煤质特性对激光等离子体的影响

Influence of coal characteristics on laser-induced plasmas

为研究煤质特性对激光等离子体的影响,选取8种代表性煤样为实验对象,首先对煤样进行了元素分析和工业分析,并通过实验研究激光与不同煤样之间的相互作用,分析了水分、灰分等对激光等离子体的影响。试验结果表明,煤化程度不同的煤呈现出不同的等离子体时间谱;在等离子体形成的初期,时间谱均呈上升趋势(<1μs),随着等离子体信号的衰减,曲线呈单调下降趋势(约1μs后),煤化程度高的煤种在激光作用约2μs之后发生二次电离;在相同实验条件下,不同煤种的等离子体温度不同,煤化程度越高等离子体温度越高。

Eight kinds of typical coal samples were chosen for studying the influence of coal characteristics on laser-induced plasmas. Element analysis and industry analysis were carried out for every sample. Experimental study on the interaction between laser and different coal samples was completed, and factors affecting laser plasma were analyzed, such as coal moisture and coal dust. The experiment result indicates that the coal samples with different coalification degrees have different plasma time-resolved spectral characteristics, all of them tend to rise at the beginning of plasma formation （〈1μs）, then with the decay of plasmas emission, they tend to decrease in about 1μs, while secondary ionization occurs in highly coalificated coals after 2 μs. The plasma temperature differs from one kind to another, the higher the coalification degree is, the higher the plasma temperature will be.