CN103670605B - A kind of diesel engine and particulate matter trap regenerating unit thereof - Google Patents

Abstract

The invention discloses a particulate trap regeneration device, comprising: a particulate trap; an oxidation catalytic converter; the particulate trap is vertically arranged vertically to the oxidation catalytic converter; An airflow swirling device (2); the airflow swirling device (2) is provided with a particle collector (3). The device can ensure that the particle load inside the DPF is always in a low state, and it can meet the requirements of the post-treatment system without using the DPF active regeneration system and manual dust removal. The invention also discloses a diesel engine provided with the regeneration device.

Description

A kind of regeneration device of diesel engine and particle trap

technical field

The invention relates to the technical field of engines, in particular to a particulate matter trap regeneration device applied to a diesel engine exhaust gas treatment system. The invention also relates to a diesel engine provided with said regeneration device.

Background technique

In recent years, as my country has paid more and more attention to environmental protection, more stringent emission control regulations have been introduced one after another. The control of particulate pollutants emitted by automobile diesel engines has become the main issue for the current automobile emission to achieve Euro VI.

The exhaust particulate matter of a diesel engine mainly contains three components: unburned soot (Soot), organic soluble substances (SolubleOrganicFractions, SOF) adsorbed on the surface, and sulfate, and most of the particulate emissions are tiny particles of carbon and carbides made up of.

DPF (Diesel Particulate Filter) is a particulate filter that eliminates particulates (PM) in diesel engine exhaust. It mainly filters and captures particulates in diesel engine exhaust through diffusion, deposition and impact mechanisms, and the capture efficiency can reach more than 90%.

DOC (DieselOxidationCatalysis) is a particle oxidation catalytic converter, which is coated with a noble metal catalyst (such as Pt, etc.) These substances can oxidize with the oxygen in the tail gas at a lower temperature and finally convert into CO ₂ and H ₂ O.

The combination of DPF and DOC can constitute a particulate matter capture system, and its basic working principle is: when the exhaust gas of a diesel engine flows through the DOC, at a temperature of 200-400°C, CO and HC are first almost completely oxidized into CO ₂ and H ₂ O, and NO is converted into NO ₂ at the same time. After the exhaust gas comes out of the DOC and enters the DPF, the particles are trapped in the filter element of the filter body, and the cleaner exhaust gas is discharged into the atmosphere.

As the working time increases, more and more particles accumulate on the DPF filter body, which not only affects the filter effect of the trap, but also increases the exhaust back pressure, thereby affecting the ventilation and combustion of the diesel engine, resulting in a decrease in power output. Fuel consumption increases, so how to deal with the particles on the trap in time is the key to DPF technology.

DPF controls and maintains a certain pressure difference before and after DPF by repeatedly regenerating PM (particulate matter). There are two methods of regeneration: active regeneration and passive regeneration: active regeneration refers to the use of external energy to increase the temperature in the trap to make the particles ignite and burn . When the temperature in the filter reaches 600°C, the deposited particles will oxidize and burn. If the temperature does not reach 600°C, too much sediment will block the filter. At this time, it is necessary to use an external energy source (such as an electric heater) , changes in burner or engine operating conditions) to increase the temperature inside the DPF to oxidize and burn particulate matter.

Passive regeneration refers to a regeneration technology in which NO2 inside the DPF reacts with C to eliminate carbon particles at a certain temperature. NO ₂ has a strong oxidative ability to the trapped particles, and the NO ₂ produced by DOC is used as an oxidant to remove the particles in the DPF and generate CO ₂ , while the NO ₂ is reduced to NO, so as to achieve the purpose of removing particles.

The traditional DPF regeneration method needs to inject a certain amount of fuel into the exhaust tailpipe, and burn the particulate matter by raising the temperature of the DOC to 600°C. This method requires a complex device and control system, and additional fuel injection is required. Will increase engine fuel consumption.

Moreover, regeneration can only burn off the carbon particles inside the DPF, but the ash trapped inside the DPF cannot be burned, which will cause the ash to accumulate in the DPF. Although the accumulation speed of ash is very slow, it will eventually lead to an increase in the pressure difference between the front and rear of the DPF, which will affect the working life of the DPF. Manually clean the DPF. The general ash cleaning method is to disassemble the DPF and clean the ash inside the DPF by high-pressure gas blowback or water washing, which is very inconvenient.

Therefore, how to improve the regeneration mode of the DPF and eliminate the dependence of the DPF on the active regeneration of fuel injection and manual dust removal is a technical problem to be solved by those skilled in the art.

Contents of the invention

The first object of the present invention is to provide a particulate trap regeneration device. The device can ensure that the particle load inside the DPF is always in a low state, and it can meet the requirements of the post-treatment system without using the DPF active regeneration system and manual dust removal.

A second object of the present invention is to provide a diesel engine provided with the particulate matter trap regeneration device.

In order to achieve the first purpose above, the present invention provides a regeneration device for a particulate matter trap, comprising:

particle trap;

oxidation catalytic converter;

The particle trap is vertically arranged vertically to the oxidation catalytic converter, and an airflow swirling device is arranged below the oxidation catalytic converter;

The airflow swirl device is provided with a particle collector.

Preferably, the airflow swirling device includes a housing;

The shell is circular in cross section, its upper end communicates with the passage of the oxidation catalytic converter, its lower end is closed, its side is provided with an air intake pipe along the tangential direction, and an airflow swirl area is formed inside.

Preferably, the particle collector includes a collection box for containing particles;

The airflow swirl area communicates with the collection box through the collection port on its side.

Preferably, the inner bottom surface of the collection box is lower than the plane where the bottom of the airflow swirling area is located.

Preferably, a particle filter is provided at the collection port.

Preferably, an upwardly protruding diversion cone is provided at the center of the bottom of the airflow swirling area.

Preferably, the smooth transition between the bottom and the side of the airflow swirl area is arc-shaped.

Preferably, the particle collector is connected to the airflow swirling device through a detachable structure or component.

Preferably, the airflow swirling device is integrated with the casing of the particle trap and the oxidation catalytic converter.

To achieve the above second objective, the present invention provides a diesel engine, comprising an engine body and an exhaust gas treatment system, the exhaust gas treatment system is provided with the regeneration device for the particulate matter trap described in any one of the above.

The particulate matter trap regeneration device provided by the present invention mainly includes a vertically arranged particulate matter trap and an oxidation catalytic converter, an airflow swirl device located below the oxidation catalytic converter, and a particulate matter collector arranged on the airflow swirl device, which can Using the vibration of the vehicle, for example, when the vehicle is driving on an uneven road at low speed, the exhaust gas flow rate is small, and the DPF captures the engine to produce larger particles or the small particles that accumulate inside the DPF will cause large particles due to the vibration of the vehicle and It falls off due to the action of gravity, and enters the airflow gyration device after passing through the DOC, and the airflow gyration device can form the engine exhaust into a turbulent airflow, and under the action of the exhaust gyration, the large particles falling off from the DPF are collected to the particle collector At the same time, passive regeneration of particulate matter occurs inside the DPF at all times. Through the joint action of these two regeneration methods, the particulate load inside the DPF is always kept at a low state, thereby reducing the number of active regeneration and manual cleaning of the DPF or not using active Regeneration or manual dust removal, thereby reducing the fuel consumption of the diesel engine and improving the reliability of the DPF.

In a preferred solution, the inner bottom surface of the collection box is lower than the plane where the bottom of the airflow swirling area is located. In this way, it can be ensured that the falling soot particles enter the collection box under the action of the rotating centrifugal force, and at the same time, the particles enter the collection box and will not enter the exhaust gas again.

In another preferred solution, an upwardly protruding diversion cone is provided at the center of the bottom of the airflow swirling area. On the one hand, the diversion cone can form an annular airflow channel through its conical surface and the bottom and side of the airflow swirling area, so as to facilitate the exhaust to form a swirling and disturbed airflow; The peripheral distribution of the airflow, so that the particles can enter the particle collector more easily.

The diesel engine provided by the present invention is equipped with the particulate matter trap regeneration device. Since the particulate matter trap regeneration device has the above technical effects, the diesel engine equipped with the particulate matter trap regeneration device also has corresponding technical effects.

Description of drawings

Fig. 1 is a structural schematic diagram of a specific embodiment of the particulate matter trap regeneration device provided by the present invention;

Fig. 2 is the top view of Fig. 1;

Fig. 3 is the A-A view of Fig. 1;

Fig. 4 is the B-B view of Fig. 3;

Fig. 5 is a perspective view of the airflow swirling device shown in Fig. 1;

Fig. 6 is a schematic diagram of the working principle of the particulate matter trap regeneration device shown in Fig. 1;

Fig. 7 is a schematic structural view of another particle collector.

In the picture:

1. Intake pipe 2. Airflow swirl device 2-1. Airflow swirl area 2-2. Guide cone 3. Particle collector 3-1 Collection box 3-2 Particle filter 4.DOC5.DPF6. Outlet pipe

detailed description

In order to enable those skilled in the art to better understand the solution of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Please refer to Fig. 1 to Fig. 5, Fig. 1 is a schematic structural diagram of a specific embodiment of the regeneration device of the particulate matter trap provided by the present invention; Fig. 2 is a top view of Fig. 1; Fig. 3 is a view of A-A of Fig. 1; Fig. 4 It is a B-B view of FIG. 3; FIG. 5 is a perspective view of the airflow swirling device shown in FIG. 1.

In a specific embodiment, the regeneration device of diesel particulate matter trap provided by the present invention is mainly composed of intake pipe 1, airflow swirl device 2, particle matter collector 3, DOC4, DPF5 and air outlet pipe 6, wherein DPF5 can adopt wall Flow honeycomb ceramic filter.

The airflow swirling device 2 is integrated with the housings of DOC4 and DPF5, and is cylindrical as a whole. The three are arranged vertically and vertically. DPF5 is located in the upper part, DOC4 is located in the middle, and the airflow swirl device 2 is located at the bottom, and a particle collector 3 is provided. .

The shell of the airflow swirling device 2 is circular in cross section, its upper end communicates with the passage of DOC4, its lower end is closed, and the side is provided with an air inlet pipe 1 along the tangential direction, forming an airflow swirling area 2-1 inside, and the airflow is under pressure. Enter the casing along the tangential direction through the inlet pipe 1, and make a rotary motion in the casing. The particles in the airflow are located at the periphery of the rotary flow due to the large centrifugal force, and finally enter the particle collector 3, and the outlet pipe 6 is located along the tangential direction. Exhaust end of DPF5.

The smooth transition between the bottom and the side of the airflow swirl area 2-1 is in the shape of a circular arc, and an upwardly protruding diversion cone 2-2 is provided at the center. On the one hand, the diversion cone 2-2 can form an annular airflow channel through its conical surface and the bottom and side of the airflow swirling area 2-1, thereby facilitating the exhaust to form a turbulent airflow; The particles are evenly distributed to the periphery of the swirling airflow, so that the particles can enter the particle collector 3 more easily.

The particle collector 3 adopts a collection box 3-1 capable of holding particles, and the airflow swirl area communicates with the collection box through a collection port on its side, and a particle filter screen 3-2 is provided at the collection port.

The inner bottom surface of the collection box 3-1 is lower than the plane where the bottom of the airflow swirling area 2-1 is located. In this way, it can be ensured that the falling soot particles enter the collection box 3-1 under the action of the rotating centrifugal force, and at the same time, the particles enter the collection box 3-1 and will not enter the exhaust gas again.

In addition, the collection box 3-1 is connected with the airflow swirling device 2 through detachable structures or components. After the soot particles are collected to a certain extent, the collection box 3-1 can be easily disassembled for cleaning.

Of course, it is also possible to clean up the collection box 3-1 by opening a discharge port without disassembling and cleaning.

Please refer to FIG. 6 , which is a schematic diagram of the working principle of the regeneration device for the particulate matter trap shown in FIG. 1 .

As shown in the figure, the exhaust gas from the engine enters the filter device of the diesel engine through the intake pipe 1, first enters the airflow swirl device 2, then forms a swirling and disturbed airflow, and then enters the DOC4. The DOC4 carrier is coated with a precious metal catalyst, which can NO in the exhaust gas is oxidized to NO ₂ ; the exhaust gas enters the DPF5 after passing through the DOC4. The DPF5 carrier is a ceramic carrier with one end open and the other end closed. Play the effect of trapping particulate matter.

As more and more particulate matter is trapped inside the DPF5, it is necessary to eliminate the carbon load accumulated inside the DPF5 in real time. The diesel engine filter system and device designed in the present invention can realize two regeneration modes:

1. DPF5 passive regeneration: carbon particles are eliminated through the chemical reaction of NO ₂ and C inside DPF5, and this regeneration reacts inside DPF5 in real time.

2. When the car is running, the DPF5 vibrates due to the excitation of the engine and the road surface, and the particles trapped in the DPF5 will fall out of the trap due to the vibration, and fall from the channel of DOC4 to the airflow swirl device 2 under the action of gravity At this time, the exhaust gas drives the falling particles to rotate at a high speed in the airflow gyratory device, and the particles enter the particle collector 3 under the action of centrifugal force.

The above two regeneration methods occur at the same time, and the combined effect ensures that the particle load inside the DPF5 is always in a low state, which can meet the regeneration requirements of the after-treatment system without using the DPF active regeneration system.

It should be noted that, in order to ensure that the present invention can realize the second regeneration mode, the above-mentioned devices must be fixed and installed vertically, and the layout design of DOC4 and DPF5 should meet the layout requirements of the whole vehicle, so as to ensure that the system can improve as much as possible without being damaged by vibration. Vibration intensity of the system to improve particle collection efficiency.

This device can shake down the ash inside the DPF5 through vibration, and collect it into the particle collector 3 under the action of the air flow, without the need for active regeneration of the DPF fuel injection, there is no problem with the above-mentioned fuel injection regeneration, and there is no need to regularly clean the ash. It avoids the inconvenience caused by regular dust cleaning, and greatly facilitates the use of users.

Certainly, the above-mentioned embodiments are only preferred solutions of the present invention, and are not limited thereto. On this basis, targeted adjustments can be made according to actual needs, so as to obtain different implementation modes. As shown in Figure 7, the collection box 3-1 can be divided into a horizontal part and a vertical part, the collection port is located at the left end of the horizontal part, and the vertical part is connected with it at the right end of the horizontal part, so that the collection port and the particle deposit part are staggered by a certain amount. In this way, the collected particles can be more effectively prevented from re-entering the exhaust gas; or, the position of the particle collector 3 on the side of the airflow swirling device can be adjusted according to the installation requirements, and so on. Since there are many ways of possible realization, it is not necessary to give examples one by one here.

In addition to the above particulate matter trap regeneration device, the present invention also provides a diesel engine, including an engine body and an exhaust gas treatment system. The exhaust gas treatment system is provided with the above-mentioned particle trap regeneration device. For other structures, please refer The prior art will not be described in detail herein.

The particulate matter trap regeneration device and the diesel engine provided by the present invention have been introduced in detail above. In this paper, specific examples are used to illustrate the principles and implementation modes of the present invention, and the descriptions of the above embodiments are only used to help understand the core idea of the present invention. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, some improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims (8)

1. A particle trap regeneration device, comprising: particle trap; oxidation catalytic converter; It is characterized in that the particle trap is vertically arranged vertically to the oxidation catalytic converter, and an airflow swirling device (2) is provided below the oxidation catalytic converter; A particle collector (3) is provided on the airflow swirling device (2); The airflow swirling device (2) includes a housing; The housing is circular in cross section, its upper end communicates with the passage of the oxidation catalytic converter, its lower end is closed, its side is provided with an air intake pipe (1) along the tangential direction, and an airflow swirl area (2-1) is formed inside ; An upwardly protruding diversion cone (2-2) is provided at the center of the bottom of the airflow swirling area (2-1). 2. The particle trap regeneration device according to claim 1, characterized in that, the particle collector (3) comprises a collection box (3-1) for containing the particles; The airflow swirl area (2-1) communicates with the collection box (3-1) through a collection port on its side. 3. The device for regenerating a particle trap according to claim 2, characterized in that, the inner bottom surface of the collection box (3-1) is lower than the plane where the bottom of the airflow swirling area (2-1) is located. 4. The device for regenerating a particle trap according to claim 3, characterized in that a particle filter (3-2) is provided at the collecting port. 5. The device for regenerating a particulate matter trap according to any one of claims 1 to 4, characterized in that, the smooth transition between the bottom and the side of the airflow swirling area (2-1) is arc-shaped. 6. The device for regenerating a particle trap according to any one of claims 1 to 4, characterized in that, the particle collector (3) is connected to the airflow swirling device (2) through a detachable structure or component. 7. The device for regenerating a particle trap according to claim 6, characterized in that the airflow swirling device (2) is integrally structured with the casing of the particle trap and the oxidation catalytic converter. 8. A diesel engine, comprising an engine body and an exhaust gas treatment system, characterized in that the exhaust gas treatment system is provided with the particulate filter regeneration device according to any one of claims 1 to 7.