阅读说明：本技术 一种两级增压发动机egr双循环冷却系统及汽车 (Two-stage supercharged engine EGR double-circulation cooling system and automobile ) 是由 赵艳婷 胡崴 米娇 刘子豪 李平 于 2021-07-30 设计创作，主要内容包括：本申请涉及一种两级增压发动机EGR双循环冷却系统及汽车,属于汽车发动机技术领域,包括：发动机,该发动机上设有与进气歧管连接的进气管路,以及与排气歧管连接的排气管路；高压级增压器,其包括与排气管路连通的高压级涡轮机和高压级压气机；低压级增压器,其包括与高压级涡轮机连通的低压级涡轮机和低压级压气机；进气中冷器,其与高压级压气机连通；级间中冷器,其与低压级压气机和进气中冷器连通；EGR管道,该EGR管道将排气歧管与级间中冷器连通。本申请将低压级压气机排出的压缩气体和EGR管道排出的废气依次经过级间中冷器和进气中冷器进行冷却,然后再进入高压级压气机再次压缩后经进气中冷器进行二次冷却,极大地降低了发动机进气温度。(The application relates to a two-stage supercharged engine EGR dual cycle cooling system and car belongs to automobile engine technical field, includes: the engine is provided with an air inlet pipeline connected with an air inlet manifold and an exhaust pipeline connected with an exhaust manifold; a high-pressure stage supercharger comprising a high-pressure stage turbine and a high-pressure stage compressor in communication with an exhaust gas conduit; a low-pressure stage booster including a low-pressure stage turbine and a low-pressure stage compressor in communication with the high-pressure stage turbine; the air inlet intercooler is communicated with the high-pressure stage compressor; the interstage intercooler is communicated with the low-pressure stage compressor and the air inlet intercooler; an EGR conduit communicating the exhaust manifold with the interstage intercooler. Compressed gas discharged by the low-pressure-stage compressor and waste gas discharged by the EGR pipeline are sequentially cooled by the interstage intercooler and the air inlet intercooler, and then enter the high-pressure-stage compressor to be compressed again to be cooled again by the air inlet intercooler, so that the air inlet temperature of the engine is greatly reduced.)

1. A two-stage supercharged engine EGR dual cycle cooling system, comprising:

the engine (1) is provided with an air inlet pipeline (13) connected with an air inlet manifold (11) and an exhaust pipeline (14) connected with an exhaust manifold (12);

a high-pressure stage supercharger (2), the high-pressure stage supercharger (2) comprising a high-pressure stage turbine (21) communicating with the exhaust duct (14), and a high-pressure stage compressor (22) coaxially connected with the high-pressure stage turbine (21);

a low-pressure stage supercharger (3), the low-pressure stage supercharger (3) comprising a low-pressure stage turbine (31) communicating with the high-pressure stage turbine (21), and a low-pressure stage compressor (32) coaxially connected with the low-pressure stage turbine (31);

the air inlet intercooler (4), the air inlet intercooler (4) is communicated with the high-pressure stage compressor (22), and the air inlet intercooler (4) cools the compressed air of the high-pressure stage compressor (22) and then inputs the cooled compressed air into the air inlet manifold (11) through an air inlet pipeline (13);

an inter-stage intercooler (5), the inter-stage intercooler (5) being in communication with the low-pressure stage compressor (32), the inter-stage intercooler (5) cooling the compressed gas of the low-pressure stage compressor (32) and then inputting the cooled compressed gas to an intake intercooler (4), the intake intercooler (4) cooling the compressed gas of the low-pressure stage compressor (32) again and then inputting the cooled compressed gas to the high-pressure stage compressor (22);

the EGR pipeline (7) is used for communicating the exhaust manifold (12) with the interstage intercooler (5), the interstage intercooler (5) cools the exhaust gas discharged by the EGR pipeline (7) and then inputs the cooled exhaust gas into the intake intercooler (4), and the intake intercooler (4) cools the exhaust gas discharged by the EGR pipeline (7) again and then inputs the cooled exhaust gas into the high-pressure stage compressor (22).

2. A two-stage supercharged engine EGR dual cycle cooling system of claim 1 wherein:

the engine radiator is characterized by further comprising an engine radiator (6) connected with the engine (1), a water outlet of the engine radiator (6) is respectively connected with the interstage intercooler (5) and the engine 91 through a water outlet three-way pipe (61), and water outlets of the interstage intercooler (5) and the engine (1) are connected with a water inlet of the engine radiator (6) through a water return three-way pipe (62).

3. A two-stage supercharged engine EGR dual cycle cooling system of claim 1 wherein:

the air intake intercooler (4) is provided with a first cooling air passage (41) and a second cooling air passage (42) which are independent of each other, an air inlet of the first cooling air passage (41) is connected with an air outlet of the high-pressure stage compressor (22), an air outlet of the first cooling air passage (41) is connected with the air inlet pipeline (13), an air inlet of the second cooling air passage (42) is connected with an air outlet of the interstage intercooler (5), and an air outlet of the second cooling air passage (42) is connected with an air inlet of the high-pressure stage compressor (22).

4. A two-stage supercharged engine EGR dual cycle cooling system of claim 1 wherein:

the interstage intercooler (5) mixes and cools the compressed gas of the low-pressure stage compressor (32) and the exhaust gas discharged by the EGR pipeline (7), and then the mixed gas is input into the air intake intercooler (4) for cooling again.

5. A two-stage supercharged engine EGR dual cycle cooling system of claim 1 wherein:

and an EGR valve for controlling the EGR pipeline (7) to open and close is arranged on the EGR pipeline (7).

6. A two-stage supercharged engine EGR dual cycle cooling system of claim 1 wherein:

and a one-way valve for preventing gas in the EGR pipeline (7) from flowing back is arranged between the EGR pipeline (7) and the interstage intercooler (5).

7. A two-stage supercharged engine EGR dual cycle cooling system of claim 1 wherein:

the air intake intercooler (4) is an air-air cooling intercooler.

8. A two-stage supercharged engine EGR dual cycle cooling system of claim 1 wherein:

the interstage intercooler (5) is a water-air cooled intercooler.

9. A two-stage supercharged engine EGR dual cycle cooling system of claim 1 wherein:

the interstage intercooler (5) is connected with the low-pressure stage compressor (32) and the EGR pipeline (7) through an air inlet three-way pipe.

10. A motor vehicle, characterized in that it is provided with a two-stage supercharged engine EGR dual cycle cooling system according to any one of claims 1 to 9.

Technical Field

The application relates to the technical field of automobile engines, in particular to a two-stage supercharged engine EGR (exhaust gas recirculation) dual-circulation cooling system and an automobile.

Background

Exhaust Gas Recirculation (EGR) is an effective measure for reducing the generation of NOx gases in the engine cylinder, and the system mainly comprises an EGR valve, an EGR cooler, a check valve, a connecting pipeline and a controller. The working principle is as follows: a portion of the exhaust of the engine is introduced into the cylinders, reducing the in-cylinder combustion temperature and thereby reducing NOx emissions. EGR is divided into cold EGR and hot EGR, the cold EGR utilizes an EGR cooler to cool part of exhaust and then introduces the cooled exhaust into a cylinder, the hot EGR means that the exhaust directly enters the cylinder without passing through the EGR cooler, the temperature of the cold EGR is lower than that of the hot EGR, the lower in-cylinder combustion temperature can be realized, and the NOx emission is further reduced.

Along with the increasing serious environmental pollution and the increasing shortage of energy sources, the energy conservation and emission reduction of automobiles are more and more emphasized by countries in the world, and the emission regulations are increasingly strict. The main targets of the engine technical development are high efficiency, energy conservation and environmental protection, and the turbocharging technology can greatly improve the dynamic property and the economical efficiency of the engine and reduce the pollutant emission in tail gas.

A two-stage supercharging exhaust turbocharger is employed in a diesel engine for a vehicle, in which a high-pressure stage supercharger having a high-pressure turbine driven by exhaust gas discharged from an engine and a low-pressure stage supercharger having a low-pressure turbine driven by exhaust gas after driving the high-pressure stage supercharger are arranged in series in a flow path of exhaust gas, and intake air subjected to first-stage pressurization by a low-pressure compressor of the low-pressure stage supercharger is subjected to second-stage pressurization by a high-pressure compressor of the high-pressure stage supercharger and supplied to the engine.

The two-stage supercharging technology can obviously improve the power of the diesel engine, improve the low-speed torque of the diesel engine and reduce the emission and the oil consumption. Therefore, the two-stage supercharging technology becomes an important direction in the development of domestic diesel engines. The two-stage supercharging can improve the density of the mixed gas and increase the temperature of the mixed gas, and the air intake intercooler is used for cooling the intake air of the engine, namely the air after the high-pressure-stage compressor needs to be cooled, but the heat dissipation capability of the air intake intercooler is limited, so that the temperature of the air at the outlet of the low-pressure-stage compressor cannot be directly cooled to the ideal temperature at one time, and the air intake amount, the air-fuel ratio and the oil consumption of the engine are adversely affected.

Disclosure of Invention

The embodiment of the application provides a two-stage supercharged engine EGR dual cycle cooling system and an automobile to solve the problem that when the two-stage supercharged engine in the related art is high in mixed gas density, the temperature of mixed gas is increased, and adverse effects on air inflow, air-fuel ratio and oil consumption of the engine are caused.

An embodiment of the present application provides a two-stage supercharged engine EGR dual cycle cooling system of the first aspect, including:

the engine is provided with an air inlet pipeline connected with an air inlet manifold and an exhaust pipeline connected with an exhaust manifold;

the high-pressure stage supercharger comprises a high-pressure stage turbine communicated with an exhaust pipeline and a high-pressure stage compressor coaxially connected with the high-pressure stage turbine;

a low-pressure stage supercharger comprising a low-pressure stage turbine in communication with the high-pressure stage turbine, and a low-pressure stage compressor coaxially connected with the low-pressure stage turbine;

the air inlet intercooler is communicated with the high-pressure stage compressor, and cools compressed air of the high-pressure stage compressor and then inputs the cooled compressed air into an air inlet manifold through an air inlet pipeline;

the interstage intercooler is communicated with the low-pressure stage compressor, cools the compressed gas of the low-pressure stage compressor and then inputs the cooled compressed gas into the intake intercooler, and the intake intercooler cools the compressed gas of the low-pressure stage compressor again and then inputs the cooled compressed gas into the high-pressure stage compressor;

the EGR pipeline is used for communicating the exhaust manifold with the interstage intercooler, the interstage intercooler cools the exhaust gas discharged by the EGR pipeline and then inputs the cooled exhaust gas into the air intake intercooler, and the air intake intercooler cools the exhaust gas discharged by the EGR pipeline again and then inputs the cooled exhaust gas into the high-pressure stage compressor.

In some embodiments: the engine radiator is connected with the engine, a water outlet of the engine radiator is respectively connected with the interstage intercooler and the engine through a water outlet three-way pipe, and water outlets of the interstage intercooler and the engine are connected with a water inlet of the engine radiator through a water return three-way pipe.

In some embodiments: the air inlet intercooler is provided with a first cooling air passage and a second cooling air passage which are independent of each other, an air inlet of the first cooling air passage is connected with an air outlet of the high-pressure stage compressor, an air outlet of the first cooling air passage is connected with the air inlet pipeline, an air inlet of the second cooling air passage is connected with an air outlet of the inter-stage intercooler, and an air outlet of the second cooling air passage is connected with an air inlet of the high-pressure stage compressor.

In some embodiments: and the interstage intercooler mixes and cools the compressed gas of the low-pressure stage compressor and the waste gas discharged by the EGR pipeline, and then inputs the mixed gas into the air inlet intercooler for cooling again.

In some embodiments: and an EGR valve for controlling the EGR pipeline to be opened and closed is arranged on the EGR pipeline.

In some embodiments: and a one-way valve for preventing gas in the EGR pipeline from flowing backwards is arranged between the EGR pipeline and the interstage intercooler.

In some embodiments: the air intake intercooler is an air-air cooling intercooler.

In some embodiments: the interstage intercooler is a water-air cooled intercooler.

In some embodiments: the interstage intercooler is connected with the low-pressure stage compressor and the EGR pipeline through an air inlet three-way pipe.

In a second aspect, embodiments of the present application provide an automobile using a two-stage supercharged engine EGR dual cycle cooling system according to any one of the embodiments described above.

The beneficial effect that technical scheme that this application provided brought includes:

the embodiment of the application provides a two-stage supercharged engine EGR (exhaust gas recirculation) dual-cycle cooling system and an automobile, wherein the two-stage supercharged engine EGR dual-cycle cooling system is provided with an engine, and the engine is provided with an air inlet pipeline connected with an air inlet manifold and an exhaust pipeline connected with an exhaust manifold; a high-pressure stage supercharger comprising a high-pressure stage turbine in communication with the exhaust conduit and a high-pressure stage compressor coaxially connected with the high-pressure stage turbine; a low-pressure stage supercharger comprising a low-pressure stage turbine in communication with the high-pressure stage turbine, and a low-pressure stage compressor coaxially connected with the low-pressure stage turbine; the air inlet intercooler is communicated with the high-pressure stage compressor, and cools compressed air of the high-pressure stage compressor and then inputs the cooled compressed air into the air inlet manifold through an air inlet pipeline; and the interstage intercooler is communicated with the low-pressure stage compressor, cools the compressed gas of the low-pressure stage compressor and then inputs the cooled compressed gas into the air inlet intercooler, and cools the compressed gas of the low-pressure stage compressor again and then inputs the cooled compressed gas into the high-pressure stage compressor. And the EGR pipeline is used for communicating the exhaust manifold with the interstage intercooler, the interstage intercooler cools the waste gas discharged by the EGR pipeline and then inputs the cooled waste gas into the air inlet intercooler, and the air inlet intercooler cools the waste gas discharged by the EGR pipeline again and then inputs the cooled waste gas into the high-pressure stage compressor.

Therefore, the low-pressure stage supercharger of the two-stage supercharged engine EGR double-circulation cooling system compresses fresh air through the low-pressure stage compressor, compressed gas discharged by the low-pressure stage compressor and waste gas discharged by the EGR pipeline enter the interstage intercooler, the interstage intercooler cools the compressed gas of the low-pressure stage compressor and the waste gas discharged by the EGR pipeline and then inputs the cooled compressed gas and the cooled waste gas into the air inlet intercooler, and the air inlet intercooler cools the compressed gas of the low-pressure stage compressor and the waste gas discharged by the EGR pipeline again and then inputs the cooled compressed gas and the cooled waste gas into the high-pressure stage compressor. The high-pressure stage compressor compresses the compressed gas of the low-pressure stage compressor and the waste gas discharged by the EGR pipeline again, the compressed mixed gas discharged by the high-pressure stage compressor enters the air inlet intercooler, and the compressed mixed gas of the high-pressure stage compressor is cooled by the air inlet intercooler and then is input into the air inlet manifold through the air inlet pipeline to participate in combustion. According to the air-conditioning system, compressed air discharged by the low-pressure-stage compressor and waste gas discharged by the EGR pipeline are sequentially cooled through the interstage intercooler and the air inlet intercooler, and then enter the high-pressure-stage compressor for secondary cooling through the air inlet intercooler after being compressed again, so that the air inlet temperature of the engine is greatly reduced, the air input and the air mixing ratio can be greatly improved, and the oil consumption of the engine is reduced.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram provided in an embodiment of the present application.

Reference numerals:

1. an engine; 11. an intake manifold; 12. an exhaust manifold; 13. an air intake line; 14. an exhaust line;

2. a high-pressure stage supercharger; 21. a high pressure stage turbine; 22. a high-pressure stage compressor;

3. a low-pressure stage supercharger; 31. a low pressure stage turbine; 32. a low-pressure stage compressor;

4. an air intake intercooler; 41. a first cooling air duct; 42. a second cooling air duct;

5. an interstage intercooler; 6. an engine radiator; 61. a water outlet three-way pipe; 62. a water return three-way pipe; 7. an EGR conduit.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The embodiment of the application provides a two-stage supercharged engine EGR double-circulation cooling system and an automobile, which can solve the problem that the temperature of mixed gas is increased when the density of the mixed gas of a two-stage supercharged engine in the related technology is high, and adverse effects are caused on the air inflow, the air-fuel ratio and the oil consumption of the engine.

An embodiment of the present application provides a two-stage supercharged engine EGR dual cycle cooling system of the first aspect, including:

the engine 1 is provided with an air inlet pipeline 13 connected with an air inlet manifold 11, the air inlet pipeline 13 is used for providing fresh air to the inside of the engine 1 to participate in combustion in an engine cylinder, and an exhaust pipeline 14 connected with an exhaust manifold 12, and the exhaust pipeline 14 is used for exhausting exhaust gas generated by the combustion in the engine cylinder.

A high-pressure stage supercharger 2, the high-pressure stage supercharger 2 comprising a high-pressure stage turbine 21 communicating with the exhaust line 14, and a high-pressure stage compressor 22 coaxially connected to the high-pressure stage turbine 21. The exhaust gas discharged from the engine cylinder enters the high-pressure stage turbine 21 from the exhaust pipeline 14 to drive the high-pressure stage turbine 21 to rotate at a high speed, the high-pressure stage turbine 21 drives the high-pressure stage compressor 22 to rotate synchronously, and the high-pressure stage compressor 22 compresses fresh gas and then inputs the compressed gas into the air inlet pipeline 13 to provide sufficient air for the combustion of the engine 1.

A low-pressure stage supercharger 3, the low-pressure stage supercharger 3 including a low-pressure stage turbine 31 communicating with the high-pressure stage turbine 21, and a low-pressure stage compressor 32 coaxially connected to the low-pressure stage turbine 31. The exhaust gas discharged from the high-pressure stage turbine 21 enters the low-pressure stage turbine 31 to drive the low-pressure stage turbine 31 to rotate at a high speed, the low-pressure stage turbine 31 drives the low-pressure stage compressor 32 to synchronously rotate, and the low-pressure stage compressor 32 compresses fresh gas and then inputs the compressed fresh gas into the inter-stage intercooler 5 for cooling.

And the air intake intercooler 4 is communicated with the high-pressure stage compressor 22, and compressed air compressed by the high-pressure stage compressor 22 is cooled by the air intake intercooler 4 and then is input into the air intake manifold 11 through the air intake pipeline 13. The intake intercooler 4 is preferably an air-to-air cooled intercooler, and since the temperature of the compressed air pressurized by the high-pressure stage compressor 22 is inevitably increased, the intake intercooler 4 functions to reduce the temperature of the compressed air pressurized by the high-pressure stage compressor 22 to reduce the heat load of the engine 1, increase the intake air amount, and further increase the power of the engine 1.

And the interstage intercooler 5 is communicated with the low-pressure stage compressor 32, the compressed gas pressurized by the low-pressure stage compressor 32 is cooled by the interstage intercooler 5 and then is input into the air inlet intercooler 4, and the compressed gas of the low-pressure stage compressor 32 is cooled again by the air inlet intercooler 4 and then is input into the high-pressure stage compressor 22. Because the temperature of the compressed air pressurized by the low-pressure stage compressor 32 is inevitably increased, the inter-stage intercooler 5 is used for reducing the temperature of the compressed air pressurized by the low-pressure stage compressor 32, and the inter-stage intercooler 5 cools the compressed air pressurized by the low-pressure stage compressor 32 and then enters the air intake intercooler 4 for cooling again so as to reduce the heat load of the engine 1, improve the air intake amount and further increase the power of the engine 1.

And an EGR pipe 7, wherein the EGR pipe 7 communicates the exhaust manifold 12 with the intercooler 5, the intercooler 5 cools the exhaust gas discharged from the EGR pipe 7 and inputs the cooled exhaust gas into the intake intercooler 4, and the intake intercooler 4 cools the exhaust gas discharged from the EGR pipe 7 again and inputs the cooled exhaust gas into the high-pressure stage compressor 22. Because the exhaust gas discharged by the EGR pipeline 7 reaches more than 600 ℃, the interstage intercooler 5 is used for reducing the temperature of the exhaust gas discharged by the EGR pipeline 7, the exhaust gas discharged by the EGR pipeline 7 is cooled by the interstage intercooler 5 and then enters the air intake intercooler 4 for cooling again, so that the heat load of the engine 1 is reduced, the air intake amount is improved, and the power of the engine 1 is further increased.

The low-pressure stage supercharger 3 of the two-stage supercharged engine EGR double-circulation cooling system compresses fresh air through the low-pressure stage compressor 32, compressed gas discharged by the low-pressure stage compressor 32 and waste gas discharged by the EGR pipeline 7 enter the interstage intercooler 5 together, the interstage intercooler 5 cools and mixes the compressed gas of the low-pressure stage compressor 32 and the waste gas discharged by the EGR pipeline 7 and then inputs the mixture into the air intake intercooler 4, and the air intake intercooler 4 cools and mixes the compressed gas of the low-pressure stage compressor 32 and the waste gas discharged by the EGR pipeline 7 again and then inputs the mixture into the high-pressure stage compressor 22.

The high-pressure stage compressor 22 compresses the compressed gas of the low-pressure stage compressor 32 and the exhaust gas discharged from the EGR pipeline 7 again to form a compressed mixed gas, the compressed mixed gas discharged from the high-pressure stage compressor 22 enters the intake intercooler 4, and the intake intercooler 4 cools the compressed mixed gas of the high-pressure stage compressor 22 and then inputs the cooled compressed mixed gas into the intake manifold 11 through the intake pipeline 13 to participate in combustion.

Compressed gas discharged by the low-pressure stage compressor and waste gas discharged by the EGR pipeline are sequentially cooled by the interstage intercooler and the air inlet intercooler, and then enter the high-pressure stage compressor to be compressed again and then are cooled again by the air inlet intercooler. The temperature of compressed gas discharged after the low-pressure stage compressor 32 is supercharged is within 170 ℃, the temperature of the compressed gas after the low-pressure stage compressor 32 is supercharged and the temperature of exhaust gas discharged from the EGR pipeline 7 is cooled by the inter-stage intercooler 5 is within 130 ℃, and the temperature of the compressed gas after the low-pressure stage compressor 32 is supercharged and the temperature of the exhaust gas discharged from the EGR pipeline 7 is cooled by the air intake intercooler 4 is within 45 ℃. The air inlet temperature of the engine is greatly reduced, the air inlet quantity and the air mixing ratio can be greatly improved, and the oil consumption of the engine is reduced.

In some alternative embodiments: referring to fig. 1, the two-stage supercharged engine EGR dual-cycle cooling system further includes an engine radiator 6 connected to the engine 1, a water outlet of the engine radiator 6 is connected to the interstage intercooler 5 and the engine 1 through a three-way water outlet pipe 61, and water outlets of the interstage intercooler 5 and the engine 1 are connected to a water inlet of the engine radiator 6 through a three-way water return pipe 62. The inter-stage intercooler 5 is preferably a water-air cooled intercooler, and the engine coolant in the engine radiator 6 exchanges heat with the compressed gas of the low-pressure stage compressor 32 and the exhaust gas discharged from the EGR pipe 7, respectively, to lower the temperature of the compressed gas of the low-pressure stage compressor 32 and the temperature of the exhaust gas discharged from the EGR pipe 7.

In the embodiment of the application, a water outlet of an engine radiator 6 is respectively connected with the interstage intercooler 5 and the engine 1 through a water outlet three-way pipe 61, and the engine coolant in the engine radiator 6 is used for carrying out heat exchange on the compressed gas exhausted after the low-pressure stage compressor 32 in the interstage intercooler 5 is pressurized and the waste gas exhausted from the EGR pipeline 7, so that the temperature of the compressed gas exhausted after the low-pressure stage compressor 32 is pressurized and the temperature of the waste gas exhausted from the EGR pipeline 7 are reduced. The engine coolant flowing out of the inter-stage intercooler 5 and the engine coolant flowing out of the engine 1 are merged by a water return three-way pipe 62 and then flow into the engine radiator 6, and the engine radiator 6 cools and reduces the temperature of the flowing-in engine coolant for cyclic utilization.

In some alternative embodiments: referring to fig. 1, the embodiment of the application provides a two-stage supercharged engine EGR dual-cycle cooling system, and an intake intercooler 4 of the two-stage supercharged engine EGR dual-cycle cooling system is provided with a first cooling air passage 41 and a second cooling air passage 42 which are independent of each other. An air inlet of the first cooling air passage 41 is connected with an air outlet of the high-pressure stage compressor 22, and an air outlet of the first cooling air passage 41 is connected with the air inlet pipeline 13. An air inlet of the second cooling air passage 42 is connected with an air outlet of the inter-stage intercooler 5, and an air outlet of the second cooling air passage 42 is connected with an air inlet of the high-pressure stage compressor 22.

The intake intercooler 4 is provided as the first cooling air passage 41 and the second cooling air passage 42 independent of each other in the embodiment of the application, and the second cooling air passage 42 is used for circulating and cooling the compressed gas of the low-pressure stage compressor 32 cooled by the inter-stage intercooler 5 and the exhaust gas discharged from the EGR pipe 7. Compressed air pressurized by the low-pressure stage compressor 32 and cooled by the second cooling air passage 42 and exhaust gas discharged from the EGR pipeline 7 enter the high-pressure stage compressor 22 to be compressed again, compressed mixed air discharged by the high-pressure stage compressor 22 enters the first cooling air passage 41 of the intake intercooler 4, and the compressed mixed air pressurized by the high-pressure stage compressor 22 is cooled by the first cooling air passage 41 and then is input into the intake manifold 11 through the intake pipeline 13 to participate in combustion.

In some alternative embodiments: referring to fig. 1, the embodiment of the application provides a two-stage supercharged engine EGR dual-cycle cooling system, an inter-stage intercooler 5 of the two-stage supercharged engine EGR dual-cycle cooling system mixes and cools compressed gas of a low-pressure stage compressor 32 and exhaust gas discharged from an EGR pipeline 7, and then the cooled gas is input into an intake intercooler 4 for cooling again. The interstage intercooler 5 is connected with the low-pressure stage compressor 32 and the EGR pipeline 7 through an air inlet three-way pipe (not shown).

The compressed gas of the low-pressure stage compressor 32 and the exhaust gas discharged from the EGR pipeline 7 are mixed in the cooling process of the interstage intercooler 5, the compressed gas of the low-pressure stage compressor 32 and the exhaust gas discharged from the EGR pipeline 7 are cooled and mixed in the interstage intercooler 5 and then enter the second cooling air channel 42 of the air intake intercooler 4 together to be cooled and mixed again, the exhaust gas and the fresh air are mixed more uniformly, the EGR mixer is omitted, and the production cost is reduced.

In some alternative embodiments: referring to fig. 1, the embodiment of the present application provides a two-stage supercharged engine EGR dual-cycle cooling system, and an EGR valve (not shown in the figure) for controlling opening and closing of the EGR pipe 7 is arranged on an EGR pipe 7 of the two-stage supercharged engine EGR dual-cycle cooling system. The EGR pipeline 7 is controlled to be opened and closed through the EGR valve, the EGR valve is opened when exhaust gas recirculation is needed, and the EGR valve is closed when the exhaust gas recirculation does not need to be carried out. A check valve (not shown) for preventing gas in the EGR pipe from flowing backward is provided between the EGR pipe 7 and the interstage intercooler 5. The check valve is used for preventing the air pressure of compressed air discharged by the low-pressure stage compressor 32 from being larger than the air pressure of waste gas discharged by the EGR pipeline 7, so that the waste gas flows back in the EGR pipeline 7, and the EGR rate of the engine is improved.

In a second aspect, embodiments of the present application provide an automobile using a two-stage supercharged engine EGR dual cycle cooling system according to any one of the embodiments described above.

Principle of operation

The embodiment of the application provides a two-stage supercharged engine EGR (exhaust gas recirculation) dual-cycle cooling system and an automobile, because the two-stage supercharged EGR engine hierarchical dual-cycle cooling system is provided with an engine 1, the engine 1 is provided with an air inlet pipeline 13 connected with an air inlet manifold 11 and an exhaust pipeline 14 connected with an exhaust manifold 12; a high-pressure stage supercharger 2, the high-pressure stage supercharger 2 including a high-pressure stage turbine 21 communicating with the exhaust line 14, and a high-pressure stage compressor 22 coaxially connected to the high-pressure stage turbine 21; a low-pressure stage supercharger 3, the low-pressure stage supercharger 3 including a low-pressure stage turbine 31 communicating with the high-pressure stage turbine 21, and a low-pressure stage compressor 32 coaxially connected to the low-pressure stage turbine 31; the air intake intercooler 4 is communicated with the high-pressure stage compressor 22, and compressed air of the high-pressure stage compressor 22 is cooled by the air intake intercooler 4 and then is input into the air intake manifold 11 through the air intake pipeline 13; and the interstage intercooler 5 is communicated with the low-pressure stage compressor 32, the interstage intercooler 5 cools the compressed gas of the low-pressure stage compressor 32 and then inputs the cooled compressed gas into the air intake intercooler 4, and the air intake intercooler 4 cools the compressed gas of the low-pressure stage compressor 32 again and then inputs the cooled compressed gas into the high-pressure stage compressor 22. And an EGR pipe 7, wherein the EGR pipe 7 communicates the exhaust manifold 12 with the intercooler 5, the intercooler 5 cools the exhaust gas discharged from the EGR pipe 7 and inputs the cooled exhaust gas into the intake intercooler 4, and the intake intercooler 4 cools the exhaust gas discharged from the EGR pipe 7 again and inputs the cooled exhaust gas into the high-pressure stage compressor 22.

Therefore, the low-pressure stage supercharger 3 of the two-stage supercharged engine EGR dual-cycle cooling system compresses fresh air through the low-pressure stage compressor 32, compressed gas discharged by the low-pressure stage compressor 32 and exhaust gas discharged by the EGR pipeline 7 enter the interstage intercooler 5, the interstage intercooler 5 cools the compressed gas of the low-pressure stage compressor 32 and the exhaust gas discharged by the EGR pipeline 7 and then inputs the cooled compressed gas and the cooled exhaust gas into the intake intercooler 4, and the intake intercooler 4 cools the compressed gas of the low-pressure stage compressor 32 and the exhaust gas discharged by the EGR pipeline 7 again and then inputs the cooled compressed gas and the cooled exhaust gas into the high-pressure stage compressor 22. The high-pressure stage compressor 22 compresses the compressed gas of the low-pressure stage compressor 32 and the exhaust gas discharged from the EGR pipeline 7 again, the compressed mixed gas discharged from the high-pressure stage compressor 22 enters the intake intercooler 4, and the intake intercooler 4 cools the compressed mixed gas of the high-pressure stage compressor 22 and then inputs the cooled compressed mixed gas into the intake manifold 11 through the intake pipeline 13 to participate in combustion. According to the air-conditioning system, compressed air discharged by the low-pressure-stage air compressor 32 and waste gas discharged by the EGR pipeline 7 are sequentially cooled by the interstage intercooler 5 and the air intake intercooler 4, and then enter the high-pressure-stage air compressor 22 for secondary cooling after being compressed again by the air intake intercooler 4, so that the air inlet temperature of an engine is greatly reduced, the air inlet amount and the air mixing ratio can be greatly improved, and the oil consumption of the engine is reduced.

In the description of the present application, it should be noted that the terms "upper", "lower", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for convenience in describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present application. Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

It is noted that, in the present application, relational terms such as "first" and "second", and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The above description is merely exemplary of the present application and is presented to enable those skilled in the art to understand and practice the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.