不同收光方式下煤粉流的等离子体信号探测

针对煤粉流组分分布的不均匀性, 研究不同收光方式对煤粉流的激光诱导等离子体的光谱信号收集效果的影响.选用电厂常用燃煤神木混为实验对象,利用自行搭建的气固两相流实验台架产生稳定煤粉流,对比同向收光方式和侧向收光方式下煤的特征谱线信号探测的强度和稳定性.研究结果表明,相同实验条件下,中间穿孔反射镜使同向收光方式下探测的光谱信号强度较弱,而等离子体信号源位置沿激光束轴线的变化、等离子体信号本身沿空间分布的不均匀性及煤粉流的阻挡作用使侧向收光方式下探测的光谱信号稳定性较弱.

Investigation on Collection Performances of Plasma Signal for Pulverized Particle Coal Flow in Different Optical Collection

In order to reduce the adverse impact of the inhomogeneous of pulverized coal components, different optical path systems were set up and used to research the collection performances of plasma of pulverized coal by laser-induced breakdown spectroscopy. The coal samples, Shenmuhun, was chosen for experiment. The detected count and stability of special lines of coal in different optical collection were investigated on the self-built two-phase particle flow experiment bench, which was used to produce stable pulverized coal stream. The analysis results show that in the steadily repeat measurements, the counts of the lines collected by back-side are weaker because of the intermediate perforated mirror, while the stability of the lines collected by side are worse because of the position change of plasma along the laser beam, the spatial inhomogeneity of plasma and the blocking effect of pulverized coal.