Coupling Model of Evolution of Mining Fissure Elliptic Paraboloid Zone and Methane Delivery

2013 ◽  
Vol 734-737 ◽  
pp. 546-550 ◽  
Author(s):  
Hai Fei Lin ◽  
Rui Feng Ma ◽  
Shu Gang Li ◽  
Lian Hua Cheng ◽  
Hong Yu Pan ◽  
...  
Keyword(s):  
Initial Conditions ◽  
Drainage System ◽  
Seepage Flow ◽  
Coupling Model ◽  
Gas Diffusion ◽  
Elliptic Paraboloid ◽  
Field Coupling ◽  
Deformation Equation ◽  
Gas Seepage ◽  
Mass Transfer Theory

After mining, a dynamic distribution of mining fissure elliptic paraboloid zone in the overlying stratum would be formed. Based on the rock mechanics, seepage flow mechanics, mass transfer theory and elastic-plastic theory, the coal-rock mass deformation equation, mixture gas seepage equation and gas diffusion equation of the mining fissure elliptic paraboloid zone are deduced. Combined with various boundaries, initial conditions, the multi-field coupling mathematical model of mining fissure elliptic paraboloid is obtained. The model provides a theoretical basis for numerical simulation of gas drainage system layout.

scholarly journals The dynamic evolution analysis of gas seepage field during the mining process of protective layer

2019 ◽  
Vol 23 (3 Part A) ◽  
pp. 1371-1378
Author(s):  
Hongmei Cheng ◽  
Yuxia Dong ◽  
Xiru Li ◽  
Heng Chen
Keyword(s):  
Protective Layer ◽  
Gas Diffusion ◽  
Dynamic Evolution ◽  
Gas Extraction ◽  
Seepage Field ◽  
Field Coupling ◽  
Evolution Analysis ◽  
Gas Seepage ◽  
Fortran Language ◽  
Analytical Program

The process of gas extraction by the protective layer mining is actually the multi-field coupling process. In this paper, the governing equations of the gas diffusion and seepage in the damaged coal and rock mass under the condition of the coupling action of gas and solid are established. A multi-field coupling analytical program is compiled by the FORTRAN language. The distribution and dynamic evolution law of the gas seepage field of the protected layer are calculated and analyzed. The result will provide the data support for the gas extraction design.

scholarly journals A Study on the Mechanical Mechanism of Injection Heat to Increase Production of Gas in Low-Permeability Coal Seam

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2332 ◽  
Author(s):  
Hongmei Cheng ◽  
Ning Zhang ◽  
Yugui Yang ◽  
Weihong Peng ◽  
Heng Chen
Keyword(s):  
Rock Mass ◽  
Coal Seam ◽  
Production Efficiency ◽  
Gas Diffusion ◽  
Gas Production ◽  
Gas Pressure ◽  
Coal Bed ◽  
Coal Bed Methane ◽  
Field Coupling ◽  
Gas Seepage

This paper puts forward a new mathematical model, which is a coal damage-heat-fluid-solid multi-field coupling theory, in order to reveal the mechanical mechanism of the increase of coal-bed methane recovery through thermal stimulation, and to evaluate its effect. The strain field is introduced to define the damage of coal by considering of the effects of temperature, gas pressure, and mining stress of the coal seam. It is used to quantitatively describe the degree of coal rupture and damage. Additionally, the elastic and damage constitutive equation of coal and rock mass, the governing equation of the temperature field, and the coupling equation of gas diffusion and seepage are established. Based on these equations, the finite element source program is redeveloped by using the FORTRAN language, and a multi-field coupling analysis program is compiled. This program takes the temperature, the gas seepage, and the damage and deformation of coal and rock mass into consideration. The effect of heat injection temperature on gas production efficiency, gas pressure distribution, and effective extraction radius during coal-bed methane mining process is analyzed. The results show that the injection of heat can significantly improve the desorption and diffusion of gas, as well as the gas production rate and the production efficiency of coal-bed methane.

Predicting the number of fiber roots in lola drafting based on multi-field coupling

2020 ◽  
Vol 90 (23-24) ◽  
pp. 2769-2781
Author(s):  
Xin rong Li ◽  
LiuBo Wu ◽  
Zhaoning Bu ◽  
Lidong Liu
Keyword(s):  
Change Point ◽  
Production Efficiency ◽  
Slip Rate ◽  
Sharp Decrease ◽  
Coupling Model ◽  
Production Costs ◽  
Weak Effect ◽  
Field Coupling ◽  
Theoretical Support ◽  
New Type

Pullout theory is very important in improving efficiency, quality, and production costs. Because production efficiency is too low for mechanical drafting equipment, a simple multi-field coupling model of fiber mechanics based on conserving momentum is proposed that considers the distribution of the fiber speed point, slip rate, and friction mechanics. When the roller draft multiple is increased, the position near the rear roller clamp mouth in the draft area will show a sharp decrease of fiber, which is caused by the rapid movement of the front fiber to drive the floating fiber movement, and it is also the existence of the fiber change point. When the roller spacing increases, the draft efficiency decreases, although the pressure applied by the roller to the fibrous strip has a weak effect on the draft efficiency. This research increases our understanding of drawing and provides theoretical support for the design of a new type of drawing.

scholarly journals Design of the Artificial Bone Scaffolds Based on the Multi-field Coupling Model

Procedia CIRP ◽  
2016 ◽  
Vol 56 ◽  
pp. 95-99 ◽  
Author(s):  
Xue Xing ◽  
Yao Chen ◽  
Xiu-Tian Yan ◽  
Guo-yuan Zhang
Keyword(s):  
Coupling Model ◽  
Artificial Bone ◽  
Field Coupling ◽  
Bone Scaffolds

Lightweight Research of Automobile Dash Panel Based on Sound-Structure Sensitivity

2013 ◽  
Vol 681 ◽  
pp. 200-203 ◽  
Author(s):  
Lei Zhang ◽  
Zhi Yong Hao
Keyword(s):  
Sound Pressure ◽  
Lightweight Design ◽  
Sound Field ◽  
Coupling Model ◽  
Structure Sensitivity ◽  
Car Body ◽  
Field Coupling ◽  
Sound Structure ◽  
Dash Panel

In the research of the automobile front dash, the key of design is that acoustic need should be satisfied while losing the weight. In this paper, a structure-sound field coupling model of car body space is built. To fulfill the request, the dash panel is divided into several parts, and the sensitivity of thickness of each parts to the sound at the position of driver’s and co-pilot’s ears is calculated. Based on the sensitivity, the driver’s and the co-pilot’s parotic sound pressure is optimized while reducing the weight of front dash. The result proves that lightweight design is successful, which gives the reference to the design of the car body panels.

scholarly journals Establishment and application of heat flow coupling model

2019 ◽  
Vol 23 (1) ◽  
pp. 207-218
Author(s):  
Jun He ◽  
Gao-Liang Peng ◽  
Ling-Tao Yu ◽  
Chen-Zheng Li ◽  
Chuan-Hao Li ◽  
...  
Keyword(s):  
Heat Flow ◽  
Real Time ◽  
Initial Conditions ◽  
Coupling Model ◽  
Productive Efficiency ◽  
Maximum Deviation ◽  
Inspection Method ◽  
The Real ◽  
Flow Coupling ◽  
Washing Process

Wax deposition on walls of oil pipes is a common occurrence in crude oil extraction and is one of the major impediments to oilfield production. The most common method of paraffin removal is superconducting car thermal washing. This study proposes a heat flow coupling model that can analyze the temperature of the tubing-casing annular space to solve the low efficiency problem caused by adjusting initial parameters empirically. Using the superconducting car thermal washing process at the test oil well in city of Daqing, Chine as research object, the real-time temperature of annulus under various initial conditions is acquired by the fully-distributed Raman optical fiber temperature monitoring system. Compared with the real time data, theoretical data has a maximum deviation of 5?C, this result verifies the accuracy of the model. Based on the model, the study investigates the optimal initial parameters of superconducting car thermal washing by taking effective depth as an optimization goal. The optimal parameters for oil wells with different working conditions are obtained to improve the effectiveness of paraffin removal and increase thermal efficiency. This study provides theoretical support and an inspection method to promote superconducting car thermal washing and paraffin removal as well as to improve productive efficiency.

scholarly journals Thermos-Solid-Gas Coupling Dynamic Model and Numerical Simulation of Coal Containing Gas

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Xiao Fukun ◽  
Meng Xin ◽  
Li Lianchong ◽  
Liu Jianfeng ◽  
Liu Gang ◽  
...  
Keyword(s):  
Principal Stress ◽  
Dynamic Model ◽  
Gas Flow ◽  
Flow Behavior ◽  
Coupling Model ◽  
Gas Pressure ◽  
Permeability Model ◽  
Gas Seepage ◽  
Coupling Dynamic ◽  
Coupling Dynamic Model

Based on gas seepage characteristics and the basic thermo-solid-gas coupling theory, the porosity model and the dynamic permeability model of coal body containing gas were derived. Based on the relationship between gas pressure, principal stress and temperature, and gas seepage, the thermo-solid-gas coupling dynamic model was established. Initial values and boundary conditions for the model were determined. Numerical simulations using this model were done to predict the gas flow behavior of a gassy coal sample. By using the thermo-solid-gas coupling model, the gas pressure, temperature, and principal stress influence, the change law of the pressure field, displacement field, stress field, temperature field, and permeability were numerically simulated. Research results show the following: (1) Gas pressure and displacement from the top to the end of the model gradually reduce, and stress from the top to the end gradually increases. The average permeability of the Y Z section of the model tends to decrease with the rise of the gas pressure, and the decrease amplitude slows down from the top of the model to the bottom. (2) When the principal stress and temperature are constant, the permeability decreases first and then flattens with the gas pressure. The permeability increases with the decrease of temperature while the gas pressure and principal stress remain unchanged.

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