层析成像在冰水两相流参数测量中的应用

Application of electrical resistance tomography to ice-water two-phase flow parameter measurement

提出将电阻层析成像(ERT)技术应用于冰水两相流相含率、相分布等特征参数的测量,并设计了ERT测量系统,研究了基于图像的相含率计算方法。阐述了ERT系统的工作原理,提出了16电极ERT系统的设计方案。介绍了线性反投影图像重构算法(LBP);并结合数字图像处理技术,提出了截面相含率的计算方法。最后,通过一组实验验证了电阻层析成像技术应用于冰水两相流检测的可行性。实验结果表明:通过ERT系统可以获得管道内冰柱在水中的位置以及实时运动结果,直观反映冰水两相介质的相分布;另外,通过ERT系统可以近似地真实反映冰柱的相对大小,两次截面相含率测量误差分别为6%与2.8%。研究表明,ERT技术可以实现冰水两相流的实时在线监测,而且具有良好的测量准确度。

A method to measure ice-water two-phase flow was proposed by using an Electrical Resist- ance Tomography（ERT）. An ERT system was designed and the calculating method for phase frac- tions was explored based on imaging technology. Firstly, the principle of ERT system was intro- duced, and the design scheme for the ERT system with 16 electrod（s was proposed, then a Linear Back Projection （LBP） image reconstructed algorithm were given. Furthermore, the analyzing meth- ods for measured data of ERT system were presented and applied them to the identification of phase distribution and the estimation of phase fractions. Finally, several experiments were performed to ver- ify the applied feasibility of the ERT system to ice-water two-phase flow measurement. The experi- mental results show that the ERT system can be used to obtain the positions of ice column within a tube in water and their movement sates in real time and can reflect the phase distribution of ice-water two-phase media intuitively. The relative sizes of the ice column can be obtained by the ERT system and the error of phase fractions are 6% and 2.8%, respectively. The research results prove that the ERT system can monitor the transportation process of ice-water two-phase flow on-line with higher measuring accuracy.