An on-line measurement device and measurement method for pulverized coal flow

Abstract

The invention discloses an on-line measurement device and method for pulverized coal flow, which is characterized in that: a section of measuring tube is arranged in series on the primary air duct, the measuring tube is made of ceramic material, and two sets of measuring tubes are respectively installed at both ends of the measuring tube Capacitive sensor; the capacitive sensor is a circular uniform distribution of 2n electrode plates on the outer wall of the measuring tube, and the 2n electrode plates form n plate capacitors in pairs; the capacitance of the plate capacitor is used as the output signal of the measuring device. The present invention adopts the multi-plate electric capacitance interval measurement, which effectively reduces the measurement error caused by the uneven spatial distribution of the pulverized coal concentration and velocity, and improves the measurement accuracy; the device of the present invention can be used for timely adjustment according to the online measurement data of the pulverized coal flow , so as to avoid problems such as pipeline dust accumulation, pulverized coal plugging and unbalanced distribution of pulverized coal, such as primary air duct burnout, overheating of the heating surface, slagging and thermal deviation, etc., and optimize boiler combustion.

Description

technical field [0001] The invention relates to an on-line measurement device and method for pulverized coal flow, more specifically to a device and method for on-line measurement of pulverized coal flow for coal-fired boilers. Background technique [0002] In the actual operation of coal-fired power plants, due to the difference in resistance of the four primary air pipes at the outlet of the coal mill, problems such as pipe blockage of pulverized coal and uneven distribution of pulverized coal often occur. The uneven flow distribution of pulverized coal sprayed into the furnace will directly affect the combustion of the boiler, resulting in the deflection of the flame center of the furnace, the obvious difference in heat load, causing local over-temperature coking of the water-cooled wall, and large thermal deviation between the left and right of the superheater and reheater. , Seriously affecting the safety and economy of boiler operation. [0003] The unbalanced distrib...

AI Technical Summary

Problems solved by technology

In the actual sampling process, it is difficult to ensure constant velocity, which causes a large measurement error

At the same time, this method has a large workload and a long response time, and cannot achieve continuous online measurement

At present, the instrument that uses the capacitance method to measure the flow of pulverized coal does not take into account the measurement error caused by the uneven distribution and velocity of pulverized coal in the pipeline

Although electrical capacitance tomography can obtain information about the phase distribution of pulverized coal in the pipeline cross-section, the algorithm is complex, the resolution is low, and the measurement accuracy is not high due to inadaptability and soft field effects.

Images