660MW超临界对冲火焰锅炉煤种燃烧适应性研究
发布时间：2018-08-30 21:02
【摘要】：在国内外近几年的能源背景下,我国以煤炭为主体的能源供给格局在未来很长一段时间内将不会改变。目前,许多火电厂锅炉燃用非设计煤种,导致锅炉燃烧不稳定,燃烧效率下降,炉膛结渣等问题。因此,研究大容量超临界机组锅炉燃用非设计煤种安全性和经济性,拓宽锅炉对燃烧煤种的适应性,是目前火力发电行业亟需改进或解决的重要研究课题。湖南某电厂地处湖南省邵阳市郊,燃煤主要采用邵阳周边劣质无烟煤与本地烟煤掺混,或与从外省采购的烟煤混配掺烧,运行中很难保证锅炉燃用设计煤种。为拓宽该电厂锅炉对燃用非设计煤种的适应性,本文针对该电厂660MW超临界对冲锅炉实际运行过程燃煤的情况,挑选了最有可能燃用的20种单煤及15种混煤进行炉内燃烧的适应性分析。首先,对选取的煤样进行工业分析、元素分析、发热量等常规分析及热重分析,了解各煤种的煤质特性及燃烧特性,以此作为炉内传热计算的基础。之后,根据该电厂660MW超临界锅炉炉膛的设计尺寸、结构特点,建立传热计算数学模型,对原苏联的分区传热计算方法进行改进细化,把燃烧区域细分为三个区段,进行改进后的炉膛分区传热计算。通过计算得到在100%,75%,50%三种负荷情况下,燃用不同煤种时,沿炉膛高度的烟气温度及受热面平均热强度的分布情况。根据传热计算结果,结合各煤种的煤质特性和燃烧特性,判断得出在不同负荷下对锅炉的适应性较好煤种。同时,挑选出9个适炉煤种进行了锅炉热态试验验证。通过现场试验,验证数学模型的准确性,并结合测量的燃烧污染物排放和灰渣可燃物含量等因素,对煤种燃烧与锅炉的适应性进行综合性判断。研究结果表明：所建立传热计算模型能合理反映出不同煤种在超临界对冲火焰锅炉炉内燃烧的传热情况。在660MW.500MW、330MW三种负荷下,最适合锅炉燃烧的煤种分别为发热量大于18.5MJ/kg,9%Vdaf≤19%且C/H较大的武冈龙坪新矿煤、发热量大于21.0MJ/kg,CM在20左右的混煤SS64和邵阳七里山老井煤。
[Abstract]:Under the background of domestic and foreign energy in recent years, the energy supply pattern with coal as the main body in our country will not change for a long time in the future. At present, many thermal power plant boilers burn non-designed coal, which results in unstable combustion, low combustion efficiency, slagging in furnace and so on. Therefore, to study the safety and economy of burning non-designed coal in large capacity supercritical unit boiler, and to broaden the adaptability of boiler to burning coal type, is an important research subject that needs to be improved or solved in the thermal power generation industry at present. A power plant in Hunan Province is located in the suburbs of Shaoyang City, Hunan Province. Coal burning is mainly mixed with inferior anthracite and local bituminous coal around Shaoyang, or mixed with bituminous coal purchased from other provinces. It is difficult to ensure boiler burning design coal in operation. In order to broaden the adaptability of the power plant boiler to burning non-designed coal, this paper aims at the case that the 660MW supercritical boiler in the power plant is used to hedge the actual operation process of the boiler. Twenty kinds of single coal and 15 kinds of mixed coal which are most likely to burn are selected to analyze the adaptability of combustion in furnace. Firstly, the industrial analysis, element analysis, calorimetric analysis and thermogravimetric analysis of the selected coal samples are carried out to understand the coal quality characteristics and combustion characteristics of each coal, which is used as the basis of heat transfer calculation in the furnace. Then, according to the design size and structural characteristics of the furnace of 660MW supercritical boiler in this power plant, the mathematical model of heat transfer calculation is established, and the calculation method of heat transfer in the former Soviet Union is improved and refined, and the combustion area is divided into three sections. The improved heat transfer calculation of furnace is carried out. The distribution of flue gas temperature and average heat intensity of heating surface along the furnace height is obtained by calculation under three kinds of loads of 100% 75% and 50%, when different kinds of coal are burned. According to the results of heat transfer calculation and combined with the coal quality characteristics and combustion characteristics of each kind of coal, it is concluded that the adaptability of coal to boiler is better under different loads. At the same time, 9 kinds of suitable coal were selected to verify the hot state of boiler. The accuracy of the mathematical model is verified by field test, and the adaptability of coal combustion to boiler is judged synthetically by combining the measured factors such as combustion pollutant discharge and ash and slag combustible content. The results show that the heat transfer calculation model can reasonably reflect the heat transfer of different kinds of coal combustion in supercritical flame boiler furnace. Under three kinds of loads of 660MW. 500MW / 330MW, the most suitable coal types for boiler combustion are the coal of Wugang Longping new coal mine, whose calorific value is greater than 18.5 MJ / kg ~ (9) V _ (daf) 鈮，
本文编号：2214283
[Abstract]:Under the background of domestic and foreign energy in recent years, the energy supply pattern with coal as the main body in our country will not change for a long time in the future. At present, many thermal power plant boilers burn non-designed coal, which results in unstable combustion, low combustion efficiency, slagging in furnace and so on. Therefore, to study the safety and economy of burning non-designed coal in large capacity supercritical unit boiler, and to broaden the adaptability of boiler to burning coal type, is an important research subject that needs to be improved or solved in the thermal power generation industry at present. A power plant in Hunan Province is located in the suburbs of Shaoyang City, Hunan Province. Coal burning is mainly mixed with inferior anthracite and local bituminous coal around Shaoyang, or mixed with bituminous coal purchased from other provinces. It is difficult to ensure boiler burning design coal in operation. In order to broaden the adaptability of the power plant boiler to burning non-designed coal, this paper aims at the case that the 660MW supercritical boiler in the power plant is used to hedge the actual operation process of the boiler. Twenty kinds of single coal and 15 kinds of mixed coal which are most likely to burn are selected to analyze the adaptability of combustion in furnace. Firstly, the industrial analysis, element analysis, calorimetric analysis and thermogravimetric analysis of the selected coal samples are carried out to understand the coal quality characteristics and combustion characteristics of each coal, which is used as the basis of heat transfer calculation in the furnace. Then, according to the design size and structural characteristics of the furnace of 660MW supercritical boiler in this power plant, the mathematical model of heat transfer calculation is established, and the calculation method of heat transfer in the former Soviet Union is improved and refined, and the combustion area is divided into three sections. The improved heat transfer calculation of furnace is carried out. The distribution of flue gas temperature and average heat intensity of heating surface along the furnace height is obtained by calculation under three kinds of loads of 100% 75% and 50%, when different kinds of coal are burned. According to the results of heat transfer calculation and combined with the coal quality characteristics and combustion characteristics of each kind of coal, it is concluded that the adaptability of coal to boiler is better under different loads. At the same time, 9 kinds of suitable coal were selected to verify the hot state of boiler. The accuracy of the mathematical model is verified by field test, and the adaptability of coal combustion to boiler is judged synthetically by combining the measured factors such as combustion pollutant discharge and ash and slag combustible content. The results show that the heat transfer calculation model can reasonably reflect the heat transfer of different kinds of coal combustion in supercritical flame boiler furnace. Under three kinds of loads of 660MW. 500MW / 330MW, the most suitable coal types for boiler combustion are the coal of Wugang Longping new coal mine, whose calorific value is greater than 18.5 MJ / kg ~ (9) V _ (daf) 鈮，
本文编号：2214283
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