CN215559043U

CN215559043U - Ammonia generator, aftertreatment system and vehicle

Info

Publication number: CN215559043U
Application number: CN202121577704.7U
Authority: CN
Inventors: 赵振兴
Original assignee: Great Wall Motor Co Ltd
Current assignee: Great Wall Motor Co Ltd
Priority date: 2021-07-12
Filing date: 2021-07-12
Publication date: 2022-01-18
Anticipated expiration: 2031-07-12

Abstract

The utility model provides an ammonia generator which comprises a shell and a plurality of sheet-shaped carriers, wherein the shell is provided with an air inlet and an air outlet, the sheet-shaped carriers are connected in the shell, an air flow channel for communicating the air inlet and the air outlet is formed between the adjacent sheet-shaped carriers, and the surfaces of the sheet-shaped carriers are covered with catalytic coatings. The ammonia gas purification device is simple in structure and convenient to use, urea can be replaced by ammonia gas, the crystallization problem is avoided, and the effective operation of the exhaust device is guaranteed. The utility model also provides an aftertreatment system and a vehicle, which comprise an exhaust device, an ammonia gas nozzle, a reaction gas source and the ammonia generator; the ammonia nozzle is communicated with the exhaust device; in the ammonia generator, an air outlet of the shell is communicated with an ammonia nozzle; the reaction gas source is communicated with the gas inlet of the shell. The direct injection of ammonia gas participates in the tail gas treatment process, crystallization cannot be generated, and the problem that an exhaust device and an ammonia gas nozzle are blocked due to crystallization cannot be caused.

Description

Ammonia generator, aftertreatment system and vehicle

Technical Field

The utility model belongs to the technical field of vehicle tail gas treatment, and particularly relates to an ammonia generator, an after-treatment system and a vehicle.

Background

With the development of the automobile industry, countries have made stricter restrictions on automobile emissions, wherein the limit on the amount of nitrogen oxides is reduced by as much as 82.1%. In order to meet stricter emission regulations, urea liquid is generally sprayed at certain specific positions in an exhaust pipeline, during actual operation, the phenomenon of insufficient urea pyrolysis exists, crystals are generated at a urea nozzle or the exhaust pipeline, the amount of the crystals is gradually increased along with the increase of time, the nozzle is failed, and even the exhaust system is blocked, so that the after-treatment system is failed.

SUMMERY OF THE UTILITY MODEL

The embodiment of the utility model provides an ammonia generator, an aftertreatment system and a vehicle, and aims to avoid the problem that an exhaust device and a spray head are blocked by crystallization while the exhaust treatment effect is ensured.

In order to achieve the purpose, the utility model adopts the technical scheme that:

in a first aspect, there is provided an ammonia generator comprising:

a housing having an air inlet and an air outlet; and

the sheet carriers are connected in the shell, an airflow channel for communicating the air inlet and the air outlet is formed between the adjacent sheet carriers, and the surface of each sheet carrier is covered with a catalytic coating.

With reference to the first aspect, in one possible implementation manner, a plurality of the sheet-like carriers are arranged in parallel with each other.

With reference to the first aspect, in a possible implementation manner, the air inlet end of the outer shell is formed with an expansion section of which the inner diameter gradually expands along the airflow direction, and the air outlet end of the outer shell is formed with a contraction section of which the inner diameter gradually contracts along the airflow direction.

With reference to the first aspect, in a possible implementation manner, the ammonia generator further includes a heater disposed on an outer periphery of the housing, and a heat source of the heater is derived from an exhaust device.

The application provides an ammonia generator can be with reaction gas by the air inlet introduce the shell in, under certain condition, reaction gas produces the ammonia under the effect of the catalytic coating on slice carrier surface to discharge from the gas outlet, and then can provide the ammonia supply for exhaust apparatus. The ammonia generator of this application simple structure, convenient to use, accessible ammonia replace urea, avoid the emergence of crystallization problem, guarantee exhaust apparatus and effectively operate.

In a second aspect, an embodiment of the present invention further provides an aftertreatment system, including:

an exhaust device;

the ammonia nozzle is communicated with the exhaust device;

in the ammonia generator, the air outlet of the housing is communicated with the ammonia gas nozzle; and

and the reaction gas source is communicated with the gas inlet of the shell.

With reference to the second aspect, in a possible implementation manner, the reaction gas source includes a first storage tank, the first storage tank is used for storing a mixed gas of nitrogen and hydrogen, and the aftertreatment system further includes a pressure regulating device, and the pressure regulating device is connected to the first storage tank;

or the reaction gas source comprises two second storage tanks, wherein one of the second storage tanks is used for storing hydrogen, the other one of the second storage tanks is used for storing nitrogen, and the aftertreatment system further comprises a pressure regulating device which is connected with the second storage tank.

With reference to the second aspect, in a possible implementation manner, the ammonia generator further includes a heater, the heater is disposed at the periphery of the housing, a gas passage is formed in the heater, an inlet of the gas passage is communicated with the exhaust device through a gas inlet pipe, an outlet of the gas passage is communicated with the exhaust device through a gas outlet pipe, and a gas inlet end of the gas inlet pipe is located at an upstream of a gas outlet end of the gas outlet pipe.

With reference to the second aspect, in a possible implementation manner, the exhaust device includes an exhaust pipe, and a particulate matter trap and a selective catalytic reduction device that are sequentially connected in series to the exhaust pipe along an airflow direction, and an air inlet end of the air inlet pipe is communicated with an air outlet section of the particulate matter trap.

With reference to the second aspect, in one possible implementation manner, the housing and the sheet-shaped carrier are both metal members.

The application provides an after-treatment system, through adopting foretell ammonia generator, to the gas that introduces in the ammonia generator reaction gas source, produce the ammonia in the ammonia generator, through the ammonia nozzle directly with the ammonia gas injection in the ammonia generator to exhaust apparatus, the ammonia is direct to react with the nitrogen oxide in the tail gas and forms nitrogen gas and water. The post-treatment system provided by the utility model directly sprays ammonia gas to participate in the tail gas treatment process, so that crystallization is avoided, and the problem that an exhaust device and an ammonia gas nozzle are blocked due to crystallization is avoided.

In a third aspect, the embodiment of the utility model further provides a vehicle, which comprises the aftertreatment system.

The application provides a vehicle, through adopting foretell aftertreatment system, the problem of crystalline plug exhaust apparatus and ammonia nozzle is avoided, has reduced aftertreatment system's fault rate to a great extent.

Drawings

FIG. 1 is a schematic structural diagram of an aftertreatment system according to an embodiment of the utility model;

FIG. 2 is a schematic structural diagram of an aftertreatment system according to a second embodiment of the utility model;

FIG. 3 is a schematic front view of an ammonia generator according to a third embodiment of the present invention;

FIG. 4 is a cross-sectional view A-A of FIG. 3;

FIG. 5 is a cross-sectional view B-B of FIG. 3;

fig. 6 is a schematic structural diagram of an ammonia generator and an exhaust device according to a fourth embodiment of the present invention.

Description of reference numerals:

100. an ammonia generator; 110. a housing; 111. an air inlet; 112. an air outlet; 113. an expansion section; 114. a contraction section; 120. a sheet-like support; 130. an air flow channel; 140. a heater; 150. an air inlet pipe; 160. an air outlet pipe;

200. an exhaust device; 210. an exhaust pipe; 220. a particulate matter trap; 230. a selective catalytic reduction device; 240. Lean NO_XA trapping device; 250. an oxygen sensor; 260. a high temperature sensor; 270. a nitrogen-oxygen sensor; 280. a differential pressure sensor;

300. an ammonia gas nozzle;

400. and (4) a reaction gas source.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the utility model and are not intended to limit the utility model.

Referring to fig. 3 to 6 together, the ammonia generator of the present invention will now be described. The ammonia generator 100 comprises a housing 110 and a plurality of sheet-shaped carriers 120, wherein the housing 110 is provided with an air inlet 111 and an air outlet 112; the sheet-shaped carriers 120 are attached inside the housing 110, and an air flow path 130 communicating the air inlet 111 and the air outlet 112 is formed between the adjacent sheet-shaped carriers 120, and the surface of the sheet-shaped carriers 120 is covered with a catalytic coating.

Compared with the prior art, the ammonia generator provided by the embodiment can introduce the reaction gas into the housing 110 through the gas inlet 111, and under certain conditions, the reaction gas generates ammonia gas under the action of the catalytic coating on the surface of the sheet-shaped carrier 120 and is discharged from the gas outlet 112, so as to provide ammonia gas supply for the exhaust device 200. The ammonia generator of this application simple structure, convenient to use, accessible ammonia replace urea, avoid the emergence of crystallization problem, guarantee exhaust apparatus and effectively operate.

In addition, because the surface area of the sheet-shaped carrier is large and the occupied space is small, the arrangement with high density can be carried out, and further, the reaction gas (N) can be greatly increased₂And H₂) The contact area with the catalytic coating makes the reaction more complete.

It should be understood that the "sheet-like carrier" may be a flat sheet, may have a certain curvature, or may be a flat sheet provided with protrusions in the form of waves, saw-teeth, etc., so long as the carrier is substantially in the form of a sheet, and is not specifically described here.

Optionally, the material of the catalytic coating is La₂Ce₂O₇It is 50% lanthana doped ceria.

N₂And H₂In La₂Ce₂O₇Catalytic action of (2) to form NH₃The reaction formula is as follows:

N₂+3H₂→2NH₃

the gaseous ammonia generated by the reaction does not generate crystallization in the tail gas treatment process.

In some embodiments, referring to fig. 4 and 5, a plurality of sheet-like carriers 120 are disposed parallel to each other. This embodiment adopts comparatively simple mode of setting, under the prerequisite of guaranteeing the interior gas circulation performance of shell 110, can make the distribution density of slice carrier 120 obtain improving, and then is favorable to promoting ammonia and generates efficiency.

Of course, the plurality of sheet-shaped carriers 120 may be distributed in a cross manner to form a grid-shaped structure (not shown), which can also provide a larger contact reaction area on the premise of ensuring smooth air inlet and air outlet.

On the basis of the above-mentioned embodiments, referring to fig. 3 to 5, in order to further simplify the overall structure of the ammonia generator 100, the main body of the housing 110 is in a straight cylinder shape, the air inlet 111 faces the air outlet 112, and the sheet-shaped carrier 120 is a straight sheet-shaped member.

In some embodiments, referring to fig. 3 to 6, the inlet end of the housing 110 is formed with an expansion section 113 having an inner diameter gradually expanding in the air flow direction, and the outlet end of the housing 110 is formed with a contraction section 114 having an inner diameter gradually contracting in the air flow direction. The expanding section 113 quickly slows down the flow rate of the gas entering the ammonia generator 100, and prolongs the contact time of the reaction gas and the catalytic coating, so that the reaction is more sufficient; the arrangement of the contraction section 114 increases the pressure of the ammonia gas to be discharged, so that the ammonia gas nozzle 300 can conveniently spray the ammonia gas.

In some embodiments, referring to fig. 6, the ammonia generator 100 further includes a heater 140, the heater 140 is disposed at the outer periphery of the housing 110, and a heat source of the heater 140 is derived from the exhaust device 200.

When using catalytic coatings of certain materials, the temperature increase facilitates the catalytic reaction, for example, when La is used₂Ce₂O₇On the premise of preparing the catalytic coating, the catalytic capability reaches the peak when the temperature reaches 190 ℃, the temperature is continuously increased to be more than 500 ℃, and the catalytic capability is not reduced. The embodiment introduces the high temperature tail gas in the exhaust device into the heater 140, and the ammonia generator 100 is heated by the waste heat of the high temperature tail gas, so that the catalytic capability of the catalytic coating can be effectively improved, the conversion rate of ammonia gas is further improved, and energy required by heating is saved.

Based on the same inventive concept, referring to fig. 1, fig. 2 and fig. 6, the present application further provides an aftertreatment system, which includes an exhaust device 200, an ammonia gas nozzle 300, a reaction gas source 400 and the ammonia generator 100; the ammonia nozzle 300 is communicated with the exhaust device 200; in the ammonia generator 100, the air outlet 111 of the housing 110 is communicated with the ammonia gas nozzle 300; the reactant gas source 400 is in communication with the gas inlet 112 of the housing 110.

Compared with the prior art, the aftertreatment system provided by the embodiment adopts the ammonia generator 100, introduces the gas in the reaction gas source 400 into the ammonia generator 100, generates ammonia gas in the ammonia generator 100, directly sprays the ammonia gas in the ammonia generator 100 into the exhaust device 200 through the ammonia gas nozzle 300, and the ammonia gas directly reacts with the nitrogen oxides in the tail gas to form nitrogen gas and water. The post-treatment system provided by the utility model directly sprays ammonia gas to participate in the tail gas treatment process, so that crystallization is avoided, and the problem that an exhaust device and an ammonia gas nozzle are blocked due to crystallization is avoided.

In some embodiments, the spraying amount of the ammonia gas nozzle 300 can be controlled by the nozzle diameter, and if the ammonia gas sprayed from a certain nozzle diameter can reach the preset spraying amount, the nozzle diameter of the ammonia gas nozzle 300 can be designed to be the value. The diameter of the nozzle of the ammonia nozzle 300 can be selected from the range of 0.2 mm to 0.8mm, and the values of 0.5mm, 0.7mm and the like can be selected within the range, which is not listed.

Of course, the injection amount of the ammonia gas nozzle 300 may be adjusted by controlling the injection pressure, and if the ammonia gas injected at a certain injection pressure can reach a predetermined injection amount, the pressure value may be set as a predetermined pressure value for the ammonia gas injection. The spraying pressure value can be selected from the range of 4bar to 8bar, and the values of 5bar, 6bar and the like can be selected in the range, which is not listed.

In some embodiments, the reaction gas source 400 comprises a first storage tank for storing a mixture of nitrogen and hydrogen, and the aftertreatment system further comprises a pressure regulating device coupled to the first storage tank. In this example, N is used as a reaction gas₂And H₂Storing the mixture in a first storage tank according to a certain molar ratio to form mixed gas. When ammonia gas is to be produced, the mixed gas flows from the first tank to the ammonia generator 100. Optionally, N₂And H₂The molar ratio of (a) to (b) is 1:2 to 1:5, and the requirement of ammonia reaction can be met within the range.

In this embodiment, the regulator can adjust gas output pressure, is convenient for stably take place chemical reaction. It should be noted that the pressure regulating device may be disposed inside the first storage tank, or may be disposed outside the first storage tank, so as to meet the pressure regulating requirement, which is not limited herein.

As another embodiment of the arrangement of the reaction gas source, the reaction gas source 400 includes two second storage tanks, one of the second storage tanks is used for storing hydrogen, the other of the second storage tanks is used for storing nitrogen, and the post-processing system further includes a pressure regulating device, and the pressure regulating device is respectively connected with the second storage tanks. When ammonia gas is required to be generated, the two second storage tanks respectively output N according to the proportion₂And H₂Wherein N is₂And H₂The ratio of (a) to (b) can be controlled by a flow meter. It should be understood that the two second tanks are connected in parallel to ensure that the ammonia generator 100 is fed with gas simultaneously and without interference.

In this embodiment, the regulator can adjust gas output pressure, is convenient for stably take place chemical reaction. It should be noted that the pressure regulating device may be disposed inside the second storage tank, or may be disposed outside the second storage tank, so as to meet the pressure regulating requirement, which is not limited herein.

In some embodiments, referring to fig. 6, the ammonia generator 100 further includes a heater 140, the heater 140 is disposed at the outer periphery of the housing 110, a gas passage is formed in the heater 140, an inlet of the gas passage is communicated with the exhaust device 200 through a gas inlet pipe 150, an outlet of the gas passage is communicated with the exhaust device 200 through a gas outlet pipe 160, and a gas inlet end of the gas inlet pipe 150 is located upstream of a gas outlet end of the gas outlet pipe 160.

Specifically, the gas channels may be distributed in a spiral shape, or may be distributed in other distribution forms, which provide sufficient heat exchange area, and are not listed here.

In some embodiments, referring to fig. 1, 2 and 6, the exhaust device 200 includes an exhaust pipe 210, and a particulate trap 220 and a selective catalytic reduction device 230 sequentially connected in series to the exhaust pipe 210 along an airflow direction, wherein an inlet end of the inlet pipe 150 is communicated with an outlet section of the particulate trap 220. The air outlet section of the particle catcher 220 is a contracting type cone-shaped structure, and the air pressure at the position is relatively high, so that the air can flow into the heater 140 conveniently. In addition, because the gas is treated by the particulate matter catcher 220, black soot in the gas is already caught, so that the blockage of the air inlet pipe 150, the heater 140 and the air outlet pipe 160 by carbon deposition can be effectively avoided, and the influence of the carbon deposition adhesion on the heating efficiency can also be avoided.

On the basis of the above embodiment, referring to fig. 6, in order to ensure the completeness of the exhaust gas treatment, the outlet end of the outlet pipe 160 is connected to the exhaust pipe 210 between the particulate matter trap 220 and the selective catalytic reduction device 230, so as to ensure that all the exhaust gas flowing out of the particulate matter trap 220 is treated by the selective catalytic reduction device 230; meanwhile, through the venturi effect, the gas with a slow flow rate in the outlet pipe 160 can be taken out by the gas with a fast flow rate in the exhaust pipe 210, thereby ensuring the circulation power of the gas in the heater 140.

In addition to the above embodiments, referring to FIG. 2, a lean NO trap 220 is also connected in series upstream of the particulate trap via an exhaust pipe 210_XA trap 240, or an oxygen catalyst (not shown). Lean NO_XAn oxygen sensor 250 and a high temperature sensor 260 are provided upstream of the trap device 240 (or oxygen catalyst) and lean burn NO_XAn oxygen sensor 250, a high-temperature sensor 260 and a nitrogen-oxygen sensor 270 are arranged between the trapping device 240 (or the oxygen catalyst) and the particulate matter trap 220; a high-temperature sensor 260 and a nitrogen-oxygen sensor 270 are arranged between the particulate matter catcher 220 and the selective catalytic reduction device 230; downstream of the selective catalytic reduction device 230 is a nitrogen oxygen sensor 270, and in parallel with the particulate trap 220 is a differential pressure sensor 280.

In the absence of lean-burn NO_XThe arrangement of the oxygen sensor 250, the high temperature sensor 260, and the nitrogen oxide sensor 270 in the exhaust device 200 of the trap device 240 (or the oxygen catalyst) is also similar (see fig. 1), and will not be described again.

In some embodiments, the shell 110 and the sheet-shaped carrier 120 are both metal members, which have high heat conduction efficiency, so that the ammonia generator 100 can rapidly enter a high-temperature state after absorbing heat of the heater 140, thereby improving ammonia gas generation efficiency.

Based on the same inventive concept, the application also provides a vehicle comprising the aftertreatment system.

Compared with the prior art, the vehicle provided by the embodiment has the advantages that the problem that the exhaust device and the ammonia nozzle are blocked by crystals is avoided by adopting the aftertreatment system, and the failure rate of the aftertreatment system is reduced to a great extent.

In some embodiments, the ammonia gas nozzle 300 is an electronically controlled nozzle that is communicatively connected to a vehicle computer (ECU) that controls whether the ammonia gas nozzle 300 is used for injecting.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the utility model, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. An ammonia generator, comprising:

a housing having an air inlet and an air outlet; and

2. An ammonia generator according to claim 1, wherein a plurality of said sheet-like supports are arranged parallel to each other.

3. The ammonia generator of claim 1, wherein the inlet end of the housing is formed with an expansion section having an inner diameter gradually expanding in the gas flow direction, and the outlet end of the housing is formed with a contraction section having an inner diameter gradually contracting in the gas flow direction.

4. The ammonia generator of claim 1, further comprising a heater disposed at an outer periphery of the housing, a heat source of the heater being derived from an exhaust.

5. An aftertreatment system, comprising:

an exhaust device;

the ammonia nozzle is communicated with the exhaust device;

the ammonia generator of any one of claims 1 to 3, wherein the gas outlet of the housing is in communication with the ammonia gas nozzle; and

and the reaction gas source is communicated with the gas inlet of the shell.

6. The aftertreatment system of claim 5, wherein the reactant gas source comprises a first reservoir for storing a mixture of nitrogen and hydrogen, the aftertreatment system further comprising a pressure regulating device coupled to the first reservoir;

7. The aftertreatment system of claim 5, wherein the ammonia generator further comprises a heater disposed at an outer periphery of the housing, a gas passage is formed in the heater, an inlet of the gas passage is communicated with the exhaust device through a gas inlet pipe, an outlet of the gas passage is communicated with the exhaust device through a gas outlet pipe, and a gas inlet end of the gas inlet pipe is located upstream of a gas outlet end of the gas outlet pipe.

8. The aftertreatment system of claim 7, wherein the exhaust device comprises an exhaust pipe, and a particulate trap and a selective catalytic reduction device serially connected to the exhaust pipe in the airflow direction, and an inlet end of the inlet pipe is communicated with an outlet section of the particulate trap.

9. The aftertreatment system of claim 7, wherein the housing and the sheet form carrier are both metal members.

10. A vehicle comprising an aftertreatment system according to any one of claims 5 to 9.