EGR system and vehicle

Abstract

The invention relates to the technical field of vehicles, and particularly discloses an EGR system and a vehicle, the EGR system comprises a supercharger, a back pressure valve and a waste gas circulation pipeline, the supercharger comprises a gas compressor and a turbine which are in transmission connection, the gas compressor is arranged on a gas inlet pipeline, and the turbine is arranged on a gas exhaust pipeline. The back pressure valve is arranged at the exhaust tail end of the exhaust pipeline and used for adjusting the pipeline pressure of the exhaust side of the turbine. The gas inlet end of the waste gas circulation pipeline communicates with the gas exhaust pipeline, the connecting position of the waste gas circulation pipeline and the gas exhaust pipeline is located between the gas exhaust side of the turbine and the back pressure valve, and the gas exhaust end of the waste gas circulation pipeline communicates with the gas inlet pipeline on the gas inlet side of the gas compressor. The integrated cooler and the EGR valve are sequentially arranged on the waste gas circulation pipeline from the gas inlet end to the gas exhaust end, so that waste gas can smoothly enter the gas inlet pipeline from the gas exhaust side of the turbine through the waste gas circulation pipeline, the situation that the operation working condition area of an engine is limited is reduced, and waste gas circulation can be smoothly carried out.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicles, and in particular to an EGR system and a vehicle. Background Art

[0002] During the use of natural gas engines, in order to reduce the combustion temperature in the cylinder and inhibit the formation of nitrogen oxides (NOx), equivalence ratio combustion technology is usually adopted and EGR technology (Exhaust Gas Re-circulation) is introduced. The principle is to reintroduce part of the exhaust gas after engine combustion into the intake side to participate in the combustion in the cylinder, thereby lowering the maximum combustion temperature in the cylinder, reducing the risk of knock and inhibiting the formation of nitrogen oxides.

[0003] In the prior art, engine EGR systems primarily draw air from the turbine, pass it through an EGR delivery line, and then introduce the exhaust gas into a mixer on the engine's intake line to mix with fresh air and fuel gas. However, this EGR system has significant drawbacks under certain engine operating conditions. In particular, when exhaust pressure is lower than intake pressure, EGR exhaust gas struggles to flow smoothly into the intake line, making EGR difficult to achieve. The engine's EGR operating range is narrow, easily restricted, and unable to meet all operating conditions. Summary of the Invention

[0004] The purpose of the present invention is to provide an EGR system and a vehicle to solve the problem in the related art that when the exhaust pressure of the EGR system is lower than the intake pressure, the exhaust gas has difficulty entering the intake pipe, which easily leads to a narrow engine operating range.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides an EGR system for an engine, the engine having an intake pipe and an exhaust pipe, the EGR system comprising:

[0007] The supercharger includes a compressor and a turbine that are transmission-connected, the compressor is arranged on the intake pipe, and the turbine is arranged on the exhaust pipe;

[0008] a back-pressure valve, the back-pressure valve being arranged at the exhaust end of the exhaust pipeline, the back-pressure valve being used to adjust the pipeline pressure on the exhaust side of the turbine;

[0009] An exhaust gas circulation pipeline, the intake end of the exhaust gas circulation pipeline is connected to the exhaust pipeline, and the connection position of the exhaust gas circulation pipeline and the exhaust pipeline is located between the exhaust side of the turbine and the back pressure valve, the exhaust end of the exhaust gas circulation pipeline is connected to the intake pipeline on the intake side of the compressor, and an integrated cooler and an EGR valve are sequentially arranged on the exhaust gas circulation pipeline from the intake end to the exhaust end.

[0010] In one embodiment, the integrated cooler includes a high-temperature cooler and a low-temperature cooler sequentially arranged from the air inlet end to the air outlet end of the exhaust gas flow pipe, and the outlet temperature of the high-temperature cooler is higher than the outlet temperature of the low-temperature cooler.

[0011] In one embodiment, the high-temperature cooler includes a first water circuit and a first gas circuit for mutual heat exchange, the first gas circuit is connected to the exhaust gas flow pipeline, and the first water circuit is connected to the circulating water circuit of the engine.

[0012] In one embodiment, the low-temperature stage cooler includes a second water circuit and a second air circuit for mutual heat exchange, the second air circuit is connected to the exhaust gas circulation pipeline, the second water circuit is a self-circulating water circuit, and the part of the second water circuit that is not for heat exchange with the second air circuit is provided with a flow regulating valve, a heat exchanger and a water pump.

[0013] In one embodiment, the integrated cooler further includes a condensate collector, which is used to collect condensate generated by the low-temperature stage cooler. The water outlet of the condensate collector is connected to the exhaust pipe, and the connection position between the condensate collector and the exhaust pipe is located on the exhaust side of the back pressure valve.

[0014] In one embodiment, the EGR system further comprises:

[0015] A first temperature sensor is used to detect the outlet temperature of the high-temperature cooler; and / or

[0016] The second temperature sensor is used to detect the outlet temperature of the low-temperature stage cooler.

[0017] In one embodiment, an after-processor is provided on the exhaust pipe, and the after-processor is located between the turbine and the back-pressure valve, and the connection position between the exhaust gas flow pipe and the exhaust pipe is located between the after-processor and the turbine.

[0018] In one embodiment, an EGR flow meter is provided on the exhaust gas flow pipeline, and the EGR flow meter is located between the integrated cooler and the EGR valve.

[0019] In a second aspect, the present invention provides a vehicle comprising an engine and the EGR system of any of the above schemes, wherein the engine and the EGR system are connected between the intake pipe and the exhaust pipe of the engine.

[0020] In one embodiment, the intake pipe of the engine is provided with an air filter, an intercooler, a throttle and a mixer, the air outlet of the mixer is connected to the combustion chamber of the engine through an intake manifold, and the compressor is arranged between the air filter and the throttle; the engine also has an intake branch, on which a gas cylinder, a vaporization pressure stabilizing mechanism and an injector are sequentially provided along the intake direction, and the air outlet of the injector is connected to the mixer.

[0021] The beneficial effects of the present invention are:

[0022] The present invention provides an EGR system and vehicle. The back-pressure valve of the EGR system is installed at the exhaust end of the exhaust pipe and is used to regulate the pipe pressure on the exhaust side of the turbine. By precisely adjusting the opening of the back-pressure valve, the pressure in the exhaust pipe can be increased, allowing the EGR exhaust gas to flow smoothly into the intake pipe. The EGR valve is installed in the exhaust gas circulation pipe to facilitate the regulation of the flow rate and flow area of ​​the EGR exhaust gas, providing an appropriate amount of EGR exhaust gas, and facilitating the optimization of combustion efficiency and the reduction of nitrogen oxide emissions. An integrated cooler is provided in the exhaust gas circulation pipe to cool the EGR exhaust gas. The cooled exhaust gas has a lower temperature, which can reduce the generation of nitrogen oxides and optimize combustion efficiency. Through the regulating effect of the back-pressure valve, the flow control of the EGR valve, and the temperature control of the integrated cooler, the EGR system effectively reduces the difficulty of exhaust gas entering the intake pipe due to the exhaust pressure being lower than the intake pressure, thereby expanding the engine's EGR operating range and improving the reliability and maintainability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic structural diagram of an EGR system according to an embodiment of the present invention;

[0024] Figure 2 Schematic diagram of the structure of the integrated cooler in an embodiment of the present invention.

[0025] In the picture:

[0026] 1. Supercharger; 11. Compressor; 12. Turbine;

[0027] 2. Back pressure valve; 3. Exhaust gas flow pipeline;

[0028] 4. Integrated cooler;

[0029] 41. High-temperature cooler; 411. First water path; 412. First gas path;

[0030] 42. Low-temperature stage cooler; 421. Second water path; 422. Second gas path; 423. Flow control valve; 424. Heat exchanger; 425. Water pump;

[0031] 43. Condensate collector; 44. Drain pipe; 45. Condensate control electromagnetic pump; 46. Partition;

[0032] 5. EGR valve; 6. EGR flow meter;

[0033] 7. Engine;

[0034] 71. Intake pipe; 711. Air filter; 712. Intercooler; 713. Throttle valve; 714. Mixer; 715. Intake manifold;

[0035] 72. Exhaust pipe; 721. After-processor;

[0036] 73. Intake branch; 731. Gas cylinder; 732. Vaporization pressure stabilizing mechanism; 733. Injector. DETAILED DESCRIPTION

[0037] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0038] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0039] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0040] In the description of this embodiment, terms such as "upper," "lower," "left," and "right" are used to refer to positions or locations based on those shown in the accompanying drawings. These terms are intended solely to facilitate description and simplify operation, and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0041] like Figures 1 to 2 As shown, an embodiment of the first aspect of the present invention provides an EGR system for an engine 7 having an intake line 71 and an exhaust line 72. The EGR system includes a supercharger 1, a backpressure valve 2, and an exhaust gas flow line 3. The supercharger 1 includes a compressor 11 and a turbine 12, which are connected in a transmission manner. The compressor 11 is disposed on the intake line 71, and the turbine 12 is disposed on the exhaust line 72. The backpressure valve 2 is disposed at the exhaust end of the exhaust line 72 and is used to regulate the line pressure on the exhaust side of the turbine 12. The intake end of the exhaust gas flow line 3 communicates with the exhaust line 72, and the connection between the exhaust gas flow line 3 and the exhaust line 72 is located between the exhaust side of the turbine 12 and the backpressure valve 2. The exhaust gas flow line 3 communicates with the intake line 71 on the intake side of the compressor 11. An integrated cooler 4 and an EGR valve 5 are disposed on the exhaust gas flow line 3 in sequence from the intake end to the exhaust end.

[0042] The supercharger 1 comprises a compressor 11 and a turbine 12, which are connected by a common shaft. The compressor 11, mounted on the intake line 71, compresses fresh air and delivers it to the cylinders of the engine 7, increasing the intake pressure and thereby boosting the power and efficiency of the engine 7. The turbine 12, mounted on the exhaust line 72, utilizes the exhaust energy from the engine 7 to rotate, thereby driving the compressor 11 and achieving efficient energy utilization.

[0043] The back-pressure valve 2 is installed at the exhaust end of the exhaust pipe 72 and is used to adjust the pipe pressure on the exhaust side of the turbine 12. By controlling the opening of the back-pressure valve 2, the pressure in the exhaust pipe 72 can be accurately adjusted. In particular, when the exhaust pressure is lower than the intake pressure, the back-pressure valve 2 can increase the pressure on the exhaust side, making it easier for the EGR exhaust gas to flow smoothly into the intake pipe 71, thereby expanding the EGR operating range of the engine 7.

[0044] The exhaust gas circulation line 3 is a channel connecting the exhaust line 72 and the intake line 71. Its intake end is connected to the exhaust line 72. The connection position is between the exhaust side of the turbine 12 and the back pressure valve 2. This allows the EGR exhaust gas to smoothly enter the exhaust gas circulation line 3 after passing through the turbine 12. The exhaust end of the exhaust gas circulation line 3 is connected to the intake line 71 on the intake side of the compressor 11. After cooling and flow regulation, the EGR exhaust gas can be mixed with fresh air and enter the cylinders of the engine 7 to participate in combustion. On the exhaust gas circulation line 3, an integrated cooler 4 and an EGR valve 5 are arranged in sequence from the intake end to the exhaust end. The integrated cooler 4 is responsible for cooling the EGR exhaust gas, reducing the exhaust gas temperature and reducing the generation of nitrogen oxides.

[0045] The EGR system of this embodiment achieves efficient and stable exhaust gas recirculation through the coordinated work of the supercharger 1, the back pressure valve 2 and the exhaust gas circulation pipeline 3. By adjusting the opening of the back pressure valve 2, the EGR exhaust gas can smoothly enter the intake pipeline 71 from the exhaust side of the turbine 12 through the exhaust gas circulation pipeline 3, and the exhaust gas temperature is adjusted by the integrated cooler 4 so that the exhaust gas reaches an appropriate temperature before entering the intake pipeline 71, which facilitates the smooth circulation of the exhaust gas, improves the combustion efficiency, reduces the generation of nitrogen oxides, and improves the performance and reliability of the engine 7.

[0046] It should be noted that the inventors have previously attempted to employ two EGR systems, with the first EGR system drawing air from the intake side of the turbine 12 and the second EGR system drawing air from the exhaust side of the turbine 12. However, the limited space for the overall structural layout of the engine 7 made it difficult to accommodate the complex dual systems. Furthermore, the complexity of the dual systems increased design, manufacturing, and maintenance costs, making their implementation difficult in practical applications. The EGR system of this embodiment, on the other hand, has a simple structure. It not only allows EGR exhaust gas to flow smoothly from the exhaust side of the turbine 12 through the exhaust gas flow line 3 into the intake line 71 at an appropriate temperature, but also has a simple structure that facilitates reduced layout space, allowing for flexible layout of the overall engine 7.

[0047] In some optional embodiments, the integrated cooler 4 includes a high-temperature cooler 41 and a low-temperature cooler 42 arranged in sequence from the air inlet end to the air outlet end of the exhaust gas circulation pipeline 3, and the outlet temperature of the high-temperature cooler 41 is higher than the outlet temperature of the low-temperature cooler 42.

[0048] In this embodiment, the high-temperature cooler 41 is located at the air inlet end of the exhaust gas circulation pipeline 3. It is the first cooling section through which the exhaust gas passes. Its main function is to initially reduce the temperature of the EGR exhaust gas. The outlet temperature of the high-temperature cooler 41 is higher than that of the low-temperature cooler 42 because its cooling intensity is relatively low. Its main purpose is to reduce the exhaust gas temperature to a relatively high level, but still higher than the dew point temperature under the local air pressure. This can prevent water vapor in the exhaust gas from condensing in the high-temperature cooler 41, avoid the generation of condensed water, and thus reduce the risk of blockage and corrosion. The low-temperature cooler 42 is located at the air outlet end of the exhaust gas circulation pipeline 3. It is a further cooling section after the exhaust gas passes through the high-temperature cooler 41. The cooling intensity of the low-temperature cooler 42 is relatively high, and its outlet temperature is lower than the outlet temperature of the high-temperature cooler 41. Through further cooling in the low-temperature cooler 42, the exhaust gas temperature is reduced to a temperature comparable to the fresh air intake temperature, which is significantly lower than the dew point of the exhaust gas at the local atmospheric pressure. This allows the water vapor in the exhaust gas to be fully liquefied in the low-temperature cooler 42, thereby effectively cooling the exhaust gas, further optimizing combustion efficiency, and reducing nitrogen oxide production. For example, the outlet temperature of the low-temperature cooler 42 can range from 30°C to 60°C. The integrated cooler 4 of this embodiment adopts a segmented design, including high- and low-temperature coolers 42, to facilitate sufficient heat exchange of the exhaust gas, precisely control the exhaust gas temperature, and ensure that the exhaust gas reaches an appropriate temperature before entering the intake pipe 71.

[0049] In some embodiments, the high-temperature cooler 41 includes a first water circuit 411 and a first gas circuit 412 for mutual heat exchange. The first gas circuit 412 is connected to the exhaust gas flow pipe 3 , and the first water circuit 411 is connected to the circulating water circuit of the engine 7 .

[0050] In this embodiment, the first gas path 412 is directly connected to the exhaust gas circulation pipeline 3 and is responsible for guiding the EGR exhaust gas through the high-temperature stage cooler 41. The exhaust gas flows in the first gas path 412 and exchanges heat with the coolant in the first water path 411. The coolant absorbs the heat of the exhaust gas, thereby reducing the temperature of the exhaust gas. The first water path 411 is connected to the circulating water path of the engine 7 and uses the coolant in the cooling system of the engine 7 to absorb the heat of the exhaust gas. This allows the high-temperature stage cooler 41 to utilize the existing cooling system of the engine 7 to improve the heat exchange efficiency, which not only improves the integration of the system, but also reduces the need for additional cooling equipment, reducing the complexity and cost of the system. The high-temperature stage cooler 41 can initially reduce the temperature of the EGR exhaust gas. The exhaust gas temperature at the outlet of the high-temperature stage cooler 41 is higher than the dew point temperature under the local air pressure to reduce the generation of condensed water. Condensed water may cause system blockage and corrosion, affecting the normal operation of the EGR system.

[0051] In some embodiments, the low-temperature stage cooler 42 includes a second water circuit 421 and a second gas circuit 422 for mutual heat exchange, the second gas circuit 422 is connected to the exhaust gas circulation pipeline 3, the second water circuit 421 is a self-circulating water circuit, and the part of the second water circuit 421 that does not exchange heat with the second gas circuit 422 is provided with a flow regulating valve 423, a heat exchanger 424 and a water pump 425.

[0052] In this embodiment, the second air path 422 is connected to the exhaust gas flow line 3 and is responsible for guiding the EGR exhaust gas, which has been initially cooled by the high-temperature stage cooler 41, through the low-temperature stage cooler 42. The exhaust gas flows in the second air path 422 and exchanges heat with the coolant in the second water path 421, further reducing the exhaust gas temperature. The second water path 421 is an independent self-circulating water path, not connected to the main circulating water path of the engine 7. This allows the low-temperature stage cooler 42 to independently control the coolant temperature and flow rate to adapt to different operating conditions. For example, the first water path 411 of the high-temperature cooler and the second water path 421 of the low-temperature cooler can be separated by a partition 46.

[0053] The main function of the low-temperature stage cooler 42 is to further reduce the temperature of the EGR exhaust gas to a level equivalent to the fresh air intake temperature, thereby optimizing combustion efficiency and reducing nitrogen oxide emissions. When the EGR exhaust gas enters the second gas path 422, its temperature undergoes heat exchange with the coolant in the second water path 421. The coolant absorbs the heat of the exhaust gas, further reducing the exhaust gas temperature. The low-temperature stage cooler 42 can effectively reduce the exhaust gas temperature to a level equivalent to the fresh air intake temperature, optimizing combustion efficiency. The second water path 421 is a self-circulating water path that does not rely on the main circulating water path of the engine 7, allowing the low-temperature stage cooler 42 to independently control the temperature and flow of the coolant to adapt to different operating conditions. In the second water path 421, a flow regulating valve 423, a heat exchanger 424 and a water pump 425 are provided on the part of the water path that does not exchange heat with the second gas path 422. Flow control valve 423 is used to precisely control the coolant flow rate to ensure heat exchange efficiency. Heat exchanger 424 is used to dissipate heat from the coolant to the environment, maintaining the coolant's low temperature. Heat exchanger 424 can be, but is not limited to, a wind-water heat exchanger. Water pump 425 provides power to drive the coolant through the self-circulating water circuit, facilitating accurate regulation of the heat exchange rate and achieving precise temperature control. This not only improves heat exchange efficiency, but also optimizes combustion efficiency, reduces nitrogen oxide emissions, and enhances system reliability and maintainability.

[0054] In some embodiments, the integrated cooler 4 also includes a condensate collector 43, which is used to collect condensate generated by the low-temperature cooler 42. The water outlet of the condensate collector 43 is connected to the exhaust pipe 72, and the connection position between the condensate collector 43 and the exhaust pipe 72 is located on the exhaust side of the back pressure valve 2.

[0055] In this embodiment, the condensate collector 43 is part of the integrated cooler 4 and can be located at the bottom of the low-temperature stage cooler 42 to collect condensate generated by the reduced exhaust gas temperature in the low-temperature stage cooler 42. The outlet of the condensate collector 43 is connected to the exhaust line 72 and is located on the exhaust side of the back-pressure valve 2. This allows the condensate to be smoothly discharged from the system and prevents accumulation within the cooler.

[0056] In the low-temperature stage cooler 42, the exhaust gas temperature is reduced to a temperature far below the dew point temperature at the local air pressure, causing the water vapor in the exhaust gas to condense into liquid water. The condensate collector 43 can collect this condensate to prevent it from accumulating in the cooler, thereby avoiding system blockage and corrosion. The outlet of the condensate collector 43 is connected to the exhaust pipe 72, and the connection position is located on the exhaust side of the back pressure valve 2, so that the condensate can be smoothly discharged from the system and enter the exhaust pipe 72. In the exhaust pipe 72, the condensate will be vaporized into gas and discharged together with the exhaust gas and eventually discharged into the atmosphere, which not only solves the problem of condensate treatment, but also avoids the additional drain pipe 44 and simplifies the system structure. By effectively treating the condensate, the condensate collector 43 improves the reliability and maintainability of the entire EGR system, reduces the risk of system blockage and corrosion caused by condensate accumulation, and facilitates the stable operation of the EGR system under different working conditions.

[0057] Optionally, the outlet of the condensate collector 43 is connected to the exhaust line 72 via a drain pipe 44. A condensate control electromagnetic pump 45 is provided on the drain pipe 44. The pressure head of the condensate control electromagnetic pump 45 is greater than the sum of the back pressure of the exhaust line 72 and the flow resistance of the drain pipe 44. This facilitates the smooth discharge of condensate, reduces accumulation in the low-temperature cooler, and reduces the risk of system blockage and corrosion. Exhaust pipe back pressure refers to the pressure in the exhaust line 72 of the engine 7. The flow resistance of the condensate drain pipe 44 refers to the resistance generated when the condensate flows in the drain pipe 44, including pipe friction loss and local resistance. The resistance generated when the condensate flows in the drain pipe 44 depends on the length, diameter, and material of the pipe, as well as the flow rate and flow velocity of the condensate. The pressure head of the condensate control electromagnetic pump 45 refers to the maximum pressure that the pump can provide, usually expressed as head height, such as meters of water column.

[0058] In some embodiments, an after-processor 721 is provided on the exhaust pipe 72 , and the after-processor 721 is located between the turbine 12 and the back-pressure valve 2 , and the connection position between the exhaust gas flow pipe 3 and the exhaust pipe 72 is located between the after-processor 721 and the turbine 12 .

[0059] In this embodiment, the after-processor 721 is an important component in the exhaust pipe 72, located between the turbine 12 and the back-pressure valve 2. It is mainly used to further process the exhaust gas discharged by the engine 7 to reduce the emission of harmful gases, such as nitrogen oxides and particulate matter. The after-processor 721 may include a catalytic converter and a particulate filter, which can effectively reduce the pollutant content in the exhaust gas. The after-processor 721 is installed between the turbine 12 and the back-pressure valve 2, so that the exhaust gas can be processed by the after-processor 721 after passing through the turbine 12, and then discharged through the back-pressure valve 2, so that the after-processor 721 can process the high-temperature exhaust gas after passing through the turbine 12, thereby improving the processing efficiency.

[0060] The intake end of the exhaust gas flow line 3 is connected to the exhaust line 72, and the connection point is located between the after-processor 721 and the turbine 12. This allows the EGR exhaust gas to be removed for recirculation after passing through the turbine 12 but before entering the after-processor 721. The intake end of the exhaust gas flow line 3 is connected to the exhaust line 72 between the after-processor 721 and the turbine 12 because the exhaust gas removed after the turbine 12 and before the after-processor 721 has a relatively high temperature, but has undergone preliminary cooling by the turbine 12 and is suitable for recirculation into the EGR system. By removing the exhaust gas before the after-processor 721, interference with the processing efficiency of the after-processor 721 is reduced, allowing the after-processor 721 to effectively treat the remaining exhaust gas.

[0061] In some embodiments, an EGR flow meter 6 is provided on the exhaust gas circulation pipeline 3 , and the EGR flow meter 6 is located between the integrated cooler 4 and the EGR valve 5 .

[0062] In this embodiment, an EGR flowmeter 6 is installed on the exhaust gas flow line 3, located between the integrated cooler 4 and the EGR valve 5. The EGR flowmeter 6 monitors the flow rate of EGR exhaust gas after cooling by the integrated cooler 4 in real time. By installing the flowmeter between the cooler and the EGR valve 5, the measured flow rate is the actual flow rate after cooling, providing accurate data for the engine 7 control system. The EGR flowmeter 6 is positioned so that it can work in conjunction with the EGR valve 5. The EGR valve 5 dynamically adjusts the flow rate of EGR exhaust gas based on the operating conditions of the engine 7. The EGR flowmeter 6 provides real-time flow data, facilitating improved adjustment accuracy and response speed of the EGR valve 5. By accurately measuring flow rate, this embodiment allows the engine 7 control system to dynamically adjust the opening of the EGR valve 5 to ensure that the engine 7 receives the appropriate amount of EGR exhaust gas under different operating conditions, thereby optimizing combustion efficiency, reducing nitrogen oxide emissions, and ensuring stable operation of the engine 7 under different operating conditions. If the flowmeter detects abnormal flow rate, it can also facilitate timely detection of system problems such as EGR valve 5 failure or pipeline blockage, thereby improving system maintainability and reliability.

[0063] Optionally, a second EGR flowmeter 6 may be provided on the outlet side of the EGR valve 5. The second EGR flowmeter 6 is disposed on the exhaust gas flow line 3 and is capable of monitoring the EGR exhaust gas flow rate after adjustment by the EGR valve 5 in real time. By installing the second EGR flowmeter 6 on the outlet side of the EGR valve 5, the actual flow rate after adjustment by the EGR valve 5 can be measured, and more accurate data can be provided to the engine 7 control system, thereby improving the adjustment accuracy of the EGR valve 5. If the EGR flowmeter 6 malfunctions or the data is abnormal, the second EGR flowmeter 6 can serve as a backup to facilitate normal operation of the system.

[0064] In some embodiments, the EGR system further includes: a first temperature sensor and / or a second temperature sensor, wherein the first temperature sensor is used to detect the outlet temperature of the high-temperature stage cooler 41 and the second temperature sensor is used to detect the outlet temperature of the low-temperature stage cooler 42 .

[0065] In this embodiment, the first temperature sensor can be installed at the outlet of the high-temperature stage cooler 41, so that the first temperature sensor can monitor the temperature of the EGR exhaust gas after being cooled by the high-temperature stage cooler 41 in real time. By accurately measuring the temperature, the engine 7 control system can ensure that the exhaust gas temperature is higher than the dew point temperature under the local air pressure to prevent the generation of condensed water. By monitoring the outlet temperature of the high-temperature stage cooler 41, the engine 7 control system can dynamically adjust the opening of the back pressure valve 2 to improve the operating efficiency of the EGR system and facilitate the stable operation of the system under different working conditions. The first temperature sensor can also be used for system fault diagnosis. If the temperature reading is abnormal, problems in the system, such as cooler failure, pipe blockage, etc., can be discovered in time, thereby improving the maintainability and reliability of the system.

[0066] A second temperature sensor can be installed at the outlet of low-temperature cooler 42, enabling the second temperature sensor to monitor the temperature of the EGR exhaust gas after it has been cooled by low-temperature cooler 42 in real time. By accurately measuring the temperature, the engine 7 control system can ensure that the exhaust gas temperature is comparable to the fresh air intake temperature, optimizing combustion efficiency and reducing nitrogen oxide emissions. By monitoring the outlet temperature of low-temperature cooler 42, the engine 7 control system can also dynamically adjust the opening of EGR valve 5 and regulate operating efficiency, facilitating stable operation of the system under different operating conditions. The second temperature sensor can also be used for system fault diagnosis. If the temperature reading is abnormal, system problems such as cooler failure or pipe blockage can be promptly identified, thereby improving the maintainability and reliability of the system.

[0067] An embodiment of the second aspect of the present application provides a vehicle, including an engine 7 and any of the above-mentioned EGR systems. The engine 7 and the EGR system are connected between the intake pipe 71 and the exhaust pipe 72 of the engine 7. The vehicle cooperates with the EGR system through the engine 7, and the back pressure valve 2 and the EGR valve 5 work together to facilitate the smooth flow of EGR exhaust gas into the intake pipe 71, expand the EGR operating condition area, reduce the combustion temperature, and reduce the generation of nitrogen oxides. By precisely controlling the EGR exhaust gas flow and temperature, the engine 7 can operate efficiently under different operating conditions and improve fuel economy.

[0068] In some embodiments, the intake line 71 of the engine 7 is provided with an air filter 711, an intercooler 712, a throttle valve 713, and a mixer 714. The outlet of the mixer 714 is connected to the combustion chamber of the engine 7 via an intake manifold 715. The compressor 11 is provided between the air filter 711 and the throttle valve 713. The engine 7 also has an intake branch 73. The intake branch 73 is provided with a gas cylinder 731, a vaporization pressure stabilizing mechanism 732, and an injector 733 in sequence along the intake direction. The outlet of the injector 733 is connected to the mixer 714.

[0069] In this embodiment, the air filter 711 filters fresh air entering the engine 7, removing dust and impurities and protecting the internal components of the engine 7 from wear. The throttle valve 713, located after the compressor 11, controls the amount of air entering the engine 7. By adjusting the opening of the throttle valve 713, the power output of the engine 7 can be controlled. The outlet of the mixer 714 communicates with the combustion chamber of the engine 7 through the intake manifold 715. The mixer 714 mixes fresh air with exhaust gas (EGR) so that the mixed gas enters the combustion chamber evenly, optimizing the combustion process. The gas cylinder 731 can be used to store natural gas or other fuel gas and can provide fuel for the engine 7. The vaporization and pressure stabilization mechanism 732, located after the gas cylinder 731, facilitates vaporization and stabilization of the fuel gas in the gas cylinder 731, ensuring that the fuel gas is in a suitable state before entering the injector 733. The injector 733 is the terminal component of the intake branch 73, and its outlet communicates with the mixer 714. The function of the injector 733 is to precisely inject the fuel gas into the mixer 714 to mix with the fresh air to form a uniform mixed gas, which then enters the combustion chamber for combustion.

[0070] The intake duct 71 and intake branch 73 of the engine 7 of this embodiment facilitate efficient mixing and delivery of fresh air and fuel gas. The air filter 711, compressor 11, throttle valve 713, and mixer 714 work together in the intake duct 71 to provide high-pressure, clean intake air and optimize combustion efficiency. The gas cylinder 731, vaporization pressure stabilization mechanism 732, and injector 733 in the intake branch 73 ensure a stable supply and precise injection of fuel gas, improving the performance and efficiency of the engine 7 while also optimizing the combustion process and reducing pollutant emissions.

[0071] Since the vehicle includes the above-mentioned EGR system, the vehicle according to the embodiment of the present invention has all the advantages and beneficial effects of the above-mentioned embodiments, which will not be described in detail here.

[0072] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. An EGR system for an engine having an intake pipe and an exhaust pipe, characterized in that: The EGR system includes: The supercharger includes a compressor and a turbine that are transmission-connected, the compressor is arranged on the intake pipe, and the turbine is arranged on the exhaust pipe; a back-pressure valve, the back-pressure valve being arranged at the exhaust end of the exhaust pipeline, the back-pressure valve being used to adjust the pipeline pressure on the exhaust side of the turbine; An exhaust gas circulation pipeline, the intake end of the exhaust gas circulation pipeline is connected to the exhaust pipeline, and the connection position of the exhaust gas circulation pipeline and the exhaust pipeline is located between the exhaust side of the turbine and the back pressure valve, the exhaust end of the exhaust gas circulation pipeline is connected to the intake pipeline on the intake side of the compressor, and an integrated cooler and an EGR valve are sequentially arranged on the exhaust gas circulation pipeline from the intake end to the exhaust end.

2. The EGR system according to claim 1, characterized in that The integrated cooler includes a high-temperature cooler and a low-temperature cooler sequentially arranged from the air inlet end to the air outlet end of the exhaust gas flow pipeline, and the outlet temperature of the high-temperature cooler is higher than the outlet temperature of the low-temperature cooler.

3. The EGR system according to claim 2, characterized in that: The high-temperature stage cooler includes a first water circuit and a first gas circuit for exchanging heat with each other, the first gas circuit is communicated with the exhaust gas flow pipeline, and the first water circuit is communicated with a circulating water circuit of the engine.

4. The EGR system according to claim 2, characterized in that: The low-temperature stage cooler includes a second water circuit and a second air circuit for mutual heat exchange, the second air circuit is connected to the exhaust gas circulation pipeline, the second water circuit is a self-circulating water circuit, and the part of the second water circuit that does not exchange heat with the second air circuit is provided with a flow regulating valve, a heat exchanger and a water pump.

5. The EGR system according to claim 2, characterized in that: The integrated cooler also includes a condensate collector, which is used to collect condensate generated by the low-temperature cooler. The water outlet of the condensate collector is connected to the exhaust pipe, and the connection position between the condensate collector and the exhaust pipe is located on the exhaust side of the back pressure valve.

6. The EGR system according to claim 2, characterized in that: The EGR system further includes: A first temperature sensor is used to detect the outlet temperature of the high-temperature cooler; and / or The second temperature sensor is used to detect the outlet temperature of the low-temperature stage cooler.

7. The EGR system according to any one of claims 1 to 6, characterized in that: An after-processor is provided on the exhaust pipe, and the after-processor is located between the turbine and the back-pressure valve. The connection position between the exhaust gas flow pipe and the exhaust pipe is located between the after-processor and the turbine.

8. The EGR system according to any one of claims 1 to 6, characterized in that: An EGR flow meter is provided on the exhaust gas flow pipeline, and the EGR flow meter is located between the integrated cooler and the EGR valve.

9. A vehicle, characterized in that: The invention comprises an engine and the EGR system according to any one of claims 1 to 8, wherein the engine and the EGR system are connected between the intake pipe and the exhaust pipe of the engine.

10. The vehicle according to claim 9, characterized in that The intake pipe of the engine is provided with an air filter, an intercooler, a throttle and a mixer. The air outlet of the mixer is connected to the combustion chamber of the engine through the intake manifold, and the compressor is arranged between the air filter and the throttle; the engine also has an intake branch, on which a gas cylinder, a vaporization pressure stabilizing mechanism and an injector are sequentially arranged along the intake direction, and the air outlet of the injector is connected to the mixer.

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