Tail gas denitration SCR (semiconductor control rectifier) system pipeline assembly of marine high-power diesel engine

Abstract

The invention discloses a tail gas denitration SCR (semiconductor control rectifier) system pipeline assembly of a marine high-power diesel engine. The tail gas denitration SCR system pipeline assembly comprises an air inlet pipeline, an air inlet awl, a purifier device, an air outlet awl, and an outlet pipeline, wherein one end of the air inlet pipeline is connected with a diesel engine exhaust gas pipeline, and the other end of the air inlet pipeline is connected with a circle flange of the air inlet awl; the purifier device is positioned between the air inlet awl and the air outlet awl, and is connected with the air inlet awl and the air outlet awl through the square; the exhaust gas pipeline is connected with the air outlet awl and a main discharge pipeline; and a mixer device and an ejector device are arranged in a pipe body, the two ends of the pipe body are provided with flanges, the pipe body is connected with the diesel engine exhaust gas pipeline through the upstream ends of the flanges, and the downstream ends of the flanges are connected with an air inlet awl circle flange of the air inlet awl. The tail gas denitration SCR system pipeline assembly provided by the invention has the advantages that the structure is reasonable, urea and tail gas are uniformly mixed, a vortex phenomenon in a pipeline is not generated, the utilization ratiou of urea is improved and the service life of equipment is prolonged, the velocity distribution of gas flow is uniform, and the conversion efficiency of NOx and utilization ratio of a catalyst are effectively improved.

Description

technical field [0001] The invention relates to an intake pipeline, in particular to a mixed intake pipeline, a catalyst installation pipeline and a flow channel of an exhaust pipeline of a marine high-power diesel engine tail gas denitrification SCR system. Background technique [0002] At present, due to the limited installation space, the pipelines of conventional small diesel engine exhaust denitrification SCR systems are generally designed with multiple bends and abrupt cross-sections. Because it uses a single catalyst, the gas flow is small and the flow velocity is fast, so it is less affected by the pipeline. Excessive curves and abrupt cross-section designs are not suitable for marine high-power diesel engine exhaust denitrification SCR systems. High-power diesel engines have large exhaust emissions and require large diameter exhaust pipes, making the velocity distribution of the same section uneven. Excessive bend design makes it easy for exhaust gas to appear vort...

AI Technical Summary

Problems solved by technology

Excessive bends and abrupt cross-section designs are not suitable for marine high-power diesel engine tail gas denitrification SCR systems. High-power diesel engine exhaust emissions are large, and the required exhaust pipe diameter is large, making the speed distribution of the same cross-section uneven.

Excessive bend design makes it easy for exhaust gas to appear vortex phenomenon on the downstream side of the bend when passing through the bend, resulting in the crystallization of urea on the pipe wall, which not only causes waste of urea, but also easily leads to the accumulation of high-concentration urea here for a long time. Corrosion of the road; the sudden cross-section design at the catalyst inlet will make the flow velocity distribution of the same cross-section uneven when the exhaust gas contacts the catalyst (the catalyst near the central axis of the intake pipe is directly impacted by the exhaust gas flow, while the exhaust gas passing through the edge zone catalyst is less), long-term operation It will lead to premature failure of the catalyst at the central axis of the high flow rate and incomplete utilization of the rest of the catalyst, which is not conducive to the long-term operation of the equipment

Therefore, the conventional SCR system pipeline cannot be applied to the exhaust gas denitrification of high-power diesel engines

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