Novel SNCR (selective non-catalytic reduction) and SCR (selective catalytic reduction) hybrid denitrification system

Abstract

The invention relates to the technical field of industrial smoke nitric oxide emission reduction and denitrification and relates to a novel SNCR (selective non-catalytic reduction) and SCR (selective catalytic reduction) hybrid denitrification system. The novel SNCR and SCR hybrid denitrification system comprises a preparation and storage module, a conveying circulating module, a metering and diluting module, an on-line NOX monitoring module, an automatic control module, a distribution module, a spraying module, a boiler and an SCR reactor. According to the novel SNCR and SCR hybrid denitrification system, an existing SNCR and SCR denitrification system is improved and united, so that full-automatic intelligent operation is realized; the automatic control module can accurately calculate a demand of a denitrification reducing agent by monitoring a nitride generation amount and other data in smoke gas on line and in real time according to the real-time change of a load of the boiler and feed back information to the metering and diluting module; the metering and diluting module can quickly adjust corresponding equipment to accurately provide the corresponding amount of the reducing agent to the distribution module and the spraying module; the reducing agent and smoke gas are sprayed in the boiler and a flue and are then mixed to enter the SCR reactor to implement denitrification reaction; therefore, the beneficial effects of high denitrification efficiency, high automation degree, low investment cost and good denitrification effect are achieved.

Description

technical field [0001] The invention relates to the technical field of flue gas nitrogen oxide emission reduction and denitrification, and relates to a novel SNCR and SCR mixed denitrification system. Background technique [0002] With nitrogen oxides NO X Emissions continue to increase, acid rain pollution has changed from sulfuric acid type to sulfuric acid and nitric acid compound type, and the urban atmospheric environment is still grim. With the development of my country's economy and the improvement of environmental standards, flue gas denitrification technology will be widely used in my country's thermal power, domestic waste incineration and cement industries. At present, the mainstream flue gas denitrification technologies mainly include selective catalytic reduction (SCR), selective non-catalytic reduction (SNCR), and low-nitrogen combustion technology. Among them, SCR technology is the most efficient, most widely used and most mature denitrification technology. ...

AI Technical Summary

Problems solved by technology

[0010] Existing SNCR and SCR denitrification systems generally need to use a pyrolysis device to pyrolyze urea or ammonia water into ammonia gas as a reducing agent. The ammonia gas is sprayed into the boiler or boiler flue through the injection module, which is prone to hidden dangers of ammonia gas escape, and it is common The optimal amount of reductant injection is not automatically and more accurately controlled, which does not correspond to the amount required for real-time denitrification reaction, resulting in excessive reductant causing waste, or too little denitrification effect is not very ideal. Usually, the SNCR denitrification of large boilers The denitrification efficiency of the system is below 40%

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