CN113969852A

CN113969852A - Exhaust gas recirculation system, engine intake and exhaust system and vehicle

Info

Publication number: CN113969852A
Application number: CN202010718758.4A
Authority: CN
Inventors: 赵振兴; 石伟
Original assignee: Great Wall Motor Co Ltd
Current assignee: Great Wall Motor Co Ltd
Priority date: 2020-07-23
Filing date: 2020-07-23
Publication date: 2022-01-25

Abstract

The present disclosure relates to an exhaust gas recirculation system, an engine intake and exhaust system, and a vehicle, wherein the exhaust gas recirculation system includes a circulation line (2) connecting an intake manifold (12) and an exhaust manifold (11) of the engine, and a condenser (21) and an EGR valve sequentially provided on the circulation line, and the exhaust gas recirculation system further includes H₂O₂Injection branch (3), H₂O₂The injection branch is connected into a circulation pipeline or a combustion chamber (1) of the engine. Thus, by adding H₂O₂Spray branch, H₂O₂Being a strong oxidizer, PM can be further oxidized, and PM in the engine raw exhaust can be reduced. At the same time, H₂O₂Pyrogenically produced HO₂Has effects in accelerating hydrocarbon combustion and reducing NO_XTime of generation, thereby reducing NO in the original exhaust of the engine_X. Furthermore, H₂O₂The gas is further decomposed to generateOH and O of₂Can improve the combustion efficiency and save fuel.

Description

Exhaust gas recirculation system, engine intake and exhaust system and vehicle

Technical Field

The disclosure relates to the technical field of engine emission reduction, in particular to an exhaust gas recirculation system, an engine air intake and exhaust system and a vehicle.

Background

No. in the emission regulations of gasoline engine type or diesel engine type_XEmissions have always exhibited a tendency to tighten. In-industry reduction of NO_XThe primary method of the original emission is to use EGR (Exhaust Gas Re-circulation) technology as waste GasGas recirculation) means that part of the exhaust gases from the engine is returned to the intake manifold and re-enters the cylinder together with fresh mixture. Because the waste gas contains a large amount of CO₂Equal polyatomic gas, and CO₂When the gas can not be combusted, the gas absorbs a large amount of heat due to high specific heat capacity, so that the maximum combustion temperature of the gas mixture in the cylinder is reduced, and NO is reduced_XThe amount of production of (c).

Engine emissions PM (particulate matter, primarily carbon particulates) are caused by insufficient oxygen in the combustion chamber, and according to industry experience, EGR technology does not help the engine to reduce PM, even increasing PM emissions. Also, the exhaust gas recirculation system has low combustion efficiency and the slow combustion rate results in NO being generated_XMuch, the oil consumption is increased.

Disclosure of Invention

It is a first object of the present disclosure to provide an exhaust gas recirculation system that addresses the NO present in the original emissions at the original combustion chamber exit of the engine_XAnd the technical problems of more PM and high oil consumption.

A second object of the present disclosure is to provide an engine intake and exhaust system comprising the exhaust gas recirculation system provided by the present disclosure.

A third object of the present disclosure is to provide a vehicle including an exhaust gas recirculation system or an engine intake and exhaust system provided by the present disclosure.

In order to achieve the above object, the present disclosure provides an exhaust gas recirculation system including a circulation line connecting an intake manifold and an exhaust manifold of an engine, and a condenser and an EGR valve sequentially disposed on the circulation line, the exhaust gas recirculation system further including H₂O₂Injection branch, said H₂O₂The injection branch is connected to the circulation line or to a combustion chamber of the engine.

Alternatively, the H₂O₂The spray branch comprising means for storing the liquid H₂O₂A branch pipe connecting the storage tank and the circulation pipe, and a nozzle formed at the end of the branch pipe.

Optionally, a flow meter is arranged on the branch pipeline, and the nozzle and the flow meter are respectively connected with an electronic control unit of the engine.

Alternatively, the H₂O₂An injection branch is connected into the circulation pipeline and is positioned upstream of the condenser.

Alternatively, the H₂O₂An injection branch is connected into the circulation pipeline and is positioned at the downstream of the condenser.

Optionally, H inside the storage tank₂O₂The concentration of (A) is 30-60%.

According to the second aspect of the present disclosure, there is also provided an engine intake and exhaust system, comprising an engine, an intake manifold, an exhaust manifold, a supercharging branch connecting the intake manifold and the exhaust manifold, and an exhaust gas recirculation branch, wherein the exhaust gas recirculation branch is a circulation branch in the exhaust gas recirculation system as described above.

Optionally, the boost branch is located between the engine and the exhaust gas recirculation branch.

Optionally, the exhaust gas recirculation branch is located between the engine and the supercharging branch.

According to a third aspect of the present disclosure, there is also provided a vehicle comprising an exhaust gas recirculation system as described above or an engine intake and exhaust system as described above.

By the technical scheme, H is₂O₂The injection branch is connected into the circulation line or the combustion chamber of the exhaust gas recirculation system, in order to inject H into the circulation line or the combustion chamber₂O₂Liquid particles pyrolyzed into H by high-temperature exhaust gas₂O₂Gas, H₂O₂The gas is further decomposed into two OH groups, or 1/2O₂+H₂O, or H₂O+HO₂After they enter the engine combustion chamber, PM (carbon particles) in the combustion chamber is further oxidized, so that the engine PM emission can be reduced. H₂O₂HO generated by pyrolysis of exhaust gas recirculation system₂Phase contrast O₂And H₂Has effects of accelerating combustion of hydrocarbons, shortening combustion lag time, accelerating combustion speed of hydrocarbons in combustion chamber, and reducing NO_XTime of generation, thereby reducing engine NO_XAnd (6) original ranking. H₂O₂OH and O produced by further decomposition of the gas₂Can improve the combustion efficiency of the combustion chamber and save fuel oil.

Additional features and advantages of the disclosure will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure without limiting the disclosure. In the drawings:

FIG. 1 is a first schematic diagram illustrating an exhaust gas recirculation system according to an exemplary embodiment of the present disclosure;

fig. 2 is a schematic structural diagram ii of an exhaust gas recirculation system according to an exemplary embodiment of the present disclosure.

Description of the reference numerals

1 Combustion Chamber 11 exhaust manifold

12 intake manifold 2 circulation pipeline

21 condenser 22 EGR valve

3 H₂O₂ Spray branch 31 storage tank

32 branch pipe 33 nozzle

34 flow meter 4 pressurizing branch

41 turbine 42 compressor

5 post-processor 6 intercooler

7 air filter

Detailed Description

The following detailed description of specific embodiments of the present disclosure is provided in connection with the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present disclosure, are given by way of illustration and explanation only, not limitation.

In the present disclosure, "inner and outer" refer to the inner and outer of the respective component profiles, unless otherwise stated. Furthermore, the terms "first," "second," and the like, as used in this disclosure, are intended to distinguish one element from another, and not necessarily for order or importance. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated.

Referring to fig. 1 and 2, the present disclosure provides an exhaust gas recirculation system including a circulation line 2 connecting an intake manifold 12 and an exhaust manifold 11 of an engine, and a condenser 21 and an EGR valve 22 sequentially disposed on the circulation line 2. The exhaust gas recirculation system is designed to redirect a small amount of exhaust gas to the intake manifold 12 at higher vehicle speeds, the lower the temperature of the exhaust gas, the lower the NO production from the engine_XThe better the suppression effect, the condenser 21 can reduce the temperature of the exhaust gas entering the combustion chamber 1, which is beneficial for reducing the thermal load of the engine and can reduce the temperature of the engine, the EGR valve 22 is used for independently and accurately controlling the amount of the exhaust gas recirculated to the engine, when the engine is running under load, the EGR valve 22 is opened, and part of the exhaust gas in the exhaust manifold 11 of the engine enters the intake manifold 12 and is mixed with air to enter the combustion chamber 1; at idle the EGR valve 22 is closed and exhaust gases are not recirculated to the engine and the amount of exhaust gases entering the combustion chamber 1 is proportionally adjusted according to the magnitude of the engine speed and load. In the exhaust gas recirculation system provided by the disclosure, H is additionally arranged₂O₂Injection branch 3, H₂O₂The injection branch 3 opens into the circuit 2 or into the combustion chamber 1 of the engine. Here, it should be noted that H₂O₂The injection branch 3 can be H with strong oxidizer action₂O₂Gas, also liquid H₂O₂Is prepared from H₂O₂Spraying liquid particles into the circulation line 2, H₂O₂The liquid particles are pyrolyzed into H by the high-temperature exhaust gas in the circulation line 2₂O₂Gas, to H₂O₂The liquid can be pyrolyzed completely, H₂O₂The gas is then decomposed into two OH's (hydroxyl as a strong oxidant), or H₂O₂The gas is decomposed into 1/2O₂+H₂O, or H₂O+HO₂After they enter the engine combustion chamber, PM (carbon particles) in the combustion chamber is further oxidized, and the chemical formula is: HO₂+C→CO₂+H、C+1/2O₂→CO、2HO+C→CO₂+H₂Therefore, PM in original exhaust of the engine can be reduced; in addition, H₂O₂HO generated by pyrolysis of exhaust gas recirculation system₂Phase contrast O₂And H₂Has effects of accelerating combustion of hydrocarbons, shortening combustion lag time, accelerating combustion speed of hydrocarbons in combustion chamber, and reducing NO_XTime of generation, thereby reducing NO in the original exhaust of the engine_X(ii) a In addition, by adding H₂O₂Injection branch 3, adding more OH and O to combustion chamber 1₂The combustion efficiency is improved, and the fuel-saving effect can be achieved. Of course, can be reacted with H₂O₂Other strong oxidizers that the gas performs the same function are within the scope of the present disclosure.

By the technical scheme, H is₂O₂The injection branch 3 is connected into the circulating pipeline 2 or the combustion chamber 1 of the engine, and can reduce NO in the original emission of the engine_XPM can also play the effect of saving fuel simultaneously, accords with the rule and the requirement of environmental protection design, practices thrift the energy consumption.

Specifically, referring to fig. 1, 2, H₂O₂The injection branch 3 comprises a reservoir for storing the liquid H₂O₂ A branch pipe 32 connecting the storage tank 31 and the circulation pipe 2, and a nozzle 33 formed at the end of the branch pipe. H in the storage tank 31₂O₂Flows from the branch line 32 to the nozzle 33 and is injected into the circulation line 2 or the combustion chamber 1. When assembling, the branch pipe 32 with the nozzle 33 can be inserted into the combustion chamber 1 or the circulation pipe 2, and the nozzle 33 can increase the contact area with the engine exhaust gas under a certain injection pressure, thereby performing the functions of sufficient pyrolysis and oxidation.

Further, a flow meter 34 is provided on the branch pipe 32, and the nozzle 33 and the flow meter 34 are connected to an Electronic Control Unit (ECU) of the engine, respectivelyAre connected. The flow meter 34 can meter the flow H of the storage tank 31 out of the branch pipe 32₂O₂Flow rate, the operating state of the nozzle 33 is controlled by an Electronic Control Unit (ECU), specifically, the ECU controls the opening and closing of the nozzle 33 and H according to the operating condition of the engine₂O₂The flow rate of (c).

Referring to FIGS. 1, 2, H₂O₂The injection branch 3 can branch into the circulation line 2 upstream of the condenser 21. H is more favored due to the higher exhaust gas temperature upstream of condenser 21₂O₂Pyrolysis of liquid particles.

Of course, the embodiments of the present disclosure do not limit H₂O₂The injection branch 3 opens into the circulation line 2 at a specific point, in other embodiments H₂O₂The injection branch 3 can also be connected into the circulation line 2 downstream of the condenser 21, and can also be used to introduce the liquid H₂O₂And (4) completely decomposing.

According to some embodiments, the storage tank 31 is filled with a gas₂O₂May be 30% to 60%. For example, when the concentration is 60% H₂O₂When the injection amount is 10% of the fuel injection amount, PM can be reduced by about 15%, oil can be saved by 0.1-0.4 kg/hundred kilometers, and NO of the engine can be reduced_XThe original row is about 8 percent.

In another aspect of the present disclosure, an engine intake and exhaust system is also provided, which includes an engine, an intake manifold 12, an exhaust manifold 11, a supercharging branch 4 connecting the intake manifold 12 and the exhaust manifold 11, and an exhaust gas recirculation branch, which is the circulation branch 2 in the exhaust gas recirculation system described above. The supercharging branch 4 may be a turbocharger located between an intake side and an exhaust side of the engine, the turbocharger includes a turbine 41 disposed on the exhaust manifold 11 and a compressor 42 disposed on the intake manifold 12, high-temperature exhaust gas in the exhaust manifold 11 pushes the turbine 41 to rotate at a high speed, and drives an impeller of the compressor 42 coaxially disposed on the intake manifold 12 to rotate, so as to press external air into the intake manifold 12, and thus, air before entering an engine cylinder is compressed by the turbocharger to increase the density of the air, so that more air is filled into the cylinder, and thus, the engine power is increased. The advantages of the engine intake and exhaust system and the exhaust gas recirculation system are the same as those of the prior art, and are not described in detail herein.

Specifically, the exhaust gas recirculation branch in the intake and exhaust system of the engine may be a high-pressure exhaust gas recirculation branch, or may be a low-pressure exhaust gas recirculation branch, and only some examples are described below with reference to the drawings.

Referring to fig. 2, the supercharging branch 4 is located between the engine and the exhaust gas recirculation branch 2, and at this time, the exhaust gas recirculation branch is a low-pressure exhaust gas recirculation branch to form a low-pressure exhaust gas recirculation system, and at this time, the pressure difference between the inlet end and the outlet end of the low-pressure exhaust gas recirculation branch is large, so that more exhaust gas can be circulated to the inlet manifold 12 through the exhaust gas recirculation system, and the low-pressure exhaust gas recirculation system is mainly applied to gasoline vehicles.

Referring to fig. 1, the exhaust gas recirculation branch is located between the engine and the supercharging branch 4, and in this case, the exhaust gas recirculation system is a high-pressure exhaust gas recirculation branch and forms a high-pressure exhaust gas recirculation system, which is mainly applied to diesel vehicles.

Referring to fig. 2, the engine intake and exhaust system further includes an after-processor 5, an intercooler 6, and an air cleaner 7, wherein the after-processor 5 is used for cleaning exhaust pollutants; the intercooler 6 is arranged between the supercharging branch 4 and the intake manifold 12 and is used for reducing the temperature of the supercharged high-temperature air so as to reduce the heat load of the engine and improve the air inflow, and further increasing the power of the engine; the air filter 7 plays a role in filtering dust and sand in air, and ensures that sufficient and clean air enters the cylinder.

According to the third aspect of the present disclosure, a vehicle is also provided, which includes the exhaust gas recirculation system and the engine intake and exhaust system provided by the present disclosure, and the vehicle has the same advantages of the exhaust gas recirculation system and the engine intake and exhaust system described above compared with the prior art, and the description thereof is omitted.

The preferred embodiments of the present disclosure are described in detail with reference to the accompanying drawings, however, the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present disclosure within the technical idea of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

It should be noted that, in the foregoing embodiments, various features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various combinations that are possible in the present disclosure are not described again.

In addition, any combination of various embodiments of the present disclosure may be made, and the same should be considered as the disclosure of the present disclosure, as long as it does not depart from the spirit of the present disclosure.

Claims

1. An exhaust gas recirculation system, including a circulation line (2) connecting an exhaust manifold (11) and an intake manifold (12) of an engine, and a condenser (21) and an EGR valve (22) which are sequentially provided on the circulation line (2), characterized in that the exhaust gas recirculation system further includes H₂O₂Injection branch (3), said H₂O₂The injection branch (3) is connected into the circulation pipeline (2) or the combustion chamber (1) of the engine.

2. The exhaust gas recirculation system of claim 1, wherein the H₂O₂The injection branch (3) comprises a device for storing liquid H₂O₂A branch pipe (32) connecting the storage tank (31) and the circulation pipe (2), and a nozzle (33) formed at an end of the branch pipe.

3. An exhaust gas recirculation system according to claim 2, characterized in that a flow meter (34) is provided on the branch conduit (32), the nozzle (33) and the flow meter (34) being connected to an electronic control unit of the engine, respectively.

4. The exhaust gas recirculation system of claim 2, wherein the reservoir is configured to store exhaust gasH in the storage tank (31)₂O₂The concentration of (A) is 30-60%.

5. The exhaust gas recirculation system of claim 1, wherein the H₂O₂An injection branch (3) opens into the circulation line (2) and is located upstream of the condenser (21).

6. The exhaust gas recirculation system of claim 1, wherein the H₂O₂The injection branch (3) is connected into the circulation pipeline (2) and is positioned at the downstream of the condenser (21).

7. An engine intake and exhaust system comprising an engine, an intake manifold (12), an exhaust manifold (11), a supercharging branch (4) connecting the intake manifold (12) and the exhaust manifold (11) and an exhaust gas recirculation branch, characterized in that the exhaust gas recirculation branch is the circulation branch (2) in the exhaust gas recirculation system according to any one of claims 1-6.

8. Engine intake and exhaust system according to claim 7, characterized in that the supercharging branch (4) is located between the engine and the exhaust gas recirculation branch.

9. The engine intake and exhaust system according to claim 7, characterized in that the exhaust gas recirculation branch is located between the engine and the supercharging branch (4).

10. A vehicle comprising an exhaust gas recirculation system according to any one of claims 1 to 6 or an engine inlet and exhaust system according to any one of claims 7 to 9.