Exhaust aftertreatment system

Abstract

The utility model discloses an exhaust after-treatment system, and belongs to the technical field of automobile exhaust after-treatment, the exhaust after-treatment system comprises a urea supply module, a catalytic reaction module and a silencer module, the urea supply module comprises a urea nozzle, and the urea nozzle comprises a liquid injection channel, a liquid outlet channel and a liquid outlet channel; the inlet end of the liquid injection channel is connected with the liquid storage assembly, and the outlet end is connected with the catalytic reaction module; the cooling structure is arranged outside the liquid injection channel, and a cooling cavity is formed between the inner wall of the cooling structure and the outer wall of the liquid injection channel; the exhaust aftertreatment system further comprises an air conditioner module, and the output end of the air conditioner module is connected with the inlet end of the cooling cavity. According to the exhaust aftertreatment system, heat dissipation and cooling can be conducted on the liquid injection channel, the problem that the urea nozzle is blocked due to crystallization produced at the high temperature is avoided, the maintenance cost can be reduced, normal operation of a vehicle is guaranteed, and the user experience is improved.

Description

Technical Field

[0001] The present application relates to the technical field of automobile exhaust after-treatment, and in particular to an exhaust after-treatment system. Background Art

[0002] In recent years, global warming and the greenhouse effect have intensified. To address this, countries have imposed stricter limits on vehicle emissions. Faced with increasingly stringent diesel engine emissions regulations, especially with the gradual implementation of the China VI emission standards, NOx (nitrogen oxide) emission limits have been significantly reduced. Urea selective catalytic reduction (Urea-SCR) technology, due to its high efficiency, selectivity, economy, and sulfur tolerance, has become a key technology for upgrading emissions from domestic light-duty diesel engines. In existing technologies, a urea solution is injected into the SCR catalyst via a urea nozzle. Under the catalytic action of the catalyst, the urea reacts with nitrogen oxides to produce harmless nitrogen, thereby reducing nitrogen oxide emissions. Urea nozzles are installed above the catalyst, where the engine exhaust flows. If a vehicle frequently idles for extended periods or is shut down after operating at high exhaust temperatures, the residual liquid in the nozzle cavity, exposed to high temperatures (greater than 150°C), can form biuret, a hard, water-insoluble crystalline substance.

[0003] The crystallized biuret has high hardness and stable chemical properties and is not easy to decompose, which will clog the injection hole of the urea nozzle. When the vehicle needs to inject urea, the urea nozzle is blocked and cannot be injected. The common practices for dealing with urea nozzle crystallization blockage failures are: first, the user removes the urea nozzle and manually cleans the crystals in the nozzle hole. This solution delays the normal operation of the vehicle and may not be able to completely clean the crystals in the tiny nozzle hole. It cannot eradicate the fault and requires frequent parking for cleaning. Second, directly replace the urea nozzle with a new one. This solution delays the user's normal vehicle operation, generates parts costs and increases the user's cost of use. It cannot eradicate the fault and requires frequent replacement of the urea nozzle. Utility Model Content

[0004] The present application provides an exhaust gas after-treatment system, aiming to solve the problem in the prior art that urea nozzles are easily crystallized and clogged, affecting the normal operation of the vehicle.

[0005] The present application provides an exhaust aftertreatment system, comprising a urea supply module, a catalytic reaction module, and a muffler module. The urea supply module includes a urea nozzle and a liquid storage assembly. The urea nozzle includes a liquid injection channel and a cooling structure. The inlet end of the liquid injection channel is connected to the liquid storage assembly, and the outlet end of the liquid injection channel is connected to the catalytic reaction module. The cooling structure is arranged outside the liquid injection channel, and a cooling cavity is formed between the inner wall of the cooling structure and the outer wall of the liquid injection channel. The exhaust aftertreatment system also includes an air conditioning module, and the output end of the air conditioning module is connected to the inlet end of the cooling cavity.

[0006] Optionally, the cooling chamber is coaxially arranged with the liquid injection channel.

[0007] Optionally, the inlet end of the cooling cavity and the inlet end of the liquid injection channel are arranged on the same side, and the outlet end of the cooling cavity and the outlet end of the liquid injection channel are arranged on the same side.

[0008] Optionally, the inlet end of the cooling cavity and the outlet end of the liquid injection channel are arranged on the same side, and the outlet end of the cooling cavity and the inlet end of the liquid injection channel are arranged on the same side.

[0009] Optionally, a turbulent flow structure is provided in the cooling cavity.

[0010] Optionally, the spoiler structure includes a filter plate, and a plurality of filter holes are provided on the filter plate.

[0011] Optionally, the plurality of filter holes are evenly spaced along the circumference of the filter plate.

[0012] Optionally, a control valve is provided between the output end of the air-conditioning module and the inlet end of the cooling chamber.

[0013] Optionally, the exhaust after-treatment system further includes a control unit, which is connected to the control valve and the urea nozzle respectively, and is configured to control the opening of the control valve according to the injection operation of the urea nozzle.

[0014] Optionally, a cover plate is further provided on the cooling structure, and the cover plate is provided to cover the outlet end of the cooling cavity. One end of the cover plate is rotatably connected to the cooling structure, and the other end of the cover plate is rotated to fit or separate from the cooling structure so that the outlet end of the cooling cavity is closed or opened.

[0015] The advantages of the exhaust after-treatment system over the prior art are:

[0016] The exhaust aftertreatment system includes a urea nozzle, the urea nozzle including a liquid injection channel and a cooling structure; the inlet end of the liquid injection channel is connected to a liquid storage assembly, and the outlet end of the liquid injection channel is connected to a catalytic reaction module; the cooling structure is arranged outside the liquid injection channel, and a cooling cavity is formed between the inner wall of the cooling structure and the outer wall of the liquid injection channel; the exhaust aftertreatment system also includes an air conditioning module, the output end of the air conditioning module is connected to the inlet end of the cooling cavity. The exhaust aftertreatment system described in this application is provided with a cooling structure outside the liquid injection channel of the urea nozzle, and the cold air output by the air conditioning module is diverted to the cooling cavity of the cooling structure, so that the cold air exchanges heat with the high-temperature liquid injection channel to remove heat, thereby cooling the urea nozzle, avoiding the formation of biuret crystals due to excessive temperature, solving the problem of urea nozzle blockage, helping to reduce maintenance costs, ensuring the normal operation of the vehicle, and improving user experience. 2. The exhaust aftertreatment system provided in this application rationally utilizes the air conditioning module of the vehicle air conditioning system to provide a cooling gas source for the urea nozzle, reducing the introduction of external equipment, improving the integration of the whole vehicle, and reducing the cost of cooling gas supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0018] Figure 1 Schematic diagram of the exhaust gas after-treatment system according to one embodiment of the present application;

[0019] Figure 2 This is a structural diagram of a urea nozzle proposed in one embodiment of the present application;

[0020] Figure 3 This is a schematic diagram of the structure of the filter plate in the urea nozzle proposed in one embodiment of the present application.

[0021] Description of reference numerals:

[0022] 1. Urea supply module; 11. Liquid storage assembly; 12. Urea nozzle; 121. Liquid injection channel; 121a. Inlet end of liquid injection channel; 121b. Outlet end of liquid injection channel; 122. Cooling chamber; 122a. Inlet end of cooling chamber; 122b. Outlet end of cooling chamber; 123. Filter plate; 1231. Inner ring; 1232. Filter hole; 124. Cover plate; 21. Air conditioning module; 22. Control valve; 3. Catalytic reaction module; 31. Oxidation catalyst; 32. NOx selective catalytic reduction purifier; 33. Particulate filter; 4. Muffler module; 5. Control unit; 6. Turbocharger; 61. Pressure roller end; 62. Turbine end; 7. Intercooler heat dissipation module; 8. Engine; 9. Air filter. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0024] In related technologies, a urea solution is injected into the SCR catalyst through a urea nozzle. Under the catalytic action of the catalyst, the urea reacts with nitrogen oxides to produce harmless nitrogen, thereby reducing nitrogen oxide emissions. The urea nozzle is installed above the catalyst where the engine exhaust flows. If the vehicle frequently idles for extended periods or is shut down after operating at high exhaust temperatures, the residual liquid in the urea nozzle cavity, exposed to high temperatures (greater than 150°C), can form biuret, a hard, water-insoluble crystal.

[0025] The crystallized biuret has high hardness and stable chemical properties and is not easy to decompose. It will clog the injection hole of the urea nozzle. When the vehicle needs to inject urea, the urea nozzle is blocked and cannot be injected. The common practices for dealing with urea nozzle crystallization blockage failures are: first, the user removes the urea nozzle and manually cleans the crystals in the nozzle hole. This solution delays the normal operation of the vehicle and may not be able to completely clean the crystals in the tiny nozzle hole. It cannot eradicate the fault and requires frequent parking for cleaning. Second, directly replace the urea nozzle with a new one. This solution delays the user's normal vehicle operation, generates parts costs and increases the user's cost of use. It cannot eradicate the fault and requires frequent replacement of the urea nozzle.

[0026] In view of this, an embodiment of the present application provides an exhaust after-treatment system.

[0027] See also Figure 1 and Figure 2An exhaust aftertreatment system includes a urea supply module 1, a catalytic reaction module 3 and a muffler module 4. The urea supply module 1 includes a urea nozzle 12 and a liquid storage assembly 11; the urea nozzle 12 includes a liquid injection channel 121 and a cooling structure, the inlet end 121a of the liquid injection channel is connected to the liquid storage assembly 11, and the outlet end 121b of the liquid injection channel is connected to the catalytic reaction module 3; the cooling structure is arranged outside the liquid injection channel 121; a cooling cavity 122 is formed between the inner wall of the cooling structure and the outer wall of the liquid injection channel 121; the exhaust aftertreatment system also includes an air conditioning module 21, the output end of the air conditioning module 21 is connected to the inlet end of the cooling cavity.

[0028] See also Figure 1 The exhaust after-treatment system includes a urea supply module 1, a catalytic reaction module 3 and a muffler module 4. The urea supply module 1 is used to provide the urea solution required for the reaction to the catalytic reaction module 3. The catalytic reaction module 3 is mainly used to treat the pollutants and particulate matter in the exhaust gas. The muffler module 4 is used to reduce the noise generated by the vehicle exhaust.

[0029] Specifically, the catalytic reaction module 3 includes an oxidation catalyst 31, a NOx selective catalytic reduction purifier 32 and a particulate filter 33. Among them, the main function of the oxidation catalyst 31 is to convert carbon monoxide and hydrocarbons in the exhaust gas into carbon dioxide and water vapor, and at the same time convert nitrogen monoxide in the exhaust gas into nitrogen dioxide, thereby increasing the nitrogen dioxide content in the exhaust gas and promoting the reduction reaction of nitrogen oxides; the function of the NOx selective catalytic reduction purifier 32 is to reduce nitrogen oxides in the exhaust gas into harmless nitrogen and water. This process needs to be achieved by spraying urea solution. The urea solution decomposes at high temperature to produce ammonia. The ammonia reacts with nitrogen oxides under the action of the catalyst, thereby reducing the emission of nitrogen oxides; the particulate filter 33 can capture and store particulate matter in the exhaust gas, and effectively reduce the emission of particulate matter through physical filtration.

[0030] The urea supply module 1 includes a urea nozzle 12 and a liquid storage assembly 11. Figure 2 In the urea nozzle 12, the liquid injection channel 121 serves as a flow channel for the urea solution. The inlet end 121a of the liquid injection channel is connected to the liquid storage assembly 11, which stores the urea solution required for the catalytic reduction reaction. The outlet end 121b of the liquid injection channel is connected to the NOx selective catalytic reduction purifier 32 in the catalytic reaction module 3. When the urea nozzle 12 is in operation, the urea solution in the liquid storage assembly 11 can enter the urea nozzle 12 through the inlet end 121a of the liquid injection channel, flow through the liquid injection channel 121, and then be ejected from the outlet end 121b of the liquid injection channel into the NOx selective catalytic reduction purifier 32 to participate in the catalytic reduction reaction.

[0031] A cooling structure is disposed outside the liquid injection channel 121. A cooling chamber 122 is formed between the inner wall of the cooling structure and the outer wall of the liquid injection channel 121. The cooling chamber 122 has an inlet and an outlet. The inlet 122a of the cooling chamber is connected to the output of the air conditioning module 21 included in the vehicle air conditioning system, while the outlet 122b of the cooling chamber is open to the outside atmosphere. Therefore, cold air output by the air conditioning module 21, as cooling gas, can enter the cooling chamber 122 from the inlet 122a of the cooling chamber, flow within the cooling chamber 122, and finally be discharged into the atmosphere from the outlet 122b of the cooling chamber. While flowing within the cooling chamber 122, the cooling gas exchanges heat with the outer wall of the liquid injection channel 121, thereby reducing the temperature of the urea nozzle 12 and avoiding the problem of biuret crystals forming at high temperatures and clogging the urea nozzle 12.

[0032] The air conditioning module 21 is a working component of the vehicle air conditioning system. Figure 1 The air conditioning module 21 is connected to the engine system's intercooler module 7. The intercooler module 7 dissipates heat and cools the high-temperature air compressed by the turbocharger 6, as well as the condenser of the air conditioning module 21. In this embodiment, a branch line is provided at the output end of the air conditioning module 21. This branch line diverts the cold air output by the air conditioning module 21 to the urea nozzle 12, thereby providing cooling air for the urea nozzle 12.

[0033] The air-conditioning module 21 of the vehicle air-conditioning system includes a compressor. The cold air diverted from the air-conditioning module 21 is pressurized by the compressor and thus has a pressure difference relative to the outside atmosphere. Therefore, driven by the pressure difference, the cooling gas can be directly transported to the cooling chamber 122 of the urea nozzle 12 and finally discharged into the atmosphere.

[0034] Through the above arrangement, a cooling structure is provided outside the liquid injection channel 121, and cooling gas is introduced into the cooling cavity 122 of the cooling structure, so that active cooling of the urea nozzle 12 can be achieved, thereby avoiding the problem of crystallization clogging the urea nozzle 12 at high temperature, ensuring that the urea supply module 1 can normally and stably supply urea solution to the catalytic reaction module 3, thereby ensuring the stable progress of the catalytic reduction reaction, and ultimately meeting the requirements for nitrogen oxide pollution gas emissions.

[0035] Furthermore, the exhaust aftertreatment system provided in this embodiment rationally utilizes the air conditioning module 21 included in the vehicle's air conditioning system, reducing the need for external equipment and significantly reducing air supply costs compared to using external compressed air tanks to supply cooling air. Furthermore, the air conditioning module 21, as part of the vehicle's air conditioning system, provides air with appropriate temperature and humidity within the vehicle. It also serves as a component of the vehicle's exhaust aftertreatment system, providing cooling air for the urea nozzle 12. This achieves integration between the vehicle's air conditioning system and the exhaust aftertreatment system, improving the vehicle's overall integration.

[0036] Optionally, the cooling chamber 122 is coaxially arranged with the liquid injection channel 121 .

[0037] Specifically, to reduce the flow resistance of the urea solution, ensure the injection speed, and facilitate the processing of the urea nozzle 12, the liquid injection channel 121 is generally configured as a linear channel. Preferably, in this embodiment, the liquid injection channel 121 is configured as a cylindrical channel. A cooling structure is arranged around the periphery of the liquid injection channel 121. An annular cooling cavity 122 is formed between the inner wall of the cooling structure and the outer wall of the liquid injection channel 121. The cooling cavity 122 is coaxially arranged with the liquid injection channel 121. As a result, after entering the cooling cavity 122, the cooling gas can be evenly wrapped around the periphery of the liquid injection channel 121, achieving uniform heat exchange.

[0038] Optionally, the inlet end 122a of the cooling cavity and the inlet end 121a of the liquid injection channel are arranged on the same side, and the outlet end 122b of the cooling cavity and the outlet end 121b of the liquid injection channel are arranged on the same side.

[0039] Specifically, such as Figure 2 As shown, in some embodiments, the inlet end 122a of the cooling chamber and the inlet end 121a of the liquid injection channel are arranged on the same side of the urea nozzle 12, that is, Figure 2 On the upper side of the cooling chamber, the outlet end 122b of the cooling chamber and the outlet end 121b of the liquid injection channel are arranged on the same side of the urea nozzle 12, that is, Figure 2 When the urea nozzle 12 is working, the urea solution in the liquid storage assembly 11 enters from the inlet end 121a of the liquid injection channel, flows through the liquid injection channel 121, and is ejected from the outlet end 121b of the liquid injection channel to enter the NOx selective catalytic reduction purifier 32; at the same time, the cold air output by the air conditioning module 21 as cooling gas enters from the inlet end 122a of the cooling chamber, flows along the cooling chamber 122, and is discharged from the outlet end 122b of the cooling chamber. Figure 2As shown, the urea solution flows into the liquid injection channel 121 from the upper side of the urea nozzle 12 and is finally ejected from the lower side of the urea nozzle 12. The cooling gas also flows into the cooling cavity 122 from the upper side of the urea nozzle 12 and is finally discharged from the lower side of the urea nozzle 12. The flow direction of the cooling gas is the same as that of the urea solution.

[0040] Optionally, the inlet end 122a of the cooling cavity and the outlet end 121b of the liquid injection channel are arranged on the same side, and the outlet end 122b of the cooling cavity and the inlet end 121a of the liquid injection channel are arranged on the same side.

[0041] Specifically, in other embodiments, the inlet end 122a of the cooling chamber and the outlet end 121b of the liquid injection channel may be arranged on the same side of the urea nozzle 12, and the outlet end 122b of the cooling chamber and the inlet end 121a of the liquid injection channel may be arranged on the same side of the urea nozzle 12. In this arrangement, the flow direction of the cooling gas is opposite to the flow direction of the urea solution.

[0042] In practical applications, the number of the cooling cavity inlet end 122a and the cooling cavity outlet end 122b can be one or more, and the number of the two can be the same or different. Figure 2 As an example, in this embodiment, the number of the inlet end 122a of the cooling chamber is set to one, which is located on one side of the axis of the liquid injection channel 121; the number of the outlet end 122b of the cooling chamber is set to two, which are symmetrically distributed on both sides of the axis of the liquid injection channel 121.

[0043] Optionally, a turbulent flow structure is provided in the cooling cavity 122 .

[0044] Specifically, in order to further improve the cooling effect, a turbulent flow structure is provided in the cooling cavity 122 . The turbulent flow structure can change the flow of the cooling gas in the cooling cavity 122 , increase the turbulence, and improve the heat exchange efficiency.

[0045] Optionally, the spoiler structure includes a filter plate 123 , and a plurality of filter holes 1232 are provided on the filter plate 123 .

[0046] Specifically, in this embodiment, the spoiler structure includes a filter plate 123, and a plurality of filter holes 1232 are provided on the filter plate 123. After the cooling gas enters the cooling chamber 122, it is blocked by the filter plate 123 and can only pass through the filter holes 1232, so that the turbulence of the cooling gas is increased, which helps to enhance the heat exchange efficiency and improve the cooling effect of the urea nozzle 12.

[0047] In other embodiments, the spoiler structure may also be a grid, a spiral spoiler, a fin, or the like.

[0048] Optionally, the plurality of filter holes 1232 are evenly spaced along the circumference of the filter plate 123 .

[0049] Specifically, in this embodiment, in order to adapt to the structure of the cooling chamber 122, the shape of the filter plate 123 is set to be annular, the inner ring 1231 of the annular filter plate 123 is connected to the outer wall of the liquid injection channel 121, and the outer ring of the annular filter plate 123 is connected to the inner wall of the cooling structure. Figure 3 As shown, the inner ring 1231 of the filter plate 123 is located at the axis of the filter plate 123, and can allow the liquid injection channel 121 to pass through. There are multiple filter holes 1232, and the multiple filter holes 1232 are evenly spaced around the axis of the filter plate 123 along the circumference of the filter plate 123.

[0050] Optionally, in this embodiment, the number of filter plates 123 is set to one, which is arranged in the middle of the cooling chamber 122. In other embodiments, the number of filter plates 123 can also be set to multiple, and multiple filter plates 123 can be distributed at intervals along the axis of the cooling chamber 122.

[0051] Optionally, a cover plate 124 is further provided on the cooling structure, and the cover plate 124 is provided to cover the outlet end 122b of the cooling cavity. One end of the cover plate 124 is rotatably connected to the cooling structure, and the other end of the cover plate 124 is rotated to fit or separate from the cooling structure so that the outlet end 122b of the cooling cavity is closed or opened.

[0052] Specifically, in order to further enhance the heat exchange effect, a cover plate 124 is provided on the cooling structure at a position corresponding to the outlet end 122b of the cooling chamber. The cover plate 124 can completely cover the outlet end 122b of the cooling chamber. In this embodiment, one end of the cover plate 124 is rotatably connected to the outer wall of the cooling structure via a hinge shaft, and the other end of the cover plate 124 is a movable end. A magnetic portion is provided at the position of the cooling structure corresponding to the movable end of the cover plate 124. The cover plate 124 is made of a magnet material. Therefore, the movable end of the cover plate 124 can be adsorbed on the magnetic portion of the cooling structure by rotation, thereby completely closing the outlet end 122b of the cooling chamber. Alternatively, the movable end of the cover plate 124 can also be separated from the magnetic portion by rotation, thereby opening the outlet end 122b of the cooling chamber.

[0053] In this embodiment, the cover plate 124 is in a normally closed state, which can block the cooling gas during the initial stage of its introduction, thereby increasing the residence time of the cooling air within the cooling chamber 122, making heat exchange more efficient and helping to improve the heat exchange effect. As the cooling air continues to be introduced, the cooling gas continues to accumulate in the cooling chamber 122, and the air pressure in the cooling chamber 122 gradually increases. When the air pressure inside the cooling chamber 122 exceeds the adsorption force between the cover plate 124 and the cooling structure, the cover plate 124 will rotate outward under the pressure of the internal air pressure, allowing the cooling gas to be automatically discharged from the outlet end 122b of the cooling chamber.

[0054] Optionally, a control valve 22 is provided between the output end of the air conditioning module 21 and the inlet end 122a of the cooling chamber.

[0055] Specifically, in this embodiment, a branch line is provided at the output end of the air conditioning module 21. This branch line diverts the cold air output by the air conditioning module 21 to the urea nozzle 12, thereby providing cooling gas to the urea nozzle 12. To further facilitate on / off control of the branch line, a control valve 22 is provided on the branch line. The control valve 22 may be a solenoid valve. The control valve 22 is located between the output end of the air conditioning module 21 and the inlet end 122a of the cooling chamber. When the control valve 22 is open, the branch line is in a flow state, allowing the cooling gas output by the air conditioning module 21 to flow into the cooling chamber 122, thereby cooling the urea nozzle 12. When the control valve 22 is closed, the branch line is in a shut-off state, preventing the cooling gas output by the air conditioning module 21 from flowing into the cooling chamber 122. This cuts off the cooling gas source and prevents cooling.

[0056] Optionally, the exhaust after-treatment system further includes a control unit 5 , which is connected to the control valve 22 and the urea nozzle 12 respectively, and is configured to control the opening of the control valve 22 according to the injection operation of the urea nozzle 12 .

[0057] Specifically, the exhaust aftertreatment system also includes a control unit 5, which can control the operating states of the urea nozzle 12 and the control valve 22 according to different operating conditions. Specifically, during urea injection, the control unit 5 controls the urea nozzle 12 to operate and the control valve 22 to open. At this time, urea solution can be injected into the catalyst through the liquid injection channel 121 of the urea nozzle 12. At the same time, the cooling gas output by the air conditioning module 21 can flow into the cooling chamber 122 along the branch pipe, exchanging heat with the liquid injection channel 121 to cool the urea nozzle 12. When urea injection is completed, the control unit 5 controls the urea nozzle 12 to stop operating and close the control valve 22. At this time, the urea solution stops flowing into the liquid injection channel 121. At the same time, the branch pipe is cut off, and the cooling gas output by the air conditioning module 21 can no longer enter the cooling chamber 122, thus preventing cooling.

[0058] The exhaust aftertreatment system described in the embodiment of the present application provides a cooling structure external to the liquid injection channel 121 of the urea nozzle 12 and diverts the cold air output by the air conditioning module 21 to the cooling chamber 122 of the cooling structure. This allows the cold air to exchange heat with the high-temperature liquid injection channel 121, thereby removing heat and achieving active cooling of the urea nozzle 12. This avoids the problem of biuret crystals forming and clogging the urea nozzle 12 due to excessive temperature, helping to reduce maintenance costs, ensure the normal operation of the vehicle, and enhance the user experience. In addition, the rational use of the air conditioning module 21 of the vehicle's air conditioning system provides a source of cooling gas for the urea nozzle 12, reducing the introduction of external equipment, improving the integration of the entire vehicle, and reducing the cost of cooling gas supply.

[0059] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referenced to each other.

[0060] It should also be noted that, in this article, the orientation or position relationship indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. In addition, relational terms such as "first" and "second" are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations, nor can they be understood as indicating or implying relative importance. Moreover, the terms "include", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device that includes a series of elements includes not only those elements, but also includes other elements that are not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, an element defined by the phrase "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or terminal device that includes the element.

[0061] The technical solutions provided by this application are described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of this application. The description of the above embodiments is only intended to help understand this application, and the contents of this specification should not be construed as limiting this application. At the same time, for those skilled in the art, according to this application, there may be various changes in the specific implementation methods and application scopes. It is not necessary and impossible to list all implementation methods here, and obvious changes or modifications derived therefrom are still within the scope of protection of this application.

Claims

1. An exhaust aftertreatment system comprising a urea supply module, a catalytic reaction module, and a muffler module, wherein the urea supply module comprises a urea nozzle and a liquid storage assembly, and is characterized in that: The urea nozzle includes a liquid injection channel and a cooling structure; The inlet end of the liquid injection channel is connected to the liquid storage assembly, and the outlet end of the liquid injection channel is connected to the catalytic reaction module; the cooling structure is arranged outside the liquid injection channel, and a cooling cavity is formed between the inner wall of the cooling structure and the outer wall of the liquid injection channel; The exhaust gas after-treatment system further comprises an air conditioning module, wherein an output end of the air conditioning module is connected to an inlet end of the cooling cavity.

2. The exhaust aftertreatment system according to claim 1, characterized in that: The cooling chamber is coaxially arranged with the liquid injection channel.

3. The exhaust aftertreatment system according to claim 1, characterized in that: The inlet end of the cooling cavity and the inlet end of the liquid injection channel are arranged on the same side, and the outlet end of the cooling cavity and the outlet end of the liquid injection channel are arranged on the same side.

4. The exhaust aftertreatment system according to claim 1, characterized in that: The inlet end of the cooling cavity and the outlet end of the liquid injection channel are arranged on the same side, and the outlet end of the cooling cavity and the inlet end of the liquid injection channel are arranged on the same side.

5. The exhaust aftertreatment system according to claim 1, characterized in that: A turbulent flow structure is arranged in the cooling cavity.

6. The exhaust aftertreatment system according to claim 5, characterized in that: The spoiler structure includes a filter plate, and a plurality of filter holes are provided on the filter plate.

7. The exhaust aftertreatment system according to claim 6, characterized in that: The plurality of filter holes are evenly spaced along the circumference of the filter plate.

8. The exhaust aftertreatment system according to claim 1, characterized in that: A control valve is provided between the output end of the air conditioning module and the inlet end of the cooling cavity.

9. The exhaust aftertreatment system according to claim 8, characterized in that: The exhaust gas after-treatment system further includes a control unit, which is connected to the control valve and the urea nozzle respectively and is configured to control the opening of the control valve according to the injection operation of the urea nozzle.

10. The exhaust after-treatment system according to claim 1, characterized in that: The cooling structure is also provided with a cover plate, which covers the outlet end of the cooling cavity. One end of the cover plate is rotatably connected to the cooling structure, and the other end of the cover plate is rotated to fit or separate from the cooling structure so that the outlet end of the cooling cavity is closed or opened.

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