Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)

The Korean Society of Mechanical Engineers (대한기계학회)
권호 표지
DOI QR코드

DOI QR Code

Development of an Electrical Capacitance Tomography Code for Analysis of Two-Phase Flow in the Rectangular Pipe

사각관 이상유동 분석을 위한 전기적 캐패시턴스 토모그라피 코드 개발

  • 이경황 (한동대학교 대학원 기계제어시스템공학부) ;
  • 이재영 (한동대학교 기계제어시스템공학부)
  • Published : 2005.01.01
Download PDF
⟨ Previous Next ⟩

Abstract

A computer code for Electrical Capacitance Tomography (ECT) is developed to sense the cross sectional phase distribution of two-phase flow in the rectangular pipe in which the tomography sensor furnished by the insulated wall, electrodes, and electric field screen. The computer code had two steps for the image reconstruction. In the forward projection step, the sensitivity matrix was constructed based on the electric field calculated by the finite difference method. In the backward projection step, the sensitivity matrix and the measured capacitances were used to reconstruct the cross sectional image. Several algorithms including LBP, TR, ITR, and PLI were employed to find the proper one for the two-phase flow analysis. Since the dielectric constant of the water in two-phase flow is sensitive to the thermal parameter such as, temperature and pressure, the developed code was evaluated to find their accuracy, speed of calculation, and sensitivity to the variation of the dielectric constant. It was found that the iterative methods are superior to the direct methods for the image reconstruction, and the PLI method was the best in the variation of the dielectric constants.

Keywords

References

  1. Lee, J.Y., Kim, N.S. and Ishii, M., 2003, 'An Instantaneous Flow Regime Identification Using Probability Distribution Function and Feed Forward Neural Network,' Proc. 10th Int. Topical Meeting on Nuclear Reactor Thermal Hydraulics, Seoul, A00309
  2. Williams, R.A. and Beck, M.S., 1995, 'Process Tomography, Principles, Techniques & Applications,' Butterworth-Heinemann Ltd.
  3. Park, M.C. and Lee, J.Y., 'Development of Capacitive Probe for Local Flow Parameter of Two Phase Flow' KNS spring meeting, 2004, Gyung Ju, Korea
  4. Huang, S.M., Xie, C.G., Thorn, R., Snowden, D. and Beck, M.S., 1992, 'Design of Sensor Electronics for Electrical Capacitance Tomography,' lEE proc. G, Vol. 139, pp. 83-88 https://doi.org/10.1049/ip-g-2.1992.0014
  5. Yang, W.Q. and York, T.A., 1999, 'New A.C. Based Capacitance Tomography System,' IEE Sci. Meas. Technol. Vol. 146, pp. 47-53 https://doi.org/10.1049/ip-smt:19990008
  6. Xie, C.G., Huang, S.M., Hoyle, B.S., Thorn, R., Lenn, C., Snowden, D. and Beck, M.S., 1992, 'Electrical Capacitance Tomography for Flow Imaging: System Model for Development of Image Reconstruction Algorithms and Design of Primary Sensors,' IEE Proc. G, Vol. 139, pp. 89-98 https://doi.org/10.1049/ip-g-2.1992.0015
  7. Mwamblea, A.J., Isaksen and Johansen, G.A., 1997, 'The Use of Entropic Thresholding Methods in Reconstruction of Capacitance Tomography Data,' Chem. Eng. Sci. Vol. 52, pp. 2149-2159 https://doi.org/10.1016/S0009-2509(97)00041-9
  8. Hammer, E.A. and Johansen, G.A., 1997, 'Process Tomography in the Oil Industry-State of the Art and Future Possibilities,' Meas. Control. Vol. 30, pp. 212-216
  9. Peng, L.H., Merkus, H. and Scarlett, B., 2000, 'Using Regularization Methods for Image Reconstruction of Electrical Capacitance Tomography,' Part. Part. Syst. Charact., Vol. 17, pp. 96-104 https://doi.org/10.1002/1521-4117(200010)17:3<96::AID-PPSC96>3.0.CO;2-8
  10. Lionheart, W.R.B., 2001, 'Reconstruction Algorithms for Permittivity and Conductivity Imaging,' Prc. 2nd world congr. On Industrial Process Tomography (Hannover, 2001), pp. 4-11
  11. Yang, W.Q., Spink, D.M., York, T.A. and McCann, H., 1999. 'An Image-Reconstruction Algorithm Based on Landweber's Iteration Method for Electrical Capaictance Tomography,' Meas. Sci. Technol., Vol. 14, pp. 1065-1069 https://doi.org/10.1088/0957-0233/10/11/315
  12. Yan, H., Liu, L.J. Xu, H. and Shao F.Q., 2001, 'Image Reconstruction in Electrical Capacitance Tomography Using Multiple Linear Regression and Regulaization,' Meas. Sci. Technol., Vol. 12, pp. 575-581 https://doi.org/10.1088/0957-0233/12/5/304
  13. Jinchuang, Z., Wenli, F., Li, T. and Shi, W, 2002, 'An Image Reconstruction Algorithm Based on a Revised Regularization Method for Electrical Capacitance Tomography,' Meas. Sci. Technol., Vol. 13, pp. 638-640 https://doi.org/10.1088/0957-0233/13/4/329
  14. Hanssen, P.C., 1998, 'Rank-Deficient and Discrete III-posed Problems,' Philadelphia, PA: SIAM
  15. Yang, W.Q. and Peng, L., 2003, 'Image Reconstruction Algorithms for Electrical Capacitance Tomography,' Meas. Sci. Technol., Vol. 14, pp. R1-R13 https://doi.org/10.1088/0957-0233/14/1/201
  16. Yang, W.Q. and Liu, S., 1999, 'Electrical Capacitance Tomography with a Square Sensor,' 1st world congress on Industrial process tomography., Session H1: Hardware, pp. 313-317