论文总字数：20347字

摘 要

目前，大多数焦化厂直接将焦炉烟道废气通过烟囱排放至大气，造成了极大的能源浪费。在当前提倡循环经济、可持续发展的背景下，对焦炉烟道废气余热进行回收利用，具有巨大的经济效益和节能减排意义。基于这一现实背景，本文设计了一台“12万Nm³/h焦炉水平烟道烟气余热锅炉”，以回收焦炉烟道排放的大量烟气余热。通过对锅炉给水进行预热，产生170℃左右的蒸汽，从而达到提高能源利用率和节能减排的目的。

焦炉煤气燃烧后烟气中含有大量的水和二氧化硫。因此，焦炉烟道废气余热回收利用需解决焦炉烟道废气成分复杂，含硫量较高等问题。由于省煤器在烟气出口处管壁温度常常低于露点，容易产生低温露点腐蚀，而且在余热回收的时候可能会影响焦炉生产、破坏焦炉的压力操作制度，现行的余热回收技术就显得不太经济。然而，利用余热锅炉回收焦炉烟道气的余热技术就能够较好地解决上述问题，在烟气温度低于或接近露点腐蚀温度的省煤器上采用热管作为换热单元，在烟气温度高于露点腐蚀温度的蒸发器区域采用翅片管。这样设计能够在提高换热系数的同时解决金属结构的低温腐蚀问题。

在设计过程中，已知烟气和水的进、出口温度、压力、流量等参数，根据热平衡方程，计算出了传热量和水蒸汽流量，然后选择合适的翅片管和热管，确定其结构参数，计算出总传热系数和总传热面积，并分别确定了蒸发器和水预热器内部的传热面结构参数，从而确定锅炉的整体布置。

本课题在设计过程中参照了《工程流体力学》、《锅炉原理》、《压力容器设计手册》、《换热器设计手册》等相关资料。在满足烟气的流动压力降及水动力循环等各项指标的前提下，综合考虑结构设计、现场安装等需要的前提下，设计出了焦炉水平烟道烟气余热锅炉的施工总图、汽包和换热器主体图以及主要的零部件图，同时对汽包、传热管等材料进行了强度校核，使其满足工作环境下的强度要求。本次设计结果满足任务书的设计要求，在安全性和经济性及环保要求方面均合格。

关键词：焦化 烟气 余热锅炉

The design of 120,000 Nm³/h horizontal coke flue gas waste heat boiler

Abstract

Currently, most coking plants emitted coke oven flue gas to the atmosphere through the chimney directly, this caused a great waste of energy. In the current context of promoting circular economy and sustainable development, waste heat recovery and utilization have enormous economic and energy conservation significance. Based on this background, a boiler has been designed to recovery the waste heat of coke oven flue gas, in which the flue gas flow rate is 120,000 Nm³/h and its flow path is horizontal. The feed water was heated to be saturated steam with the temperature 170℃ by this boiler to achieve the objective of improving energy efficiency, energy saving and emission reduction.

In the flue gas, there is a lot of water and sulfur dioxide after the combustion of coke oven gas. So there exist the problems of coke oven flue components and high sulfur content in the waste heat recovery and utilization process. If the economizer tube wall temperature was might below the dew point of the flue gas and it was easy to produce low-temperature dew point corrosion, this may affect the production and destroy the pressure of coke oven operation system, the traditional economizer of waste heat recovery technology was not very economical. However, the heat pipe has been used to be as the heat transfer element in the economizer of the waste heat boiler to recovery flue gas of coke oven to protect the dew point corrosion. Finned tubes have been used in the evaporator because its wall temperature is above the dew point temperature. This design can improve heat transfer coefficient and avoid the low temperature corrosion problem of metal structure at the same time.

In the process of design, the parameters of inlet and outlet temperatures of flue gas and water, steam pressure, volume flow rate of flue gas are known. According to heat balance equation, the biography heat and steam flow were calculated out. Then by selecting suitable fin tablets tube and pipe, the structure parameters of the evaporator and the economizer were determined after the total heat transfer coefficient and total heat transfer area have been calculated out, in which the internal heat transfer surface area was determined.

In the design process, the Engineering Fluid Dynamics, the principle of the boiler, Pressure vessel design manual, the heat exchanger Design Handbook and other related information have been referred. Under the condition of meeting the flue gas flow pressure drop and the targets hydrodynamic circulation, the needs of structure design, installation and others were considered. The construction of horizontal flue coke oven flue gas waste heat boiler and boiler and heat exchanger, as well as major components have been designed out. The strength of drum, tubes and other materials to make it meet the strength requirements in the working environment was checked, too. The total design meets the requirements of the mission statement.

Key words: Coking; Tlue gas; Waste heat boiler

目录

摘要……………………….......................................................……………………..……………I

Abstract …………………………………...................................………………..…………….II

目录……………………………………..................................…………………..……………IV

第一章 绪论………………………………………….................................……..……………1

1.1 焦炉烟道气余热回收技术简介………..................…………………………………….1

1.2 焦炉烟道废气余热利用技术……...................…………………………………………1

1.2.1热管技术…….......................………………………………………………………1

1.2.2 煤调湿…….....................…………………………………………………………2

1.3 余热锅炉………………...................……………………………………………………2

1.3.1 余热锅炉的分类…………….....................………………………………………2

1.3.2 烟气余热………………………….....................…………………………………2

1.4 焦炉烟气余热回收原理………………...........................………………………………3

1.5 焦炉余热回收的特点及技术上存在的主要问题……...................……………………3

第二章 热力计算和结构设计….......................……………………………………………5

2.1 蒸发器的热力计算……...................……………………………………………………5

2.2 蒸发器的结构设计……...................……………………………………………………8

2.3 省煤器的热力计算….....................……………………………………………………12

2.4 省煤器的结构设计….....................……………………………………………………14

第三章 余热锅炉的结构设计…............................………………………………………19

3.1传热器本体结构设计………...............................………………………………………19

3.2壳体结构设计…………………...............................……………………………………19

3.3 余热锅炉水循环系统的汽包设………….........................……………………………19

3.4设备法兰的确定…………………...............................…………………………………20

3.5设备支座的选取………….....................………….…….....……………………………20

3.6施工图设计…………................….…………….…….....………………………………20

第四章 强度校核……………………................…............…………………………………21

4.1汽包筒体的强度校核……...............................…………………………………………21

4.2 汽包封头的强度校核……….............................………………………………………21

4.3翅片管的强度校核………………...........................……………………………………22

4.4热管的强度校核………………...........................………………………………………23

4.5 流体输送管的强度校核……….........................………………………………………24

4.6 联合管的强度校核…………………….....................…………………………………25

第五章 水动力循环校核……………..............................…………………………………28

5.1下降管中的沿程阻力及局部阻力计算…………...................…………………………28

5.2上升管中汽液两相流体的流动阻力及局部阻力计算….......................………………29

5.3第二排翅片管的沿程阻力及局部阻力计算………….......................…………………31

5.4第一排翅片管的沿程阻力及局部阻力计算…………...................……………………32

请支付后下载全文，论文总字数：20347字