The Thermal-Fluent-Solid Coupling Numerical Simulation Study of Coal and Rock Containing Gas

2014 ◽  
Vol 1010-1012 ◽  
pp. 1498-1501
Author(s):  
Tao Qin ◽  
Yong Li Liu ◽  
Kai Yun Zhang
Keyword(s):  
Numerical Simulation ◽  
Temperature Change ◽  
Simulation Study ◽  
Viscosity Coefficient ◽  
Gas Pressure ◽  
Seepage Velocity ◽  
Gas Concentration ◽  
Working Face ◽  
Gas Seepage ◽  
The Face

COMSOL software was used in the paper for numerical simulation of excavation face and study stress, gas pressure, the gas seepage velocity, displacement and the change of temperature as well as to the effect of dynamic disaster under different temperature conditions. The results show that the speed of gas pressure to reduce slowed, the gas pressure near the working face gradient increasing with the increase of temperature; the face gas concentration changed not significantly because of the change of temperature under the condition of the temperature change is not big; seepage velocity varies was not obvious under the condition of other conditions don't change, because the viscosity coefficient of the change was not obvious.

Numerical Simulation of Roadway Deformation of Different Cutting Aperture

2013 ◽  
Vol 340 ◽  
pp. 892-895
Author(s):  
Xue Min Gong ◽  
Jia Yong Zhang ◽  
Li Wen Guo
Keyword(s):  
Numerical Simulation ◽  
Simulation Analysis ◽  
Wall Rock ◽  
Rock Stress ◽  
Analysis Software ◽  
Pressure Relief ◽  
Element Analysis ◽  
Gas Seepage ◽  
The Face ◽  
Roadway Deformation

Using ANSYS finite element analysis software, the crushing effect and wall rock deformation of a small high-pressure jet impacting coal were given numerical simulation analysis. It verified that impacting increased exposed area of coal in punch, providing conditions for pressure relief of internal coal seam and gas seepage. through comprehensive analysis of the rock stress and coal displacement of different roadway models after undercutting, it was determined that aperture size was 4/15 or so of roadway floor length, thus roadway fissures developed full, and maintained rock integrity, in favor of speeding up the face driving.

scholarly journals Numerical Simulation of Parameters Optimization for Goaf Gas Boreholes

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Jiajia Liu ◽  
Jianliang Gao ◽  
Ming Yang ◽  
Dan Wang ◽  
Liang Wang
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Coal Seam ◽  
Field Application ◽  
Parameters Optimization ◽  
Gas Concentration ◽  
Working Face ◽  
Simulation Results ◽  
Gas Volume

In view of the ground drilling of the N2206 working face in Shanxi Wangzhuang Coal Mine, the gas concentration is low and the extraction effect is not good. Fluent computational fluid dynamics software was used to simulate the ground extraction drilling position of the N2206 working face in the goaf (the distance from the top of the coal seam and the distance from the return to the wind). The numerical simulation results show that when the final hole of the ground extraction hole in the goaf is 16 m from the roof of the coal seam and the distance from the return air is 45 m, the extraction effect is optimal. The average extraction gas volume is 9.78 m3/min, and the average extraction gas concentration is 43.95%, the best extraction effect is obtained. After optimizing the ground drilling position in the goaf and combining with the site implementation, the maximum gas scouring amount of the extraction is 12.59 m3/min, which is 3.42 m3/min higher than the original. The maximum gas concentration of extraction was 63.54%, which was 28.82% higher than the original. After optimization, the gas concentration of the extraction is more than 30%, and the extraction effect is very good. Field application results further validate the reliability of theoretical analysis and numerical simulation results.

scholarly journals Numerical simulation study on gas drainage by interval hydraulic flushing in coal seam working face

2021 ◽  
pp. 014459872110102
Author(s):  
Shengrong Xie ◽  
Junqi Cui ◽  
Dongdong Chen ◽  
Ping Chen
Keyword(s):  
Numerical Simulation ◽  
Coal Seam ◽  
Coal Mine ◽  
Simulation Software ◽  
Gas Pressure ◽  
Gas Extraction ◽  
Gas Drainage ◽  
Drainage Radius ◽  
Working Face ◽  
Effective Drainage

In order to solve the problem of difficult gas extraction in coal mine, a method of gas extraction from coal seam by interval hydraulic flushing is put forward. Based on the coal seam gas occurrence conditions of 7609 working face in Wuyang Coal Mine, the numerical simulation research on gas drainage by ordinary drilling and hydraulic flushing drilling was carried out by using COMSOL numerical simulation software. The results show that with the increase of hydraulic flushing coal quantity, the effective gas drainage radius also increases. The effective extraction radius of ordinary drilling is 0.5 m, and the effective extraction radius is 1.0 m, 1.2 m and 1.3 m respectively when the coal flushing quantity is 0.5t/m, 1.0t/m and 1.5t/m. As multiple boreholes are drained at the same time, the boreholes will affect each other, which will reduce the gas pressure and increase the effective drainage radius, the spacing between boreholes can be greater than twice the effective drainage radius of a single borehole when arranging boreholes. And the smaller the flushing interval, the more uniform the gas pressure reduction area. According to the numerical simulation results, the ordinary drilling and 1.0t/m interval hydraulic flushing test were carried out in the field. Through observation and analysis, the gas concentration of the interval hydraulic flushing drilling module was increased by 31.2% and the drainage purity was increased by 5.77 times compared with the ordinary drilling module. It shows that the interval hydraulic flushing drilling can effectively improve the gas drainage effect.

scholarly journals Influence of Roadway Cross-Section Shape on Gas Explosion Shock Wave Law in U-Type Ventilation Working Faces

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Jiajia Liu ◽  
Mengqi Shen ◽  
Shouqi Chen ◽  
Ming Yang
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
Simulation Study ◽  
Simulation Software ◽  
Effective Length ◽  
Shaanxi Province ◽  
Gas Explosion ◽  
Cross Sectional ◽  
Working Face ◽  
Tunnel Section

In U-shaped ventilation working face, different tunnel section shapes are one of the important factors affecting the propagation of gas explosion shock wave. In order to study the propagation law of gas explosion shock wave in working face, the numerical simulation study was carried out by using Fluent simulation software combined with the actual situation of gas explosion in #415 working face of Chenjiashan Coal Mine in Shaanxi Province. By constructing a three-dimensional mathematical and physical model, a simulation study of the upper-corner gas explosion was carried out. The results are described as follows. (1) After the gas explosion shock wave propagates 40 m, the overpressure peak equidistant difference tends to be stable and attenuates and propagates in the form of a single shock wave. The study determines that the effective length of the U-shaped ventilation inlet/return tunnel is 40 m. (2) When the tunnel section is trapezoidal, the initial overpressure of the gas explosion shock wave propagating to the inlet/return airway is the highest, followed by rectangular and semicircular arches, but the internal overpressure attenuation trend of different cross-sectional shapes is the same. (3) The gas explosion shock wave propagates radially along the working face section during the working face propagation. The farther away the location is from the upper corner of the tunnel during a gas explosion with different cross-sectional shapes, the closer the cutoff overpressure peak is. The attenuation trend of overpressure with the propagation distance conforms to the power function law. The research results provide an important theoretical direction for the numerical simulation of gas explosions in coal mining faces.

Gas Fractal Seepage Properties Research in Soft-Slicing Coal with Triaxial Pressure System

2013 ◽  
Vol 805-806 ◽  
pp. 1494-1501
Author(s):  
Fu Kai Zhang ◽  
Long Jun Xu ◽  
Fen Hua Yue ◽  
Xiao Qin Zhang ◽  
Yu Zhao Feng ◽  
...  
Keyword(s):  
Physical Adsorption ◽  
Experimental System ◽  
Confining Pressure ◽  
Gas Pressure ◽  
Seepage Velocity ◽  
Adsorption Method ◽  
Pressure System ◽  
Gas Seepage ◽  
Confining Pressures ◽  
Seepage Properties

Pore structure of soft-slicing coal (SSC) is analyzed with physical adsorption method. Several experiment schemes are designed to carry out the tests of gas seepage characteristics of soft-slicing coal at the different confining pressures, gas pressures and axial pressures, with the self-developed gas seepage triaxial pressure experimental system. The typical coal from TianFu coal mine is especially sampled with different designed surface area parameters. The experiment results demonstrate the relations between the seepage velocity, the effective axial feed, and gas pressure. Under the conditions of the constant axial and confining pressure, the seepage velocity increases in an exponent way with gas pressure increasing, the permeability coefficient decreases in negative exponent, and this seepage process shows capacity fractal properties.

Study on Gas Flow Law in Goaf of Huangling No.1 Mine Fully-Mechanized Face

2014 ◽  
Vol 1010-1012 ◽  
pp. 1548-1553
Author(s):  
Tian Xuan Hao ◽  
Meng Liu
Keyword(s):  
Numerical Simulation ◽  
Gas Flow ◽  
Sampling Method ◽  
Concentration Field ◽  
High Fracture ◽  
Gas Concentration ◽  
Working Face ◽  
Fluent Software ◽  
Gas Control ◽  
Important Basis

The gas concentration field in goaf of Huangling No.1 Mine 304 fully-mechanized face was simulated numerically by FLUENT software with high fracture drilling or not. The results of numerical simulation were confirmed by fixed sampling method of immersed tube in goaf. Thus, the law of gas concentration field was gained, which provides the important basis for gas control of working face.

Numerical Simulation Study on Combined Supporting Scheme of Bolts and Anchor Cable

2014 ◽  
Vol 638-640 ◽  
pp. 898-903
Author(s):  
Wen Cai Wang ◽  
Wen Bin Wei ◽  
Ling Wang
Keyword(s):  
Numerical Simulation ◽  
Simulation Study ◽  
Coal Mine ◽  
Simulation Software ◽  
Practical Application ◽  
Anchor Cable ◽  
Result Show ◽  
The Face

Aiming at the face roadway 22109 of Cuncaota coal mine, using FLAC3Dnumerical simulation software, 19 of 5 groups about bolt and anchor combined support schemes were analysed and compared, and the reasonable scheme of φ18×2000mm thread steel bolt and φ17.8×6500mm anchor cable combined support was obtained. Support result of this scheme was analysed with FLAC3Dsoftware, the result show that this scheme can support the roadway effectively. Practical application show that this scheme can achieve the security, economical and effective support result, and can be used in this type of roadway.

Study on Theoretical Analysis and Numerical Simulation of Smoke Flow during Gas Explosion

2010 ◽  
Vol 29-32 ◽  
pp. 125-131
Author(s):  
Zhi Ming Qu
Keyword(s):  
Numerical Simulation ◽  
High Temperature ◽  
Coal Dust ◽  
Treatment Plan ◽  
Ventilation System ◽  
Gas Explosion ◽  
Gas Concentration ◽  
Working Face ◽  
Hazardous Area ◽  
Secondary Disasters

In most cases, high gas concentration and oxygen consumption result in severe hypoxia after explosion. When the ventilation system is damaged, the air volume will be re-distributed so that explosion region is lack of oxygen. However, under mechanical ventilation and self-diffusion, the high temperature and toxic and harmful gases will constantly spread downwind of the roadway or certain areas, which threatens substations, winch room and workers’ escape. If the hot gas meets with gas concentration overrun areas or the coal dust explosion hazardous area, secondary disasters such as fire or explosion may be caused. Numerical simulation shows that high temperature, toxic and harmful gas will be disseminated. In conclusion, measures must be taken to withdraw the workers and to restore ventilation to prevent secondary disasters. If the gas explosion power is increased, the safety nearby working face would be threatened. To control and reduce the extent of gas explosion hazards and losses, a reasonable gas explosion disaster prevention and treatment plan should be established.

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