论文总字数：17549字

摘 要

高炉热风炉作为炼铁工业重要的设备之一，它可以源源不断向炉内提供1000℃以上的高温热风，以使炉内的铁矿石还原成金属铁，从而得到较纯净的钢材。然而该工艺过程中排出的烟气具有300～400℃的温度，若不加以利用，将会造成很大的能量损失。本课题就是针对小型高炉热风炉的空气预热器进行设计，充分回收烟气余热，达到节能减排的目的。

本课题以T66导热油作热媒设计热媒式空气预热器，采用间接取热的方式，能够更好的控制壁温在烟气露点温度以上，同时传热管水平放置，翅片表面竖着，有利于积灰的沉降。在进行余热回收的过程中也会遇到一些问题，由于排出的烟气含有硫化物等使得烟气露点温度提高，当烟气温度低于露点温度时，将容易引起露点腐蚀。另外在空气预热器温度较低的区域容易引起积灰沉降，久而久之形成堵塞，影响空气预热器的正常运行。

然后进行热力计算，思路如下：275℃的烟气进入烟气换热器加热导热油后的出口温度控制在150℃以下，由于被烟气间接加热的空气和煤气具有相同的出口温度，可以根据空气和煤气的流量和进口温度确定烟气是如何分配的，然后根据导热油的进出口温度计算出所需导热油的流量。为保证导热油流速符合工艺要求，同时要满足烟气和空气的阻力降＜600Pa，对结构方面进行了相关设计。整个装置设计时应保证正常工作，强度达标，导热油流通顺畅自如。

最后，对整个余热回收系统的主要设备进行了图纸设计，包括系统图、烟气、空气换热器总图及主要部件的零件图。

关键词：高炉热风炉 热媒 空气预热器 导热油 余热回收

The design of hot medium air preheater for 580m³ blast furnace hot blast stove

Abstract

As one of the important equipments in ironmaking industry, blast furnace hot blast stove can continuously provide high temperature hot air above 1000 C to the furnace, so tha thet iron ore in the furnace can be reduced to metal iron, and thus more pure steel can be obtained. However, the flue gas discharged from the process has a temperature of 300 to 400℃, If it is not utilized, it will cause a great energy loss. The purpose of this paper is to design the air preheater of small blast furnace hot blast furnace, to fully recover the waste heat of flue gas, and achieve the purpose of energy saving and emission reduction.

In this paper, T66 heat conduction oil is used as heat medium to design heat medium air preheater. By using indirect heat collection, the wall temperature can be better controlled above the dew point temperature of flue gas, at the same time, the heat transfer pipe is placed horizontally and the finned surface is vertical, which is beneficial to the settlement of ash accumulation. Some problems will also be encountered in the process of waste heat recovery. Since the exhausted flue gas contains sulfides etc, the dew point temperature of flue gas will be increased, and when the flue gas temperature is lower than the dew point temperature, it will easily cause dew point corrosion. In addition, in the area where the temperature of the air preheater is low is easy to cause ash accumulation and settlement, resulting in blockage over time, which affects the normal operation of the air preheater..

Then the thermodynamic calculation is carried out, and the ideas are as follows: After the 275℃flue gas enters the flue gas heat exchanger to heat the heat transfer oil, the outlet temperature is controlled below 150℃. Since the air and gas indirectly heated by the flue gas have the same outlet temperature, it is possible to determine how the flue gas is distributed according to the air and gas flow and the inlet temperature, and then the flow rate of the required heat conduction oil can be calculated according to the inlet and outlet temperature of the heat conduction oil. In order to ensure that the flow rate of heat conduction oil meets the technological requirements and the resistance drop of flue gas and air is less than 600 Pa, the related structural design is carried out. The whole device should be designed to ensure normal operation, the strength is up to standard, and the heat transfer oil flows smoothly and freely.

Finally, the main equipment of the whole waste heat recovery system is designed, including the system diagram, the general diagram of the flue gas and air heat exchanger, and the part drawing of the main components.

Key Words: Blast furnace hot blast stove; Heat medium; Air perheate; Heat conduction oil; Waste heat recovery

目 录

摘 要 I

ABSTRACT II

第一章 绪论 1

1.1课题研究的背景及目的 1

1.2高炉热风炉烟气余热回收 1

1.3空气预热器的发展 2

1.3.1管式空气预热器 2

1.3.2热管式空气预热器 2

1.3.3板式空气预热器 3

1.3.4旋转式空气预热器 3

1.4烟气余热回收过程中的问题 4

1.4.1空气预热器的低温露点腐蚀 4

1.4.2空气预热器的积灰堵塞 4

1.5导热油作热媒的余热回收系统 4

1.5.1导热油简介 4

1.5.2导热油热媒系统的基本原理 5

1.5.3导热油热媒系统的优点 5

1.6 课题的必要性及意义 5

第二章 580m³高炉热风炉热媒式空预器的设计 7

2.1设计要求 7

2.2高炉热风炉热媒式空预器的设计中要考虑的问题 7

2.3热力计算中遇到的问题 7

2.4图纸设计中遇到的问题 8

第三章 热力计算 9

3.1课题给定要求 9

3.2烟气加热导热油换热器的设计 10

3.2.1热平衡计算 10

3.2.2阻力降计算 13

3.3导热油加热空气换热器的设计 19

3.3.1热平衡计算 19

3.3.2阻力降计算 20

第四章 结构设计 27

4.1主要零部件选型 27

4.2施工图设计 27

第五章 总结 28

参考文献 29

致谢 32

第一章 绪论

1.1课题研究的背景及目的

我国的能源资源种类非常多，但是不同能源的总量和分布很不均匀，即煤炭资源充足，而石油、天然气等资源相对缺乏，从而构成了我国以煤炭为主的能源结构^[1]。

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