Collaborative optimization method for coal-fired power plant boiler system and denitrification system operation

Abstract

The invention provides a coal-fired power plant boiler system and denitration system operation collaborative optimization method. The method comprises the following steps: the operation of a powder preparation system is optimized and adjusted; the operation of a combustion system is optimized and adjusted; the operation of a denitration system is optimized and adjusted; the coal-fired boiler NOx emission control and the SCR denitration system ammonia escape control are coupled for optimization and adjustment; an optimal operation oxygen quantity range of a coal-fired boiler under different loads and an optimal openness range of a burnt wind nozzle in the optimal oxygen quantity operation range are determined by combining the reductive atmosphere distribution characteristics in a near wall area of a hearth water cooling wall and the denitration ammonia escape conditions; and an optimal denitration efficiency range of the denitration system under different loads is determined. The three system operation collaborative optimization methods, provided by the invention, see the boiler system and the denitration system as a large system; the mutual correlation and influence among the three systems are decoupled from the angle of the large system; and the most economical and safest operation mode of the large system is obtained through optimization.

Description

technical field [0001] The invention belongs to the technical field of electric power production technology, and in particular relates to a coal-fired power plant boiler combustion, pulverizing system and denitrification system operation synergistic optimization method. Background technique [0002] The operation of coal-fired generating units in my country has the characteristics of "changeable coal quality, participation in peak regulation, wide load range, and high emission requirements". The multi-coal and wide-load operation mode not only affects the performance indicators of the unit, but also brings many problems to the safe and stable operation of the equipment. After installing the SCR flue gas denitrification device, these problems are more prominent. [0003] Although SCR flue gas denitrification technology has been widely used abroad, it is still in its infancy in China. The flue gas denitrification projects that have been built and are under construction are al...

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Problems solved by technology

[0017] Technical problem: The present invention provides a method for synergistic optimization of coal-fired boiler pulverization system, combustion system and denitrification system to overcome the problems in the prior art due to the flue gas flow field and components at the outlet of the boiler system (exit of the economizer) The mismatch between the concentration field and the rectification and diversion device of the denitrification system and the structure design of the reactor, and the mismatch between the distribution of ammonia injection in the denitrification system and the distribution of the flow field and component concentration field in the flue lead to the problem of excessive local ammonia escape at the denitrification outlet. Low-oxygen operation of the boiler caused by the mismatch between the NOx emission control of the boiler system and the performance of the denitrification system, high temperature corrosion of the water wall caused by excessive burn-out air volume, and excessive ammonia injection caused by the asynchronous operation status of the boiler system and the denitrification system question

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