弹簧支撑管壳式换热器流动换热及诱导振动特性研究

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3.0 赵德峰 2025-01-09 6 4 3.57MB 67 页 15积分

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摘要

纵流程管壳式换热器是近些年来管壳式换热器研究的一种重要方向，相较于

弓形折流板管壳式换热器管、壳侧流体横向流动的特性，纵流程换热器可实现管、

壳侧流体全逆流流动，有效地消除传热死区，降低压降，这就意味着可用体积较

小的换热器达到同样的热负荷，降低运行费用。另外，这种换热器在防止诱导振

动方面也有非常优秀的表现。因此吸引了国内外众多研究投入到对其的研究中，

本文绪论中作了详细介绍。本课题涉及的弹簧支撑管壳式换热器是一种新型的纵

流程管壳式换热器，它采用弹簧代替折流板作为管束的支撑结构，同时又可起到

强化换热的目的。

本文首先建立起弹簧支撑管壳式换热器数学物理模型。对换热器物理模型进

行了若干简化处理：根据流体在换热器中流动特性，把研究对象简化为弹簧支撑

管壳式换热器的一个单元流道；计算流道当量直径时考虑了弹簧结构的影响等；

使用 ICEM 划分单元流道网格，对于不同的表面，采用不同的网格尺寸，在不影

响计算结果的前提下，降低对计算资源的要求。在网格划分完毕后，对弹簧支撑

弹簧支撑管壳式换热器的流动和换热特性进行了研究：分析了弹簧前后间距、弹

簧螺距、弹簧支撑长度对壳侧对流换热系数和压降的影响，比较了弹簧支撑和折

流板支撑下换热器的综合性能的优劣；运用多元线性回归拟合出了弹簧支撑管壳

式换热器努赛尔数 Nu 和阻力系数 f的关联式。

然后运用遗传算法，借助 MATLAB 软件对弹簧支撑管壳式换热器进行优化设

计，以投资运行的总费用为目标函数，弹簧前后间距、弹簧螺距、弹簧支撑长度，

壳侧直径为变量，经过编程，最终得出了给定换热量下弹簧支撑管壳式换热器的

结构参数。

最后，建立四组换热器管束的三维模型，研究其在不同弹簧前后间距、不同

弹簧螺距、不同弹簧支撑长度、不同弹簧组组数情况下诱导振动情况进行了分析，

主要是借助 ANSYS 软件的模态分析模块进行换热管束的模态分析即固有频率和

振型的分析；简单介绍了管束振动的数学模型，模态分析方法等内容；结合前人

研究成果和本课题的数据，提出防止弹簧支撑管壳式换热器诱导振动的若干措施。

关键词：弹簧支撑场协同强化传热优化设计诱导振动

ABSTRACT

Longitudinal flow heat exchanger has become an important research branch of

tube-and-shell heat exchanger in recent years. Compared to segmental baffle

tube-and-shell heat exchanger’s cross flow characteristic between shell side and tube

side, longitudinal flow heat exchanger can achieve an totally counter-flow between the

two different fluids, thus it avoid the heat transfer ‘Dead Space’ and reduce the pressure

drop, it means we can use a smaller heat exchanger to meet the same heat load

requirement and thus decreases the operation cost. Additionally, heat exchanger of this

kind has excellent performance in avoiding induced vibration. For the advantages

mentioned above, more and more researchers at home and abroad begin to do the

related subjects in this field, this has been described in preface in detail. The

tube-and-shell heat exchanger supported by springs involved in this paper is a new

Longitudinal flow heat exchanger type, it uses groups of springs rather than segmental

baffles to support the tubes and at the same time, enhances the heat transfer process.

Firstly, the mathematic and physical models of tube-and-shell heat exchanger

supported by springs are established. Here by several means simplifies the physical

model: According to the flow characteristics of fluid in the heat exchanger, an unit flow

channel is taken as the research objective, the influence of spring structure parameter is

taken into consideration when the calculation result data is dealt with and so on. Use

ICEM to draw the non-construction grid of the unit channel, different faces have

different grid parameter definition, thus it guarantees that the lowest computation

resource is needed in the premise that the calculation result is right. After drawing the

grid, the flow and heat transfer characteristics of tube-and-shell heat exchanger

supported by springs is researched. The subject analyses the variation of spring group

pitch, spring screw pitch, spring length’s influence to convective heat transfer

coefficient and pressure drop, next compare the comprehensive performance between

the segmental tube-and-shell heat exchanger and the tube-and-shell heat exchanger

supported by springs ;use multiple linear regression fit the Nu and f equation.

Next, An optimization calculation is carried out using the genetic algorithm by

MATLAB. In the chapter, the total investment and operation cost is taken as the

objective function, variables are shell diameter, spring group pitch, spring screw pitch

and spring length. Through programming, the optimal heat exchanger parameter under a

certain thermal load is obtained.

At last, establish the three dimension heat exchanger model, give the induced

vibration research of a heat transfer tube bundle in different spring group pitch, spring

screw pitch，spring length and spring group number. The major work is to analyze the

heat transfer bundle’s modal analysis characteristics, namely, natural frequency and

vibrational modes. Give a general vibration mathematic model and modal analysis

method and so on. Combining with former research result and data in this subject,

propose several measures to prevent the induced vibration of tube-and-shell heat

exchanger supported by springs.

Key Word: supported by springs, field synergy, heat transfer

enhancement, induced vibration

中文摘要

ABSTRACT

第一章绪论 .................................................................................................................... 1

1.1 前言 ........................................................................................................................ 1

1.2 纵流壳程换热器的研究现状 ................................................................................ 2

1.2.1 空心环 ............................................................................................................. 2

1.2.2 折流杆 ............................................................................................................. 3

1.2.3 螺旋折流板 ..................................................................................................... 3

1.2.4 整圆形板 ......................................................................................................... 5

1.2.5 螺旋扭片 ......................................................................................................... 6

1.2.6 管束自支撑 ..................................................................................................... 6

1.3 换热器优化设计研究现状 .................................................................................... 7

1.4 换热器诱导振动研究现状 .................................................................................... 8

1.5 本课题拟完成的工作 .......................................................................................... 10

第二章弹簧支撑管壳式换热器的数学物理模型 ....................................................... 11

2.1 物理模型的简化及相关假设 ............................................................................... 11

2.2 数学模型 ............................................................................................................... 12

2.3 湍流模型 ............................................................................................................... 13

2.4 边界条件 ............................................................................................................... 14

2.5 几何模型 ............................................................................................................... 14

2.6 模型的网格划分 ................................................................................................... 15

2.7 SOLVER 设置 ....................................................................................................... 16

2.8 当量直径的处理 ................................................................................................... 17

2.9 参数定义 ............................................................................................................... 18

2.10 本章小结 ............................................................................................................. 19

第三章弹簧支撑管壳式换热器流动与传热研究 ...................................................... 20

3.1 流场及温度场分析 .............................................................................................. 20

3.1.1 速度场分布 ................................................................................................... 20

3.1.2 温度分布 ....................................................................................................... 21

3.1.3 场协同分析 ................................................................................................... 22

3.2 弹簧前后间距变化 .............................................................................................. 24

3.3 弹簧螺距变化 ...................................................................................................... 26

3.4 弹簧长度变化 ...................................................................................................... 27

3.5 回归分析 .............................................................................................................. 28

3.5.1 回归介绍 ....................................................................................................... 28

3.5.2 关联式的拟合 ............................................................................................... 31

3.6 性能评价指标比较 .............................................................................................. 32

3.7 本章小结 ............................................................................................................... 34

第四章弹簧支撑管壳式换热器的优化设计 .............................................................. 36

4.1 遗传算法 .............................................................................................................. 36

4.2 数学模型的建立 .................................................................................................. 38

4.2.1 传热计算 ....................................................................................................... 38

4.2.2 压降计算 ....................................................................................................... 40

4.2.3 目标函数 ....................................................................................................... 40

4.3 优化计算 .............................................................................................................. 41

4.4 本章小结 .............................................................................................................. 42

第五章换热器管束诱导振动分析 .............................................................................. 44

5.1 管子的振动方程 .................................................................................................. 44

5.1.1 振动方程 ....................................................................................................... 44

5.1.2 方程的解 ....................................................................................................... 45

5.2 模态分析 .............................................................................................................. 46

5.3 ANSYS MODAL 介绍 ......................................................................................... 46

5.4 振动分析的物理模型及边界条件设置 ............................................................... 48

5.5 振动结果分析 ...................................................................................................... 48

5.5.1 弹簧长度变化 ............................................................................................... 48

5.5.2 弹簧螺距变化 ............................................................................................... 49

5.5.3 弹簧组前后间距变化 .................................................................................... 49

5.5.4 弹簧组数变化 ............................................................................................... 51

5.6 防止诱导振动的措施 .......................................................................................... 53

5.7 本章小结 ............................................................................................................... 53

第六章结论 ............................................................................................................ 55

6.1 主要结论 .............................................................................................................. 55

6.2 课题总结 .............................................................................................................. 56

6.2.1 课题的不足之处 ........................................................................................... 56

6.2.2 特色之处 ........................................................................................................ 56

符号 ................................................................................................................................ 57

参考文献 ........................................................................................................................ 58

在读期间公开发表论文和承担的科研项目及取得成果 ............................................ 62

致谢 ................................................................................................................................ 63

第一章绪论

1.1 前言

近年来，随着节能减排和环境保护的呼声越来越高，各国纷纷采取节能措施，

大力发展节能技术，燃料消耗指标不断下降。就我国而言，虽然在节能降耗取得

了一定的成绩，但能源短缺一直困扰国民经济持续、快速发展的难题。这其中一

个重要的原因就是能源浪费现象严重，我国能源的利用率只有 28%左右，还不到

日本的一半（约 57%），比西欧的 40%也低得多。因此，在节约能源方面，我国有

较大的潜力[1]。

换热器是化工、炼油、动力、食品、原子能、航空等许多部门广泛使用的一

种用于能量交换的工艺设备，在工厂建设投资中占很大比例：在火电厂中，如把

锅炉也作为换热设备，则换热器约占电厂总投资的 70%；在一般的石油化工企业

中，换热器的投资约占电厂总投资的 40%～50%；在现代石油化工企业中，约占

30%～40%；在一般的制冷机中，蒸发器的金属消耗量约占金属消耗总量的 30%～

40%。因此，换热器的合适设计和良好运行对企业节约资金、能源和空间起着至关

重要的作用。提高换热器的性能并减小其体积，在能源日趋短缺的今天更具有经

济效益和社会效益[2]。

在所有的换热设备中，应用的最多的是管壳式换热器，其结构可靠、技术成

熟，适用范围广，在多年的工程应用中已积累了丰富的设计和运行经验。但是传

统管壳式换热器采用折流板支撑管束，流体横向冲刷管束，在管束后和流体流向

改变的地方会产生传热死区，整个换热器流体耗费泵或风机的耗功较大，在高雷

诺数是还会产生诱发振动导致换热器失效[3,4,5]。为了解决这些问题。纵流壳程换热

器应运而生。

纵流式管壳式换热器[6]的主要特点是：

1）与错流式的折流板换热器相比，纵向流换热器具有非常低的压降和非常高

的“热传递-压降”比率，因为纵向流动时管束中的流体的摩擦压损仅发生在热传递

表面的管长上，正如流体在管内流动时那样，它没有像错流管束流过绕过弓形缺

口区域时较大的压力损耗。当壳程管束进出口处设置外导流筒时，其进出口段 L

（L取壳体直径Ds的值）压降，比通常横向冲刷进出口段时要小 5倍，且只占总压

降的 10%。

2）在整个换热管束上采用了折流杆或扁钢条格栅，或是整圆式孔板等结构来

支撑，可有效地防止管子的下垂和流体振动。尽管流体在纵向流过这些折流结构

时会产生流体的收缩和扩张的压力损失（对于折流栅结构，其值比管内摩擦因子

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