低氮改造后过热器超温及NO_(x)排放高原因分析  

Cause Analysis on Burner Superheater Overtemperature and High NO Emission after LNB Retrofit

作　　者：陈安合 郭秋实 周亚男 杨磊 张孝勇 任福虎 CHEN An-he;GUO Qiu-shi;ZHOU Ya-nan(China Datang Corporation Science and Technology Research Institute Co.,Ltd,Thermal Power Technology Research Institute;Inner Mongolia Datang International Toketo Power Generation Co.,Ltd.)

机构地区：[1]中国大唐集团科学技术研究院有限公司火力发电技术研究院,北京100040 [2]内蒙古大唐国际托克托发电有限责任公司

出　　处：《电站系统工程》2021年第6期81-84,共4页Power System Engineering

摘　　要：为了保证低氮改造方案的安全性、经济性和环保性,以某电厂480 t/h锅炉的低氮改造为例,通过分析其改造后出现的过热器超温、减温水量高、NO_(x)排放浓度高等问题的原因,得出其改造方案存在缺陷:(1)原煤粉燃烧器浓淡分离效果欠佳,引起降氮效果差,着火热偏高、着火延迟,火焰中心上移;(2)燃尽风喷口设计三层,且为"瘦高型"挤占了燃尽空间,引起火焰中心上移,从而引起过热器超温、减温水量大从而限负荷的问题。在此基础上,采取了相应的改进措施。结果表明,改进措施有效解决了汽温超温限负荷和NO_(x)排放浓度高的问题。In order to ensure the safety, economy and lower NO_(x) emission of the boiler after low nitrogen retrofit, taking the low nitrogen retrofit of 480 t/h boiler in a power plant as an example, by analyzing the causes of superheater overtemperature, high desuperheating water and high NO_(x) emission concentration after retrofit, it is concluded that the retrofit scheme has defects:(1)The fuel separation effect of the burner is not good, resulting in poor nitrogen reduction effect, high ignition heat, ignition delay, the center of the flame moved up.(2)The design of the separated over fire air has three layers, and the "lower width and large height "burner nozzles occupies the exhausted space, which increases the flame center, thus causes several problems such as superheater overheating, attemperation water flow too large and limited boiler load. Based on the above analysis, the corresponding improvement measures are carried out. The results show that the problems existing on boiler are solved effectively. The improvement can provide guidance on solving similar problems for other power plants.

关 键 词：低氮燃烧器改造 过热器超温 NO_(x)排放 

分 类 号：TK227[动力工程及工程热物理—动力机械及工程]