Exhaust gas recirculation system, engine assembly, and vehicle

Abstract

A vehicle (3) is provided with an engine assembly (2). The engine assembly (2) includes an exhaust gas recirculation system (1). The exhaust gas recirculation system (1) includes an air inlet pipe (100), an air inlet control valve (200), an exhaust gas return pipe (300), and an exhaust pipe (400). In the longitudinal direction of the air inlet pipe (100), an air return port (130) is disposed between the air inlet (110) and the air supply port (120). The air inlet control valve (200) is disposed between the air inlet (110) and the air return port (130). The exhaust gas return pipe (400) is separately connected to the exhaust pipe (300) and the air return port (130). In the longitudinal direction of the air inlet pipe (100), the distance between the air return port (130) and the air inlet control valve (200) is S, the inner diameter of the air inlet pipe (100) is D, and S and D satisfy S / D≦2.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This disclosure claims priority to Chinese Patent Application No. 202210445423.9, entitled "EXHAUST GAS RECIRCULATION SYSTEM, ENGINE ASSEMBLY, AND VEHICLE," filed on April 26, 2022, by BYD Co., Ltd.

[0002] The present disclosure relates to the technical field of vehicles, and more particularly to exhaust gas recirculation (EGR) systems, engine assemblies, and vehicles. [Background technology]

[0003] Exhaust gas recirculation (EGR) systems typically increase the EGR rate by increasing the pressure differential between the exhaust gas return and the air return.

[0004] In the related art, an air inlet control valve is installed between the air inlet and the air return port. The throttling effect generated by the air inlet control valve creates a negative pressure in the air return port, thereby increasing the EGR rate. However, due to an improper position of the air inlet control valve, a relatively large pumping loss is generated, resulting in a relatively low EGR rate. Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure aims to solve at least one of the technical problems of the related art. Accordingly, the present disclosure aims to provide an exhaust gas recirculation (EGR) system, which has advantages such as a high EGR rate for an engine, low pumping losses, and low oil consumption.

[0006] The present disclosure further provides an engine assembly having the above-described EGR system.

[0007] The present disclosure further provides a vehicle having the above engine assembly. [Means for solving the problem]

[0008] An embodiment of a first aspect of the present disclosure provides an EGR system. The EGR system includes an air inlet pipe, an air inlet control valve, an exhaust gas return pipe, and an exhaust pipe. The air inlet pipe has an air inlet, an air supply port, and an air return port. The air inlet is configured to communicate with air. The air supply port is configured to communicate with an air inlet manifold of an engine. The air return port is located between the air inlet and the air supply port along the length of the air inlet pipe. The air inlet control valve is disposed in the air inlet pipe. The air inlet control valve is located between the air inlet and the air return port. The exhaust gas return pipe is connected to the air return port. An exhaust pipe is connected to the exhaust gas return pipe. The exhaust pipe is configured to communicate with the exhaust manifold of the engine. A distance S exists between the air return port and the air inlet control valve along the length of the air inlet pipe. The air inlet pipe has an inner diameter D. S and D satisfy S / D≦2.

[0009] The EGR system of the disclosed embodiments has advantages such as a high EGR rate for the engine, low pumping losses, and low oil consumption.

[0010] According to some embodiments of the present disclosure, the EGR system further includes a compressor. The compressor has a first end and a second end. The first end is disposed in the exhaust pipe. The first end is disposed between the engine and the exhaust gas return pipe. The second end is disposed in the air inlet pipe. The second end is disposed between the air return port and the air supply port. A distance L exists between the air return port and the second end along the length of the air inlet pipe. L and D satisfy 2≦L / D≦20.

[0011] According to some embodiments of the present disclosure, the EGR system further includes a compressor. The compressor has a first end and a second end. The first end is disposed in the exhaust pipe. The first end is placed between the engine and the exhaust gas return pipe. The second end is disposed in the air inlet pipe. The second end is placed between the air return port and the air supply port. In the longitudinal direction of the air inlet pipe, there is a distance L between the air return port and the second end. L and S satisfy S < L.

[0012] According to some embodiments of the present disclosure, the EGR system further includes a catalyst. The catalyst is disposed in the exhaust pipe. The catalyst is placed between the exhaust gas return pipe and the first end.

[0013] According to some embodiments of the present disclosure, the catalyst is a three-way catalyst.

[0014] According to some embodiments of the present disclosure, in the direction from the air return port towards the exhaust pipe, the exhaust gas return pipe gradually inclines towards the air inlet control valve.

[0015] According to some embodiments of the present disclosure, the included angle between the air inlet pipe and the exhaust gas return pipe is 10° to 90°.

[0016] According to some embodiments of the present disclosure, the EGR system further includes an air return control valve and an EGR cooler. The air return control valve is disposed in the exhaust gas return pipe. The air return control valve is configured to control the gas flow rate of the exhaust gas return pipe. The EGR cooler is disposed in the exhaust gas return pipe. The EGR cooler is placed between the air return control valve and the exhaust pipe. The EGR cooler is configured to cool the gas in the exhaust gas return pipe.

[0017] According to some embodiments of the present disclosure, an air filter is disposed in the air inlet pipe. The air filter is placed between the air inlet and the air inlet control valve.

[0018] A second embodiment of the present disclosure provides an engine assembly including the EGR system of the first embodiment and an engine having an air inlet manifold and an exhaust manifold, the air inlet manifold communicating with an air inlet pipe of the EGR system, and the exhaust manifold communicating with an exhaust pipe of the EGR system.

[0019] According to some embodiments of the present disclosure, the engine assembly further includes an intercooler disposed in the air inlet pipe adjacent to the air inlet manifold of the engine.

[0020] According to some embodiments of the present disclosure, the number of air inlet manifolds is the same as the number of cylinders in the engine.

[0021] According to some embodiments of the present disclosure, the number of exhaust manifolds is the same as the number of cylinders in the engine.

[0022] An embodiment of a third aspect of the present disclosure provides a vehicle, the vehicle including the engine assembly of the embodiment of the second aspect above.

[0023] Additional aspects and advantages of the disclosure will be set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by practice of the disclosure.

[0024] The above and / or additional aspects and advantages of the present disclosure will become apparent and understandable from the following description of the embodiments, which proceeds with reference to the drawings. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a schematic structural diagram of an exhaust gas recirculation (EGR) system according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic diagram of a theoretical flow section of an air inlet pipe of an EGR system according to an embodiment of the present disclosure. [Figure 3] FIG. 2 is a schematic diagram of a hot exhaust gas region of an air inlet pipe of an EGR system according to an embodiment of the present disclosure. [Figure 4] 1 is a schematic diagram of an engine assembly arrangement according to an embodiment of the present disclosure. FIG. [Figure 5] 1 is a schematic structural diagram of an engine assembly according to an embodiment of the present disclosure; FIG. [Figure 6] 1 is a schematic diagram of a vehicle according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0026] DETAILED DESCRIPTION OF THE INVENTION Hereinafter, embodiments of the present disclosure will be described in detail, and the embodiments described with reference to the drawings are exemplary.

[0027] In describing the present disclosure, it should be understood that orientations or positional relationships indicated by terms such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" are based on the orientations or positional relationships shown in the drawings and are used merely for ease and brevity of describing the present disclosure, and do not indicate or imply that the described devices or elements are required to have a particular orientation or be configured and operated in a particular orientation. Thus, these terms should not be construed as limitations on the present disclosure.

[0028] In describing this disclosure, the terms "first feature" and "second feature" can explicitly or implicitly include one or more features.

[0029] In the context of this disclosure, "plurality" means two or more.

[0030] An exhaust gas recirculation (EGR) system 1 according to an embodiment of the present disclosure will now be described with reference to the drawings.

[0031] As shown in FIGS. 1 to 4, an EGR system 1 according to an embodiment of the present disclosure includes an air inlet pipe 100, an air inlet control valve 200, an exhaust gas return pipe 300, and an exhaust pipe 400.

[0032] The air inlet pipe 100 has an air inlet 110, an air supply port 120, and an air return port 130. The air inlet 110 is configured to be in communication with air. The air supply port 120 is configured to be in communication with an air inlet manifold 910 of the engine 900. The air return port 130 is located between the air inlet 110 and the air supply port 120 in the longitudinal direction of the air inlet pipe 100. An air inlet control valve 200 is disposed in the air inlet pipe 100. The air inlet control valve 200 is located between the air inlet 110 and the air return port 130. An exhaust gas return pipe 300 is in communication with the air return port 130. An exhaust pipe 400 is in communication with the exhaust gas return pipe 300. The exhaust pipe 400 is configured to be in communication with an exhaust manifold 920 of the engine 900. In the longitudinal direction of the air inlet pipe 100, there is a distance S between the air return port 130 and the air inlet control valve 200. The air inlet pipe 100 has an inner diameter D. S / D≦2.

[0033] For example, an air filter 210 is disposed in the air inlet pipe 100. The air filter 210 is located between the air inlet 110 and the air inlet control valve 200.

[0034] It should be noted that “S” may be the minimum distance between the center point of the air return port 130 and the air inlet control valve 200 along the length of the air inlet pipe 100 .

[0035] According to the EGR system 1 of the embodiment of the present disclosure, the air inlet pipe 100 is provided with an air inlet 110, an air supply port 120, and an air return port 130, the air inlet 110 is configured to communicate with air, and the air supply port 120 is configured to communicate with an air inlet manifold 910 of the engine 900. In this way, fresh air can enter the air inlet pipe 100 through the air inlet 110 of the air inlet pipe 100 and be distributed to each cylinder of the engine 900 through the air supply port 120 and the air inlet manifold 910 of the engine 900, so that the engine 900 can operate normally.

[0036] In addition, in the longitudinal direction of the air inlet pipe 100, the air return port 130 is located between the air inlet 110 and the air supply port 120, the exhaust pipe 400 is configured to communicate with an exhaust manifold 920 of the engine 900, and the exhaust gas return pipe 300 communicates with the exhaust pipe 400 and the air return port 130. In this way, the exhaust gas generated by the engine 900 can enter the exhaust gas return pipe 300 through the exhaust pipe 400 and then enter the air inlet pipe 100 through the air return port 130, so that the incompletely combusted air in the exhaust gas can re-enter the engine 900 through the air inlet pipe 100, thereby realizing the circulation and reuse of exhaust gas.

[0037] Furthermore, the air inlet control valve 200 is disposed in the air inlet pipe 100, and the air inlet control valve 200 is located between the air inlet 110 and the air return port 130. In this way, after the exhaust gas enters the air inlet pipe 100 through the air return port 130, the exhaust gas can flow directly toward the engine 900; that is, the air inlet control valve 200 does not prevent the exhaust gas from circulating into the engine 900, and therefore the exhaust gas and fresh air can mix in the air inlet pipe 100 and enter the engine 900. This achieves a more rational structural arrangement.

[0038] In addition, there is a distance S between the air return port 130 and the air inlet control valve 200 in the longitudinal direction of the air inlet pipe 100. The air inlet pipe 100 has an inner diameter D, where S / D≦2. The theoretical flow area on the side of the air inlet control valve 200 facing the air supply port 120 is defined as area C below. As shown in FIG. 3 , due to the throttling effect of the air inlet control valve 200, the flow portion of the theoretical area of ​​the pipe on the side of the air inlet control valve 200 facing the air supply port 120 is reduced. The reduction in the flow portion of the theoretical area increases the air flow velocity in the theoretical flow area. Since the air flow velocity in the above-mentioned region C is higher than the air flow velocity in the region of the air inlet pipe 100 between the air supply port 120 and the air inlet control valve 200, the dynamic pressure in region C is higher than the dynamic pressure in the region of the air inlet pipe 100 between the air supply port 120 and the air inlet control valve 200, and the static pressure in region C is lower than the static pressure in the region of the air inlet pipe 100 between the air supply port 120 and the air inlet control valve 200. Setting the distance between the air return port 130 and the air inlet control valve 200 relatively small helps to increase the pressure difference between the air return port 130 and the exhaust gas return pipe 300, thereby increasing the EGR rate and reducing pumping loss.

[0039] With reference to FIG. 3, the pressure difference in the region C and the pressure difference in the region of the air inlet pipe 100 between the air supply port 120 and the air inlet control valve 200 will be explained by way of example.

[0040] First, it is assumed that there are regions E and F in the air inlet pipe 100. Region F corresponds to the location of the air return port 130. Region E is located on the side of the air return port 130 away from the air inlet control valve 200.

[0041] The theoretical flow fraction of region E is E1. The theoretical flow fraction of region F is F1. In addition, the total pressure of region F is P1 and the airflow velocity is v1. The dynamic pressure of region F is P dynamic1 , static pressure is P static1 P1=P dynamic1 +P static1 The total pressure in region E is P2 and the airflow velocity is v2. The dynamic pressure in region E is P dynamic2 , static pressure is Pstatic2 P2=P dynamic2 +P static2 is.

[0042] Since there is no throttling mechanism between zones E and F, no significant pressure loss or throttling effect occurs between zones E and F, and the total pressure in zone E is approximately equal to the total pressure in zone F, i.e., P1 = P2.

[0043] Due to the throttling effect of the air inlet control valve 200, the air flow can only move through region C toward the air supply port 120. Therefore, the theoretical flow portion of the air flow on the side facing the air supply port 120, which is closer to the mixing valve, is significantly reduced. The reduced portion F1 is significantly smaller than portion E1. Because the reduction in the portion increases the air flow velocity, the gas flow velocity in portion F1 is relatively high. The air flow velocity in portion F1 is higher than the air flow velocity in portion E1.

[0044] Dynamic pressure calculation formula P dynamic =ρv 2 According to / 2, the dynamic pressure in part F1 increases, and P dynamic2 <P dynamic1 is.

[0045] In summary, P static1 <P static2 is.

[0046] Therefore, the static pressure in region C is relatively low and the static pressure outside region C is relatively high. Setting S / D≦2 increases the pressure difference between the air inlet 110 and the exhaust gas return pipe 300, increases the amount of exhaust gas circulation, and helps reduce pumping losses, thereby achieving the maximum EGR rate with the minimum pumping losses and thereby reducing fuel consumption.

[0047] In this way, the EGR system 1 of the embodiment of the present disclosure has advantages such as a high EGR rate for the engine 900, low pumping losses, and low oil consumption.

[0048] In some specific embodiments of the present disclosure, as shown in FIGS. 2 and 4, the EGR system 1 further includes a pressurizer 500.

[0049] The compressor 500 has a first end 510 and a second end 520. The first end 510 is disposed in the exhaust pipe 400. The first end 510 is disposed between the engine 900 and the exhaust gas return pipe 300. The second end 520 is disposed in the air inlet pipe 100. The second end 520 is disposed between the air return port 130 and the air supply port 120. Specifically, when the engine 900 is operating, the exhaust pipe 400 discharges exhaust gas. The exhaust gas can drive the first end 510 of the compressor 500 to operate. The first end 510 transmits power to the second end 520. To compress the gas in the air inlet pipe 100, the rotation direction of the second end 520 of the compressor 500 is the same as the flow direction of the gas in the air inlet pipe 100. In this way, recirculated exhaust gases and fresh air can enter engine 900 more quickly.

[0050] There is a distance L between the air return port 130 and the second end 520 in the length direction of the air inlet tube 100, where 2≦L / D≦20. For example, L / D may be 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20. It should be noted that “L” may be the distance between the center point of the air return port 130 and the second end 520 in the length direction of the air inlet tube 100. For example, “L” is the minimum distance between the center point of the air return port 130 and the second end 520 in the length direction of the air inlet tube 100.

[0051] It should be noted that during operation of the engine 900, hot recirculated exhaust gases enter the air inlet pipe 100 through the air return port 130. In the air inlet pipe 100, the hot exhaust gases are mixed with fresh air that enters the air inlet pipe through the air inlet control valve 200. In the region near the air return port 130 (e.g., region G), the hot exhaust gases are relatively hot (typically 120°C to 150°C), while the fresh air is relatively cool.

[0052] With the setting of 2 ≤ L / D, in the longitudinal direction of the air inlet pipe 100, the distance L between the air return port 130 and the second end 520 is relatively large. Therefore, the high-temperature exhaust gas and the fresh air enter the second end 520 of the pressurizer 500 after being completely mixed. In this way, the risk of surge of the pressurizer 500 is reduced, the pressurization efficiency of the pressurizer 500 is improved, and the reliable operation of the pressurizer 500 is guaranteed. Furthermore, with the setting of L / D ≤ 20, the throttling loss caused by the extremely long air flow path can be avoided, and the pump loss of the engine 900 is further reduced. In this way, a relatively high EGR rate can be realized with a relatively low pump loss, thereby realizing low oil consumption in the full load mode.

[0053] [[ID=**6**]] In some specific embodiments of the present disclosure, as shown in FIGS. 1 and 2, the EGR system 1 further includes a pressurizer 500. The pressurizer 500 has a first end 510 and a second end 520. The first end 510 is disposed in the exhaust pipe 400 and is placed between the engine 900 and the exhaust gas return pipe 300. The second end 520 is disposed in the air inlet pipe 100 and is placed between the air return port 130 and the air supply port 120. In the longitudinal direction of the air inlet pipe 100, there is a distance L between the air return port 130 and the second end 520, and S < L. Therefore, the distance S between the air return port 130 and the air inlet control valve 200 is smaller, and the distance L between the air return port 130 and the second end 520 is larger, which helps increase the pressure difference between the air inlet 110 and the exhaust gas return pipe 300, increase the exhaust gas circulation amount, and reduce the pump loss, realizing the maximum EGR rate with the minimum pump loss, thereby reducing the fuel consumption rate. In addition, the high-temperature exhaust gas and the fresh air can enter the second end 520 of the pressurizer 500 after being completely mixed. In this way, the risk of surge of the pressurizer 500 is reduced, the pressurization efficiency of the pressurizer 500 is improved, and the reliable operation of the pressurizer 500 is guaranteed.

[0054] 1 and 2, the EGR system 1 further includes a catalyst 600. The catalyst 600 is disposed in the exhaust pipe 400. The catalyst 600 is located between the exhaust gas return pipe 300 and the first end 510.

[0055] For example, the catalyst 600 may be a three-way catalyst. The arrangement of the catalyst 600 can purify the exhaust gas emitted by the engine 900. For example, the catalyst 600 can convert CO, HC, or NOx in the exhaust gas into harmless carbon dioxide, water, and nitrogen, reducing the amount of harmful gases emitted into the air, and can further purify the exhaust gas into cleaner gas before the exhaust gas enters the air inlet pipe 100, which makes it easier for the engine 900 to reuse it and reduces problems such as carbon deposition, coking, and gas flow path blockage in the engine 900.

[0056] In some specific embodiments of the present disclosure, as shown in Figures 2 to 4, in the direction from the air return port 130 toward the exhaust pipe 400, i.e., from the end of the exhaust gas return pipe 300 connected to the air return port 130 to the end of the exhaust gas return pipe 300 away from the air return port 130, the exhaust gas return pipe 300 gradually slopes toward the air inlet control valve 200.

[0057] Therefore, the included angle between the flow direction of the circulating exhaust gas in the exhaust gas return pipe 300 and the flow direction of the fresh air in the air inlet pipe 100 is relatively small, so the exhaust gas can quickly enter the air inlet pipe 100, which ensures that the exhaust gas can enter the air inlet pipe 100 more smoothly, thereby further increasing the EGR rate. Furthermore, the flow collision between the exhaust gas and the fresh air can be reduced, and the exhaust gas can be quickly mixed with the fresh air after entering the air inlet pipe 100 and flow more smoothly, which further increases the flow rate of the mixed air and helps the mixed air enter the engine 900, increases the EGR rate, reduces pumping losses, and thereby achieves low oil consumption under full load mode.

[0058] 2 to 4, the included angle W between the air inlet pipe 100 and the exhaust gas return pipe 300 is 10° to 90°. For example, the included angle between the air inlet pipe 100 and the exhaust gas return pipe 300 may be 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85°, or 90°. However, the included angle is not limited to these.

[0059] It should be noted that the included angle between the portion of the air inlet pipe 100 connected to the exhaust gas return pipe 300 and the exhaust gas return pipe 300 is 10° to 90° (end point value included).

[0060] In this way, the extremely small included angle between the air inlet pipe 100 and the exhaust gas return pipe 300 can prevent the exhaust gas flow rate in the exhaust gas return pipe 300 from becoming extremely small, which allows the exhaust gas to enter the air inlet pipe 100 quickly and ensures a smooth flow of exhaust gas. In addition, the extremely large included angle between the air inlet pipe 100 and the exhaust gas return pipe 300 can prevent the flow direction of the exhaust gas in the exhaust gas return pipe 300 from being opposite to the flow direction of the fresh air in the air inlet pipe 100, which prevents the fresh air in the air inlet pipe 100 from colliding with the exhaust gas and ensures the total flow rate of the exhaust gas and fresh air in the air inlet pipe 100. In this way, pumping losses can be reduced and a relatively high EGR rate can be ensured, thereby achieving low oil consumption in full load mode.

[0061] In some specific embodiments of the present disclosure, as shown in FIGS. 1 and 5, the EGR system 1 further includes an air return control valve 700 and an EGR cooler 800.

[0062] The air return control valve 700 is disposed in the exhaust gas return pipe 300. The air return control valve 700 is configured to control the gas flow rate in the exhaust gas return pipe 300. Specifically, the air return control valve 700 can adjust the flow rate of exhaust gas in the exhaust gas return pipe 300. The EGR cooler 800 is disposed in the exhaust gas return pipe 300. The EGR cooler 800 is disposed between the air return control valve 700 and the exhaust pipe 400. The EGR cooler 800 is configured to cool the gas in the exhaust gas return pipe 300.

[0063] For example, when the engine 900 is not running, the initial state of the air return control valve 700 is closed, and the initial state of the air inlet control valve 200 is open. During operation of the engine 900, the engine 900 discharges exhaust gas. In this case, the air return control valve 700 can be gradually opened, so that the exhaust gas returns to the engine 900 through the exhaust gas return pipe 300. When the engine 900 requires a high EGR rate, the opening of the air return control valve 700 can be increased and the air inlet control valve 200 can be appropriately closed to increase the flow rate of exhaust gas entering the air inlet pipe 100, thereby increasing the EGR rate.

[0064] In addition, the arrangement of the EGR cooler 800 allows the high-temperature exhaust gas to be cooled in the exhaust gas return pipe 300, so that the exhaust gas has a relatively low temperature when it enters the air inlet pipe 100. In this way, the mixed gas of the exhaust gas and fresh air is prevented from becoming extremely hot, which further reduces the risk of surge in the compressor 500, improves the compression efficiency of the compressor 500, and ensures reliable operation of the compressor 500. Furthermore, the exhaust gas in the exhaust gas return pipe 300 needs to be cooled by the EGR cooler 800 before passing through the air return control valve 700, so that damage to the air return control valve 700 caused by high-temperature gas can be avoided, thereby prolonging the service life of the air return control valve 700.

[0065] An engine assembly 2 according to an embodiment of the present disclosure will now be described with reference to FIGS.

[0066] 1 and 5 , the engine assembly 2 includes the EGR system 1 according to the above-described embodiment of the present disclosure and an engine 900. The engine 900 has an air inlet manifold 910 and an exhaust manifold 920. The air inlet manifold 910 is in communication with the air inlet pipe 100 of the EGR system 1. The exhaust manifold 920 is in communication with the exhaust pipe 400 of the EGR system 1.

[0067] The number of air inlet manifolds 910 may correspond one-to-one with the number of cylinders of engine 900. The number of exhaust manifolds 920 may correspond one-to-one with the number of cylinders of engine 900. Gas from air inlet pipe 100 can enter the cylinders of engine 900 through each of the multiple air inlet manifolds 910, and exhaust gases produced after combustion in the cylinders can be discharged to exhaust pipe 400 through each of the multiple air inlet manifolds 910.

[0068] The engine assembly 2 of the embodiment of the present disclosure uses the EGR system 1 of the above embodiment of the present disclosure, which has advantages such as a high EGR rate for the engine 900, low pumping losses, and low oil consumption.

[0069] 1 and 5 , engine assembly 2 further includes an intercooler 810. Intercooler 810 is disposed in air inlet pipe 100. Intercooler 810 is adjacent to air inlet manifold 910 of engine 900. In this manner, intercooler 810 may further reduce the temperature of the air and exhaust gas mixture entering engine 900 to avoid excessively high combustion temperatures of engine 900, thereby further reducing fuel consumption, reducing oil consumption, and improving durability of engine 900.

[0070] A vehicle 3 according to an embodiment of the present disclosure will be described below with reference to Figure 6. The vehicle 3 includes the engine assembly 2 according to the above embodiment of the present disclosure.

[0071] The vehicle 3 of the embodiment of the present disclosure uses the engine assembly 2 of the above embodiment of the present disclosure, which has advantages such as a high EGR rate of the engine 900, low pumping losses, and low fuel consumption.

[0072] Other configurations and operations of the EGR system 1, engine assembly 2, and vehicle 3 of the presently disclosed embodiments are known to those skilled in the art and, therefore, will not be described in detail herein.

[0073] In the description herein, a description presented with reference to terms such as "one embodiment," "some embodiments," "exemplary embodiment," "one example," "particular example," and "some examples" means that the particular feature, structure, material, or characteristic described with reference to the embodiment or example is included in at least one embodiment or example of the present disclosure. In the description herein, exemplary references to the above terms do not necessarily refer to the same embodiment or example.

[0074] While embodiments of the present disclosure have been illustrated and described, it should be understood by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the present disclosure, the scope of which is defined by the appended claims and their equivalents. [Explanation of symbols]

[0075] 1. EGR system 2 Engine Assembly 3 vehicles 100 Air inlet pipe 110 Air inlet 120 Air supply port 130 Air return port 200 Air inlet control valve 210 Air Filter 300 Exhaust gas return pipe 400 exhaust pipe 500 Pressure Regulator 510 first end 520 second end 600 catalyst 700 Air return control valve 800 EGR cooler 810 Intercooler 900 Engine 910 Air Inlet Manifold 920 exhaust manifold

Claims

1. An exhaust gas recirculation system (1), comprising: an air inlet pipe (100), the air inlet pipe (100) having an air inlet (110), an air supply port (120), and an air return port (130), the air inlet (110) configured to communicate with air, the air supply port (120) configured to communicate with an air inlet manifold (910) of an engine (900), and the air return port (130) located between the air inlet (110) and the air supply port (120) along the length of the air inlet pipe (100); an air inlet control valve (200), the air inlet control valve (200) being disposed in the air inlet pipe (100), the air inlet control valve (200) being located between the air inlet (110) and the air return port (130); an air filter (210) disposed in the air inlet pipe (100), the air filter (210) being located between the air inlet (110) and the air inlet control valve (200); an exhaust gas return pipe (300), the exhaust gas return pipe (300) communicating with the air return port (130); an exhaust pipe (400), the exhaust pipe (400) being configured to communicate with the exhaust gas return pipe (300) and the exhaust pipe (400) being configured to communicate with an exhaust manifold (920) of the engine (900); Equipped with In the longitudinal direction of the air inlet pipe (100), a distance S between the air return port (130) and the air inlet control valve (200) and an inner diameter D of the air inlet pipe (100) are configured to satisfy S / D≦2; The present invention further includes a pressurizer (500), the pressurizer (500) having a first end (510) and a second end (520), and the inner diameter D and the distance L between the air return port (130) and the second end (520) in the length direction of the air inlet pipe (100) are configured to satisfy 2≦L / D≦20; The exhaust gas recirculation system (1) has a catalyst (600) disposed on the exhaust pipe (400), which converts CO, HC, or NOx in the exhaust gas into carbon dioxide, water, or nitrogen.

2. An exhaust gas recirculation system (1) as described in claim 1, wherein the first end (510) of the pressurizer (500) is arranged in the exhaust pipe (400), the first end (510) is placed between the engine and the exhaust gas return pipe (300), the second end (520) is arranged in the air inlet pipe (100), and the second end (520) is placed between the air return port (130) and the air supply port (120).

3. The first end (510) of the pressurizer (500) is arranged in the exhaust pipe (400), the first end (510) is placed between the engine and the exhaust gas return pipe (300), the second end (520) is arranged in the air inlet pipe (100), the second end (520) is placed between the air return port (130) and the air supply port (120), 2. The exhaust gas recirculation system (1) of claim 1, wherein a distance L exists between the air return port (130) and the second end (520) in the length direction of the air inlet pipe (100), and L and S satisfy S<L.

4. An exhaust gas recirculation system (1) as described in claim 3, wherein the catalyst (600) is arranged in the exhaust pipe (400), and the catalyst (600) is placed between the exhaust gas return pipe (300) and the first end (510).

5. The exhaust gas recirculation system (1) of claim 4, wherein the catalyst (600) is a three-way catalyst.

6. 6. The exhaust gas recirculation system (1) according to claim 1, wherein the exhaust gas return pipe (300) is gradually inclined towards the air inlet control valve (200) in a direction from the air return port (130) towards the exhaust pipe (400).

7. The exhaust gas recirculation system (1) according to claim 6, wherein the included angle between the air inlet pipe (100) and the exhaust gas return pipe (300) is between 10° and 90°.

8. an air return control valve (700), the air return control valve (700) being disposed in the exhaust gas return pipe (300), the air return control valve (700) being configured to control the gas flow rate in the exhaust gas return pipe (300); an exhaust gas recirculation cooler (800), the exhaust gas recirculation cooler (800) being arranged in the exhaust gas return pipe (300), the exhaust gas recirculation cooler (800) being placed between the air return control valve (700) and the exhaust pipe (300), the exhaust gas recirculation cooler (800) being configured to cool gas in the exhaust gas return pipe (300); An exhaust gas recirculation system (1) according to any one of claims 1 to 5, further comprising:

9. An engine assembly (2), comprising: The exhaust gas recirculation system (1) according to any one of claims 1 to 5, Engine (900) and Equipped with The engine (900) has an air inlet manifold (910) and an exhaust manifold (920), the air inlet manifold (910) communicating with the air inlet pipe (100) of the exhaust gas recirculation system (1), and the exhaust manifold (920) communicating with the exhaust pipe (400) of the exhaust gas recirculation system (1).

10. 10. The engine assembly (2) of claim 9, further comprising an intercooler (810), the intercooler (810) disposed in the air inlet pipe (100), the intercooler (810) adjacent the air inlet manifold (910) of the engine.

11. An engine assembly (2) as described in claim 9, wherein the number of air inlet manifolds (910) is the same as the number of cylinders of the engine (900).

12. An engine assembly (2) as described in claim 9, wherein the number of exhaust manifolds (920) is the same as the number of cylinders of the engine (900).

13. A vehicle (3) comprising the engine assembly (2) according to claim 9.

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