Intelligent dynamic partition ammonia spraying control method and system

Abstract

The invention provides an intelligent dynamic partition ammonia spraying control method and system. The method comprises an intelligent total amount control method and an intelligent partition controlmethod. The invention further provides an ammonia spraying system using the method. The ammonia spraying system comprises a DCS system module, a PLC controller module and a big data analysis module.The DCS system module is connected with the PLC controller module through an LC card by adopting a MODBUS communication protocol, and the PLC controller module is connected with the big data analysismodule through a TCP / IP protocol. The ammonia spraying total amount of the denitration reactor can be effectively controlled, the ammonia spraying uniformity can be guaranteed according to the branchpipe adjusting valves, ammonia escape is effectively reduced, and the purpose of environment-friendly emission is achieved.

Description

technical field [0001] The invention relates to the technical field of flue gas denitrification in coal-fired power plants, in particular to an intelligent dynamic zoned ammonia injection control method and system. Background technique [0002] With the promulgation of a series of national policies and regulations, the emission of air pollutants from coal-fired power plants has been brought under strict supervision, and each power plant has successively carried out retrofits for ultra-low emission of flue gas. After ultra-low emission transformation, the NOx emission concentration of coal-fired power plants must be lower than 50mg / m 3 , to develop perfect denitrification technology for thermal power plants, and to reduce the discharge of pollutants from power plants as much as possible has become an imperative task for power plants in our country. [0003] At present, the most widely used denitrification technology at home and abroad is SCR (Selective Catalytic Reduction, S...

AI Technical Summary

Problems solved by technology

[0004] The total amount control method of ammonia injection usually adopts single-loop outlet NOx fixed value control strategy, fixed molar ratio control strategy, and cascade PID control strategy, which mainly adjusts the total amount control valve according to the deviation between the outlet NOx concentration and its set value. However, the NOx concentration at the outlet of the SCR reactor is often measured by single-point sampling or multi-point sampling after mixing. The measured value is not enough to represent the concentration at the SCR outlet. The characteristics of delay and large lag, the current control strategy has poor control effect

The uniformity of ammonia injection is mainly based on the manual adjustment of the manual control valve, which requires a large workload and takes a long time for each adjustment.

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