Compact large diesel engine tail gas treatment device and method

Abstract

The invention discloses a compact large diesel engine tail gas treatment device and method. The device comprises an air inlet assembly, a DOC assembly, a DPF assembly, a mixing assembly, a SCR assembly and an exhausting and silencing assembly which are connected in series successively. The mixing assembly comprises a hollow mixing pipe, the mixing pipe penetrates a collector plate, and one part ofthe mixing pipe is located on one side of the collector plate while the other part of the mixing pipe is located on the other side of the collector plate; swirl vanes are arranged on the upper part of the mixing pipe, at least one flow dividing window is arranged at the bottom, and the swirl vanes and the dividing windows are separately located on two sides of the collector plate; the space on one side of the collector plate communicates to the DPF assembly while the space on the other side of the collector plate communicates to the SCR assembly. A urea mixer and the mixing pipe are arrangedin a reactor, so that the compact large diesel engine tail gas treatment device is compact in structure and can meet the demand of a large diesel engine on tail gas treatment.

Description

technical field [0001] The invention relates to the technical field of engine exhaust purification treatment, in particular to a compact and large diesel engine tail gas treatment device and method. Background technique [0002] Due to the incomparable advantages of gasoline engines in terms of power, economy and reliability, diesel engines have been widely used, especially low carbon dioxide emissions. However, the harm caused by diesel exhaust pollution has attracted increasing attention. The increasingly stringent national emission regulations have prompted domestic diesel engine manufacturers to find effective ways to control and reduce emissions of pollutants. The current national regulations clearly specify PM (Particulate Matter), PN (Particulate Number) and NOx requirements for 130-560kW non-road diesel engines Therefore, DPF (Diesel Particulate Filter) and SCR (selective catalytic reduction) technologies are currently the best choice for my country's off-road heavy-d...

AI Technical Summary

Problems solved by technology

A series of complex chemical reactions will occur in the process of hydrolysis to generate ammonia, and with the chemical reactions, a variety of intermediate products will be produced, such as cyanuric acid, which will adhere to the wall of the SCR mixer and mixing tube to form stones, commonly known as Crystallization, for large-displacement engines, the NOx emission is large, and the reaction requires a large amount of urea aqueous solution. The cooling effect on the wall surface is obvious, and a long pipeline is required for urea decomposition. If the design is not proper, it is easy to form stones, or the NOx emission is not good. up to standard

[0006] At present, DPF and SCR systems have been applied to vehicle and engine applications, but for 400kW-560k heavy-duty diesel engines, currently limited by the manufacturing technology of the core component carrier of DPF and SCR systems, the maximum size cannot meet the current 400kW-560kW heavy-duty diesel engines application, if simply considering the arrangement in series (such as figure 1 As shown), the back pressure will be extremely high, which will seriously affect the fuel economy of the diesel engine. At the same time, it will cause a long series length. On the horizontal plane, the layout of the reactor system is severely restricted

If the parallel connection method is simply considered, and the length required for urea decomposition is considered at the same time, the overall volume will increase, and the layout space will be limited on the horizontal or vertical plane.

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