摘要换热器就是指将热量从热流体传到冷流体的设备。换热器是一种通用设备，广泛用于很多地方例如：原子能，机械，电力，食品，医药，化工，石油和其他许多工业部门。在工业生产过程中，换热器的主要功能是降低热流体的流体温度从较高的温度，流体的温度达到标准的技术要求，以满足生产工艺的要求。另外，换热器是回收余热、废热尤其是低位热能的有效设备。
在本设计中，我设计了一个U形管式换热器。U型管换热器的构造特征是，有一块管板，上面有多根U型管组成管束，U型管的两端固定在相同一块管板上面，管子能够自由地伸缩。当有温差存在于壳体与U型换热管的时候，不会出现热应力。这种换热器的特点：管束可以自由地伸缩，不会因为管壳之间的温差而出现热应力，并且热补偿性能好；管束可以从壳体内抽出，清洁保养容易，结构简单，成本低廉。但是管内的清洗不方便，管束中央部分的管子比较难换，又由于最内层管子的弯曲半径不能过小，在管板的中央部分布管不紧凑，因而管子数不可以太多，而且管束中央部分存在空隙，使壳程中的流体容易短路进而影响壳程的换热。。另外，直管部分需要用管壁较厚的管子来弥补弯管后管壁的减薄。这样就影响其使用场合，只适合于管壳壁温相差较大，或者壳程介质易结垢。20818
本课题设计一个用以预热空气的空气预热器，其壳程中介质为空气，管程中介质为蒸汽。设计内容包括总体方案确定、物性参数确定，材料选择、细部结构（接管，折流板，法兰和管箱等）的设计，强度和稳定性校核。最后绘制了装配图和主要零部件图。
毕业论文关键词：换热设备，U型管换热器，结构特点
 Abstract
The equipment that transfers heat from hot liquid to the cool one is named as heat exchanger. It is a world-wide equipment that is widely used in pharmacy, chemical industry, oil refining, food, light industry, atomic energy, mechanism and many other departments of industry. In the industrial producing, transfer heat from higher temperature liquid to the lower one is the main role of the heat exchanger, it makes the temperature of liquid reach the stipulate target of technological process, in order to satisfy the requirements in technological process. In addition, the heat exchanger is effective equipment that can retrieve surplus heat and waste heat.
What I design is U-tube heat exchanger. The structure characteristics of U-tube heat exchanger is that there is only one tube plate, the tube bundle is make up of many U-tubes, both ends of the tubes are fixed on the same tube plates, the tubes can stretch out and draw back freely. When there is a temperature difference between the shell and the U-tube, there would not be thermal stress. The structure of the U-tube heat exchanger is simple, the price is cheap and the ability of bearing pressure is strong, it is adapt to the temperature difference between tube wall and shell wall is relative large or the medium of the shell are easy to scaling and unwell adopt float heat exchanger and fixed tube plate heat exchanger. Especially adapt to the materiel and supplies in the tube is high temperature, high pressure and large corrosive property.
This paper is to design a air preheater which is used to preheat air, its medium of shell side is air and that of tube side is steam. The content of this designment includes the determination of general planning and physical parameter, the choice of material, the designment of detailed parts (adapter, baffle plate, flange and channel, etc), and verification of strength and stability. Finally draw assembly drawing and the main parts.
Keywords:heat exchanger,U-tube heat exchanger,structure characteristic
目录
1 绪论    1
1.1 引言    1 ANSYS空气预热器的设计+CAD图纸:http://www.youerw.com/jixie/lunwen_12740.html