CN219242023U - Urea nozzle and SCR urea injection system - Google Patents

Abstract

The utility model discloses a urea nozzle and an SCR urea injection system, which relate to the technical field of SCR urea injection systems, wherein a plurality of spray holes are annularly arranged along the side wall of a spray hole plate, a plurality of spray hole outlets are positioned on the outer side surface of the spray hole plate, and the spray hole outlets are divergently distributed along the side surface of the spray hole plate, so that the spray cone angle of urea injection is large, urea solution is effectively and rapidly dispersed, and the crystallization risk is reduced, and the specific scheme is as follows: the urea nozzle comprises a nozzle body, wherein an injection end of the nozzle body is connected with a jet orifice plate, the jet orifice plate is hollow to form a flow passage, the bottom of the jet orifice plate is closed, a plurality of jet orifices are arranged on the side wall of the jet orifice plate, the plurality of jet orifices are annularly arranged along the side wall of the jet orifice plate, and a plurality of jet orifice outlets are positioned on the outer side face of the jet orifice plate and are divergently distributed along the side face of the jet orifice plate in the jet orifice outlet direction.

Description

Urea nozzle and SCR urea injection system

Technical Field

The utility model relates to the technical field of SCR urea injection systems, in particular to a urea nozzle and an SCR urea injection system.

Background

The existing urea nozzle mainly comprises 3 holes and 6 holes, the urea nozzle is a core component of an SCR urea injection system, the urea injection plate is a core component of the urea nozzle, whether the design of the injection hole plate is reasonable or not directly determines the atomization effect of the nozzle, and the crystallization performance is influenced. Application number CN213235181U discloses a urea nozzle and SCR system, has seted up air jet hole and urea orifice respectively on the injection terminal surface of nozzle body, and the exit end of air jet hole and the exit end of urea orifice lie in the coplanar, and it improves urea crystallization risk in order to improve atomization effect, and this scheme has following problem:

1. the urea nozzles of the nozzles are designed on the same plane, urea is easy to gather during spraying, and cannot be rapidly dispersed, so that the spraying particle size is small, and meanwhile, the atomization cone angle of urea is small, so that the crystallization risk still exists;

2. the nozzle adopts an air-assisted injection system, the responsiveness is poor, and meanwhile, air spray holes are added, so that the design of an internal flow passage of the nozzle is complex, and the design cost of the nozzle is increased.

Disclosure of Invention

Aiming at the defects existing in the prior art, the utility model aims to provide a urea nozzle and an SCR urea injection system, so that the atomization cone angle of urea injection is large, the urea solution is effectively and rapidly dispersed, and the cost and crystallization risk are reduced; meanwhile, air holes are not required to be arranged, the complexity of the flow channel in the nozzle is reduced, and the overall design cost is reduced.

In order to achieve the above object, the present utility model is realized by the following technical scheme:

the urea nozzle comprises a nozzle body, wherein an injection end of the nozzle body is connected with a jet orifice plate, the jet orifice plate is hollow to form a flow passage, the bottom of the jet orifice plate is closed, a plurality of jet orifices are arranged on the side wall of the jet orifice plate, the plurality of jet orifices are annularly arranged along the side wall of the jet orifice plate, and a plurality of jet orifice outlets are positioned on the outer side face of the jet orifice plate and are divergently distributed along the side face of the jet orifice plate in the jet orifice outlet direction.

As a further implementation manner, the spray hole plate is in a frustum shape.

As a further implementation, the diameter of the bottom of the orifice plate is smaller than the diameter of the injection end of the nozzle body.

As a further implementation, the nozzle holes are arranged obliquely with respect to the nozzle plate axis.

As a further implementation manner, the spray holes are spirally distributed on the side wall of the spray hole plate.

As a further implementation, the spray hole is a circular hole.

As a further implementation mode, the spray holes penetrate through the side wall of the spray hole plate, a plurality of spray hole inlets are positioned on the inner wall surface of the spray hole plate, and a plurality of spray hole outlets are positioned on the outer wall surface of the spray hole plate and positioned on the same horizontal line.

As a further implementation, the tip shape of the orifice plate is adapted to the injection end shape of the nozzle body.

As a further implementation manner, the urea injection device further comprises an electromagnetic valve, wherein the electromagnetic valve is arranged on the nozzle body and is used for controlling urea injection.

An SCR urea injection system comprises a urea nozzle, wherein a nozzle body is connected with a urea pump.

The beneficial effects of the utility model are as follows:

according to the utility model, the spray holes are circumferentially arranged along the side wall of the spray hole plate, the spray hole outlets are positioned on the outer side surface of the spray hole plate, and the spray hole outlets are divergently distributed along the side surface of the spray hole plate, so that the spray cone angle of urea injection is large, urea solution is effectively and rapidly dispersed, and the crystallization risk is reduced; meanwhile, no air hole is needed, a non-air-assisted injection system is adopted, the process is easier to realize, the design of the flow passage in the nozzle is simple, and the cost is more advantageous.

Drawings

The accompanying drawings, which are included to provide a further understanding of the utility model and are incorporated in and constitute a part of this specification, illustrate embodiments of the utility model and together with the description serve to explain the utility model.

FIG. 1 is a schematic view of the overall structure of a urea nozzle according to an embodiment of the present utility model;

FIG. 2 is a schematic diagram of the structure of an orifice plate in an embodiment of the utility model;

fig. 3 is a schematic diagram of an orifice arrangement structure of an orifice plate according to an embodiment of the present utility model.

In the figure: the mutual spacing or dimensions are exaggerated for the purpose of showing the positions of the various parts, and the schematic illustration is only schematic.

Wherein: 1. the spray nozzle comprises a spray nozzle body, a spray hole plate and spray holes.

Detailed Description

It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the utility model. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this utility model belongs.

Jet plate: the jet hole structure of the direct jet nozzle head is to make several tiny holes on the thin plate, and the liquid is jetted out through the tiny holes.

It should be noted that there are two main reasons why the liquid can be atomized into droplets: firstly, the relative motion between the liquid and the medium outside the nozzle can be generated; secondly, the liquid is stretched into a liquid film or forms a thinner jet by utilizing a special structure. The nozzle mainly disperses continuous liquid into a large number of liquid drops in the two modes, so that the nozzle mainly realizes atomization in two modes: jet break-up and liquid film break-up. The mode of realizing atomization by the direct-injection nozzle is based on a jet flow crushing model, and the mode of realizing atomization by the rotational flow nozzle is based on a liquid film crushing model. Under the action of centrifugal force, the liquid forms a conical liquid film at the outlet of the nozzle, and under the mutual disturbance action with ambient air, the liquid film breaks to form tiny mist liquid drops.

Example 1

In a typical embodiment of the present utility model, referring to fig. 1-3, a urea nozzle includes a nozzle body 1, an injection end of the nozzle body 1 is fixedly connected with an injection hole plate 2, an interior of the injection hole plate 2 is hollow to connect the injection end of the nozzle body 1 and form a flow channel, a bottom of the injection hole plate 2 is closed, and a side wall of the injection hole plate 2 is provided with a plurality of injection holes 3.

As shown in fig. 2 and 3, the orifice plate 2 is in a frustum shape, the top end shape of the orifice plate 2 is matched with the shape of the injection end of the nozzle body 1, so that the orifice plate can be conveniently and effectively connected with the injection end of the nozzle body, and the orifice plate can be quickly replaced; the diameter of the bottom of the jet orifice plate 2 is smaller than the diameter of the jet end of the jet nozzle body 1, so that the side surface of the jet orifice plate is obliquely arranged relative to the axis of the jet orifice plate.

The spray holes 3 are annularly arranged along the side wall of the spray hole plate 2, the spray hole plate 2 on the spray nozzle body 1 of the embodiment is provided with eight spray holes 3, the outlets of the eight spray holes 3 are positioned on the outer wall surface of the spray hole plate 2, the directions of the outlets of the spray holes are annularly distributed along the side wall (side surface) of the spray hole plate 2, the directions of the outlets of each spray hole are different, the spray holes are outwardly dispersed, the atomization cone angle is increased, urea can be rapidly diffused, and the crystallization risk is reduced.

Further, eight orifices 3 are arranged obliquely relative to the axis of the orifice plate 2, and the orifices 3 are spirally distributed on the side wall of the orifice plate 2, the axis direction of each orifice 3 is different from the axis direction of other orifices 3, the orifices 3 penetrate through the side wall of the orifice plate 2, eight orifice inlets are positioned on the inner wall surface of the orifice plate 2, orifice outlets are positioned on the outer wall surface of the orifice plate 2 and on the same horizontal line, namely, the outlet heights of the orifices 3 are the same, and the inlet heights of the orifices are the same.

The nozzle body 1 is further provided with a switch valve, the switch valve adopts an electromagnetic valve, the electromagnetic valve is used for controlling whether European urea is injected and controlling urea injection quantity, and other structures of the nozzle body can be connected by adopting the prior art, and the spray hole plate structure of the nozzle is optimized in the embodiment.

In some examples, the nozzle hole may be a hole of another shape, and in order to achieve uniformity of urea spraying, the nozzle hole is preferably a circular hole, so as to achieve a better atomization effect.

The embodiment can achieve the aim without changing the overall design structure of the urea nozzle, the spray hole plate can be completely interchanged with the existing urea nozzle in installation, the spray hole is arranged through the structure of the spray hole, the spray cone angle of urea injection is large, the urea solution is effectively and rapidly dispersed, the crystallization risk is reduced, a non-air assisted injection system is adopted, the process is easier to realize, and the cost is more advantageous.

Example two

The embodiment provides an SCR urea injection system, which comprises a urea nozzle in the first embodiment, wherein the nozzle body is connected with a urea pump, and the SCR urea injection system is used for metering and injecting urea (reducing agent) into a reactor according to a specified quantity. The most mainstream of the diesel exhaust aftertreatment technology is a Selective Catalytic Reduction (SCR) technology, and the main principle of the SCR technology is to spray urea into the exhaust, hydrolyze the urea into ammonia, react with nitrogen oxides in the exhaust under the action of a catalyst, and reduce the nitrogen with the reducibility harmless to the environment.

It will be appreciated that the injection system is a core component in the SCR system, and that the crystallization problem of the nozzle directly affects the conversion efficiency of the SCR system.

The current main stream injection system has a non-air-assisted injection system and an air-assisted injection system, the air-assisted injection system needs an auxiliary air source to improve nozzle atomization, but an air hole is needed to be designed, an inner flow channel of the nozzle is complex, so that the cost is high, the non-air-assisted injection system is provided, the layout of spray holes on a spray hole plate is optimized, the atomization cone angle and the spray particle size are increased, urea is effectively and rapidly diffused, and the crystallization risk is reduced.

The above description is only of the preferred embodiments of the present utility model and is not intended to limit the present utility model, but various modifications and variations can be made to the present utility model by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model should be included in the protection scope of the present utility model.

Claims (10)

1. The urea nozzle is characterized by comprising a nozzle body, wherein the injection end of the nozzle body is connected with a nozzle plate, the inside of the nozzle plate is hollow to form a flow channel, the bottom of the nozzle plate is closed, the side wall of the nozzle plate is provided with a plurality of nozzle holes, the plurality of nozzle holes are annularly arranged along the side wall of the nozzle plate, and a plurality of nozzle hole outlets are positioned on the outer side surface of the nozzle plate and the nozzle hole outlet directions are divergently distributed along the side surface of the nozzle plate.

2. A urea nozzle according to claim 1, wherein the orifice plate is frusto-conical.

3. A urea nozzle according to claim 2, wherein the diameter of the bottom of the orifice plate is smaller than the diameter of the spray end of the nozzle body.

4. A urea nozzle according to claim 1, wherein the orifice is arranged obliquely with respect to the orifice plate axis.

5. A urea nozzle according to claim 4, wherein the orifices are helically arranged in the side wall of the orifice plate.

6. A urea nozzle according to claim 5, wherein the orifice is a circular orifice.

7. The urea nozzle according to claim 4, wherein the nozzle penetrates through the side wall of the nozzle plate, the nozzle inlets are positioned on the inner wall surface of the nozzle plate, and the nozzle outlets are positioned on the outer wall surface of the nozzle plate and on the same horizontal line.

8. A urea nozzle according to claim 1, wherein the tip end shape of the orifice plate is adapted to the shape of the spray end of the nozzle body.

9. The urea nozzle of claim 1, further comprising a solenoid valve disposed on the nozzle body for controlling urea injection.

10. An SCR urea injection system comprising a urea nozzle according to any one of claims 1-9, the nozzle body being connected to a urea pump.

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