【作者】 邹维祥；

【导师】 柳朝晖；

【作者基本信息】 华中科技大学 ， 热能工程， 2007， 硕士

【摘要】 全球变暖、温室效应是由于CO₂为代表的温室气体的大量排放导致的温室效应的加剧而造成的。在降低CO₂排放所带来的影响的策略上,不外乎控制CO₂的产生和回收处理。富氧燃烧技术就是在这一背景下提出来的。富氧燃烧技术也称为O₂/CO₂燃烧技术,或空气分离/烟气再循环技术。富氧燃烧技术不仅能使分离收集CO₂和处理SO₂容易进行,还能减少NOx排放,是一种能够综合控制燃煤污染物排放的新型洁净燃烧技术。本文首先综合概述该技术的发展状况和研究现状,以及煤粉燃烧特性的主要研究进展,分析了其中的成果和不足,从而明确了自己的研究思路。继而针对四种不同煤粉,利用热天平研究了其在不同条件下的燃烧状况,观察了O₂/CO₂气氛下煤粉的着火与燃尽。在此基础上,针对滴管炉制得的不同温度下的神华、大同煤焦,在热天平上用非等温热重法分析了O₂/CO₂气氛下的燃烧特性,观察了热解温度对焦活性的影响,以及氧分压对燃烧的影响,得到了各自的表观反应动力学参数,发现大同煤焦的反应处于两个不同的反应阶段,神华煤焦的活性明显高于大同煤焦,且低温焦的反应性比高温焦要好;考虑到CO₂气化反应的存在,本文进而用等温热重法研究了两种煤焦的气化反应动力学,发现低温焦气化活性高于高温焦,随着气化温度的升高,神华、大同两种煤焦的气化反应性均增强。更多还原

【Abstract】 World warming is due to the worse of Greenhouse effect mainly by massive CO₂ emission. Among many Greenhouse gases, CO₂ contributes the biggest to Greenhouse Effect due to its long lifetime and massive emission. CO₂ mainly comes from the combustion of fossil fuels. The amount of CO₂ emission becomes larger, as the development of economics and the demand for energy. In the case of controlling CO₂ emission, various advanced methods should be combined together to fit different cases. The effect of CO₂ could be debated by way of controlling CO₂ production or disposing recovered CO₂.Up to now, many methods have been developed to controlling CO₂ production. The oxygen-enriched combustion technology has been proposed to increase CO₂ concentration. Part of flue gas will be circulated and mixed with oxygen to be loaded into furnace. Oxygen-enriched combustion is also called as O₂/CO₂ combustion, or air separation and flue gas recycle. CO₂ separation and SO₂ treatment become easier, NOx emission is reduced in oxygen-enriched combustion technology. Oxygen-enriched combustion is one of the new clean coal combustion technology that can control pollutant emission.An overview of the main progress of oxygen-enriched combustion technology was given, followed with the comment and criticism of these research achievements and some development of combustion characteristics of pulverized coal. Then, Non-isothermal thermo-gravimetry experiment on four different pulverized coal was conducted in order to research the combustion characteristics of pulverized coal in CO₂ atmosphere with different conditions, especially the igniting and burnout.Secondly, other TG experiments on coal char made in drop tube furnace with different temperature were conducted. We can analysis the reactivity kinetics of char by the results of these experiments. And the results show that the larger of the oxygen content is, the lower of the igniting temperature and the burnout temperature are. Meanwhile we can see that the reactivity of char made in lower temperature is superior than that of char made in higher temperature. In the end, we conducted the gasification experiment of char with different reactivity temperature. And the results show that the higher of gasification temperature is, the higher of the char gasification activity and the gasification activity of shenhua char is higher than that of datong char.更多还原