Control system and method for realizing uniform distribution of pulverized coal in direct-blowing pulverizing system

Abstract

The invention discloses a control system and a method thereof for realizing uniform pulverized coal distribution for a direct firing pulverizing system. The method comprises the following steps: measuring in real time to obtain pulverized coal flow rate and pulverized coal concentration in each pulverized coal conveying pipe; according to an equation that pulverized coal mass flow rate is equal to the pulverized coal concentration multiplied by the pulverized coal flow rate multiplied by the cross section area of each pulverized coal conveying pipe, calculating to obtain the pulverized coal mass flow rate in each pulverized coal conveying pipe; adjusting the openness of a throttling valve in each pulverized coal conveying pipe, so that the pulverized coal flow rate deviation among each group of pulverized coal conveying pipes is smaller than plus or minus 5 percent; adjusting the angle of a pulverized coal concentration adjusting plate in each coal mill pulverized coal distributor, so that the pulverized coal mass flow rate among the pulverized coal conveying pipes is smaller than plus or minus 10 percent. By adopting the control system and method, direct on-line monitoring on the pulverized coal concentration and the pulverized coal flow rate is realized, so that the pulverized coal concentration and the pulverized coal flow rate are both controlled to be within effective deviation ranges, and thus the effect of uniform pulverized coal distribution for the direct firing pulverizing system is realized.

Description

technical field [0001] The invention relates to the field of combustion control of pulverized coal boilers in large-scale coal-fired power plants, in particular to a control system and method for realizing uniform distribution of pulverized coal in a direct-blown pulverizing system. Background technique [0002] The coal pulverizers of pulverized coal boilers in large-scale coal-fired power plants generally use a direct blowing pulverization system to provide pulverized coal for the burners. The number of burners in each group corresponding to each coal pulverizer is 4 to 8. According to boiler design codes and standards, the deviation of pulverized coal mass flow distribution between each group of burners should be less than ±10%. The main factors that determine the distribution deviation of pulverized coal are the deviation of flow resistance between pulverized coal conveying pipes, the deviation of pulverized coal concentration, the fineness of pulverized coal and the rat...

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is to solve the problem that the existing direct-blowing pulverizing system cannot realize online measurement and adjustment of the mass flow rate of pulverized coal, so that there is a large deviation in the distribution of pulverized coal flow

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