Feed-forward automatic control method for ultralow emission of nitrogen oxide based on SCR (Selective Catalytic Reduction) method

Abstract

The invention relates to an SCR method for removing nitrogen oxides NOX. A feedforward automatic control method for ultralow emission of nitrogen oxide based on an SCR method comprises the steps that the real-time concentration C1 and the real-time flow Q1 of nitrogen oxide NOx at an inlet of a denitration reactor are obtained, the real-time concentration C2 and the real-time flow Q2 of nitrogen oxide NOx at an outlet of the denitration reactor are obtained, the proportion of escape ammonia gas at the outlet of the denitration reactor in the actual value of the given amount of ammonia water is obtained, and the actual value of the given amount of ammonia water is calculated; the flow Q4 of the ammonia water nozzle at the inlet of the denitration reactor is obtained, and in the initial state, Q4 is the theoretical ammonia water flow for complete reaction of the real-time concentration C1 of the NOx at the inlet of the denitration reactor and the real-time flow Q1. After the new feedforward control method is adopted, the problem that effective tracking cannot be realized by automatic control due to the fact that a flue is too long and data acquisition is not timely in a traditional control method is solved.

Description

technical field [0001] The invention relates to the removal of nitrogen oxide NO by SCR method X . Background technique [0002] Realization of Nitrogen Oxide NO by SCR Method X The principle of ultra-low emissions is to use the ammonia sprayed water to form ammonia after passing through the evaporator, and the nitrogen oxides NO in the industrial tail gas in the denitrification reactor X A catalytic reduction reaction occurs. At this time, it is necessary to continuously adjust the given amount of ammonia water through the ammonia water regulating valve so that the nitrogen oxides NO in the tail gas X Fully respond to achieve environmental protection emission targets. At the same time, it is necessary to ensure the proper amount of ammonia water to avoid damage to the rear flue of subsequent equipment caused by waste and exhaust ammonia escape. The artificially given amount of ammonia water needs to be constantly adjusted according to changes in working conditions, suc...

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Problems solved by technology

[0007] It needs to be very accurate and conforms to the actual chemical reaction mathematical model, and it also requires the operator to frequently adjust the control parameters, which is basically difficult to achieve

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