Abstract

The ignition thresholds and kinetic characteristics of the glow of flames under the action of nanosecond laser pulses (τ_i = 14 ns) of a YAG:Nd³⁺ laser (λ = 1064 nm) on coals of DG (long-flame gas), G (gas), Zh (fat), and K (coking) grades from the Kuznetsk Basin were measured. The stages associated with the evaporation of microprotrusions on the surface of particles and the development of an electron avalanche were distinguished. The threshold \(H_{{{\text{cr}}}}^{{(1)}}\) did not depend on the coal grade. The glow amplitude was a nonlinear function of H, and the kinetics of glowing contained two components with τ₁ ~ 20 ns and τ₂ ~ 1 μs. When the energy density \(H_{{{\text{cr}}}}^{{(2)}}\) was reached, glow in a microsecond time interval was observed due to the ignition of the coke residue. The ignition threshold \(H_{{{\text{cr}}}}^{{(2)}}\) decreased with an increase in the degree of coalification and a decrease in the volatile matter content.

中文翻译：

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在自由运行模式下通过激光脉冲点燃煤

摘要

YAG:Nd ³⁺激光（λ = 1064 nm）在纳秒激光脉冲（τ _i = 14 ns）作用下火焰辉光的点火阈值和动力学特性（长焰气体），测量了库兹涅茨克盆地的 G（天然气）、Zh（脂肪）和 K（焦化）品位。区分了与粒子表面微突起蒸发和电子雪崩发展相关的阶段。阈值\(H_{{{\text{cr}}}}^{{(1)}}\)不依赖于煤炭品位。辉光振幅是H的非线性函数，辉光动力学包含两个分量，τ ₁ ~ 20 ns 和 τ ₂ ~ 1 μs。当能量密度\(H_{{{\text{cr}}}}^{{(2)}}\)，由于焦炭残渣的点燃，观察到微秒时间间隔内的发光。着火阈值\(H_{{{\text{cr}}}}^{{(2)}}\)随着煤化程度的增加和挥发分含量的降低而降低。