scholarly journals Fluid–Solid Coupling Model and Simulation of Gas-Bearing Coal for Energy Security and Sustainability

Processes ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 254
Author(s):  
Shixiong Hu ◽  
Xiao Liu ◽  
Xianzhong Li
Keyword(s):  
Numerical Simulation ◽  
Coal Mining ◽  
Energy Security ◽  
Gas Flow ◽  
Coupling Model ◽  
Simulation Software ◽  
Klinkenberg Effect ◽  
Gas Drainage ◽  
Model And Simulation ◽  
Gas Bearing

The optimum design of gas drainage boreholes is crucial for energy security and sustainability in coal mining. Therefore, the construction of fluid–solid coupling models and numerical simulation analyses are key problems for gas drainage boreholes. This work is based on the basic theory of fluid–solid coupling, the correlation definition between coal porosity and permeability, and previous studies on the influence of adsorption expansion, change in pore free gas pressure, and the Klinkenberg effect on gas flow in coal. A mathematical model of the dynamic evolution of coal permeability and porosity is derived. A fluid–solid coupling model of gas-bearing coal and the related partial differential equation for gas migration in coal are established. Combined with an example of the measurement of the drilling radius of the bedding layer in a coal mine, a coupled numerical solution under negative pressure extraction conditions is derived by using COMSOL Multiphysics simulation software. Numerical simulation results show that the solution can effectively guide gas extraction and discharge during mining. This study provides theoretical and methodological guidance for energy security and coal mining sustainability.

scholarly journals Influence of Long Boreholes Layout and Drilling Length on Gas Drainage Based on Multifield Coupling Model of Gas-Bearing Coal

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Renjun Feng
Keyword(s):  
Coupling Model ◽  
Specific Reference ◽  
Gas Migration ◽  
Quantitative Characterization ◽  
Gas Drainage ◽  
Drainage Time ◽  
Working Face ◽  
Drainage Effect ◽  
Gas Bearing

Gas drainage through long seam boreholes is an effective method to prevent gas disasters in coal mines. In this paper, a multifield coupling model of gas migration in gas-bearing coal was first established. Then, a quantitative characterization method of gas drainage effect was put forward. Finally, the extraction effect of long boreholes was obtained under different layouts and drilling lengths. The research results show that, under the arrangement of long boreholes along the seam, the gas pressure around the borehole decreases significantly with the extraction time. There is no extraction blank in the middle of the working face. However, it is easy to cause uneven gas drainage in the combined arrangement of the long boreholes along the seam and the penetrating boreholes. Furthermore, it is found that the drainage volume of the long boreholes along the seam is similar to that of the joint layout under the same drainage time. As the length of the borehole increases, the influencing range of gas drainage increases. When the borehole lengths are 150 m and 240 m, the drainage volumes are about 1.31 and 2.50 times that of the 90 m boreholes, respectively. The research achievements could provide a specific reference for the layout of long boreholes along the bedding and the determination of reasonable parameters for gas drainage on site.

The Study on Roadway Layout in Coordination of Mining Coal Seams Base on Failure of Floor Strata

2014 ◽  
Vol 889-890 ◽  
pp. 1362-1374 ◽  
Author(s):  
Yong Zhang ◽  
Chun Lei Zhang ◽  
Chun Chen Wei ◽  
Ya Dong Liu ◽  
Shi Qing Zhang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Theoretical Analysis ◽  
Coal Seam ◽  
Coal Mining ◽  
Coal Mine ◽  
Simulation Software ◽  
Coal Seams ◽  
Group Coordination ◽  
Mining Coal ◽  
Two Sides

In order to make sure the reasonable roadway layout in lower seam of close coal mining group coordination in Lijiahao coal mine, firstly, applying the theoretical analysis and geological radar detection to get the influence depth of mining from the up coal seam 2-2 to the floor is about 20m, the results show that the thickness of complete strata is about 15m, then determining to use the outward alternate entries in lower seam roadway by using theoretical analysis. At last, determining the distance of outward alternate entries is 12-14m by using FLAC3D numerical simulation software to simulate the change of stress and displacement in roof floor and two sides of roadway.

scholarly journals Research on the Effective Influence Radius of Hydraulic Reaming in Mining Seam

2015 ◽  
Vol 8 (1) ◽  
pp. 161-167
Author(s):  
Li Peng ◽  
Wang Kai ◽  
Li Bo ◽  
Jiang Yifeng ◽  
Gou Jianqiang
Keyword(s):  
Gas Flow ◽  
Coupling Model ◽  
Field Investigation ◽  
Coal Mass ◽  
Gas Content ◽  
Coal Seams ◽  
Gas Drainage ◽  
Permeability Increase ◽  
Influence Radius ◽  
Drainage Effect

In Accordance with the present situations suggesting that the construction of the gas drainage boreholes in mining seam is sufficient and the gas drainage effect in low permeability coal seams does not yield perfectly, the hydraulic reaming technology in mining seam was proposed to increase the gas drainage efficiency. Through the gas flow method, the effective influence radius of hydraulic reaming was determined and the fluid-solid coupling model of gas drainage along boreholes after hydraulic reaming was established theoretically. Following this, the changes in the laws of gas content around the boreholes in the coal seam were simulated and analyzed. The results indicated that hydraulic reaming can effectively promote the stress-relief and permeability-increase of the coal mass around the boreholes, and the coal mass around the reaming boreholes can be divided into gas flow increase zone, gas flow delay attenuation zone and fast decay zone. The effective influence radius of hydraulic reaming was 5.5~6 m. The obtained simulation results were basically in accordance with the field investigation.

Solid-Gas Coupling Model and Numerical Simulation of Coal Containing Gas Based on Comsol Multiphysic

2012 ◽  
Vol 616-618 ◽  
pp. 515-520
Author(s):  
Sheng Zhou Li ◽  
Chang Bao Jiang ◽  
Jun Wei Yao ◽  
Ming Hui Li
Keyword(s):  
Numerical Simulation ◽  
Failure Modes ◽  
Coupling Effect ◽  
Coupling Model ◽  
Klinkenberg Effect ◽  
Deformation And Failure ◽  
Finite Element Software ◽  
Porosity And Permeability ◽  
Simulation Results ◽  
Seepage Law

Solid-gas coupling effect of coal containing gas is studied in order to understand the gas percolation mechanism in coal and rock. On the premise of that porosity and permeability of coal and rock are in dynamic changes and Klinkenberg effect, then seepage mechanics and elastic-plastic mechanics are considered together to established solid-gas coupling model of coal containing gas. With the given fixed solution conditions and parameters, the simulation results of mathematical model is found by the Comsol Multiphysic finite element software. Simulation results are consistent with the stress-strain law, deformation and failure modes of specimen in the experiment. Seepage law obtained in numerical simulation has same trends with experimental data. The elastoplastic solid-gas coupling model of coal containing gas can effectively describe the mechanical percolation characteristics of coal containing gas.

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.

Analysis of Numerical Simulation on Breaking Law of the Composite Key Stratum Affected by Coal Mining

2012 ◽  
Vol 616-618 ◽  
pp. 350-355
Author(s):  
Hai Feng Ren ◽  
Shu Gang Li ◽  
Hong Yu Pan
Keyword(s):  
Numerical Simulation ◽  
Coal Mining ◽  
Simulation Software ◽  
Composite Effect ◽  
Key Stratum ◽  
The Law

Using FLCA3Dnumerical simulation software, analyzed the different models of different extraction from the composite key layer of breaking the law, respectively to the Composite Key Stratum and non-Composite Key Stratum .The results show that Composite Key Stratum breaking interval was significantly greater than The non-Composite Key Stratum, showing a more obvious composite effect, provides a more adequate proof to the Composite Key Stratum theory.

Numerical Simulation on the Influence of Mining-Induced Fractures Field on Gas Drainage and its Application

2011 ◽  
Vol 90-93 ◽  
pp. 477-484
Author(s):  
Shu Jing Zhang ◽  
Yong Wei Peng ◽  
Yong Jiang Yu
Keyword(s):  
Numerical Simulation ◽  
Coal Seam ◽  
Gas Flow ◽  
Underground Mining ◽  
High Strength ◽  
Gas Pressure ◽  
Comsol Multiphysics ◽  
Coal Seam Gas ◽  
Gas Drainage ◽  
Induced Fractures

In order to study the influence of mining-induced fractures field on gas drainage,the paper adopts software of numerical simulation COMSOL Multiphysics to simulate gas drainage of coal seam under the condition of high-strength underground mining. The main aspects can be seen as the following: (1) In the case without considering the fractures, gas drainage in single hole, the gas pressure distribution showed a funnel-type distribution in space along the drainage holes around. (2) The orientation and direction of fractures play a major role on the flow field of gas. In the region that exits fractures, the distribution of gas pressure has a clear fluctuation and adjustment.(3) The numerical simulation of coal seam gas drainage that considered the fracture of coal mining, was closer to the true gas flow.

Numerical Simulation of Flow Field in Cylinder of Gasoline Engine

2012 ◽  
Vol 220-223 ◽  
pp. 826-829
Author(s):  
Yun Jing Jiao ◽  
Man Qun Lin ◽  
Xuan Wang ◽  
Xue Yan Wang ◽  
Xi Cheng Yan
Keyword(s):  
Numerical Simulation ◽  
High Speed ◽  
Gas Flow ◽  
Gasoline Engine ◽  
Transient State ◽  
Simulation Software ◽  
Maximum Torque ◽  
Compression Stroke ◽  
Crank Angle ◽  
The Stability

Abstract: By adopting CFD numerical simulation software, the transient state numerical simulation of engine is carried on. The intake and compression stroke are studied in maximum power and maximum torque conditions. Through numerical simulation, we can learn the change of TKE with the crank angle, and give a guide for improving design of intake port and chamber. At last, a conclusion is found about the engine that at high speed, the gas flow in cylinder infects the stability of spark ignition.

Study on Reasonable Filling Width of Gob-Side Entry Retaining and its Engineering Application

2013 ◽  
Vol 807-809 ◽  
pp. 2288-2293 ◽  
Author(s):  
Xiang Qian Wang ◽  
Xiang Rui Meng ◽  
Zhao Ning Gao
Keyword(s):  
Numerical Simulation ◽  
Coal Mining ◽  
Coal Mine ◽  
Field Measurement ◽  
Engineering Application ◽  
Coal Pillar ◽  
Simulation Software ◽  
Mining Face ◽  
Pillar Size

Based upon the engineering background of IV315 coal mining face of Mengzhuang Coal Mine, the numerical simulation software UDEC is used to analyze rational packing width under the conditions of different filling widths on the driving roadway. The rational coal pillar size is initially decided as 2.0 meters through simulating and analyzing. On this basis, the influence of second mining on the retaining roadway was analyzed by numerical simulation. Combined with the field measurement, the support parameters and the 2.0 meters packing width are proven to be rational, which provides a reference for the coal mining faces with similar conditions.

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