Pulverized coal flow online measuring device and measuring method

Abstract

The invention discloses a pulverized coal flow online measuring device and measuring method. The device is characterized in that a measuring pipe is connected to a primary air pipeline in series and is made of a ceramic material; the two ends of the measuring pipe are each provided with two sets of capacitance sensors; the capacitance sensors are 2n electrode plates annularly and evenly distributed on the outer wall of the measuring pipe, and the 2n electrode plates are n plate capacitors oppositely arranged in pairs; capacitance of the plate capacitors serves as an output signal of the measuring device. Interval measurement of the plate capacitors is adopted, measurement errors caused due to uneven spatial distribution of pulverized coal concentration and speed are effectively reduced, and measuring precision is improved. By means of the measuring device, adjustment can be carried out in time according to data of pulverized coal flow online measuring, so that the problem that burning of the primary air pipeline, overheat of a heated face, slagging, thermal deviation and the like are caused due to pipeline pulverized coal accumulation, pulverized coal pipeline blocking and unbalance of pulverized coal distribution is avoided, and boiler combustion is optimized.

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.

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