CN214330776U

CN214330776U - Low-pressure EGR system of engine and engine

Info

Publication number: CN214330776U
Application number: CN202120572207.1U
Authority: CN
Inventors: 赵振兴
Original assignee: Great Wall Motor Co Ltd
Current assignee: Great Wall Motor Co Ltd
Priority date: 2021-03-19
Filing date: 2021-03-19
Publication date: 2021-10-01
Anticipated expiration: 2031-03-19

Abstract

The low-pressure EGR system comprises an exhaust gas flow path, an air flow path and an EGR flow path communicated with the exhaust gas flow path and the air flow path, wherein the EGR flow path is provided with an EGR condenser, and comprises an EGR air inlet flow path communicated with an inlet of the EGR condenser and the exhaust gas flow path and an EGR exhaust flow path communicated with an outlet of the EGR condenser and the air flow path; the low-pressure EGR system comprises an inner oven, the inner oven is arranged below an air flow path, an inner cavity is formed in the inner oven, an EGR air inlet flow path penetrates through the inner cavity of the inner oven and is separated from the inner cavity through the pipe wall of the EGR air inlet flow path so as to provide a heat source in the inner cavity, and an EGR exhaust flow path comprises a first connecting pipe and a second connecting pipe, wherein the first connecting pipe is communicated with the inner cavity and an EGR condenser outlet, and the second connecting pipe is arranged on the upper portion of the inner oven and is communicated with the inner cavity and the air flow path. The problem that moisture in the waste gas gets into freezing in the air intake system to damage the booster under low temperature environment can be solved to this disclosure.

Description

Low-pressure EGR system of engine and engine

Technical Field

The disclosure relates to the technical field of EGR (Exhaust Gas recirculation), in particular to a low-pressure EGR system of an engine and the engine.

Background

Diesel and gasoline vehicles in the industry today are equipped with EGR systems and crankcase ventilation systems. Taking a light diesel vehicle as an example, since 2020, with the implementation of the national six-emission regulationsBasically, the study of mounting "low-pressure EGR" has been started. EGR is the recirculation of a portion of exhaust gases from the engine back into the intake manifold, where the exhaust gases are mixed with fresh air and then re-introduced into the combustion chamber, due to the large amount of CO in the exhaust gases₂Equal polyatomic gas, and CO₂When the gas is not combusted, the gas absorbs a large amount of heat due to its high specific heat capacity, so that the maximum combustion temperature of the air-fuel mixture in the cylinder is lowered, thereby suppressing NO_xAnd (4) discharging.

In the related art, the "exhaust gas" from the engine contains a large amount of H₂O, H in the exhaust gas when the hot and humid exhaust gas enters the intake system to be mixed with low temperature air in the intake system after the "low pressure EGR" system is turned on in cold winter (temperature lower than, for example, -19 c)₂The O can quickly form water drops, the water drops are adhered to the wall surface of the air inlet pipeline, condensed water can be formed, and ice is formed after a few minutes. When the temperature in the cabin becomes high, the ice is separated from the wall surface of the air inlet pipeline and is brought into the compressor of the supercharger by the air flowing through at high speed. Because the impeller rotating at high speed is arranged in the compressor of the supercharger, the impeller of the supercharger can be impacted and damaged when ice blocks contact the impeller. It has been found that ice cubes of the size of the soybean particles are sufficient to damage the supercharger impeller and cause supercharger failure.

SUMMERY OF THE UTILITY MODEL

The purpose of this disclosure is to provide a low pressure EGR system of engine and engine, this low pressure EGR system of engine can solve under the low temperature environment moisture in the exhaust gas gets into the air intake system and freezes to damage the problem of booster.

In order to achieve the above object, the present disclosure provides a low pressure EGR system of an engine, the low pressure EGR system including an exhaust gas flow path communicating with an exhaust port of a turbine, an air flow path communicating with an intake port of a compressor, and an EGR flow path communicating the exhaust gas flow path and the air flow path, the EGR flow path being provided with an EGR condenser, the EGR flow path including an EGR intake flow path communicating an inlet of the EGR condenser with the exhaust gas flow path and an EGR exhaust flow path communicating an outlet of the EGR condenser with the air flow path;

the low-pressure EGR system comprises an inner oven, the inner oven is arranged below the air flow path, an inner cavity is formed in the inner oven, the EGR air inlet flow path penetrates through the inner cavity of the inner oven and is separated from the inner cavity through the pipe wall of the EGR air inlet flow path so as to be used for providing a heat source in the inner cavity, and the EGR exhaust flow path comprises a first connecting pipe and a second connecting pipe, wherein the first connecting pipe is communicated with the inner cavity and the outlet of the EGR condenser, and the second connecting pipe is arranged at the upper part of the inner oven and is communicated with the inner cavity and the air flow path.

Optionally, the internal oven includes a housing, the housing forms the inner cavity therein, and the first connecting pipe is inserted into the housing and a part of the pipe body extending into the inner cavity is located above the EGR intake flow path.

Optionally, the second connecting pipe is configured as a conical pipe, a large end of the conical pipe is connected to the air flow path, and a small end of the conical pipe is communicated with the inner cavity.

Optionally, the low pressure EGR system further includes a ventilation flow path communicating a ventilation outlet of an engine crankcase with the air flow path, a first connection port of the air flow path for communicating with the ventilation flow path is located above a second connection port of the air flow path for communicating with the second connection pipe, and a diameter of the second connection port is larger than a diameter of the first connection port.

Optionally, the air flow path includes a metal pipe communicated with an inlet of the compressor, the first connection port is disposed on an upper side of the metal pipe, and the second connection port is disposed on a lower side of the metal pipe.

Optionally, the axial direction of the metal pipe is at an angle to the horizontal plane and is inclined upward toward one end of the compressor.

Optionally, the ventilation flow path is connected to the first connection port by a metal joint configured with an annular inner cavity in which a heating coil is disposed.

Optionally, the bottom end of the metal joint is provided with a bleed air pipe inserted into the first connection port and extending into the air flow path, the end of the bleed air pipe is configured with an oblique notch, and the plane of the oblique notch is perpendicular to the pipeline cross section of the air flow path.

Optionally, the low pressure EGR system further comprises an aftertreatment system communicating the exhaust gas flow path with the EGR intake air flow path, a connection point of the aftertreatment system with the EGR intake air flow path being located on an aft end cone of the aftertreatment system.

Another aspect of the present disclosure provides an engine including the low-pressure EGR system of the engine described above.

Through above-mentioned technical scheme, this low pressure EGR system of engine that openly provides promptly utilizes the high-temperature gas in the waste gas flow path to provide the heat source for interior oven to can evaporate the comdenstion water that flows back to interior oven under the effect of gravity from the second connecting pipe, thereby can prevent to freeze in the steam entering air flow path in the waste gas, also can prevent simultaneously that the comdenstion water from flowing back to icing in the interior oven. In the specific operation, part of the exhaust gas in the exhaust gas flow path flows into the EGR air inlet flow path, a heat source is provided for the exhaust gas when the exhaust gas passes through the inner cavity of the inner oven, then the exhaust gas flows into the inner cavity through the first connecting pipe after being cooled by the EGR condenser and flows into the air flow path through the second connecting pipe arranged above the inner oven to be mixed with fresh air, and condensed water formed in the process of flowing through the second connecting pipe and at the interface of the second connecting pipe and the air flow path flows back to the inner oven under the action of gravity to be evaporated so as to prevent the condensed water from being frozen after entering the air flow path. In conclusion, the low-pressure EGR system of the engine provided by the disclosure can solve the problem that moisture in exhaust gas enters the air intake system to be frozen to damage the supercharger under a low-temperature environment.

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 schematic assembly view of a low pressure EGR system of an engine provided in an exemplary embodiment of the present disclosure;

FIG. 2 is a schematic illustration of another angle of assembly of the low pressure EGR system of the engine of FIG. 1;

FIG. 3 is a schematic illustration of the structure of the low pressure EGR system of the engine of FIG. 1 with the inner oven portion housing removed;

FIG. 4 is a perspective view of a low pressure EGR system of the engine of FIG. 1;

FIG. 5 is another angled perspective view of the low pressure EGR system of the engine of FIG. 4.

Description of the reference numerals

1, an air compressor; 2-air flow path; 21-a first connection port; 22-a second connection port; 23-a metal tube; 3-an EGR flow path; 31-EGR intake flow path; 32-EGR exhaust gas flow path; 321-a first connecting pipe; 322-a second connecting tube; 4-an EGR condenser; 5-inner oven; 51-lumen; 52-a housing; 6-a ventilation flow path; 7-a metal joint; 71-a bleed air duct; 72-oblique cuts; 8-post-treatment system.

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, unless otherwise specified, the use of directional terms such as "up" and "down" generally refers to the up and down of the space in which the engine is located when the engine is in use. "inner and outer" refer to the inner and outer of the profile of the associated member. "first, second, etc. means that there is no ordering or importance in order to distinguish one element from another.

The present disclosure will be further described with reference to the accompanying drawings and detailed description.

According to a first aspect of the present disclosure, there is provided a low pressure EGR system of an engine, as shown in fig. 1 to 5, the low pressure EGR system including an exhaust gas flow path communicating with an exhaust port of a turbine, an air flow path 2 communicating with an intake port of a compressor 1, and an EGR flow path 3 communicating the exhaust gas flow path and the air flow path 2, an EGR condenser 4 being provided on the EGR flow path 3, the EGR flow path 3 including an EGR intake flow path 31 communicating an inlet of the EGR condenser 4 with the exhaust gas flow path, and an EGR exhaust flow path 32 communicating an outlet of the EGR condenser 4 with the air flow path 2; the low-pressure EGR system comprises an inner oven 5, wherein the inner oven 5 is arranged below an air flow path 2, an inner cavity 51 is formed in the inner oven 5, an EGR air inlet flow path 31 penetrates through the inner cavity of the inner oven 5 and is separated from the inner cavity 51 through a pipe wall of the EGR air inlet flow path 31 so as to be used for providing a heat source in the inner cavity 51, and an EGR exhaust flow path 32 comprises a first connecting pipe 321 which is used for communicating the inner cavity 51 and an outlet of an EGR condenser 4, and a second connecting pipe 322 which is arranged at the upper part of the inner oven 5 and is used for communicating the inner cavity 51 and the air flow path 2.

Through above-mentioned technical scheme, this low pressure EGR system of engine that openly provides promptly utilizes the high-temperature gas in the waste gas flow path to provide the heat source for interior oven 5 to can evaporate the comdenstion water that flows back to interior oven 5 under the effect of gravity from second connecting pipe 322, thereby can prevent to freeze in the steam entering air flow path 2 in the waste gas, also can prevent that the comdenstion water from flowing back to and icing in interior oven 5 simultaneously. In a specific operation, a part of the exhaust gas in the exhaust gas flow path (the exhaust gas is high-temperature exhaust gas discharged from the engine and contains a large amount of moisture) flows into the EGR gas intake flow path 31, while passing through the inner cavity 51 of the inner oven 5, the heat source is provided to the inner cavity 51 through the pipe wall of the EGR intake flow path 31, and then the exhaust gas flows into the inner cavity 51 through the first connection pipe 321 after being cooled by the EGR condenser 4, and flows into an air flow path 2 (the air flow path 2 is an air inlet pipeline of the engine, and the air in the air flow path enters the engine after being pressurized by an air compressor 1) through a second connecting pipe 322 arranged on the inner oven 5 to be mixed with fresh air, the condensed water formed during the process of flowing through the second connection pipe 322 and at the interface of the second connection pipe 322 and the air flow path 2 flows back to the inner oven 5 under the action of gravity to evaporate, so as to prevent the condensed water from freezing after entering the air flow path 2. In conclusion, the low-pressure EGR system of the engine provided by the disclosure can solve the problem that moisture in exhaust gas enters the air intake system to be frozen to damage the supercharger under a low-temperature environment.

The internal oven 5 may be constructed in any suitable manner, with the object of utilizing the heat of the exhaust gas in the EGR gas intake flow path 31 to evaporate the condensed water that enters the internal oven 5. For example, in some embodiments, as shown with reference to fig. 3-5, the inner oven 5 includes a housing 52, with an interior cavity 51 formed in the housing 52. The housing 52 may be relatively fixed to the engine by virtue of the connections with the first connection pipe 321, the EGR intake flow path 31, and the air flow path 2. Of course, it is also possible that the housing 52 may be fixed to the engine by adding additional components such as brackets, etc., and the disclosure is not limited thereto.

In some embodiments, the housing 52 may be made of metal to enhance the heat conductivity and further accelerate the evaporation of the condensed water attached to the inner wall of the housing 52. Meanwhile, because the temperature of the exhaust gas entering the EGR inlet passage 31 is high, damage to peripheral components due to the high temperature of the EGR inlet passage 31 can be reduced by providing the housing 52, and the cost required for heat insulation measures can be reduced.

In some specific embodiments, referring to fig. 3, the first connection pipe 321 is inserted into the housing 52 and a portion of the pipe extending into the internal cavity 51 is located above the EGR intake flow path 31. In this way, the condensed water that has refluxed into the internal chamber 51 can be prevented from refluxing into the EGR condenser 4 through the first connection pipe 321, enabling to increase the reliability of the low-pressure EGR system.

In some embodiments, as shown in fig. 2 and 3, the second connection pipe 322 may be configured as a tapered pipe, a large end of the tapered pipe is connected to the air flow path 2, a small end of the tapered pipe is communicated with the inner cavity 51, so as to guide the condensed water formed at the second connection pipe 322 or an interface of the second connection pipe 322 and the air flow path 2 to flow back into the inner oven 5, and the tapered pipe structure may reduce an occupied space. The large head of the second connecting pipe 322 may be connected to the air flow path 2 in any suitable manner, for example, a flange connection or a hoop connection; similarly, the small end of the second connecting pipe 322 may be connected to the housing 51 in any suitable manner, such as welding or flange connection, and the disclosure is not limited thereto.

In some embodiments, the second connection pipe 322 may extend along a vertical direction or slightly offset from the vertical direction, so as to better guide the condensed water to flow back to the inner oven 5 for evaporation.

Based on the technical scheme, when hot gas of the engine crankcase ventilation pipe reaches the interface of the air flow path 2, water drops can be formed, if the hot gas is not processed in time, the hot gas can be frozen in the air flow path 2, and the risk of damaging the impeller of the supercharger exists. Therefore, in some embodiments, referring to fig. 2 and 4, the low pressure EGR system further includes a ventilation flow path 6 that communicates a ventilation outlet of the engine crankcase with the air flow path 2, the first connection port 21 of the air flow path 2 for communication with the ventilation flow path 6 is located above the second connection port 22 of the air flow path 2 for communication with the second connection pipe 322, and the second connection port 22 has a diameter larger than that of the first connection port 21. Thus, water drops formed at the interface between the ventilation flow path 6 and the air flow path 2, i.e., the first connection port 21, fall into the second connection pipe 322 through the second connection port 22 under the action of gravity, and then enter the inner oven 5 to evaporate, so as to prevent the formed water drops from falling into the air flow path 2 and freezing to damage the supercharger.

The supercharger has two important features, one being a compressor and the other being a turbine, which is blown by hot exhaust gases, with the impeller of the compressor being caused to rotate. When the engine works normally, the turbine has high temperature of hundreds of degrees, and the material of the supercharger is metal, and the compressor is also conducted by heat. Therefore, in order to make full use of the heat on the compressor, in some embodiments, as shown in fig. 2 and 4, the air flow path 2 includes a metal pipe 23 communicating with the inlet of the compressor 1, the first connection port 21 is provided on an upper side of the metal pipe 23, and the second connection port 22 is provided on a lower side of the metal pipe 23. The metal pipe 23 is arranged to transfer heat of the compressor to the first connecting port 21 and the second connecting port 22, so that the risk of freezing of the condensed water at the first connecting port 21 and the second connecting port 22 is further reduced.

In some embodiments, the metal pipe 23 may be an air inlet pipe integrally configured with the compressor 1, or the metal pipe 23 may be additionally disposed to connect the air inlet of the compressor 1 and the air flow path 2, and the disclosure is not limited in this respect.

Considering that the water droplets formed at the first connection port 21 may partially fall on the inner wall of the metal pipe 23 on the side of the second connection port 22 close to the compressor 1 by the air in the air flow path 2, in some embodiments, the axial direction of the metal pipe 23 is angled to the horizontal plane and inclined upward toward one end of the compressor 1. Thus, the condensed water dropped on the metal pipe 23 flows into the second connection port 22 before freezing to avoid freezing on the metal pipe 23. When the metal pipe 23 is an additionally arranged pipeline to connect the inlet of the compressor 1 and the air flow path 2, the metal pipe 23 can be obliquely arranged to enable the axis of the metal pipe to form an included angle with the horizontal plane; when the metal pipe 23 is an air inlet pipe integrally constructed with the compressor 1, the central axis of the impeller of the compressor 1 may also be set to form an included angle with the horizontal plane, and at this time, the axis of the metal pipe 23 is parallel to the central axis of the impeller of the compressor 1.

In some embodiments, as shown with reference to fig. 4 and 5, the ventilation flow path 6 is connected to the first connection port 21 through a metal joint 7, the metal joint 7 being configured with an annular inner cavity in which a heating coil is disposed. In this way, the metal joint 7 and the first connection port 21 are heated by the heating coil, and the condensed water can be further prevented from freezing at the first connection port 21. Here, the metal joint 7 may be connected to the first connection port 21 by, for example, a screw connection, and the metal joint 7 may be connected to the pipe of the ventilation flow path 6 by a hoop connection, which is not particularly limited in the present disclosure.

In some embodiments, as shown with reference to fig. 5, the bottom end of the metal connector 7 has a bleed air pipe 71 inserted into the first connection port 21 and extending into the air flow path 2, the end of the bleed air pipe 71 is configured with a chamfered cut 72, and the plane of the chamfered cut 72 is perpendicular to the pipeline cross section of the air flow path 2. In this way, the bleed air duct 71 and the chamfer 72 not only increase the siphon action to "pump out" the gas in the crankcase, but also guide the condensate more precisely into the second connection opening 22. In addition, by making the plane of the chamfered notch 72 perpendicular to the cross section of the duct of the air flow path 2, it is advantageous to reduce the intake resistance while having the siphon action and the guide action described above.

In view of the high PM value in the exhaust gas, which may damage the compressor 1 after entering the air flow path 2, in some embodiments, referring to fig. 1 and 2, the low pressure EGR system further includes an aftertreatment system 8 communicating the exhaust gas flow path with an EGR intake flow path 31, and a connection point of the aftertreatment system 8 with the EGR intake flow path 31 is located on a rear end cone of the aftertreatment system 8. Wherein, aftertreatment system 8 is DPF, can effectively purify the particulate matter in the waste gas, and DPF is more ripe prior art, and it is no longer repeated here. Further, connecting the EGR intake passage 31 to the aftertreatment system 8, that is, to the rear end cone of the DPF (Diesel Particulate Filter) to take the exhaust gas, is advantageous in that the exhaust gas enters the EGR intake passage 31 more than the exhaust gas is introduced into the other positions due to the large air pressure. The EGR intake flow path 31 may be connected to the DPF in any suitable manner, for example, a flange connection or a hoop connection, and the disclosure is not limited thereto.

In some embodiments, an EGR valve is provided on the EGR flow path 3 on the EGR intake flow path 31 or the EGR exhaust flow path 32 to control the opening and closing of the EGR flow path 3 by the EGR valve.

The second aspect of the present disclosure also provides an engine including the low pressure EGR system of the engine described above, and having all the advantages thereof, and the present disclosure will not be described herein in detail.

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 the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. In order to avoid unnecessary repetition, various possible combinations will not be separately described in this disclosure.

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. A low pressure EGR system of an engine, characterized in that the low pressure EGR system comprises an exhaust gas flow path communicating with an exhaust port of a turbine, an air flow path (2) communicating with an intake port of a compressor (1), and an EGR flow path (3) communicating the exhaust gas flow path and the air flow path (2), an EGR condenser (4) is provided on the EGR flow path (3), the EGR flow path (3) comprises an EGR intake flow path (31) communicating an inlet of the EGR condenser (4) with the exhaust gas flow path, and an EGR exhaust gas flow path (32) communicating an outlet of the EGR condenser (4) with the air flow path (2);

the low-pressure EGR system comprises an inner oven (5), wherein the inner oven (5) is arranged below the air flow path (2), an inner cavity (51) is constructed in the inner oven (5), the EGR air inlet flow path (31) penetrates through the inner cavity of the inner oven (5) and is separated from the inner cavity (51) through the tube wall of the EGR air inlet flow path (31) so as to be used for providing a heat source in the inner cavity (51), and the EGR exhaust flow path (32) comprises a first connecting tube (321) which is communicated with the inner cavity (51) and the outlet of the EGR condenser (4) and a second connecting tube (322) which is arranged at the upper part of the inner oven (5) and is communicated with the inner cavity (51) and the air flow path (2).

2. The low-pressure EGR system of an engine according to claim 1, wherein the internal oven (5) includes a housing (52), the housing (52) has the internal cavity (51) formed therein, and the portion of the pipe body of the first connection pipe (321) inserted into the housing (52) and extending into the internal cavity (51) is located above the EGR intake flow path (31).

3. The low-pressure EGR system of the engine according to claim 1, wherein the second connection pipe (322) is configured as a tapered pipe having a large end connected to the air flow path (2) and a small end communicating with the internal chamber (51).

4. The low pressure EGR system of an engine according to any one of claims 1 to 3, characterized in that the low pressure EGR system further comprises a ventilation flow path (6) that communicates a ventilation outlet of an engine crankcase with the air flow path (2), the first connection port (21) of the air flow path (2) for communicating with the ventilation flow path (6) is located above the second connection port (22) of the air flow path (2) for communicating with the second connection pipe (322), and the second connection port (22) has a diameter larger than that of the first connection port (21).

5. The low-pressure EGR system of the engine according to claim 4, wherein the air flow path (2) includes a metal pipe (23) communicating with an inlet of the compressor (1), the first connection port (21) is provided on an upper side of the metal pipe (23), and the second connection port (22) is provided on a lower side of the metal pipe (23).

6. Low-pressure EGR system for an engine according to claim 5, characterized in that the axial direction of the metal tube (23) is angled to the horizontal plane and is inclined upwards towards one end of the compressor (1).

7. Low-pressure EGR system according to claim 4, characterized in that the ventilation flow path (6) is connected to the first connection port (21) by means of a metal joint (7), the metal joint (7) being configured with an annular inner cavity in which a heating coil is arranged.

8. Low-pressure EGR system according to claim 7, characterized in that the bottom end of the metal joint (7) has a bleed air pipe (71) which is inserted into the first connection opening (21) and extends into the air flow path (2), the end of the bleed air pipe (71) being configured with a chamfer (72), and the plane of the chamfer (72) being perpendicular to the line cross section of the air flow path (2).

9. The low pressure EGR system of the engine according to any one of claims 1-3, characterized in that the low pressure EGR system further comprises an aftertreatment system (8) communicating the exhaust gas flow path with the EGR intake gas flow path (31), and a connection point of the aftertreatment system (8) with the EGR intake gas flow path (31) is located on a rear end cone of the aftertreatment system (8).

10. An engine, characterized in that it comprises a low-pressure EGR system of an engine according to any of claims 1-9.