Exhaust gas denitration device and method of controlling exhaust gas denitration device

Abstract

An exhaust gas denitration device for reduction of nitrogen oxides contained in engine exhaust gas discharged from a main engine mounted on a ship, the exhaust gas denitration device being provided with: an exhaust flow passage through which the engine exhaust gas discharged from the main engine flows; a reducing agent storage tank; a reducing agent spray nozzle; a denitration reactor including adenitration catalyst; a boiler exhaust gas conduit which guides boiler exhaust gas discharged from a boiler mounted on the ship to the upstream side of the denitration reactor in the exhaust flow passage; a boiler exhaust gas control valve which controls the flow of boiler exhaust gas in the boiler exhaust gas conduit; and a blower which blows the boiler exhaust gas flowing through the boiler exhaust gas conduit to the downstream side.

Description

technical field [0001] The invention relates to a waste gas denitrification device and a control method for the waste gas denitrification device. Background technique [0002] Affected by the tightening of environmental regulations in recent years, the reduction of nitrogen oxides (NOx) contained in the exhaust gas from the engine is also required in the marine two-stroke diesel engine used as the main engine of the ship. As a method for reducing NOx contained in engine exhaust gas, for example, a selective catalyst reduction method (SCR method) is conventionally known in which a reducing agent is injected into engine exhaust gas to reduce nitrogen oxide (NOx) to Nitrogen (N 2 ) and water (H 2 O). [0003] SCR catalysts that are generally distributed are premised on continuous use and use at an activation temperature (for example, 300° C. or higher). However, due to the low temperature of the engine exhaust gas discharged from the above-mentioned two-stroke diesel engine ...

AI Technical Summary

Problems solved by technology

[0009] However, the exhaust gas denitrification device for ships in Patent Document 1 uses a dedicated combustion-supporting burner to heat the engine exhaust gas, and there are problems such as the installation of the combustion-supporting burner and the high cost of fuel.

[0010] In addition, the low-temperature denitrification device of Patent Document 2 introduces the engine exhaust gas discharged from the diesel engine for power generation installed separately from the diesel engine into the exhaust flow path, but the flow rate of the engine exhaust gas discharged according to the load of the diesel engine for power generation and Since the temperature fluctuates, there is a problem that it is difficult to stably supply engine exhaust gas at the temperature required for regeneration of the denitration catalyst

And, as in Patent Document 2 figure 1 As shown, in the case where there are a plurality of diesel engines for power generation, a plurality of pipes for connecting these diesel engines for power generation and the denitration catalyst are required, and there is a problem that the device structure is complicated.

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