电容层析成像在煤粉料仓下料中的应用

Application of electrical capacitance tomography in hopper discharge of pulverized coal

煤粉料仓下料是气流床粉煤气化工艺中粉体供料单元的重要组成部分,其安全稳定运行具有重大的经济意义。提出将电容层析成像(ECT)技术用于煤粉料仓下料,从而实现研究手段的可视化。在煤粉料仓下料系统上,通过线性反投影算法及图片累加技术,获得料仓出口管道截面的相对颗粒浓度分布图像和下料过程的二维流型图;对比分析了称重信号和ECT信号的时间序列曲线,并通过RSD统计方法定量描述煤粉下料的波动程度。结果表明,ECT研究与煤粉下料分区理论吻合良好,借助ECT可充分认识煤粉下料流型和气固作用特征。

Hopper discharge is one of the most important components in the entrained-flow gasification technology of pulverized coal. The safety and stabilization of hopper discharge are of great economic significance. In this paper, electrical capacitance tomography （ECT） was used to realize the visualization of pulverized coal discharge. The ECT images were reconstructed using linear back projection （LBP） algorithm and accumulated to obtain the relative particle concentration distribution and two-dimensional images of flow pattern. Furthermore, the weighing signal and ECT signal were analyzed and compared. Finally, statistical method of RSD was used to describe the fluctuation of hopper discharge. It showed that the research results of ECT agreed well with divisional discharging theory, which confirmed the feasibility of ECT application to the hopper discharge of pulverized coal.