基于不同标准的锅炉热效率及发电标准煤耗率修正方法

Correction of Boiler Thermal Efficiency and Standard Coal Consumption Rate Based on Different Standards

对不同标准中规定的锅炉输入热量计算方法进行了分析,指出同一机组在同一工况下,只有在基准温度与燃料温度和空气预热器入口空气温度相等且雾化燃油所消耗的蒸汽量为零时,依据不同标准得到的锅炉热效率以及由此得到的发电标准煤耗率才完全相同.基于锅炉热效率反平衡计算表达式,采用微分方法并结合泰勒公式,得到燃料温度、空气预热器入口空气温度、所采用的基准温度以及煤种偏离基准参数时,引起锅炉热效率和发电标准煤耗率偏差的计算方法,并以某2台300MW凝汽式机组为例进行了计算验证.结果表明:将试验工况下的锅炉热效率和发电标准煤耗率修正到同一基准参数下时,不同机组之间的锅炉热效率和发电标准煤耗率才具有可比性.

By analyzing the boiler heat input calculation methods specified in different standards,it is found that for the same unit under same operation conditions,only when the benchmark temperature,the fuel temperature and the inlet air temperature of air preheater are equal,and no steam is consumed for oil atomization,will the boiler thermal efficiency obtained based on different standards and the standard coal consumption rate thus gained be completely the same.According to the anti-balance calculation expression of boiler thermal efficiency,using differential method combined with Taylor formula,a calculation method is proposed for variation of boiler thermal efficiency and standard coal consumption rate caused by deviation of fuel temperature,inlet air temperature of air preheater,benchmark temperature adopted and the coal grade from corresponding reference data.The method is subsequently verified with two 300 MW condensing type units.Results show that the boiler thermal efficiency and standard coal consumption rate are comparable among different units under experimental conditions when they are corrected to the same benchmark parameters.