The concentration measurement of biomass/pulverized coal/air three­phase flow based on electrostatic and capacitive method

Juan Zhang1; Hongli Hu1*; Jun Dong1; Xiao Zhang1; Tongmo Xu2

1. State Key Laboratory of Power Equipment and Electrical Insulation Xi’an Jiaotong University, Xi’an710049, China

2. State Key Laboratory of Power Engineering and Multi­phase Flow Xi’an Jiaotong University, Xi’an710049, China

ABSTRACT

A system for the phase concentration measurement of biomass/pulverized coal/air three­phase flow based on electrostatic sensor and capacitive sensor data fusion in pneumatic conveying fuel system at power stations is developed. Because electrostatic sensor is more sensitive to dilute pulverized coal, while capacitive sensor to biomass, they are used in the measurement of biomass concentration and pulverized coal concentration in biomass/pulverized coal/air three­phase flow. Flow regimes are identified by HHT of the electrostatic sensor output signal. Under the certain flow regime identified, the dual regression analysis method is applied to work out the biomass concentration and the pulverized coal concentration. The experiment result indicates that the system has high linearity up to 5%.

Keywords Three­phase flow; Concentration measurement; Capacitance sensor; Electrostatic sensor; Flow regime identification; Data fusion