Engine EGR exhaust gas and air mixing structure, engine and vehicle

Abstract

The present invention relates to the field of vehicle engine technology, and discloses an engine EGR exhaust gas and air mixing structure, an engine, and a vehicle. The engine EGR exhaust gas and air mixing structure is connected to a supercharger and includes an air intake pipe and an exhaust gas intake pipe. The air intake pipe is fixedly connected to the supercharger and communicates with the exhaust gas intake pipe. The supercharger is provided with a supercharger compressor, and the air intake pipe corresponds to the impeller of the supercharger compressor. A vortex generator and a condensate return trough are provided on the inner wall of the air intake pipe from the connection between the air intake pipe and the exhaust gas intake pipe to the supercharger. The vortex generator is provided on the inner wall of the air intake pipe, and the condensate return trough connects the vortex generator and the exhaust gas intake pipe. The present invention ensures uniform mixing of fresh air and exhaust gas while also discharging condensate, thereby preventing condensate from entering the supercharger compressor and damaging the supercharger.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle engines, and in particular to an engine EGR exhaust gas and air mixing structure, an engine and a vehicle. Background Art

[0002] Exhaust Gas Recirculation (EGR) is an effective measure to reduce NOx emissions within engine cylinders. Its operating principle is to cool a portion of the engine's exhaust gas, then return it to the engine cylinders through the intake system to participate in the combustion process. EGR is categorized by exhaust gas intake location as either low-pressure EGR or high-pressure EGR: high-pressure EGR takes air before the catalyst, while low-pressure EGR takes air after the catalyst. The gases in the low-pressure EGR combustion chamber are composed of two components: fresh air introduced by the air filter and exhaust gas taken from the catalyst and cooled by the EGR cooler. These two gases are mixed before the turbocharger compressor and then enter the combustion chamber through the turbocharger, intercooler, and intake manifold to participate in combustion. The low-pressure EGR mixing structure of gasoline turbocharged engines ensures a thorough mixing of exhaust gas and fresh air, meeting the turbocharger's operating requirements. If the uniformity of the mixed gas does not meet the requirements, it will cause abnormal noise in the turbocharger and reduce the efficiency of the compressor, thereby affecting the engine performance; in addition, if the EGR high-temperature water vapor mixes with the air and condenses to form water droplets, it will enter the turbocharger and damage the turbocharger compressor blades.

[0003] In the prior art, patent publication number CN106837617A discloses a high-uniformity EGR mixing device, which can guide EGR gas into an intake elbow and fully and evenly mix the EGR gas with air. For example, the patent with publication number CN114542335A discloses a low-pressure EGR mixing structure of a gasoline supercharged engine, including an exhaust gas intake pipe and a fresh air intake pipe connected thereto; the exhaust gas intake pipe is composed of a cylindrical intake section and an expansion mixing section connected thereto, the diameter of the cylindrical intake section of the exhaust gas intake pipe is D1, and the diameter of the fresh air intake pipe is D2; the expansion mixing section is composed of a crescent-shaped surface, a bottom surface and two prisms with the same structure; the bottom surface of the expansion mixing section is connected to the other end of the cylindrical intake section; the crescent-shaped surface of the expansion mixing section and the upper sides of the two prisms are connected to the fresh air intake pipe to form an exhaust gas injection outlet of the exhaust gas intake pipe on the fresh air intake pipe, and the injected exhaust gas is mixed with the fresh air; the other end of the fresh air intake pipe is a mixed gas outlet, which is connected to the supercharger and corresponds to the center of the supercharger compressor impeller; it can improve the uniformity of mixing of fresh air and exhaust gas, and meet the supercharger's requirements for intake gas uniformity.

[0004] Although the above-mentioned prior arts all improve the mixing uniformity of fresh air and exhaust gas by improving the EGR mixing structure, none of them considers the risk of condensed water forming after the high-temperature exhaust gas of the supercharged engine mixes with the air and enters the supercharger compressor to damage the supercharger. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide an engine EGR exhaust gas and air mixing structure, an engine and a vehicle, which can not only ensure the uniformity of mixing of fresh air and exhaust gas, but also discharge condensed water to avoid the problem of condensed water entering the supercharger compressor and damaging the supercharger.

[0006] The present invention solves the above technical problems through the following technical means:

[0007] In the first aspect, the present invention discloses an engine EGR exhaust gas and air mixing structure, which is connected to a supercharger and includes an air intake pipe and an exhaust gas intake pipe. The air intake pipe is fixedly connected to the supercharger, and the air intake pipe is connected to the exhaust gas intake pipe. A supercharger compressor is provided in the supercharger, and the air intake pipe corresponds to the impeller of the supercharger compressor. A vortex generator and a condensate return tank are provided on the inner wall of the air intake pipe from the connection between the air intake pipe and the exhaust gas intake pipe to the supercharger. The vortex generator is provided on the inner wall of the air intake pipe, and the condensate return tank connects the vortex generator and the exhaust gas intake pipe. This technical solution is to set a vortex generator and a condensate return tank on the inner wall of the air intake pipe, and fresh air and EGR exhaust gas are introduced from the air intake pipe and the exhaust gas intake pipe respectively. The exhaust gas introduced through the exhaust gas intake pipe generates a vortex through the vortex generator, and the exhaust gas vortex is fully mixed with the fresh air introduced through the air intake pipe to improve the uniformity of the mixing of air and exhaust gas. The mixed gas enters the combustion chamber through the engine intake system to participate in combustion, thereby ensuring the performance of the engine; and the condensed water separated in this solution flows back to the exhaust gas intake pipe along the condensate return tank under the action of gravity, and flows back to the exhaust system under the action of gravity for discharge, thereby preventing the condensed water from damaging the compressor impeller.

[0008] Furthermore, the diameter of the air intake pipe is D1, the diameter of the exhaust gas intake pipe is D2, and D1>D2; the distance from the intersection of the center line of the exhaust gas intake pipe and the inner wall of the air intake pipe to the center of the impeller of the supercharger compressor is L1, and L1>2*D1.

[0009] Furthermore, the vortex generator includes a generator bottom surface, a generator top surface and a crescent-shaped generator curved surface, the generator bottom surface is fixedly connected to the inner wall of the air intake pipe, and the generator curved surface faces back to the supercharger; the inclination angle of the center of the vortex generator along the height direction is β, where 0°<β<80°, and the height of the vortex generator is L2, where 0.1*D1<L2<0.9*D1.

[0010] Through the above scheme, the exhaust gas is ejected through the exhaust gas intake pipe, and after hitting the mixing generator, it is separated into two air flows under the blocking effect of the mixing generator. The two air flows will generate a vortex on the vortex generator, and then form a "kidney"-shaped vortex. The "kidney"-shaped vortex of the exhaust gas is fully mixed with the fresh air introduced through the air intake pipe, which can further improve the uniformity of the mixing of air and exhaust gas.

[0011] Furthermore, the condensate return groove is a groove structure provided on the air intake pipe, and the lowest point of the condensate return groove is the connection between the condensate return groove and the exhaust gas intake pipe. This arrangement of the technical solution makes it easier for condensate to flow out.

[0012] Furthermore, the included angle between the center line of the air intake pipe and the center line of the exhaust gas intake pipe is α, wherein 0°<α<90°.

[0013] Furthermore, the distance from the leading edge of the connection position between the vortex generator and the air intake pipe to the trailing edge of the connection position between the air intake pipe and the exhaust gas intake pipe is L3, wherein 0<L3<3*D1.

[0014] Furthermore, the distance from the leading edge of the vortex generator to the connection position between the condensate return tank and the exhaust gas intake pipe is L4, wherein L3<L4<D2*cosα.

[0015] Through the above technical solution, the mixing uniformity of exhaust gas and fresh air can be further improved.

[0016] Furthermore, the width of the top of the condensate return tank is L5, wherein 0.1*D1<L5<D1. The arrangement of this technical solution can make it easier for the condensate to flow out.

[0017] In a second aspect, the present invention further discloses an engine, which includes an engine body and the above-mentioned EGR exhaust gas and air mixing structure.

[0018] In a third aspect, the present invention further discloses a vehicle, comprising a vehicle body and the above-mentioned EGR exhaust gas and air mixing structure.

[0019] The engine EGR exhaust gas and air mixing structure, engine, and vehicle of the present invention have the following advantages:

[0020] 1. In the present invention, fresh air and EGR exhaust gas are introduced through the air intake pipe and the exhaust gas intake pipe respectively. The exhaust gas introduced through the exhaust gas intake pipe generates a "kidney"-shaped vortex through a vortex generator. The exhaust gas "kidney"-shaped vortex is fully mixed with the fresh air introduced through the air intake pipe, thereby improving the mixing uniformity of air and exhaust gas. The mixed gas enters the combustion chamber through the engine intake system to participate in combustion, thereby ensuring the performance of the engine.

[0021] 2. During the mixing process of fresh air and EGR exhaust gas in the present invention, the high-temperature water vapor in the EGR exhaust gas is cooled to form condensed water. The condensed water is separated from the mixed gas under the action of gravity and centrifugal force. The separated condensed water flows back to the exhaust gas inlet pipe along the condensate return tank under the action of gravity, and flows back to the exhaust system under the action of gravity for discharge, so as to prevent the condensed water from damaging the compressor impeller. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of an engine EGR exhaust gas and air mixing structure connected to a supercharger in use according to the present invention;

[0023] Figure 2 This is a schematic cross-sectional view of an engine EGR exhaust gas and air mixing structure according to the present invention;

[0024] Figure 3 for Figure 2 Schematic diagram of the top view structure;

[0025] Figure 4 for Figure 2 Axonometric drawing of

[0026] Figure 5 for Figure 2 Schematic diagram of the structure of the vortex generator;

[0027] Figure 6 for Figure 2 Axonometric view of the vortex generator.

[0028] Among them, the numbers in the figure represent: air intake pipe 1, exhaust gas intake pipe 2, mixing vortex generator 3, supercharger 4, vortex generator 31, condensate return tank 32, generator bottom surface 312, generator top surface 313, generator curved surface 311, supercharger compressor 41. DETAILED DESCRIPTION

[0029] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments:

[0030] The following describes the embodiments of the present invention through specific embodiments. Those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in this specification. It should be noted that the illustrations provided in the following embodiments are for illustrative purposes only and are only schematic diagrams, not actual drawings. They should not be understood as limiting the present invention. In order to better illustrate the embodiments of the present invention, some parts in the figures may be omitted, enlarged or reduced, and do not represent the dimensions of the actual product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the figures.

[0031] The same or similar numbers in the figures of the embodiments of the present invention correspond to the same or similar parts. In the description of the present invention, it should be understood that if the terms "up", "down", "left", "right", "front", "back", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the figure. This is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the figures are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0032] Example 1

[0033] like Figures 1-6 As shown, this embodiment is an engine EGR exhaust gas and air mixing structure connected to a supercharger 4 and includes an air intake pipe 1 and an exhaust gas intake pipe 2. The air intake pipe 1 has a diameter of D1, and the exhaust gas intake pipe 2 has a diameter of D2, where D1>D2. The air intake pipe 1 is fixedly connected to the supercharger 4. The air intake pipe 1 and the exhaust gas intake pipe 2 are connected. This connection can be detachable or non-detachable. The detachable connection can be a threaded connection. In this embodiment, a fixed connection is achieved by welding. The angle between the centerline of the air intake pipe 1 and the centerline of the exhaust gas intake pipe 2 is α, where 0°<α<90°, and preferably 45° in this embodiment. A supercharger compressor 41 is provided within the supercharger 4. The air intake pipe 1 corresponds to the impeller of the supercharger compressor 41, that is, the centerline of the air intake pipe 1 and the center of the impeller of the supercharger compressor 41 are aligned.

[0034] A mixing vortex generator 3 is provided on the inner wall of the air intake duct 1, extending from the junction of the air intake duct 1 and the exhaust intake duct 2 to the supercharger 4. The mixing vortex generator 3 includes a vortex generator 31 and a condensate return groove 32. The vortex generator 31 is provided on the inner wall of the air intake duct 1, while the condensate return groove 32 connects the vortex generator 31 with the exhaust intake duct 2. The vortex generator 31 includes a generator bottom surface 312, a generator top surface 313, and a crescent-shaped generator curved surface 311. The generator bottom surface 312 is fixedly connected to the inner wall of the air intake duct 1, and the generator curved surface 311 faces away from the supercharger 4. The center of the vortex generator 31 has an inclination angle β along the height direction, where 0° < β < 80°, and preferably 40° in this embodiment. The height of the vortex generator 31 is L2, where 0.1*D1 < L2 < 0.9*D1, and preferably L2 = 0.5*D1 in this embodiment.

[0035] The distance from the intersection of the centerline of the exhaust gas intake pipe 2 and the inner wall of the air intake pipe 1 to the center of the impeller of the supercharger compressor 41 is L1, where L1>2*D1. In this embodiment, L1=3*D1 is preferred. The condensate return groove 32 is a groove structure provided on the air intake pipe 1. The lowest point of the condensate return groove 32 is the physical location where it connects to the exhaust gas intake pipe 2. The distance from the leading edge of the vortex generator 31 at the connection point with the air intake pipe 1 to the trailing edge of the connection point between the air intake pipe 1 and the exhaust gas intake pipe 2 is L3, where 0<L3<3*D1. In this embodiment, L3=1.5*D1 is preferred. The distance from the leading edge of the vortex generator 31 to the connection point where the condensate return groove 32 connects to the exhaust gas intake pipe 2 is L4, where L3<L4<D2*cosα. The top width of the condensate return groove 32 is L5, wherein 0.1*D1<L5<D1. In this embodiment, L5=0.5*D1 is preferred.

[0036] In this embodiment, the engine EGR exhaust gas and air mixing structure introduces fresh air and EGR exhaust gas through the air intake pipe 1 and exhaust gas intake pipe 2, respectively. The exhaust gas introduced through the exhaust gas intake pipe 2 generates a "kidney-shaped" vortex through the vortex generator 31. The exhaust gas "kidney-shaped" vortex is fully mixed with the fresh air introduced through the air intake pipe 1, improving the uniformity of the air and exhaust gas mixing. The mixed gas enters the combustion chamber through the engine intake system to participate in combustion, ensuring engine performance. During the mixing process of fresh air and EGR exhaust gas, the high-temperature water vapor in the EGR exhaust gas cools to form condensed water. The condensed water is separated from the mixed gas under the action of gravity and centrifugal force. The separated condensed water flows back to the exhaust gas intake pipe 2 along the condensate return tank 32 under the action of gravity. It then flows back to the exhaust system under the action of gravity for removal, preventing the condensed water from damaging the compressor impeller.

[0037] Example 2

[0038] This embodiment is an engine, which includes an engine body and the EGR exhaust gas and air mixing structure of the above-mentioned embodiment 1.

[0039] Example 3

[0040] This embodiment is a vehicle, which includes a vehicle body and the EGR exhaust gas and air mixing structure of the above-mentioned embodiment 1. The vehicle of this embodiment can be a vehicle of different models.

[0041] The above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art will appreciate that the technical solutions of the present invention may be modified or replaced with equivalents without departing from the spirit and scope of the technical solutions of the present invention, and such modifications or equivalents shall be encompassed by the claims of the present invention. Any techniques, shapes, and structures not described in detail herein are well known.

Claims

1. An engine EGR exhaust gas and air mixing structure connected to a supercharger, comprising an air intake pipe and an exhaust gas intake pipe, wherein the air intake pipe is fixedly connected to the supercharger, the air intake pipe is connected to the exhaust gas intake pipe, the supercharger is provided with a supercharger compressor, and the air intake pipe corresponds to the impeller of the supercharger compressor, characterized in that: A vortex generator and a condensate return trough are provided on the inner wall of the air intake pipe from the connection between the air intake pipe and the exhaust gas intake pipe to the supercharger. The vortex generator is provided on the inner wall of the air intake pipe, and the condensate return trough connects the vortex generator and the exhaust gas intake pipe; the vortex generator includes a generator bottom surface, a generator top surface and a crescent-shaped generator curved surface, the generator bottom surface is fixedly connected to the inner wall of the air intake pipe, and the generator curved surface faces away from the supercharger; the lowest point of the physical position of the condensate return trough is the connection between the condensate return trough and the exhaust gas intake pipe.

2. The engine EGR exhaust gas and air mixing structure according to claim 1, characterized in that: The diameter of the air intake pipe is D1, the diameter of the exhaust gas intake pipe is D2, and D1>D2; the distance from the intersection of the center line of the exhaust gas intake pipe and the inner wall of the air intake pipe to the center of the impeller of the supercharger compressor is L1, and L1>2*D1.

3. The engine EGR exhaust gas and air mixing structure according to claim 2, characterized in that: The inclination angle of the center of the vortex generator along the height direction is β, wherein 0°<β<80°, and the height of the vortex generator is L2, wherein 0.1*D1<L2<0.9*D1.

4. The engine EGR exhaust gas and air mixing structure according to claim 1, characterized in that: The condensed water return groove is a groove structure arranged on the air intake pipe.

5. The engine EGR exhaust gas and air mixing structure according to claim 1, characterized in that: The included angle between the center line of the air intake pipe and the center line of the exhaust gas intake pipe is α, wherein 0°<α<90°.

6. The engine EGR exhaust gas and air mixing structure according to claim 2, characterized in that: The distance from the leading edge of the connection position between the vortex generator and the air intake pipe to the trailing edge of the connection position between the air intake pipe and the exhaust gas intake pipe is L3, wherein 0<L3<3*D1.

7. The engine EGR exhaust gas and air mixing structure according to claim 5, characterized in that: The distance from the leading edge of the vortex generator to the connection position between the condensate return tank and the exhaust gas intake pipe is L4, wherein L3<L4<D2*cosα.

8. The engine EGR exhaust gas and air mixing structure according to claim 2, characterized in that: The top width of the condensate return tank is L5, wherein 0.1*D1<L5<D1.

9. An engine, characterized in that: The engine includes an engine body and the EGR exhaust gas and air mixing structure described in any one of claims 1-8.

10. A vehicle, characterized in that: The vehicle comprises a vehicle body and the EGR exhaust gas and air mixing structure according to any one of claims 1-8.

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