The Impact of Cutting with a Shearer on the Conditions of Longwall Ventilation

Dziurzyński, W.; Krach, Andrzej; Pałka, T.; Wasilewski, S.

doi:10.3390/en14216907

Cited by 4 publications

(5 citation statements)

References 9 publications

(8 reference statements)

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“…The determination of the transient methane concentration changes experienced over time at the terrain surface of the "A" mine being closed, and the value of this methane concentration, was the primary objective of the research. in order to achieve the aim of the research, the numerical simulation method was assumed [20] with use of the VentGraph-Plus computer software package [21][22][23][24][25].…”

Section: The Object and Methodology Of The Researchmentioning

confidence: 99%

“…To simulate flow phenomena with VentGraph-Plus software, one should prepare a dataset containing the set of ventilation parameters, identifying the structure of mine excavations together with goafs, with consideration given to methane inflow. The mathematical model used in the VentGraph-Plus software was the subject of many publications [24][25][26]. Preparation of database for numerical model determination (fig.…”

Section: Closure Of the "A" Mine Mine Excavations Ventilation Shut Do...mentioning

confidence: 99%

“…The results of computations will be presented on graphs of methane concentration changes in time, recorded by virtual sensors of VentGraph-Plus program [25]. for the assumed initial conditions, in every time step computation of the air and methane flow distribution takes place and methane concentration distribution in the mine excavations is also computed (10 sec.…”

Section: The Simulation Of the Air And Methane Flow Distribution Duri...mentioning

confidence: 99%

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Methane Hazard during the Closure of Mine Excavations in Liquidated Mine – Numerical Simulation

2023

Archives of Mining Sciences

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Methane hazard during the closure of Mine excavations in liquidated Mine -nuMerical siMulationThe closure of deep mines, featuring multi level seam extraction, lasts many years. During this time period, the ventilation system must ensure adequate working conditions, and ensure the safety and stability of fan operation in gas and fire hazards conditions. The analysis of air flows and methane inflows during the progress of mining mine excavations closure, is the primary object of the article. Execution of such analysis requires knowledge of the mining mine excavations' closure schedule, the structure of the ventilation system under consideration, the values of the parameters describing the air flows delivered to the mine excavations, and the current characteristics of operating fans and predicted methane exhalation. A computer database, currently being updated by a mine ventilation department for the VentGraph-Plus computer software, has been used simulate the various ventilation scenarios experienced, during the final stage of closure, including the shutdown of the main fans and the backfilling of shafts. The results of case study, containing 2 variants of simulated examples, are presented in the form of diagrams of methane concentration changes in time at characteristic places of the mine. The completed simulations of ventilation processes during the closure of mine excavations and transfer of inflowing methane, indicate useful possibilities of the computational tool used.

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Section: The Object and Methodology Of The Researchmentioning

confidence: 99%

Section: Closure Of the "A" Mine Mine Excavations Ventilation Shut Do...mentioning

confidence: 99%

Section: The Simulation Of the Air And Methane Flow Distribution Duri...mentioning

confidence: 99%

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Methane Hazard during the Closure of Mine Excavations in Liquidated Mine – Numerical Simulation

2023

Archives of Mining Sciences

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“…At present, complex coal seam geological conditions have a series of engineering problems for mainstream mining technology [4][5][6][7], which are characterized by high hardness or high brittleness. These conditions lead to high energy consumption and severe wear and tear of the picks in conventional mechanical cutting technology.…”

Section: Introductionmentioning

confidence: 99%

A Data Mining Method for Constitutive Model of Hard Brittle Coal

Qiang Zhang

2024

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Data mining is an effective way to solve various types of complex nonlinear problems. And the anisotropy of the mechanical characteristics of coal is a typical nonlinear problem. Hard coal seam are usually characterized by brittleness, which makes them difficult to be crushed efficiently. It is important to improve the efficiency of hard coal crushing by the brittleness characterization method of hard coal is clarified. So the constitutive model and damage mechanism of hard brittle coal was studied in this paper. Damage model of hard brittle coal based on Weibull distribution was established. The damage transition point concept was proposed based on the deformation stage characteristics of hard brittle coal. And effective damage intervals for hard brittle coals can be determined based on the damage transition point. Uniaxial compression experiments of hard brittle coal were simulated using EDEM. The characterization of the effect of discrete elemental eigenstructural parameters on the brittleness of coal was analyzed. And quantitative relationships between shear modulus and brittleness, brittleness and damage transition point were fitted by Matlab. A discrete elemental constitutive model for hard brittle coals was obtained. Finally, the correctness of discrete elemental constitutive model was verified by comparing uniaxial compression experiments with other specimens. The results of this paper were expected to provide a theoretical basis for the crushing technology of hard brittle coal. And the numerical theoretical basis for data mining of the intrinsic model of hard and brittle coal was provided.

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“…In the past, mine ventilation systems have been successfully modeled using network based flow simulation programs such as MineVent, VentZroby and VnetPC (Karacan, 2009a). Work done using network type simulation by researchers in Poland (Dziurzynski & Wasilewski, 2012).…”

Section: Previous Numerical Simulation Studiesmentioning

confidence: 99%

Multiple simulation experimental studies of gas emission, distribution and migration rules in mine ventilation system and goaf area

Zhang

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Gas problems have created severe difficulties for the mining industry around the world, leading to high expenditures and intensity research efforts, and determined attempts to enhance the various ventilation optimization and gas drainage techniques. Meanwhile, gas research is thriving in recent years, and gas drainage technology will continue to be a growing industry over the coming decades in many mining countries. Safety mining technologies including field investigation, numerical simulation and laboratorial experiments have been improved to develop a better understanding of the causes of mine gas-related disasters over the last two decades. In addition, new and multiple gas control strategies and technologies have been developed, including optimizing the ventilation system constantly, preventing goaf spontaneous combustion timely, enhancing gas risk management effectively, determining the gas emission zone exactly, and implementing a reasonable gas drainage plan correctly. The first part of the dissertation introduces a multiple gas disaster prevention, control and reduction strategy. Firstly, the basic theories of gas emission, distribution and migration are discussed. Then a numerical prediction model based on a specific coal mine is established to predict its gas emission. The second part of the dissertation offers the establishment of the numerical simulation model (CFD) and laboratorial experimental model for the purpose of discussing the gas distribution and migration rule and determining the most effective gas drainage zones in the working face and goaf. Both of the numerical simulation results and the laboratorial experimental results also demonstrate that the most effective gas drainage spot constantly varies with the area where mining activities are performed. In the case of numerical simulation experimental results, it is mainly located in the area of 40m-250m (between working face and deep goaf), 30m-40m from the working face floor (between the working face floor to the roof), and approximately 60m-170m (between air inlet and air outlet). In the case of laboratorial simulation experimental results, it mainly locates in coal seam and rock stratum separation area of 27cm-243cm (between working face and deep goaf), 28cm-42cm (between the working face floor to the roof) and 78cm-182cm (between air inlet and air outlet). The last part of this dissertation provides a field study in order to obtain the gas distribution and migration rule in the working face and goaf. The field measured results show the average gas drainage rate increased from 39.6 m3·min-1 (U-type ventilation system) to approximately 48.9 m3·min-1 (U+L-type ventilation system) while the gas concentration of the special drainage tunnel, upper corner and air outlet decreased from 1.88%, 0.85% and 0.61% (U-type ventilation system) to 1.69%, 0.75% and 0.55% (U+L-type ventilation system), respectively. These results indicate the layout of the gas drainage boreholes is rational and effective; the gas drainage volume is reliable. Therefore, it is feasible and reliable to arrange the layout of gas drainage tunnels based on the experimental results of numerical simulation and laboratorial test. Los problemas ocasionados por gas han creado graves dificultades para la industria minera en todo el mundo, por lo que ha implicado altos gastos y esfuerzos de investigación y intentos de mejorar en diversas técnicas de optimización de la ventilación y drenaje de gas. Mientras tanto, la investigación sobre gas ha aumentado considerable en los últimos años y la tecnología de drenaje de gas seguirá siendo una industria en crecimiento en las próximas décadas en muchos países mineros. Las tecnologías mineras de seguridad, incluyendo la investigación de campo, la simulación numérica y experimentos en laboratorio han mejorado para una mejor comprensión de las causas de los desastres relacionados con el gas de las minas en las últimas dos décadas. Además, se han desarrollado nuevos y múltiples estrategias y tecnologías de control de gas, incluyendo la optimización del sistema de ventilación, impidiendo excavaciones de combustión espontánea oportuna, mejorando así la gestión eficaz de riesgos causados por gases, determinando la zona de emisión de gases con exactitud, y la implementación de un plan de drenaje de gas correctamente. La primera parte de la tesis se presenta una estrategia múltiple de la prevención de desastres de gas, control y reducción. En primer lugar, se analizarán las teorías básicas de la emisión de gases, la distribución y la migración. Luego se establecerá un modelo de predicción numérica basada en una mina de carbón específica para predecir su emisión de gases. La segunda parte de la tesis ofrece el establecimiento del modelo numérico de simulación (CFD) y el modelo experimental de laboratorio con el fin de discutir la distribución de gas y norma de migración y la determinación de las zonas de drenaje de gas más eficaces en el frente de trabajo y terraplén. Tanto los resultados del simulación numéricos como los resultados experimentales de laboratorio demuestran que el punto de drenaje más eficaz de gas varía constantemente según el área donde se realizan las actividades mineras. En el caso de los resultados experimentales de simulación numérica, que se encuentra principalmente en el área de 40m-250m (entre la superficie del tierra y el zona excavada), 30m-40m desde la superficie de trabajo (desde la superficie del trabajo hasta el techo), y aproximadamente 60m-170m (entre el entrada y salida de aire). En el caso de los resultados experimentales de simulación en el laboratorio, se localiza principalmente en la veta de carbón y la zona de separación del estrato rocoso de 27cm-243cm (entre la superficie de la tierra y la zona excavada), 28cm-42cm (desde la superficie del trabajo hasta el techo) y 78cm-182cm (entre la entrada y salida de aire). La última parte de esta tesis concluye un estudio de campo con el fin de obtener la distribución de gas y el estado migratorio entre la superficie y la zona escavada. Los resultados de campo medidos muestran que la tasa de drenaje de gas en promedio aumentó 39,6 m3·min-1 (sistema de ventilación de tipo T) a aproximadamente 48,9 m3 · min-1 (sistema de ventilación de T + L-tipo), mientras que la concentración de gas del drenaje especial en túnel, esquina superior y salida de aire se redujo de 1,88%, 0,85% y 0,61% (sistema de ventilación de tipo U) a 1,69%, 0,75% y 0,55% (U + de tipo L sistema de ventilación), respectivamente. Estos resultados indican que la disposición de las perforaciones de drenaje de gas es racional y eficaz; el volumen de drenaje de gas es fiable. Por lo tanto, es factible y fiable para organizar la disposición de túneles de drenaje de gas sobre la base de los resultados experimentales de simulación numérica y la prueba de laboratorio.

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The Impact of Cutting with a Shearer on the Conditions of Longwall Ventilation

Cited by 4 publications

References 9 publications

Methane Hazard during the Closure of Mine Excavations in Liquidated Mine – Numerical Simulation

Methane Hazard during the Closure of Mine Excavations in Liquidated Mine – Numerical Simulation

A Data Mining Method for Constitutive Model of Hard Brittle Coal

Multiple simulation experimental studies of gas emission, distribution and migration rules in mine ventilation system and goaf area

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