System for increasing inlet temperature of SCR denitration reactor by utilizing flue gas recirculation

Abstract

The invention discloses a system for increasing the inlet temperature of an SCR denitration reactor by utilizing flue gas recirculation. The system comprises an original smoke device, a flue gas deacidifying and detoxifying unit, a bag dust collector, an SCR denitration unit, an induced draft fan and a flue gas recirculating pipeline which are sequentially connected by flues, wherein the flue gasrecirculating pipeline is provided with a smoke inlet end and a smoke outlet end; the smoke inlet end is connected to an outlet flue of the induced draft fan, or is connected to an outlet flue of thebag dust collector; the smoke outlet end is connected with an upstream flue of the bag dust collector. According to the system disclosed by the invention, by arranging the flue gas recirculating pipeline, waste heat flue gas from the outlet flue of the bag dust collector or the outlet flue of the induced draft fan is brought back to the upstream of the bag dust collector and the waste heat flue gas in the system is fully utilized, so that the inlet temperature of the SCR denitration unit is increased, heating energy of input flue gas of the SCR denitration unit is reduced, and operating conditions of the SCR denitration unit are ensured; in addition, the smoke exhausting amount of a chimney is overall reduced, and the whole system achieves the effect of economical and environment-friendlyoperation.

Description

technical field [0001] The invention relates to the field of environmental protection equipment, in particular to a system for increasing the inlet temperature of an SCR denitrification reactor by utilizing flue gas recirculation. Background technique [0002] At present, in the field of environmental protection, flue gas purification generally uses deacidification, detoxification, and dust removal processes in sequence to realize the pre-treatment of the source flue gas. Before the flue gas enters the SCR denitrification reactor, there are many places that need to use wind sources, such as The fly ash collected in the bag filter contains part of the deacidification agent that has not yet fully reacted in the deacidification reactor. In order to reduce the amount of deacidification agent used and improve the use efficiency of the deacidification agent, fly ash recycling is usually adopted. The air intake of the fluidization fan for fly ash circulation can ensure that the fly...

AI Technical Summary

Problems solved by technology

Due to the introduction of normal temperature air, the amount of flue gas increases, and the introduction of flue humidification and normal temperature water, the temperature of the flue gas at the outlet of the dust collector is greatly reduced, which cannot meet the SCR denitrification reactor catalytic reduction SCR reaction temperature requirements, such as 150~ 250°C, it is necessary to heat the flue gas to meet the corresponding temperature requirements

The existing flue gas treatment system has problems such as the excessive heat required to reach the SCR denitrification reactor, and the increase in system flue gas emissions.

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