【作者】 李斌；

【导师】 吕太；

【作者基本信息】 东北电力大学 ， 热能工程， 2012， 硕士

【摘要】 近年来，我国能源需求超常规增长、电力短缺、石油进口依赖度不断增加，能源问题已经成为制约我国经济发展的重要因素之一。作为我国主要能源的煤炭的消费量将逐年扩大，NO_x作为燃煤电站锅炉的排放烟气的主要污染物之一，对环境造成严重的污染。截止到2008年底，我国200MW以下的机组占全国火电总装机容量的26%，这些中小机组对城市以及大气环境污染的贡献率却非常的高，控制其污染物的排放对我国的可持续发展有着重要的意义。本文以某电厂一台160t/h四角切圆燃煤锅炉为例，通过理论研究和数值模拟的方法，结合现场改造试验，研究锅炉的低NO_x燃烧改造技术。首先确定主燃烧区域的最低过量空气系数，以确定出的最低过量空气系数为基础进行理论计算，再结合现场的实践经验制定出具体的改造方案并绘制改造方案的图纸；其次，运用目前使用比较广泛的FLUENT数值计算软件对改造前后炉膛内的冷态空气动力、燃烧状况以及NO_x的浓度分布进行模拟，为实际改造提供一定的理论支持；最后，实施现场改造，改造完成后进行性能考核测试，验收改造效果。改造完成后NO_x的排放量降低了50%，与模拟结果基本吻合。此外，从模拟结果看出，由于重新分配了风和煤粉的混合，炉膛内煤粉的燃烧更加合理，使改造后锅炉的效率提高了0.88%，在改造的同时还兼顾了锅炉的经济性，达到了二者的双赢。更多还原

【Abstract】 Increasing energy demand, electricity deficiency and increasing dependence onoil importation are among the main energy problems that China is facing today.Energy problem is becoming more and more important. The consumption of coal isincreasing year by year， the combustion of fuels generate more and more NO_xemission, which can lead to serious atmosphere pollution. Until2008, the units under200MW took26%of the total installed capacity of the national thermal power in ourcountry; the pollution from them was serious for the cities. So control the pollution ofpower plant is important for the sustainable development of our country.A Corner-tangential-boiler of160t/h in a thermal power plant was studied in thethesis by means of theory and simulation and field tests, then the low NO_xcombustion modification technologies was researched.Firstly，make sure minimum excess air coefficient of the lord burning zone andcalculate on base of it. And then make out the specific reform plan combining withthe practical experience, and render the drawings of the reconstruction plan. Secondly,use the more extensive numerical calculation software FLUENT to simulate the coldair kinetic, combustion status and NO_xconcentration distribution, providingtheoretical support for real reform. Finally, implement the reform, and test theperformance evaluation after the completion, and check the reform effect.After the reform the NO_xemissions reduced by50%, which had a goodagreement with the simulation results. In addition, it is showed from the simulationresults that the pulverized coal was burned more reasonable because of theredistribution of wind and pulverized coal, which makes the boiler efficiencyincreased by0.88%after reform. Meanwhile the boiler’s economical efficiency wasconsidered, achieving both of the win-win.更多还原