基于电容层析成像的生物质与煤粉混燃过程参数检测研究

Parameter mesurement system of gas/biomass/coal three-phase flow will be studied based on electrical capacitance tomography (ECT) technique.The research contents are as follows:(1)Based on the three-dimensional optimization design of geometry characteristic and spatial array for capacitance sensor,combined-electrode exciting-measuring strategy will be studied in order to increase projection data and enhance the homogenization of sensitivity field.Then,image reconstruction algorithm based on updated sensitivity matrix is to be studied.At last,to describe the media distribution more accuarately,capacitance normalized models are to be investigeted deeply.Through all the above researches,reconstructed images with higher accuracy can be obtained.(2)The dynamical response characteristics of gas/biomass/coal three-phase flow and the extraction of feature parameters of gas/biomass/coal three-phase flow will be studied extensively.(3)In-depth researches of correlation velocity measurement technique and its physical interpretation using ECT system will be carried out so as to enhance its measurement precision.Based on all the above researches,image reconstruction algorithms which can be adaptable to the soft -filed effect can be developed.The parallel processing system framework will also be constructed to enhance the imaging speed and spatial resolution.And then,the identification of gas/biomass/coal three-phase flow regimes, estimation of phase hold-up and measurement of flow parameters can be realized,which will provide bases of theory and engineering design for the development of new multiphase flow measurement devices.

本项目旨在设计基于电容层析成像技术的空气/生物质/煤粉三相流参数测量系统。项目主要内容：（1）在对电容阵列传感器进行"几何特性"及"空间阵列"三维优化设计基础上，研究组合电极激励测量策略，以期增加投影数据及提高灵敏场分布的均匀性；其次，研究基于灵敏度矩阵更新的图像重建算法；最后对电容归一化模型进行深入研究，以更好地描述介质分布。通过上述工作，提高重建图像精度；（2）探究空气/生物质/煤粉三相流动态响应特性及特征参数的提取；（3）结合电容层析成像系统对相关测速技术进行深入研究，探究相关流速的物理意义，提高其测量精度。基于上述研究，开发适应'软场'特性的图像重建算法，构建并行处理系统框架，提高实时成像速度与空间分辨率，实现空气/生物质/煤粉三相流流型识别、相含率估计及流动参数测量，为开发新型的多相流测量仪器提供理论与工程设计基础。

生物质与煤粉混合输送过程中，燃料在管道中分布不均匀，进而影响混烧过程的燃烧状况。针对这一问题，本项目研究了基于电容层析成像技术的空气/生物质/煤粉三相流可视化参数检测系统。主要完成了以下工作：（1）基于COMSOL软件对电容阵列传感器进行“几何特性”及“空间阵列”三维优化设计，开发了电容阵列传感器分析与优化设计软件包，可进行传感器二维/三维建模及敏感场分析等功能；（2）深入研究了基于‘软场’特性的电容层析成像图像重建算法，分别研究了基于混合电容归一化模型、灵敏度更新策略、卡尔曼滤波、组合电极激励测量模式、压缩感知算法的图像重建算法，提高了重建图像精度；（3）研制了电容层析成像数据采集系统，构建了小型生物质煤粉混合输送实验装置，并进行了初步实验，反应了该技术的可行性，可实现空气/生物质/煤粉三相流流型识别及相含率测量。