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 an exhaust gas recirculation (EGR) system, an engine assembly, and a vehicle. [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. The throttling effect generated by the air inlet control valve creates a negative pressure in the air return, thereby increasing the EGR rate. However, due to the improper position of the air inlet control valve, a relatively large pumping loss is generated, and the EGR rate is relatively low. 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. Therefore, the present disclosure aims to provide an exhaust gas recirculation (EGR) system. The EGR system has advantages such as high EGR rate of the engine, low pumping loss, 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 disposed between the air inlet and the air supply port in a length direction of the air inlet pipe. The air inlet control valve is disposed in the air inlet pipe. The air inlet control valve is disposed between the air inlet and the air return port. The exhaust gas return pipe is communicated with the air return port. The exhaust pipe is communicated with the exhaust gas return pipe. The exhaust pipe is configured to communicate with the exhaust manifold of the engine. In a length direction of the air inlet pipe, a distance S exists between the air return port and the air inlet control valve. 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 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 pressurizer. The pressurizer 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 and the air supply. A distance L exists between the air return and the second end in a length direction 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 supercharger. The supercharger 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] An embodiment of a second aspect of the present disclosure provides an engine assembly, the engine assembly including an EGR system according to the embodiment of the first aspect above, 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 an 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 which 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 can be understood from the following description of the embodiments, which proceeds with reference to the drawings. [Brief description of the drawings]

[0025] [Figure 1] FIG. 1 is a schematic structural diagram of an exhaust gas recirculation (EGR) system according to an embodiment of the present disclosure. [Diagram 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. [Diagram 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] FIG. 1 is a schematic diagram of an engine assembly arrangement according to an embodiment of the present disclosure. [Diagram 5] FIG. 1 is a schematic structural diagram of an engine assembly according to an embodiment of the present disclosure. [Figure 6] 1 is a schematic diagram of a vehicle according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] DETAILED DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a second embodiment of the present disclosure; FIG. 2 is a block diagram of a second embodiment of the present disclosure;

[0027] In describing the present disclosure, it should be understood that the 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 to facilitate and simplify the description of the present disclosure, and do not indicate or imply that the described devices or elements are required to have a particular orientation or to be configured and operated in a particular orientation. Thus, these terms should not be construed as limitations on the present disclosure.

[0028] In the description of this disclosure, a "first feature" and a "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 communicate with air. The air supply port 120 is configured to communicate with an air inlet manifold 910 of the engine 900. In the longitudinal direction of the air inlet pipe 100, the air return port 130 is disposed between the air inlet 110 and the air supply port 120. An air inlet control valve 200 is disposed in the air inlet pipe 100. The air inlet control valve 200 is disposed between the air inlet 110 and the air return port 130. An exhaust gas return pipe 300 is communicated with the air return port 130. An exhaust pipe 400 is communicated with the exhaust gas return pipe 300. The exhaust pipe 400 is configured to communicate 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 tube 100. The air filter 210 is disposed 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 130 and the air inlet control valve 200 along the length of the air inlet tube 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 disposed between the air inlet 110 and the air supply port 120, the exhaust pipe 400 is configured to communicate with the 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, thus realizing the circulation and reuse of the 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 disposed 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, in the air inlet pipe 100, the exhaust gas and fresh air can be mixed and enter the engine 900. Therefore, a more rational structural arrangement is realized.

[0038] In addition, there is a distance S between the air return port 130 and the air inlet control valve 200 in the length direction of the air inlet pipe 100. The air inlet pipe 100 has an inner diameter D. 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 of 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 that 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 the region C is higher than that 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 the region C is lower than that 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 the pumping loss.

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

[0040] It is first assumed that there are regions E and F in the air inlet pipe 100. Region F corresponds to the location of the air return 130. Region E is located on the side of the air return 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 air flow 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 air flow velocity is v2. The dynamic pressure in region E is P dynamic2 , static pressure is Pstatic2 P2=P dynamic2 +P static2 It is.

[0042] Since there is no throttling mechanism between zones E and F, no significant pressure loss or throttling effect is generated 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 the region C towards the air supply port 120. Therefore, the theoretical flow section 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 section F1 is significantly smaller than the section E1. The reduction in the section increases the air flow velocity, so the gas flow velocity in the section F1 is relatively high. The air flow velocity in the section F1 is higher than the air flow velocity in the section E1.

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

[0045] In summary, P static1 <P static2 It 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 exhaust gas circulation amount, and helps reduce the pumping loss, thereby achieving the maximum EGR rate with the minimum pumping loss, thereby reducing the specific fuel consumption.

[0047] In this manner, 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 pressurizer 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 operates, the exhaust pipe 400 discharges exhaust gas. The exhaust gas can drive the first end 510 of the pressurizer 500 to operate. The first end 510 transmits power to the second end 520. To pressurize the gas in the air inlet pipe 100, the rotation direction of the second end 520 of the pressurizer 500 is the same as the flow direction of the gas in the air inlet pipe 100. In this manner, recirculated exhaust gases and fresh air can enter engine 900 more quickly.

[0050] In the length direction of the air inlet tube 100, there is a distance L between the air return port 130 and the second end 520, and 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 130. In the air inlet pipe 100, the hot exhaust gases are mixed with fresh air which enters the air inlet pipe through the air inlet control valve 200. In the area near the air return 130 (e.g., area G), the hot exhaust gases are relatively hot (typically 120°C to 150°C), while the fresh air is relatively cold.

[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, after the high-temperature exhaust gas and the fresh air are completely mixed, they enter the second end 520 of the pressurizer 500. 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. Further, with the setting of L / D ≤ 20, the throttling loss due to the extremely long air flow path can be avoided, and the pump loss of the engine 900 can be further reduced. In this way, a relatively high EGR rate can be realized with relatively low pump loss, thereby realizing low oil consumption in the full load mode.

[0053] 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 to 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, so as to realize the maximum EGR rate with the minimum pump loss, thereby reducing the fuel consumption rate. In addition, after the high-temperature exhaust gas and the fresh air are completely mixed, they can enter the second end 520 of the pressurizer 500. 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 disposed 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 discharged 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 gas discharged into the air, and can further purify the exhaust gas into cleaner gas before the exhaust gas enters the air inlet pipe 100, which can facilitate reuse by the engine 900 and reduce 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 2-4, 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 that the exhaust gas can enter the air inlet pipe 100 quickly, which ensures that the exhaust gas can enter the air inlet pipe 100 more smoothly, thereby further increasing the EGR rate. In addition, 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, and reduces the pumping loss, thereby realizing low oil consumption in 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 thereto.

[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 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 avoid the exhaust gas flow rate in the exhaust gas return pipe 300 in the air inlet pipe 100 from being extremely small, which allows the exhaust gas to enter the air inlet pipe 100 quickly and ensures the smooth flow of the 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 exhaust gas flow direction in the exhaust gas return pipe 300 from being opposite to the fresh air flow direction 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 the fresh air in the air inlet pipe 100. In this way, the pumping loss can be reduced and a relatively high EGR rate can be guaranteed, thereby realizing 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 the 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 degree 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, due to the arrangement of the EGR cooler 800, the high-temperature exhaust gas can 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 the fresh air is prevented from becoming extremely hot, which further reduces the risk of surge in the pressurizer 500, improves the pressurizing efficiency of the pressurizer 500, and ensures the reliable operation of the pressurizer 500. In addition, 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 the damage of the air return control valve 700 caused by the 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 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 the engine 900. The number of exhaust manifolds 920 may correspond one-to-one with the number of cylinders of the engine 900. The gas in the air inlet pipe 100 can enter the cylinders of the engine 900 through the multiple air inlet manifolds 910 respectively, and the exhaust gas generated after combustion in the cylinders can be discharged to the exhaust pipe 400 through the multiple air inlet manifolds 910 respectively.

[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 high EGR rate of the engine 900, low pumping loss, and low oil consumption.

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

[0070] In the following, a vehicle 3 according to an embodiment of the present disclosure will be described with reference to Fig. 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 high EGR rate of the engine 900, low pumping loss, and low fuel consumption.

[0072] The remaining 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 provided 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 descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0074] Although 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. Vehicle 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 Pressurizer 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), the air return port (130) being 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), said air inlet control valve (200) being disposed in said air inlet pipe (100), said air inlet control valve (200) being located between said air inlet (110) and said air return (130); an exhaust gas return pipe (300), the exhaust gas return pipe (300) being in communication 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 An exhaust gas recirculation system (1), wherein a distance S exists 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, and S and D satisfy S / D≦2.

2. The engine further comprises a pressurizer (500), the pressurizer (500) having a first end (510) and a second end (520), the first end (510) being disposed in the exhaust pipe (400), the first end (510) being located between the engine and the exhaust gas return pipe (300), the second end (520) being disposed in the air inlet pipe (100), and the second end (520) being located between the air return port (130) and the air supply port (120); 2. The exhaust gas recirculation system of claim 1, wherein a distance L exists between the air return port and the second end of the air inlet pipe in the longitudinal direction thereof, and L and D satisfy 2≦L / D≦20.

3. The engine further comprises a pressurizer (500), the pressurizer (500) having a first end (510) and a second end (520), the first end (510) being disposed in the exhaust pipe (400), the first end (510) being located between the engine and the exhaust gas return pipe (300), the second end (520) being disposed in the air inlet pipe (100), and the second end (520) being located 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. 4. The exhaust gas recirculation system (1) of claim 3, further comprising a catalyst (600), the catalyst (600) being disposed in the exhaust pipe (400), the catalyst (600) being located 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. An exhaust gas recirculation system (1) according to any one of claims 1 to 5, wherein in a direction from the air return port (130) towards the exhaust pipe (400), the exhaust gas return pipe (300) is gradually inclined towards the air inlet control valve (200).

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 a gas flow rate in the exhaust gas return pipe (300); an exhaust gas recirculation cooler (800), the exhaust gas recirculation cooler (800) being disposed 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); The exhaust gas recirculation system (1) according to any one of claims 1 to 7, further comprising:

9. The exhaust gas recirculation system (1) according to any one of claims 1 to 8, wherein an air filter (210) is arranged in the air inlet pipe (100), the air filter (210) being located between the air inlet (110) and the air inlet control valve (200).

10. An engine assembly (2), The exhaust gas recirculation system (1) according to any one of claims 1 to 9, 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).

11. 11. The engine assembly (2) of claim 10, 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.

12. 11. The engine assembly (2) of claim 10, wherein the number of air inlet manifolds (910) is the same as the number of cylinders of the engine (900).

13. The engine assembly (2) of claim 10, wherein the number of exhaust manifolds (920) is the same as the number of cylinders of the engine (900).

14. A vehicle (3) comprising the engine assembly (2) according to any one of claims 10 to 13.

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