叉排椭圆翅片管的传热与流动分析毕业论文
2022-07-13 22:03:45
论文总字数:26768字
摘 要
本文分为三个部分:首先,文章对翅片管式热交换器的定义、结构、国内外研究和发展现状进行综述。其次,本文通过理论计算设计了一台空气冷却器,以对其形成完整的全面的了解。最后,文中采用流体计算软件Icepak 对影响翅片管式换热器流动和传热性能的因素进行数值模拟分析。
计算结束后,本文先以基本模型为例对其温度场、速度矢量场、速度标量场以及压力场进行定性分析以了解整个翅片管式换热器的传热状况,从图中可以直观的看出换热强烈和换热薄弱以及流动剧烈和流动平稳的区域。然后文中将后处理的数、数、传热系数、范宁摩擦系数、传热热阻等数据与变量参数(迎面风速u,翅片间距,翅片长半轴,)整理成折线图的形式,以定性分析各因素的具体影响趋势。其中,选取不同迎面风速4m/s,5m/s,6m/s,7m/s,8m/s不同翅片间距6mm,7mm,8mm,9mm,10mm,不同翅片长轴47mm,49mm,51mm,53mm,55mm,计算结束后,本文先以基本模型为例对其温度场、速度矢量场、速度标量场以及压力场进行定性分析以了解整个翅片管式换热器的传热状况,从图中可以直观的看出换热强烈和换热薄弱以及流动剧烈和流动平稳的区域。然后文中将后处理的数、数、传热系数、范宁摩擦系数、传热热阻等数据与变量参数(翅片间距、翅片厚度,翅片长半轴,翅片短半轴)整理成折线图的形式,以定性分析各因素的具体影响趋势。
通过模拟计算并比较数据得出结果:随着迎面风速增大,数增大;随着翅片间距增大,数减小,摩擦系数减小,传热热阻减小。
关键词:椭圆翅片管 数值模拟 传热特性 流动特性
Analysis of flow and heat transfer in elliptical staggered fin tubes
Abstract
From the global view, the paper will be departed into three stages. Firstly, a roughly review of the definition, structure, domestic and foreign research and the current development conditions about finned tube heat exchanger was given. Secondly, in order to form a more comprehensive understanding of the heat exchanger, an air-cooler through traditional theoretical calculation methods was designed. Finally, the numerical simulation analysis was carried out about how the following factors(wind speed, fin spacing, fin long shaft ) impact the flow and heat transfer characteristics of finned tube heat exchanger with the fluid calculation software-Icepak.
And then, changing one of the five assumed factors (wind speed,fin spacing,,fin long half shaft) alone and collecting enough useful dates for some more analysis in detail helped to find the specific influence mechanism on the heat transfer coefficient, the fanning friction factor and the heat transfer resistance of finned tube heat exchanger. Additionally, in the actual simulation process, the wind speed was set to 4m/s,5m/s,6m/s,7m/s,8m/s,The factors were considered separately: fin Spacing(6mm,7mm,8mm,9mm,10mm),fin long shaft(47mm,49mm,51mm,53mm,55mm).On the one hand, the software Icepak could read some distribution map like the temperature field,the velocity vector field, the speed of scalar field and the pressure field from which the reader could easily discriminate the region where the heat transfer was strong and the area with enhanced flowing.On the other hand, drafting the number, number, heat transfer coefficient, the fanning friction factorand heat transfer resistance .
At last, after the numerical simulation and comparative analysis, the following results can be achieved: with the increasing of wind speed, thenumber, and number are both enhanced, while the fanning friction factorand the thermal resistance of decrease; with the increasing of fin spacing, thenumber and the fanning friction factor both experience a decreasing process, but the heat transfer resistance remains basically unchanged.
Keywords: elliptic tube fin;numerical simulation;heat transfer characteristic;flow characteristic
目录
第一章 绪论......................................................1
1.1 课题背景.................................................1
1.2 翅片管的类型和选择.....................................1
1.3 翅片管的构造和工作原理...............................1
1.4翅片管的应用与研究.....................................2
第二章 翅片管模型建立.........................................6
2.1 翅片管物理模型及介绍...................................6
2.2 翅片管几何模型..........................................8
2.3 典型翅片管换热器—空冷器设计.........................10
2.4 软件模拟结果与理论计算结果对比......................14
2.5 小结....................................................15
- 数值模型建立...........................................15
3.1 边界条件................................................15
3.2 数值参数设定及模型建立................................16
3.2.1 模型建立............................................16
3.2.2 网格划分............................................17
3.2.3 网格质量检查........................................17
3.2.4 网格划分展示........................................18
3.2.5 网格无关性检查......................................19
3.3 小结................................................... 20
第四章 数据处理及分析........................................23
4.1 传统理论计算方法................................... ..23
4.2 相关控制方程.......................................... 25
4.3 模拟结果后处理计算................................... 26
4.4 模拟结果云图分析......................................27
4.5 模拟数据汇总及分析..............................35
4.5.1 翅片间距对换热器流动和传热性能的影响...............35
4.5.2 翅片长轴对换热器流动和传热性能的影响...............37
4.6 小结....................................................39
第五章 结果与展望.............................................39
5.1 模拟结论...............................................39
5.2 未来展望...............................................39
致谢..............................................................41
参考文献.........................................................43
第一章 绪论
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