基于递归分析的生物质与惰性颗粒混合流动压差脉动信号混沌分析

Chaotic analysis of pressure fluctuation of quartz sands flow mixed with biomass particles based on recurrence analysis

将递归图及其定量分析方法应用于双组分流化床流动混沌分析中,对大颗粒生物质(当量直径为5 mm,密度为350 kg/m3)与石英砂(直径为0.4 mm,密度为2 700 kg/m3)在流化床内混合流动的压差脉动信号进行持续10 s的采样提取,并对其进行递归图和递归定量分析。研究结果表明:在鼓泡流状态下生物质颗粒的存在降低床内流动的随机性,增强系统的平稳性。系统的确定性和周期性随着气速的增加而增强。而当气速小于最小流化风速时,床内流动接近固定床状态,递归特征值的变化规律不明显,系统的随机性较强。

The recurrence plot（RP） and recurrence quantification analysis（RQA） were used in the chaotic analysis of two-component flow in fluidized-bed. Pressure fluctuation signals generated by the fluidized bed flow were sampled for 10 min, and were analyzed by RP and RQA. The materials of the research were the mixture of biomass（equivalent diameter： 5 mm, density： 350 kg/m3） and silica sands（diameter： 0.4 mm, density： 2 700 kg/m3）. The results show that the existence of biomass decreases the chaos properties but improves the reliability of the dynamic system in the fluidized bed on the bubbling conditions. However, there is not obvious regularity on the characteristic value when the velocity is below the minimum fluidizing gas velocity and the flow pattern in the bed is close to fixed bed, which means a strong randomness of the system.