基于阵列式静电传感器的密相气力输送表观气速测量方法研究  

Research on the superficial gas velocity measurement method of dense-phase pneumatic conveying based on electrostatic sensor array

作　　者：高鹤明[1] 常琦[1] 晏克俊[1] 

机构地区：[1]西安理工大学机械与精密仪器学院,西安710048

出　　处：《仪器仪表学报》2015年第4期787-794,共8页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金项目(51406164;51405382);陕西省自然科学基础研究计划项目(2013JQ7005);陕西省教育厅专项(14JK1525);校科技创新项目(2013CX007)

摘　　要：高压密相气力输送是加压气流床煤气化的关键技术之一,对其表观气速的测量是监测其流动状态变化的重要依据,目前主要采用测量温度、压力、流量等参数进行间接计算的方法获取。本文提出一种基于阵列式静电传感器直接测量的新方法,利用阵列式静电传感器局部敏感特性,通过对每个电极获取的静电信号进行EMD分解得到其多尺度能量比,进而提取出其高频高能分量,并进行功率谱分析和等效频率计算,对各电极的等效频率进行加权平均从而获取加权频率,进而建立加权频率与表观气速的关系。通过对3种粒径褐煤煤粉输送的实验验证,结果表明该方法可行,能够建立加权频率与表观气速的线性关系,并且该线性关系的斜率随着输送颗粒粒径的增大而减小,同时也为测量颗粒粒径提供了新的手段。High-pressure dense-phase pneumatic conveying is a key technique of pressurized entrained flow gasification, and the measurement of superficial gas velocity is important for monitoring its flow state, which is now indirectly acquired through measuring temperature, pressure, gas mass flow and so on. This paper puts forward a fresh electrostatic sensor array based direct measurement method, which uses the local sen- sitive characteristics of electrostatic sensor array. The EMD decomposition is performed on the electrostatic signal of every electrode to calculate its multiscale energy ratio, then the high frequency and high energy component is extracted, and the PSD and equivalent frequency are calcu- lated; the weighted averaging of the equivalent frequencies of the electrodes is conducted and the weighted frequency is acquired. Finally the relationship between the weighted frequency and superficial gas velocity is established. To verify the measurement method, the conveying ex- periment on the lignite coal with three particle sizes was conducted. The experiment results indicate that the proposed method is feasible; the linear relationship between the weighted frequency and superficial gas velocity is established, and the slope of the linear relationship decreases with the increasing of the particle size. This method also opens up a new path for the particle size measurement.

关 键 词：静电传感器 颗粒荷电 气固两相流 多尺度 

分 类 号：TB934[一般工业技术—计量学] TH89[机械工程—测试计量技术及仪器]