浓相粉煤灰气力输送差压波动ARMA功率谱分析

ARMA Power Spectrum Analysis of Differential Pressure Fluctuation in Dense-Phase Pneumatic Conveying of Fly Ash

在料罐体积均为0.6m3,输送管内径为20mm,输送距离为20m的试验台上进行浓相气力输送试验研究。采用ARMA功率谱分析输送过程中固气比对气体表观速度、压力损失和能量在频域分布的影响。结果显示:随着固气比的增加,表观速度降低,单位长度的压力损失逐渐增大,差压波动逐渐减小;功率在频域内分布随着固气比增大逐渐向低频移动,主峰峰值也随之增大。这些均与粉煤灰流动形态有关。它揭示了功率在频域内的分布情况,对研究管内运动和能量交换提供了新的研究途径。

Dense-phase pneumatic conveying experiments of fly ash were carried out on test rig composed of the hoppers of 0.6 m3 and stainless pipeline of 20 mm inside diameter for a total length of 20 m. ARMA power spectral density analysis was used to investigate the influence of sol- id/gas ratio on gas superficial velocity, pressure drop and power distribution in the frequency region. Experimental results indicate that superficial velocity reduces, pressure drop increases and differen- tial pressure fluctuation flattens with increasing solid/gas ratio. Power distribution in the frequency region removes to low frequency and main peak value increases when solid/gas ratio increases. All of these are related to pulverized coal flow pattern. This paper reveals the power spectral density distribution in the frequency region and offers a new approach to investigate movement and energy exchange in the pipes.