【作者】 刘毅；

【导师】 陈刚；

【作者基本信息】 华中科技大学 ， 热能工程， 2011， 硕士

【摘要】 我国是能源生产与消耗的大国,国情决定了我国以煤为主的能源结构,但是热力发电厂在燃煤过程中排放的NO_x气体对大气环境造成了极大的危害,因此控制燃煤电厂NO_x等污染气体的排放成为了我国经济发展过程中重要的目标。O₂/CO₂循环燃烧技术是一种高效、经济、环保的新一代燃烧技术,它能够大量减少燃烧过程中CO₂、NO_x、SO_x等气体的排放,降低燃煤对环境的危害。本文主要研究这种技术在控制煤粉燃烧NO_x释放方面的作用。首先,在实验室管式炉装置上,利用烟气分析仪研究两种单煤印尼煤和山西优混煤在不同气氛下NO_x前驱物HCN、NH₃以及NO_x等污染物的释放特性,得出它们的释放速率曲线和释放总量,通过比较分析这些曲线的特点得出了煤粉在不同气氛下热解时HCN、NH₃等气体的释放规律;通过分析连续的释放速率曲线得出煤种、气氛、O₂/CO₂气氛下氧浓度等因素对它们释放特性的影响。其次,对上述两种单煤及其混煤进行了常规分析和热重试验,分析了煤种的煤质特性和灰成分。通过求得的TG、DTG曲线分析研究了混煤的燃烧特性,求解了印尼煤和山西优混煤及其混煤的着火特性参数、燃尽特性参数和混煤燃烧的化学动力学参数,得出了混煤掺烧后对燃烧特性的影响。最后,在混煤煤质特性和燃烧特性的研究基础上,通过管式炉试验装置,分析研究了混煤在不同气氛下NO释放规律,特别是O₂/CO₂气氛下氧浓度和二氧化碳浓度的改变对混煤NO释放的影响。通过试验分析,得出了混煤掺烧对于NO等污染物排放的影响。更多还原

【Abstract】 Energy production and consumption is huge in our China, national conditions decide the coal-dominated energy structure. But the NO_x emissions from coal-fired power plants cause great harm to atmospheric environment, so controlling Coal-fired power plant NO_x pollution and other gas emissions has become an important economic development goal of the process. O₂/CO₂ cycle combustion technology is an efficient, economic and environmentally friendly next-generation combustion technology, it can significantly reduce the combustion process in CO₂, NO_x, SO_x and other gas emissions, reduce the harm to the environment. This paper studies the efficacy of this technology in controlling the release NO_x from coal combustion.First of all, in the tube furnace devices, by using an infrared gaseous analyser, release characteristics of NO_x precursors HCN, NH₃ and NO_x from two single coals Indonesia Coal and Shanxi-youhun Coal under different combustion atmosphere were investigated, and got their total release rate curve and their total release amount. By comparing the characteristics of these curves, the releasing characteristics of HCN, NH₃ and other gases form coal at different atmosphere during pyrolysis were investigated, and then analysed the efficacy the factors such as coal characteristics, the atmosphere, and the oxygen concentration in O₂/CO₂ atmosphere do to the release from them.Secondly, the coal element composition was measured and made the TGA experiment of the two single coals and its blended coals, analysis of coal properties and ash content of coal. The TG, DTG curve of the mixed coal combustion characteristics were obtained, and the combustion characteristics of blended coals were investigated, the ignition characteristics, burnout characteristics of Indonesia Coal and Shanxi-youhun Coal and chemical kinetic parameters in combustion were analysed, so that the efficiency after mixing the coal to the burning combustion characteristics was obtained.Finally, on this basis, in the tube furnace equipment, the NO releaseing from blended coals under different atmosphere was investigated, especially the effect of carbon dioxide, oxygen concentration in O₂/CO₂ atmosphere on NO releaseing. Through test analysis, the effect of the mixed coal combustion to the emissions of pollutants such as NO was obtained.更多还原