Engine emission system, thermal management control method thereof and vehicle

Abstract

The invention provides an engine emission system, a thermal management control method thereof and a vehicle, and solves the technical problem of high oil consumption caused by high oil injection quantity in an engine thermal management mode in the prior art. According to the engine exhaust system provided by the invention, the recirculation control valve, the recirculation bypass control valve, the exhaust throttle valve and the air inlet throttle valve are arranged, and according to the temperature of the cooling liquid of the engine and the temperature of the waste gas at the air inlet of the post-treatment system, the exhaust gas at the air inlet of the post-treatment system is exhausted; according to the method, a recirculation control valve, a recirculation bypass control valve, an air inlet throttling valve and an exhaust throttling valve are controlled to be switched on or switched off, so that work of an aftertreatment system and / or work of an exhaust gas recirculation cooling system are / is controlled, and the temperature of recirculated exhaust gas entering an engine fuel system is regulated and controlled; therefore, optimization of waste gas temperature increase and fuel consumption increase is achieved by using corresponding heat management modes under different conditions.

Description

Technical Field

[0001] This application relates to the technical field of automotive exhaust emissions, and particularly to an engine emission system, its thermal management control method, and a vehicle. Background Art

[0002] Automobile exhaust is the waste gas generated when an automobile is in use, containing hundreds of different compounds, and the pollutants therein include solid suspended particles, carbon monoxide, carbon dioxide, hydrocarbons, nitrogen oxides, lead, sulfur oxides, etc. Therefore, the exhaust gas generated by an automobile engine often needs to be treated during emission.

[0003] When the temperature at the inlet of the engine emission after-treatment device is low, the engine emission after-treatment device cannot effectively convert harmful pollutants, resulting in the engine and the vehicle's emissions exceeding the standard. Therefore, in the engine thermal management mode, when the temperature at the inlet of the engine emission after-treatment device does not meet the minimum temperature requirement, more fuel is injected into the engine to quickly raise the temperature of the after-treatment device to the operating temperature at which it can effectively convert harmful pollutants, reducing pollutant emissions. However, in the engine thermal management mode, the large fuel injection volume leads to the disadvantage of high fuel consumption. Summary of the Invention

[0004] In view of this, this application provides an engine emission system and its thermal management control method. The engine emission system provided by this application realizes the optimization of exhaust gas temperature increase and fuel consumption increase by setting the coordinated operation of the recirculation control valve, the recirculation bypass control valve, the exhaust throttle valve, and the intake throttle valve under different conditions.

[0005] To achieve the above object, this application provides an engine emission system, including: An engine fuel system; An exhaust gas recirculation cooling system, which includes an exhaust gas recirculation cooler, a recirculation control valve, and a supercharger. The intake port of the recirculation control valve is connected to the exhaust manifold of the engine, the outlet port of the recirculation control valve is connected to the intake port of the exhaust gas recirculation cooler, and the intake port of the supercharger is connected to the exhaust manifold of the engine; A thermal management system, which includes an intake throttle valve, an exhaust throttle valve, and a recirculation bypass control valve. The intake port of the recirculation bypass control valve is connected to the exhaust manifold of the engine, the outlet port of the recirculation bypass control valve is connected to the intake manifold of the engine and the outlet port of the exhaust gas recirculation cooler, the outlet port of the intake throttle valve is connected to the intake manifold of the engine, and the intake port of the exhaust throttle valve is connected to the outlet port of the supercharger; and; A post-treatment system, the intake port of the post-treatment system is communicated with the outlet port of the exhaust throttle valve, and the post-treatment system is used for treating the exhaust gas discharged from the engine fuel system.

[0006] In an embodiment of the present application, the post-treatment system includes: An oxidation catalytic converter, which is used for converting HC and CO in the exhaust gas and converting NO into NO2; A catalytic conversion device, which is used for catalytically converting nitrogen oxides in the exhaust gas; A particulate matter trap, which is used for trapping carbon particles in the exhaust gas.

[0007] In an embodiment of the present application, the catalytic conversion device includes: A close-coupled selective catalytic reduction device, the intake port of the close-coupled selective catalytic reduction device is communicated with the outlet port of the exhaust throttle valve, and the exhaust port of the close-coupled selective catalytic reduction device is communicated with the intake port of the oxidation catalytic converter; and; A selective catalytic reduction device, the intake port of the selective catalytic reduction device is communicated with the outlet port of the particulate matter trap.

[0008] In an embodiment of the present application, the post-treatment system further includes: A plurality of temperature sensors, which are used for detecting the temperature of the exhaust gas at different stages.

[0009] In an embodiment of the present application, the exhaust gas recirculation cooling system further includes: A flow sensor, which is arranged downstream of the intake throttle valve, and the flow sensor is used for detecting the recirculation gas flow of the recirculation gas after the intake throttle valve, An intake air temperature sensor, which is arranged downstream of the intake throttle valve and is used for detecting the temperature of the recirculation gas entering the intake air system of the engine; An intake air pressure sensor, which is arranged downstream of the intake throttle valve and is used for detecting the pressure of the recirculation gas entering the intake air system of the engine.

[0010] As a second aspect of the present application, the present application further provides a thermal management control method for an engine emission system, the thermal management control method is used for controlling the above-mentioned engine emission system, wherein, the thermal management control method includes: Obtain the temperature of the coolant of the engine; Obtain the exhaust gas temperature at the intake port of the post-treatment system; Control the opening or closing of the recirculation control valve, the recirculation bypass control valve, the intake throttle valve, and the exhaust throttle valve according to the temperature of the coolant and the temperature of the exhaust gas at the intake port of the aftertreatment system, so as to control the operation of the aftertreatment system and / or the operation of the exhaust gas recirculation cooling system.

[0011] In an embodiment of the present application, the controlling the opening or closing of the recirculation control valve, the recirculation bypass control valve, the intake throttle valve, and the exhaust throttle valve according to the temperature of the coolant and the temperature of the exhaust gas at the intake port of the aftertreatment system includes: When the temperature of the exhaust gas at the intake port of the aftertreatment system is greater than or equal to the third preset temperature, control the intake throttle valve, the exhaust throttle valve, and the recirculation bypass control valve to be all closed, and control the recirculation control valve to be opened, and the opening degree of the recirculation control valve is the preset opening degree; or; When the temperature of the exhaust gas at the intake port of the aftertreatment system is less than the third preset temperature, control the opening or closing of the recirculation control valve and the recirculation bypass control valve according to the temperature of the coolant and the temperature of the exhaust gas at the intake port of the aftertreatment system; and determine the opening degrees of the intake throttle valve and the exhaust throttle valve according to the preset engine speed and the preset torque, and control the intake throttle valve to be opened according to the opening degree of the intake throttle valve, and control the exhaust throttle valve to be opened according to the opening degree of the exhaust throttle valve.

[0012] In an embodiment of the present application, the controlling the opening or closing of the recirculation control valve, the recirculation bypass control valve according to the temperature of the coolant and the temperature of the exhaust gas at the intake port of the aftertreatment system includes: When the temperature of the coolant is less than or equal to the first preset temperature, control the recirculation control valve to be closed and control the recirculation bypass control valve to be opened; or; When the temperature of the coolant is greater than the first preset temperature, and the temperature of the exhaust gas at the intake port of the aftertreatment system continuously remains lower than the second preset temperature, and the continuous duration is greater than the first preset duration, control the recirculation bypass control valve to be opened and control the recirculation control valve to be closed; or; When the temperature of the coolant is greater than the first preset temperature, and the temperature of the exhaust gas at the intake port of the aftertreatment system continuously remains lower than the second preset temperature, and the continuous duration is less than or equal to the first preset duration, control the recirculation bypass control valve to be closed and control the recirculation control valve to be opened, and the opening degree of the recirculation control valve is the preset opening degree.

[0013] In an embodiment of the present application, the post-treatment system includes: an oxidation catalytic converter for converting nitrogen oxides in the exhaust gas into nitrogen and water; a close-coupled selective catalytic reduction device, an inlet of the close-coupled selective catalytic reduction device is communicated with an outlet of the exhaust throttle valve, an outlet of the close-coupled selective catalytic reduction device is communicated with an inlet of the oxidation catalytic converter, a selective catalytic reduction device, an inlet of the selective catalytic reduction device is communicated with an outlet of the particulate trap; a particulate trap for trapping carbon particles in the exhaust gas; Wherein, the thermal management control method further includes: Query a corresponding first set conversion rate in a preset database according to the exhaust gas flow rate and the first exhaust gas temperature at the inlet of the close-coupled selective catalytic reduction device; Calculate a first feedforward urea injection amount according to the first nitrogen oxide content in the exhaust gas at the inlet of the close-coupled selective catalytic reduction device and the first set conversion rate; Calculate the actual conversion rate of the close-coupled selective catalytic reduction device according to the first nitrogen oxide content in the exhaust gas at the inlet of the close-coupled selective catalytic reduction device and the second nitrogen oxide content in the exhaust gas at the inlet of the selective catalytic reduction device; Calculate a first corrected urea injection amount according to the actual conversion rate and the first set conversion rate; Calculate the total urea injection amount of the close-coupled selective catalytic reduction device according to the first feedforward urea injection amount and the first corrected urea injection amount, and control the operation of the close-coupled selective catalytic reduction device with the total urea injection amount.

[0014] As a third aspect of the present application, the present application further provides a vehicle, including: The above-mentioned engine emission system; A thermal management controller for executing the above-mentioned thermal management control method.

[0015] The engine emission system provided by the present application controls the recirculation control valve, the recirculation bypass control valve, the exhaust throttle valve, and the intake throttle valve, and controls the opening or closing of the recirculation control valve, the recirculation bypass control valve, the intake throttle valve, and the exhaust throttle valve according to the coolant temperature of the engine and the exhaust gas temperature at the intake port of the aftertreatment system, so as to control the operation of the aftertreatment system and / or the operation of the exhaust gas recirculation cooling system, thereby regulating the exhaust gas discharged from the engine fuel system to pass through the exhaust gas aftertreatment and / or the exhaust gas recirculation to achieve thermal management. When the exhaust gas recirculation is used to achieve thermal management, the opening or closing of the recirculation control valve and the recirculation bypass control valve can also be regulated to determine whether the exhaust gas passes through the EGR cooler for cooling during the exhaust gas recirculation, so as to regulate the temperature of the recirculated exhaust gas entering the engine fuel system, thereby realizing the optimization of the exhaust gas temperature increase and fuel consumption increase by using the corresponding thermal management method under different conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0017] Figure 1 FIG. is a schematic structural diagram of an engine emission system provided by an embodiment of the present application.

[0018] Figure 2 FIG. shows a schematic flow chart of a thermal management control method for an engine emission system provided by an embodiment of the present application.

[0019] Figure 3 FIG. shows a schematic flow chart of a thermal management control method for an engine emission system provided by another embodiment of the present application.

[0020] Figure 4 FIG. shows a schematic flow chart of a thermal management control method for an engine emission system provided by another second embodiment of the present application.

[0021] Figure 5 FIG. shows a diagram of the action area of the recirculation bypass control valve provided by an embodiment of the present application.

[0022] Figure 6 FIG. shows a diagram of the action area of the intake throttle valve and the exhaust throttle valve provided by an embodiment of the present application.

[0023] Figure 7 FIG. shows a schematic flow chart of a thermal management control method for an engine emission system provided by another third embodiment of the present application. Detailed implementation manners

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the protection scope of the present application.

[0025] For the convenience of description, some nouns or terms involved in the embodiments of the present invention are described as follows: DPF: Diesel Particulate Filter, used to trap particulate matter in the exhaust gas. When the mass of the trapped particulate matter reaches a certain level, passive regeneration or active regeneration is required to restore the particulate matter trapping ability of the DPF.

[0026] SCR: Selectively Catalytic Reduction, urea is injected before the SCR to reduce nitrogen oxides in the exhaust gas emissions.

[0027] DOC: Diesel Oxide Catalyst, installed before the DPF, used to convert HC, CO, etc. in the exhaust gas, convert NO in the exhaust gas to NO2, and at the same time increase the exhaust gas temperature to assist the normal operation of the DPF and SCR.

[0028] ccSCR: Close-coupled Selectively Catalytic Reduction device, that is, close-coupled SCR.

[0029] ASC: Ammonia Slip Catalyst, used to oxidize excess ammonia.

[0030] PFM sensor: The flow sensor (Pulse Frequency Modulation Sensor) is a sensor based on pulse frequency modulation technology and can measure the air intake based on the Venturi principle.

[0031] EGR cooler: Exhaust Gas Recirculation Valve cooler, a key component for controlling the exhaust gas recirculation amount, mainly used to reduce nitrogen oxide (NOx) emissions.

[0032] PM sensor: Particulate Matter Sensor, which is used to detect the particulate matter mass after the DPF. The particulate matter mass can be used to diagnose whether the DPF fails and whether the particulate matter exceeds the standard.

[0033] CAC: Charge Air Cooler cools the high-temperature and high-pressure air after supercharging through heat exchange. As the first aspect of this application, this application provides an engine emission system. Figure 1 The following is a schematic structural diagram of an engine emission system provided by an embodiment of this application. As Figure 1 shown, an engine emission system includes: Engine fuel system; the engine fuel system includes an engine, an oil pump, a leak-free injector, and a pressure regulator. The fuel system adopts an electronically controlled high-pressure common rail system with a rail pressure control of 2500 bar to achieve precise fuel control and combustion control. The engine fuel system performs closed-loop control of the oil pump and the pressure regulator with a rail pressure set value, and controls the engine combustion through injection advance angle, etc. Exhaust gas recirculation cooling system, the exhaust gas recirculation cooling system includes an exhaust gas recirculation cooler (EGR cooler), a recirculation control valve, and a supercharger. The intake port of the recirculation control valve is connected to the exhaust manifold of the engine, the outlet port of the recirculation control valve is connected to the intake port of the EGR cooler, and the intake port of the supercharger is connected to the exhaust manifold of the engine; wherein, the recirculation control valve is used to control the exhaust gas flow rate (i.e., EGR flow rate) entering the engine intake system in the exhaust gas generated by the engine fuel system. The EGR cooler is used to cool the high-temperature exhaust gas output by the engine fuel system and increase the exhaust gas flow rate (i.e., EGR flow rate) entering the engine intake system.

[0034] Thermal management system, the thermal management system includes an intake throttle valve, an exhaust throttle valve, and a recirculation bypass control valve. The intake port of the recirculation bypass control valve is connected to the exhaust manifold of the engine, the outlet port of the recirculation bypass control valve is connected to the intake manifold of the engine and the outlet port of the EGR cooler, the outlet port of the intake throttle valve is connected to the intake manifold of the engine, and the intake port of the exhaust throttle valve is connected to the outlet port of the supercharger; wherein, the intake throttle valve is used to reduce the intake air volume and increase the exhaust gas temperature by throttling the intake air. The exhaust throttle valve increases the exhaust back pressure, increases the pumping loss, and increases the exhaust gas temperature. By regulating the recirculation bypass control valve, the intake air temperature of the cold cycle can be increased without using the EGR cooler, and the exhaust gas temperature can be increased. The thermal management system mainly achieves the optimization of temperature increase and fuel consumption increase according to the thermal management method.

[0035] After-treatment system, the intake port of the after-treatment system is connected to the outlet port of the exhaust throttle valve, and the after-treatment system is used to treat the exhaust gas discharged from the engine fuel system.

[0036] Optionally, the exhaust gas recirculation cooling system further includes a turbocharger, which has an electronically controlled wastegate valve. The electronically controlled wastegate valve is used to control the over-speed of the turbocharger caused by excessive intake air pressure under high load, so that part of the exhaust gas is discharged into the exhaust pipe without passing through the turbocharger.

[0037] The engine emission system provided by the present application controls the on or off of the recirculation control valve, the recirculation bypass control valve, the intake throttle valve, and the exhaust throttle valve by setting the recirculation control valve, the recirculation bypass control valve, the exhaust throttle valve, and the intake throttle valve, and according to the coolant temperature of the engine and the exhaust gas temperature at the intake port of the aftertreatment system, so as to control the operation of the aftertreatment system and / or the operation of the exhaust gas recirculation cooling system, and then the exhaust gas discharged from the engine fuel system can be thermally managed through exhaust gas aftertreatment and / or exhaust gas recirculation. When the exhaust gas recirculation is used for thermal management, the on or off of the recirculation control valve and the recirculation bypass control valve can also be adjusted to realize whether the exhaust gas passes through the EGR cooler for cooling during exhaust gas recirculation, so as to control the temperature of the recirculated exhaust gas entering the engine fuel system, thereby realizing the optimization of exhaust gas temperature increase and fuel consumption increase by using corresponding thermal management methods under different conditions.

[0038] In an embodiment of the present application, as Figure 1 shown, the aftertreatment system includes: an oxidation catalytic converter DOC, which is used to convert HC, CO, etc. in the exhaust gas and convert NO into NO2; a catalytic conversion device, which is used to catalytically convert nitrogen oxides in the exhaust gas; a particulate matter trap DPF, which is used to trap carbon particles in the exhaust gas.

[0039] Specifically, the catalytic conversion device includes: a close-coupled selective catalytic reduction device CCSCR and a selective catalytic reduction device SCR. Among them, the intake port of the close-coupled selective catalytic reduction device CCSCR is connected to the outlet of the exhaust throttle valve, and the exhaust port of the close-coupled selective catalytic reduction device CCSCR is connected to the intake port of the oxidation catalytic converter DOC; the outlet of the oxidation catalytic converter DOC is connected to the intake port of the particulate matter trap DPF; the intake port of the selective catalytic reduction device SCR is connected to the outlet of the particulate matter trap DPF. The outlet of the selective catalytic reduction device SCR is connected to the intake port of a particulate matter sensor (i.e., a PM sensor). The PM sensor is used to measure the particulate matter mass after passing through the particulate matter trap DPF and is used to diagnose whether the DPF fails and whether the particulate matter exceeds the standard.

[0040] Specifically, the aftertreatment system further includes a plurality of temperature sensors, which are used to detect the temperature at each stage of the exhaust gas. For example, as Figure 1As shown, the aftertreatment system includes a fourth temperature sensor T4 for detecting the temperature of the exhaust gas downstream of the exhaust throttle valve (i.e., the inlet of the close-coupled selective catalytic reduction device CCSCR); a fifth temperature sensor T5 for detecting the temperature of the exhaust gas at the outlet of the close-coupled selective catalytic reduction device CCSCR (i.e., the inlet of the diesel oxidation catalyst DOC); a seventh temperature sensor T7 for detecting the temperature of the exhaust gas at the outlet of the diesel particulate filter DPF (i.e., the inlet of the selective catalytic reduction device SCR); and an eighth temperature sensor T8 for detecting the temperature of the exhaust gas at the outlet of the selective catalytic reduction device SCR.

[0041] Specifically, the aftertreatment system further includes a plurality of nitrogen oxide sensors for detecting the content of nitrogen oxides in the exhaust gas. For example, Figure 1 As shown, the aftertreatment system includes a first nitrogen oxide sensor NO x 1 for detecting the content of nitrogen oxides in the exhaust gas to be measured at the inlet of the close-coupled selective catalytic reduction device CCSCR; and a second nitrogen oxide sensor NO x 2 for detecting the content of nitrogen oxides in the exhaust gas at the outlet of the diesel particulate filter DPF.

[0042] In this application, by setting up two-stage SCR for treating NOx emissions and suppressing the generation of N2O, the content of nitrogen oxides in the exhaust gas is further reduced.

[0043] In an embodiment of this application, as Figure 1 shown, the exhaust gas recirculation cooling system further includes: A flow sensor (i.e., a PFM sensor), which is arranged downstream of the intake throttle valve and is used to detect the flow rate of the recirculated gas after the intake throttle valve. An intake air temperature sensor T2, which is arranged downstream of the intake throttle valve and is used to detect the temperature of the recirculated gas entering the intake system of the engine. An intake air pressure sensor P2, which is arranged downstream of the intake throttle valve and is used to detect the pressure of the recirculated gas entering the intake system of the engine.

[0044] In an embodiment of this application, as Figure 1 shown, the engine emission system further includes: an air purifier for purifying the air entering the exhaust gas recirculation cooling system; a CAC (charge air cooler) for cooling the high-temperature and high-pressure air after supercharging through heat exchange; and a PFM sensor that can measure the air intake based on the Venturi principle.

[0045] As a second aspect of this application, this application also provides a thermal management control method for an engine emission system, which is used to control the above-mentioned engine emission system.Figure 2 As shown in the figure, it is a schematic flowchart of a thermal management control method for an engine emission system provided by an embodiment of the present application. As Figure 2 shown, the thermal management control method for the engine emission system specifically includes the following steps: S1: Obtain the temperature of the coolant of the engine; When the vehicle is cold-started, obtain the temperature of the coolant of the engine, and the temperature of the coolant can be detected by a temperature sensor.

[0046] S2: Obtain the temperature of the exhaust gas at the intake port of the aftertreatment system; Specifically, the temperature of the exhaust gas at the intake port of the aftertreatment system can be detected by a temperature sensor arranged at the intake port position of the aftertreatment system.

[0047] S3: According to the temperature of the coolant and the temperature of the exhaust gas at the intake port of the aftertreatment system, control the opening or closing of the recirculation control valve, the recirculation bypass control valve, the intake throttle valve, and the exhaust throttle valve to control the operation of the aftertreatment system and / or the operation of the exhaust gas recirculation cooling system.

[0048] According to the temperature of the coolant and the temperature of the exhaust gas at the intake port of the aftertreatment system, control the opening or closing of the recirculation control valve, the recirculation bypass control valve, the intake throttle valve, and the exhaust throttle valve to control the operation of the aftertreatment system and / or the operation of the exhaust gas recirculation cooling system.

[0049] A thermal management control method for an engine emission system provided by the present application controls the opening or closing of the recirculation control valve, the recirculation bypass control valve, the intake throttle valve, and the exhaust throttle valve according to the temperature of the coolant of the engine and the temperature of the exhaust gas at the intake port of the aftertreatment system to control the operation of the aftertreatment system and / or the operation of the exhaust gas recirculation cooling system, so as to regulate that the exhaust gas discharged from the engine fuel system can pass through the exhaust gas aftertreatment and / or the exhaust gas recirculation to achieve thermal management. When the exhaust gas recirculation is used to achieve thermal management, the opening or closing of the recirculation control valve and the recirculation bypass control valve can also be regulated to determine whether the exhaust gas passes through the EGR cooler for cooling during the exhaust gas recirculation, so as to regulate the temperature of the recirculated exhaust gas entering the engine fuel system, thereby achieving the optimization of exhaust gas temperature increase and fuel consumption increase by using corresponding thermal management methods under different conditions.

[0050] In an embodiment of the present application, as Figure 3 shown, S3 (according to the temperature of the coolant and the temperature of the exhaust gas at the intake port of the aftertreatment system, control the opening or closing of the recirculation control valve, the recirculation bypass control valve, the intake throttle valve, and the exhaust throttle valve to control the operation of the aftertreatment system and / or the operation of the exhaust gas recirculation cooling system) specifically includes the following steps: S30: Determine whether the exhaust gas temperature at the intake port of the aftertreatment system is less than the third preset temperature T3; Specifically, the third preset temperature T3 is 220 - 280 °C. Optionally, the third preset temperature is 250 °C.

[0051] When the judgment result of S30 is yes, that is, the exhaust gas temperature at the intake port of the aftertreatment system is less than the third preset temperature T3, it indicates that the exhaust gas temperature of the exhaust gas discharged from the engine fuel system is relatively low. Then, during the exhaust gas recirculation, it is necessary to determine the opening or closing of the recirculation control valve and the recirculation bypass control valve again according to the coolant temperature and the exhaust gas temperature at the intake port of the aftertreatment system, so as to determine whether the recirculated gas needs to be cooled by the EGR cooler, that is, execute S31 - S32. For example, if EGR cooling is required, then control the recirculation bypass control valve to open and the recirculation control valve to close, so that the exhaust gas discharged from the engine fuel system does not need to be cooled by the EGR cooler when circulating.

[0052] When the judgment result of S30 is no, that is, the exhaust gas temperature at the intake port of the aftertreatment system is greater than or equal to the third preset temperature T3, it indicates that the exhaust gas temperature of the exhaust gas discharged from the engine fuel system is relatively high. Then, during the exhaust gas recirculation, since the exhaust gas temperature is too high, execute exhaust gas cooling and then recirculate. In addition, the aftertreatment system is closed and does not perform heat treatment on the exhaust gas, that is, execute S33.

[0053] S31: Control the opening or closing of the recirculation control valve and the recirculation bypass control valve according to the coolant temperature and the exhaust gas temperature at the intake port of the aftertreatment system; Specifically, when the judgment result of S30 is yes, that is, the exhaust gas temperature at the intake port of the aftertreatment system is less than the third preset temperature T3, it indicates that the exhaust gas temperature of the exhaust gas discharged from the engine fuel system is relatively low. At this time, it is necessary to determine whether to turn on the cooling function according to the coolant temperature and the exhaust gas temperature at the intake port of the aftertreatment system, that is, whether the exhaust gas needs to be cooled by the EGR cooler.

[0054] S32: Determine the opening degrees of the intake throttle valve and the exhaust throttle valve according to the preset engine speed and the preset engine torque, and control the intake throttle valve to open according to the opening degree of the intake throttle valve, and control the exhaust throttle valve to open according to the opening degree of the exhaust throttle valve.

[0055] When the exhaust gas temperature at the intake port of the aftertreatment system is less than the third preset temperature T3, control both the intake throttle valve and the exhaust throttle valve to open, that is, the thermal management mode is started and the exhaust gas aftertreatment mode is also started.

[0056] Specifically, the opening degrees of both the intake throttle valve and the exhaust throttle valve are determined according to the preset engine speed and the preset engine torque of the engine.

[0057] S33: Control the intake throttle valve, the exhaust throttle valve, and the recirculation bypass control valve to be all closed, control the recirculation control valve to be open, and the opening degree of the recirculation control valve is a preset opening degree; When the judgment result of S30 is no, that is, the exhaust gas temperature at the intake port of the aftertreatment system is greater than or equal to the third preset temperature T3, it indicates that the exhaust gas temperature of the exhaust gas discharged by the engine fuel system is relatively high. At this time, control the intake throttle valve and the exhaust throttle valve to be all closed, stop the exhaust gas aftertreatment, and exit the thermal management mode. At the same time, control the recirculation bypass control valve to be closed and the recirculation control valve to be open, so that the high-temperature exhaust gas passes through the EGR cooler for cooling and then re-enters the engine fuel system for closed-loop control.

[0058] Optionally, as Figure 4 shown, S31 (control the opening or closing of the recirculation control valve and the recirculation bypass control valve according to the coolant temperature and the exhaust gas temperature at the intake port of the aftertreatment system) specifically includes the following steps: S310: Judge whether the coolant temperature is greater than the first preset temperature T1; Specifically, the first preset temperature is calibrated according to experience. For example, the first preset temperature T1 is 60 - 70 °C. Optionally, the first preset temperature T1 is 65 °C.

[0059] When the judgment result of S310 is yes, that is, when the coolant temperature is greater than the first preset temperature T1, execute S312 or S314 or S313.

[0060] When the judgment result of S310 is no, that is, when the coolant temperature is less than or equal to the first preset temperature T1, execute S311.

[0061] S311: Control the recirculation control valve to be closed and control the recirculation bypass control valve to be open; When the coolant temperature is less than or equal to the first preset temperature T1, control the recirculation control valve to be closed and the recirculation bypass control valve to be open, that is, the exhaust gas generated by the engine fuel system does not pass through the EGR cooler for cooling, and the exhaust gas directly passes through the bypass pipeline where the recirculation bypass control valve is located (one end of the bypass pipeline is connected to the exhaust manifold of the engine, and the other end is connected to the intake manifold of the engine) for closed-loop control.

[0062] Specifically, the opening degree of the recirculation bypass control valve can be determined according to the preset torque and preset speed of the engine. For example, according to Figure 5 shown in the area in the torque and speed to calculate the opening degree of the recirculation bypass control valve, that is, the opening degree of the recirculation bypass control valve can be calculated according to any set of torque and speed in the area in.

[0063] Correspondingly, in this case, the specific calculation methods for the preset of the exhaust throttle valve and the preset opening degree of the intake throttle valve in S32 can be as follows: According to Figure 6 the torque and rotational speed in the region calculate the preset opening degree of the intake throttle valve, that is, the preset opening degree of the intake throttle valve can be calculated according to any set of torque and rotational speed in the region .

[0064] According to Figure 6 the torque and rotational speed in the region calculate the preset of the exhaust throttle valve, that is, the preset of the exhaust throttle valve can be calculated according to any set of torque and rotational speed in the region .

[0065] Correspondingly, in this case, the specific calculation methods for the preset of the exhaust throttle valve and the preset opening degree of the intake throttle valve in S32 can be as follows: According to Figure 6 the torque and rotational speed in the region calculate the preset opening degree of the intake throttle valve, that is, the preset opening degree of the intake throttle valve can be calculated according to any set of torque and rotational speed in the region .

[0066] According to Figure 6 the torque and rotational speed in the region calculate the preset of the exhaust throttle valve, that is, the preset of the exhaust throttle valve can be calculated according to any set of torque and rotational speed in the region .

[0067] S312: When the exhaust gas temperature at the intake port of the aftertreatment system continuously remains lower than the second preset temperature and the duration is greater than the first preset duration, control the recirculation bypass control valve to conduct and control the recirculation control valve to cut off; Specifically, the second preset temperature is 180 - 220 °C. Optionally, the second preset temperature is 200 °C.

[0068] When the exhaust gas temperature at the intake port of the aftertreatment system continuously remains lower than the second preset temperature T2 and the duration is greater than the first preset duration, that is, the exhaust gas temperature at the intake port of the aftertreatment system is long-term lower than the second preset temperature, then control the recirculation bypass control valve to conduct and control the recirculation control valve to cut off. The exhaust gas generated by the engine fuel system does not pass through the EGR cooler for cooling, and the exhaust gas directly conducts closed-loop control through the bypass pipeline where the recirculation bypass control valve is located.

[0069] Correspondingly, in this case, the specific calculation methods for the preset of the exhaust throttle valve and the preset opening degree of the intake throttle valve in S32 can be as follows: According to Figure 6 the torque and rotational speed in the region to calculate the preset opening degree of the intake throttle valve, that is, the preset opening degree of the intake throttle valve can be calculated according to any set of torque and rotational speed in the region .

[0070] According to Figure 6 the torque and rotational speed in the region to calculate the preset of the exhaust throttle valve, that is, the preset of the exhaust throttle valve can be calculated according to any set of torque and rotational speed in the region .

[0071] S313: When the exhaust gas temperature at the intake port of the after-treatment system continuously remains lower than the second preset temperature T2 and the continuous duration is less than or equal to the first preset duration, control the recirculation bypass control valve to cut off the passage, control the recirculation control valve to conduct, and the opening degree of the recirculation control valve is the preset opening degree.

[0072] When the exhaust gas temperature at the intake port of the after-treatment system continuously remains lower than the second preset temperature T2 and the continuous duration is less than or equal to the first preset duration, that is, when the exhaust gas temperature at the intake port of the after-treatment system is short-term lower than the second preset temperature, control the recirculation bypass control valve to cut off the passage, control the recirculation control valve to conduct, and the exhaust gas generated by the engine fuel system is cooled by the EGR cooler and then undergoes closed-loop control.

[0073] Specifically, the opening degree of the recirculation control valve is the preset opening degree, and this preset opening degree can be calculated according to the preset exhaust gas flow rate.

[0074] Correspondingly, in this case, the preset opening degree of the exhaust throttle valve and the specific calculation methods for the intake throttle valve in S32 can be as follows: According to Figure 6 the torque and rotational speed in the region to calculate the preset opening degree of the intake throttle valve, that is, the preset opening degree of the intake throttle valve can be calculated according to any set of torque and rotational speed in the region .

[0075] According to Figure 6 the torque and rotational speed in the region to calculate the preset opening degree of the exhaust throttle valve, that is, the preset opening degree of the exhaust throttle valve can be calculated according to any set of torque and rotational speed in the region .

[0076] S314: When the waste gas temperature at the intake port of the post-treatment system is greater than the second preset temperature T2 and less than the third preset temperature T3, control the recirculation bypass control valve to cut off the passage, control the recirculation control valve to conduct, and the opening degree of the recirculation control valve is the preset opening degree.

[0077] When the waste gas temperature at the intake port of the post-treatment system is greater than the second preset temperature T2 and less than the third preset temperature T3, the waste gas generated by the engine fuel system is cooled by the EGR cooler and then undergoes closed-loop control.

[0078] Correspondingly, in this case, the specific calculation methods for the preset of the exhaust throttle valve and the preset opening degree of the intake throttle valve in S32 can be as follows: According to Figure 6 the torque and rotational speed in the region calculate the preset opening degree of the intake throttle valve, that is, the preset opening degree of the intake throttle valve can be calculated according to any set of torque and rotational speed in the region calculate the preset opening degree of the intake throttle valve.

[0079] According to Figure 6 the torque and rotational speed in the region calculate the preset opening degree of the exhaust throttle valve, that is, the preset opening degree of the exhaust throttle valve can be calculated according to any set of torque and rotational speed in the region calculate the preset opening degree of the exhaust throttle valve.

[0080] In another embodiment of the present application, as Figure 7 shown, wherein, during the post-treatment process of the starting waste gas (that is, when both the exhaust throttle valve and the intake throttle valve are conducting), the control method for the close-coupled selective catalytic reduction device ccSCR in the waste gas post-treatment system includes the following steps, that is, the thermal management control method further includes: S60: Query the corresponding first set conversion rate in the preset database according to the waste gas flow rate and the first waste gas temperature at the intake port of the close-coupled selective catalytic reduction device; Specifically, the first waste gas temperature can be detected by a temperature sensor provided at the intake port of the close-coupled selective catalytic reduction device ccSCR.

[0081] S61: Calculate the first feedforward urea injection amount according to the first nitrogen oxide content and the first set conversion rate in the waste gas at the intake port of the close-coupled selective catalytic reduction device; Specifically, the first nitrogen oxide content can be detected by a first nitrogen oxide sensor NO x 1 provided at the intake port of the close-coupled selective catalytic reduction device ccSCR.

[0082] S62: Calculate the actual conversion rate of the close-coupled selective catalytic reduction device based on the first nitrogen oxide content in the waste gas at the inlet of the close-coupled selective catalytic reduction device and the second nitrogen oxide content in the waste gas at the inlet of the selective catalytic reduction device. Specifically, the second nitrogen oxide content can be detected by a second nitrogen oxide sensor NO x 2 provided at the inlet of the selective catalytic reduction device SCR.

[0083] S63: Calculate the first corrected urea injection amount based on the actual conversion rate and the first set conversion rate. S64: Calculate the total urea injection amount of the close-coupled selective catalytic reduction device based on the first feedforward urea injection amount and the first corrected urea injection amount, and control the operation of the close-coupled selective catalytic reduction device with the total urea injection amount.

[0084] In another embodiment of the present application, during the start of the post-treatment process of the waste gas (i.e., when both the exhaust throttle valve and the intake throttle valve are open), the control method for the selective catalytic reduction device SCR in the waste gas post-treatment system includes the following steps, that is, the thermal management control method further includes: S70: Query the corresponding second set conversion rate in the preset database according to the waste gas flow rate at the inlet of the selective catalytic reduction device and the second waste gas temperature. S71: Calculate the second feedforward urea injection amount based on the second nitrogen oxide content in the waste gas at the inlet of the selective catalytic reduction device and the second set conversion rate. S72: Calculate the actual conversion rate of the selective catalytic reduction device based on the second nitrogen oxide content in the waste gas at the inlet of the selective catalytic reduction device and the third nitrogen oxide content in the waste gas at the outlet of the selective catalytic reduction device. S73: Calculate the second corrected urea injection amount based on the actual conversion rate and the second set conversion rate. S74: Calculate the total urea injection amount of the selective catalytic reduction device based on the second feedforward urea injection amount and the second corrected urea injection amount, and control the operation of the selective catalytic reduction device with the total urea injection amount.

[0085] In another embodiment of the present application, during the start of the post-treatment process of the waste gas (i.e., when both the exhaust throttle valve and the intake throttle valve are open), the control method for the diesel particulate filter DPF in the waste gas post-treatment system includes the following steps, that is, the thermal management control method further includes: S80: Calculate the pressure difference according to the first waste gas pressure at the inlet of the diesel particulate filter DPF and the second waste gas pressure at the outlet of the diesel particulate filter DPF. S81: Calculate the internal carbon loading of the diesel particulate filter (DPF) based on the pressure difference and the exhaust gas flow rate at the intake port of the DPF. S82: When the internal carbon loading exceeds the regeneration limit value, control the DPF to enter the regeneration mode.

[0086] Specifically, the regeneration mode is as follows: By post-injecting fuel into the cylinder, heat is released by combustion in the diesel oxidation catalyst (DOC) to increase the temperature at the intake port of the DPF, complete the oxidation of carbon in the DPF, and reduce the pressure difference of the DPF.

[0087] As the third aspect of this application, this application also provides a vehicle, including the above-mentioned engine emission system; and a thermal management controller, which is used to execute the above-mentioned thermal management control method.

[0088] The method in this application can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions of this application are executed in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user device, a core network device, an OAM, or other programmable devices.

[0089] The computer program product can be written in any combination of one or more programming languages for programming code to execute the operations of the embodiments of this application. The programming languages include object-oriented programming languages such as Java, C++, etc., and also include conventional procedural programming languages such as the "C" language or similar programming languages. The programming code can be executed entirely on the user computing device, partially on the user device, executed as an independent software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0090] Computer programs or instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another. For example, computer programs or instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center in a wired or wireless manner. The computer-readable storage medium can be any available medium that a computer can access, or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; it can also be an optical medium, such as a digital video disc; or it can be a semiconductor medium, such as a solid-state drive. The computer-readable storage medium can be a volatile or non-volatile storage medium, or can include both volatile and non-volatile types of storage media.

[0091] In addition, an embodiment of the present application can also be a storage medium on which a computer program is stored, and the computer program is executed by a processor to perform the steps in a thermal management control method of an engine emission system described in any of the above embodiments of this specification: For the foregoing method embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present application is not limited by the described order of actions, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present application.

[0092] It should be noted that the embodiments in this specification are all described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other. For device embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiments.

[0093] The steps in the methods of the embodiments of the present application can be adjusted, combined, and deleted according to actual needs. The technical features recorded in each embodiment can be replaced or combined. The devices in the embodiments of the present application can be combined, divided, and deleted according to actual needs.

[0094] Those skilled in the art may further realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of the two. To clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described according to functions in the above description. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0095] The steps of the methods or algorithms described in combination with the embodiments disclosed herein can be directly implemented by hardware, software units executed by a processor, or a combination of the two. The software units can be placed in a random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium well-known in the technical field.

[0096] Finally, it should also be noted that in this document, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0097] The above description of the disclosed embodiments enables those skilled in the art to implement or use this application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An engine emission system, characterized in that, Comprising: An engine fuel system; An exhaust gas recirculation cooling system, the exhaust gas recirculation cooling system including an exhaust gas recirculation cooler, a recirculation control valve, and a supercharger, the intake port of the recirculation control valve being in communication with the exhaust manifold of the engine, the outlet port of the recirculation control valve being in communication with the intake port of the exhaust gas recirculation cooler, and the intake port of the supercharger being in communication with the exhaust manifold of the engine; A thermal management system, the thermal management system including an intake throttle valve, an exhaust throttle valve, and a recirculation bypass control valve, the intake port of the recirculation bypass control valve being in communication with the exhaust manifold of the engine, the outlet port of the recirculation bypass control valve being in communication with the intake manifold of the engine and the outlet port of the exhaust gas recirculation cooler, the outlet port of the intake throttle valve being in communication with the intake manifold of the engine, and the intake port of the exhaust throttle valve being in communication with the outlet port of the supercharger; and ； A post-treatment system, the intake port of the post-treatment system being in communication with the outlet port of the exhaust throttle valve, and the post-treatment system being configured to treat the exhaust gas discharged from the engine.

2. The engine emission system according to claim 1, characterized in that, The post-treatment system includes: An oxidation catalytic converter configured to convert HC and CO in the exhaust gas and convert NO to NO2; A catalytic conversion device configured to catalytically convert nitrogen oxides in the exhaust gas; A particulate trap configured to trap carbon particles in the exhaust gas.

3. The engine emission system according to claim 2, wherein The catalytic conversion device includes: A close-coupled selective catalytic reduction device, the intake port of the close-coupled selective catalytic reduction device being in communication with the outlet port of the exhaust throttle valve, and the exhaust port of the close-coupled selective catalytic reduction device being in communication with the intake port of the oxidation catalytic converter; and A selective catalytic reduction device, the intake port of the selective catalytic reduction device being in communication with the outlet port of the particulate trap.

4. The engine emission system according to claim 2, wherein, The post-treatment system further includes: A plurality of temperature sensors configured to detect the temperature of the exhaust gas at different stages.

5. The engine emission system according to claim 1, characterized in that, The exhaust gas recirculation cooling system further includes: A flow sensor disposed downstream of the intake throttle valve and configured to detect the recirculation gas flow rate of the recirculation gas after the intake throttle valve, An intake air temperature sensor disposed downstream of the intake throttle valve and configured to detect the temperature of the recirculation gas entering the intake system of the engine; An intake air pressure sensor disposed downstream of the intake throttle valve and configured to detect the pressure of the recirculation gas entering the intake system of the engine.

6. A thermal management control method for an engine emission system, characterized in that The thermal management control method is used to control the engine emission system according to claim 1, wherein the thermal management control method includes: Obtaining the temperature of the coolant of the engine; Obtaining the temperature of the exhaust gas at the intake port of the post-treatment system; Controlling the opening or closing of the recirculation control valve, the recirculation bypass control valve, the intake throttle valve, and the exhaust throttle valve according to the temperature of the coolant and the temperature of the exhaust gas at the intake port of the post-treatment system to control the operation of the post-treatment system and / or the operation of the exhaust gas recirculation cooling system.

7. The thermal management control method for an engine emission system according to claim 6, wherein Controlling the opening or closing of the recirculation control valve, recirculation bypass control valve, intake throttle valve, and exhaust throttle valve according to the temperature of the coolant and the temperature of the exhaust gas at the intake port of the aftertreatment system includes: When the temperature of the exhaust gas at the intake port of the aftertreatment system is greater than or equal to the third preset temperature, controlling the intake throttle valve, exhaust throttle valve, and recirculation bypass control valve to be closed, and controlling the recirculation control valve to be opened, and the opening degree of the recirculation control valve is the preset opening degree; or; When the temperature of the exhaust gas at the intake port of the aftertreatment system is less than the third preset temperature, controlling the opening or closing of the recirculation control valve and recirculation bypass control valve according to the temperature of the coolant and the temperature of the exhaust gas at the intake port of the aftertreatment system; and determining the opening degrees of the intake throttle valve and the exhaust throttle valve according to the preset engine speed and preset torque, and controlling the intake throttle valve to be opened according to the opening degree of the intake throttle valve, and controlling the exhaust throttle valve to be opened according to the opening degree of the exhaust throttle valve.

8. The thermal management control method of the engine emission system according to claim 7, characterized in that, Controlling the opening or closing of the recirculation control valve and recirculation bypass control valve according to the temperature of the coolant and the temperature of the exhaust gas at the intake port of the aftertreatment system includes: When the temperature of the coolant is less than or equal to the first preset temperature, controlling the recirculation control valve to be closed and controlling the recirculation bypass control valve to be opened; or; When the temperature of the coolant is greater than the first preset temperature, and the temperature of the exhaust gas at the intake port of the aftertreatment system continuously remains lower than the second preset temperature, and the continuous duration is greater than the first preset duration, controlling the recirculation bypass control valve to be opened and controlling the recirculation control valve to be closed; or; When the temperature of the coolant is greater than the first preset temperature, and the temperature of the exhaust gas at the intake port of the aftertreatment system continuously remains lower than the second preset temperature, and the continuous duration is less than or equal to the first preset duration, controlling the recirculation bypass control valve to be closed and controlling the recirculation control valve to be opened, and the opening degree of the recirculation control valve is the preset opening degree.

9. The thermal management control method of the engine emission system according to claim 7, characterized in that, The aftertreatment system includes: an oxidation catalytic converter for converting HC and CO in the exhaust gas and converting NO into NO2; a close-coupled selective catalytic reduction device, the intake port of the close-coupled selective catalytic reduction device is communicated with the outlet of the exhaust throttle valve, the exhaust port of the close-coupled selective catalytic reduction device is communicated with the intake port of the oxidation catalytic converter, a selective catalytic reduction device, the intake port of the selective catalytic reduction device is communicated with the outlet of the particulate matter trap; a particulate matter trap for trapping carbon particles in the exhaust gas; Wherein, the thermal management control method further includes: Querying the corresponding first set conversion rate in a preset database according to the exhaust gas flow rate and the first exhaust gas temperature at the intake port of the close-coupled selective catalytic reduction device; Calculating the first feedforward urea injection amount according to the first nitrogen oxide content in the exhaust gas at the intake port of the close-coupled selective catalytic reduction device and the first set conversion rate; Calculate the actual conversion rate of the close-coupled selective catalytic reduction device according to the content of the first nitrogen oxides in the exhaust gas at the intake port of the close-coupled selective catalytic reduction device and the content of the second nitrogen oxides in the exhaust gas at the intake port of the selective catalytic reduction device; Calculate the first corrected urea injection amount according to the actual conversion rate and the first set conversion rate; Calculate the total urea injection amount of the close-coupled selective catalytic reduction device according to the first feedforward urea injection amount and the first corrected urea injection amount, and control the operation of the close-coupled selective catalytic reduction device with the total urea injection amount.

10. A vehicle, characterized in that, Comprising: The engine emission system according to any one of claims 1-5; A thermal management controller for performing the thermal management control method of the engine emission system according to any one of claims 6-9.

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