气固两相流测量的静电成像阵列传感器机理与成像关键技术研究

It has important theoretical and practical significance of the research on measurement of gas/solid two-phase flow parameters such as velocity, flow pattern, void fraction and flowrate, etc. For example, the online measurement of particle quality and distribution of the pulverized coal injection pipe inside can optimize the powder/gas mixing ratio, improve combustion efficiency and reduce pollution emissions. The accurate parameters measurement of gas/solid two-phase flow is always a difficult problem because of gas/solid two-phase flow is very complicated and influence factor is very much. In recent years, electrostatic method (particle flow generate electrostatic) is a new method of gas/ solid two-phase flow parameter measurement. The traditional ring or probe type electrostatic sensor is difficult to obtain the information of particle position and distribution in the cross section of the pipeline and it is unable to realize the flow pattern identification. However, the array type electrostatic imaging technology can potentially provide a good solution. The main research contents including: sensitive mechanism research of array sensor to charged particles (sensitive electrode material, structure, shape and size can affect the sensitivity of induction charge measurement，frequency response and the spatial filtering characteristics, etc.); high sensitive-weak-charge signal amplifying and imaging data acquisition hardware system.

气固两相流参数如流速、流型、分相含率和流量等的测量研究具有重要的理论与实际意义。例如，火电厂煤粉喷吹管内分布和颗粒品质的在线检测就可优化粉/气混合比，提高燃烧效率，减少污染排放等。气固两相流流动十分复杂，影响因数多，因此气固两相流参数的准确测量一直是个难题。静电法（颗粒流动产生静电）是近年来气固两相流参数测量的一种新方法，但环状或探针式静电传感器难以获得颗粒在管道截面的位置及分布信息，无法实现流型等参数测量，而阵列式静电成像技术却提供了一种潜在的较好解决方法。课题主要研究内容：阵列式传感器对颗粒荷电敏感机理研究（敏感电极材料、结构、形状、尺寸对感应电荷测量灵敏度、频响及空间滤波特性等的影响）；静电成像阵列传感器高灵敏微弱电荷信号获取放大实验研究。

气固两相流参数如流速、流型、分相含率和流量等的测量研究具有重要的理论与实际意义。例如，火电厂煤粉喷吹管内分布和颗粒品质的在线检测就可优化粉/气混合比，提高燃烧效率，减少污染排放等。气固两相流流动十分复杂，影响因数多，因此气固两相流参数的准确测量一直是个难题。静电法（颗粒流动产生静电）是近年来气固两相流参数测量的一种新方法，但环状或探针式静电传感器难以获得颗粒在管道截面的位置及分布信息，无法实现流型等参数测量，而阵列式静电成像技术却提供了一种潜在的较好解决方法。. 课题主要研究内容：1)阵列式传感器对颗粒荷电敏感机理的仿真与理论研究。在对敏感电极材料、结构、形状、尺寸对感应电荷测量灵敏度、频响及空间滤波特性等的影响进行深入研究基础上，建立了有关数学模型，进行了理论与仿真实验研究，并对静电成像阵列传感器进行了优化设计，发表了相关研究文章和申请了有关专利；2）静电成像阵列传感器微弱电荷信号获取放大电路的理论仿真与实验研究。对静电传感器电极感应拾取得到的微小电荷信号进行转换放大处理，是静电成像的又一关键技术。由于信号相当微弱，必须进行前置放大、滤波和整流处理，尤其对整个电路的信噪比、频带宽度等性能参数有很高要求，否则会直接影响到静电成像质量和精度。本课题对电路部分进行了仿真和实验研究，设计出了一种能满足使用要求的电路，进行了初步成像实验，获得了有应用价值的测试数据与结果。