Automatic control method and system of thermal-power-unit SCR denitration ammonia spraying

Abstract

The invention discloses an automatic control method of thermal-power-unit SCR denitration ammonia spraying. The automatic control method includes the steps that the smoke flow and SCR-inlet-nitric-oxide concentration are obtained; the smoke flow is multiplied by the SCR-inlet-nitric-oxide concentration, and the basic-nitric-oxide content in smoke is obtained; the basic-nitric-oxide content is multiplied by the set denitration efficiency, and the basic-liquid-ammonia demanded quantity is obtained; the denitration-outlet-nitric-oxide content is obtained, the denitration-outlet-nitric-oxide content is compared with a denitration-outlet-nitric-oxide set value, an initial correction factor is obtained, a final correction factor is obtained in cooperation with further correction, and the liquid-ammonia demanded quantity is corrected. As the denitration-outlet-nitric-oxide set value is introduced, the denitration-outlet-nitric-oxide concentration serves as a final control target, the control target is specific, physical inspection and operation intervention intensity of operational persons are reduced, and the operational persons are liberated out of busy working. The invention also discloses an automatic control system of thermal-power-unit SCR denitration ammonia spraying.

Description

Technical field [0001] The invention relates to the technical field of thermal power units, more specifically, to an automatic control method for SCR denitration and ammonia injection of thermal power units, and also to an automatic control system for SCR denitration and ammonia injection of thermal power units. Background technique [0002] At present, most of the newly-built large-scale thermal power generating units in my country adopt the SCR (Selective Catalytic Reduction) method. The SCR method generally sprays reducing agents such as ammonia into the flue gas, and uses a catalyst to remove the NO in the flue gas. X Convert to N 2 And H 2 O. [0003] The classic SCR flue gas denitration control system uses NH 3 / NO X The principle that the molar ratio is approximately equal to 1, using flue gas inlet NO X The product of the concentration and the flue gas flow yields the basic NO X The content is the NO at the entrance of denitration X Total, multiplied by NH 3 / NO X The molar ...

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Problems solved by technology

[0005] In view of this, the first object of the present invention is to provide an automatic control method for SCR denitrification and ammonia spraying of thermal power units, which can effectively solve the problem that operators need to go through complex monitoring and operations to make the concentration of nitrogen oxides at the desulfurization outlet reach the standard. problem, the second purpose of the present invention is to provide an automatic control system for thermal power unit SCR denitrification ammonia injection

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