摘 要

矿井巷道火灾具有极大的危害性，一旦发生，会对井下人员生命安全、巷道结构稳定性、财产设备以及正常的生产作业构成极大威胁。多年来的伤亡统计数据表明，矿井巷道火灾中造成人员伤亡的首要因素，就是火灾产生的高温有害烟气。而国内外前人对巷道烟气蔓延的研究，大多集中在水平的或带倾斜角度的矿井巷道，尚缺乏针对交叉口角度不同的T字形平巷内，火灾烟气蔓延规律的细致研究。

基于此点，本文采用火灾科学领域常用的计算流体力学FDS软件进行数值模拟，从烟气温度、烟气浓度和烟气层厚度三个角度，开展交叉口位于火源下风向、火源位于联络巷前段时，交叉口角度、火源功率及纵向风速变化对T字形平巷内烟气蔓延的影响规律研究。其中设计的交叉口角度包括30°、45°、60°和90°，火源功率包括3MW、5MW和8MW三种，纵向风速包括0.5m/s、2m/s和4m/s三种，研究的工况总数为8组。

结果显示，联络巷内的烟气会在交叉口附近区域出现局部淤积，并在联络巷后段逐渐恢复为正常的纵向蔓延，被进路巷抽吸的烟气会在进路巷前段区域中远离火源的一侧形成局部淤积，之后逐渐恢复为正常的纵向蔓延状态，本文据此提出了烟气纵向蔓延恢复长度的概念；交叉口角度越小，进路巷分流的烟气量越大，进路巷内整体的烟气温度、浓度和烟气层厚度越高，同时烟气在进路巷前段区域的局部淤积程度会变小，烟气纵向蔓延恢复长度也会变短；火源功率的增大会提高联络巷和进路巷内烟气的整体温度和浓度，增大联络巷内近火源区域的烟气层厚度；纵向风速越小，联络巷和进路巷内烟气层的层化稳定性越好，反之越差，在层化结构未被破坏的情况下，纵向风速的减小会降低进路巷的烟气局部淤积程度，并缩短烟气纵向蔓延恢复长度。

与此同时，本文还在对烟气蔓延规律的研究基础上，从巷道结构防护和人员疏散两方面给出了相应建议。当交叉口角度改变时，逃生人员在联络巷需要重点留意整体的下层烟气浓度和交叉口附近的烟气层高度变化，在进路巷需留意整体的烟气层高度和下层烟气浓度变化，并尽可能避开进路巷前段的烟气淤积区域；火源功率改变时，需特别注意联络巷内近火源区域的最高温升，以及进路巷烟气淤积区域的最高温升对巷道结构稳定性的影响，逃生人员需着重留意联络巷和进路巷下层烟气温度和浓度的变化，并尽可能避开进路巷的烟气淤积区域；纵向风速的提高能够降低巷道烟气整体温度，但也会破坏烟气的层化稳定性，对于本文建立的T字形平巷模型，研究结果表明三种设计的纵向风速中，0.5m/s最利于人员逃生。

之后，本文选取了联络巷中轴线以及进路巷烟气淤积侧的顶棚下方烟气温度数据，研究T字形平巷内的火灾温度分布情况。研究结果显示，对于本文设计的工况，Y.Z Li模型相比Kurioka模型能更好地预测联络巷顶棚下方的最高温升；交叉口角度的变化对联络巷顶棚下方无量纲温升的分布情况无明显影响，但进路巷的存在会使联络巷顶棚下方无量纲温升分布情况与正常的条形巷道不同，联络巷顶棚下方的无量纲温升可根据其空间分布情况划为三个区域：烟气正常纵向蔓延区（Ⅰ）、交叉口附近的烟气淤积区（Ⅱ）和烟气二次正常纵向蔓延区（Ⅲ），区域Ⅰ、Ⅱ的无量纲温升可以用指数方程很好地拟合，区域Ⅱ的无量纲温升接近常数；进路巷烟气淤积侧的无量纲温升可以用指数方程很好地拟合，指数衰减系数与交叉口角度的正弦值之间呈线性关系。

关键词：联络巷；进路巷；交叉口角度；烟气淤积；纵向蔓延；无量纲温升

ABSTRACT

Mine drift fire has great danger and harmfulness. Once it happens, it will pose a great threat to the life safety of underground personnel, support stability of drifts, instruments and equipment as well as normal borehole operation. The statistical data of casualties over the years show that the primary cause of casualties in mine drift fires is the harmful smoke caused by fire source. However, previous studies on the spread of smoke in mine drifts at home and abroad mostly focus on horizontal or inclined mine drifts. There is still a lack of detailed research on the law of fire smoke spread in T-type mine drifts with different angles of intersections.

Based on this point, the FDS software is used for numerical simulation in this paper. In terms of smoke temperature, concentration and thickness, the influence of intersection angle, fire source power and longitudinal air velocity on smoke spread in T-type drift is studied when the intersection is located at the downstream of the fire source and the fire source is located at the front of the contact lane. Design of intersection angles including 30 °, 45 °, 60 ° and 90 °, fire source power including 3 MW, 5 MW and 8 MW, longitudinal air velocity including 0.5 m/s, 2 m/s and 4 m/s.

The research results are as follows. The smoke in the contact lane will appear local deposition in the area near the intersection and gradually return to normal longitudinal spread in the back section of the contact lane. The smoke sucked by the entry lane will form local deposition on the side far away from the fire source in the front section of the entry lane, and then gradually return to the normal longitudinal spreading. The concept of “the length of smoke longitudinal spread recovery” is put forward in this paper. The smaller the angle of the intersection is, the larger the quantity of smoke shunt in the entry lane will be, the higher the overall smoke temperature, concentration and layer thickness in the entry lane will be, the smaller the local deposition degree of smoke in the front section of the entry lane will be, and the shorter the length of smoke longitudinal spread recovery will be. The increase of fire source power will increase the overall temperature and concentration of smoke in the contact lane and the entry lane, and increase the thickness of the smoke layer near the fire source in the contact lane. The lower the longitudinal air velocity is, the better the stratification stability of the smoke layer in the connection lane and the entry lane is, and vice versa. In the case that the stratification structure is not destroyed, the decrease of the longitudinal air velocity will reduce the local deposition degree of smoke in the entry lane and shorten the length of smoke longitudinal spread recovery

At the same time, on the basis of the study of smoke spreading law, this paper also gives the corresponding suggestions from the aspects of mine drift structure protection and personnel evacuation. When the angle of the intersection changes, the escape personnel in the contact lane should pay attention to the overall smoke concentration in the lower layer and the changes of the smoke layer height near the intersection, and pay attention to the overall smoke layer height and the lower smoke concentration in the entry lane, and try to avoid the smoke deposition zone in the front section of the entry lane. When the fire source power changes, attention should be paid to the influence of the Ceiling maximum temperature rise near the fire source area in the contact lane and the maximum temperature rise in the smoke deposition zone in the entry lane on the structural stability of the drift. Escape personnel should pay attention to the change of smoke temperature and concentration in the lower level of contact lane and entry lane, and avoid the smoke deposition zone in the entry lane as far as possible. The increase of longitudinal air velocity can reduce the overall temperature of the smoke in the roadway, but it will also destroy the stratification stability of the smoke. For the T-type drift model established in this paper, the numerical simulation results show that 0.5m/s is the most favorable for the escape of personnel among the three designed longitudinal air velocity.

After that, the smoke temperature data under the ceiling of the side where the smoke deposited of the entry lane, and the temperature data of the axis of the contact lane were selected to study the fire temperature distribution in the T-type drift. For the working conditions designed in this paper, Y.Z Li et.al model can better predict the maximum temperature rise under the ceiling of the contact lane compared with Kurioka et.al model. The change of intersection angle has no obvious influence on the dimensionless temperature rise distribution under the ceiling of the contact lane, but the existence of the entry lane will make the dimensionless temperature rise distribution under the ceiling of the contact lane different from the typical strip drift. The dimensionless temperature rise under the ceiling of the contact lane can be divided into three regions according to its spatial distribution: smoke normal longitudinal spreading region (Region Ⅰ), smoke deposition region near the intersection (Region II), and smoke secondary normal longitudinal spreading region (Region III), dimensionless temperature rise in the Region I.III can be well fitted by exponential line, in the Region II nearly constant. The dimensionless temperature rise under the ceiling of the side where the smoke deposited of the entry lane can be well fitted by the exponential equation, the exponential decay coefficient has a linear relationship with the sine of intersection angle ().

Key Words：

contact lane；entry lane；intersection angle；smoke deposition；longitudinal spread；

dimensionless temperature rise

目 录

摘 要 I

ABSTRACT III

第1章 绪论 1

1.1 研究背景和意义 1

1.2 国外的研究状况 1

1.3 国内的研究情况 2

1.4 本文研究内容及方法 2

第2章 T字形平巷数值模拟模型建立 5

2.1 FDS软件介绍 5

2.2 FDS模拟工况的设计与建立 5

2.2.1 工况的环境条件 6

2.2.2 工况物理模型的建立 6

2.2.3 工况燃烧模型的建立 6

2.2.4 网格划分 7

2.2.5 布置监测点与切片 8

2.3 模拟工况汇总 11

第3章 T字形平巷烟气蔓延数值模拟研究 12

3.1 T字形平巷的烟气蔓延基本特征 12

3.1.1 #4工况下联络巷烟气蔓延基本特征 15

3.1.2 #4工况下进路巷烟气蔓延基本特征 17

3.2交叉口角度对烟气蔓延的影响规律 22

3.2.1 交叉口角度对联络巷烟气的影响规律 22

3.2.2 交叉口角度对进路巷烟气的影响规律 25

3.3火源功率对烟气蔓延的影响规律 32