CN116291813A

CN116291813A - Urea injection device, automobile exhaust treatment system and urea solution atomization method

Info

Publication number: CN116291813A
Application number: CN202310282877.3A
Authority: CN
Inventors: 李天维; 王天斌; 向福冲
Original assignee: Shenzhen Blue Valley Intelligent Equipment R&d Co ltd
Current assignee: Shenzhen Blue Valley Intelligent Equipment R&d Co ltd
Priority date: 2023-03-14
Filing date: 2023-03-14
Publication date: 2023-06-23
Also published as: WO2024187625A1

Abstract

The invention provides a urea injection device, an automobile tail gas treatment system and a urea solution atomization method; the urea injection device comprises an injection device and a bracket, wherein one end of the injection device is provided with a nozzle, and an air source channel communicated with the nozzle and a liquid source channel communicated with the air source channel are arranged in the injection device; the bracket is arranged at one side of the injection device far away from the nozzle, and an air inlet valve and a liquid inlet valve with internal channels are arranged in the bracket; one end of the air inlet valve is communicated with the air source channel, the other end of the air inlet valve is used for being connected with the first air source, and the air inlet valve can control the on-off of the air source channel and the first air source; one end of the liquid inlet valve is communicated with the liquid source channel, the other end of the liquid inlet valve is used for being connected with a liquid source, and the liquid inlet valve can control the on-off of the liquid source channel and the liquid source. The urea solution can be scattered into tiny liquid particles by means of high-speed air flow, so that the urea solution is atomized, and the atomized liquid particles can be fully contacted with automobile exhaust, so that the automobile exhaust treatment effect is improved.

Description

Urea injection device, automobile exhaust treatment system and urea solution atomization method

Technical Field

The invention relates to the field of automobile exhaust treatment, in particular to a urea injection device, an automobile exhaust treatment system and a urea solution atomization method.

Background

Nowadays, the automobile industry rapidly develops, and the development of the automobile drives economic growth, and meanwhile, some hazards are brought to us, such as exhaust emission of the automobile is one of the hazards. Among them, it is common to treat automobile exhaust by SCR (selective catalytic reduction).

In this treatment, a urea injection device is used, and the urea injection device is used to inject the urea aqueous solution into the exhaust system, decompose the urea aqueous solution into ammonia in the exhaust gas stream, and react with nitrogen oxides under the action of a catalyst to convert the ammonia into harmless nitrogen and water.

The conventional automobile urea injection device generally uses a urea pump to pump urea, and the injection mode leads to larger injected urea particles and insufficient reaction with tail gas. The above problems are technical problems to be solved in the art.

Disclosure of Invention

The invention mainly solves the technical problem of how to enable urea to be in full contact with automobile exhaust.

According to a first aspect, there is provided a urea injection device comprising:

the device comprises an injection device, wherein one end of the injection device is provided with a nozzle, and an air source channel communicated with the nozzle and a liquid source channel communicated with the air source channel are arranged in the injection device;

the bracket is arranged on one side of the injection device, which is far away from the nozzle, and an air inlet valve and a liquid inlet valve with internal channels are arranged in the bracket;

one end of the air inlet valve is communicated with the air source channel, the other end of the air inlet valve is used for connecting a first air source, and the air inlet valve can control the on-off of the air source channel and the first air source; one end of the liquid inlet valve is communicated with the liquid source channel, the other end of the liquid inlet valve is used for being connected with a liquid source, and the liquid inlet valve can control the on-off of the liquid source channel and the liquid source.

In an optional embodiment, a blowback valve with an internal channel is further arranged in the bracket, one end of the blowback valve is communicated with one end of the liquid inlet valve, which is used for being connected with a liquid source, the other end of the blowback valve is used for being connected with a second gas source, and the blowback valve can control the on-off of the liquid inlet valve and the second gas source.

In an alternative embodiment, the device further comprises a heat-insulating shell, the support is arranged in the heat-insulating shell, and one end of the air inlet valve for receiving gas, one end of the liquid inlet valve for receiving liquid and one end of the blowback valve for receiving gas are all positioned outside the heat-insulating shell; the heat preservation shell with annotate the liquid chamber has between the lateral surface of support, set up on the heat preservation shell with annotate liquid hole and the flowing back hole of liquid chamber intercommunication.

In an alternative embodiment, the heat-insulating shell is provided with a heat-insulating jacket and a cover body, the cover body is covered on one end of the heat-insulating jacket, and the injection device is covered on the other end of the heat-insulating jacket; the liquid injection cavity is defined by the inner side wall of the heat preservation jacket and the outer side wall of the support, and two ends of the liquid injection cavity are respectively sealed through the cover body and the injection device.

In an alternative embodiment, the air inlet valve, the liquid inlet valve and the blowback valve are fixed in the bracket by the cover body in a pressing way; the inlet valve is used for receiving one end of gas, the liquid inlet valve is used for receiving one end of liquid and the blowback valve is used for receiving one end of gas all pass the lid, and extend to the lid is kept away from the one side of support.

In an alternative embodiment, the bracket is provided with a first gas channel, a liquid channel and a second gas channel; the air inlet valve is communicated with the air source channel through the first air channel; the liquid inlet valve is communicated with the liquid source channel through the liquid channel; the blowback valve is communicated with the liquid inlet valve through the second gas channel.

In an alternative embodiment, one or more of the intake valve, the blowback valve, and the intake valve are solenoid valves.

According to a second aspect, an automobile exhaust treatment system is provided, comprising the urea injection device described above.

According to a third aspect, there is provided a urea solution atomization method based on the urea injection device described above, comprising the steps of:

opening the air inlet valve, introducing compressed gas into the air inlet valve, enabling the compressed gas to sequentially pass through the air inlet valve and the air source channel, and then discharging the compressed gas through a nozzle;

opening a liquid inlet valve, connecting the liquid inlet valve with urea solution, enabling the urea solution to sequentially pass through the liquid inlet valve and the liquid source channel, then entering the gas source channel, scattering and atomizing by compressed gas, and spraying by a nozzle, so as to finish atomization.

According to a fourth aspect, there is provided a urea solution atomization method based on the urea injection device described above, comprising the steps of:

opening the liquid inlet valve, connecting the liquid inlet valve with urea solution, keeping the back blowing valve closed, enabling the urea solution to sequentially pass through the liquid inlet valve and the liquid source channel, then entering the air source channel, scattering and atomizing by compressed gas, and spraying by a nozzle to finish atomization;

after atomization is completed, the liquid inlet valve is closed, the back blowing valve is opened, back blowing gas is introduced into the back blowing valve, so that the back blowing gas sequentially passes through the back blowing valve and the liquid inlet valve, and one end of the liquid inlet valve for receiving liquid is discharged.

The beneficial effects of this application lie in: the urea solution can be scattered into tiny liquid particles by means of high-speed air flow, so that the urea solution is atomized, and the atomized liquid particles can be fully contacted with automobile exhaust, so that the automobile exhaust treatment effect is improved.

Drawings

FIG. 1 is a schematic perspective view of an embodiment of the present application;

FIG. 2 is a top view of one embodiment of the present application;

FIG. 3 is a cross-sectional view at A-A in FIG. 2;

FIG. 4 is a schematic illustration of fluid flow during atomization in one embodiment of the present application;

FIG. 5 is a schematic diagram of the flow direction of the fluid during blowback in one embodiment of the present application;

FIG. 6 is a flow chart of fluid during atomization of an ejector in one embodiment of the present application;

fig. 7 is a schematic diagram of a urea solution atomization process in an embodiment of the present application.

Reference numerals: the injection device 1, the nozzle 11, the air source channel 12, the receiving part 121, the mixing part 122, the liquid source channel 13, the negative pressure chamber 14, the vortex groove 15, the bracket 2, the air inlet valve 21, the liquid inlet valve 22, the blowback valve 23, the first mounting hole 24, the second mounting hole 25, the third mounting hole 26, the first air channel 27, the liquid channel 28, the second air channel 29, the heat-insulating shell 3, the temperature jacket 31, the cover body 32, the liquid injection cavity 4, the liquid injection hole 41 and the liquid discharge hole 42.

Detailed Description

The invention will be described in further detail below with reference to the drawings by means of specific embodiments. Wherein like elements in different embodiments are numbered alike in association. In the following embodiments, numerous specific details are set forth in order to provide a better understanding of the present application. However, one skilled in the art will readily recognize that some of the features may be omitted, or replaced by other elements, materials, or methods in different situations. In some instances, some operations associated with the present application have not been shown or described in the specification to avoid obscuring the core portions of the present application, and may not be necessary for a person skilled in the art to describe in detail the relevant operations based on the description herein and the general knowledge of one skilled in the art.

Furthermore, the described features, operations, or characteristics of the description may be combined in any suitable manner in various embodiments. Also, various steps or acts in the method descriptions may be interchanged or modified in a manner apparent to those of ordinary skill in the art. Thus, the various orders in the description and drawings are for clarity of description of only certain embodiments, and are not meant to be required orders unless otherwise indicated.

The numbering of the components itself, e.g. "first", "second", etc., is used herein merely to distinguish between the described objects and does not have any sequential or technical meaning. The terms "coupled" and "connected," as used herein, are intended to encompass both direct and indirect coupling (coupling), unless otherwise indicated.

As shown in fig. 1 to 3, the present application discloses a urea injection device, which comprises an injection device 1 and a bracket 2.

As shown in fig. 1, 3 to 5, the injection device 1 is arranged at one end of the bracket 2, one side of the injection device 1 is provided with a nozzle 11, and the nozzle 11 is used for atomizing injection; in the embodiment disclosed in the application, the support 2 is of a cylindrical structure, the shell of the injection device 1 is disc-shaped, the injection device 1 is connected with the support 2 and fixed at the bottom of the support 2, and the nozzle 11 is located at one side of the injection device 1 away from the support 2.

In the injection device 1, the internal structure of the injection device comprises an air source channel 12 and a liquid source channel 13, wherein the air source channel 12 is coaxially arranged and communicated with the nozzle 11; one end of the liquid source channel 13 is connected to a side wall of the air source channel 12, for example, as shown in fig. 6, a connecting hole is formed on a side wall of a connection portion between the air source channel 12 and the nozzle 11, and one end of the liquid source channel 13 is connected to the connecting hole and then is connected to the air source channel 12.

In a specific example, the air source channel 12 comprises a receiving part 121 and a mixing part 122 which are sequentially communicated from top to bottom, wherein the lower end of the mixing part 122 is connected with the nozzle 11, the upper end of the receiving part 121 extends to one side of the injection device 1 close to the bracket 2, and an air inlet is formed on the inlet surface for air to enter; the gas enters the gas source channel 12 from the receiving part 121, passes through the mixing part 122 and finally is atomized and sprayed out from the nozzle 11. The liquid source channel 13 is arranged on one radial side of the gas source channel 12; specifically, the liquid source channel 13 has a liquid inlet end and a liquid outlet end, wherein the liquid inlet end is an opening formed by the surface of the liquid source channel 13 extending to one side of the injection device 1 close to the bracket 2; through the liquid inlet end, the liquid source channel 13 can be abutted with a liquid source. In some alternative designs, as shown in FIG. 6, the air supply passage 12 is designed so that the air flow is maximized at the mixing section 122

For example, in one example, in order to increase the flow rate of the compressed gas passing through the mixing part 122, the inner diameter of the mixing part 122 is gradually reduced from the receiving part 121 toward the nozzle 11, and the gas flow rate is gradually increased as the sectional area is reduced, so that the gas flow rate reaches a maximum value when the gas reaches the junction of the mixing part 122 and the nozzle 11. In addition, in order to further increase the fluid velocity, as shown in fig. 6, the inner diameter of the nozzle 11 is gradually enlarged in a direction away from the mixing part 122, and at this time, the mixing part 122 and the nozzle 11 are combined to form a structure similar to a laval tube, and when the fluid is ejected through the mixing part 122, the inner side of the nozzle 11 is provided with a slope-out structure, so that the fluid is not easy to adhere when passing through, and residues of the fluid at the nozzle 11 are reduced. It should be understood that the air source channel 12 may also adopt other structures capable of forming high-speed air flow, and the present application is not limited thereto

The liquid outlet end is communicated with the mixing part 122, so that the liquid can flow into the mixing part 122 after entering from the liquid inlet end. It should be understood that the liquid outlet end may be in communication with the mixing portion 122 through one or more intervening spaces; for example, as shown in fig. 6, in the embodiment provided in the application, the ejector 1 is further provided with a negative pressure chamber 14, the negative pressure chamber 14 entirely surrounds the outer side of the mixing portion 122, and a plurality of through holes are formed in the side wall of the mixing portion 122, so that the negative pressure chamber 14 can be communicated with the mixing portion 122, and the liquid outlet end is communicated with the negative pressure chamber 14, so as to be indirectly communicated with the mixing portion 122. On the basis of the above, in order to enable the liquid to enter the negative pressure chamber 14 and the mixing part 122 more uniformly, a plurality of liquid outlet ends are provided, and a plurality of liquid outlet ends are arranged around the air source channel 12 and are communicated with the negative pressure chamber 14.

In the embodiment disclosed in the application, a first gas channel 27 and a liquid channel 28 are formed in the bracket 2; as shown in fig. 2 to 5 for example, the first gas channel 27 and the liquid channel 28 are both formed inside the bracket 2 along the axial direction of the bracket 2, the bottom end of the first gas channel 27 is in butt joint with the air inlet of the air source channel 12 in the injection device 1, and the bottom end of the liquid channel 28 is communicated with the liquid source channel 13 in the injection device 1.

On the basis, as shown in fig. 1 to 5, an air inlet valve 21 and a liquid inlet valve 22 are also installed in the bracket 2, internal channels are formed in the air inlet valve 21 and the liquid inlet valve 22, and the air inlet valve 21 and the liquid inlet valve 22 are respectively provided with a valve core, and the valve core moves in the internal channel of the air inlet valve 21 or the internal channel of the liquid inlet valve 22, so that the on-off of the internal channel of the air inlet valve 21 and the first gas channel 27 and the on-off of the internal channel of the liquid inlet valve 22 and the liquid channel 28 can be controlled; the air inlet valve 21 is communicated with the air source channel 12 through the first air channel 27, and one end of the air inlet valve 21, which is far away from the first air channel 27, is used for receiving air, and the end of the air inlet valve 21, which is used for receiving air, is defined as an inlet end of the air inlet valve 21 in the application; the liquid inlet valve 22 is in communication with the liquid source channel 13 through the liquid channel 28, and the end of the liquid inlet valve 22 away from the liquid channel 28 is used for receiving liquid, and the end of the liquid inlet valve 22 away from the liquid channel 28 is defined as the inlet end of the liquid inlet valve 28 in the present application. One end of the air inlet valve 21, which is far away from the first air channel 27, is used for being in butt joint with a first air source, and the on-off of the air source channel 12 and the first air source can be controlled through the air inlet valve 21; the end of the liquid inlet valve 22 far away from the liquid channel 28 is used for introducing liquid, and the on-off of the liquid source channel 28 and the liquid source can be controlled through the liquid inlet valve 22.

In addition, in some alternative designs, a second gas channel 29 is also formed in the bracket 2; one end of the second gas channel 29 is connected to the inlet end of the liquid inlet valve 22, and the gas can flow to the inlet end of the liquid inlet valve 22 through the second gas channel 29. The end of the second gas channel 29 far away from the liquid inlet valve 22 is used for being connected with a second gas source, and on the basis, the on-off of the second gas channel 29 and the second gas source is controlled; a blowback valve 23 is also installed in the bracket 2, the blowback valve 23 is similar to the air inlet valve 21 and the liquid inlet valve 22, a valve core and an internal channel are also arranged in the blowback valve 23, and the valve core of the blowback valve 23 can move to control the on-off of the internal channel; one end of the blowback valve 23 is in butt joint with the second gas channel 29, the second gas channel 29 is communicated with the internal channel of the blowback valve 23, and the other end of the blowback valve 23 is used for receiving gas, so that the end of the blowback valve 23 receiving gas is defined as an inlet end of the blowback valve. The gas can enter from the inlet end of the blowback valve 23 and is discharged through the inlet end of the liquid inlet valve 22, and the on-off of the internal channel and the second gas channel 2 can be controlled through the blowback valve 23, so that the on-off of the blowback valve 23 and the liquid inlet valve 22 is controlled.

As shown in fig. 2 to 5 in the specific example, three mounting holes are formed in the bracket 2 along the axial direction of the bracket 2, and are defined as a first mounting hole 24, a second mounting hole 25 and a third mounting hole 26 in the present application; wherein, the first gas channel 27 is formed at the bottom end of the first mounting hole 24, and the air inlet valve 21 is sleeved in the first mounting hole 24, so that the internal channel of the air inlet valve 21 can be communicated with the first gas channel 27; the liquid channel 28 is arranged at the bottom end of the second mounting hole 25, and the liquid inlet valve 22 is sleeved in the third mounting hole 26 so as to be communicated with the liquid channel 28; the second gas channel is formed at the bottom end of the third mounting hole 26, and the blowback valve 23 is sleeved in the second mounting hole 26, so that it is communicated with the second gas channel 29.

In using the present application for atomization, a specific workflow is shown in fig. 7, and specific steps are as follows:

before operation, the inlet valve 21 may be connected to a first source of compressed air; the inlet valve 22 is docked with a container containing urea solution, it being understood that the inlet valve 22 may be directly connected with the container containing urea solution in order to make it easier for urea solution to enter the inlet valve 22. The blowback valve 23 is connected to a second air source, which may be the same or different from the first air source, without being excessively limited in this application.

In operation, firstly, judging whether atomization injection of urea solution is required, and if so, opening the air inlet valve 21 and the liquid inlet valve 22; it is contemplated that in some embodiments, the blowback valve 23 is further provided, and in actual operation, the liquid inlet valve 22 and the blowback valve 23 are not simultaneously in a closed or open state, that is, when the liquid inlet valve 22 is opened, the blowback valve 23 needs to be kept in a closed state, so as to avoid liquid from being discharged through the blowback valve 23. Then, the first air source is opened, and the internal channels of the air inlet valve 21 are all in a communication state, so that the compressed air can flow along the path a in fig. 4 and 6, that is, the compressed air can sequentially pass through the air inlet valve 21, the first air channel 27 and the air source channel 12, and the high-speed air flow can form a high-speed air flow after passing through the injection device 1 and then is discharged through the nozzle 11. After or while introducing the compressed gas, the compressed gas will form a high-speed air flow in the injection device 1, and the high-speed air flow will take away the surrounding air, so that a negative pressure is formed around the high-speed air flow and near the connection between the liquid source channel 13 and the air source channel 12, and the internal channel of the liquid inlet valve 22 is in a communicating state, so that the liquid is pumped to the air source channel 12, and at this time, the urea solution will flow along the path b in fig. 4 and 6, i.e. the urea solution will sequentially pass through the liquid inlet valve 22, the liquid channel 28 and the liquid source channel 13. When the liquid enters the liquid source channel 13, the liquid is dispersed in the gas source channel 12 by high-speed air flow, small liquid particles are formed and then sprayed out of the nozzle 11 along with the air flow, so that atomization is completed.

The urea solution can be atomized to be applied to the SCR reaction process of automobile exhaust treatment; on the other hand, in order to avoid urea crystallization from the urea solution remaining in the liquid channel 28, in some alternative designs, the back-flushing valve 23 and the second gas channel 29 of the above embodiment are also installed in the above-mentioned holder 2.

After the urea solution is injected for a period of time, if the discharge amount of the urea solution has reached the set discharge amount, the liquid inlet valve 22 and the air inlet valve 21 are closed, and the blowback valve 23 is opened; at this time, the liquid inlet valve 22 is kept in a closed state, that is, the liquid source is not communicated with the liquid source channel 13 any more; when the second air source is opened, the blowback valve 23 is opened, the liquid inlet valve 22 is closed, and the air for blowback enters the liquid inlet valve 22 through the second air channel 29, and the urea solution is blowback discharged out of the liquid inlet valve 22 through the inlet end of the liquid inlet valve 22, so that the residual urea solution is returned to the urea container from new, and the urea solution is prevented from crystallizing in the liquid inlet valve 22.

It should be understood that the above-mentioned air intake valve 21, blowback valve 23 and intake valve 22 may be selected from existing valve structures, such as pneumatic valves, hydraulic valves, etc., and are not limited thereto. In the example of the present application, solenoid valves are used for the intake valve 21, the intake valve 22, and the blowback valve 23. Specifically, electromagnetic coils are sleeved outside the air inlet valve 21, the liquid inlet valve 22 and the blowback valve 23; correspondingly, the air inlet valve 21, the liquid inlet valve 22 and the blowback valve 23 are also internally provided with a first valve core, a second valve core and a third valve core, and the electromagnetic coil can control the movement of the magnetic valve core by electrifying or de-electrifying, so as to control the on-off of the air inlet valve 21, the liquid inlet valve 22 and the blowback valve 23.

Referring to fig. 6, in the embodiment disclosed in the present application, a vortex groove 15 recessed along the axial direction of the injection device 1 is formed in the bottom surface of the injection device 1, the vortex groove 15 is disposed around the nozzle 11, one end of the nozzle 11 away from the mixing portion 122 protrudes out of the inner end surface of the vortex groove 15, and the outer diameter of the nozzle 11 gradually decreases toward the direction away from the mixing portion 122; the area defined by the outer side wall of the nozzle 11 and the inner side wall of the swirl groove 15 is defined as a swirl zone. In the spraying process, after the atomized liquid is sprayed, the airflow speed sprayed at the moment still has higher speed, and as the nozzle 11 is arranged in the vortex groove 15, a vortex area surrounds the outer side of the nozzle 11 and is limited by the side wall of the vortex area, and a vortex is formed in the vortex area under the drive of high-speed airflow, so that the liquid remained on the nozzle 11 is taken away, the end part of the nozzle 11 far away from the mixing part 122 after the atomization is finished is ensured not to remain liquid, and the nozzle 11 is prevented from being blocked.

In order to further prevent crystallization of the urea solution, in some alternative designs, as shown in fig. 1, a heat-insulating housing 3 is further included, and the bracket 2 is installed in the heat-insulating housing 3. As shown in fig. 1 and 2 for example, the heat-insulating casing 3 is composed of a heat-insulating jacket 31 and a cover 32, wherein the heat-insulating jacket 31 is an annular sleeve structure, which surrounds and encloses the outer side of the support 2, and the inner diameter of the heat-insulating jacket 31 is larger than the outer diameter of the support 2, so that a certain gap is formed between the heat-insulating jacket 31 and the inner side of the support 2, and the gap is defined as a liquid injection cavity 4 in the application; the peripheral surface of the heat-insulating jacket 31 is also provided with a liquid injection hole 41 and a liquid discharge hole 42 which are communicated with the liquid injection cavity 4, so that liquid can be injected into the liquid injection cavity 4 or discharged from the liquid injection cavity 4. When the anti-freezing solution containing the anti-freezing solution is used as an automobile exhaust treatment system, the anti-freezing solution containing the anti-freezing solution can be arranged near an engine, after being heated by the automobile engine, the anti-freezing solution flows into the liquid injection cavity 4 through the liquid injection hole 41 so as to keep the whole of the bracket 2 warm and heat, and the re-heated anti-freezing solution flows into the liquid injection cavity 4 again, so that the temperature of the bracket 2 and the inside of the bracket can be ensured, and the crystallization of urea solution is avoided.

The two ends of the heat-preserving jacket are respectively sealed by the cover body 32 and the injection device 1; for example, as shown in fig. 3 to 5, the cover 32 may be directly fastened to the top end of the heat insulation jacket 31, and the bottom end of the heat insulation jacket 31 is hermetically connected to the edge of the top surface of the injection device 1. In order not to affect the injection of fluid into the intake valve 21, the intake valve 22 and the blowback valve 23, the inlet of the intake valve 21, the inlet of the intake valve 22 and the inlet of the blowback valve 23 are all located outside the heat-insulating housing 3; for example, the cover 32 is provided with three openings, which are respectively matched with the inlet end of the air inlet valve 21, the inlet end of the liquid inlet valve 22 and the inlet end of the blowback valve 23 in size and corresponding to the positions, and the inlet end of the air inlet valve 21, the inlet end of the liquid inlet valve 22 and the inlet end of the blowback valve 23 all penetrate through the cover 32 and extend to the side, far away from the bracket 2, of the cover 32 so as to facilitate the injection of corresponding fluids into the air inlet valve 21, the liquid inlet valve 22 and the blowback valve 23.

On the basis, the cover body 32 can also press and fix the air inlet valve 21, the liquid inlet valve 22 and the blowback valve 23 in the bracket 2; for example, in one example, the diameters of the inlet end of the air inlet valve 21, the inlet end of the liquid inlet valve 22 and the inlet end of the blowback valve 23 are smaller than those of the valve bodies of the air inlet valve 21, the inlet end of the liquid inlet valve 22 and the inlet end of the blowback valve 23, so that when the inlet end of the air inlet valve 21, the inlet end of the liquid inlet valve 22 and the inlet end of the blowback valve 23 pass through the cover 32, the valve bodies of the three are pressed and fixed in the first mounting hole 24, the second mounting hole 25 and the third mounting hole 26 by the cover 32, and the air inlet valve 21, the liquid inlet valve 22 and the blowback valve 23 are fixed in the bracket 2.

During operation, the antifreeze fluid can be injected into the injection cavity 4 through the injection hole 41, and the heated antifreeze fluid circulates in the injection cavity 4, so that the temperature in the bracket 2 is kept within a required temperature range, and the urea solution is prevented from crystallizing due to low temperature during operation.

On the basis of the above, the application also provides a treatment system for automobile exhaust treatment, which comprises the urea injection device disclosed above, so as to inject urea when the automobile exhaust carries out SCR reaction.

Compared with the existing urea injection device for treating the automobile exhaust, on one hand, the urea injection device can break up urea solution into tiny liquid particles by means of high-speed air flow, so that the urea solution is atomized, the atomized liquid particles can be fully contacted with the automobile exhaust, and the treatment effect of the automobile exhaust is improved; on the other hand, after the urea injection is completed, the blowback gas is injected into the blowback valve 23, so that the urea solution remained in the liquid inlet valve 22 can be blown back and discharged out of the liquid inlet valve 22, and the phenomenon that the residual urea is crystallized in the liquid inlet valve 22 to cause the blockage of the injection device is avoided.

When the tail gas treatment is carried out, the treatment effect is good, meanwhile, the structural integration level is high, and compared with the existing urea injection device, devices such as a urea pump, a reverse pumping pump and the like are not required to be arranged; the functions of spraying, back blowing and the like can be realized through the three valve bodies, and the setting space is reduced.

The foregoing description of the invention has been presented for purposes of illustration and description, and is not intended to be limiting. Several simple deductions, modifications or substitutions may also be made by a person skilled in the art to which the invention pertains, based on the idea of the invention.

Claims

1. A urea injection apparatus, comprising:

2. The urea injection apparatus of claim 1, wherein a blowback valve having an internal channel is further disposed in the bracket, one end of the blowback valve is communicated with one end of the liquid inlet valve, which is used for connecting with a liquid source, the other end of the blowback valve is used for connecting with a second gas source, and the blowback valve can control on-off of the liquid inlet valve and the second gas source.

3. The urea injection apparatus of claim 2, further comprising a thermal insulation housing, wherein the support is disposed within the thermal insulation housing, and wherein the end of the intake valve for receiving gas, the end of the intake valve for receiving liquid, and the end of the blowback valve for receiving gas are all located outside the thermal insulation housing; the heat preservation shell with annotate the liquid chamber has between the lateral surface of support, set up on the heat preservation shell with annotate liquid hole and the flowing back hole of liquid chamber intercommunication.

4. The urea injection apparatus of claim 3, wherein the thermal insulation housing has a thermal insulation jacket and a cover, the cover covering one end of the thermal insulation jacket, the injection apparatus covering the other end of the thermal insulation jacket; the liquid injection cavity is defined by the inner side wall of the heat preservation jacket and the outer side wall of the support, and two ends of the liquid injection cavity are respectively sealed through the cover body and the injection device.

5. The urea injection apparatus of claim 4, wherein the intake valve, and the blowback valve are press-fit secured within the frame by the cover; the inlet valve is used for receiving one end of gas, the liquid inlet valve is used for receiving one end of liquid and the blowback valve is used for receiving one end of gas all pass the lid, and extend to the lid is kept away from the one side of support.

6. The urea injection apparatus of claim 2, wherein the bracket is provided with a first gas channel, a liquid channel and a second gas channel; the air inlet valve is communicated with the air source channel through the first air channel; the liquid inlet valve is communicated with the liquid source channel through the liquid channel; the blowback valve is communicated with the liquid inlet valve through the second gas channel.

7. The urea injection apparatus of claim 2, wherein one or more of the intake valve, the blowback valve, and the intake valve is a solenoid valve.

8. An automobile exhaust treatment system comprising the urea injection apparatus according to any one of claims 1 to 7.

9. A urea solution atomizing method based on the urea injection device according to any one of claims 1 to 7, characterized by comprising the steps of:

10. A urea solution atomizing method based on the urea injection device according to any one of claims 2 to 7, characterized by comprising the steps of: