Engine tail gas treatment device, engine assembly and vehicle

Abstract

The utility model provides an engine tail gas treatment device, an engine assembly and a vehicle, and relates to the technical field of vehicle parts. The engine tail gas treatment device comprises a shell, an inner cavity of the shell serves as a channel for guiding engine tail gas to flow, and a first device and a second device are sequentially arranged in the channel of the shell in the gas flowing direction; the first device comprises a first carrier and a first coating, the first carrier comprises a front section and a rear section, the front section is located in front of the rear section in the gas flowing direction, and the first coating comprises a passive selective catalytic reduction coating coated on the front section and an oxidation catalyst coating coated on the rear section; the second device comprises a second carrier and a second coating coated on the second carrier, and the second coating is an oxidation catalyst coating; wherein the passive selective catalytic reduction coating is used for catalytically reducing nitrogen oxide in engine tail gas, and the oxidation catalyst coating is used for catalytically oxidizing carbon monoxide and hydrocarbon in the engine tail gas.

Description

Technical Field

[0001] This utility model relates to the field of vehicle parts technology, specifically to an engine exhaust gas treatment device, an engine assembly, and a vehicle. Background Technology

[0002] With increasing global energy and environmental pressures, the automotive industry is facing the dual challenges of reducing fuel consumption and emissions. Lean-burn technology, as a high-efficiency engine technology, creates a lean mixture with an air-fuel ratio λ > 1 (i.e., a fuel-to-air ratio higher than the theoretical value of 14.7:1). This significantly improves fuel economy and reduces emissions while maintaining engine power performance. Emissions are reduced while effectively suppressing nitrogen oxides (NOx). Harmful gases such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx) are generated. However, engines using lean-burn technology are not compatible with traditional three-way catalytic converters (TWC). Traditional three-way catalytic converters need to operate under conditions close to the stoichiometric air-fuel ratio (λ≈1, fuel to air ratio close to 14.7:1) to simultaneously and efficiently convert carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx). Under lean-burn conditions, excessively high oxygen content in the exhaust gas inhibits the reduction reaction of traditional three-way catalytic converters, leading to a significant decline in nitrogen oxide conversion efficiency and failure to meet emission requirements.

[0003] In related technologies, to address this issue, Active Selective Catalytic Reduction (ASCR) technology has been applied to lean-burn engine aftertreatment systems. The main method involves injecting urea as a reducing agent to convert nitrogen oxides into harmless nitrogen gas. Urea is mixed with water vapor. However, this method has obvious drawbacks: on the one hand, it requires additional equipment such as a urea injection control unit, urea tank, and urea pump, which significantly increases the system cost; on the other hand, urea is prone to freezing in low-temperature environments, which may cause pipeline blockage and directly affect the long-term reliability of the aftertreatment system. Utility Model Content

[0004] The problem this invention addresses is the design of a low-cost and stable lean-burn engine aftertreatment system.

[0005] To address the aforementioned problems, this utility model provides an engine exhaust gas treatment device, an engine assembly, and a vehicle.

[0006] In a first aspect, this utility model provides an engine exhaust gas treatment device, including a housing, the inner cavity of which serves as a channel for guiding the flow of engine exhaust gas, and a first device and a second device sequentially disposed within the channel along the gas flow direction; the first device includes a first carrier and a first coating, the first carrier including a front section and a rear section, with the front section located in front of the rear section along the gas flow direction, the first coating including a passive selective catalytic reduction coating coated on the front section and an oxidation catalyst coating coated on the rear section; the second device includes a second carrier and a second coating coated on the second carrier, the second coating being an oxidation catalyst coating; wherein, the passive selective catalytic reduction coating is used for catalytic reduction of nitrogen oxides in engine exhaust gas, and the oxidation catalyst coating is used for catalytic oxidation of carbon monoxide and hydrocarbons in engine exhaust gas.

[0007] Optionally, the second carrier is a filter carrier.

[0008] Optionally, it also includes a differential pressure sensor, wherein the high-pressure tap and the low-pressure tap of the differential pressure sensor are respectively located on the intake side and the exhaust side of the second device;

[0009] And / or, the second carrier has a cylindrical honeycomb structure.

[0010] Optionally, the passive selective catalytic reduction coating comprises an FER-type molecular sieve material.

[0011] Optionally, the first carrier has a cylindrical honeycomb structure and is divided into two sections along the axial direction: the front section and the rear section; the length of the front section accounts for no less than 70%.

[0012] Optionally, the first device and the second device are spaced apart.

[0013] Optionally, the housing includes an air inlet guide shroud, and an airflow baffle is provided inside the air inlet guide shroud. One end of the airflow baffle faces the air inlet end of the air inlet guide shroud and is sealed to the inner wall of the air inlet guide shroud, while the other end faces the air outlet end of the air inlet guide shroud and is spaced apart from the inner wall of the air inlet guide shroud.

[0014] Optionally, the housing further includes a housing body, in which the first device and the second device are disposed. The air inlet of the housing body is sealed to the large-diameter end of the air inlet guide shroud. The housing body and the airflow baffle are arranged coaxially, and the diameter of the airflow baffle is not greater than the diameter of the cylindrical carrier of the first device.

[0015] Secondly, this utility model provides an engine assembly, including an engine and the aforementioned engine exhaust treatment device, wherein the engine exhaust gas is discharged into the atmosphere after passing through the engine exhaust treatment device.

[0016] Thirdly, this utility model provides a vehicle including the aforementioned engine assembly.

[0017] The beneficial effects of this engine exhaust gas treatment device are:

[0018] By sequentially arranging a first device and a second device along the gas flow direction within the channel of the housing, and coating the front section of the first carrier with a passive selective catalytic reduction coating, the nitrogen oxides are selectively reduced to harmless nitrogen gas through a catalytic reaction using naturally occurring hydrocarbons and other reducing gases in the exhaust gas. An oxidation catalyst coating is then coated on the second carrier, allowing the remaining carbon monoxide and hydrocarbons to be oxidized by the oxidation catalyst coating when the exhaust gas treated by the first device enters the second device, thus purifying nitrogen oxides, carbon monoxide, and hydrocarbons. Compared to related technologies, this method eliminates the need for additional urea injection control units, urea tanks, urea pumps, and other equipment, significantly reducing system costs. It also avoids problems such as urea freezing at low temperatures and pipeline blockage, greatly improving the long-term reliability of the aftertreatment system.

[0019] Furthermore, the rear section of the first carrier is coated with an oxidation catalyst coating, which can oxidize a small portion of carbon monoxide and hydrocarbons. The heat generated by the oxidation process heats the front section of the carrier, allowing for a rapid increase in the temperature of the passive selective catalytic reduction coating on the front section during engine cold starts. This ensures efficient purification of nitrogen oxides during cold starts, meeting emission requirements and addressing the low efficiency of passive selective catalytic reduction coatings at low temperatures. Placing the second device after the first device and the front section before the rear section prevents premature oxidation of reducing gases (hydrocarbons, etc.), ensuring the reduction efficiency of nitrogen oxides in the front section of the first device. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the installation structure of the engine exhaust gas treatment device in the embodiments of this application.

[0021] Figure 2 This is a cross-sectional schematic diagram of the engine exhaust gas treatment device in the embodiments of this application.

[0022] Figure 3 This is a schematic diagram of the large-diameter end structure of the air intake guide shroud of the engine exhaust gas treatment device in the embodiments of this application.

[0023] Figure 4 This is a schematic diagram of the airflow baffle structure of the engine exhaust gas treatment device in the embodiments of this application.

[0024] Explanation of reference numerals in the attached drawings: 1. Housing; 11. Inlet shroud; 12. Airflow baffle; 121. Connecting rib; 13. Housing body; 14. Inlet bend; 15. Outlet shroud; 16. Straight pipe; 2. First component; 21. Front section; 22. Rear section; 3. Second component; 4. Differential pressure sensor. Detailed Implementation

[0025] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Although some embodiments of this utility model are shown in the drawings, it should be understood that this utility model can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this utility model. It should be understood that the drawings and embodiments of this utility model are for illustrative purposes only and are not intended to limit the scope of protection of this utility model.

[0026] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first," "second," etc., mentioned in this utility model are only used to distinguish different devices, modules, or units, and are not used to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0027] It should be noted that the terms "one" and "multiple" used in this utility model are illustrative rather than restrictive. Those skilled in the art should understand that, unless explicitly stated otherwise in the context, they should be understood as "one or more". "Several" refers to one or more "one or more".

[0028] Terminology Explanation:

[0029] Passive Selective Catalytic Reduction (P-SCR) is a technique that uses hydrocarbons (HC) in engine exhaust as a reducing agent to selectively catalytically reduce nitrogen oxides (NOx). The external purification technology of the machine is different from that of active selective catalytic reduction (ASCR), which requires additional urea injection.

[0030] A particulate filter (PF) is a purification device used to capture particulate matter from engine or industrial emissions, and is widely used in automotive exhaust treatment, industrial waste gas treatment, and other fields. Its core function is to reduce particulate matter emissions through physical interception or catalytic oxidation, protecting the environment and human health. It mainly includes gasoline engine particulate filters (GPF) and diesel engine particulate filters (DPF).

[0031] OC is an abbreviation for Oxidation Catalyst, a key functional coating in engine exhaust aftertreatment systems. Its core function is to catalyze the oxidation of gaseous pollutants such as carbon monoxide (CO) and hydrocarbons (HC).

[0032] like Figure 1 and Figure 2 As shown, this utility model embodiment provides an engine exhaust gas treatment device, including a housing 1. The inner cavity of the housing 1 serves as a channel for guiding the flow of engine exhaust gas. A first device 2 and a second device 3 are sequentially arranged in the channel of the housing 1 along the gas flow direction. The first device 2 includes a first carrier and a first coating. The first carrier includes a front section 21 and a rear section 22, and the front section 21 is located in front of the rear section 22 along the gas flow direction. The first coating includes a passive selective catalytic reduction coating coated on the front section 21 and an oxidation catalyst coating coated on the rear section 22. The second device 3 includes a second carrier and a second coating coated on the second carrier. The second coating is an oxidation catalyst coating. The passive selective catalytic reduction coating is used to catalytically reduce nitrogen oxides in the engine exhaust gas, and the oxidation catalyst coating is used to catalytically oxidize carbon monoxide and hydrocarbons in the engine exhaust gas.

[0033] In this embodiment, a first device 2 and a second device 3 are sequentially arranged along the gas flow direction within the channel of the housing 1. A passive selective catalytic reduction coating is applied to the front section 21 of the first carrier. The reducing gases, such as hydrocarbons naturally present in the exhaust gas, undergo a catalytic reaction to selectively reduce nitrogen oxides to harmless nitrogen. An oxidation catalyst coating is applied to the second carrier, so that when the exhaust gas treated by the first device 2 enters the second device 3, the remaining carbon monoxide and hydrocarbons are oxidized by the oxidation catalyst coating, achieving purification of nitrogen oxides, carbon monoxide, and hydrocarbons. Compared with related technologies, this method eliminates the need for additional urea injection control units, urea tanks, urea pumps, and other equipment, significantly reducing system costs. It also avoids problems such as urea freezing at low temperatures and pipeline blockage, greatly improving the long-term reliability of the aftertreatment system. The first device 2 is the passive selective catalytic reduction (P-SCR).

[0034] Furthermore, the rear section 22 of the first carrier is coated with an oxidation catalyst coating, which can oxidize a small portion of carbon monoxide and hydrocarbons. The heat generated by the oxidation process heats the front section 21 of the carrier, allowing for a rapid increase in the temperature of the passive selective catalytic reduction coating on the front section 21 during engine cold starts. This ensures efficient purification of nitrogen oxides during cold starts, meeting emission requirements and addressing the low efficiency of the passive selective catalytic reduction coating under low-temperature conditions. Positioning the second device 3 after the first device 2 and the front section 21 before the rear section 22 prevents premature oxidation of reducing gases (hydrocarbons, etc.), ensuring the reduction efficiency of nitrogen oxides by the front section 21 of the first device 2.

[0035] Furthermore, the heat generated by the oxidation catalyst coating on the rear section 22 of the first carrier during the oxidation reaction can also heat the exhaust gas flowing to the second carrier: on the one hand, it can increase the working temperature of the catalyst coating on the second carrier and optimize its catalytic reaction effect; on the other hand, it can make up for the structural defect of the second carrier being far away from the engine exhaust port and thus the low exhaust gas temperature, ensuring that the second carrier is always in the high-efficiency catalytic range.

[0036] It should be noted that in this application, "front and back along the gas flow direction" are defined as follows: the component or part through which the gas flows first is "front", and the component or part through which the gas flows last is "back".

[0037] Optionally, the second carrier is a filter carrier.

[0038] In this optional embodiment, the second carrier of the second device 3 is a filter carrier, that is, it has the function of capturing particulate matter. When the engine exhaust flows through the second device 3, the filter carrier of the second device 3 captures particulate matter in the exhaust through interception and diffusion mechanisms, thereby achieving full-dimensional purification of nitrogen oxides, carbon monoxide, hydrocarbons and particulate matter in the engine exhaust.

[0039] It should be noted that when the second carrier is a filter-type carrier, that is, the oxidation catalyst (OC) coating is applied to the surface of the particulate filter (PF) carrier, such as the oxidation catalyst coating being applied to the surface of the carrier of a gasoline engine particulate filter, a gasoline particulate filter (CGPF) is formed, which has the functions of oxidizing gaseous pollutants and capturing particulate matter.

[0040] Furthermore, whether the second carrier of the second device 3 is a filter-type carrier can be selected based on the engine's fuel. For example, the exhaust gas from hydrogen and ammonia fuel engines contains almost no particulate matter, so the second carrier does not need to be a filter-type carrier when using this engine exhaust treatment device; the exhaust gas from gasoline fuel engines contains a large amount of particulate matter, so the second carrier needs to be a filter-type carrier when using this engine exhaust treatment device; the particulate matter content in the exhaust gas from methanol fuel engines is significantly lower than that of gasoline engines, so if the engine exhaust treatment device is used in scenarios with stringent emission standards, the second carrier needs to have a filter-type structure, but if it is only used in scenarios with low emission standards, the second carrier does not need to have a filter-type structure.

[0041] Optionally, such as Figure 2 As shown, the engine exhaust gas treatment device also includes a differential pressure sensor 4, with the high-pressure tap and low-pressure tap of the differential pressure sensor 4 located on the intake side and exhaust side of the second device 3, respectively.

[0042] In this optional embodiment, by setting the high-pressure port and low-pressure port of the differential pressure sensor 4 on the intake side and exhaust side of the second device 3 respectively, the differential pressure between the front and rear ends of the carrier of the second device 3 is monitored in real time, providing a signal basis for triggering and terminating the regeneration of the filter carrier of the second device 3. Specifically, when the accumulation of particulate matter in the second device 3 causes the exhaust pressure difference to reach a set threshold, the exhaust waste heat and the oxidative exothermic reaction of the oxidizing catalyst coating can be used to cause the particulate matter to burn and decompose, realizing the autonomous regeneration of the particulate matter capture function of the second device 3 and continuously maintaining the particulate matter capture and purification capacity.

[0043] Optionally, the second carrier has a cylindrical honeycomb structure.

[0044] In this optional embodiment, the second carrier adopts a conventional cylindrical honeycomb design, with the carrier material often being cordierite or silicon carbide. The interior is filled with parallel micro-honeycomb channels, with the ends of the channels alternately sealed to force exhaust gas through the pore walls, thus achieving particulate matter filtration. During coating, a uniform, robust, and low-resistance catalytic coating is formed on the inner wall of the honeycomb channels.

[0045] Optionally, the passive selective catalytic reduction coating includes FER-type molecular sieve materials.

[0046] In this optional embodiment, to further address the technical challenge of low nitrogen oxide conversion efficiency in the aftertreatment system during the engine's low-temperature cold start phase, the passive selective catalytic reduction coating preferably employs FER-type molecular sieve material. Its core advantage is that FER molecular sieves possess excellent small molecule adsorption capacity, and at low temperatures... , It has a high adsorption capacity and can quickly adsorb and store nitrogen oxides in the exhaust gas during the cold start phase. When the exhaust temperature rises, the adsorbed nitrogen oxides are gradually desorbed and react at the active sites of the catalyst, thus avoiding the direct emission of nitrogen oxides during the cold start phase.

[0047] FER is a unified topological structure code defined by the International Zeolite Association (IZA), corresponding to a family of molecular sieves based on natural magnesium-alkali zeolite. This family includes not only natural magnesium-alkali zeolite minerals but also synthetic molecular sieve members with FER topological structures, such as ZSM-35 and ZSM-21, all of which inherit the core structural features of magnesium-alkali zeolite. Therefore, FER-type molecular sieves belong to the FER topological structure branch of the zeolite molecular sieve family, and magnesium-alkali zeolite is the natural parent material and core representative of this branch.

[0048] Optionally, the carrier of the first device 2 has a cylindrical honeycomb structure and is divided into two segments along the axial direction: a front segment 21 and a rear segment 22; the length of the front segment 21 accounts for no less than 70%.

[0049] In this optional embodiment, the first carrier is a conventional cylindrical honeycomb structure, which has a large surface area and low flow resistance, and is easy to arrange in a cylindrical channel, with engine exhaust gas flowing along the axial direction of the first device 2. The carrier is divided into two sections along the axial direction: a front section 21 and a rear section 22. These two sections are coated with different functional coatings through a segmented coating process, and the length of the front section 21 accounts for no less than 70% of the total axial length of the carrier (i.e., the length ratio of the front section 21 to the rear section 22 is ≥7:3), ensuring that the passive selective catalytic reduction reaction proceeds sufficiently. For example, the axial length ratio of the front section 21 to the rear section 22 of the carrier in the first device 2 can be selected as 9:1, 8:2, or 7:3, where length is defined as the axial path of the gas flowing through the carrier.

[0050] In addition, during the fabrication of the carrier for the first device 2: firstly, the rear functional area (rear section 22) of the carrier is shielded using a shielding fixture, leaving space for the oxidation catalyst coating. The front functional area (front section 21) is then dip-coated, spray-coated, or coated with a passive selective catalytic reduction (SCR) coating. After drying and curing, the shielding fixture is removed. Next, the coated front section 21 is protected using the same shielding method, and the rear section 22 is coated with the oxidation catalyst coating. Finally, the entire process is completed through firing. This ensures that the coatings for each functional area are formed independently without cross-contamination, and that the SCR coating is always located in the front area of ​​the carrier along the exhaust flow direction, while the oxidation catalyst coating is located in the rear area. During coating, a uniform, robust, and low-resistance catalytic coating is formed on the inner wall of the honeycomb channels.

[0051] It should be noted that although both the first and second carriers are cylindrical honeycomb structures, they differ in some aspects. The second carrier employs a wall-flow structure: adjacent channels are alternately sealed at both ends with ceramic plugs (e.g., channel A is sealed on the left and open on the right, and adjacent channel B is open on the left and sealed on the right), forcing the exhaust gas to pass through the porous wall between the channels to be discharged. Particles are intercepted on the inlet side of the wall, achieving filtration. The first carrier, on the other hand, has a straight-through structure: the channels are unblocked, allowing exhaust gas to flow directly in from one end and out from the other. The key is to ensure that the exhaust gas makes full contact with the catalytic coating on the inner wall of the channels.

[0052] Optionally, such as Figure 2 As shown, the first device 2 and the second device 3 are arranged at intervals.

[0053] In this optional embodiment, the carriers of the first device 2 and the second device 3 are mostly cylindrical honeycomb structures, but the size and arrangement of the channels are different. Therefore, they are arranged alternately so that the engine exhaust gas can flow smoothly through them.

[0054] Optionally, such as Figure 1-4 As shown, the housing 1 includes an air inlet guide shroud 11, and an airflow baffle 12 is provided inside the air inlet guide shroud 11. One end of the airflow baffle 12 faces the air inlet end of the air inlet guide shroud 11 and is sealed to the inner wall of the air inlet guide shroud 11, while the other end faces the air outlet end of the air inlet guide shroud 11 and is spaced apart from the inner wall of the air inlet guide shroud 11.

[0055] In this optional embodiment, the intake end deflector 11 typically adopts a classic conical structure design, which guides the engine exhaust gas towards the first device 2. Considering that a gasket or similar structure is usually provided between the carrier of the first device 2 and the inner wall of the housing 1 for assembly and fixation, i.e., the airflow channel is blocked by the gasket in the edge area near the inner wall of the housing 1, this application innovatively proposes a design scheme to add an airflow baffle 12 inside the intake end deflector 11. Specifically, one end of the airflow baffle 12 is sealed to the inner wall of the intake end deflector 11, while the other end is kept at a certain distance from the inner wall. Such an airflow baffle 12 can guide the engine exhaust gas to concentrate and flow in the central area of ​​the intake end deflector 11, thereby ensuring that more exhaust gas can be accurately guided to the carrier area of ​​the first device 2, and fully contact and react with the catalytic coating coated on the carrier surface, thereby significantly improving the exhaust gas purification efficiency; during low-temperature cold start, it can also prevent exhaust gas temperature diffusion, further increasing the rate of temperature rise of the carrier of the first device 2. Furthermore, this design effectively reduces the airflow towards the outer liner area of ​​the first device 2 carrier, preventing local turbulence and thus significantly reducing the flow resistance of exhaust gas within the housing 1, ensuring a smoother and more unobstructed engine exhaust process. Preferably, as... Figure 3 and Figure 4 As shown, the airflow baffle 12 has a cylindrical structure.

[0056] Optionally, such as Figure 2 and Figure 4 As shown, the outer wall of the airflow baffle 12 is provided with a connecting rib 121, which is used to connect the airflow baffle 12 and the inner wall of the air inlet guide shroud 11. Specifically, the airflow baffle 12 is cylindrical, and the outer wall is provided with a right-angled triangular connecting rib 121. The side of the connecting rib 121 with one right angle is in contact with the airflow baffle 12, and the side with the hypotenuse is in contact with the inner wall of the air inlet guide shroud 11.

[0057] Optionally, such as Figure 2 As shown, the housing 1 also includes a housing body 13, in which a first device 2 and a second device 3 are disposed. The air inlet of the housing body 13 is sealed to the large-diameter end of the air inlet guide shroud 11. The housing body 13 is coaxially arranged with the airflow baffle 12, and the diameter of the airflow baffle 12 is not greater than the diameter of the cylindrical carrier of the first device 2.

[0058] In this optional embodiment, the shell body 13 is typically designed as a cylindrical structure, which can precisely adapt to the cylindrical carrier installation requirements of the first device 2 and the second device 3, ensuring that the devices are firmly fixed. By arranging the shell body 13 and the airflow baffle 12 coaxially, and combining the size limitation that "the diameter of the airflow baffle 12 is ≤ the diameter of the carrier of the first device 2", the exhaust gas guided and gathered by the air inlet guide shroud 11 can be precisely introduced into the carrier reaction area of ​​the first device 2 along the axial direction through the airflow baffle 12, avoiding the airflow from deviating from the carrier range or flowing towards the carrier edge, further ensuring sufficient contact between the exhaust gas and the catalytic coating, while reducing the flow resistance caused by local airflow disturbance.

[0059] In addition, such as Figure 2 As shown, the housing 1 also includes an intake bend 14, an exhaust shroud 15, and an exhaust straight pipe 16, etc., and the components are connected by a sealed connection to form a complete exhaust gas flow channel. One end of the intake bend 14 is provided with a mounting flange for fixed connection with the turbocharger; the other end is sealed to the small-diameter end of the intake shroud 11 to ensure no exhaust gas leakage. The exhaust shroud 15 has a conical structure, with its large-diameter end sealed to the exhaust port of the housing body 13, and its small-diameter end fixedly connected to the exhaust straight pipe 16. The other end of the exhaust straight pipe 16 is connected to the exhaust pipe, and the conical guide design reduces the exhaust gas flow resistance.

[0060] To accommodate the low exhaust temperature of lean-burn engines, the outer wall of housing 1 can be wrapped with insulation cotton to reduce heat loss from exhaust gases, help the passive selective catalytic reduction coating quickly reach its optimal operating temperature, and ensure catalytic purification efficiency under low-temperature conditions.

[0061] like Figure 1As shown, another embodiment of this utility model provides an engine assembly, including an engine and the aforementioned engine exhaust treatment device. The engine exhaust gas flows through the engine exhaust treatment device before being discharged into the atmosphere. The specific technical improvements and effects of the engine assembly are the same as those of the aforementioned engine exhaust treatment device, and will not be repeated here.

[0062] Another embodiment of this utility model provides a vehicle including the aforementioned engine assembly. The technical improvements and effects of the vehicle are the same as those of the engine assembly, and will not be described again.

[0063] Although the present invention has been disclosed above, its protection scope is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the protection scope of the present invention.

Claims

1. An engine exhaust gas treatment device, characterized in that, The device includes a housing (1), the inner cavity of which serves as a channel for guiding the flow of engine exhaust gas. A first device (2) and a second device (3) are sequentially arranged in the channel of the housing (1) along the gas flow direction. The first device (2) includes a first carrier and a first coating. The first carrier includes a front section (21) and a rear section (22), and the front section (21) is located in front of the rear section (22) along the gas flow direction. The first coating includes a passive selective catalytic reduction coating coated on the front section (21) and an oxidation catalyst coating coated on the rear section (22). The second device (3) includes a second carrier and a second coating coated on the second carrier, wherein the second coating is an oxidation catalyst coating; wherein the passive selective catalytic reduction coating is used for catalytic reduction of nitrogen oxides in engine exhaust gas, and the oxidation catalyst coating is used for catalytic oxidation of carbon monoxide and hydrocarbons in engine exhaust gas.

2. The engine exhaust gas treatment device according to claim 1, characterized in that, The second carrier is a filter-type carrier.

3. The engine exhaust gas treatment device according to claim 2, characterized in that, It also includes a differential pressure sensor (4), the high pressure tap and the low pressure tap of the differential pressure sensor (4) are respectively located on the intake side and exhaust side of the second device (3); And / or, the second carrier has a cylindrical honeycomb structure.

4. The engine exhaust gas treatment device according to claim 1, characterized in that, The passive selective catalytic reduction coating includes FER-type molecular sieve materials.

5. The engine exhaust gas treatment device according to claim 1, characterized in that, The first carrier has a cylindrical honeycomb structure and is divided into two sections along the axial direction: the front section (21) and the rear section (22); the length of the front section (21) is not less than 70%.

6. The engine exhaust gas treatment device according to claim 1, characterized in that, The first device (2) and the second device (3) are spaced apart.

7. The engine exhaust gas treatment device according to claim 1, characterized in that, The housing (1) includes an air inlet guide shroud (11), and an airflow baffle (12) is provided inside the air inlet guide shroud (11). One end of the airflow baffle (12) faces the air inlet end of the air inlet guide shroud (11) and is sealed to the inner wall of the air inlet guide shroud (11). The other end faces the air outlet end of the air inlet guide shroud (11) and is spaced apart from the inner wall of the air inlet guide shroud (11).

8. The engine exhaust gas treatment device according to claim 7, characterized in that, The housing (1) further includes a housing body (13), in which the first device (2) and the second device (3) are disposed. The air inlet of the housing body (13) is sealed to the large-diameter end of the air inlet guide shroud (11). The housing body (13) is coaxially arranged with the airflow baffle (12), and the diameter of the airflow baffle (12) is not greater than the diameter of the cylindrical carrier of the first device (2).

9. An engine assembly, characterized in that, It includes an engine and an engine exhaust treatment device as described in any one of claims 1-8, wherein the exhaust gas from the engine is discharged into the atmosphere after passing through the engine exhaust treatment device.

10. A vehicle, characterized in that, Includes the engine assembly as described in claim 9.

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