共查询到18条相似文献,搜索用时 140 毫秒
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金属非金属地下矿山掘进巷道钻孔、爆破、铲装等作业工序产生大量岩尘,导致井巷空间粉尘浓度高,危害职工健康和影响作业环境。以某金矿掘进巷道为研究对象,建立掘进巷道压入式通风模型,依据气固两相流理论,结合现场测定数据,利用Fluent软件分析风筒布不同布置条件下除尘效果,得出巷道内粉尘运移规律和风速分布情况。研究发现:风机压入风流在掌子面附近形成涡流,携带粉尘在掌子面附近涡旋,不利于粉尘的排出,风筒布出口距掌子面7~8 m风流逐渐稳定流向回风巷;当风筒布出口距掌子面8 m,高度为1.5 m时,巷道内粉尘排出较快,除尘效果最为理想。研究结果对指导掘进工作面粉尘防治具有一定的指导意义。 相似文献
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为了改善独头掘进巷道高温环境,以大红山铜矿西矿段-20 m中段北沿脉西侧高温独头掘进巷道为研究对象,利用Fluent进行数值模拟,开展了风筒高度、抽出式风筒滞后压入式风筒距离及抽压比对独头巷道人工制冷降温效果的影响研究。结果表明:压入式风筒高度对降温效果影响明显,最佳高度为1.0 m;抽出式风筒与压入式风筒高度持平时,降温效果最好,最佳高度为1.0 m;抽出式风筒滞后压入式风筒距离过大不利于降温,最佳距离为5.0 m;抽压比过小或过大均不能使掘进巷道形成良好的风流循环,降温效果较差,最佳抽压比为2.0。研究成果可为高温矿井通风辅助人工制冷降温参数选取提供指导。 相似文献
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矿井火灾已成为矿山安全生产过程中重点关注的问题之一,尤其高原地区受制于复杂的环境因素,火灾时期的抢险救灾成为难题,因此研究海拔高度对火灾烟气传播规律的影响具有重要的实践意义。采用火灾数值模拟软件FDS,对5种不同海拔高度(0,1000,2000,3000,4000 m)下矿井巷道火灾进行动态模拟,通过观察烟气扩散和动态升温过程,分析不同海拔高度下烟气扩散和温度分布规律,并对比不同海拔高度下矿井巷道内温度、烟气行为(CO浓度)和能见度等参数的变化情况,据此分析海拔高度对矿井火灾时期人员安全疏散的影响。结果表明:火灾烟气蔓延速率随着海拔高度的增加而减小,且高海拔地区减小幅度更大;随着海拔高度的增加,火灾蔓延过程中产生的顶峰温度和CO浓度值均减小,且能见度增强,对人体产生的危害也相应减小。总体来说,当海拔相对较高的矿井发生火灾时,相较于正常海拔地区,安全疏散时间延长,安全疏散距离缩短,更有利于人员逃生。 相似文献
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为探明矿井掘进巷道火灾时人员应急疏散情况,给矿井掘进巷道内避难硐室的合理设置提供参考。通过Pyrosim火灾仿真模拟软件和Pathfinder人员疏散仿真模拟软件对矿井掘进巷道仿照真实情况分别进行建模,在Pyrosim模型中掘井巷道与联通巷交汇处高1.6 m设置8个烟雾探测器,在Pathfinder模型中设置3种不同布置的避难硐室,得出掘进巷道火灾、烟雾蔓延规律以及3种情况下人员应急疏散结果。研究发现:火灾发生后烟雾迅速在掘进巷道内蔓延开来,人员在3种情况下疏散的时间依次为232,123,55 s,比较火灾时各烟雾监测点的TASET与3种情况下相同位置的TRSET,只有情况3时避难硐室的设置才能够满足全部人员安全疏散。矿井掘进巷道避难硐室的修建要跟上掘进巷道深度的推进,且避难硐室的间距应控制在100 m以内。 相似文献
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水平坑道掘进,利用局部扇风机进行通风时,由于各个时期对通风的要求不同,而需要改变通风方式,即进行反风。例如:爆破后为了迅速的排除爆破所产生的有害气体,采用抽出式的通风方式是合理的,但是,当坑道掘进进行运搬作业时,为了保证供应足够的新鲜空气送达工作面,不能停止扇风机运转,并以压入式通风较为可靠合理。我矿通风工王庆奎同志创造性的解决了局扇的反风问题,茲将王庆奎同志提出的并经改进后的反风装置介绍如下(参看附图):反风装置由铁风筒1、2、3、5、6、段,帆布风筒4及用膠皮做成的密闭盖7、8组成。图示实线位置是压入式通风状态。风筒6及3两端均用密闭 相似文献
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通过数值模拟分析了巨龙铜矿平行巷道掘进过程中,断层破碎带与巷道间距对钻爆法掘进巷道围岩稳定性的影响。建立了不同巷道与断层破碎带间距下数值模拟计算模型,分析了围岩位移场、应力场及塑性区变化规律。数值模拟结果表明:巷道与断层破碎带间距为1 m和4 m时,断层破碎带对巷道围岩稳定性影响较大,巷道边帮最大位移值为6.19 cm和1.13 cm;最大主应力集中在巷道左侧围岩内,右侧围岩应力较小;水平方向应力集中在围岩与断层破碎带交界处;断层破碎带内出现塑性变形。当巷道与断层破碎带间距为7 m和10 m时,断层破碎带对巷道围岩稳定性影响较小,最大主应力与水平方向应力沿巷道中线近似对称分布,断层破碎带内无塑性变形。 相似文献
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随着我国煤矿开采深度不断增加,矿山压力显现成为制约煤矿安全生产的主要因素,特别是沿空掘进巷道受邻近采空区侧向支撑压力影响,矿山压力现象明显,造成沿空掘进施工困难,安全风险大,基于煤层赋存条件,通过对沿空掘进期间矿压显现情况研究,针对不同矿压类型,探索治理措施,降低掘进施工难度,提高掘进施工安全系数。 相似文献
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提出了一种基于元胞自动机的井巷火灾可视化仿真方法.在矿井巷道可视化的基础上,通过对火灾元胞进行表征,综合考虑可燃物类型与投放密度、井巷通风、井巷坡度等因素对井巷火源引燃效果的影响及双扩散作用、井巷通风、浮力作用和节流作用等因素对火灾烟气蔓延效果的影响,采用概率函数进行元胞自动机建模,构建了表达元胞温度的井巷火源燃烧模型和表达元胞浓度的井巷火灾烟气蔓延模型.基于火源元胞燃烧演化规则和烟气元胞蔓延演化规则,通过可视化手段展示了井巷火灾火源燃烧和有害气体浓度的时空发展变化.同时以矿山实际数据进行检验,说明了基于元胞自动机的井巷火灾仿真的可行性与有效性. 相似文献
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隧道通风过程中空气湿热状态变化研究 总被引:1,自引:1,他引:0
隧道及巷道等地下工程在施工及运营阶段需要以自然或机械通风设施等方式进行通风,以保持充足的新鲜空气量,并维持其内人员的舒适感。当前大多研究集中在隧道通风过程中的空气质量以及烟雾透过率,而较少关注通风过程中空气的湿热状态的变化。以热力学及流体力学的基本理论为基础,研究地下隧道长距离、大规模地下输送新鲜空气过程中,隧道内空气湿热状态的变化。通过论证,在经过隧道长距离输送后,空气湿热状态参数发生较大变化。这说明,空气在地下输送过程中,尽管有风机做功以及摩擦生热过程,但在恒温层的保温作用下,温度只会略有上升;而湿度则会升至饱和状态。这将对地下储库、地下采矿等地下工程的空气调节系统设计研究工作有一定指导意义。 相似文献
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针对隧道射流通风存在功率利用率低,大浓度尾气调控不理想等问题,运用FLUENT软件,以模拟优化瓮福磷矿隧道的通风系统问题为实例,将射流风机和空气幕引射风流进行风流对比,提出引射风流空气幕替代射流风机加强隧道通风的全新命题。研究结果表明:两种优化风机组合都能达到隧道所需的通风标准,在进行对比过程中,如果总功率一样,引射风流空气幕组合产风量大于射流风机组合,而总功率145.5 kW空气幕组合可产生与总功率180 kW射流风机组合类似的通风效果,且总功率可节约34.5 kW。在风机组合优化过程中,各风机功率分配越平均对风机组合通风效率提升越大,同种功率的风机两两并联,通风效果要优于不同功率风机两两并联。 相似文献
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Numerical studies on hot smoke tests at an airport terminal were performed. In that airport terminal, field measurements on the smoke filling process with and without operating the ventilation system were carried out in the actual site, giving sufficient experimental results for verifying fire models. In this paper, a fire field model is assessed. The computational fluid dynamics program selected was CC-EXACT, a package modified from the EXACT program developed by the National Institute of Standards and Technology. The fire was taken as a heat source with two sets of numerical simulations carried out. The first set was on natural smoke filling for understanding the smoke filling process when the ventilation system is shut down. The second set was on assessing the performance of the mechanical ventilation system. Results predicted by the field model are compared with those measured at the site. It is found that results predicted from this computational fluid dynamics program agreed reasonably well with those experimental data. Therefore, the model is good enough for studying the smoke filling process in large halls. 相似文献
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A three-dimensional large-eddy-simulation computational fluid dynamics (CFD) program, developed for studying the transport of smoke during a fire in an enclosure, is applied to four flow problems relevant to nonfire situations. This evaluation is relevant to the use of the program for indoor air quality modeling as well as its use in modeling the early phases of smoldering fires. The program uses finite-difference techniques to solve the Navier-Stokes equations, with an approach emphasizing high spatial resolution and efficient flow-solving techniques. Subgrid scale effects are addressed with the Smagorinsky model. The flow problems include simple geometries, with forced, natural, and mixed convection flows as well as a realistic test room with a displacement ventilation system and tracer gas release. Grid effects and computing time are investigated. Results are compared with the experimental data, and issues important to defining the problems in CFD are highlighted. In general the program predicts the experimental data reasonably well, with very fast computing times. However, care must be taken in defining convection from heated surfaces, and adequate grid resolution is needed to model the dispersion of a tracer gas in the enclosure. 相似文献
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Ron Johnson Jack Schmid Satish Dinakaran Rich Seifert 《Canadian Metallurgical Quarterly》2005,19(1):3-18
Interior Alaska has indoor air quality (IAQ) issues similar to those of other far northern communities associated with long cold winters and reduced ventilation rates. We also have some interesting issues associated with elevated radon in homes built in the hills around Fairbanks, as well as elevated particulate levels created by smoke from forest fires that occur in the vast uninhabited portions of the state. To better understand the influences of critical variables such as indoor source strengths and ventilation rates on IAQ associated with forest fires and radon, we have developed a Simulink-based mass conservation model. Using data gathered at two homes in Fairbanks during 2003, we have used this model to predict indoor radon and PM2.5 levels (particles less than 2.5?μm in diameter). We find that we are able to predict both the rise of radon following the shutdown of a radon mitigation system and the variation of indoor PM2.5 by using ventilation rates consistent with what we have measured, PM2.5 source strengths associated with individuals in residences, and penetration and deposition rates compatible with what others have found. We have used situation-specific algorithms for subsurface radon source strength as well as particulate generation associated with cooking. 相似文献
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庙岭金矿井下采空区规模庞大,大量的废弃巷道和未处理采空区,导致井下通风风流紊乱、漏风量大、通风效果差、主扇运转效率低。基于变权重与可变模糊集耦合模型对现有复杂采空区进行了稳定性风险评估,通过对安全风险较大的采空区进行充填治理、对风险一般的采空区和废弃巷道进行封闭,大大减少了漏风和串风现象。增设459 m平硐作进风通道,将原单翼对角式通风系统优化为双翼对角式通风系统,大大缩短了通风线路,改善了进风质量。基于Ventsim的矿井通风网络模拟与仿真,解算了容易时期和困难时期机械通风所需的风压。在充分利用现有风机和新增少量采掘工程的基础上,有效改善了风流质量,保障了通风效果,节约了系统改造投资成本。 相似文献