本科毕业设计(论文)

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卫生洁具辊道窑烧成带温度均匀性仿真研究

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本科生院制

2015年6月

卫生洁具辊道窑烧成带温度均匀性仿真研究

卫生洁具辊道窑烧成带温度均匀性仿真研究

摘要

本文以44m卫生洁具辊道窑烧成带为研究对象，针对陶瓷制品在烧成过程中存在温度分布不均匀的问题进行了数值模拟研究，并对燃料入口速度、空燃比等主要工艺控制参数进行了优化，主要研究内容及结论如下：

（1）建立了辊道窑烧成带物理模型和数学模型，其中湍流流动采用realizable

k?ε湍流模型，燃料燃烧采用有限速率燃烧模型、辐射采用P?1辐射模型，算法采用

SIMPLE算法，控制方程的离散化采用一阶迎风格式。并基于现场测试数据，对模型进行了验证，结果表明：实测值与模拟值相对误差低于5%，模型基本可靠。

（2）对基准工况下辊道窑烧成带内温度场、流场等进行了模拟研究，结果表明：烧嘴射流最大速度为10m/s,火焰长度为300mm-500mm；射流火焰受主流烟气影响产生偏移形成有利制品换热的流体循环。受回流影响，两陶瓷制品温度均匀性略有差异。

（3）采用离散系数cv为洁具表面温度均匀性的评价指标，对燃料入口速度和空燃比两个主要工艺控制参数进行了仿真优化研究，结果表明：天然气以4.5m/s的速度喷入时，洁具温度分布均匀性最好；天然气、空气入口速度比为3.21时，洁具温度分布均匀性最好。

关键词：辊道窑 温度均匀性 卫生洁具 数值模拟

卫生洁具辊道窑烧成带温度均匀性仿真研究

Simulation studies on temperature uniformity of sanitary

ware roller kiln burning zone

ABSTRACT

This study chooses 44m roller kiln burning zone as the object, carries out the numerical simulation for the temperature uniformity problems of ceramics and optimizes the process control parameters such as fuel inlet velocity and air-fuel ratio. The main research contents and conclusions are as follows:

1) Established the physical mathematical models of burning zone, in which the turbulence model was Realizablek?ε，combustion model was the finite speed model, P-1 radiation model and SIMPLE algorithm were used, discrete equations belong to the first order upwind scheme. The models have been verified based on the real test data. The result showed that the relative error between measured value and simulated value was less than 5%.

2) Simulated and studied the reference conditions of burning zone such as temperature field and flow field. The maximum speed of the jet burner was 10m/s, the flame length was 300mm to 500mm. Effected by the mainstream gas flow, the jet flame deviated and formed a heat transfer fluid circulating which was advantageous for the products. Because of the recirculating, the temperature uniformity of two ceramics were slightly different.

3) The dispersion coefficient cvwas used for evaluation and the two main process control parameters that fuel inlet velocity and air-fuel ratio were simulated and optimized. The result showed that the temperature uniformity of the furnace was considered under the best condition either the injecting velocity of natural gas reached 4.5m/s or the natural gas, air inlet velocity ratio (air-fuel ratio) reached 3.21.

KEY WORDS: Roller kiln Temperature uniformity Plumbing fixture Numerical simulation

卫生洁具辊道窑烧成带温度均匀性仿真研究

目录

第1章 绪论 .............................................................. 1

1.1 陶瓷辊道窑国内外现状 ............................................. 1

1.1.1 辊道窑的发展现状 ........................................... 1 1.1.2 辊道窑的研究现状 ........................................... 2

1.2 研究目的及内容 .................................................. 3

1.2.1 研究目的 ................................................... 3 1.2.2 研究内容 ................................................... 4

第2章 卫生洁具辊道窑烧成带结构与运行原理 ............................... 5

2.1 辊道窑烧成带结构 ................................................. 6 2.2 辊道窑烧成带运行原理 ............................................. 7 第3章 辊道窑烧成带数学模型的建立 ....................................... 8

3.1 简化与假设 ....................................................... 8 3.2 物理模型 ......................................................... 9 3.3 数学模型和解析域 ................................................. 9

3.3.1 控制方程 .................................................. 10 3.3.2 湍流模型 .................................................. 10 3.3.3 燃烧模型选取 .............................................. 11 3.3.4 辐射传热模型选取 .......................................... 11 3.3.5 解析域分析 ................................................ 12 3.4 网格划分 ........................................................ 12 3.5 控制方程的离散化 ................................................ 13 3.6 计算方法及模型 .................................................. 14 3.7 章节小结 ........................................................ 14 第4章 辊道窑烧成带基准工况数值模拟 .................................... 15

4.1 边界条件和求解方法 .............................................. 15

4.1.1 选择边界类型 .............................................. 15 4.1.2 窑壁边界条件及物性参数 .................................... 15