井巷围岩对风流调热能力模拟研究

发布时间：2018-06-23 11:13

本文选题：井巷围岩 + 调热能力　；参考：《西安科技大学》2017年硕士论文

【摘要】：随着矿井开采深度的加大,高温热害问题日益突出。国内高温矿井热害防治普遍采用制冷降温系统,而且多数制冷设备从国外引进,降温费用较高。同时,普通矿井具有的“冬暖夏凉”现象表明井巷围岩对风流具有明显的热调节作用。掌握围岩对风流热调节规律是制定经济高效降温方案的基础,因此对井巷围岩调热能力大小进行研究有重要意义。研究了入口风温变化下井巷围岩调热能力数值求解模型。采用有限差分法,在井巷轴向和径向上划分单元,通过时间离散为轴向单元入口引入以时间序列记录的风温值,以此建立了入口风温变化下井巷围岩温度场数值求解模型,采用C#语言开发了相应的软件,该软件可进行井巷围岩对风流调热能力模拟研究。模拟研究了井巷围岩调热能力及调热能力影响因素。利用开发的井巷围岩温度场模拟软件,模拟了入口风温变化下井巷围岩温度场,分析了围岩温度场的变化规律,得出了井巷围岩温度场两区分布的真实结构:在围岩径向浅部(1区),围岩温度随季节波动;在围岩径向深部(2区),围岩温度随径向深度的延伸不断升高,直至趋近于原始岩温。进一步开展了井巷围岩调热能力影响因素研究,得出地面气温年变化幅度、井深、围岩导温系数和风量对井巷围岩调热能力的影响规律,结果表明:地面气温年变化幅度和井深对井巷围岩调热能力影响显著;围岩导温系数是影响井巷围岩调热能力不容忽视的因素;风量对井巷围岩调热能力影响甚微。建立了济三煤矿井口全风量降温热害防治系统。通过分析济三煤矿热害现状,模拟井巷围岩调热能力,为矿井热害治理拟定方案并提供依据,结果表明:一年内副井围岩累积散热量比吸热量多726477MJ,在12月围岩散热量最大,在6月围岩吸热量最大,换热量最值出现的时刻早于地面气温最值出现的时刻;采用井口全风量降温后,有效地缓解了夏季高温热害现象,副井围岩温度场两区分布特征消失,随着通风时间的延长,围岩调热圈半径逐渐向深部扩展,通风一段时间后,井底围岩调热圈半径基本不变,围岩向风流散热量逐渐减小,副井风流温升减小,井口全风量降温效果明显;当济三煤矿开采深度为1000m时,井底围岩温度场两区分布特征消除,围岩对风流热调节能力减弱,井底围岩温度不再受入口风温变化的影响,达到此开采深度,高温热害受地温影响更明显,此种情况下可考虑采用井下集中制冷降温方式治理热害。
[Abstract]:With the increase of mining depth, the problem of high temperature heat damage is becoming more and more serious. Refrigeration and cooling system is widely used in the prevention and cure of thermal hazard in domestic high temperature mine. Most refrigeration equipments are imported from abroad, and the cooling cost is high. At the same time, the phenomenon of "warm in winter and cool in summer" in ordinary mines indicates that surrounding rock of roadway has obvious heat regulating effect on air flow. It is important to study the heat regulation ability of surrounding rock in roadway because it is the basis of economic and efficient cooling scheme to master the heat regulation law of surrounding rock to wind flow. The numerical model of heat regulation capacity of surrounding rock under the change of inlet wind temperature is studied. The finite difference method is used to divide the units in the axial and radial direction of the shaft and roadway. By introducing the wind temperature recorded by time series into the inlet of the axial unit, a numerical solution model of the surrounding rock temperature field of the roadway under the change of the inlet air temperature is established. The corresponding software is developed by using C # language. The software can be used to simulate the heat regulation ability of surrounding rock of shaft and roadway to air flow. The heat regulation capacity of surrounding rock and its influencing factors were simulated. Using the developed simulation software of surrounding rock temperature field, the temperature field of surrounding rock under the change of inlet wind temperature is simulated, and the variation law of surrounding rock temperature field is analyzed. The true structure of the temperature field distribution of surrounding rock is obtained: the temperature of surrounding rock fluctuates with the season in the radial shallow part of surrounding rock (area 1), and in the radial depth of surrounding rock (area 2), the temperature of surrounding rock increases continuously with the extension of radial depth, until it approaches the temperature of original rock. The influencing factors of heat regulation capacity of surrounding rock are further studied, and the effects of annual variation of surface temperature, depth of well, coefficient of surrounding rock temperature conductivity and air volume on the heat regulation capacity of surrounding rock are obtained. The results show that the annual variation of surface air temperature and the depth of the well have a significant effect on the heat regulation capacity of the surrounding rock, the thermal conductivity coefficient of the surrounding rock is the factor that can not be ignored, and the air volume has little effect on the heat regulation ability of the surrounding rock. A system for preventing and controlling thermal damage caused by total air volume cooling at the well head of Jisan Coal Mine is established. By analyzing the present situation of heat damage in the third coal mine, simulating the heat regulation capacity of surrounding rock in the shaft and roadway, the scheme of heat damage control is drawn up and the basis is provided. The results show that the accumulated heat loss of surrounding rock of auxiliary shaft is 726477MJ more than that of heat absorption in one year, and the heat dissipation of surrounding rock is the largest in December. The maximum heat absorption of surrounding rock in June is earlier than that of surface temperature, and the phenomenon of high temperature damage in summer can be effectively alleviated by adopting the total air volume at the well head, and the distribution characteristics of temperature field in the surrounding rock of auxiliary well are disappeared. With the extension of ventilation time, the radius of the surrounding rock heat regulating circle gradually extends to the deep. After ventilation for a period of time, the radius of the surrounding rock heat regulating circle is basically unchanged, the heat emission from surrounding rock to air flow decreases gradually, and the air flow temperature of auxiliary well decreases. When the mining depth of the third coal mine is 1000m, the temperature field distribution in the bottom rock is eliminated, the heat regulation ability of the surrounding rock to the wind flow is weakened, and the temperature of the bottom rock is no longer affected by the change of the inlet wind temperature. To reach this mining depth, the high temperature heat damage is affected more obviously by the ground temperature. In this case, the underground centralized cooling and cooling method can be considered to control the heat damage.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD727.2

【参考文献】