A urea injection device for diesel engine exhaust aftertreatment

Abstract

The invention discloses a urea injection device for post-treatment of exhaust gas of a diesel engine, which comprises a spray device body, a stabilized air source, a water tank, a urea tank, and a signal detection control unit; the injection device body includes a shell, a powder cavity, and a powder cavity There is a powder inlet and a powder injection port on the body, and a needle valve is provided on the powder injection port; there is a conical water spray channel between the shell and the powder cavity, and a water inlet is set on the shell; the stabilized air source is connected to the water tank respectively. and a urea tank, as well as a water inlet and a powder inlet; the water tank is connected to the water inlet, and a water valve is provided on the water inlet pipe; the urea tank is connected to the powder inlet, and a urea powder valve is provided on the urea powder pipe. The urea powder of the present invention is stored separately from water, which avoids the problems of deterioration and uneven concentration distribution of the urea solution caused by long-term placement, and also avoids the problem that the urea solution may deteriorate during heating and melting treatment; Cracking reaction, improving conversion efficiency and expanding the working range.

Description

technical field [0001] The invention relates to the technical field of post-treatment of nitrogen and oxygen emissions from internal combustion engines, in particular to a urea injection device for after-treatment of diesel engine exhaust. Background technique [0002] Based on factors such as selective catalytic reduction technology having better fuel economy in post-treatment of diesel engine emissions, meeting Euro IV and Euro V emission regulations, a set of after-treatment devices can be shared, and it is not sensitive to the sulfur content of fuel. The selective catalytic reduction system has become the main technical means for diesel engines to meet Euro IV and Euro V emission standards. However, the current SCR (selective catalyst reaction) system sprays a urea solution containing 32.5% urea. The urea solution is stored as a mixture, and there are problems such as deterioration and uneven concentration of the solution after long-term storage; When the urea solution ...

AI Technical Summary

Problems solved by technology

However, the current SCR (selective catalyst reaction) system sprays a urea solution containing 32.5% urea. The urea solution is stored as a mixture, and there are problems such as deterioration and uneven concentration of the solution after long-term storage; When the urea solution is melted into ice, the solution causes urea to decompose and deteriorate.

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