Phase identification by a novel needle-contact capacitance probe in gas-liquid two-phase flows

Phase identification by a novel needle-contact capacitance probe in gas-liquid two-phase flows 1 2 corresp first-author Corresponding author. E-mail address: sfhuang@mail.tsinghua.edu.cn Corresponding author. E-mail address: sfhuang@mail.tsinghua.edu.cn sfhuang@mail.tsinghua.edu.cn 3 2 2 Department of Engineering Physics, Tsinghua University, Beijing 100084, China Department of Engineering Physics, Tsinghua University, Beijing 100084, China State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi′an 710049, China State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi′an 710049, China Beijing Aerospace Institute for Metrology and Measurement Technology, Beijing 100076, China Beijing Aerospace Institute for Metrology and Measurement Technology, Beijing 100076, China In this paper, we propose a novel probe to identify phases in any two-phase flows where one phase is conductive and the other nonconductive. We can further obtain many parameters such as void fraction, bubble velocity, and interfacial area concentration. Compared with the traditional probe, the novel probe has unique advantages that it is less dependent on water conductance or distance between the electrodes, and that the amplitude is bigger between high and low levels. Theoretical analyses showed that the measurement error became higher when water conductance decreases or distance increases, which is consistent with the theoretical analyses. Experimental results showed that the output signal kept constant with salt content of 0−5% and electrode distance of 0−30 mm in tap water. The level difference was up to 6.4 V, resulting in identifying two phases easily. Time traces of phase identification were completely consistent with the flow structures. Needle-contact capacitance probe Phase identification Flow structure References Fordham E J , Holmes A , Ramos R T , et al , Meas Sci Technol , 1999 , 10 : 1329 - 37 . Meas Sci Technol Fordham E J , Simonian S , Ramos R T , et al , Meas Sci Technol , 1999 , 10 : 1338 - 46 . Meas Sci Technol Fordham E J , Ramos R T , Holmes A , et al Meas Sci Technol , 1999 , 10 : 1347 - 52 . Meas Sci Technol Gopal M , Jepson W P . Int J Multiphase Flow , 1997 , 23 : 945 - 65 . Int J Multiphase Flow Angeli P , Hewitt G F . Int J Multiphase Flow , 2000 , 26 : 1117 - 40 . Int J Multiphase Flow Hibiki T , Ho Lee T , Young Lee J I . Chem Eng Sci , 2006 , 61 : 7979 - 90 . Chem Eng Sci Hazuku T , Takamasa T , Hibiki T . Int J Heat Mass Transfer , 2007 , 50 : 2986 - 95 . Int J Heat Mass Transfer Zheng D H , Che D F . Int J Multiphase Flow , 2006 , 32 : 1191 - 1218 . Int J Multiphase Flow Prasser H M , Bottger A , Zschau J . Flow Meas Instru , 1998 , 9 : 111 - 119 . Flow Meas Instru Prasser H M , Misawa M , Tiseanu I . Flow Meas Instru , 2005 , 16 : 73 - 83 . Flow Meas Instru Fagundes Netto J R , Fabre J , Peresson L . Int J Multiphase Flow , 1999 , 25 : 1129 - 60 . Int J Multiphase Flow Huang S F , Zhang X G , Wang D , et al . Meas Sci Technol , 2007 , 18 : 3784 - 94 . Meas Sci Technol Huang S F , Zhang X G , Wang D et al . Int J Multiphase Flow , 2008 , 34 : 809 - 18 . Int J Multiphase Flow Huang S F , Zhang B D , Lu J et al . Nucl Sci Techni , 2010 , 21 : 246 - 250 . Nucl Sci Techni 10.13538/j.1001-8042/nst.21.316-320 Support by the National Natural Science Foundation of China (No. 51006068). 2010-09-18 2010-10-20 2021-01-19 2010 Nuclear Science and Techniques 05 21