摘 要

余热锅炉是利用烟气及工艺生产出的余热来产出蒸汽的一种锅炉。在提高能源利用效率和节约能源方面 , 除采用高能效的新设备和先进工艺外, 采用余热锅炉也是提高能源利用率的重要手段。本课题就是对80万吨/年炭素烟气余热锅炉进行的热力计算及结构设计。

由于炭素烟气余热锅炉运行中烟气具有一定的含硫量，因其较高的露点温度，当其壁温低于露点温度时，就会发生低温腐蚀，所以应控制烟气温度，从而有效控制金属壁温以保证锅炉的平稳运行。炭素烟气余热锅炉系统中的省煤器可能会发生管壁结焦情况，这是由于烟气中含有一定量的硫及水分，造成低温腐蚀，可以适当提高省煤器壁温。

在设计过程中应注意烟道水平布置。余热锅炉的蒸发器采用翅片管式蒸发器，传热管水平布置，烟气在管外流动放热，水在管内吸热蒸发。省煤器采用径向热管省煤器。其中蒸发器与省煤器的迎风面宽度不能超过限宽标准，其中烟气的工况流速应满足自清灰要求。热力计算中应注意蒸发器与省煤器的总压降应低于800Pa，以此来满足阻力损失要求。

具体设计思路如下：烟气流经蒸发器与省煤器，进口烟气温度为350℃，出口烟气温度为170℃，进口水温为104℃，蒸发器与省煤器均采用双进双出管子排布，汽包设计应满足遭遇各种意外事故而导致没有水量补充时，系统仍能运行15分钟的要求，以此方便采取应急措施。

本课题对整个余热锅炉系统中的主要运行设备进行施工图设计，其中包括系统总图，蒸发器部分，省煤器部分及主要零部件图。

关键词：炭素烟气 余热锅炉 低温腐蚀 阻力损失

Design of 800,000 tons/year carbon flue gas waste heat boiler

Abstract

Waste heat boilers are boilers that use flue gas, process gas, and waste heat from products to produce steam. In order to increase energy efficiency and save energy, in addition to adopting new energy-efficient equipment and new processes, the use of waste heat boilers to recover various types of waste is also an important means of improving energy efficiency. This topic is the thermal calculation and structural design of a 800,000-ton/year carbon flue gas waste heat boiler.

Because the carbon in the operation of the flue gas waste heat boiler flue gas has certain sulfur content, the dew point temperature is higher, and when the wall temperature is lower than the dew point temperature, will lead to low temperature corrosion, so should be paid attention to in the process of the operation of the waste heat boiler flue gas temperature control, thus effectively control metal wall temperature.Carbon in the flue gas waste heat boiler system economizer tube wall coked might happen, this is because the smoke contains a certain amount of sulfur and moisture, cause corrosion at low temperature, can raise the economizer wall temperature.

In the design process should pay attention to flue level arrangement.The evaporator of the waste heat boiler USES the finned tube evaporator, the heat transfer pipe horizontal arrangement, the flue gas outside the pipe flow exothermic, the water in the tube absorbs heat to evaporate.The economizer adopts the radial heat pipe economizer.The width of the windward face of the evaporator and the economizer should not exceed the limit of the limit, and the flow rate of the gas should meet the requirement of self-cleaning.In thermal calculation, the total pressure drop of evaporator and economizer should be less than 800Pa to meet the resistance loss requirement.

Specific design idea is as follows: flue gas flows through the evaporator and the economizer, inlet flue gas temperature is 350 ℃, the outlet flue gas temperature is 170 ℃, inlet water temperature of 104 ℃, evaporator and economizer adopts double in double out the pipe arrangement and drum design should meet the confronted with all kinds of accidents and cause no water added, the system can still run for 15 minutes, which is convenient to take emergency measures.

This project designs the main equipment of the whole waste heat boiler system, including the system general drawing, the evaporator part, the economizer part and the main parts diagram.

Key words：Carbon flue gas ；waste heat boiler； low temperature corrosion ；Friction loss

目录

摘要 Ⅰ

Abstract Ⅱ

第一章 绪论 1

1.1课题的研究背景及目的 1

1.2余热锅炉的分类 1

1.3新型余热锅炉的特点 1

1.4炭素技术 2

1.4.1炭素工业的发展 2

1.4.2余热回收在炭素工艺中的运用 2

1.5炭素烟气余热锅炉运行时可能遇到的问题 3

1.6炭素余热锅炉实例 3

1.7课题的重要性及意义 5

第二章 80万吨/年炭素烟气余热锅炉设计 6

2.1设计要求 6

2.2炭素烟气余热锅炉设计中要考虑的问题 6

2.3图纸设计中要考虑的问题 6

第三章 热力计算书及结构设计 7

3.1原始设计参数 7

3.2余热锅炉系统设计 7

3.2.1热平衡计算 7

3.3蒸发器的设计 10

3.3.1蒸发器的热力计算 10

3.3.2蒸发器结构计算 12

3.4省煤器的设计 17

3.4.1省煤器的热力计算 17

3.4.2省煤器结构计算 20

3.5施工图设计 25

第四章 总结 26

参考文献 27

致谢 29

第一章 绪论

1.1课题的研究目的与背景

目前能源利用技术的主要课题是在节约能源的基础上提高能源利用效率和开发新节能技术^[1]。