Method for monitoring distribution of pulverized coal in low-NOx tangential coal-fired boiler

Abstract

The invention discloses a method for monitoring distribution of pulverized coal in a low-NOx tangential coal-fired boiler. The method includes the steps that under the cold state condition that the boiler is not ignited, a resistance characteristic test is conducted on secondary air baffles, and the resistance characteristic of the baffles and the resistance characteristic of a hearth are obtained; the air speed, generated during heat-state operation of the boiler, of secondary air nozzles is computed according to the resistance characteristics; and the excess air coefficients of different combustion segments in the boiler are computed, and the distribution state of pulverized coal in the boiler is obtained. The method has the beneficial effects that the information of the excess air coefficients of all the combustion segments in the boiler can be provided for operators, so that the operators can confirm the air classification intensity of the main combustion region, and the method is especially suitable for the low-NOx tangential coal-field boiler adopting a direct-blowing type pulverizing system.

Description

technical field [0001] The invention relates to the technical field of monitoring air powder distribution in a furnace, in particular to a method for monitoring the distribution of air powder in a low NOx tangential coal-fired boiler furnace. Background technique [0002] With the improvement of environmental protection requirements, the control of nitrogen oxides (NOx) emissions in thermal power plants is becoming more and more stringent; the combination of low NOx combustion technology in the furnace and post-combustion NOx control technology is the best way to remove nitrogen oxides in flue gas Effective and most economical way; in recent years, power plant boilers have undergone large-scale low-NOx combustion technology transformation, and installed Selective Catalytic Reduction (SCR: Selective Catalytic Reduction) equipment in the tail flue of the boiler to synergistically remove nitrogen in the flue gas At present, this denitrification method has successfully controlle...

AI Technical Summary

Problems solved by technology

[0006] At present, for tangentially fired boilers using direct-blown pulverizing systems, the monitoring and adjustment of the pulverized coal nozzle powder supply is through the output of the coal feeder; however, there are a large number of air nozzles and the measurement conditions are harsh, and the air supplied by these nozzles is only The measurement of the air flow has not been realized through the adjustment of the baffle. Therefore, the operator cannot obtain the information of the excess air coefficient of each combustion zone in the furnace; The adjustment of the air nozzle flow rate is very blind, which is the main reason why some low NOx pulverized coal combustion systems use unreasonable air classification intensity to cause abnormal boiler operating parameters

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