摘要
国内电厂锅炉燃煤品质变化大,煤发热量的在线测量对于优化机组控制、提高运行稳定性和经济性有重要作用。给出一个基于炉膛燃烧和传热反问题的煤质测量模型,在某1 000 MW超临界锅炉上实现了燃煤发热量的在线监测。化学燃烧计算确定了煤的各种元素含量与炉膛出口烟气成分之间的联系;炉膛辐射传热量是煤质、燃煤量、过量空气系数以及热风温度等变量的函数,对于直流锅炉,辐射传热量还可根据受热面内的工质进、出口参数准确地计算;在炉膛燃烧和传热方程中,煤元素含量和发热量是测量模型的求解目标。该煤质测量模型在实际运行锅炉上投入运行,数值模拟及现场试验表明,发热量扩展不确定度u95 1342.4 kJ/kg,与现场实际试验结果相符。
In domestic power plant with highly inhomogeneous fuels, it is desirable to get real time fuel characteristics for unit control optimization and operational stability improvement. A soft sensing model of calorific value of coals based on inverse coal combustion and furnace radiation problems was presented, it enabled the possibilities of continuously measuring the calorific value of solid fuels in a 1 000 MW supercritical pressure once-through boiler. To do so, the links between the content of coal elements and the flue gas constituents in the furnace were built through fuel chemical calculations. Radiation heat transfer, which can be accurately calculated according to working fluid parameters for the once-through boiler, is a function of variables such as coal quality, coal-fired flow, excess air ratio and combustion air temperature. The elemental contents and calorific value of coal are solving target in coal combustion and heat transfer equations. The coal soft-sensing model has been put into service in a utility boiler, measurement simulation and field tests show that the expanded uncertainty of calorific value of coal u95 is1342.4kJ / kg, which is in good agreement with test results.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2013年第17期8-15,5,共8页
Proceedings of the CSEE
关键词
超临界直流锅炉
发热量测量
辐射换热
煤燃烧
supercritical pressure once-through boiler
calorific value sensor
radiation heat transfer
coal combustion
