1、 Nuclear Power Engineering 24 6 ( ) 2 0 0 3 12 Vol. 24. No. 6S2 Dec. 2 0 0 3 0258-0926(2003)06S2-0105-04 200030 - 0.2 0.8 - O459 A 1 1 - 2 3 2 2.1 0.04 60 m 3 /h 0.2 8 m 3 /h 0.1 0.15MPa ( ) 5m 2.2 1 4 2003-09-12 2003-12-20 Vol. 24. No. 6S2. 2003 106 4 1 3 2 4 1 3 2 4 2 4 1 Fig. 1 Schematic Diagram
2、of Charge and Discharge Method against Parasitic Capacitance Interference 2 Fig. 2 Scheme of Detector Cross-section 3 54 3 3 Fig. 3 Collection of Calibration Curves (QCV) N V a w m w V V V V V N - - = (1) V w V a V m 95% 14.5 0.2 0.8 =1.55N V(2) 4 4.1 4 7 ( ) - 107 4 Fig. 4 Void Fraction Time Series
3、 of Typical Stratified Flow 5 Fig. 5 Void Fraction Time Series of Typical Plug Flow 6 Fig. 6 Void Fraction Time Series of Typical Wavy Flow 7 Fig. 7 Void Fraction Time Series of Typical Wavy Flow with Dispersed Droplet - - 4.2 FFT FFT (1) 0.01 13Hz (2) (3) (4) 4.3 Vol. 24. No. 6S2. 2003 108 c- 14 2
4、Jc-c 100% 22 3 3 Jc-c 95% , 3 5 (1) 0.2 0.8 (2) - 1 Geraets J J M. A Capacitance Sensor For Two-Phase Void Fraction Measurement and Flow Pattern Identifica- tionJ. Int J Multiphase Flow, 1988, 14(3): 305 320. 2 Jones O C, Zuber N. The Interrelation Between Void Fraction Fluctuation and Flow Patterns
5、 in Two-Phase FlowJ. Int J Multiphase Flow, 1975, 2: 273 306. 3 Dsa P K. Electrical Impedance Method for Flow Regime Identification in Vertical Upwards Gas-liquid Two-phase FlowJ. Meas Sci Technol, 1993: 1457 1463. 4 . J. 1997: 28 32. Void Fraction Measurements in Gas-Liquid Flows Using Capacitance
6、Sensors and Flow Pattern Identification CHEN Hong KUANG Bo YANG Yang XU Ji-jun Department of Nuclear Science and System Engineering Shanghai Jiaotong University 200030 China Abstract Measurement techniques of the void fraction are always one of the key factors among two-phase flow survey. The author
7、 completes the design of the senor and the calibration measurement. The calibration curve is obtained in the void fraction range between 0.2 and 0.8. The results show that the void sensor is with excellent sensitivity and linear output also. The acquired typical void fraction signal is presented and
8、 qualitative discussion to the dynamic process and mechanism of flow is hence delivered. Meanwhile, with the introduction of mode recognition theory, flow patterns are off-line recognized through dynamical clustering algorithm. It can be expected to offer a practical and convenient means to the dynamical monitoring, controlling and fault diagnosis of the equipment in which two-phase flow exists. Key words Air-water two-phase flow Void fraction Capacitance void sensor Calibration Identification (1976 ) (1968 ) (1977 ) ( )
