褐煤流化床干燥器布风板的数值模拟与结构优化

发布时间：2018-04-19 21:08

本文选题：褐煤 + 流化床干燥器　；参考：《中国矿业大学》2015年硕士论文

【摘要】：褐煤通过流化床干燥是其提质的重要方式,对流化床来说,布风板结构对流化质量优劣起着决定性的作用。布风板结构形式多样,但用于干燥的流化床设备因特殊的高温条件,布风板依旧以初始阶段的直孔或斜孔型为主。本文针对用于干燥流化床布风板现状,对其结构提出多种改进措施。以布风性能优良的侧流型布风板和加工制造廉价的直孔型布风板为基础,结合两种类型布风板的特性和优势,创新性地设计出四种新型布风板结构,分别命名为普通斜孔型布风板、旋转斜孔型布风板、六角对吹斜孔型布风板和伞型帽板分离型布风板。建立安装四种不同结构布风板的流化床三维模型、合理划分网格、确定数值模拟方法和边界条件后,用FLUENT软件对四种结构开展单相流三维模型数值模拟,得到了一系列模拟结果且通过压降实验验证模拟结果的正确性。通过对比分析气流速度矢量图形、轴向压降、径向静压曲线和气流分布形态等参数认定伞型帽板分离型布风板为四种创新性结构中的最佳结构,再通过褐煤干燥热态实验,对比安装四种布风板流化床在相同参数下的褐煤干燥效率和干燥均匀度两个参数,实验结果证明安装伞型帽板分离型布风板的流化床无论是褐煤干燥效率还是干燥均匀度均是最佳,确定最佳结构为伞型帽板分离型布风板。针对伞型帽板分离型布风板进行了开孔率研究,开孔率分别为2.24%、5.04%和8.95%。分别对安装此三种开孔率布风板的流化床模型开展气固两相流二维数值模拟,对比压降波动均方根(RMS)、颗粒分布和气固相速度矢量图形等参数确定最佳开孔率为2.24%,然后通过对比安装三种不同开孔率布风板的流化床的褐煤干燥效率,实验结果表明三种中2.24%对于伞型帽板分离型布风板为最佳开孔率。
[Abstract]:The drying of lignite in fluidized bed is an important way to improve its quality. In the fluidized bed, the structure of the fluidized bed has a decisive effect on the quality of the fluidized bed. The structure of the air cloth plate is varied, but the fluidized bed equipment used for drying is still dominated by the initial straight hole or the oblique pass because of the special high temperature conditions. A variety of improvement measures are put forward for the structure of the dry fluidized bed air cloth plate. On the basis of the side flow pattern plate with excellent wind performance and the manufacturing and manufacturing of the cheap straight hole type cloth wind plate, combined with the characteristics and advantages of the two types of wind sheet, the structure of the four new type of wind sheet is designed, which are named as the ordinary inclined hole type sheet. A rotating inclined hole type cloth wind plate, six angles to the blowing plate and the parachute cap plate separation type air plate. The three-dimensional model of the fluidized bed is set up and installed with four different structures of the wind plate. The numerical simulation method and the boundary condition of the numerical simulation method and the boundary condition are set up. The FLUENT software is used to simulate the three-dimensional model of the single phase flow with the four structures. A series of simulation results are used to verify the correctness of the simulation results. By comparing and analyzing the parameters of the velocity vector graphics, axial pressure drop, radial static pressure curve and air distribution pattern, the best structure of four kinds of innovative structures is found in the umbrella type cap plate separation type. The drying efficiency and Drying Uniformity of four kinds of wind sheet fluidized bed with the same parameters are two parameters. The experimental results show that the best structure is the drying efficiency of brown coal and the evenness of drying, and the best structure is the separation type air plate of the umbrella type cap plate. The opening rate is studied. The opening rate is 2.24%, 5.04% and 8.95%. respectively. The two dimensional numerical simulation of gas solid two phase flow is carried out respectively on the fluidized bed model of the three kinds of open hole rate sheet. The optimum opening rate is determined by comparing the pressure drop mean square root (RMS), the particle distribution and the gas solid velocity vector figure to determine the optimum opening rate. The drying efficiency of three kinds of fluidized bed lignite with different opening rate is compared. The experimental results show that the optimum opening rate is 2.24% for the parachute type cap plate separation type air plate in the three kinds.

【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ051.13;TQ536

【参考文献】