大型燃煤发电机组NOx排放优化控制的研究

论文总字数：29839字

摘 要

本文的主要目的是基于一台1000MW超超临界锅炉机组，通过对锅炉燃烧和SCR系统运行的历史数据的分析，建立锅炉主要运行参数及SCR系统运行参数与机组NOx排放量之间的关系，并对SCR系统运行的经济性进行评价。

本文通过锅炉原理及燃烧学知识，对锅炉NOx的生成和机组NOx排放的主要运行参数的影响进行理论分析，结合机组运行的历史数据和理论分析结果，研究主要运行因素与锅炉NOx 排放量之间的关系并 给出数据分析结果。对SCR系统，给出影响SCR系统经济性的各种因素及其计算方法，以盈亏平衡点和敏感性为例给出SCR系统的经济性评价。

结果表明：机组负荷、燃烧氧量、SCR系统入口NOx浓度、注氨量对机组NOx排放量有较大的影响；随机组负荷的降低，锅炉NOx排放浓度增加；锅炉NOx排放量随着燃烧氧量的增加而增加；在低负荷运行时，SCR入口NOx浓度高，催化剂效率低，SCR出口NOx排放浓度高；随着注氨量的而增加，SCR出口NOx浓度显著减小。该机组的年利润与运行时间成正比，与催化剂价格与还原剂价格呈反比;运行时间对年利润的影响最大，催化剂价格与还原剂价格的对年利润影响近乎相同。

关键词：氮氧化物，低NOx燃烧技术，SCR技术，运行经济性

Study on optimal control of NOx emission from large-scale coal fired power generation units

Abstract

The main purposes of this thesis are, based on a 1000MW ultra supercritical boiler unit and through analyzing the historical data of the operation of the boiler combustion and SCR system, to establish the relationship between the main operating parameters of the boiler as well as the operating parameters of the SCR system and the NOx emissions of the unit and to evaluate the economy f the operation of SCR system.

In this thesis, the theoretical analyses on the influences of the operating parameters of boiler NOx formation and unit NOx emission were carried out by using the principle of the boiler and combustion science knowledge. Combining the historic data of the unit operation and the theoratical analysis results, the relationship between main operational parameters and boiler NOx emission was investigated and the data analysis results were provided. The various factors influencing the economy and its calculation method of economical analysis for the SCR system were given. Besides, the break-even point and sensitivity were given as an example for performing the economical evaluation of the SCR system.

The results showed that the unit load, combustion oxygen level, SCR system inlet NOx concentration, and ammonia injection amount have greater impact on the unit NOx emissions; Boiler NOx emission concentration increases with the decrease of the unit load; Boiler NOx emission increases with the increase of oxygen for the combustion; For low load operation, SCR inlet NOx concentration is high, catalyst efficiency is low, and consequently SCR outlet NOx concentration is high; SCR outlet NOx concentration decreases significantly with the injection of ammonia increased. The unit's annual profit is proportional to the operation time, and is inversely proportional to the prices of the catalyst and the agent; Operating time has the greatest impact on the annual profit, while the price of the catalyst and the price of the reducing agent have almost identical influences on the annual profit.

Keywords: Nitrogen oxides, low NOx combustion technology, SCR technology, operation economy

目 录

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

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

第一章 绪论 5

1.1 研究背景及意义 5

1.2 NOx排放控制技术应用现状 6

1.3 论文课题的目的和研究内容 7

第二章 NOx生成控制原理及其影响因素 8

2.0 引言 8

2.1 煤燃烧时NOx的生成控制机理 8

2.1.1 NOx的生成机理 8

2.1.2 NOx的还原机制 10

2.2 NOx的控制技术 10

2.2.1 低NOx燃烧技术 10

2.2.2 选择性催化还原（SCR）法 11

2.3影响燃煤机组NOx排放的主要因素 12

2.3.1 机组运行负荷的影响 12

2.3.2 燃料特性的影响 12

2.3.3 燃烧氧量的影响 13

2.3.4 一次风的影响 13

2.3.5 二次风的影响 13

2.3.6 燃尽风的影响 13

2.3.7 SCR系统入口NOx浓度对出口NOx浓度的影响 14

2.3.8 SCR系统入口温度对出口NOx浓度的的影响 14

2.3.9 SCR系统还原剂对出口NOx浓度的的影响 14

2.4小结 15

第三章 1000MW锅炉机组NOx排放特性及分析 16

3.0 引言 16

3.1 设备概况 16

3.1.1 锅炉设备 16

3.1.2 锅炉低NOx燃烧系统 17

3.1.3 SCR系统 19

3.1.4 设计煤种和校核煤种 20

3.2 锅炉机组运行历史数据的处理和分析 21

3.2.1 锅炉燃烧NOx排放浓度随机组运行负荷的变化 22

3.2.2 入炉燃料量对锅炉出口NOx排放浓度的影响 22

3.2.3 燃烧氧量对锅炉出口NOx排放浓度的影响 23

3.2.4紧凑燃尽风（CCOFA）对锅炉出口NOx排放浓度的影响 25

3.2.5分离燃尽风（SOFA）对锅炉出口NOx排放浓度的影响 25

3.2.6二次风对锅炉出口NOx排放浓度影响 26

3.2.7 SCR系统入口NOx浓度对SCR系统出口NOx浓度的影响 27

3.3.8 SCR系统入口温度对SCR系统出口NOx浓度的影响 27

3.3.9 还原剂对SCR系统出口NOx浓度的影响 28

3.3 小结 29

第四章 SCR系统的经济性分析 31

4.0 引言 31

4.1 SCR经济性分析概述 31

4.2 SCR脱硝成本构成与分析 31

4.3 SCR经济性分析 32

4.3.1 SCR系统盈亏平衡分析 33

4.3.1 SCR系统敏感性分析 35

4.4 小结 36

第五章 总结 37

致谢 38

参考文献 39

第一章 绪论

1.1 研究背景及意义

剩余内容已隐藏，请支付后下载全文，论文总字数：29839字