论文总字数：25663字

摘 要

随着中国近30多年的飞速发展，消耗了地球上的大量资源，而其中的大部分都是能源资源，比如石油、煤炭、天然气等短期内难以恢复的不可再生资源，所以能源问题将是长期影响中国发展的一个问题。而热管作为高效传热元件，因优越的传热性能和技术特性，在工程的应用日益普及，不仅在余热回收、节能方面取得了显著效果，而且在传统的传热传热传质设备更新改造及电子元器件冷却方面取得了显著效果。在科技迅速发展的今天，除湿能耗已经占到空气调节总能耗的20-40%。空气中的水蒸气含量虽然很少，但是由于水的汽化潜热比较高，

空气中的水凝结出来时会释放出客观的热量，利用热管可将这部分热量收集起来用来加热低温低湿的空气，可以改善除湿时能源的浪费问题，达到节能的目的。

本文利用流体计算软件Icepak,通过改变翅片间距、翅片厚度和热管间距，分析其对换热器的传热系数h、传热热阻R的影响。计算结束后，对模型的温度场、速度的矢量场、速度标量场以压力场进行分析。以了解传热与流动的情况。之后将处理的Re数、Nu数、传热系数h、传热热阻等数据与各变量参数整理为折线图，以定性分析其影响。

数值模拟的结果表明：随着迎面风速的增加，Nu数增加，传热系数显著的增加，传热热阻减小；随着翅片间距的增加，Nu数减小，传热系数减小，热阻增大；随着翅片厚度的增加，Nu数增大，传热系数增大，传热热阻减小；随着热管间距的增加，传热系数减小而传热热阻增大。本文数值模拟的结果可以为热管换热器的设计与试验提供参考。结合传热效率和经济性的原则选取翅片间距2mm，翅片厚度0.8mm,热管间距18mm，风速3m/s。通过设计计算，换热器热管总数为158根，叉排的排列方式，迎风横向管排数23排，纵向管排数7排。

关键词：除湿 仿真模拟 整体翅片热管 传热系数 热管换热器

Analysis on dehumidifying heat exchanger characteristics on forked arrangement of integrated finned tubes

ABSTRACT

With the rapid development of China over 30 years, it has consumed a large number of resources on the planet, and most of which are energy resources, ike the oil, coal, natural gas and the other non renewable resources, so the problem of energy will be a long-term impact on China's development. The heat pipe is the heat efficient element. Due to its superior heat transfer performance and technical character, it is widely used in the industry. It has achieved remarkable results in the heat transfer and energy saving, and it also has achieved remarkable results in the traditional heat and heat transfer equipment renewal and electron cooling.Now, with the society rapid development , the desiccant energy consumption has accounted for the total energy consumption of 20-40%.Although the content of water vapor in air is little, the latent heat of water vaporization is relatively high. When the water in the air condense, it will release remarkable heat quanlity.The heat pipe can collect the heat quanlity to heat the air of low temperatuer and humidity,which help to achieve the purpose of energy saving.

With changing one of the three variations, fin pitch, fin thickness and tube pitch, numerical simulation were performed with the help of the fluid calculation software, Icepak, to analyze the effects to the heat exchanger on the heat transfer coefficient, the heat transfer resistance and pressure drop. After the calculation, some distribution maps, such as temperature field, the velocity vector field, speed scalar field and the pressure field, were read to analyze the performs of the heat transfer and flow. After all the simulation was done, drafting the Re number, Nu number, heat transfer coefficient h and heat transfer resistance R with the variable parameters into line graph forms made it convenient to analyze the three specific factors' influencing trend on finned tube exchanger.

Numerical simulation results showed that heat transfer coefficient increased with the increase of head wind air velocity, while the thermal resistance of R decreased. With the increasing of fin pitch, the Nu number and flow resistance both experience a decreasing process. The heat transfer coefficient increased with the increase of fin thickness. With the increasing of tube fitch, heat transfer coefficient ascend, while the heat transfer resistance R go through a decreasing process. The result s will provide a reference to the design and experiment of the air cooler .Combined with the principle of heat transfer efficiency and economy, the fin spacing 2mm, fin thickness 0.8mm, heat pipe spacing 18mm, wind speed 3m/s.Through the design calculation, the total number of heat pipe for heat exchanger is 158, the row number of the transverse tube is 23 rows, and the longitudinal tube is row number 7.

Key words: dehumidification 、analogue simulation、integrated finned tube、heat transfer coefficient、heat exchanger

目录

摘要…………........……..…………………………………………………………...Ⅰ

ABSTRACT............….…………....……………………………………………...Ⅱ

符号表…………………......……......……………………………………......……..Ⅵ第一章 绪论…………......………….......…..……………………………………...1

1.1研究背景……………....….………...………………………………………......1

1.2热管换热器的应用…....….…………...………………………………………..1

1.2.1 热管换热器的应用现状….....………..…………………………………...2

1.2.2 热管换热器在除湿中的应用….....…..…………………………………...2

1.3 热管换热器在国内外的发展现状…....……..………………………………..2

1.3.1 热管换热器的国内研究综述….....……..………………………………...2

1.3.2 热管换热器的国外研究综述….....……..………………………………...4

1.4 热管换热器的传热分析………...…....……...……………………..................4

1.5 总结………………………..…………....……..................................................5

第二章 翅片管模型建立…………..….....……………………………...............6

2.1 ANSYS Icepak简介………………......…………………………………….....6

2.2 物理模型………………………........…..………………………………….....7

2.3 几何模型………………………..........…………………………………….....8

2.4 边界条件………………………..........…………………………………….....9

2.5 网格划分………………………….......…………………………………......10

第三章 数据处理及分析…………….....….......…………………..................13

3.1 对流传热问题完整的数学描述………..….....……………………………..13

3.2 理论计算………………………………..….....…………………………......13

3.3 模拟结果后处理……………………..…….....…………………………......15

3.4.1 相关定性参数的简化 ………….……....………………………….......15

3.4.2 计算所用参数的定义……………….…....………………………….....16

3.4 模拟结果与理论结果对比……………..….....…………………………......16

3.5 模拟结果云图分析………………………......……………..........................17

3.6 模拟数据汇总及分析……………………......………………......................26

第四章 热管换热器设计………………........…………………………….....32

4.1 整体型型翅片热管热器设计…………......…………………………….....32

4.1.1 设计步骤…………………………….....…............................................32

4.1.2 确定物性参数………………….....………………………………........32

4.2 计算传热量Q……………………......………….........................................32

4.3 冷空气出口温度t₂^C及对数平均温差_m…......…………………………33

4.4 确定迎风面积及迎风面管排数B………......…….…………………..34

4.5 求总传热系数 ………...........................…......………………………..35

4.6 求加热侧总传热面 .....................................................................................38

4.7 求所需热管数n............................................................................................38

4.8 求换热器纵深排数m...................................................................................38

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