板式换热器设计.docx

本 科 毕 业 设 计 论 文

题 目 板式换热器设计

西安交通大学城市学院
本科毕业设计（论文）任务书
题 目

姓 名

1.毕业设计（论文）课题的主要任务：

（1）设计的主要任务
换热器在节能、能量转换，能量回收，以及新能源利用领域里的重要性日益增加。换热器也是工业和科研中广泛应用的换热设备之一，其设计过程要利用到传热学和流体力学的知识。
板式换热器是由一系列具有一定波纹形状的金属片叠装而成的一种新型高效换热器。板式换热器通常由薄板组装而成。种类繁多，如：密封式、焊接式、螺旋板式、板壳式等。该课题要求首先对各种换热器进行比较，然后选择一种结构合理、经济耐用的换热器，完成相关的设计、计算，最后画出装配图。通过与工程密切联系的课题研究，培养学生将实际知识利用于工程实践的能力。
（2）设计的主要目的
培养学生综合运用课程及有关选修课程基础理论和基本知识去完成板式换热器的设计任务的实践能力
（3）设计目标
设计的设备必须在技术上是可行的，经济上是合理的，环境上是友好的。
（4）设计条件
①处理能力：52t/h热污水
②设备型式：板式换热器
③操作条件：
热污水：入口温度90℃，出口温度35℃
冷却介质：自来水，入口温度25℃，出口温度70℃
容许压强降：不大于1MPa
每年按330天计，每天24小时连续运行
2.课题的具体工作内容（原始数据、技术要求、工作要求）：

（1）查阅相关文献资料，了解换热器的设计基本方法；
（2）对板式换热器的各种类型进行比较，然后选择一种结构合理、经济耐用的换热器，作为研究对象；
（3）根据板式换热器的特点，完成相关的设计计算，流道的选择等，写出设计过程；
A .计算总传热系数
B .计算传热面积
（4）换热器核算
（5）完成板式换热器的设计全过程；
（6）画出板式换热器的零件图；
（7）画出板式换热器的总装配图；
3.课题完成后提交的书面材料要求（论文字数，图纸规格、数量，实物样品，外文翻译字数等）：

（1）撰写出1.5万字以上的论文；
（2）零件图；
（3）装配图一张；
（4）不少于20，000印刷符号的英文翻译。
4.主要参考文献：

（1）王毅．过程装备测试技术[M]．北京：北京大学出版社，2010
（2）马履中．机械原理与设计．北京：机械工业出版社，2009
（3）余建祖编著．换热器原理与设计．北京航空航天大学出版社，2006
（4）沙拉、赛库里克著．程林译．换热器设计技术．北京，机械工业出版社，2010
（5）兰州石油机械研究所．板式换热器人字形波纹板片试验总结报告[J]，1972
（6）钱颂文等．换热器设计手册[M]．北京：化学工业出版社，2002
（7）杨崇麟．板式换热器工程设计手册[M]．北京：机械工业出版社，1995
（8）Flavio C.C, Galeazzo, Rsquel Y.Miura, et al. Ex-perimental and numerical heat transfer in a plate heat exchanger. Chemical Engineering Science, 2006, (61):7133-7138
（9）常春梅．国内可拆卸板式换热器现状及发展趋势．石油化工设备．2008，9（37，5）
（10）赵晓文，苏俊林．板式换热器的研究现状及进展．冶金能源．2011，1
（11）张晓锋．浅谈板式换热器．科技情报开发与经济．2009，10
（12）邹同华，杜建通．板式换热器设计选型及使用中应注意的问题．设计与安装
（13）李永新，杨峰，陈文强．板式换热器失效原因分析及维修方法．工业·生产．2006，4
要求完成日期： 年 月 日
指导教师（签名）：
接受任务日期： 年 月 日
学生（签名）：
系审批意见：

负责人签字：
年 月 日

摘 要

本设计是以板式换热器为设计对象，主要介绍了板式换热器传热原理。板式换热器是一种高效节能型换热设备,具有传热效率高 ,质量轻 ,占地面积小 ,易于维修等诸多优点。板式换热器的设计主要包括传热设计和框架结构设计。传热设计主要是根据介质和工况条件确定版式换热器的型号及板片的型号和介质的流动方式，而确定板片的型号关键是总传热系数K值的计算；框架结构设计是根据介质的性质、板片的尺寸和有关资料设计固定压紧板，活动压紧板，上、下导杆，夹紧螺柱等零部件的尺寸和材料，并根据有关标准规定校核各零部件的强度、稳定性。

关键词：板式换热器，总传热系数K，压紧板
ABSTRACT
This design is detachable plate heat exchanger for design object, mainly introduced the principle of heat, heat exchanger can disassemble phe is an efficient energy-saving heat exchange equipment, with heat transfer efficiency, light quality, cover an area of an area small, easy maintenance, and many other advantages. The heat exchanger design mainly includes the design and structure design of heat. Heat is designed according to the media and the conditions of heat exchanger model and determine the format and medium plate type, and determine the flow is the key of the plate type heat transfer coefficient of total K value calculation, Frame structure is designed according to the properties of medium, the size of the plate and the relevant material design pressure plate fixation, activities, and pressure plate under the guide bar clamping luozhu, etc, the size of the parts and materials, and according to the relevant standards of parts of checking intensity and stability.
KEY WORDS：The total heat transfer coefficient of plate heat exchanger, pressureplate

目录

摘 要 I
ABSTRACT II
1 绪论 1
1.1 板式换热器简介 1
1.2 板式换热器的基本结构 1
1.3 平板式换热器的特点 2
1.4 板式换热器的应用场合 3
1.5 板式换热器选型时应注意的问题 4
1.5.1 板型选择 4
1.5.2 流程和流道的选择 4
1.5.3 压降校核 5
1.6 结构原理 5
2 板式换热器国内外研究（设计）概况及发展趋势 7
2.1 应用前景 7
2.2 研究状况 7
2.3 发势展趋 8
3 板式换热器的设计 9
3.1 提高传热效率 9
3.11 提高板片的表面传热系数 9
3.12 减小污垢层热阻 9
3.1.3 选用导热率高的板片 9
3.1.4 减小板片厚度 9
3.2 提高对数平均温差 10
3.3 进出口管位置的确定 10
3.4 降低换热器阻力的方法 10
3.4.1 采用热混合板 10
3.4.2 采用非对称型板式换热器 10
3.4.3 采用多流程组合 11
3.4.4 设换热器旁通管 11
3.4.5 板式换热器形式的选择 11
3.5 橡胶密封垫材质及安装方式 11
3.5.1 材质的选择 11
3.5.2 安装方式的选择 11
3.5.3 合理选用板片材质 12
4 传热工艺计算 13
4.1 设计条件 13
4.2 符号 13
4.3 已知参数 14
4.4 板片的选取 14
4.4.1 总热负荷的计算 14
4.4.2 板片的选取 15
4.5 总传热系数K的计算 16
4.5.1 裕量要求 16
4.5.2 BR0.3的主要几何参数及相关关联式 16
4.5.3 K值的计算 17
5 板式换热器结构设计及强度校核 23
5.1 符号 23
5.2 已知参数 24
5.3 结构设计及强度校核 25
5.3.1 板片 25
5.3.2 压紧板设计及强度校核 25
5.3.3 夹紧螺柱设计及强度校核 28
5.3.4 导杆设计及强度校核 29
5.4 垫片 31
5.5 支柱设计及强度校核 32
5.6 开孔补强 33
5.6.1 补强及补强方法判别 33
结 论 35
参考文献 36
DESIGN OF HEAT EXCHANGER FOR HEAT RECOVERY IN CHP SYSTEMS 37

1 绪论
1.1 板式换热器简介
1.2 板式换热器的基本结构
1.3 平板式换热器的特点
板式换热器是将板片以叠加的形式装在固定压紧板、活动压紧板中间，然后用夹紧螺栓夹紧而成（见图1-1）。

1.4 板式换热器的应用场合
1.5 板式换热器选型时应注意的问题
1.6 结构原理

2 板式换热器国内外研究（设计）概况及发展趋势
2.1 应用前景
2.2 研究状况
2.3 发势展趋

3.1 提高传热效率
3.2 提高对数平均温差
3.3 进出口管位置的确定
3.4 降低换热器阻力的方法

3.5 橡胶密封垫材质及安装方式

4 传热工艺计算
4.1 设计条件
4.2 符号
4.3 已知参数
4.4 板片的选取

温度
t
(℃)
密度
ρ
(kg/m3)
比热容
cp
(kJ/(kg·K))
导热系数
λ
(W/(m·K))
动力粘度
μ×10－6
(Pa·s)
运动粘度
υ×10－6
(m2/s)
40
50
60
70
992.2
988.1
983.2
977.8
4.174
4.174
4.178
4.178
0.634
0.648
0.659
0.668
689.476
582.685
474.951
354.823
0.656
0.574
0.469
0.382

温度
t
(℃)
密度
ρ
(kg/m3)
比热容
cp
(kJ/(kg·K))
导热系数
λ
(W/(m·K))
动力粘度
μ×10－6
(Pa·s)
运动粘度
υ×10－6
(m2/s)
62.5
47.5
981.8
989.1
4.178
4.174
0.662
0.644
419.1
616.8
0.409
0.618

4.5 总传热系数K的计算

名称
波纹形式
单位
实测参数
人字形128°
板片厚度
波纹深度
波纹法向节距
板间距
当量直径
单片有效传热面积
单流道截面积
板片材料
板片外形尺寸
mm
mm
mm
mm
mm
m2
m2

mm
1.2
6
18
6
10.7
0.3
0.0018

1150×360×1.2
4.5.3 K值的计算[3]

图4-1逆流平均温差

物 料
水-水
水蒸汽(或热水)-油
冷水-油
油-油
气-水
K(W/(m2·℃))
2900～4650
870～930
400～580
175～350
28～58

可拆式板式换热器设计计算书
工艺条件
冷侧
热侧
介质名称
冷清水
热污水
流量
m3/h
51.67
52
热负荷
Kw
3259
温度 进→出
℃
25→70
90→35
流体类型
液
液
液
液
密度
Kg/m3
989.1
981.8
比热
KJ/kg.℃
4.174
4.178
导热系数
W/m.℃
0. 644
0.62
动力粘度
x10-6 Pa.S
616.8
419.1
对数平均温差
℃
14.43
计算换热面积
m2
72.85
计算传热系数
W/m2.K
4023
板片材料

密封胶垫材料
橡胶
板片数
243
压力降
MPa
0.08
0.08
流程组合
Counter flow
1x122
1x122
框架
设计压力
MPa
1
试验压力
MPa

设计温度
℃

5 板式换热器结构设计及强度校核
5.1 符号[5]
5.2 已知参数
板片厚度：S0=1.2
垫片中心线的展开长度：l=3020
垫片有效密封宽度：B=8
被垫片槽中心线包容的板片投影面积：a2=399510
设计压力：P=1
板间距：b=6
板片总数：NP=244
中间隔板数量：n1=0
中间隔板厚度：S2=0
垫片系数：=1
垫片比压力：y=1.4
5.3 结构设计及强度校核
表5-1压紧板厚度
单板公称换热
面积(m2)
在设计压力下的压紧板厚度()
设计压力()
0.6
1.0
1.6
2.0
2.5
0.1
0.3
0.5
0.7
0.8
1.0
2.0
25
35
45
50
55
60
80
25
40
50
55
60
65
80
30
50
55
60
65
70
80
30
50
55
60
－
－
－
35
55
60
－
－
－
－

材料
在下列温度下（℃）的弹性模量，×103
-20
20
100
150
200
250
碳素钢（c≤0.3％）
碳素钢（c﹥0.3％）、碳锰钢
高铬钢（Cr13～Cr17）
194
208
203
192
206
201
191
203
198
189
200
195
186
196
191
183
190
187
5.4 垫片
5.5 支柱设计及强度校核[6]

图5-5支座
表5-3 部分常用材料的a、b值
材料
a（MPa）
b（MPa）
适用范围
Q235钢
16Mn钢
铸铁
235
343
392
0.00668
0.0142
0.0361
λ=0～123
λ=0～102
λ=0～74
5.6 开孔补强

接管公称外径
25
32
38
45
48
57
65
76
89
最小厚度
3.5
4.0
5.0
6.0

参考文献

王毅.过程装备测试技术[M].北京：北京大学出版社，2010马履中.......
[5] 兰州石油机械研究所.板式换热器人字形波纹板片试验总结报告[J].1972
[6] GB16409-1996.板式换热器[S]
[7] 钱颂文等.换热器设计手册[M].北京：化学工业出版社，2002
[8] Flavio C.C, Galeazzo, Rsquel Y. et al. Ex-perimental and numerical heat transfer in a plate heat exchanger .Chemical Engineering Science, 2006(61) :7133-7138
[9] 常春梅.国内可拆卸板式换热器现状及发展趋势.石油化工设备. 2008，9（37，5）
[10] 赵晓文，苏俊林.板式换热器的研究现状及进展.冶金能源.2011，1
[11] 张晓锋.浅谈板式换热器.科技情报开发与经济.2009，10
[12] 邹同华，杜建通.板式换热器设计选型及使用中应注意的问题.设计与安装
[13] 李永新，杨峰，陈文强.板式换热器失效原因分析及维修方法.工业·生产，2006，4

DESIGN OF HEAT EXCHANGER FOR HEAT RECOVERY IN CHP SYSTEMS

ABSTRACT

The objective of this research is to review issues related to the design of heat recovery unit in Combined Heat and Power (CHP) systems. To meet specific needs of CHP systems, configurations can be altered to affect different factors of the design. Before the design process can begin, product specifications, such as steam or water pressures and temperatures, and equipment, such as absorption chillers and heat exchangers, need to be identified and defined. The Energy Engineering Laboratory of the Mechanical Engineering Department of the University of Louisiana at Lafayette and the Louisiana Industrial Assessment Center has been donated an 800kW diesel turbine and a 100 ton absorption chiller from industries. This equipment needs to be integrated with a heat exchanger to work as a Combined Heat and Power system for the University which will supplement the chilled water supply and electricity. The design constraints of the heat recovery unit are the specifications of the turbine and the chiller which cannot be altered.

INTRODUCTION

Combined Heat and Power (CHP), also known as cogeneration, is a way to generate power and heat simultaneously and use the heat generated in the process for various purposes. While the cogenerated power in mechanical or electrical energy can be either totally consumed in an industrial plant or exported to a utility grid, the recovered heat obtained from the thermal energy in exhaust streams of power generating equipment is used to operate equipment such as absorption chillers, desiccant dehumidifiers, or heat recovery equipment for producing steam or hot water or for space and/or process cooling, heating, or controlling humidity. Based on the equipment used, CHP is also known by other acronyms such as CHPB (Cooling Heating and Power for Buildings), CCHP (Combined Cooling Heating and Power), BCHP (Building Cooling Heating and Power) and IES (Integrated Energy Systems). CHP systems are much more efficient than producing electric and thermal power separately. According to the Commercial Buildings Energy Consumption Survey, 1995 [14], there were 4.6 million commercial buildings in the United States. These buildings consumed 5.3 quads of energy, about half of which was in the form of electricity. Analysis of survey data shows that CHP meets only 3.8% of the total energy needs of the commercial sector. Despite the growing energy needs, the average efficiency of power generation has remained 33% since 1960 and the average overall efficiency of generating heat and electricity using conventional methods is around 47%. And with the increase in prices in both electricity and natural gas, the need for setting up more CHP plants remains a pressing issue. CHP is known to reduce fuel costs by about 27% [15] CO released into the atmosphere. The objective of this research is to review issues related to the design of heat recovery unit in Combined Heat and Power (CHP) systems. To meet specific needs of CHP systems, configurations can be altered to affect different factors of the design. Before the design process can begin, product specifications, such as steam or water pressures and temperatures, and equipment, such as absorption chillers and heat exchangers, need to be identified and defined.

The Mechanical Engineering Department and the Industrial Assessment Center at the University of Louisiana Lafayette has been donated an 800kW diesel turbine and a 100 ton absorption chiller from industries. This equipment needs to be integrated to work as a Combined Heat and Power system for the University which will supplement the chilled water supply and electricity. The design constraints of the heat recovery unit are the specifications of the turbine and the chiller which cannot be altered.

Integrating equipment to form a CHP system generally does not always present the best solution. In our case study, the absorption chiller is not able to utilize all of the waste heat from the turbine exhaust. This is because the capacity of the chiller is too small as conditioning in the buildings considered remains an issue which can be resolved through the use of this CHP system.

BACKGROUND LITERATURE

The decision of setting up a CHP system involves a huge investment. Before plunging into one, any industry, commercial building or facility owner weighs it against the option of conventional generation. A dynamic stochastic model has been developed that compares the decision of an irreversible investment in a cogeneration system with that of investing in a conventional heat generation system such as steam boiler combined with the option of purchasing all the electricity from the grid [21]. This model is applied theoretically based on exempts. Keeping in mind factors such as rising emissions, and the availability and security of electricity supply, the benefits of a combined heat and power system are many.

CHP systems demand that the performance of the system be well tested. The effects of various parameters such as the ambient temperature, inlet turbine temperature, compressor pressure ratio and gas turbine combustion efficiency are investigated on the performance of the CHP system and determines of each of these parameters [1]. Five major areas where CHP systems can be optimized in order to maximize profits have been identified as optimization of heat to power ratio, equipment selection, economic dispatch, intelligent performance monitoring and maintenance optimization [6].Many commercial buildings such as universities and hospitals have installed CHP systems for meeting their growing energy needs. Before the University of Dundee installed a 3 MW CHP system, first the objectives for setting up a cogeneration system in the university were laid and then accordingly the equipment was selected. Considerations for compatibility of the new CHP setup with the existing district heating plant were taken care by some alterations in pipe work so that neither system could impose any operational constraints on the other [5]. Louisiana State University installed a CHP system by contracting it to Sempra Energy Services to meet the increase in chilled water and steam demands. The new cogeneration system was linked with the existing central power plant to supplement chilled water and steam supply. This project saves the university $ 4.7 million each year in energy costs alone and 2,200 emissions are equivalent to 530 annual vehicular emissions.

Another example of a commercial CHP set-up is the Mississippi Baptist Medical Center. First the energy requirement of the hospital was assessed and the potential savings that a CHP system would generate [10]. CHP applications are not limited to the industrial and commercial sector alone. CHP systems on a micro-scale have been studied for use in residential applications. The cost of UK residential energy demand is calculated and a study is performed that compares the operating cost for the following three micro CHP technologies: Sterling engine, gas engine, and solid oxide fuel cell (SOFC) for use in homes [9].

The search for different types of fuel cells in residential homes finds that a dominant cost effective design of fuel cell use in micro - P exists that is quickly emerging [3]. However fuel cells face competition from alternate energy products that are already in the market. Use of alternate energy such as biomass combined with natural gas has been tested for CHP applications where biomass is used as an external combustor by providing heat to partially reform the natural g