1000MW超超临界燃煤锅炉低NOx燃烧优化试验研究
摘要：为实现锅炉低NOx燃烧优化,在某1000MW对冲燃烧的锅炉省煤器出口水平段烟道建立试验平台。通过改变氧量、OFA挡板开度、二次风配风及燃烧器投运方式,研究不同工况下NOx生成特性。结果表明,氧量变化对炉膛火焰温度的影响不大,燃料型NOx的生成是影响NOx排放量的主导因素,热力型NOx的影响几乎可以忽略。随着OFA挡板开度增大,炉内火焰的平均温度水平下降,省煤器出口NOx排放浓度下降,CO体积浓度上升。OFA全开时,NOx排放浓度虽然能控制在较低的水平,但CO体积浓度急剧上升,兼顾NOx排放浓度和锅炉运行的经济性,建议燃尽风风门挡板开度控制在80%左右。对比四种配风方式,正塔配风下煤粉燃尽率和炉内火焰的平均温度水平最高,且NOx排放浓度不高,仅比束腰配风高3.57%。投运下层燃烧器比投运上层燃烧器NOx排放质量浓度降低了16.82%,减少上层燃烧器投运,有利于分级燃烧并抑制NOx的生成,也可在一定程度上降低炉膛出口烟气温度,对控制屏式受热面的结焦有利。
Abstract:An experiment platform was built on a 1000 MW boiler in opposed firing pattern for low-NOx combustion optimization. The formation characteristics of NOx in different working conditions were studied by changing the oxygen concentration,air damper position of over-fired air(OFA),the distribution of second-air and combinations of burners. The results indicated that the effect of different oxygen concentrations on temperature of flue gas in furnace was very small. The formation of fuel-NOx was the leading factor of increasing NOx emission,and the effect of thermal-NOx was almost negligible. With OFA increasing,average temperature of flame in furnace and NOx emission decreased,CO volume concentration increased. When the damper position of OFA was at 100%,the NOx emission could be controlled at a low level,but the CO volume concentration rapidly became greater. Considering NOx emission concentration and economy of boiler,OFA could be controlled at around 80%. Comparing the four types of air distribution mode,pulverized coal burning rate and the average temperature of the flame in the furnace the highest level in the pagoda-shaped air distribution type,and NOx emission concentration was not high,only 3.57% higher than the waist-shaped air distribution.The experiments also confirmed that NOx emission decreased 16.82% under the lower burner operation mode compared with the upper burner operation mode. Reducing the operation of the upper burner could inhibit the formation of NO_x through pulverized coal staging combustion,and control the coking of platen super-heater by reducing furnace outlet flue gas temperature in a certain extent.
标题：1000MW超超临界燃煤锅炉低NOx燃烧优化试验研究
title:Experimental Study on Low NOx Combustion Optimization of 1000MW Ultra-supercritical Coal-fired Boiler
作者：宋华伟, 李允超, 李凯, 张海珍, 李鹏辉
authors:SONG Hua-wei, LI Yun-chao, LI Kai, ZHANG Hai-zhen, LI Peng-hui
关键词：对冲燃烧,低NOx,分级燃烧,
keywords:opposed firing,low NOx,staging combustion,
发表日期：2017-08-30
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