基于ECT/EMT双模成像的气/液/固三相流过程参数表征方法

Gas-Liquid-Solid three-phase fluidization technique plays an important role in oil, chemical, metallurgical, power, food industries, due to its capability of dealing with massive particles and high efficiency in heat and mass transfer. The online measurement technique that capable of monitoring the fluid mechanics and behaviors is a critical factor for the multiphase flow researches and the reliable and efficient industrial production. Electrical tomography has advantages of non-invasive, non-intrusive, non-radiation and real-time flow visualization; however, it is still not capable of three phase characterization. The development of the electrical capacitance tomography (ECT) and electromagnetic tomography (EMT) dual modality imaging technique offers a novel idea. In most cases, the electromagnetic parameters of the three-phase materials differ from each other. The ECT/EMT dual modality technique could provide the capacitance and mutual inductance measurements, which describes the materials from different views. By applying data fusion to the multiple source data, the uncertainty of the reconstruct images of the investigated flow field can be reduced, which provide a possible solution to the Gas-Liquid-Solid three-phase flow measurement and characterization. The research will include the measuring and imaging principles of the ECT/EMT dual modality system, the development of digital data acquisition system, and the implementation of real-time dual modal measurements and image reconstructions of the Gas-Liquid-Solid three-phase flow in a synchronous manner. The research goal is to develop a novel process tomography method, and provide a solid foundation for the study on Gas-Liquid-Solid three-phase flow mechanics and multiphase flow measurement instrumentation.

气液固三相流态化技术具有高效传热、传质与处理大量颗粒的能力，在石油、化工、冶金、电力、食品等工业领域应用广泛；其流体力学行为异常复杂，相关参数的在线检测对科研及工业生产的安全、高效运行至关重要。电学成像方法具有非侵入、对流场无扰、无辐射和实时可视化的特点；然而，单模态电学成像并不具备三相识别能力。研究电容/电磁双模态层析成像是一种创新思路，利用气液固三相在电磁特性上的显著差异，以电容、电磁两种模态数据提升测量信息的维度，通过多传感器数据融合降低对流场的不确定性描述，为气/液/固三相流过程参数表征提供一种解决思路。本项目拟研究ECT/EMT双模成像的检测及成像机理，在此基础上开发双模成像算法，构建数字化硬件系统，实现对气液固的双模态同步测量和图像重建。本课题的成果将形成一种新的过程成像方法，为气液固三相流过程参数表征和多相流测试仪器开发奠定理论和工程基础。

气/液/固多相流动广泛存在于各种工业过程，如化工中的流态化过程、矿冶中的长距离油气管道输运过程等。多相流动参数的在线监测对相关工业过程的安全、稳定和高效运行起到至关重要的作用。本课题研究采用电容、电阻、电磁不同电学成像模态提升测量信息的维度，以实现对气/液/固三相流过程参数的表征。为此，结合Maxwell电磁场理论研究ECT/EMT双模成像的检测机理，以此为基础进行多模态图像重建算法的研究；采用CFD和电磁场联合仿真获取气/液/固三相流动模型数据，使用生成对抗网络的回归模型，结合ECT/EMT测量信息重建电学参数（介电常数、电导率和磁导率）分布，并通过有效介质近似模型计算气/液/固三相含率。本课题的成果为拓展电学过程成像方法的应用范围，提升对气/液/固多相流及其他复杂流动过程的非侵入检测能力、推进电学工业过程成像仪器的研发奠定理论和工程基础。