印尼煤掺烧设备性能分析及热值边界评估

Equipment performance analysis and calorific value boundary evaluation for Indonesian coal blending burning

为评估超临界锅炉掺烧印尼煤后的设备性能及入炉煤热值边界,以某超临界660 MW机组为例,开展了煤质特性及热重实验室分析、现场试验及理论计算,并对掺烧印尼煤后各设备的性能、裕量,以及受系统、设备裕量所限的热值边界进行了研究。结果表明:掺烧印尼煤后的入炉煤热值边界主要受制粉系统干燥出力及引风机出力所限;目前的设备条件及煤质下,按照各受限因素计算的入炉煤热值边界从低到高分别为锅炉安全运行、磨煤机碾磨出力、一次风机出力、制粉系统干燥出力、引风机出力;当入炉煤热值大于20.18 MJ/kg,若空气预热器压差维持良好,则无需设备改造,低于该值时,不同入炉煤热值范围则对应不同设备改造。

In order to evaluate the equipments performance and calorific value boundary of coal entering the furnace for supercritical boiler after blending Indonesian lignite,laboratory analysis of coal quality and thermogravimetric properties,field test and theoretical calculation were carried out,by taking a supercritical 660 MW unit as an example.Moreover,the equipments performance and margin of the supercritical boiler after blending Indonesian lignite,and calorific value boundary limited by the system or equipment margin were studied.The results show that,the calorific value boundary after blending Indonesian coal is mainly limited by the drying output of pulverizing system and the output of induced draft fan.Under the current equipment conditions and coal quality,the calorific value boundary of coal entering the boiler calculated according to each limited factor from low to high are safe operation of boiler,milling output of coal mill,output of primary fan,drying output of pulverizing system and output of induced draft fan.When the calorific value of the coal entering the furnace is greater than 20.18 MJ/kg,meanwhile the pressure difference of the air preheater is maintained in good condition,no equipment transformation is needed.While when the calorific value of the coal entering the furnace is lower than 20.18 MJ/kg,different equipment transformations are needed corresponding to different calorific value ranges of the coal entering the furnace.