Preliminary evaluation of cryogenic two-phase flow imaging using electrical capacitance tomography. (September 2017)

• Record Type: Journal Article
• Authors: Xie, Huangjun; Yu, Liu; Zhou, Rui; Qiu, Limin; Zhang, Xiaobin
• Is Part Of: Cryogenics. Volume 86(2017)
• Page Start: 97
• Page End: 105
• Publication Date: 2017-09
• Subjects: Cryogenic -- Two-phase flow -- ECT -- FEM -- Void fraction; Low temperature engineering -- Periodicals; Low temperature research -- Periodicals; 536.56
• DOI: 10.1016/j.cryogenics.2017.07.008
• Languages: English
• ISSNs: 0011-2275

Abstract

Highlights: Eight-electrode ECT used for phase distribution of cryogenic flow is evaluated. Eight LN2 -VN2 cases are imaged with accepted quality. Inversion results of LN2 -VN2 and water-air are comparably good. Influences of measurement noise are considered. Abstract: The potential application of the 2-D eight-electrode electrical capacitance tomography (ECT) to the inversion imaging of the liquid nitrogen-vaporous nitrogen (LN2 -VN2 ) flow in the tube is theoretically evaluated. The phase distribution of the computational domain is obtained using the simultaneous iterative reconstruction technique with variable iterative step size. The detailed mathematical derivations for the calculations are presented. The calculated phase distribution for the two detached LN2 column case shows the comparable results with the water-air case, regardless of the much reduced dielectric permittivity of LN2 compared with water. The inversion images of total eight different LN2 -VN2 flow patterns are presented and quantitatively evaluated by calculating the relative void fraction error and the correlation coefficient. The results demonstrate that the developed reconstruction technique for ECT has the capacity to reconstruct the phase distribution of the complex LN2 -VN2 flow, while the accuracy of the inversion images is significantly influenced by the size of the discrete phase. The influence of the measurement noise on the image quality is also considered in the calculations.