The urea nozzle of SCR system and mounting structure thereof
Technical field
The present invention relates to diesel car vent gas treatment technical field, particularly relate to the urea nozzle of a kind of SCR system, the invention still further relates to the mounting structure of urea nozzle.
Background technique
Selective Catalytic Reduction SCR is called for short SCR; SCR is meant and is installed in the diesel car vent systems; NOx in the diesel emission is catalysed and reduced into the catalytic reduction device of N2 and H2O, selects aqueous solution of urea as reducing agent.Aqueous solution of urea is ejected in the outlet pipe at the catalyzer upper reaches, is decomposed into CO2 and ammonia in the effect gasified of EGT and air-flow, and ammonia is reduced into free of contamination nitrogen G&W as reducing agent with NOx.Urea liquid must be according to engine operating condition situation quantitative injection, so the logic control circuit of quantitative injection unit is connected with control unit of engine.The working efficiency of SCR depends on gas temperature, if 200 ℃ to 500 ℃ temperature work, it is most effective to reach 95%, and the operational condition of actual vehicle can reach this requirement.So the SCR technology can satisfy state's IV, state's V emission regulation demands fully.
The SCR system mainly is made up of urea box, urea pump (urea supply unit), urea nozzle, catalytic muffler, urea pipe and control unit etc., and is as shown in Figure 1.
The working principle of SCR is that reducing agent (ammoniacal liquor, urea etc.) is sprayed in the outlet pipe, under the effect of catalyzer, is reduced into nitrogen to nitrogen oxide, to reach the purpose that reduces discharged nitrous oxides.The reducing agent fogging degree that sprays in the outlet pipe is high more, and its response area is big, reacts more abundant, and reduction effect is better.The atomizing effect of reducing agent is the core of SCR, and the quality of the performance of atomizer nozzle decision atomizing effect.
Summary of the invention
Technical problem to be solved by this invention is technological to above-mentioned SCR and a kind of air atomizer spray nozzle design, and this nozzle interior is porose, and the outlet in hole is the micropore of opening on the least significant end circumferential surface.Feed aqueous solution of urea in the nozzle and feed high-pressure air simultaneously, utilize the effect of sending forth of high-pressure air, carrying aqueous solution of urea secretly with higher speed and spraying from micropore, making the atomization of liquid is thinner drop.Air atomizer spray nozzle has advantages such as atomization quality height, the gas consumption rate is low, radiations heat energy is few, supply system is simple and reliable.Nozzle mounting points of the present invention is no less than in the 200mm scope apart from the catalytic muffler entry end.
The technical problem that the present invention requires to solve can realize through following technological scheme:
The urea nozzle of a kind of SCR system comprises nozzle connection, nozzle straight tube, nozzle shower nozzle, and said nozzle connection is a column, and the bottom is thicker than top, and the position, intermediate portion has a circle protruding, and there is through hole said nozzle connection inside, and the aperture, bottom is greater than the aperture of epimere part; Said nozzle straight tube is a column, and there is through hole inside, and said nozzle straight tube one end is inserted in that bigger sector hole of aperture, nozzle connection bottom; Said nozzle shower nozzle is a funnel-like; By the bigger cylinder of upper diameter, the less cylinder of diameter and one section round platform connecting two cylinders are formed bottom; There is a circle boss the top of the cylinder that diameter is bigger; Said nozzle shower nozzle inside is shoulder hole, and the outlet of said shoulder hole is at least one micropore that open the less cylinder bottom of diameter, and said nozzle shower nozzle is through the other end of inner step borehole jack at the nozzle straight tube.
Said micro-pore diameter is 0.3mm-1.0mm.
Said nozzle connection, three parts of nozzle straight tube and nozzle shower nozzle adopt soldering or laser beam welding to be connected.
Said urea nozzle is installed on the inclined-plane of vehicle exhaust pipeline, in the scope of catalyst converter inlet more than or equal to 200mm of said urea nozzle apart from the SCR system.
Owing to adopted as above technological scheme, the present invention has following characteristics: have advantages such as atomization quality height, the gas consumption rate is low, radiations heat energy is few, supply system is simple and reliable.
Description of drawings
Fig. 1 is the SCR system block diagram.
Fig. 2 is a structural drawing of the present invention.
Fig. 3 is a nozzle connection sectional view of the present invention.
Fig. 4 is a nozzle straight tube sectional view of the present invention.
Fig. 5 is a nozzle shower nozzle sectional view of the present invention.
Fig. 6 is a nozzle shower nozzle tightening nut sectional view of the present invention.
Fig. 7 partly cuts open figure for nozzle shower nozzle mounting base of the present invention.
Fig. 8 is a mounting structure schematic representation of the present invention.
Embodiment
For technological means, creation characteristic that the present invention is realized, reach purpose and effect and be easy to understand and understand, below in conjunction with concrete diagram, further set forth the present invention.
As shown in Figure 2, the present invention includes nozzle connection 100, nozzle straight tube 200, nozzle shower nozzle 500, the structure of nozzle connection of the present invention 100, nozzle straight tube 200, nozzle shower nozzle 500 such as Fig. 3, Fig. 4, Fig. 5, shown in Figure 6.Nozzle connection 100 is up-thin-low-thick column structure, and there is through hole inside, and the structure in hole also is up-thin-low-thick.Nozzle straight tube 200 is straight column structure, and also there is through hole inside.Nozzle shower nozzle 500 is a funnel-shaped structure, and there is shoulder hole inside, and the outlet of shoulder hole is nozzle shower nozzle 500 micropore of bottom bottom, and the micropore of present embodiment has three, and the diameter of micropore is in the scope of 0.3mm-1.0mm.Nozzle straight tube 200 1 ends are inserted in the nozzle connection 100, and the other end is inserted in the nozzle shower nozzle 500.Above-mentioned each assembly connects through the mode of soldering or laser beam welding.
Mounting structure of the present invention is as shown in Figure 9, and nozzle shower nozzle 500 is fixed on tightening nut 300 bottoms, and tightening nut 300 is spun on the mounting base 400 through screw thread.The structure of tightening nut 300 and mounting base 400 is respectively like Fig. 7, shown in Figure 8.
Aqueous solution of urea and high-pressure air are passed into nozzle interior, utilize the effect of sending forth of high-pressure air, are carrying aqueous solution of urea secretly with higher speed and are spraying from micropore, get into catalyst converter, and the tail gas that diesel car is discharged reduces.
More than show and described basic principle of the present invention, major character and advantage of the present invention.The technician of the industry should understand; The present invention is not restricted to the described embodiments; That describes in the foregoing description and the specification just explains principle of the present invention; The present invention also has various changes and modifications under the prerequisite that does not break away from spirit and scope of the invention, and these variations and improvement all fall in the scope of the invention that requires protection.The present invention requires protection domain to be defined by appending claims and equivalent thereof.