Atomizing jet-spray device for reducing agent for purifying exhaust nitric oxide of diesel engine

Abstract

The invention discloses a simply structured and efficient atomizing jet-spray device for a reducing agent for purifying exhaust nitric oxide of a diesel engine, which is implemented through the following technical scheme: a medium inlet pipe is communicated with a medium dispersion chamber, a medium strengthening preheating chamber is fixed under the medium dispersion chamber, the medium dispersion chamber is communicated with the medium strengthening preheating chamber through a tangential inlet, the bottom of the medium strengthening preheating chamber is communicated with a medium outlet pipe, four radial atomizing spraying holes are uniformly distributed on a peripheral surface at a tail end of the medium outlet pipe, a hemisphere having a flute is embedded in each spraying hole, and the spaying holes are communicated with the flute. The atomizing jet-spray device is simple in structure form, rational in design of the spaying holes and good in atomizing effect. The device has no influence on pressure drop of the whole exhaust line according to variation of work conditions of the engine, so that the device has no influence on power performance of the engine.

Description

technical field [0001] The invention belongs to the technical field of pollution control of nitrogen oxide emission from diesel engine tail gas, and further relates to an atomization injection device for a reducing agent for purifying nitrogen oxides in diesel engine tail gas. Background technique [0002] Diesel engines have been widely used in various industries due to their high thermal efficiency and low exhaust emissions, but their high nitrogen oxide emissions have long been a problem that plagues people. Selective catalytic reduction technology (Urea-SCR) is an effective method to control nitrogen oxides in diesel engines. This technology usually uses a certain concentration of urea solution (vehicle urea solution) to generate ammonia gas after evaporation, pyrolysis and hydrolysis for selective catalytic reduction. Nitrogen oxides from diesel engines. The quality of the atomization effect of the urea aqueous solution for vehicles directly affects the conversion effi...

AI Technical Summary

Problems solved by technology

Although the multi-hole atomizer is used to increase the cross-section of the effective atomization space, it still cannot cover most of the cross-section of the exhaust pipe

In addition, the aperture of the atomizing nozzle is usually 0.5-1 mm, and the diameter of the atomized droplet is generally above 50 μm, which seriously affects the urea solution supply accuracy of the Urea-SCR system and the efficiency of the SCR catalytic converter, and it is easy to form excessive spraying. However, if the atomized reducing agent fails to generate ammonia in time to participate in the catalytic reduction reaction, it will enter the ambient atmosphere along with the engine exhaust gas, eventually causing ammonia leakage and producing new pollutants to the environment.

[0004] In addition, when the engine exhaust gas flow passes through the atomized urea aqueous solution area, due to the penetration distance of the atomizing nozzle, the droplets with larger diameters are usually easily attached to the inner wall of the exhaust pipe to form urea crystals, which will corrode the exhaust pipe for a long time. Fittings for gas lines and atomizing nozzles

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