核主元分析方法（Kernel Principal Component Analysis,KPCA）能有效地捕捉数据的非线性特征,其故障检测能力很大程度上取决于核参数的选择。常用的核函数有多项式核函数和高斯径向基核函数等。该方法将多项式核函数和高斯径向基核函...核主元分析方法（Kernel Principal Component Analysis,KPCA）能有效地捕捉数据的非线性特征,其故障检测能力很大程度上取决于核参数的选择。常用的核函数有多项式核函数和高斯径向基核函数等。该方法将多项式核函数和高斯径向基核函数进行线性组合,结合两者优点得到混合核函数,使用故障检测率作为优化目标的适应度函数,通过人工蜂群（Artificial Bee Colony Algorithm,ABC）优化算法对KPCA核参数的选取进行优化。将该方法应用到电主轴的转子不平衡故障分析中,对信号进行时域分析,利用KPCA对样本数据进行非线性特征提取,根据主元特征计算出的T2和SPE统计量实现故障检测。经过对实验数据分析表明,ABC优化算法较二分法、粒子群等优化算法能更有效地提高故障检测率。展开更多
This paper presents the experimental investigations of the emissions of SO2, NO and N20 in a bench scale circulating fluidized bed combustor for coal combustion and co-firing coal and biomass. The thermal capacity of ...This paper presents the experimental investigations of the emissions of SO2, NO and N20 in a bench scale circulating fluidized bed combustor for coal combustion and co-firing coal and biomass. The thermal capacity of the combustor is 30 kW. The setup is electrically heated during startup. The infuence of the excess air, the degree of the air staging, the biomass share and the feeding position of the fuels on the emissions of SO2, NO and N2O were studied. The results showed that an increase in the biomass shares resulted in an increase of the CO concentration in the flue gas, probably due to the high volatile content of the biomass. In co-firing, the emission of SO2 increased with increasing biomass share slightly, however, non-linear increase relationship between SO2 emission and fuel sulfur content was observed. Air staging significantly decreased the NO emission without raising the SO2 level. Although the change of the fuel feeding position from riser to downer resulted in a decrease in the NO emission level, no obvious change was observed for the SO2 level. Taking the coal feeding position R as a reference, the relative NO emission could significantly decrease during co-firing coal and biomass when feeding fuel at position D and keeping the first stage stoichiometry greater than 0.95. The possible mechanisms of the sulfur and nitrogen chemistry at these conditions were discussed and the ways of simultaneous reduction of SO2, NO and N2O were proposed.展开更多
基金Project supported by the National Natural Science Foundation of China (No. 90210034, 50576101,20221603)
文摘This paper presents the experimental investigations of the emissions of SO2, NO and N20 in a bench scale circulating fluidized bed combustor for coal combustion and co-firing coal and biomass. The thermal capacity of the combustor is 30 kW. The setup is electrically heated during startup. The infuence of the excess air, the degree of the air staging, the biomass share and the feeding position of the fuels on the emissions of SO2, NO and N2O were studied. The results showed that an increase in the biomass shares resulted in an increase of the CO concentration in the flue gas, probably due to the high volatile content of the biomass. In co-firing, the emission of SO2 increased with increasing biomass share slightly, however, non-linear increase relationship between SO2 emission and fuel sulfur content was observed. Air staging significantly decreased the NO emission without raising the SO2 level. Although the change of the fuel feeding position from riser to downer resulted in a decrease in the NO emission level, no obvious change was observed for the SO2 level. Taking the coal feeding position R as a reference, the relative NO emission could significantly decrease during co-firing coal and biomass when feeding fuel at position D and keeping the first stage stoichiometry greater than 0.95. The possible mechanisms of the sulfur and nitrogen chemistry at these conditions were discussed and the ways of simultaneous reduction of SO2, NO and N2O were proposed.
