摘 要

现代工业中，板式换热器在各个领域都起着越来越重要的作用，科研人员的重要工作优化板式换热器的结构，这成为各个国家共同努力的研究方向。本篇文章主要研究的数据模型为极地船舶海水冷却系统人字形板式换热器，主要内容是对人字形板式换热器的结构与数据进行三维立体建模、非结构化网格划分、流体动力学软件FLUENT数值模拟仿真，最后进行数值化分析。以下为工作的三个方面：

首先，对国内外板式换热器的研究进行理性分析，找出拟解决的关键性问题及说明本文要研究的主要内容，还有对流体动力学计算方程进行简要介绍。

然后，对人字形波纹板式换热器建模，通过ICEM软件、Pro/Engineer或SOLIDWORKS等相关三维建模软件建立板片模型。再将所建三维板片模型导入到ICEM中划分网格。之后对FLUENT中人字形波纹板式换热器两相流换热进行特性仿真，在FLUENT中仿真两相海水-冰晶介质在人字形波纹板式换热器中与淡水换热，在流体动力学软件FLUENT中对人字形波纹板式换热器在给定的参数下（波纹倾角β、波纹深度h、波纹间距λ）进行模拟仿真分析，本次研究的是介质以海水-冰晶两相流为流动介质，判断板内是否有冰堵现象的发生（判断标准以板内冰晶流速v_ice=0m/s时有冰堵发生，当时v_icegt;0m/s冰堵现象不会出现）。

最后，对板式换热器的特性进行分析，根据FLUENT仿真在给定几何参数值下（波纹倾角β、波纹深度h、波纹间距λ）分析海水-冰晶换热大小，得到在给定参数值下的努塞尔数Nu数值，此次研究为极地船舶海水冷却系统的设计。

关键词：人字形板式换热器；数值模拟与仿真；计算流体动力学；换热性能；

Abstract

In modern industry, plate heat exchangers play an important role in various fields. How to optimize the structure of plate heat exchanger is a significant work for scientists , attracting experts from other countries to research together . Data model for at article main research vessel Polar Sea Water Cooling System chevron plate heat exchanger, the main content is a chevron plate heat exchanger structure and three-dimensional modeling data, unstructured meshing, hydrodynamic learning simulation software FLUENT numerical simulation. Finally, numerical analysis. These aspects would be mentioned as follow:

Firstly, making a analysis on the research for plate heat exchangers ,and then find what should be solved to explain the main content of this data. Meanwhile , a brief introduction about equations of fluid dynamics would be made.

Then, chevron corrugated plate heat exchanger modeling, sheet model established by ICEM software, Pro / Engineer or other related SOLIDWORKS 3D modeling software. Then built a three-dimensional sheet model into ICEM in mesh. After FLUENT human-shaped corrugated plate heat exchanger heat transfer in two-phase flow characteristics of simulation in FLUENT two phases seawater - in ice medium chevron corrugated plate heat exchangers and freshwater heat exchangers, fluid dynamics software FLUENT the chevron corrugation of the plate heat exchanger in the given parameters (corrugated inclination β, corrugation depth h, corrugated spacing λ) perform simulation analysis, this study is the medium sea - ice crystals two-phase flow of the flowing medium, determine whether there is an ice blocking phenomenon occurs (when the criteria in the inner plate ice velocity v_ice = 0m / s ice block occurs when the v_icegt; 0 m / s ice blocking phenomenon does not occur).

At last, we make a analysis on the characteristics of plate heat exchanger ,base on which we come to conclusion about (corrugated inclination β, corrugation depth h, corrugated spacing λ) sea - ice heat exchanger size to give efforts at a given parameter values Sergio number Nu value, In all, this data mainly introduces the design of seawater cooling system of polar ship.

Key Words: chevron plate heat exchanger; Numerical modeling and simulation; Computational fluid dynamics; Heat transfer performance;

目 录

第一章 绪论 1

1.1选题的目的与意义 1

1.2板式换热器研究现状 2

1.3拟解决关键问题 4

1.4研究内容 5

第二章 流体动力学基本方程 6

2.1引言 6

2.2流体动力学基本方程 6

2.2.1连续性方程 6

2.2.2能量方程 7

2.2.3动量方程 8

2.3热力学理论 8

2.3.1热力学第一定律 8

2.3.2热力学第二定律 9

2.3.3等熵理论 9

2.4流体动力学数值计算方法 11

2.5本章小结 15

第三章 板式换热器的建模与网格的划分 16

3.1引言 16

3.2三维软件建模与网格的划分 16

3.2.1人字形板式换热器建模 16

3.2.2人字形板式换热器的网格划分 17

3.3本章小结 21

第四章 人字型板式换热器的仿真与分析 22

4.1人字形波纹板板式换热器的数值模拟仿真 22

4.1.1FLUENT的优点 22

4.1.2计算流体动力学仿真 22

4.2数值仿真结果 24

4.3人字形板式换热器的分析 26

4.4本章小结 27

第五章 总结 28

5.1本文完成工作及创新点 28

5.1.1工作的完成状况 28

5.1.2创新点 28

5.2展望 29

参考文献 30

致 谢 32

第一章 绪论

1.1选题的目的与意义

极地运输船在极地低温环境下运行时^[1]，海水-冰晶常常进入海水冷却系统换热管道，为了使船舶辅机等设备减少受到高温的影响，避免堆积大量冰而导致换热器管路堵塞^[2]，从而造成船舶动力系统故障而失去控制，为确保其正常平稳的工作，必需要求合理地设置板式换热器的三个重要几何参数（波纹倾角β、波纹深度h、波纹间距λ）^[3-6]，如图1.1所示。