USST_Arts_112320152管壳式换热器管束动力特性分析及流体诱导振动研究

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众所周知,换热器是将热流体的部分热量传递给冷流体的设备,是传热工程
中必不可少的设备,几乎一切工业领域都要使用,在化工、冶金、动力、航空与
航天等部门应用尤为广泛。在各类换热器中,间壁式换热器中的管壳式换热器由
于结构简单,操作可靠,可用各种结构材料制造,能在高温、高压下使用,应用
范围广泛,占整个换热设备使用总数的 70%左右。近几年来,随着工业的快速发
展,为改善传热性能,减少结垢堵塞,管壳式换热器趋向于大型化、高流量发展,
换热器中管束的无支撑跨度增大,刚性变差,由流体诱导振动产生的换热器振动
破坏事件也逐渐增加,流体诱导振动问题逐渐成为了阻碍换热器发展的重要因素。
本文将对管壳式换热器的管束动力特性和流体诱导振动进行研究,主要的工作和
结论包括:
1.采用数值模拟的方法对管壳式换热器进行流固耦合状态下的模态分析,计算
其实际工况下的固有频率,按照相关标准(GB151,对其进行管束振动分析。
2.采用数值模拟的方法对换热器管束进行流固耦合状态下的模态分析。分别建
立包含壳程流体的单根换热管,相同节径比、不同排列方式的四根换热管,相同
排列方式、不同节径比的三根以及七根换热管模型。计算其实际工况下的固有频
率,研究不同排列方式与不同节径比对于换热器管束在其实际工况中的固有频率
的影响。
3.采用计算流体力学计算软件对换热器壳程流体进行流场分析。根据换热器实
际工况,分别建立不同节径比的三根以及七根换热管圆柱绕流模型,研究不同节
径比对于换热器壳程流场的影响。
本文的研究成果有助于理解管壳式换热器管束动力特性及壳程流体的流动情
况。在工程实际中,对换热器的防振设计有很好的参考价值。
关键词:换热器 动力特性 数值模拟 诱导振
ABSTRACT
It is known that Heat Exchanger is an necessary equipment in the thermal
transmission which transfer heat from hot fluid to cool fluid, used in most industry
fields especially in the Chemical Industry Metallurgy Industry, Dynamic Industry
and Aerospace Industry. Among different kinds of Heat Exchangers, the Shell-and
Tube Heat Exchanger occupy almost 70% consumptions for its simple structure, reliable
operation, manufactured in different kinds of materials, used under high temperature
and pressure. Recently, with the fast development of industry, Shell-and Tube Heat
Exchangers are developing into the large-scale and high-flow style so as to improve the
heat exchanger efficiency. So the non-support span increases which makes the tubes
rigidity poorer. Meanwhile, the flow-induced vibration becomes the focus for the
accidents caused by the flow-induced vibration increased, as well. This dissertation
takes the dynamic characteristic and flow-induced vibration of the Heat Exchanger as
the research object. The main study and conclusions are as follows:
1.Numerical simulation is used here to analyze the modal of the Shell-and-Tube
Heat Exchanger under the fluid structure interaction. Natural frequency of Exchanger is
calculated under the real condition, and the vibration analysis is done according to the
relative standard(GB151);
2.Numerical simulation is used here to analyze the modal of the Tube Bundles
under the fluid structure interaction. Single tube model, four tubes model with the same
pitch diameter ratio and different arrangements, three and seven tubes model with the
same arrangement and different pitch diameter ratio are made separately to calculate
their natural frequencies and study the influence of different arrangements and pitch
diameter ratio in their natural frequencies under the real condition;
3.Computational fluid dynamics software is used here to analyze the fluid field of
the exchanger. Three and seven tubes under the flow around a circular cylinder with
different pitch diameter ratio are established separately under the real condition to study
the influence of different pitch diameter ratio on the fluid field of shell side.
The research of this dissertation is helpful to understand the dynamic characteristic
of the Shell-and-Tube Heat Exchanger and its flow condition of the shell side, and good
reference value to the shockproof design of Heat Exchanger in the practical engineering.
Key WordsHeat Exchanger, Dynamic Characteristic, Numerical
Simulation, Flow-induced Vibration
中文摘要
ABSTRACT
第一章 ........................................................ 1
1.1 研究背景 ........................................................ 1
1.2 流体诱导振动的研究进展 .......................................... 4
1.2.1 漩涡脱落的研究进展 ......................................... 4
1.2.2 流体弹性不稳定的研究进展 ................................... 5
1.2.3 换热器管束动态特性的研究进展 ............................... 6
1.2.4 相关标准规范简介 ........................................... 6
1.3 研究内容和目的 .................................................. 6
第二章 流体诱导振动 ................................................. 8
2.1 引言 ............................................................ 8
2.2 振动 ............................................................ 9
2.3 管束振动特性 .................................................... 9
2.3.1 直管的固有频率 ............................................. 9
2.3.1.1 管子与挡板孔余隙 ........................................ 10
2.3.1.2 轴向应力 ................................................ 10
2.3.1.3 间距长度 ................................................ 10
2.3.1.4 管子振动的振幅 .......................................... 11
2.3.1.4 系统阻尼 ................................................ 11
2.4 换热器的壳侧流速 ............................................... 12
2.4.1 交叉流速度 ................................................ 12
2.4.2 平行流速度 ................................................ 12
2.4.3 泄漏和旁路流速度 .......................................... 12
2.4.4 流体进出口速度 ............................................ 13
2.4.5 旋转速度 .................................................. 13
2.5 流体诱导振动现象 ............................................... 13
2.5.1 漩涡脱落 .................................................. 13
2.5.2 湍流抖振 .................................................. 14
2.5.3 流体弹性不稳定 ............................................ 14
2.5.4 平行流涡流的形成 .......................................... 15
2.5.5 声振 ...................................................... 15
2.5.5 复合现象 .................................................. 16
第三章 管壳式换热器的数值模拟分析 .................................. 17
3.1 算例说明 ....................................................... 17
3.2 换热器动态特性分析 ............................................. 19
3.2.1 有限元方法简介 ............................................ 19
3.2.2 换热器固有频率求解原理 .................................... 19
3.2.3 单元介绍 .................................................. 20
3.2.4 模型介绍 .................................................. 22
3.2.5 模型建立,边界条件施加 .................................... 22
3.2.6 计算结果 .................................................. 24
3.2.7 卡门涡街频率 .............................................. 25
3.2.8 结论 ...................................................... 26
第四章 换热器管束动力特性研究 ...................................... 27
4.1 引言 ........................................................... 27
4.2 模态分析的定义及其应用 ......................................... 27
4.3 换热管的模态分析 ............................................... 27
4.3.1 单根换热管模态分析 ........................................ 28
4.3.2 管束不同排列方式对固有频率的影响 .......................... 37
4.3.2.1 四根换热管等边三角形排列模态分析 ........................ 38
4.3.2.2 四根换热管正方形排列模态分析 ............................ 44
4.3.2.1 小结 .................................................... 51
4.3.3 三根换热管不同节径比对固有频率的影响 ...................... 51
4.3.3.1 节径比为 1.28 的三根换热管模态分析 ....................... 51
4.3.3.2 节径比为 1.4 的三根换热管模态分析 ........................ 57
4.3.3.3 节径比为 1.5 的三根换热管模态分析 ........................ 58
4.3.3.4 节径比为 1.6 的三根换热管模态分析 ........................ 59
4.3.3.5 节径比为 1.7 的三根换热管模态分析 ........................ 59
4.3.3.6 小结 .................................................... 60
4.3.4 七根换热管不同节径比对固有频率的影响 ...................... 61
4.3.4.1 节径比为 1.28 的七根换热管模态分析 ....................... 61
4.3.4.2 节径比为 1.4 的七根换热管模态分析 ........................ 71
4.3.4.3 节径比为 1.5 的七根换热管模态分析 ........................ 71
4.3.4.4 节径比为 1.6 的七根换热管模态分析 ........................ 72
4.3.4.5 节径比为 1.7 的七根换热管模态分析 ........................ 73
4.3.4.6 小结 .................................................... 74
4.3.5 节径比对于频率带宽的影响 .................................. 75
4.4 总结 ........................................................... 76
第五章 换热器流场分析 .............................................. 78
5.1 引言 ........................................................... 78
5.2 计算流体力学 ................................................... 79
5.2.1 计算流体力学基本原理 ...................................... 79
5.2.2 CFX 简介 .................................................. 79
5.3 流场分析 ....................................................... 79
5.3.1 单管绕流 .................................................. 80
5.3.2 三管绕流 .................................................. 83
5.3.2.1 节径比为 1.28 的三管绕流 ................................. 83
5.3.2.2 节径比为 1.4 的三管绕流 .................................. 87
5.3.2.3 节径比为 1.5 的三管绕流 .................................. 89
5.3.2.4 节径比为 1.6 的三管绕流 .................................. 90
5.3.2.5 节径比为 1.7 的三管绕流 .................................. 92
5.3.2.6 小结 .................................................... 94
5.3.3 七管绕流数值模拟及分析 .................................... 94
5.3.3.1 节径比为 1.28 的七管绕流 ................................. 94
5.3.3.2 节径比为 1.4 的七管绕流 .................................. 98
5.3.3.3 节径比为 1.5 的七管绕流 ................................. 100
5.3.3.4 节径比为 1.6 的七管绕流 ................................. 102
5.3.3.5 节径比为 1.7 的七管绕流 ................................. 103
5.3.3.6 小结 ................................................... 105
5.4 总结 .......................................................... 105
第六章 结论与展望 ................................................. 107
6.1 总结 .......................................................... 107
6.2 展望 .......................................................... 108
参考文献 .......................................................... 109
在读期间公开发表的论文和承担科研项目及取得成果 .................... 114
.......................................................... 115
USST_Arts_112320152管壳式换热器管束动力特性分析及流体诱导振动研究.pdf

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作者:牛悦 分类:高等教育资料 价格:15积分 属性:119 页 大小:9.07MB 格式:PDF 时间:2025-01-09

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