Oxidation catalysis type particle filter
By setting a differentiated coating in the intake channel of the oxidation catalytic particle filter, the front-end carbon deposition problem is solved, the effective regeneration of carbon particles is achieved, the system structure is simplified, and the cost and complexity are reduced.
Patent Information
- Application Number
- CN202422158647.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-03
- Publication Date
- 2025-07-18
- Estimated Expiration
- 2034-09-03
AI Technical Summary
Existing oxidation catalytic particulate filters are prone to carbon accumulation at the front end of the intake passage, which is difficult to eliminate through passive or active regeneration, resulting in insufficient gas flow reaction, insufficient nitrogen dioxide generated, and inability to effectively remove the carbon layer, which may lead to clogging of the gas flow passage.
A differentiated coating is provided in the intake passage, including a first coating and a second coating, the first coating is directly applied to the filter wall, and the second coating is applied to the first coating, both extending axially along the intake passage, the second coating length is smaller than the first coating, and the catalytic particle distribution is differentiated to increase the air flow resistance, promote the deposition of carbon particles on the surface of the first coating and a regeneration reaction occurs.
It effectively avoids carbon deposition at the front end of the intake channel, and thoroughly removes carbon particles through passive and active regeneration mechanisms, improves the airflow processing efficiency, simplifies the system structure, and reduces cost and complexity.
Smart Images
Figure CN223112626U_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the technical field of particulate filters, and particularly relates to an oxidation catalytic particulate filter. Background Art
[0002] The oxidation catalytic particulate filters in the prior art have the disadvantages of easy carbon deposition and difficult regeneration at the front end. The reason is that when the airflow carrying carbon particles flows through such filters, the carbon particles will be trapped and deposited on the surface of the coating. However, for the carbon deposition on the relatively front side, at this time, since the airflow just starts to contact the oxidation catalyst coating, relevant chemical reactions such as NO oxidation and HC ignition do not occur sufficiently. On the one hand, when the engine is running normally, the concentration of NO2 in the airflow at this position is low, and the passive regeneration intensity is weak; on the other hand, when the engine injects fuel for active regeneration, the degree of heat release from the oxidation of HC in the airflow at this position is low, and the temperature is difficult to reach the temperature required for active regeneration, so the active regeneration intensity is weak. That is, for the carbon deposition at the front end of the channel in the oxidation catalytic particulate filters in the prior art, the carbon elimination ability through passive regeneration and active regeneration is very limited. The airflow does not react sufficiently at the front end, and less nitrogen dioxide is generated, which is not conducive to the consumption of carbon by carbon and nitrogen dioxide - passive regeneration, and the consumption of carbon cannot be achieved, resulting in the accumulation of a carbon layer at the front end of the channel, leading to carbon deposition. Even when the carbon loading is too high, the airflow channel may be completely blocked.
[0003] To solve the problem of carbon deposition, a barrel burner is used in the prior art. By making the exhaust gas fully heated in the burner body, the exhaust gas temperature is increased, thereby promoting the active regeneration reaction of the oxidation catalytic particulate filter so that it can eliminate carbon deposition. However, this technology makes the whole system too complex. It is necessary to add additional fuel supply, injection, and ignition systems outside the engine body, resulting in too high system costs and inconvenient space layout. In addition, due to the too high system complexity, some components with failure risks are introduced, resulting in a decrease in reliability. And the method of using the burner to increase the temperature to regenerate and eliminate the carbon deposition in it loses too much in terms of fuel utilization and thermal efficiency. First, the effective utilization of passive regeneration for carbon elimination is lost. Second, since additional fuel is consumed by the burner during active regeneration, the fuel consumption increases. Although it can avoid the problems of easy carbon deposition and difficult regeneration at the front end of the oxidation catalytic particulate filter, it brings many adverse consequences in terms of complexity, reliability, fuel economy, etc., and is not convenient for popularization and use.
[0004] Therefore, a more simple, effective, and convenient particulate filter for avoiding carbon deposition is needed. Summary of the Utility Model
[0005] This application provides an oxidation catalytic particulate filter, which solves the problem of carbon deposition at the front end of the intake channel of the particulate filter by setting a differential coating in the gas channel.
[0006] The technical solution adopted in this application is as follows:
[0007] An oxidation catalytic type particulate filter includes a filter housing, a filter core is arranged inside the housing, a plurality of filter walls are arranged in parallel inside the core, an intake passage is formed between adjacent filter walls, a catalytic oxidation coating coated on the filter walls is arranged inside the intake passage, the catalytic oxidation coating includes a first coating and a second coating arranged in sequence along the radial direction of the intake passage, the first coating and the second coating start from the intake port end of the intake passage, and the length of the second coating is less than the length of the first coating.
[0008] In a preferred implementation manner of an oxidation catalytic type particulate filter, the first coating is directly coated on the filter wall, and the second coating is coated on the first coating.
[0009] In a preferred implementation manner of an oxidation catalytic type particulate filter, the first coating and the second coating are arranged to extend along the axial direction of the intake passage from the intake port of the intake passage, and the second coating is parallel to the first coating.
[0010] In a preferred implementation manner of an oxidation catalytic type particulate filter, the length of the first coating is 3 times or 4 times the length of the second coating.
[0011] In a preferred implementation manner of an oxidation catalytic type particulate filter, the unit density of the first coating is less than the unit density of the second coating.
[0012] In a preferred implementation manner of an oxidation catalytic type particulate filter, the first coating and the second coating are both provided with first catalytic particles, and the second coating is provided with second catalytic particles, and the particle size of the second catalytic particles is less than the particle size of the first catalytic particles.
[0013] In a preferred implementation manner of an oxidation catalytic type particulate filter, the number of catalytic particles in the second coating is greater than the number of catalytic particles in the first coating.
[0014] In a preferred implementation manner of an oxidation catalytic type particulate filter, an exhaust passage is formed between adjacent intake passages, and the air flow sequentially passes through the first coating, the filter wall and enters the exhaust passage.
[0015] In a preferred implementation manner of an oxidation catalytic type particulate filter, plugs are arranged at the ends of each intake passage and the exhaust passage.
[0016] In a preferred implementation manner of an oxidation catalytic type particulate filter, the catalytic particles in the first coating and the second coating are evenly distributed.
[0017] Due to the adoption of the above technical solution, the beneficial effects obtained by this application are as follows:
[0018] (1) By setting the first coating and the second coating, the air flow needs to pass through two catalytic coatings and then be discharged through the filter wall. The flow resistance of the gas is increased with two coatings compared to one coating, making it difficult for the air flow to pass through the triple barriers of the first coating, the second coating, and the filter wall and be discharged. Since the gas has a tendency to flow in the direction of less resistance, the carbon layer will not be deposited inside or on the surface of the coating far from the filter wall, but can only be deposited on the surface of the first coating. However, the gas-phase components in the exhaust gas will still react on the surface and inside of the coating near the inner part of the gas passage, including the reaction of nitric oxide oxidation to form nitrogen dioxide. Therefore, when the exhaust gas flow reaches the area coated only with the first coating in the intake passage, the concentration of nitrogen dioxide in the gas flow is already relatively high, which can cause the passive regeneration reaction of the carbon particles deposited on the first coating, thereby removing them.
[0019] When the engine performs fuel injection active regeneration, similar to the above principle, since there will be no carbon deposition in the front part of the intake passage where the second coating is located, although the front-end temperature is not high enough, there will be no problem of uncleared carbon deposition. And when the air flow reaches the area coated only with the first coating, since the combustion is already relatively sufficient and the exhaust gas temperature is high enough, the active regeneration reaction of the carbon particles deposited on the first coating can occur, thereby removing them more thoroughly.
[0020] (2) Set the first coating directly coated on the filter wall and the second coating coated on the first coating. This coating method is simple and makes the second coating, the first coating, and the filter wall fit together in sequence, realizing the effective blocking of the air flow in the front section of the intake passage.
[0021] (3) The first coating and the second coating are arranged to extend axially along the intake port of the intake passage, and the second coating is parallel to the first coating, which is beneficial to the flow of gas in the intake passage, reduces the air flow detour, and improves the processing efficiency of the exhaust gas flow carrying carbon particles.
[0022] (4) The unit density of the catalytic particles of the second coating is greater than that of the first coating, so the catalytic particles of the second coating are more closely packed, and its pore diameter or porosity is smaller, which is beneficial to strengthening the blocking effect on the air flow at the front end of the intake passage and avoiding carbon deposition at the front end. Description of the Drawings
[0023] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings:
[0024] Figure 1 is the side view of the particulate filter in an embodiment of the present utility model;
[0025] Figure 2 is the left view of the intake passage in an embodiment of the present utility model;
[0026] Figure 3 The right view of the intake passage in an embodiment of the present utility model;
[0027] Figure 4 The internal structure schematic diagram of the first coating in an embodiment of the present utility model;
[0028] Figure 5 The internal structure schematic diagram of the second coating in an embodiment of the present utility model.
[0029] Explanation of the reference numerals in the drawings:
[0030] 1 - Filter wall, 2 - Intake passage, 3 - Exhaust passage, 4 - First coating, 5 - Second coating, 6 - Plug, 7 - Catalytic particles. Detailed implementation manners
[0031] In order to more clearly illustrate the overall concept of the present application, the following will be described in detail by way of examples in conjunction with the drawings in the specification.
[0032] In the following description, many specific details are set forth in order to fully understand the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present application is not limited by the specific embodiments disclosed below. It should be noted that, without conflict, the embodiments of the present application and the features in each embodiment may be combined with each other.
[0033] In addition, in the description of the present application, it should be understood that the orientation or positional relationships indicated by the terms "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.
[0034] In the present application, unless otherwise clearly defined and limited, the terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or a communication connection; it may be directly connected, or indirectly connected through an intermediate medium, and may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.
[0035] In this application, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.
[0036] The solution of this application provides an oxidation catalytic type particulate filter, as Figures 1 to 5 shown, which includes a filter housing. A filter core is provided inside the housing. A plurality of filter walls 1 are arranged in parallel inside the core. An intake passage 2 is formed between adjacent filter walls 1. A catalytic oxidation coating coated on the filter wall 1 is provided inside the intake passage 2. The catalytic oxidation coating includes a first coating 4 and a second coating 5 arranged in sequence along the radial direction of the intake passage 2. The first coating 4 and the second coating 5 start from the intake port end of the intake passage 2, and the length of the second coating 5 is less than the length of the first coating 4.
[0037] The direction indicated by the arrow in the figure is the air flow direction. By setting the first coating 4 and the second coating 5, the air flow needs to pass through two catalytic coatings and then be discharged through the filter wall 1. The flow resistance of the two coatings to the gas is greater than that of one coating, making it difficult for the air flow to pass through the triple barriers of the first coating 4, the second coating 5, and the filter wall 1 and be discharged. Since the gas has a tendency to flow in the direction of less resistance, the carbon layer will not be deposited inside or on the surface of the coating far from the filter wall 1, but can only be deposited on the surface of the first coating 4. However, the gas-phase components in the exhaust gas will still react on the surface and inside of the coating near the inner part of the gas passage, including the reaction of nitric oxide being oxidized to nitrogen dioxide. Therefore, when the exhaust gas flow reaches the area coated only with the first coating 4 in the intake passage 2, the concentration of nitrogen dioxide in the air flow is already relatively high, which can cause the carbon particles deposited on the first coating 4 to undergo a passive regeneration reaction, thereby removing them.
[0038] When the engine performs fuel injection for active regeneration, similar to the above principle, since there will be no carbon deposition in the front part of the intake passage 2 where the second coating 5 is located, although the front-end temperature is not high enough, there will be no problem of carbon deposition that cannot be removed. And when the air flow reaches the area coated only with the first coating 4, since the combustion has been relatively sufficient and the exhaust gas temperature is high enough, the carbon particles deposited on the first coating 4 can undergo an active regeneration reaction, thereby removing them more thoroughly.
[0039] Preferably, as Figure 1 、Figure 2 As shown, the first coating 4 is directly coated on the filter wall 1, and the second coating 5 is coated on the first coating 4. By setting the first coating 4 directly coated on the filter wall 1 and the second coating 5 coated on the first coating 4, this coating method is simple, and it enables the second coating 5, the first coating 4, and the filter wall 1 to fit together in sequence, achieving effective blocking of the airflow in the front section of the intake passage 2.
[0040] In addition, it should be noted that it is also possible to set the second coating 5 directly coated on the filter wall 1 and the first coating 4 coated on the second coating 5, which can also form an obstacle to the front-end airflow. The first coating 4 at the rear end can be arranged to fit the filter wall 1, or other methods can be used for coating and fixing.
[0041] In one embodiment, the first coating 4 and the second coating 5 are arranged to extend axially along the intake port of the intake passage 2, and the second coating 5 is parallel to the first coating 4. This is beneficial to the flow of gas in the intake passage 2, reduces the detour of the airflow, and improves the processing efficiency of the exhaust airflow carrying carbon particles.
[0042] Preferably, the length of the first coating 4 is 3 times or 4 times the length of the second coating 5. If the length of the second coating 5 is too short, the effective blocking effect on the front-end airflow of the intake passage 2 cannot be achieved. If the length of the second coating 5 is too long, it will affect the occurrence of the reaction at the rear end and cause the exhaust efficiency of the airflow in the intake passage 2 to be too slow, resulting in carbon deposition at the rear end.
[0043] It should be noted that the length of the second coating 5 can be set according to the smoke density, exhaust temperature, and concentration of exhaust nitrogen oxides of the engine. The greater the smoke density, the fewer the nitrogen oxides, and the lower the temperature, which means that it is easy to form carbon deposits and difficult to eliminate carbon deposits, and the second coating 5 needs to be set longer.
[0044] In one embodiment, the unit density of the first coating 4 is less than the unit density of the second coating 5. Since the unit density of the catalytic particles 7 in the second coating 5 is greater than that of the first coating 4, the catalytic particles 7 in the second coating 5 are stacked more closely, and its pore size or porosity is smaller, which is beneficial to strengthening the blocking effect on the front-end airflow of the intake passage 2 and avoiding carbon deposition at the front end.
[0045] Preferably, both the first coating 4 and the second coating 5 are provided with first catalytic particles, and the second coating 5 is provided with second catalytic particles, and the particle size of the second catalytic particles is smaller than that of the first catalytic particles. By adding second catalytic particles with a smaller particle size in the second coating 5 compared to the first coating 4, the porosity of the second coating 5 is smaller, which is beneficial to hindering the penetration of the airflow.
[0046] Or, the number of catalytic particles 7 in the second coating 5 is greater than the number of catalytic particles 7 in the first coating 4. This method is beneficial to simply achieve the setting that the unit density of the catalytic particles 7 in the second coating 5 is greater than the unit density of the catalytic particles 7 in the first coating 4.
[0047] In addition, different particle sizes of catalytic particles 7 can be set for the first coating 4 and the second coating 5, so that the second coating 5 has a smaller porosity and a better air flow resistance effect.
[0048] Moreover, regarding the method of differentiating the first coating 4 and the second coating 5, mainly the difference in permeability or penetration ability, on the premise of using the same catalyst particles, setting the second coating 5 to have a greater thickness than the first coating 4 in the air flow direction can be achieved by increasing the viscosity of the slurry during coating; it can also be achieved by adjusting the content of the auxiliary components in the slurry or adjusting the calcination temperature after coating, so that the catalyst particles in the entire second coating 5 are more closely packed, with a smaller porosity. The air flow mainly flows horizontally from the front end to the rear end in the intake passage 2, reducing the vertical or oblique through-wall flow of the air flow at the front end, thereby avoiding the deposition of carbon particles on the second coating 5. Through the second coating 5 with low permeability, the carbon particles will not be deposited at the front end of the intake passage 2 of the oxidation catalytic particle filter, but mainly deposited in the middle and rear ends of the intake passage 2. At this time, the exhaust gas flow already has better gas phase component conditions or temperature conditions, which is conducive to the passive regeneration or active regeneration of carbon particles, thereby effectively avoiding the problem of carbon deposition at the front end of the intake passage 2.
[0049] In one embodiment, as Figure 1 shown, an exhaust passage 3 is formed between adjacent intake passages 2, and the air flow sequentially passes through the first coating 4, the filter wall 1 and enters the exhaust passage 3.
[0050] Furthermore, as Figures 1 to 3 shown, plugs 6 are provided at the ends of each intake passage 2 and the exhaust passage 3. The plugs 6 are used to block the outlet end of the intake passage 2 and the inlet end of the exhaust passage 3 to achieve the guidance of the air flow direction.
[0051] Preferably, as Figure 4 、 Figure 5 shown, the catalytic particles 7 in the first coating 4 and the second coating 5 are evenly distributed. This is beneficial to the uniform flow of the air flow at each position, and at the same time avoids carbon deposition in the parts with fewer catalytic particles.
[0052] Preferably, as Figure 4 、 Figure 5 shown, the catalytic particles in the first coating and the second coating are evenly distributed. This is beneficial to the uniform flow of the air flow at each position, and at the same time avoids carbon deposition in the parts with fewer catalytic particles.
[0053] What is not described in this application can be achieved by adopting or referring to the existing technologies.
[0054] Each embodiment in this specification is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other, and the key point of each embodiment is to illustrate the differences from other embodiments.
[0055] The above description is only for the embodiments of the present application and is not intended to limit the present application. For those skilled in the art, various modifications and changes can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.
Claims
1. An oxidation catalytic type particulate filter, comprising a filter housing, wherein a filter core is provided inside the housing, and is characterized in that, A plurality of filter walls (1) are arranged in parallel in the core body. An intake passage (2) is formed between adjacent filter walls (1). A catalytic oxidation coating coated on the filter wall (1) is provided in the intake passage (2). The catalytic oxidation coating includes a first coating (4) and a second coating (5) arranged in sequence along the radial direction of the intake passage (2). The first coating (4) and the second coating (5) start from the intake port end of the intake passage (2), and the length of the second coating (5) is less than the length of the first coating (4).
2. The oxidation catalytic type particulate filter according to claim 1, characterized in that The first coating (4) is directly coated on the filter wall (1), and the second coating (5) is coated on the first coating (4).
3. The oxidation catalytic type particulate filter according to claim 1 or 2, characterized in that, The first coating (4) and the second coating (5) extend along the axial direction of the intake passage (2) from the intake port of the intake passage (2), and the second coating (5) is parallel to the first coating (4).
4. The oxidation catalytic type particulate filter according to claim 2, characterized in that, The length of the first coating (4) is 3 times or 4 times the length of the second coating (5).
5. An oxidation catalytic type particulate filter according to claim 2, characterized in that, The unit density of the first coating (4) is less than the unit density of the second coating (5).
6. The oxidation catalytic type particulate filter according to claim 5, characterized in that, Both the first coating (4) and the second coating (5) are provided with first catalytic particles, and the second coating (5) is provided with second catalytic particles. The particle size of the second catalytic particles is smaller than the particle size of the first catalytic particles.
7. An oxidation catalytic type particulate filter according to claim 5, characterized in that, The number of catalytic particles (7) in the second coating (5) is greater than the number of catalytic particles (7) in the first coating (4).
8. The oxidation catalytic type particulate filter according to claim 6, characterized in that, An exhaust passage (3) is formed between adjacent intake passages (2). The air flow sequentially passes through the first coating (4), the filter wall (1) and enters the exhaust passage (3).
9. The oxidation catalytic type particulate filter according to claim 8, characterized in that, Plugs (6) are provided at the ends of each intake passage (2) and the exhaust passage (3).
10. The oxidation catalytic type particulate filter according to claim 1, characterized in that, The catalytic particles (7) in the first coating (4) and the second coating (5) are evenly distributed.