SCR (selective catalytic reduction)-based ship denitration system tail gas cyclic retreatment device

Abstract

The invention relates to an SCR (selective catalytic reduction)-based ship denitration system tail gas cyclic retreatment device. The SCR-based ship denitration system tail gas cyclic retreatment device comprises an internal combustion engine, an ammonia injecting grid and an SCR reactor; the gas discharge end of the SCR reactor is communicated with a discharge chimney through a main flue; a NOx concentration sensor and a chimney shield are arranged in the main flue sequentially from the gas inlet end to the gas outlet end; the SCR-based ship denitration system tail gas cyclic retreatment device also comprises a circulating bypass flue and a controller; the gas inlet end of the circulating bypass flue is communicated with the main flue between the NOx concentration sensor and the chimney shield; the gas discharge end of the circulating bypass flue is communicated with a tail gas pipeline; a circulating bypass valve is arranged on the flue at the gas inlet end of the circulating bypassflue; and the controller is connected with the ammonia injecting grid, the NOx concentration sensor, the chimney shield and the circulating bypass valve separately through pipelines. The SCR-based ship denitration system tail gas cyclic retreatment device has the following advantages: the denitration rate of the tail gas of the ship internal combustion engine is increased, the nitric oxide in thedischarged gas is reduced, and discharge of the treated gas not up to the standard is avoided.

Description

technical field [0001] The invention relates to a ship tail gas cycle denitrification reprocessing device, in particular to a tail gas cycle reprocessing device based on an SCR ship denitrification system. Background technique [0002] Nitrogen oxides in the exhaust of ships' internal combustion engines are one of the main air pollutants. With the continuous development of maritime transportation, the pollution of the current environment by ships' waste emissions is becoming more and more serious. According to the data provided by the International Maritime Organization, 30% of the world's annual emissions of nitrogen oxides come from ships at sea. Therefore, how to eliminate nitrogen oxides in ship exhaust is particularly important. [0003] At present, the most widely used is the SCR (Selective Catalytic Reduction) denitrification system (selective catalytic reduction technology). The SCR denitration method has no by-products, no secondary pollution, simple device struct...

AI Technical Summary

Problems solved by technology

The amount of ammonia gas introduced, the temperature in the SCR reactor, and the degree of contact between the mixed gas and the catalyst will directly affect the denitrification rate of the tail gas. When the reaction is incomplete, the content of nitrogen oxides in the treated tail gas does not reach the emission level. At this time, if the gas after the reaction is discharged directly, it will pollute the atmosphere with a lot of noise

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