接触网供电下区间隧道内地铁颗粒物受力分析及数值研究

分类号 X511 单位代码 10618 密 级 公开 学 号 2150084001 硕士学位论文接触网供电下区间隧道内地铁颗粒物受力分析及数值研究 研 究 生 姓 名： 庞宏波 导师姓名及职称： 张慧玲（副教授） 申请学位类别 工学硕士 学位授予单位 重庆交通大学 一级学科名称 土木工程 论文提交日期 2018年4 月16 日二级学科名称供热、供燃气、通风与空调工程 论文答辩日期 2018年 6月 7 日2018 年 6 月 8 日1Force Analysis and Numerical Study of Subway Particles in Underground Tunnel under Power Supply of CatenaryA Dissertation Submitted for the Degree of MasterCandidate：Pang HongboSupervisor：Prof. Zhang Huiling Chongqing Jiaotong University, Chongqing, China1摘 要地铁颗粒物作为地铁环境中特殊的污染物，浓度水平更高，元素组成更复杂，对人体的毒害性更强，因此研究地铁颗粒物具有重要意义。本文将区间隧道作为主要研究范围，以地铁颗粒物为主要研究对象，针对目前地铁颗粒物研究存在的不足，首先从理论研究的角度出发，基于既有文献和实验结果，分析了地铁颗粒物的尘源，初步确定了地铁颗粒物在列车不同行驶阶段的发尘速率，建立了区间隧道内颗粒物质量浓度平衡方程；其次依据前人对地铁颗粒物的元素分析数据和浓度实测结果，按粒径确定了地铁颗粒物的真密度均值，基于气固两相流理论，详细分析了地铁颗粒物的受力情况；最后采用数值模拟的方法，运用DPM模型得到了列车在不同行驶阶段以不同车速运行时的地铁PM10模拟结果，重点讨论了地铁颗粒物的扩散情况和浓度分布，对比了不同阶段下颗粒在空调机组周围的浓度分布，以及颗粒的运动轨迹。通过本文的研究，主要得到以下结论：1、区间隧道环境主要受内部来源即磨损颗粒的影响，其尘源可以分为制动、轮轨和弓网磨损颗粒。列车运行需经历匀速行驶、制动初期和制动后期三个阶段，不同行驶阶段具有不同的内部尘源项组合和发尘量强度。2、地铁颗粒物的真密度值随粒径的不同而变化，地铁PM10、PM2.5和PM1的密度均值分别为4.043g/cm3、3.766g/cm3和2.562g/cm3。颗粒受力情况不能一概而论，对于地铁PM1，主要作用力仅考虑曳力和Brownian力；对于地铁PM2.5颗粒，主要作用力需要考虑曳力、Brownian力和重力；对于地铁PM10，主要作用力包括重力、曳力、Brownian力和Saffman力均不能忽略。3、不同内部尘源磨损颗粒具有不同的扩散形式和浓度值分布。弓网磨损颗粒以带状和椭圆块状的形式在隧道上部空间扩散，其在列车周围以及列车后方隧道内的浓度值分别都随着车速的降低而减小；轮轨和制动磨损颗粒以条状形式在隧道下部空间扩散，其上述区域内的混合浓度值分别都随着车速的降低而增大。4、不同行驶阶段下，区间隧道各截面具有不同的颗粒浓度特征。匀速行驶阶段，各截面浓度峰值均较高，颗粒主要悬浮于列车后方的隧道区域中；制动初期阶段，各截面浓度峰值比较接近，颗粒均匀悬浮于列车周围及其后的隧道内；制动后期阶段，各截面浓度峰值较为分散，颗粒主要悬浮和沉积于列车周围。5、不同行驶阶段下，列车车载空调机组附近存在不同的浓度分布情况。匀速行驶阶段以及制动后期阶段，列车车载空调机组两侧新风口不存在浓度分布，颗粒对车厢内空气质量几乎无影响；制动初期阶段，机组左则或右侧新风口都出现了贴壁分布的低浓度区域，浓度范围在7.32×10-9kg/m3 2.32 ×10-8kg/m3之间， 颗粒对车厢内空气质量会产生一定影响。6、不同内部尘源颗粒具有不同的过滤设备最佳安装位置。针对轮轨磨损颗粒或者制动磨损颗粒，相应的过滤设备则应装置于列车尾部车厢底部或后方；针对弓网磨损颗粒，相应的过滤设备应装置于隧道顶部空间。关键词：区间隧道；地铁颗粒物；密度；受力情况；扩散；浓度ABSTRACTAs a special pollutant in subway environment, subway particles have higher concentration level and more complex element composition, which is more toxic to human body. Therefore, it is of great significance to study the subway particle.The underground tunnel is chose as main research range and subway particle is selected as main object.This article is aimed at the shortcomings existing in present research of subway particles. At first, from the perspective of theoretical research, based on existing literature and experimental results, dust sources and generating rates of subway particles are analysed and determined. The balance equation of mass concentration is established, Element composition of subway particle is listed and the density value is distinguished according to particle sizes. Based on theory of gas-solid two-phase flow, the force condition of particle is analyzed and verified. Finally, from the perspective of numerical study, the simulation results of subway PM10 under different train speed in different running status by utilizing DPM model. Diffusion status and concentration distribution of subway particle is discussed. At the mean time, particle trajectories and concentration distributions around the air conditioning under different train speed is compared. Through the study of this paper, the main conclusions are drawn as follows:1、The underground tunnel environment is mainly influenced by internal source, namely, the wear particles, which include braking, wheel-rail and pantograph-catenary wear particles. There are three phases in the course of a running train in a tunnel, that is, phase of uniform speed, earlier phase of braking and later phase of braking. Meanwhile, The dust source combination and the dust intensity are different at every phase.2、The densities of subway particles vary with particle size. For subway PM10, PM2.5 and PM1, the mean density is 4.043g/cm3, 3.766 g/cm3 and 2.562 g/cm3. Force condition of the particles cannot be generalized. For subway PM1, only Brownian force and drag force are considered. For subway PM2.5, Brownian force, dragforce and gravity should be considered. For subway PM10, all the major forces, including Brownian force, dragforce, gravity and Saffman force cant be ignored.3、The wear particles of different internal dust sources have different diffusion forms and concentration values. Pantograph- catenary wear particles diffuse at the upper part of tunnel in the form of belt and elliptical lump. Concentration value of the particles reduce gradually with decrease of vehicle speed in zone around the train and behind the train. Wheel-rail and the brake wear particles diffuse at the lower part of the tunnel in the form of strip. The mixing concentration value increases gradually with the decrease of vehicle speed in above zones. 4、Under different running phases, every section of under