Engine low-pressure exhaust gas recirculation system, engine and vehicle
By setting the EGR intake point at the intake end of the catalytic converter and using components such as pressure regulating valves, the proportion of waste gas reuse in the low-pressure EGR system is improved, the problem of low waste gas reuse ratio is solved, and the engine fuel consumption rate is reduced and the fuel economy is improved.
Patent Information
- Application Number
- CN202421617225.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-09
- Publication Date
- 2025-04-01
- Estimated Expiration
- 2034-07-09
AI Technical Summary
In the existing low-pressure EGR system, the proportion of exhaust gas reuse is relatively low, which limits the reduction of engine fuel consumption.
By setting the EGR intake air intake point at the intake end of the catalytic converter, and using components such as pressure regulating valve, EGR cooler, condenser and three-way valve, the intake pressure is increased, thereby increasing the proportion of waste gas reuse.
The proportion of waste gas reuse is increased, the engine fuel consumption rate is reduced, the fuel economy is improved, and the risk of EGR cooler cracking caused by condensate reflux is avoided.
Smart Images
Figure CN222702059U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of automobile manufacturing, in particular to an engine low-pressure exhaust gas recirculation system, an engine and a vehicle. Background Art
[0002] In order to cope with increasingly stringent fuel consumption and emission regulations, major automobile manufacturers are exploring new technologies, such as VVL (variable valve lift) technology, cylinder deactivation technology, low-friction cylinder technology, etc. Among them, EGR (exhaust gas recirculation) technology has superior performance in energy conservation and emission reduction, and is increasingly widely used in small gasoline passenger cars.
[0003] EGR is to reduce the tendency of explosion and reduce fuel consumption by reintroducing part of the engine's exhaust gas into the engine's intake air. The commonly used EGR schemes are usually divided into high-pressure EGR systems and low-pressure EGR systems according to the pressure of the exhaust gas intake point.
[0004] The intake and air intake point of the high-pressure EGR system is usually before the exhaust gas flows through the turbine. At this time, the content of combustible gases such as HC and CO in the exhaust gas is high, but the concentration of soot particles and the temperature of the gas are high, and the pressure fluctuates greatly. The valve body and control requirements in the EGR system are relatively stringent, and the cost is high. The intake and air intake point of the low-pressure EGR system is usually in the catalytic converter. At this time, the content of combustible gases such as HC and CO in the exhaust gas is low, the concentration of soot particles is low, and the pressure is relatively stable, which can appropriately reduce the cost of the EGR system.
[0005] The primary condition for the EGR system to achieve exhaust gas recirculation is that the pressure at the intake point is higher than that at the outlet. The exhaust gas intake point of the conventional low-pressure EGR system is in the middle of the catalytic converter, and the intake pressure is relatively low, which limits the proportion of exhaust gas reuse. Summary of the invention
[0006] The technical problem to be solved by the utility model is to provide an engine low-pressure exhaust gas recirculation system, an engine and a vehicle which can increase the proportion of exhaust gas reuse and reduce the fuel consumption rate of the engine.
[0007] In order to solve the above technical problems, the utility model adopts the following technical solutions:
[0008] A low-pressure exhaust gas recirculation system of an engine, comprising a pressure regulating valve, an intake pipe, a turbocharger, an exhaust pipe, an EGR control valve, an EGR cooler and a catalytic converter, wherein the pressure regulating valve is arranged upstream of a main channel of the intake pipe, and the main channel of the intake pipe is downstream connected to an air inlet of a compressor of the turbocharger, an air outlet of a turbine of the turbocharger is connected to one end of the exhaust pipe, and the other end of the exhaust pipe is connected to an air inlet end of the catalytic converter, an EGR air intake pipe is provided at the air inlet end of the catalytic converter, and the EGR air intake pipe is connected to an air inlet of the EGR cooler, an air outlet of the EGR cooler is connected to the EGR control valve, and the EGR control valve is connected to a bypass channel of the intake pipe.
[0009] Preferably, the installation position of the EGR cooler is lower than the position of the EGR air intake pipe.
[0010] Preferably, the engine low-pressure exhaust gas recirculation system also includes a condenser, which is located lower than the installation position of the EGR cooler; the condenser is connected to the EGR cooler when the engine is stopped, and the condenser is not connected to the EGR cooler when the engine is running.
[0011] Preferably, the condenser is arranged on the catalytic converter and is connected to the interior of the catalytic converter.
[0012] Preferably, a three-way catalytic converter and a particulate trap are provided inside the catalytic converter, and the condenser is located between the three-way catalytic converter and the particulate trap or at the rear end of the particulate trap.
[0013] Preferably, the condenser is arranged on the downstream pipeline of the catalytic converter and is connected to the downstream pipeline of the catalytic converter.
[0014] Preferably, the engine low-pressure exhaust gas recirculation system also includes a three-way valve, a first channel of the three-way valve is connected to the EGR air intake pipe, a second channel of the three-way valve is connected to the condenser, and a third channel of the three-way valve is connected to the air inlet of the EGR cooler.
[0015] Preferably, the EGR cooler is arranged with one end of the air inlet tilted downward; and the condenser is arranged with one end connected to the three-way valve tilted upward.
[0016] An engine comprises the engine low-pressure exhaust gas recirculation system as described in any one of the above items.
[0017] A vehicle comprises the engine described above.
[0018] The beneficial technical effect of the utility model is that the above-mentioned engine low-pressure exhaust gas recirculation system can increase the intake pressure by setting the EGR intake point at the intake end of the catalytic converter, thereby increasing the proportion of exhaust gas recycling, reducing the engine fuel consumption rate, and thus improving fuel economy. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 It is a structural block diagram of an engine low-pressure exhaust gas recirculation system in one embodiment of the utility model;
[0020] Figure 2 This is a structural block diagram of an engine low-pressure exhaust gas recirculation system in another embodiment of the utility model. DETAILED DESCRIPTION
[0021] In order to enable ordinary technicians in the field to more clearly understand the purpose, technical solutions and advantages of the utility model, the utility model is further explained below in conjunction with the accompanying drawings and embodiments.
[0022] like Figure 1 As shown, in one embodiment of the utility model, the engine low-pressure exhaust gas recirculation system includes a pressure regulating valve 10, an intake pipe 20, a turbocharger 30, an exhaust pipe 70, an EGR control valve 40, an EGR cooler 50 and a catalytic converter 60, wherein the catalytic converter 60 is provided with a three-way catalytic converter 61 and a particulate trap 62.
[0023] The pressure regulating valve 10 is arranged upstream of the main channel of the intake pipe 20, and the downstream of the main channel of the intake pipe 20 is connected to the air inlet of the compressor 31 of the turbocharger 30, the air outlet of the turbine 32 of the turbocharger 30 is connected to one end of the exhaust pipe 70, and the other end of the exhaust pipe 70 is connected to the air inlet end of the catalytic converter 60, and the air inlet end of the catalytic converter 60 is provided with an EGR air intake pipe 63, and the EGR air intake pipe 63 is connected to the air inlet of the EGR cooler 50, and the air outlet of the EGR cooler 50 is connected to the EGR control valve 40, and the EGR control valve 40 is connected to the bypass channel of the intake pipe 20.
[0024] The working principle of the engine low-pressure exhaust gas recirculation system in this embodiment is as follows:
[0025] When the engine is running, the exhaust gas discharged by the engine is discharged from the outlet of the turbine 32 of the turbocharger 30 and enters the catalytic converter 60 through the exhaust pipe 70. At this time, the EGR control valve 40 is in an open state. By adjusting the opening of the pressure regulating valve 10, it is ensured that there is enough pressure difference in path A (EGR air intake pipe 63-EGR cooler 50-EGR control valve 40-intake pipe 20). At this time, part of the engine exhaust gas enters the intake pipe 20 through path A, and the fresh air is mixed with the exhaust gas after passing through the pressure regulating valve 10, and then enters the compressor 31 of the turbocharger 30, and enters the engine after being pressurized.
[0026] The engine low-pressure exhaust gas recirculation system in this embodiment can increase the intake pressure by setting the EGR air intake point at the intake end of the catalytic converter, thereby increasing the proportion of exhaust gas recycling, reducing the engine fuel consumption rate, and thus improving fuel economy.
[0027] like Figure 2 As shown, in another embodiment of the utility model, the engine low-pressure exhaust gas recirculation system includes a pressure regulating valve 10, an intake pipe 20, a turbocharger 30, an exhaust pipe 70, an EGR control valve 40, an EGR cooler 50, a catalytic converter 60 and a three-way valve 80, wherein the catalytic converter 60 is provided with a three-way catalytic converter 61 and a particulate trap 62.
[0028] The pressure regulating valve 10 is arranged upstream of the main channel of the intake pipe 20, and the downstream of the main channel of the intake pipe 20 is connected to the air inlet of the compressor 31 of the turbocharger 30, and the air outlet of the turbine 32 of the turbocharger 30 is connected to one end of the exhaust pipe 70, and the other end of the exhaust pipe 70 is connected to the air inlet end of the catalytic converter 60; the air inlet end of the catalytic converter 60 is provided with an EGR air intake pipe 63, and the catalytic converter 60 is also provided with a condenser 64, which The EGR air intake pipe 63 is connected to the first channel of the three-way valve 80, the condenser pipe 64 is connected to the second channel of the three-way valve 80, the third channel of the three-way valve 80 is connected to the air inlet of the EGR cooler 50, the air outlet of the EGR cooler 50 is connected to the EGR control valve 40, and the EGR control valve 40 is connected to the bypass channel of the intake pipe 20. Due to the limitation of the system layout, the installation position of the EGR cooler 50 is lower than the position of the EGR air intake pipe 63.
[0029] In other embodiments of the utility model, the condenser 64 can be located at the rear end of the particulate trap 62 or other positions of the catalytic converter 60, and the condenser 64 can also be set in the downstream pipeline of the catalytic converter 60, as long as the position of the condenser 64 is ensured to be lower than the installation position of the EGR cooler 50.
[0030] Compared with the EGR cooler 50 in the present embodiment which is connected to the EGR air intake pipe 63 and the condenser pipe 64 respectively through the three-way valve 80, in other embodiments of the utility model, the EGR cooler 50 can be provided with two air inlets which are connected to the EGR air intake pipe 63 and the condenser pipe 64 respectively, and at the same time, through valve control, the condenser pipe 64 is connected to the EGR cooler 50 when the engine is stopped, and is not connected to the EGR cooler 50 when the engine is running.
[0031] In order to ensure that the condensed water can smoothly enter the catalytic converter 60, the EGR cooler 50 is set with one end of the air inlet tilted downward, and the condenser 64 is set with the end connected to the three-way valve 80 tilted upward, and the position of the three-way valve 80 is lower than the air inlet position of the EGR cooler 50, and the position of the three-way valve 80 is higher than the position of the condenser 64.
[0032] The working principle of the engine low-pressure exhaust gas recirculation system in this embodiment is as follows:
[0033] When the engine is running, the exhaust gas discharged by the engine is discharged from the outlet of the turbine 32 of the turbocharger 30 and enters the catalytic converter 60 through the exhaust pipe 70. At this time, the EGR control valve 40 is in the open state, and the three-way valve 80 is switched to the intake state, connecting the EGR air intake pipe 63 and the EGR cooler 50. By adjusting the opening of the pressure regulating valve 10, it is ensured that the path A (EGR air intake pipe 63-three-way valve 80-EGR cooler 50-EGR control valve 40-intake pipe 20) has sufficient pressure difference. At this time, part of the engine exhaust gas enters the intake pipe 20 through the path A, and the fresh air is mixed with the exhaust gas after passing through the pressure regulating valve 10, and then enters the compressor 31 of the turbocharger 30, and enters the engine after being pressurized.
[0034] When the engine is stopped, the three-way valve 80 is switched to the condensate discharge state, connecting the condensate pipe 64 and the EGR cooler 50. As the temperature of the mixed air in the intake pipe 20 drops, the water vapor contained in the mixed air gradually forms condensate, which enters the catalytic converter 60 through path B (intake pipe 20—EGR control valve 40—EGR cooler 50—three-way valve 80—condensate pipe 64) and is then discharged out of the vehicle through the exhaust pipe of the entire vehicle.
[0035] The engine low-pressure exhaust gas recirculation system in this embodiment has the following beneficial technical effects:
[0036] 1. By setting the EGR air intake point at the front end of the catalytic converter, the intake pressure can be increased, thereby increasing the proportion of exhaust gas recycling, reducing the engine fuel consumption rate, and thus improving fuel economy.
[0037] 2. By adding a three-way valve and a condenser pipe, during the operation of the engine, the three-way valve connects the EGR air intake pipe and the EGR cooler, and the exhaust gas in the EGR system can directly enter the engine through the pipeline and the EGR cooler; when the engine is stopped, the three-way valve connects the condenser pipe and the EGR cooler, and the exhaust gas in the EGR system gradually cools down and the condensed water generated enters the catalytic converter and finally flows to the outside of the vehicle along the exhaust pipe of the whole vehicle, avoiding the condensed water from flowing back and staying in the EGR cooler, and further avoiding the situation where the EGR cooler cracks due to the expansion of the condensed water freezing, thereby ensuring the emission performance of the engine.
[0038] 3. Set the EGR cooler with one end of the air inlet tilted downward, and set the condenser with the end connected to the three-way valve tilted upward, and make the position of the three-way valve lower than the air inlet position of the EGR cooler and higher than the position of the condenser, so as to ensure that the condensed water can smoothly enter the catalytic converter and finally flow out of the vehicle along the exhaust pipe of the whole vehicle.
[0039] The utility model also provides an engine, which comprises the engine low-pressure exhaust gas recirculation system mentioned above.
[0040] The utility model also provides a vehicle, and the vehicle comprises the engine mentioned above.
[0041] The above description is only a preferred embodiment of the utility model, and does not limit the utility model in any form. Those skilled in the art can make various equivalent changes and improvements based on the above embodiments, and all equivalent changes or modifications made within the scope of the claims should fall within the protection scope of the utility model.
Claims
1. An engine low-pressure exhaust gas recirculation system, characterized in that: The invention comprises a pressure regulating valve, an intake pipe, a turbocharger, an exhaust pipe, an EGR control valve, an EGR cooler and a catalytic converter, wherein the pressure regulating valve is arranged upstream of a main channel of the intake pipe, the main channel downstream of the intake pipe is connected to an air inlet of a compressor of the turbocharger, an air outlet of a turbine of the turbocharger is connected to one end of the exhaust pipe, the other end of the exhaust pipe is connected to an air inlet end of the catalytic converter, an EGR air intake pipe is arranged at an air inlet end of the catalytic converter, the EGR air intake pipe is connected to an air inlet end of the EGR cooler, an air outlet end of the EGR cooler is connected to the EGR control valve, and the EGR control valve is connected to a bypass channel of the intake pipe.
2. The engine low-pressure exhaust gas recirculation system according to claim 1, characterized in that: The installation position of the EGR cooler is lower than the position of the EGR air intake pipe.
3. The engine low-pressure exhaust gas recirculation system according to claim 2, characterized in that: The engine low-pressure exhaust gas recirculation system also includes a condenser, which is located lower than the installation position of the EGR cooler; the condenser is connected to the EGR cooler when the engine is stopped, and is not connected to the EGR cooler when the engine is running.
4. The engine low-pressure exhaust gas recirculation system as claimed in claim 3, characterized in that: The condenser is disposed on the catalytic converter and is communicated with the interior of the catalytic converter.
5. The engine low-pressure exhaust gas recirculation system as claimed in claim 4, characterized in that: A three-way catalytic converter and a particulate trap are arranged inside the catalytic converter, and the condenser is located between the three-way catalytic converter and the particulate trap or at the rear end of the particulate trap.
6. The engine low-pressure exhaust gas recirculation system as claimed in claim 3, characterized in that: The condenser is arranged on the downstream pipeline of the catalytic converter and is connected to the downstream pipeline of the catalytic converter.
7. The engine low-pressure exhaust gas recirculation system according to any one of claims 3 to 6, characterized in that: The engine low-pressure exhaust gas recirculation system also includes a three-way valve, a first channel of the three-way valve is connected to the EGR air intake pipe, a second channel of the three-way valve is connected to the condenser, and a third channel of the three-way valve is connected to the air inlet of the EGR cooler.
8. The engine low-pressure exhaust gas recirculation system according to claim 7, characterized in that: The EGR cooler is arranged with one end of the air inlet tilted downward; the condenser is arranged with one end connected to the three-way valve tilted upward.
9. An engine, characterized in that: The engine comprises an engine low-pressure exhaust gas recirculation system as described in any one of claims 1-8.
10. A vehicle, characterized in that: The vehicle includes the engine as claimed in claim 9.