Void Fraction Measurement of Two-phase Flow with Microbubbles by Constant Electric Current Method
Void fraction in a core of light-water nuclear reactors has an influence on the fission reaction. Average bubble diameters, bubble diameter distributions and void fractions are important physical quantities in those fields. Therefore developments of real-time measurement systems of average void fraction have been required. Electric-void fraction measurement methods have been proposed as one of the real-time measurement methods in the nuclear power engineering. In addition, microbubbles are recently applied as tracer particles to Ultrasonic Doppler Methods which are used for velocity measurements. In this study, we evaluated performances of constant electric current method (CECM) for real-time measurements of void fraction in bubbly flow which is containing bubbles of several hundred μm. In this experiment, CECM was applied as one of electric-void fraction measurement methods. Air and water were used as working fluids. Microbubbles were generated with a bubble collapse methods using a Venturi tube. Voltage between measurement electrodes has been measured for gas-liquid two phase flow as inlet conditions. The gas-liquid two phase flow structure was observed by the high speed video camera. Average bubble diameters and bubble diameter distributions were estimated by image analysis of high speed camera images. A relation between inlet gas-liquid flow rates and the voltage ratio measured by CECM was confirmed in wide ranges of volume flow rates. The void fraction for bubbly flow with microbubbles was calculated by Maxwell’s theory. The present study suggested that real-time measurements of void fractions for bubbly flow with microbubbles by CECM were possible.
Void fraction measurement CECM Two-phase flow Microbubbles
Shin-ichiro Uesawa Akiko Kaneko Yasumichi Nomura Yutaka Abe
University of Tsukuba 1-1-1 Tennodai Tsukuba Ibaraki Japan
国际会议
上海
英文
1987-1998
2010-10-10（万方平台首次上网日期，不代表论文的发表时间）