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本研究在激光全散射法颗粒物浓度检测系统上进行了不同性质、浓度燃煤飞灰颗粒的质量浓度测量实验。结果显示,联合全散射法颗粒物浓度检测系统和反演计算方法能良好的测算标准颗粒的质量浓度,误差约为7%。对于燃煤飞灰颗粒,测算结果能反映气流中颗粒浓度的变化,然而测算值高于真实值约19.3%~27.2%。并且,对除尘器前级电场飞灰的测算偏差大于第四电场飞灰。进一步的理论计算结果表明,随颗粒粒径增大,散射光分布逐步向前向(即0°方向)集中,导致光电探测器在收集透射光的同时收集部分前向散射光,使得反演计算值大于真实值。而前级电场飞灰中含有更多的大粒径、非球形颗粒且粒径分布范围更宽,偏离了反演算法的假定条件,导致对测算偏差增大。
In this study, the mass concentration measurement of coal-fired fly ash particles with different properties and concentrations was carried out on the laser total scattering particle concentration detection system. The results show that the combined total scattering particle concentration detection system and inversion calculation method can well measure the mass concentration of standard particles with an error of about 7%. For coal-fired fly ash particles, the calculation result can reflect the change of particle concentration in the air stream, however, the calculated value is higher than the true value of about 19.3% -27.2%. Moreover, the deviation of the measured fly ash from the electric field at the front stage of the precipitator is greater than that of the fourth electric field fly ash. Further theoretical calculations show that as the particle size increases, the scattered light gradually concentrates in the forward (ie, 0 ° direction) direction, causing the photodetector to collect some of the forward-scattered light while collecting the transmitted light so that the inverse calculation The value is greater than the true value. The former electric field fly ash contains more large particles, non-spherical particles and a wider range of particle size distribution, deviate from the assumption of the inversion algorithm, resulting in increased measurement error.