【作者】 邓涛；

【导师】 岑可法； 池作和；

【作者基本信息】 浙江大学 ， 工程热物理， 2004， 硕士

【摘要】 火电厂燃煤产生的NOx排放严重地影响着环境、气候和人类的健康，是一个迫切需要解决的问题。NOx对环境的污染问题，国内外开发了许多抑制NOx的技术，其中煤粉再燃是一种比较有效的方法。本文对煤粉再燃的脱氮效果、煤粉燃烬等关键问题，进行了研究。 经过对国内许多燃煤试验台的调研，设计并搭建了具有多种用途的一维热态试验系统，从该半工业性试验台上所取得的数据对实际工程具有指导意义。试验台上可进行煤粉燃烧和超细粉再燃试验，模拟煤粉炉内NOx的生成和还原过程。 本文通过测定煤粉细度、分析孔隙结构以及热重分析等试验，得到了煤粉粒径变化后煤粉特性的变化趋势。并对超细煤粉的物理、燃烧特性进行了试验研究，这为研究超细煤粉再燃过程及再燃过程中的煤粉燃烬提供了基础。 在热态试验系统上进行了煤粉再燃中NOx排放特性的研究。通过大量的试验，得出了煤种、煤粉细度、炉膛温度和过量空气系数等因素对NOx排放。在此基础上，研究了超细煤粉再燃及煤种、煤粉细度、炉膛温度过量空气系数和停留时间等因素对NOx排放，试验结果表明超细煤粉再燃对降低NOx排放有效果，但意义不明显。 由于试验台的高度有限，对煤粉颗粒的燃烬进行了部分试验，没有进行广泛的研究。在文中主要从煤粉颗粒燃烧的简化模型和数值模拟两方面进行了探讨。研究表明，煤粉颗粒的尺寸大小、燃烧环境中的氧量及环境温度对煤粉的燃尽或燃尽时间有很大的影响。更多还原

【Abstract】 Pollutant NOx emitted by coal combustion power plant is an increasing threat to environment and human health, which becomes an urgent problem to be solved. Many efficient methods have been developed for solving the NOx emission problem in world wide, one of them is coal reburning. In this paper, pulverized coal reburning technology is brought forward and a lot of researches are carried out aiming at the key issues of fuel reburning such as NOx reduction efficiency and burnout rate.After surveying many coal-burnt-furnace inside of our country, a one-dimensional test system with multi-function is designed and built up. This system is a pilot-scale facility and can get instructive results for business utility. With this testing-bed, research for pulverized coal burning or micronized coal reburning can been put in practice, productive and reductive process of NOx can be simulated in this furnace.The results of the change tendency of pulverized coal character with particle diameter are got from particle diameter determining test, hole structure analysis test and TG analysis test in this paper. And research on physics and combustion characteristic of micronized coal is putted off, which provide a basis for researching reburning process and burnout of particle with micronized coal reburning.Using this system, researches on NOx emission with coal reburning are carried out. The results of influence on NOx emission by coal type, coal particle diameter, furnace temperature and excess air are reached through experiences. Based on these, micronized coal reburning tests are processed, and also the influence on NOx emission by coal type, coal particle diameter, furnace temperature, excess air and residence time, which show a slightly effect results on NOx reduction.But with the height limitation of test bed, a few experiences for burnout are gone on, not for abroad investigation. Calculate with simplified model and numerical simulation for burnout of coal are discussed. Study shows that particle diameter, oxygen and temperature of combustion environment play an important role on burnout or time for burnout of coal.更多还原