共查询到19条相似文献,搜索用时 156 毫秒
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为了加强采空区瓦斯的治理,需要对工作面后方采空区瓦斯流动和分布规律进行研究,本文介绍了利用CFD采空区气体流场模拟软件模拟分析瓦斯在采空区中的流动规律,通过示踪气体的CFD模拟分析掌握了13118工作面采空区瓦斯瓦斯流动规律,为工作面建立合理的通风方式以及进行采空区瓦斯抽采提供了指导依据。 相似文献
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为了描述留巷段漏风对采空区瓦斯运移规律的影响,运用UDEC离散元模拟分析了采空区碎胀系数分布特征,并以CFD理论建立数值模型,采用Fluent数值模拟软件对留巷段存在漏风情况下的采空区瓦斯运移规律进行了模拟分析,并对比分析了漏风对氧化自燃带分布范围的影响。研究表明:留巷段漏风的存在加大了工作面漏风强度,加快了采空区瓦斯向深部及倾斜方向运移速度,扩大了采空区氧化自燃带宽度,增加了采空区遗煤自燃可能性。 相似文献
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在示踪气体试验的基础上,建立了模拟综采工作面采空区空气、瓦斯流动的数学物理模型,基于VC++6.0环境下对Fluent进行二次开发,分别对工作面正常生产、回风巷侧联巷密闭不严、尾巷密闭不严和高瓦斯涌出等4种情况下采空区氧气及瓦斯的分布进行了预测研究.结果表明:采用CFD模型模拟得到的采空区气体分布规律与现场长期监测结果相吻合;回风巷侧联巷及尾巷密闭不严将极大增加采空区氧气浓度;高瓦斯涌出可以加速采空区的自我惰化,有利于防治采空区自燃. 相似文献
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为了解决采空区煤层气抽采效率低、采空区漏风、煤层自然发火等问题,建立了采空区流场和温度场耦合数学模型,利用FEMLAB软件对采空区气体流场分布进行了数值模拟,分析了有无抽采对采空区煤层气改变氧化升温带的主要影响因素,以此研究合理的抽采位置、抽采方法、抽采量及工作面推进速度。研究发现,在推进度v=2.0 m/d下,采空区经历了缓慢氧化、加剧氧化和激烈氧化3个过程,70 d后发生采空区自燃;在推进度v=2.6 m/d下,采空区在100 d后发生采空区自燃;采空区自燃危险区域应在35~280 m,自燃氧化带宽度约为245 m。 相似文献
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Ting-xiang Ren 《煤炭学报(英文版)》2009,15(3):225-228
CFD models have been developed to investigate the longwall goaf gas flow patterns under different mining and geological control
conditions. The longwall goaf was treated as porous regions and gas flow was modelled as a momentum sink added to the momentum
equation. Gas desorption from the caved goaf and destressed coal seams within the mining disturbed area was modelled as additional
mass sources in the continuity equation. These CFD models were developed according to specific longwall layouts and calibrated
against field monitoring data. Two case studies were presented demonstrating the application of CFD modelling of goaf gas
flow characteristics for improved goaf gas capture and the reduction of oxygen ingress into the goaf areas for self-heating
prevention. Results from the case studies indicate that the optimum goaf drainage strategy would be a combination of shallow
(near the face) and deep holes to improve the overall drainage efficiency and gas purity. For gassy longwall faces retreating
against the seam dip, it is recommended to conduct cross-measure roof hole drainage targeting the fractured zones overlying
the return corner, rather than high capacity surface goaf drainage deep in the goaf. 相似文献
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The combined computational fluid dynamics and discrete element method (CFD–DEM) approach has been proved to be an effective tool to study the fundamentals of different particle–fluid flow systems, but suffers high computational cost problem. Recently, various treatments such as parcel–particle concept, coarse-grained model, similar particle assembly and representative particle model have been developed to reduce the computational cost of CFD–DEM approaches. These treatments are basically empirical and thus their applicability is likely system-dependent. Until now, there are still no general agreements on the formulation of those models and their accuracy and general applicability are largely unknown.In this work, a coarse-grained (CG) (CFD–DEM) model is developed to model the swirling multiphase flow in a dense medium cyclone (DMC) and the error caused by the CG concept is quantified by carrying out controlled numerical calculations to directly compare the simulated results between a standard CFD–DEM model and a CG CFD–DEM model. It demonstrates that when the flow is dilute, the results are independent on the size of the grain (also called as parcel or model particle in this work). Nonetheless, when the flow is dense, small discrepancies are observed between the two models. This work suggests that the CG CFD–DEM model is indeed a useful tool to quickly evaluate the flow and performance of large-scale DMCs and the simulation results should be useful at least qualitatively, if not quantitatively. 相似文献
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除尘管道湍流场特性的三维建模与数值仿真 总被引:1,自引:0,他引:1
针对除尘设备中的弯管,基于雷诺时均方程,采用Realizable k-ε湍流模式建立了CFD三维模型,应用SIMPLEC算法对管道内湍流流场评价指标进行了数值模拟。仿真结果与实验数据比较后发现,计算的压损值更接近实验结果。该模型为除尘管道的结构改进和优化设计提供了理论依据。 相似文献
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矿用离心风机流场稳态耦合仿真研究 总被引:1,自引:1,他引:0
为了研究矿用离心风机在高粉尘浓度环境下的工作情况,利用计算流体力学软件FLUENT对4-72-4A型离心风机进行了气固耦合仿真研究,应用SIMPLE算法和标准k-ε湍流模型对离心风机叶轮内部的气相流场和颗粒相运动轨迹进行了数值计算,获得了离心风机叶轮流场区域和蜗壳流场区域内的速度场和压力场,以及颗粒相的运动轨迹,对离心风机的结构优化及设计具有重要意义。 相似文献
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基于流体动力学理论,建立了回风隅角的紊流k-ε数学模型,分析了计算边界条件;并结合采煤工作面实例,应用Fluent6.0计算流体动力学软件模拟了工作面隅角的通风流场,得出了隅角有限空间内典型截面的流动规律。模拟计算结果表明,在回风隅角处风流速度很低,靠近采空区内部甚至更低,从而使采空区涌出的瓦斯不易扩散,而造成回风隅角附近瓦斯的积聚。该模拟结果为研究隅角瓦斯运移规律及解决回风隅角瓦斯积聚问题等提供了理论基础。 相似文献