SCR denitration system ammonia spraying quantity optimal control system and method based on intelligent feedforward signals

Abstract

The invention relates to an SCR (Selective Catalytic Reduction) denitration system ammonia spraying quantity optimal control system and method based on intelligent feedforward signals. The SCR denitration system ammonia spraying quantity optimal control system based on intelligent feedforward signals is characterized in that as input parameters of a denitration system can be easily influenced by the combustion state of a boiler and for adapting to the requirement of large range of depth change of conditions for a thermal power generating unit, the SCR denitration system ammonia spraying quantity optimal control system based on intelligent feedforward signals takes the historical data of a power plant as the basis, utilizes the idea of data modeling, takes adjustable parameters at the boiler side as input and NOX concentration at the outlet of a hearth as output, utilizes a Least Squares Support Vector Machine algorithm to construct a prediction model which can be used for constructing an intelligent feedforward controller in a ammonia spraying quantity control strategy, and takes dynamic matrix control (DMC) as a main controller and PID as an auxiliary controller to construct a cascade feedback control structure; during the operating process, the intelligent feedforward controller outputs feedforward control signals in real time according to changes of the parameters at the boiler side, quickly gives a response to change of conditions of the unit, and forms an SCR system ammonia spraying quantity optimal control strategy together with feedback control, and can realize quick accurate control of the ammonia spraying quantity.

Description

technical field [0001] The invention relates to an optimization control system and method for an SCR denitrification system of a thermal power unit based on an intelligent feedforward technology, and belongs to the field of thermal automatic control. Background technique [0002] The flue gas produced by coal-fired power plants is atmospheric NO x One of the important sources of pollution, in order to reduce NO x emissions, selective catalytic reduction (Selective Catalytic Reduction, SCR) flue gas denitrification system has been widely used in thermal power plants. With the continuous improvement of environmental protection requirements, in order to save the cost of ammonia injection while meeting the national emission standards, the optimal control of the SCR system has received extensive attention. [0003] The SCR denitrification system is closely coupled with the furnace combustion, and the state of the flue gas at the outlet of the furnace determines the flue gas par...

AI Technical Summary

Problems solved by technology

There is a lag in the detection of flue gas parameter signals at the inlet and outlet of the SCR system, and there is a large delay in the reaction process of the SCR reactor. Traditional PID control can not get satisfactory control effect

Excessive ammonia injection will lead to increased ammonia escape, causing scaling and corrosion of the air preheater, and too little ammonia injection will cause NO at the outlet x Emissions do not meet national emission requirements

[0004] Therefore, when the working condition changes, only rely on the feedback control to realize the outlet NO x It is very difficult to accurately and quickly control the concentration, and there is no system or method to effectively solve this problem in the prior art

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