低温烟气余热回收气液式热管式换热器设计分析毕业论文
2022-01-09 17:58:59
论文总字数:29068字
摘 要
现阶段,节能减排依旧是首要任务之一。在余热回收领域已经有大量的研究证明高温烟气余热已经可以被极好的利用。因此本文结合气液式热管对于低温烟气余热回收进行探索,希望有所助力。
本文首先通过对国内外作者的研究,对热管及余热回收做了一定程度的介绍,并对本文研究热管的理论进行阐述。通过热管传热极限以及翅化率翅化比理论设计出一套气液式热管,对设计结果参数运用固定参数法进行数据分析。
本文在设计的气液式热管换热器的基础上采用Excel建立换热器的设计模拟算法,进行可选参数影响分析。主要分析参数热管水侧水流速和水流量烟气侧翅片参数和热管管壁厚度和翅片高度。主要进行换热器的热力分析,管束的排布方式,换热器的结构设计与优化等。对低温烟气余热回收相关设计有一定的佐证与补充。
分析结果如下:1.热管设计时流体质量流量和流速共同制约热管长度。当改变工质流量及流速时传热面积随热管程度的更改而更改并且影响对流传热量,极大地影响传热效果。2.翅化比和对流传热受翅片参数的影响,但是在合理的设计要求下影响较小。其中影响力最大的是翅片间距。3.热管外径和壁厚是设计热管要考虑的首页因素,两者对传热的方方面面都有影响,热管外径还对管外流体流动阻力影响较大。
关键词:低温烟气 余热回收 热管式换热器
Design and Analysis of Gas-liquid Heat Pipe Heat Ex changer for Exhaust Gas recovery from Exhaust Gases at Low Temperature
ABSTRACT
In this phase, energy saving and emission reduction are still the top priority. A lot of research has been done in the area of waste heat recovery to prove that the high-temperature waste gas heat can already be used excellently.Therefore, this article combines gas-liquid heat pipes to explore low-temperature flue gas waste heat recovery, hoping to help.
First of all, this article explains the definition, meaning through research on authors at home and abroad, a certain degree of introduction to heat pipes and waste heat recovery, the theory of heat pipe research in this article.A set of gas-liquid heat pipes is designed through theory, and data analysis is performed on the design result parameters.
This article uses Excel based on the designed gas-liquid heat pipe heat ex changer to build the heat ex changer's design simulation algorithm and analyze the impact of optional parameters. The main analysis parameters are the water-side water flow rate of the heat pipe and the water flow exhaust gas-side l a m e l la parameters, the heat pipe wall thickness and the l a m e l la height. Mainly performs thermal analysis of heat ex changers, arrangement of tube bundles, structural design and optimization of heat ex changers etc. There is certain evidence and supplement to the design of low-temperature flue gas waste heat recovery.
The analysis results are as follows: 1. The fluid mass flow rate and flow velocity in the design of the heat pipe jointly restrict the length of the heat pipe. When the flow and flow rate of the working medium are changed, the heat transfer area changes with the change of the degree of the heat pipe and affects the convection heat transfer, which greatly affects the heat transfer effect.2. The fining ratio and convective heat transfer are affected by the fin parameters, but they are less affected by reasonable design requirements. The most influential one is the fin spacing.3. The outer diameter and wall thickness of the heat pipe are the first factors to be considered in the design of the heat pipe. Both have an impact on all aspects of heat transfer. The outer diameter of the heat pipe also has a great influence on the resistance to fluid flow outside the pipe.
Key Words: Low temperature flue gas;Waste heat recovery;Heat pipe heat ex changer
目 录
摘 要 I
ABSTRACT II
第一章 绪论 1
1.1 课题意义及研究背景 1
1.2 热管交换器的研究现状 1
1.2.1余热回收热管分类 1
1.2.2热管材料研究 2
1.2.3热管结构研究 3
1.2.4热管翅片参数研究 4
1.2.5热管存在的问题及防治措施 6
1.3 低温烟气余热回收的研究现状 7
1.4 本文研究内容 8
第二章 气液式热管换热器设计理论基础 9
2.1 烟气侧翅片管 9
2.2 两侧传热机理 9
2.2.1传热计算方程式 9
2.2.2重力式热管换热过程 10
2.3 翅片类型选取 11
2.4 翅化效率及翅化比 12
2.5 壳体设计 12
2.6 本章小结 13
第三章 热管换热器设计计算 14
3.1 设计参数 14
3.2 换热器热力计算 14
3.3 换热器结构计算 15
3.4 热阻计算 16
3.5 校核计算 17
3.6 本章小结 18
第四章 烟气侧与水侧数值分析 19
4.1 水侧管长对传热影响 19
4.1.1流体水流速影响分析 19
4.1.2流体水流量影响分析 20
4.2 烟气侧翅片参数影响分析 21
4.2.1翅片外径和翅片厚度影响分析 21
4.2.2翅片间距影响分析 22
4.2.3翅片高度影响分析 22
4.3 热管规格影响分析 23
4.3.1热管管壁厚度影响分析 23
4.3.2热管外径影响分析 24
4.4 优化结构设想 24
4.5 本章小结 25
第五章 结论与展望 26
5.1 研究结论 26
5.2 研究展望 26
参考文献 27
致 谢 31
第一章 绪论
1.1 课题的意义及研究背景
由于受到产业的结构、技术水平与经济规模等因素的制约在我国存在占社会总能耗十分之七以上的工业多余消耗能源,并且伴随着工业生产的过程将会产生工业余热资源。因此我国的综合能源消费量和煤炭消费量一直居高不下。我国与巴基斯坦友好外交,建设了吞吐量与上海接近的港口,降低引进资源的运输耗费。即使如此资源缺乏依旧是我们需要应对的问题。据统计可知工业余热资源约占其燃料总热量的20%左右到70%左右,而工业余热资源中的60%都可以回收,余热资源利用的空间任然充裕。
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