Electrostatic induction measurement method and device for local particle velocity in fluidized bed

Abstract

The invention discloses electrostatic induction measurement method and device for local particle velocity in a fluidized bed. The method comprises the following steps of: packing an insulating and isolating material on one end of a metal shield pipe to form an insulating and isolating block, uniformly arranging a plurality of electrodes in parallel in the insulating and isolating block on the same plane to form a first electrostatic induction electrode array and a second electrostatic induction electrode array, and respectively connecting all electrodes in the two electrode arrays by using conducting wires; producing two groups of electrostatic signals reflecting gas-solid flowing information when electrified particles pass through the two electrostatic induction electrode arrays; and amplifying the electrostatic signals by a front-end charge differential circuit, sending to a computer through a data acquisition card, analyzing the spectrum of the differential electrostatic signals inthe computer, and determining the peak frequency on the spectrum so as to further acquire the local particle velocity of a gas-solid two-phase flow. The electrostatic induction measurement device forlocal particle velocity in the fluidized bed comprises a measurement probe, a front-end charge differential amplifying circuit, the data acquisition card and the computer.

Description

technical field [0001] The invention belongs to the technical field of gas-solid two-phase flow measurement, and in particular relates to an electrostatic induction measurement method and device for local particle velocity in a fluidized bed. Background technique [0002] The size of the particle velocity in the CFB boiler not only affects the residence time and density distribution of the particles in the bed, but also directly affects the heat transfer intensity between the particles and the heating surface, and then affects the specific layout of the heating surface. At present, based on different measurement principles, people have researched and developed a variety of methods and devices to measure particle velocity in circulating fluidized beds, such as fiber optic probe method, impact force method, constant velocity sampling method, Doppler laser velocimetry (LDV ) and Particle Image Technology (PIV), etc. The optical fiber probe method can be used for particle veloc...

AI Technical Summary

Problems solved by technology

For the electrostatic correlation and spatial filtering method, an external annular or arc-shaped electrostatic induction array is mainly used. The annular electrostatic induction can only obtain the average velocity of particles on the pipe section, while the arc-shaped electrostatic induction array is placed outside the measuring pipe, and the obtained information can only be obtained. It reflects the local particle velocity near the pipe wall, but cannot reflect the particle velocity distribution information on the entire pipe section

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