【作者】 黄明登；

【导师】 江乐新；

【作者基本信息】 中南大学 ， 机械工程， 2014， 硕士

【摘要】 在工业余热回收中,翅片管换热器作为设备的核心部件不可或缺,常用的圆翅式管换热器在一些多烟尘的中低温烟气余热回收中常常出现积灰、结垢问题,导致换热效率急剧下降。近几年出现的一种纵翅片换热器能有效解决翅片积灰、结垢问题,但因换热效果不是很理想而使用范围受到限制。本文在现有纵翅片换热管的基础上对纵翅片管翅片结构型式进行研究,分析不同纵翅片结构对阻力及传热性能的影响规律,并提出了一种高效实用的新型纵翅片结构型式,为设计用于烟气余热回收的纵翅片管换热器提供了有价值的参考。纵翅片换热器的核心结构是内部的纵翅片管,本文主要对纵翅片管的翅片结构进行结构改进研究,将常见的三种翅片型式设计思想应用于纵翅片管的翅片结构设计中,通过与现有平板纵翅片管进行阻力性能与传热性能的对比,找到最佳纵翅片结构型式,再对其进行结构参数优化。本文的主要内容有：首先,提出了错位翅、波纹翅、百叶窗翅三种新型纵翅片,分析了对比及优化的理论依据,建立了四种纵翅片的数值模型,采用数值模拟方法对比分析了三种新型纵翅片与平板纵翅片的阻力及传热性能。结果表明,百叶窗纵翅片管传热性能最优,综合性能最佳。其次,对百叶窗翅片管进一步研究,研究了百叶窗翅间距、倾斜角度及厚度三个主要结构参数对阻力及传热性能的影响规律,并分析了三者对百叶窗翅片管性能的敏感度情况。根据结构参数对纵翅片管的影响规律及敏感度进行结构参数最佳尺寸的选取,获得了百叶窗纵翅片换热管的最优结构尺寸。最后,将数值研究中获得的最佳尺寸下的百叶窗式新型纵翅片管与现有平板纵翅片管进行流动及传热特性的对比试验研究,搭建了试验平台,通过压降、温差、速度实测数据及能量损耗率四个方面进行对比,并将实验值与模拟值对比,实验证明模拟结果基本可靠。图54幅,表5个,参考文献65篇。更多还原

【Abstract】 :In the project of recovery of waste heat,finned tubular radiator is a core component.Common round fin tube heat exchanger often arises scaling and fouling problem in low or middle exhaust gas temperature waste heat recovery, resulting in a sharp decline in heat transfer efficiency. In recent years, the emergence of a longitudinal fin heat exchanger can effectively solve the fouling problem, but poor heat transfer leads to limited scope. Based on the existing longitudinal fin heat exchanger,the paper aims at the study of various types of longitudinal fin tube,including improving it’s structure and parameter optimization.Also the paper presents a new efficient and practical longitudinal fin structure type, providing a valuable reference for the design of longitudinal fin tube heat exchanger in the project of gas waste heat recovery.The core structure of vertical fin heat exchanger is inner finned tubes.This paper mainly focuses on the structure proving. In this paper,the design ideas of three common finned forms are applied to the structure of longitudinal finned tube. Through the comparison of resistance and heat transfer characteristic on existing flat plate longitudinal finned tube,finding out the best form of longitudinal fin structure, then optimizing its structural parameters.The main contents of this paper are as follows.First, the method of numerical simulation research is used in a comparative study of resistance and heat transfer characteristic of four types of longitudinal fin tube, including dislocation fin, corrugated fin, louver fin and existing flat fin.The results show that the louver fin tube performs much better not only in the heat transfer effect but also in the comprehensive performance.Secondly, further research of louver fin tube is presented, which means the fluence of three main structural parameters on resistance and heat transfer characteristic, including spacing, tilt angle and the thickness of louver fin. And it also analysis the sensitivity case of three structural parameters of the louver fin tube in the performance.Finally, a contrast experiment of resistance and heat transfer characteristic study is made between the new longitudinal louvered fin tube and the existing flat longitudinal fin tube. The structural parameters of new longitudinal louvered fin tube is the optimal size found though numerical simulation research. A test platform is built.Press drop, temperature, velocity and energy loss rate are compared between the experimental and simulated experimental results.更多还原