煤粉群燃火焰中碳黑生成机理的研究

项目名称： 煤粉群燃火焰中碳黑生成机理的研究

项目编号： No.51476088

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 能源与动力工程

项目作者： 张海

作者单位： 清华大学

项目金额： 80万元

中文摘要： 雾霾是我国当前迫切需要解决的重大民生问题，而形成雾霾的微细颗粒的一个重要来源是燃煤锅炉排放的碳烟。尽管碳烟的研究开展了数十年，但基本仍局限于简化的燃烧环境，实际燃烧系统中碳烟的生成机理仍是燃烧界的一个挑战，煤粉锅炉中煤粉燃烧以群燃火焰的形式进行，其中碳烟的生成机理和影响机制还有待揭示。本项目以煤粉群燃火焰为对象，在与实际锅炉接近的、可控的燃烧环境进行开展实验研究，使用多种光学测量方法和传统采样方法相结合，采用最新研究报道的有效消除煤粉、飞灰等大颗粒对测量结果的干扰方法，定量地测定不同煤种和燃烧参数条件下碳烟在群燃火焰中的浓度分布、火焰内温度分布、煤焦颗粒分布和主要自由基分布，关联火焰特性与碳烟浓度分布特性，揭示群燃火焰中碳烟的生成机理和影响因素，建立生成模型，总结减少碳烟生成的措施，同时获得碳烟生成对煤粉火焰特征的反向影响规律，提出提高炉内燃烧和辐射传热计算精度的修正方法。

中文关键词： 煤粉燃烧；碳黑；群燃；火焰；生成机理

英文摘要： Haze is one of most urgent and important livelihood issues need to be resolved in China today, and the soot emitted from the coal-fired boilers is a major source of fine particles from which haze is formed. Although the studies on soot have being carried out decades, they are still mostly confined to simplified combustion environment, while the understanding of the soot formation mechanisms in practical combustion system is still a challenge for the international combustion society. In a pulverized coal boiler, combustion of coal occurs in a flame burning in cloud style, and the soot formation mechanisms in such a pulverized coal cloud flame remains to be revealed. In this proposed study, the soot formation in the pulverized coal cloud flame will be conducted. The experiments will be carried out to flames those are close to the practical flames in the pulverized coal boiler, under adjustable combustion conditions. Several advanced laser diagnostic methods as well as the traditional sampling methods will be applied to quantitatively measure the soot volumetric density, the temperature and major species distribution in the flame under different combustion conditions for different types of coal, using the latest reported tuning techniques to minimize the influence of coarse particles of char and ash. By correlating the flame characteristics with the soot distribution characteristics, it is expected the soot formation mechanism will be assessed and the major influencing factors on soot formation will be identified. The model to describe the soot formation process will be developed and the effective methods used for the soot formation reduction in the pulverized coal cloud flames will be summarized. In the meantime, the counter-influence of soot formation on the pulverized coal flame will be detected, and the correction for the calculation of coal combustion and the thermal radiation in the furnace will be proposed to improve the simulation accuracy.

英文关键词： Pulverized Coal Combustion;Soot;Cloud Combustion;Flame;Formation Mechanism