Exhaust gas recirculation cooling system and control method therefor, and automobile

Abstract

An exhaust gas recirculation cooling system (1000) and a control method therefor, and an automobile. The cooling system (1000) comprises an engine (10), a cooler (20), an electronic water pump (30), a water intake pipe (40) and a water discharge pipe (50). The engine (10) comprises a plurality of cylinders (11) and a cylinder cooling water jacket (12), the cooler (20) is used for accommodating a cooling liquid to cool exhaust gas, the electronic water pump (30) is in communication with the cylinder cooling water jacket (12), the water intake pipe (40) is in communication with the cooler (20) and the cylinder cooling water jacket (12), the water discharge pipe (50) is in communication with the cooler (20) and the electronic water pump (30), and the electronic controller (60) is configured to control the flow rate of the electronic water pump (30), such that the cooling liquid circulates in the electronic water pump (30), the cylinder cooling water jacket (12), the water intake pipe (40), the cooler (20) and the water discharge pipe (50).

Description

Exhaust gas recirculation cooling system and control method thereof and vehicle

[0001] This application claims priority to Chinese patent application No. 202311363379.8 filed on October 18, 2023, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of automobile technology, and in particular to an EGR cooling system and a control method thereof, and an automobile. Background Art

[0003] Exhaust Gas Recirculation (EGR) technology, a technology that returns a portion of the engine's exhaust gas to the intake system, where it re-enters the cylinders for combustion along with fresh air. This technology effectively reduces NOx emissions. EGR exhaust gas is hot and must be cooled by an EGR cooler before it can be re-introduced into the cylinders for combustion. However, if the EGR cooler fails to cool the high exhaust gas temperature in a timely manner, the coolant may boil, potentially damaging components. Technical issues

[0004] In view of this, an embodiment of the present application provides an exhaust gas recirculation cooling system, a control method thereof, and a vehicle, which, by adding a means for adjusting the cooler, timely adjusts the coolant flow rate to reduce the occurrence of coolant boiling in the EGR cooler. Technical Solutions

[0005] An embodiment of the present application provides a cooling system for exhaust gas recirculation, comprising: an engine, comprising a plurality of cylinders and a cylinder cooling water jacket, wherein the cylinder cooling water jacket surrounds the cylinders and is used to contain coolant to cool the cylinders; a cooler, used to contain coolant to cool the exhaust gas; an electronic water pump, used to drive the flow of coolant, the electronic water pump being connected to the cylinder cooling water jacket; a water inlet pipe, connecting the cooler and the cylinder cooling water jacket; a water outlet pipe, connecting the cooler and the electronic water pump; and an electronic controller, configured to control the flow rate of the electronic water pump so that the coolant circulates in the electronic water pump, the cylinder cooling water jacket, the water inlet pipe, the cooler and the water outlet pipe.

[0006] In some embodiments, the engine also includes a heat dissipation pipe, which connects the cylinder cooling water jacket and the electronic water pump so that the coolant circulates in the cylinder cooling water jacket, the heat dissipation pipe and the electronic water pump, wherein the coolant flows from the heat dissipation pipe to the electronic water pump.

[0007] In some embodiments, the cylinder cooling water jacket has a water inlet, a first water outlet and a second water outlet, the first water outlet is connected to the heat dissipation pipe, the second water outlet is connected to the water inlet pipe, the water inlet is connected to the electronic water pump, and the water inlet and the second water outlet are both connected around the same cylinder.

[0008] In some embodiments, the cooling system also includes a water inlet flange, the cooler has a water inlet and a water outlet, the water outlet pipe is connected to the water outlet, the water inlet flange is arranged on the water inlet and connected to the water inlet pipe, and the projection of the axis of the water inlet flange on the outer wall of the cooler has a length component.

[0009] In some embodiments, the cooler has an air inlet disposed outside the water inlet, and the axis of the water inlet flange is inclined toward a side away from the air inlet.

[0010] In some embodiments, the water inlet and the water outlet are located on the same side of the cooler.

[0011] In some embodiments, the water outlet is arranged downstream of the water inlet along the exhaust gas flow direction in the cooler.

[0012] In the cooling system provided in the present application, the electronic water pump and the electronic controller increase the adjustment means of the cooler by controlling the coolant flow inside the cooler, timely adjust the coolant flow, and effectively reduce the occurrence of coolant boiling.

[0013] On the other hand, the present application further provides a control method for controlling the cooling system in the above embodiment, the control method comprising:

[0014] The electronic controller obtains the outlet air temperature of the cooler;

[0015] confirming that the outlet air temperature of the cooler is higher than a first preset value;

[0016] Executing a first control strategy includes the electronic controller acquiring the rotational speed of the electronic water pump and state information of the engine, and increasing the flow rate of the electronic water pump based on the rotational speed and the state information.

[0017] confirming that the outlet air temperature of the cooler is lower than a second preset value; and

[0018] executing a second control strategy, including obtaining, by the electronic controller, information about the rotational speed of the electronic water pump and state of the engine, and reducing the flow rate of the electronic water pump based on the rotational speed and the state information;

[0019] The first preset value and the second preset value are respectively the maximum value and the minimum value of the optimal temperature required for the exhaust gas to be cooled and to participate in the exhaust gas recirculation.

[0020] In some embodiments, the control method further includes:

[0021] Confirm that the exhaust gas recirculation function is turned off;

[0022] The rotation speed of the electronic water pump is greater than a third preset value, so that the coolant in the water outlet pipe flows.

[0023] In summary of some embodiments, the control method further includes:

[0024] The electronic controller obtains a real-time EGR rate of exhaust gas recirculation;

[0025] Confirm that the EGR rate is increasing;

[0026] executing the first control strategy;

[0027] confirming that the EGR rate is in a reduced state; and

[0028] The second control strategy is executed.

[0029] The present application also provides a car, which includes the cooling system described in the above embodiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG1 is a schematic structural diagram of a cooling system according to one or more embodiments of the present application, wherein arrows indicate reference flow directions of the coolant;

[0031] FIG2 is a structural isometric view of a cooling system according to one or more embodiments of the present application, wherein arrows indicate reference flow directions of exhaust gas;

[0032] FIG3 is a structural isometric view of the cooling system of FIG2 from another perspective;

[0033] 4 is a cross-sectional view of a partial structure of a cooling system according to one or more embodiments of the present application, wherein arrows indicate reference flow directions of exhaust gas;

[0034] FIG5 is a flow chart of a control method according to one or more embodiments of the present application;

[0035] FIG6 is a flow chart of another control method according to one or more embodiments of the present application.

[0036] Description of Reference Numerals

[0037] Cooling system 1000;

[0038] Engine 10; cylinder 11; cylinder cooling water jacket 12; water inlet 12A; first water outlet 12B; second water outlet 12C; heat dissipation pipe 13;

[0039] Cooler 20; water inlet 20A; water outlet 20B; air inlet 21A;

[0040] Electronic water pump 30; water inlet pipe 40; water outlet pipe 50; electronic controller 60; water inlet flange 70. Modes for Carrying Out the Invention

[0041] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0042] In the description of the embodiments of the present application, it should be noted that the terms "upper," "lower," "front," "rear," "inner," and "outer" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are intended only to facilitate the description of the embodiments of the present application and to simplify the description. They do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the embodiments of the present application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0043] In the description of the embodiments of this application, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of this application based on the specific circumstances.

[0044] In the embodiments of the present application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, a first feature being "above," "above," and "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0045] In the description of this specification, reference to terms such as "some embodiments," "particularly," or "specific example" means that a specific feature, structure, material, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, the exemplary expressions of the above terms do not necessarily refer to the same embodiment.

[0046] In the related art, the exhaust gas recirculation function on the car is to send part of the high-temperature exhaust gas discharged by the engine back into the engine to dilute the oxygen concentration, thereby reducing the maximum combustion temperature and reducing the production of nitrogen oxides. The high-temperature exhaust gas needs to be cooled by the cooler to a certain temperature before it can be sent back to the engine, especially in cars without intercoolers. The heat dissipation core inside the cooler exchanges heat with the high-temperature gas to complete the cooling before the intake. At the same time, the heat dissipation core needs to exchange heat with the coolant in the cooler to reduce its own temperature. The coolant used by the cooler is drawn from the engine's cooling system and circulated through the water pump of the engine's cooling system. The water pump of the engine's cooling system is driven by a belt connected to the engine's input shaft. Due to the limitations of the structural design, the adjustment means of the cooler are very limited. If the cooling is not timely, there will be a risk of the coolant boiling.

[0047] An embodiment of the present application provides an exhaust gas recirculation cooling system 1000. Referring to Figures 1 to 3, the system includes an engine 10, a cooler 20, an electronic water pump 30, a water inlet pipe 40, a water outlet pipe 50, and an electronic controller 60. The engine 10 includes a plurality of cylinders 11 and a cylinder cooling water jacket 12. The cylinder cooling water jacket 12 surrounds the cylinders 11 and is configured to contain coolant for cooling the cylinders 11. The cooler 20 is configured to cool the exhaust gas by passing coolant through the coolant. The electronic water pump 30 is configured to drive the flow of coolant and is connected to the cylinder cooling water jacket 12. The water inlet pipe 40 connects the cooler 20 and the cylinder cooling water jacket 12, and the water outlet pipe 50 connects the cooler 20 and the electronic water pump 30. The electronic controller 60 is configured to control the flow rate of the electronic water pump 30 so that the coolant circulates through the electronic water pump 30, the cylinder cooling water jacket 12, the water inlet pipe 40, the cooler 20, and the water outlet pipe 50.

[0048] Engine 10 includes multiple cylinders 11. In some embodiments, these cylinders 11 are arranged in sequence. Common types include straight-4, V6, or V8 engines. Atomized fuel enters cylinders 11 and burns, driving pistons to rotate the crankshaft and output power. As the combustion reaction occurs, the temperature of cylinders 11 rises dramatically. A cylinder cooling water jacket 12 surrounds the outer wall of cylinder 11. This jacket, formed during the casting and machining process of engine components, is a critical component of the engine's cooling system. It contains a cavity that holds coolant, which circulates within the cavity, driven by the engine's cooling system's water pump, to cool cylinders 11.

[0049] The electronic water pump 30 is a water pump that uses electrical energy as energy to drive the flow of liquid. Centrifugal water pumps are commonly used in automobiles. Its structure includes a transmission component, blades and an outlet valve. In the embodiment of the present application, the transmission component includes a motor for driving the blades to rotate, and the outlet valve can be a solenoid valve to control the outlet flow rate.

[0050] The electronic controller 60 is an information processing device including a programmable controller, a single-chip microcomputer, or an integrated circuit. The electronic controller 60 can be configured through the vehicle's electronic control unit (ECU). The electronic controller 60 is electrically connected to the electronic water pump 30 and sends electrical signals to control the flow rate of the electronic water pump 30. Specific implementation methods include one of the following:

[0051] (1) PWM speed regulation mode, regulating the motor speed;

[0052] (2) switching the main circuit connection mode and adjusting the motor speed;

[0053] (3) Control the opening of the outlet valve to adjust the flow rate.

[0054] The electronic water pump 30 and the electronic controller 60 participate in the composition of the cooling system 1000. By controlling the coolant flow rate inside the cooler 20, the adjustment means of the cooler 20 are increased. A pre-calibrated control scheme can be written into the readable storage medium of the electronic controller 60 to adjust the coolant flow rate in time, effectively reducing the occurrence of coolant boiling.

[0055] In some embodiments, please refer to Figures 1 to 3, the engine 10 also includes a heat dissipation pipe 13, which connects the cylinder cooling water jacket 12 and the electronic water pump 30 to allow the coolant to circulate in the cylinder cooling water jacket 12, the heat dissipation pipe 13 and the electronic water pump 30, wherein the coolant flows from the heat dissipation pipe 13 to the electronic water pump 30.

[0056] The heat dissipation circuit 13 includes a radiator, a heat exchange fan, and a water tank. For example, the radiator is located behind the air intake grille on the front of the car to increase the heat dissipation area of ​​the coolant. The heat exchange fan accelerates heat exchange with the outside cold air to dissipate heat and reduce the coolant temperature.

[0057] The electronic water pump 30 is connected to the heat dissipation pipeline 13 and is also involved in the engine's cooling system, providing power for the flow of coolant. During the startup and operation of the engine, it is first necessary to "warm up" to reach a suitable operating temperature. At this time, the coolant does not flow, or the coolant circulation loop is changed by the thermostat of the engine's cooling system, preventing the engine from cooling down. At this time, the exhaust gas recirculation function is also not enabled. After the engine enters the normal working state, the temperature of the cylinder 11 rises, the electronic water pump 30 starts, and the coolant in the cylinder cooling water jacket 12 begins to circulate. Under certain working conditions, the exhaust gas recirculation function is enabled, and the coolant in the cooling system 1000 also begins to circulate. The electronic water pump 30 also provides power for the coolant circulation in the cooling system 1000, so there can be multiple outlet valves of the electronic water pump 30, which are respectively connected to the water outlet pipe 50 and the heat dissipation pipeline 13.

[0058] During hill climbing or idling conditions, the exhaust gas recirculation function is disabled, but the engine's cooling system remains operational, and the motor of the electronic water pump 30 remains within a certain speed range. This creates negative pressure at the end of the outlet pipe 50 connected to the electronic water pump 30, forcing the coolant in the cooler 20 to flow toward the outlet pipe at a constant flow rate. When the exhaust gas recirculation function is reactivated, the high-temperature gases flowing into the cooler do not immediately cause the coolant temperature to rise sharply, effectively reducing the risk of boiling.

[0059] In some embodiments, referring to Figures 1 to 3 , the cylinder cooling water jacket 12 has a water inlet 12A, a first water outlet 12B, and a second water outlet 12C. The first water outlet 12B is connected to the heat dissipation pipe 13, the second water outlet 12C is connected to the water inlet pipe 40, and the water inlet 12A is connected to the electronic water pump 30. The water inlet 12A and the second water outlet 12C are both connected to the periphery of the same cylinder 11.

[0060] According to the coolant's circulation path and heat exchange process, the coolant has a lower temperature after flowing out of the heat dissipation pipe 13. The water inlet pipe 40 draws water from the second water outlet 12C near the water inlet end 12A of the cylinder cooling water jacket 12 and introduces it into the cooler 20. This can ensure that the coolant has an appropriate temperature before entering the cooler 20 and also facilitate the pipeline layout without designing a lengthy pipeline to draw water from near the heat dissipation pipe 13.

[0061] Referring to Figure 2 , the aforementioned "connected to the periphery of the same cylinder 11" includes the water inlet pipe 40 being connected at the junction of two cylinders 11. Considering each cylinder 11 independently, any complete or partial connection between the second water outlet 12C and the water inlet 12A falls within the aforementioned "connected to the periphery of the same cylinder 11" embodiment. In some embodiments, by providing a manifold, multiple water inlet ends 12A or first water outlet ends 12B are provided, such that at least one water inlet end 12A and the second water outlet end 12C are both connected to the periphery of the same cylinder 11.

[0062] In some embodiments, please refer to Figures 1, 2 and 4, the cooling system 1000 also includes a water inlet flange 70, the cooler 20 has a water inlet 20A and a water outlet 20B, the water outlet pipe 50 is connected to the water outlet 20B, the water inlet flange 70 is arranged on the water inlet 20A and is connected to the water inlet pipe 40, and the projection of the axis of the water inlet flange 70 on the outer wall of the cooler 20 has a length component, that is, the axis of the water inlet flange 70 is not perpendicular to the outer wall surface of the cooler 20.

[0063] The water inlet flange 70 guides the coolant flowing into the cooler 20. The water inlet flange 70 is a flange-shaped component. The cross-section of the cooler 20's outer shell is rectangular. The water inlet flange 70 provides a better seal between the water inlet pipe 40 and the cooler 20 and facilitates assembly. The water inlet flange 70 has a cylindrical cavity inside, connecting to the water inlet 20A. The projection of the axis of the water inlet flange 70 on the outer wall of the cooler 20 has a length component, meaning that the water inlet flange 70 is tilted on the outer wall of the cooler 20. This helps reduce the splashing phenomenon caused by the coolant flowing into the cooler 20 and striking the heat sink or inner wall. This splashing phenomenon reduces the flow rate of the coolant and affects the cooling effect, especially when the coolant is injected perpendicular to the inner wall. Therefore, the water inlet flange 70 is tilted.

[0064] In some embodiments, the cooler 20 has an air inlet 21A positioned outside the water inlet 20A, and the axis of the water inlet flange 70 is tilted away from the air inlet 21A. When high-temperature gas flows into the cooler 20, the temperature of the air inlet 21A rises rapidly. The water inlet flange 70 directs the coolant and directly pours it near the air inlet 21A, where the coolant flows in a circuitous manner, ensuring a cooling effect at the air inlet 21A.

[0065] 2 , the water inlet 20A and the water outlet 20B are located on the same side of the cooler 20. This facilitates the arrangement of the cooling system 1000 in a vehicle.

[0066] In some embodiments, referring to FIG2 , water outlet 20B is positioned downstream of water inlet 20A along the direction of exhaust gas flow within cooler 20. For ease of understanding, the high-temperature exhaust gas is considered a hot stream, and the coolant is considered a cold stream. In this embodiment, the high-temperature exhaust gas and the coolant flow in the same direction, i.e., the hot and cold streams are arranged in parallel, enabling heat exchange and having the advantage of easing the heat resistance requirements of the cooler 20 wall material.

[0067] The present application also provides a control method for a cooling system. In some embodiments, please refer to FIG5 . The control method includes the following steps:

[0068] S100, the electronic controller obtains the outlet air temperature of the cooler;

[0069] S111, confirming that the outlet temperature of the cooler is higher than a first preset value;

[0070] S112, executing a first control strategy, including the electronic controller acquiring the speed of the electronic water pump and the state information of the engine, and increasing the flow rate of the electronic water pump based on the speed and the state information;

[0071] S121, confirming that the outlet temperature of the cooler is lower than a second preset value;

[0072] S122 , executing a second control strategy, including the electronic controller acquiring the rotational speed of the electronic water pump and the state information of the engine, and reducing the flow rate of the electronic water pump based on the rotational speed and the state information.

[0073] The first and second preset values ​​are the maximum and minimum values, respectively, for the optimal exhaust gas temperatures required for exhaust gas recirculation after cooling. It should be noted that these optimal temperatures refer to optimal exhaust gas temperatures after cooling, not extremes, intended to prevent abnormalities caused by extreme exhaust gas temperatures.

[0074] A temperature sensor can be set at the air outlet of the cooler 20 to detect the outlet temperature. When it is higher than the first preset value, it is the maximum value of the optimal temperature of the gas discharged from the cooler 20 and flows back into the engine 10. In order to make the exhaust gas recirculation function work effectively, it is necessary to timely reduce the exhaust gas temperature to meet the requirements. Therefore, the first control strategy is executed to increase the flow rate of the electronic water pump 30. The specific implementation method needs to be selected based on the speed of the electronic water pump 30 and the status information of the engine 10 obtained by the electronic controller 60.

[0075] In some embodiments, if the temperature of the engine 10 is normal, the fuel consumption is high, and the speed of the electronic water pump 30 is normal, it is preferred to increase the opening of the outlet valve of the electronic water pump 30 to increase the flow rate of the electronic water pump 30, thereby effectively reducing the problem of excessive energy consumption of the entire vehicle.

[0076] In some embodiments, if the temperature of the engine 10 is normal, the fuel consumption is normal, and the speed of the electronic water pump 30 is high, it is preferred to increase the opening of the outlet valve of the electronic water pump 30 and reduce the speed of the motor of the electronic water pump 30 to increase the flow rate of the electronic water pump 30.

[0077] In some embodiments, the temperature of the engine 10 is relatively high, the fuel consumption is normal, the speed of the electronic water pump 30 is normal, and the electronic water pump 30 is connected to the heat dissipation pipe 13 and also provides power for the cooling system of the engine 10, then the speed of the motor of the electronic water pump 30 is increased first to increase the flow rate of the electronic water pump 30, which is beneficial to accelerate the cooling of the cooler 20 and the cooling of the engine 10 at the same time.

[0078] The above-mentioned "high" and "normal" are based on the optimal operating state of the vehicle. There can be multiple optimal operating states, corresponding to conditions such as acceleration, idling, climbing, or carrying a load. The optimal state information of the engine 10 and the optimal speed of the electronic water pump 30 under these optimal operating states can be determined through testing. This information can be interrelated, meaning that different optimal states will produce different information. The information processing method is written to the readable storage medium of the electronic controller 60. The electronic controller 60 then comprehensively determines which implementation method to use to execute the first control strategy based on the current information.

[0079] The same applies to the aforementioned execution of the second control strategy. A temperature sensor can be provided at the outlet of the cooler 20 to detect the outlet temperature. When the outlet temperature exceeds the second preset value, which represents the minimum temperature of the gas discharged from the cooler 20 and serves to reduce nitrogen oxide production within the engine 10, the second control strategy is executed to reduce the flow rate of the electronic water pump 30. The specific implementation method is selected based on the speed of the electronic water pump 30 and the status information of the engine 10 obtained by the electronic controller 60.

[0080] In some embodiments, the control method further includes:

[0081] S201, confirming that the exhaust gas recirculation function is in the off state;

[0082] S202: The rotation speed of the electronic water pump is greater than a third preset value, so that the coolant in the water outlet pipe flows.

[0083] The water outlet pipe 50 is connected to the electronic water pump 30. The rotation of the electronic water pump 30 creates negative pressure at the connection point, maintaining coolant flow. When the exhaust gas recirculation function is suddenly activated, high-temperature gases flow into the cooler 20 without immediately causing a sharp rise in the coolant temperature, thereby effectively reducing the risk of boiling. Bench calibration testing, the process of pre-shipment tuning of a vehicle or engine, determines the optimal third preset speed for the electronic water pump 30. This ensures sufficient coolant flow within the cooler 20 without excessively high vehicle energy consumption.

[0084] In some embodiments, the electronic water pump 30 is connected to the heat dissipation pipe 13 and also provides power for the cooling system of the engine 10. When the exhaust gas recirculation function is turned off and the cooling system of the engine 10 is in working condition, the electronic water pump 30 still remains in a certain speed range, which can play a role in making the coolant in the cooler 20 flow. There is no need to arrange a separate electronic water pump, which reduces costs and saves space in the vehicle.

[0085] In some embodiments, referring to FIG6 , the control method further includes the steps of:

[0086] S300, the electronic controller obtains a real-time EGR rate of exhaust gas recirculation;

[0087] S311, confirming that the EGR rate is in an increasing state;

[0088] S312, executing the first control strategy;

[0089] S321, confirming that the EGR rate is in a decreasing state;

[0090] S322: Execute the second control strategy.

[0091] The EGR rate, also known as the exhaust gas recirculation rate, refers to the amount of exhaust gas introduced into the engine. It can be calculated as: EGR rate = Intaken exhaust gas volume / (Intake air volume + Intaken exhaust gas volume) * 100%. As you can see, increasing the EGR rate increases the load on the cooler, resulting in higher temperatures at the air intake port 21A. Decreasing the EGR rate reduces the load on the cooler, resulting in lower temperatures at the air intake port 21A.

[0092] An oxygen sensor or a carbon dioxide sensor can be arranged to sense the current combustion conditions in the engine 10 and feed the information back to the electronic controller 60. The electronic controller 60 calculates and determines the changing trend of the EGR rate at this time, and executes the corresponding first control strategy or the second control strategy. It can be understood that more specific triggering conditions need to be adjusted according to different design requirements and the characteristics of the product itself. For example, the EGR rate is 10% and shows a sharp increase trend. When it reaches 12%, the first control strategy is executed to cool the newly flowing exhaust gas in time.

[0093] On the other hand, the present application also provides a car, which includes the above-mentioned cooling system 1000, and its exhaust gas recirculation function is effective and can effectively reduce the pollution of automobile exhaust to the environment.

[0094] The various embodiments / implementations provided in this application can be combined with each other without causing any contradiction.

[0095] The above description is merely an optional embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A cooling system for exhaust gas recirculation, wherein: The exhaust gas recirculation cooling system comprises: An engine, comprising a plurality of cylinders and a cylinder cooling water jacket, wherein the cylinder cooling water jacket surrounds the cylinders and is used to contain a coolant to cool the cylinders; a cooler for containing a coolant to cool the exhaust gases; An electronic water pump, used for driving the coolant to flow, the electronic water pump being connected to the cylinder cooling water jacket; A water inlet pipe, communicating the cooler and the cylinder cooling water jacket; a water outlet pipe, connecting the cooler and the electronic water pump; and The electronic controller is configured to control the flow rate of the electronic water pump so that the coolant circulates in the electronic water pump, the cylinder cooling water jacket, the water inlet pipe, the cooler and the water outlet pipe.

2. The cooling system according to claim 1, wherein: The engine also includes a heat dissipation pipeline, which is connected to the cylinder cooling water jacket and the electronic water pump so that the coolant circulates in the cylinder cooling water jacket, the heat dissipation pipeline and the electronic water pump, wherein the coolant flows from the heat dissipation pipeline to the electronic water pump.

3. The cooling system according to claim 2, wherein: The cylinder cooling water jacket has a water inlet, a first water outlet and a second water outlet. The first water outlet is connected to the heat dissipation pipeline, the second water outlet is connected to the water inlet pipe, the water inlet is connected to the electronic water pump, and the water inlet and the second water outlet are both connected around the same cylinder.

4. The cooling system according to claim 1, wherein: The cooling system also includes a water inlet flange, the cooler has a water inlet and a water outlet, the water outlet pipe is connected to the water outlet, the water inlet flange is arranged on the water inlet and connected to the water inlet pipe, and the projection of the axis of the water inlet flange on the outer wall of the cooler has a length component.

5. The cooling system according to claim 4, wherein: The cooler has an air inlet, which is arranged on the outside of the water inlet, and the axis of the water inlet flange is inclined to a side away from the air inlet.

6. The cooling system according to claim 4, wherein: The water inlet and the water outlet are located on the same side of the cooler; and / or, The water outlet is arranged downstream of the water inlet along the exhaust gas flow direction in the cooler.

7. A control method, wherein: The control method is used to control the cooling system according to any one of claims 1 to 6, and the control method comprises: The electronic controller obtains the outlet air temperature of the cooler; confirming that the outlet air temperature of the cooler is higher than a first preset value; Executing a first control strategy, including the electronic controller acquiring the rotation speed of the electronic water pump and the state information of the engine, and increasing the flow rate of the electronic water pump based on the rotation speed and the state information; confirming that the outlet air temperature of the cooler is lower than a second preset value; and Executing a second control strategy, including the electronic controller acquiring the rotation speed of the electronic water pump and the state information of the engine, and reducing the flow rate of the electronic water pump based on the rotation speed and the state information; The first preset value and the second preset value are respectively the maximum value and the minimum value of the optimal temperature required for the exhaust gas to be cooled to participate in the exhaust gas recirculation.

8. The control method according to claim 7, wherein: The control method further comprises: Confirm that the exhaust gas recirculation function is turned off; The rotation speed of the electronic water pump is greater than a third preset value so that the coolant in the water outlet pipe flows.

9. The control method according to claim 7, wherein: The control method further comprises: The electronic controller obtains a real-time EGR rate of exhaust gas recirculation; Confirm that the EGR rate is in the increasing state; executing the first control strategy; confirming that the EGR rate is in a reduced state; and The second control strategy is executed.

10. A car, wherein: The vehicle comprises the cooling system according to any one of claims 1 to 6.

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