Engine assembly and vehicle

Abstract

The utility model belongs to the technical field of engine air intake, and discloses an engine assembly and a vehicle, the engine assembly comprises an air intake pipe, an exhaust pipe, an EGR pipe, a mixer and a supercharger, the first end of the air intake pipe is communicated with the supercharger, the second end of the air intake pipe is communicated with the air intake end of an engine, the mixer is arranged on the air intake pipe and used for mixing air and fuel gas, and the exhaust pipe is communicated with the exhaust pipe. The exhaust pipe communicates with the air outlet end of the engine, the first end of the EGR pipe communicates with the exhaust pipe, and the second end of the EGR pipe communicates with the air inlet end of the engine and is located on the outlet side of the mixer. The vehicle comprises a chassis and the engine assembly arranged on the chassis. According to the engine assembly, the flame propagation speed in the middle of the air cylinder is effectively ensured, the spontaneous combustion probability of mixed gas at the tail end is reduced, and the knocking tendency of an engine is reduced under the condition that the EGR rate is not increased.

Description

Technical Field

[0001] The utility model relates to the technical field of engine intake, in particular to an engine assembly and a vehicle. Background Technique

[0002] At present, the national VI heavy-duty engine adopts the technical route of equivalence ratio + EGR (Exhaust Gas Re-circulation) + three-way catalysis. Natural gas, air, and EGR are mixed externally through a mixer and then enter the cylinder, and are ignited by a spark plug and burned to do work. The common working conditions of heavy-duty engines are usually distributed in medium and high loads, and knocking is the key factor restricting the development of heavy-duty gas engines towards large horsepower and high efficiency. EGR is the main means to reduce the knocking tendency. By recycling the exhaust gas of the engine back into the cylinder, the temperature of the end mixture in the cylinder is reduced.

[0003] In the prior art, the commonly used EGR form is generally high-pressure EGR. Specifically, the exhaust gas of the engine is mixed with the air and natural gas at the intake end and then jointly introduced into the cylinder. With such a setting, the exhaust gas concentration in the middle of the cylinder is relatively high, and this part of the exhaust gas will affect the flame propagation speed after the spark plug ignites. While the exhaust gas concentration in the periphery is relatively low, which increases the probability of spontaneous combustion of the end mixture and increases the probability of the engine generating a knocking tendency. Content of the Utility Model

[0004] The purpose of the utility model is to provide an engine assembly and a vehicle, which can effectively ensure the flame propagation speed in the middle of the cylinder, reduce the probability of spontaneous combustion of the end mixture, and reduce the knocking tendency of the engine without increasing the EGR rate.

[0005] To achieve this purpose, the utility model adopts the following technical solutions:

[0006] An engine assembly includes an engine, an intake pipe, an exhaust pipe, an EGR pipe, a mixer, and a supercharger; wherein,

[0007] The first end of the intake pipe is connected to the supercharger, the second end of the intake pipe is connected to the intake end of the engine, and the mixer is arranged on the intake pipe and is used for mixing air and fuel gas;

[0008] The exhaust pipe is connected to the engine;

[0009] The first end of the EGR pipe is connected to the exhaust pipe, and the second end of the EGR pipe is connected to the intake end of the engine and is located on the outlet side of the mixer.

[0010] Preferably, the intake pipe includes an intake manifold and a plurality of intake branch pipes. The engine includes a plurality of cylinders. The mixer is disposed on the intake manifold. The first ends of the plurality of intake branch pipes communicate with the intake manifold, and the second ends of the plurality of intake branch pipes respectively communicate with the intake ports of the plurality of cylinders. The exhaust pipe communicates with the exhaust ports of the plurality of cylinders, and the second end of the EGR pipe communicates with the plurality of intake branch pipes.

[0011] Preferably, an intercooler is provided on the intake manifold, and the intercooler and the mixer are arranged in sequence along the gas flow direction in the intake manifold.

[0012] Preferably, an exhaust manifold and a plurality of exhaust branch pipes. The first ends of the plurality of exhaust branch pipes respectively communicate with the exhaust ports of the plurality of cylinders, and the second ends of the plurality of exhaust branch pipes communicate with the exhaust manifold. The first end of the EGR pipe communicates with the exhaust manifold.

[0013] Preferably, the supercharger includes a turbine and a compressor. The turbine is used to utilize the exhaust energy of the exhaust pipe to drive the compressor to pressurize the gas in the intake pipe.

[0014] Preferably, the exhaust pipe includes a first pipe portion. The first end of the first pipe portion communicates with the exhaust end of the engine, and the second end of the first pipe portion communicates with the intake end of the turbine. The first end of the EGR pipe communicates with the first pipe portion.

[0015] Preferably, an EGR cooler is provided on the EGR pipe.

[0016] Preferably, an EGR valve is provided on the EGR pipe.

[0017] Preferably, an injection valve for injecting fuel gas is provided in the supercharger.

[0018] A vehicle includes a chassis and the engine assembly according to any one of the above, and the engine assembly is disposed on the chassis.

[0019] Beneficial effects:

[0020] The engine assembly provided by the present utility model, during the operation of the air supply system, the engine discharges exhaust gas and flows through the exhaust pipe. The supercharger pressurizes the air in the intake pipe, and then the pressurized air enters the mixer and mixes with the fuel gas to form a mixture gas. The first end of the EGR pipe is connected to the exhaust pipe between the engine and the supercharger, and the second end of the EGR pipe is connected to the intake end of the engine and is located on the outlet side of the mixer. It is equivalent to that the exhaust gas in the EGR pipe enters the engine prior to the mixture gas in the mixer. Specifically, the exhaust gas that first enters the engine cylinder is distributed close to the cylinder wall under the action of tumble, and then the mixture gas formed by air and fuel gas enters. Thus, a stratified effect with a high exhaust gas concentration in the outer periphery and a low concentration in the middle can be formed in the engine. The low exhaust gas concentration in the center enables the flame propagation speed to increase after the spark plug ignites. The high exhaust gas concentration in the outer periphery also reduces the probability of the end mixture autoignition and reduces the knocking tendency of the engine. In addition, the EGR pipe is directly connected to the intake end of the engine and is located on the outlet side of the mixer, which also reduces the length of the EGR pipe and improves the responsiveness of the exhaust gas input. Description of the Drawings

[0021] Figure 1 is a schematic structural diagram of the engine assembly provided by the present utility model;

[0022] Figure 2 is a partial structural diagram of the engine cylinder provided by the present utility model.

[0023] In the figure:

[0024] 1, intake pipe; 101, intake manifold; 102, intake branch pipe; 2, exhaust pipe; 201, exhaust manifold; 202, exhaust branch pipe; 3, EGR pipe; 4, mixer; 5, injection valve; 6, supercharger; 61, turbine; 62, compressor; 7, engine; 71, cylinder; 711, cylinder block; 712, piston; 8, intercooler; 9, three-way catalytic device; 10, EGR cooler; 11, EGR valve. Detailed Description of the Embodiment

[0025] The following further describes the present utility model in detail with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present utility model, rather than limiting the present utility model. In addition, it should be noted that for the convenience of description, only some parts related to the present utility model rather than all structures are shown in the drawings.

[0026] In the description of the present utility model, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0027] In the present utility model, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over", and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "beneath", and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0028] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "right", etc. are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0029] Refer to Figures 1 to 2 As shown, this embodiment provides an engine assembly, which includes an engine 7, an intake pipe 1, an exhaust pipe 2, an EGR pipe 3, a mixer 4, and a supercharger 6. Among them, the first end of the intake pipe 1 is connected to the supercharger 6, the second end of the intake pipe 1 is connected to the intake end of the engine 7, the mixer 4 is arranged on the intake pipe 1 and is used for mixing air and fuel gas, the exhaust pipe 2 is connected to the exhaust end of the engine 7, the first end of the EGR pipe 3 is connected to the exhaust pipe 2, and the second end of the EGR pipe 3 is connected to the intake end of the engine 7 and is located on the outlet side of the mixer 4.

[0030] In this embodiment, when the air supply system is operating, the engine 7 discharges exhaust gas and flows through the exhaust pipe 2. The supercharger 6 pressurizes the air in the intake pipe 1. Subsequently, the pressurized air enters the mixer 4 and is mixed with the fuel gas to form a mixture gas. The first end of the EGR pipe 3 is connected to the exhaust pipe 2 between the engine 7 and the supercharger 6, and the second end of the EGR pipe 3 is connected to the intake end of the engine 7 and is located on the outlet side of the mixer 4. It is equivalent to that the exhaust gas in the EGR pipe 3 enters the engine 7 prior to the mixture gas in the mixer 4. Specifically, referring to Figure 2 as shown, a combustion chamber is formed between the cylinder block 711 and the piston 712 of the cylinder 71. Both the mixture gas and the exhaust gas are introduced into the combustion chamber. The exhaust gas that first enters the cylinder 71 of the engine 7 is distributed close to the cylinder wall of the cylinder block 711 of the cylinder 71 under the action of tumble. Subsequently, the mixture gas formed by air and fuel gas enters. Thus, a stratified effect with a high concentration of exhaust gas in the periphery and a low concentration in the middle can be formed in the engine 7. The low exhaust gas concentration in the center enables the flame propagation speed to increase after the spark plug ignites. The high exhaust gas concentration in the periphery also reduces the probability of spontaneous combustion of the end mixture gas and reduces the knocking tendency of the engine 7. In addition, the EGR pipe 3 is directly connected to the intake end of the engine 7 and is located on the outlet side of the mixer 4, which also reduces the length of the EGR pipe 3 and improves the responsiveness of exhaust gas input.

[0031] In this embodiment, an injection valve 5 for injecting fuel gas is provided in the supercharger 6. In this embodiment, the fuel gas ejected by the injection valve 5 can be, but is not limited to, natural gas.

[0032] Optionally, the injection valve 5 is set as an electromagnetic valve. With this setting, the response is rapid and the control is convenient.

[0033] In this embodiment, continue to refer to Figure 1 as shown, the intake pipe 1 includes an intake manifold 101 and a plurality of intake branch pipes 102. The engine 7 includes a plurality of cylinders 71. The mixer 4 is provided on the intake manifold 101. The first ends of the plurality of intake branch pipes 102 are connected to the intake manifold 101, and the second ends of the plurality of intake branch pipes 102 are respectively connected to the intake ports of the plurality of cylinders 71 in one-to-one correspondence. The exhaust pipe 2 is connected to the exhaust ports of the plurality of cylinders 71. The second end of the EGR pipe 3 is connected to the plurality of intake branch pipes 102. Specifically, the EGR pipe 3 is correspondingly connected to the intake branch pipes 102 of each cylinder 71, and can reliably and evenly feed the exhaust gas into each cylinder 71. Moreover, the distance between the second end of the EGR pipe 3 and the cylinder 71 is greatly shortened, which also improves the responsiveness of exhaust gas input.

[0034] The number of the intake branch pipes 102 is adaptively adjusted according to the number of cylinders 71 of the engine 7, and no excessive limitation is made here.

[0035] In this embodiment, an intercooler 8 is provided on the intake manifold 101, and the intercooler 8 and the mixer 4 are arranged in sequence along the gas flow direction in the intake manifold 101. Specifically, since the temperature of the exhaust gas discharged from the engine 7 is very high, the heat conduction through the supercharger 6 will increase the temperature of the intake air. Moreover, during the compression process of the air, the density will increase, and at the same time, the temperature of the air discharged from the supercharger 6 will also increase. As the air pressure increases, the oxygen density decreases, thus affecting the effective charging efficiency of the engine 7. If the charging efficiency is to be further improved, the intake air temperature needs to be reduced. By providing the intercooler 8, the compressed air can be effectively cooled. Experiments have shown that under the same air-fuel ratio condition, for every 10°C drop in the temperature of the supercharged air, the power of the engine 7 can be increased by 3% - 5%. In addition, when the uncooled supercharged air enters the combustion chamber, it will not only affect the charging efficiency of the engine 7, but also easily cause the combustion temperature of the engine 7 to be too high, resulting in faults such as knocking, and will also increase the content of NOx in the exhaust gas of the engine 7, causing air pollution. By providing the intercooler 8, air pollution can also be reduced and the generation of knocking can be suppressed.

[0036] In this embodiment, the exhaust pipe 2 includes an exhaust manifold 201 and a plurality of exhaust branch pipes 202. The first ends of the plurality of exhaust branch pipes 202 are respectively and communicatively connected to the air outlets of the plurality of cylinders 71, and the second ends of the plurality of exhaust branch pipes 202 are communicatively connected to the exhaust manifold 201. The first end of the EGR pipe 3 is communicatively connected to the exhaust manifold 201. Specifically, the exhaust gas discharged from the engine 7 flows through the air outlets of the plurality of cylinders 71 to the plurality of exhaust branch pipes 202 respectively, and then converges to the exhaust manifold 201 through the plurality of exhaust branch pipes 202. A part of the exhaust gas in the exhaust manifold 201 flows to the EGR pipe 3 and is recycled and introduced into the cylinders 71 of the engine 7.

[0037] In this embodiment, the supercharger 6 includes a turbine 61 and a compressor 62. The turbine 61 is used to utilize the exhaust energy of the exhaust pipe 2 to drive the compressor 62 to pressurize the gas in the intake pipe 1. Specifically, the exhaust gas of the engine 7 flowing through the turbine 61 can drive the turbine 61 to rotate, thereby being able to drive the compressor 62 to work and compress the air in the intake manifold 101.

[0038] Specifically, the exhaust pipe 2 includes a first pipe portion 2011. The first end of the first pipe portion 2011 is communicatively connected to the air outlet end of the engine 7, and the second end of the first pipe portion 2011 is communicatively connected to the intake end of the turbine 61. The first end of the EGR pipe 3 is communicatively connected to the first pipe portion 2011. With such a setting, the EGR pipe 3 can take gas from the exhaust gas of the engine 7 discharged from the first pipe portion 2011 and introduce this part of the gas back into the engine 7.

[0039] Specifically, the exhaust pipe 2 further includes a second pipe portion 2012. The first end of the second pipe portion 2012 communicates with the air outlet end of the turbine 61, and a three-way catalytic device 9 is provided on the second pipe portion 2012. Specifically, the first pipe portion 2011 and the second pipe portion 2012 together form the exhaust manifold 201. Specifically, the exhaust gas is discharged through the second pipe portion 2012 and will pass through the three-way catalytic device 9 during the discharging process. The three-way catalytic device 9 is the most important off-board purification device installed in the exhaust system. It can convert harmful gases such as CO, HC, and NOx discharged from vehicle exhaust into harmless carbon dioxide, water, and nitrogen through oxidation and reduction reactions. When the high-temperature vehicle exhaust passes through the three-way catalytic device 9, the purification agent in the three-way catalytic device 9 enhances the activity of the three gases of CO, HC, and NOx, prompting them to undergo a certain oxidation-reduction chemical reaction. Among them, CO is oxidized into colorless and non-toxic carbon dioxide gas at high temperature; HC compounds are oxidized into water (H2O) and carbon dioxide at high temperature; NOx is reduced into nitrogen and oxygen. The three harmful gases become harmless gases, purifying the exhaust gas.

[0040] In this embodiment, an EGR cooler 10 is provided on the EGR pipe 3. By providing the EGR cooler 10, the temperature of the exhaust gas about to be introduced into the engine 7 can be effectively reduced, thereby reducing the temperature of the combustion chamber in the subsequent cylinder 71.

[0041] In this embodiment, an EGR valve 11 is provided on the EGR pipe 3. In this embodiment, the EGR cooler 10 and the EGR valve 11 are arranged in sequence along the gas flow direction in the EGR pipe 3. Specifically, by providing the EGR valve 11, the flow rate of the exhaust gas recirculation can be flexibly controlled, that is, the amount of exhaust gas entering the combustion chamber of the cylinder 71 can be flexibly controlled.

[0042] This embodiment also provides a vehicle. It includes a chassis and the above-mentioned engine assembly, and the engine assembly is provided on the chassis. By providing the above-mentioned engine assembly on the vehicle, it can thus have all the beneficial effects of the above-mentioned engine assembly system, which will not be elaborated here too much.

[0043] Obviously, the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, various obvious changes, re-adjustments, and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims

1. An engine assembly, characterized in that: It comprises an engine (7), an intake pipe (1), an exhaust pipe (2), an EGR pipe (3), a mixer (4) and a supercharger (6); wherein: The first end of the intake pipe (1) is connected to the supercharger (6), the second end of the intake pipe (1) is connected to the intake end of the engine (7), and the mixer (4) is arranged on the intake pipe (1) and is used to mix air and fuel gas; The exhaust pipe (2) is connected to the exhaust end of the engine (7); The first end of the EGR pipe (3) is connected to the exhaust pipe (2), and the second end of the EGR pipe (3) is connected to the intake end of the engine (7) and is located at the outlet side of the mixer (4).

2. The engine assembly according to claim 1, characterized in that: The intake pipe (1) comprises an intake main pipe (101) and a plurality of intake branch pipes (102); the engine (7) comprises a plurality of cylinders (71); the mixer (4) is arranged on the intake main pipe (101); the first ends of the plurality of intake branch pipes (102) are connected to the intake main pipe (101); the second ends of the plurality of intake branch pipes (102) are connected to the intake ports of the plurality of cylinders (71) in a one-to-one correspondence; the exhaust pipe (2) is connected to the outlet ports of the plurality of cylinders (71); and the second end of the EGR pipe (3) is connected to the plurality of intake branch pipes (102).

3. The engine assembly according to claim 2, characterized in that: An intercooler (8) is provided on the intake manifold (101), and the intercooler (8) and the mixer (4) are arranged in sequence along the gas flow direction in the intake manifold (101).

4. The engine assembly according to claim 2, characterized in that: The exhaust pipe (2) comprises an exhaust main pipe (201) and a plurality of exhaust branch pipes (202); the first ends of the plurality of exhaust branch pipes (202) are connected to the exhaust ports of the plurality of cylinders (71) in a one-to-one correspondence; the second ends of the plurality of exhaust branch pipes (202) are connected to the exhaust main pipe (201); and the first end of the EGR pipe (3) is connected to the exhaust main pipe (201).

5. The engine assembly according to claim 1, characterized in that: The supercharger (6) comprises a turbine (61) and a compressor (62), wherein the turbine (61) is used to utilize exhaust energy from the exhaust pipe (2) to drive the compressor (62) to pressurize the gas in the intake pipe (1).

6. The engine assembly according to claim 5, characterized in that: The exhaust pipe (2) comprises a first pipe portion (2011), a first end of the first pipe portion (2011) being connected to an exhaust end of the engine (7), a second end of the first pipe portion (2011) being connected to an intake end of the turbine (61), and a first end of the EGR pipe (3) being connected to the first pipe portion (2011).

7. The engine assembly according to claim 1, characterized in that: An EGR cooler (10) is provided on the EGR pipe (3).

8. The engine assembly according to claim 1, characterized in that: The EGR pipe (3) is provided with an EGR valve (11).

9. The engine assembly according to claim 1, characterized in that: An injection valve (5) for injecting fuel is arranged inside the supercharger (6).

10. A vehicle, characterized in that: It comprises a chassis and an engine assembly as claimed in any one of claims 1 to 9, wherein the engine assembly is arranged on the chassis.

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