Digitized combustion control and optimization method and system for pulverized coal boiler

Abstract

The invention discloses a digitized combustion control and optimization method and system for a pulverized coal boiler. The method includes the steps that pulverized coal flowing speed and pulverized coal concentration of all pulverized coal conveying pipes are adjusted in real time, so that the deviation of the pulverized coal flowing speed of all the pulverized coal conveying pipes is smaller than + / -5%, and the flow deviation of pulverize coal quality is smaller than + / -10%; according to the current secondary air amount, the pulverized coal input amount and air content of primary air of each pulverized coal combustor, the air-fuel ratio numerical value or the excess air coefficient of each combustor is obtained, and the deviation of the air-fuel ratios among all the pulverized coal combustors is smaller than + / -10% through adjusting secondary air adjusting valves of the pulverized coal combustors; according to the change trend of unburned carbon in flue dust, and the oxygen content and the carbon monoxide concentration in tail gas fume, the coal-conveying amount and secondary air amount are adjusted so that the air-fuel ratio or the excess air coefficient of each combustors can reach the optimal set value. Through distribution and leveling of pulverized coal and reasonable adjustment of the air-fuel ratios in the combustors, the combustion process of the pulverized coal boiler is controlled and optimized in a digitalized mode.

Description

technical field [0001] The invention relates to a pulverized coal boiler of a large coal-fired power plant, in particular to a method and system for digitalized combustion control and optimization of the pulverized coal boiler. Background technique [0002] The digital combustion control and optimization of pulverized coal boiler is an important technical way to realize energy saving and emission reduction in thermal power plants. For large pulverized coal boilers, whether the distribution of pulverized coal fuel during operation is uniform, and whether the primary and secondary air distribution is reasonable will directly affect the economy, safety and environmental protection level of unit operation. Due to the complexity of the pulverized coal combustion process in the boiler furnace, operators can only adjust the combustion according to their long-term accumulated operating experience. [0003] Nowadays, domestic large-scale thermal power generation units are generally ...

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Problems solved by technology

[0007] The technical problem to be solved by the present invention is to solve the problem that the combustion optimization control mode of the existing pulverized coal boiler cannot further improve the efficiency of pulverized coal combustion and reduce the emission concentration of nitrogen oxides

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