摘要：针对气力输送过程中存在严重能量损失问题, 在水平管气力输送系统的粒子入口附近安装砂丘模型, 探讨系统最小压力损失和最小输送速度;为了揭示砂丘模型的节能机理, 采用粒子图像测速 (PIV) 技术和快速傅里叶变换 (FFT) 分别对各个工况加速区的粒子平均速度和粒子脉动速度进行测量与分析。结果表明:同样的空气输送速度下, 安装砂丘模型进行输送时, 粒子平均速度和粒子脉动速度的功率谱密度峰值明显大于传统气力输送系统, 并且自相关系数呈现准周期变化;粒子脉动速度的两点相关系数明显大于传统的气力输送系统;在管顶部附近, 粒子速度脉动强度大于传统的气力输送系统。

关键词：气力输送；粒子图像测速；最小输送速度；粒子脉动速度；功率谱密度

Abstract：The dune model was mounted on the bottom of conveying pipe near the inlet of particle feed for the problem of energy loss serious in pneumatic conveying to study the minimum pressure and minimum conveying velocity. To reveal the mechanism of the low conveying velocity and saving-energy conveying with dune model, PIV (particle image velocimetry) technology was developed to measure and analyze the time-averaged particle velocity and particle fluctuation velocity for all cases in the acceleration region. The study focuses on the effect of the different locations of dune model on the horizontal pneumatic conveying in terms of the time-averaged particle velocity, power spectrum, autocorrelation coefficients, two-point correlation coefficients and fluctuation intensity of particle velocity. It is found that the time-averaged particle velocity and power spectra peaks of particle fluctuation velocity are higher than that of non-dune on the same air velocity for all cases, and the auto-correlation coefficients of particle fluctuation velocity display a quasi-periodical wave. Meanwhile, the two-point correlation coefficients of particle fluctuation velocity and fluctuation intensity of particle velocity is larger than that of non-dune.

Keywords：pneumatic conveying；PIV；minimum conveying velocity；particle fluctuation velocity；power spectrum