1、 毕毕 业业 设设 计计(论文论文) 系 别 动力工程系 专业班级 环境工程 班 学生姓名 指导教师 二一三二一三年六月年六月 题 目 燃煤锅炉燃烧过程流 场及温度场数值模拟 I 摘 要 数值模拟是以电子计算机为手段，通过数值计算和图像显示的方法，达到对工程问题 和物理问题乃至自然界各类问题研究的目的。课题涉及到三维燃烧过程，并带有两相流。 综合考虑，我选择了目前应用比较广泛的 FLUENT 软件作为数值模拟的工具。 本文对锅炉炉膛计算域通过 GAMBIT 软件构建三维框架结构， 从而对其进行网格划分， 确定合适的数学物理模型，设置边界条件，选用适当的变量和参数，对炉膛燃烧进行三维 数值模拟，
2、得出炉膛内流场与温度场分布。最后经过简单的处理，将模拟结果以图片或图 表的形式进行直观的展示。 通过对模拟结果的观察分析得出合理的结论， 并分析不足之处。 改变燃尽风风速大小，选择 30m/s、40m/s、49m/s 及 60m/s 三种燃尽风速，研究燃尽风风 速对炉内混合特性和炉内温度场的影响。结果表明:燃尽风口风速增大时，炉内气流的旋 转强度随之增强，燃尽风的穿透程度随之加强，相对容易穿透到炉膛中心，从而使得烟气 与煤粉的混合加剧，有利于增加煤炭燃烧的效率；在一定条件下，随着燃尽风速的增加， 炉膛中心的高温区域面积增加，而且相对集中；随着燃尽风速的增加，锅炉烟气出口的温 度降低；燃尽风风速
3、为 49m/s 时炉内燃烧状况最佳。 关键词：流场；温度场；数值模拟；燃尽风 II NUMERICAL SIMULATION ON FLOW FIELD AND TEMPERATURE FIELD OF THE COMBUSTION PROCESS IN THE FIRED PULVERIZED-COAL BOILER Abstract Numerical simulation uses electronic computers as the means. To achieve the purpose of engineering problems and physical problems
4、as well as the nature of various problems, it uses the method of the numerical calculation and image shows. The topic relates to the three-dimensional combustion process and the two-phase flow. Considered, I chose the FLUENT as the tool for numerical simulation. In this paper, establishing the three
5、 dimensional frame construction with GAMBIT, carrying on the grid division, then selecting the appropriate model of mathematics and physics and the suitable parameter and the variable, setting up the boundary condition, making three-dimensional numerical simulation of furnace combustion, receiving t
6、he distributions of flow field and temperature field in the furnace. After simple processing, we can show the result by making the pictures or diagrams. Making a conclusion from the results and finding out the inadequacies of the results. Changing the size of velocity of over fired air，choose 30,40,49 and 60 meters per second，then discuss what will happen about mixing characteristics of the furnace and temperature field.Study results indicate that As burnout air speed increases, the rota
