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Articles 1 - 14 of 14
Full-Text Articles in Physical Sciences and Mathematics
Structure Optimization Of Foam Generator For Soft Coal Seam And Foaming Effect Simulation, Jin Xin
Structure Optimization Of Foam Generator For Soft Coal Seam And Foaming Effect Simulation, Jin Xin
Coal Geology & Exploration
Objective The application of air screw drilling technology in gas drainage borehole within soft coal seam presents challenges, including severe dust pollution, low drill bit lifespan, and great difficulty in borehole purification. The use of air screw foam drilling technology is an effective way to solve the problem. A foam generator with good foaming performance is one of the keys to implementing the foam drilling technology. However, most current foam generators could not meet the requirements. Methods In response to this issue, a small-sized foam generator was designed based on the spiral foam generator, with an air kinetic energy conversion …
Characteristics Of Gas Bursting And Application Of Layered Cutting Drilling In Outburst Coal Seam, Wang Yonglong, Zhao Aoqi, Yu Zaijiang, Wang Zhenfeng, Liu Xiao, Ma Denghui, Zhang Hui, Liu Chun
Characteristics Of Gas Bursting And Application Of Layered Cutting Drilling In Outburst Coal Seam, Wang Yonglong, Zhao Aoqi, Yu Zaijiang, Wang Zhenfeng, Liu Xiao, Ma Denghui, Zhang Hui, Liu Chun
Coal Geology & Exploration
Objective The overlimit gas bursting in the drilling process of outburst coal seam is a safety hazard that threatens the efficient production of the mine. The layered cutting drilling method helps to weaken the burst gas pressure in the borehole, but the characteristics of gas release around the trapezoidal borehole formed by layered cutting are unknown, which limits the structural design and application effect of the layered cutting drilling tool. Methods Herein, study was conducted based on the layered cutting boreholes with different layer spacing and layer thickness difference. Specifically, a mathematical model was established to analyze the gas flow …
Periodic Roof Deformation And Failure And Associated Water Inflow Characteristics During The Mining Of Typical Coal Seams In The Inner Mongolia-Shaanxi Contiguous Area, Zhou Zhenfang, Dong Shuning, Dong Yang, Luo Shenghu, Xue Jiankun, Wang Zhizhou, Wang Shuxuan, Shang Hongbo, Wang Tiantian, Wang Yutong, Wang Tong
Periodic Roof Deformation And Failure And Associated Water Inflow Characteristics During The Mining Of Typical Coal Seams In The Inner Mongolia-Shaanxi Contiguous Area, Zhou Zhenfang, Dong Shuning, Dong Yang, Luo Shenghu, Xue Jiankun, Wang Zhizhou, Wang Shuxuan, Shang Hongbo, Wang Tiantian, Wang Yutong, Wang Tong
Coal Geology & Exploration
[Objective] The disturbance of coal mine mining damages the aquifer/aquiclude structures of the overburden, causing concentrated water inflow and further affecting safe production in mines. [Methods] Using methods of the physical simulation of similar materials, numerical simulation, and on-site in situ monitoring, this study investigated the water inflow during the mining of the dominant 3-1 coal seam, typically influenced by water in sandstones on the coal seam roof, in the Inner Mongolia-Shaanxi contiguous area. By comparing the measured data of mines with similar geological and mining conditions in the surrounding area, this study delved into the periodic evolutionary patterns of …
Mechanical Characteristics And Fracture Propagation Mechanism Of Deep Coal Reservoirs In The Shenfu Block, Mi Honggang, Wu Jian, Peng Wenchun, Xu Lifu, Li Yong
Mechanical Characteristics And Fracture Propagation Mechanism Of Deep Coal Reservoirs In The Shenfu Block, Mi Honggang, Wu Jian, Peng Wenchun, Xu Lifu, Li Yong
Coal Geology & Exploration
[Objective] Clarifying the mechanical properties and in-situ stress distributions of coal seams, along with the mechanisms behind their control over the morphologies and propagation behavior of artificially induced fractures, is crucial to the fracturing design, well pattern deployment, and coalbed methane (CBM) production of deep coal seams. [Methods] This study investigated the Nos. 8 and 9 coal seams of the Taiyuan Formation in the Shenfu block in the northern portion of the eastern margin of the Ordos Basin. Using data from sonic logging, density logging, injection/falloff well tests, and production, this study systematically analyzed the mechanical …
Numerical Simulations Of The Evolutionary Patterns Of Multi-Physical Fields During The In-Situ Pyrolysis Of Tar-Rich Coals, Yang Fu, Cheng Xiangqiang, Li Mingjie, Wu Zhiqiang, Wei Jinjia, Cao Husheng
Numerical Simulations Of The Evolutionary Patterns Of Multi-Physical Fields During The In-Situ Pyrolysis Of Tar-Rich Coals, Yang Fu, Cheng Xiangqiang, Li Mingjie, Wu Zhiqiang, Wei Jinjia, Cao Husheng
Coal Geology & Exploration
Objective The in-situ pyrolysis of tar-rich coals, an emerging technology for coal resource utilization characterized by cleanliness, high efficiency, and safety, is still in its initial development stage. This technology is greatly influenced by the evolutionary patterns of multi-physical fields and critical process parameters. Methods A numerical simulation model involving multi-physical fields was established by coupling fluid flow, heat transfer, and chemical reactions, and its reliability was verified by comparing the numerical simulation results with the pyrolysis experimental results of cylindrical coal samples. Based on the pilot test conditions, the impacts of permeability, heat-carrier flow rate, and fracture zone height …
Implementation And Numerical Simulation On Object-Oriented Elastic-Plastic Finite Element Method Based On Python, Henghui Li, Yingxiong Xiao
Implementation And Numerical Simulation On Object-Oriented Elastic-Plastic Finite Element Method Based On Python, Henghui Li, Yingxiong Xiao
Journal of System Simulation
Abstract: With the continuous expansion of the application fields of finite element methods, higher requirements are put forward for the scalability of finite element methods. In order to overcome the defects of the traditional finite element methods, a simple and easily extensible object-oriented elasticplastic finite element program framework is proposed based on Python. Combined with the characteristics of Python, we design some finite element classes such as the pre-processing class, the post-processing class, the linear solution class, the stress integration class and the analysis class. By applying the resulting framework to several typical elastic-plastic mechanical problems and comparing the results …
Three-Dimensional Forward Modeling Using The Transient Electromagnetic Method Under Complex Terrains And The Analysis Of Terrain Effects, Qu Shaobo, Zhu Jiao, Jiang Zhihai, Li Maofei, He Zhilong
Three-Dimensional Forward Modeling Using The Transient Electromagnetic Method Under Complex Terrains And The Analysis Of Terrain Effects, Qu Shaobo, Zhu Jiao, Jiang Zhihai, Li Maofei, He Zhilong
Coal Geology & Exploration
The ground-based transient electromagnetic method (TEM), with unique advantages, has been extensively applied for hydrogeological exploration in coal mines. However, in field exploration, complex terrains tend to cause variations in geometric shapes of transmitting sources and deviations in signals received, reducing exploration accuracy. Hence, by integrating theoretical analysis and numerical simulations with the analysis of actual terrain data, this study systematically investigated the response characteristics of electrical- and magnetic-source TEM fields under complex terrains. Using the vector finite-element electromagnetic forward modeling technique based on second-order backward Euler discretization, this study delved into the laws of influence of peak and valley …
Response Mechanism Characteristics Of Mining-Induced Fault Activation, Sun Wenbin, Hao Jianbang, Dai Xianzheng, Kong Lingjun
Response Mechanism Characteristics Of Mining-Induced Fault Activation, Sun Wenbin, Hao Jianbang, Dai Xianzheng, Kong Lingjun
Coal Geology & Exploration
In the process of coal mining, mining-induced stress perturbation is a key factor leading to fault activation, which is a primary challenge faced by safe coal mining. Fault activation is prone to induce geological disasters such as rock bursts and floor water inrushes of coal mines. Furthermore, it poses a serious threat to mining safety. Using the Flac3D software for numerical simulations and similar material simulation experiments, this study established a model for faults’ stress-displacement responses under coal mining to analyze the mechanisms behind the evolution of fault structure zones in the process of coal mining. Key findings are …
Numerical Simulation On Influence Of Skin Effect On Groundwater Flow Velocity In Wellbore, Wang Qihang, Li Xu, Guo Qiang, Kuai Dawei
Numerical Simulation On Influence Of Skin Effect On Groundwater Flow Velocity In Wellbore, Wang Qihang, Li Xu, Guo Qiang, Kuai Dawei
Coal Geology & Exploration
Groundwater flow velocity in wellbore is usually measured by single-well tracking tests or Aqua Vision flow velocity and direction meters to calculate the groundwater flow velocity in the aquifer. Due to the impact of the skin structure, the groundwater flow field near the wellbore changes, causing a difference between the flow velocity in the wellbore and that in the aquifer. In order to investigate the influence of the skin effect on the groundwater flow velocity in the wellbore, a numerical model of groundwater flow that considers the skin effect was established using the COMSOL Multiphysics software. On this basis, the …
Influencing Factor Analysis And Optimization Of Heat Extraction Performance Of Moderately Deep Coaxial Borehole Heat Exchangers In Northern Shaanxi, China, Zou Haijiang, Li Yongpeng, Zhang Lin, Hui Peng, Liu Houning, Shen Fang, Wang Fenghao
Influencing Factor Analysis And Optimization Of Heat Extraction Performance Of Moderately Deep Coaxial Borehole Heat Exchangers In Northern Shaanxi, China, Zou Haijiang, Li Yongpeng, Zhang Lin, Hui Peng, Liu Houning, Shen Fang, Wang Fenghao
Coal Geology & Exploration
The geothermal heating technology utilizing moderately deep coaxial borehole heat exchangers (MDCBHEs) has emerged and found extensive applications in urban heating in northern China. Despite abundant geothermal resources, northern Shaanxi exhibits slightly low geothermal gradients and distinct thermophysical properties of rocks and soils. Therefore, geological parameters influence the heat transfer performance of MDCBHEs in this area. Using OpenGeoSys, an open-source numerical simulation platform, this study established a three-dimensional calculation model for heat transfer between a MDCBHE and surrounding strata. Based on typical geological parameters in northern Shaanxi, the study investigated the influence of various design parameters on the heat transfer …
Evaluating The Exploitation And Utilization Prospects Of Hot Dry Rock In Bohai Bay Basin: Understanding Based On Numerical Simulations For Exploitation Optimization, Jiang Xiaoxue, Zhu Chuanqing, Ding Rui, Xie Fang, Qiu Nansheng
Evaluating The Exploitation And Utilization Prospects Of Hot Dry Rock In Bohai Bay Basin: Understanding Based On Numerical Simulations For Exploitation Optimization, Jiang Xiaoxue, Zhu Chuanqing, Ding Rui, Xie Fang, Qiu Nansheng
Coal Geology & Exploration
The Bohai Bay Basin, characterized by high terrestrial heat flow, formation temperatures average of 175℃ at a depth of 5000 m, and reservoirs with lithologies dominated by low-porosity and low-permeability metamorphic and igneous rocks, meets the requirements for the formation of hot dry rock (HDR) resources. Based on geothermal parameters such as terrestrial heat flow, rock thermal conductivity, and heat production rate, this study established a three-dimensional HDR exploitation model with thermo-hydro coupling using the COMSOL software. Furthermore, this study analyzed the effects of spacing between production and reinjection wells, reinjection and production rates, and well arrangement mode on the …
Sensitivity Analysis Of Development Parameters On The Production Temperature Of Karst Geothermal Reservoirs: A Case Study Of The Qingfeng Area In Henan, China, Han Yun, Li Kewen, He Jifu, Wang Xinwei, Gao Nan’An
Sensitivity Analysis Of Development Parameters On The Production Temperature Of Karst Geothermal Reservoirs: A Case Study Of The Qingfeng Area In Henan, China, Han Yun, Li Kewen, He Jifu, Wang Xinwei, Gao Nan’An
Coal Geology & Exploration
The temperature of produced geothermal water serves as a pivotal indicator influencing the efficiency of geothermal energy utilization, with a higher temperature corresponding to more effective geothermal reservoir exploitation. For karst geothermal reservoirs, recognized as a significant type of geothermal reservoir, the temperature of produced geothermal water is influenced by reservoir parameters. Focusing on the Ordovician karst geothermal reservoirs in the Qingfeng area, Henan Province, this study established a geological model of the reservoirs, followed by numerical simulations based on thermal flow and well-reservoir coupling using the data of seven geothermal wells. The purpose is to explore the effects of …
Effects Of Fracture Distribution On Heat Extraction Through Co2-Egs, Zhou Qing, Liao Jianxing, Xu Bin, Yao Liang, Zhou Haoyu, Zhao Quan
Effects Of Fracture Distribution On Heat Extraction Through Co2-Egs, Zhou Qing, Liao Jianxing, Xu Bin, Yao Liang, Zhou Haoyu, Zhao Quan
Coal Geology & Exploration
Geothermal energy, a promising source of renewable energy, has attracted considerable attention. In deep geothermal reservoirs, complex fracture networks formed by artificial stimulation provide predominant channels for heat extraction. Therefore, the spatial distribution of fractures directly affects the heat extraction efficiency. This study aims to explore the effects of different spatial distributions of fractures on the heat recovery performance. Based on the fracture network following a power-law distribution, this study systematically investigated the effects of the fracture network with different values of fracture length index (a) and density (β) on the heat recovery performance of a …
Heating Experiments Of A Solar-Assisted Heat Pump And Thermal Equilibrium Simulations Of Geothermal Fields, Jia Zilong, Zheng Jia, Zhang Yaobin, Chen Ke, Liu Aihua, Li Juan
Heating Experiments Of A Solar-Assisted Heat Pump And Thermal Equilibrium Simulations Of Geothermal Fields, Jia Zilong, Zheng Jia, Zhang Yaobin, Chen Ke, Liu Aihua, Li Juan
Coal Geology & Exploration
This study aims to explore technologies required for clean energy heating by means of multi-energy complementation, with the purpose of meeting the demand for clean heating in decentralized buildings in Beijing's villages and towns. To this end, this study built a solar-ground source heat pump (SGHP) compound system in a rural area of Beijing. Then, it carried out heating experiments of the solar-assisted heat pump system and thermal equilibrium simulations of geothermal fields using the COMSOL software. The results are as follows: (1) Compared to a single SGHP system, the solar-assisted heat pump scheme increased the outlet water temperature on …