the need for characterizing small dislocation loops having diameters of a few hundred angstrom units usually arises. The weak beam imaging method is a powerful technique for analyzing these loops. Because of the large reduction in stacking fault (SF) fringe spacing at large sg, this method allows for a rapid determination of whether the loop is faulted, and, hence, whether it is a perfect or a Frank partial loop. This method was first used by Bicknell to image small faulted loops in boron implanted silicon. He explained the fringe spacing by kinematical theory, i.e., ≃l/(Sg) in the fault fringe in depth oscillation. The fault image contrast formation mechanism is, however, really more complicated.

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