Ship multi-stage SCR series system and control method thereof

Abstract

The invention provides a ship multi-stage SCR series system and a control method thereof. The ship multi-stage SCR series system comprises SCRs, heat exchangers, an air heating closed system and a control system, wherein the SCRs are connected in series; the heat exchangers are arranged in front of inlets of the SCRs; the air heating closed system heats waste gas in each heat exchanger through airflow output by a heating system fan, and then the air flow flows back to the heating system fan; the control system controls the heat exchangers and the air heating closed system through a controller. According to the system, a common ship SCR is decomposed into the SCRs connected in series, the reactors eliminate the inconvenience that the large single reactor is arranged in a limited space in aship engine room in a certain degree, and arrangement and installation are facilitated. Besides, catalysts suitable for different positions are used in the reactors in different reaction sections, meanwhile, the NOx conversion efficiency is improved, and the service life of the catalysts are improved; and the maintenance cost is reduced.

Description

technical field [0001] The present disclosure relates to the technical field of ship air pollution treatment, in particular to a ship multi-stage SCR series system and a control method thereof for after-treatment of ship diesel engine exhaust. Background technique [0002] The vast majority of ships in the world use diesel engines as propulsion devices, which is determined by the thermal efficiency and reliability of diesel engines. Nitrogen oxides (NOx) in exhaust emissions from marine diesel engines x ) harm to the environment is gradually recognized by people. With the International Maritime Organization on marine diesel NO x As emission limits become increasingly stringent, Selective Catalytic Reduction (SCR) is gradually applied to ships. It is the NO in the exhaust gas x Under the catalytic action of the catalyst in the SCR reactor and NH 3 A reduction reaction occurs to form N 2 , so as to achieve the purpose of exhaust gas treatment. This technology is sensiti...

AI Technical Summary

Problems solved by technology

Due to the special working conditions of the main engine of the ship, the temperature of the exhaust gas is not too high, and the temperature is further reduced after passing through the exhaust gas turbine. If the position of the reactor is far from the exhaust side of the engine, it is more difficult for the exhaust gas temperature to reach the temperature of efficient reaction.

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