An engine emission system and its thermal management control method, and a vehicle

Abstract

This application provides an engine emission system and its thermal management control method, as well as a vehicle, solving the technical problem that the large fuel injection volume in the existing engine thermal management mode leads to high fuel consumption. The engine emission system provided in this application, by setting a recirculation control valve, a recirculation bypass control valve, an exhaust throttle valve, and an intake throttle valve, controls the opening or closing of these valves based on the engine coolant temperature and the exhaust gas temperature at the intake port of the aftertreatment system. This controls the operation of the aftertreatment system and / or the exhaust gas recirculation cooling system, thereby regulating the temperature of the recirculated exhaust gas entering the engine fuel system. This achieves optimal exhaust gas temperature increase and fuel consumption reduction under different conditions by using appropriate thermal management methods.

Description

Technical Field

[0001] This application relates to the field of automotive exhaust emission technology, specifically to an engine emission system and its thermal management control method, and a vehicle. Background Technology

[0002] Automobile exhaust is the waste gas produced when a car is in use. It contains hundreds of different compounds, including pollutants such as particulate matter, carbon monoxide, carbon dioxide, hydrocarbons, nitrogen oxides, lead, and sulfur oxides. Therefore, the exhaust gas produced by a car engine often needs to be treated before it is emitted.

[0003] When the inlet temperature of the engine exhaust aftertreatment system is low, it cannot effectively convert harmful pollutants, resulting in excessive emissions from the engine and the entire vehicle. Therefore, in engine thermal management mode, more fuel is injected into the engine when the inlet temperature of the exhaust aftertreatment system does not meet the minimum temperature requirement, so that the temperature of the aftertreatment system can be rapidly raised to the operating temperature that can effectively convert harmful pollutants and reduce pollutant emissions. As a result, the large amount of fuel injected in engine thermal management mode 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 achieves the optimization of exhaust gas temperature increase and fuel consumption increase by setting up a recirculation control valve, a recirculation bypass control valve, an exhaust throttle valve and an intake throttle valve to coordinate with each other, thereby using the corresponding thermal management methods under different conditions.

[0005] To achieve the above objectives, this application provides an engine emission system, comprising:

[0006] Engine fuel system;

[0007] An exhaust gas recirculation cooling system includes an exhaust gas recirculation cooler, a recirculation control valve, and a turbocharger. The inlet of the recirculation control valve is connected to the exhaust manifold of the engine, the outlet of the recirculation control valve is connected to the inlet of the exhaust gas recirculation cooler, and the inlet of the turbocharger is connected to the exhaust manifold of the engine.

[0008] A thermal management system, comprising an intake throttle valve, an exhaust throttle valve, and a recirculation bypass control valve, wherein 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 turbocharger; and;

[0009] An aftertreatment system, wherein the air intake of the aftertreatment system is connected to the air outlet of the exhaust throttle valve, and the aftertreatment system is used to treat the exhaust gas discharged from the engine fuel system.

[0010] In one embodiment of this application, the post-processing system includes:

[0011] An oxidation catalytic converter, wherein the oxidation catalytic converter is used to convert HC and CO in waste gas and convert NO into NO2;

[0012] A catalytic conversion device, wherein the catalytic conversion device is used for the catalytic conversion of nitrogen oxides in waste gas;

[0013] A particulate matter trap for capturing carbon particles in exhaust gas.

[0014] In one embodiment of this application, the catalytic conversion device includes:

[0015] A tightly coupled selective catalytic converter, wherein the inlet of the tightly coupled selective catalytic converter is connected to the outlet of the exhaust throttle valve, and the exhaust port of the tightly coupled selective catalytic converter is connected to the inlet of the oxidation catalytic converter; and;

[0016] A selective catalytic conversion device, wherein the air inlet of the selective catalytic conversion device is connected to the air outlet of the particulate matter trap.

[0017] In one embodiment of this application, the post-processing system further includes:

[0018] Multiple temperature sensors are used to detect the temperature of the exhaust gas at different stages.

[0019] In one embodiment of this application, the exhaust gas recirculation cooling system further includes:

[0020] A flow sensor is located downstream of the intake throttle valve, and the flow sensor is used to detect the recirculated air flow rate after the intake throttle valve.

[0021] An intake air temperature sensor is located downstream of the intake throttle valve and is used to detect the temperature of the recirculated air entering the intake system of the engine.

[0022] An intake pressure sensor is located downstream of the intake throttle valve and is used to detect the pressure of the recirculated air entering the engine's intake system.

[0023] As a second aspect of this application, this application also provides a thermal management control method for an engine emission system, the thermal management control method being used to control the aforementioned engine emission system, wherein the thermal management control method includes:

[0024] To obtain the temperature of the engine coolant;

[0025] Obtain the exhaust gas temperature at the air inlet of the aftertreatment system;

[0026] Based on the temperature of the coolant and the temperature of the exhaust gas at the inlet of the aftertreatment system, the recirculation control valve, the recirculation bypass control valve, the intake throttle valve, and the exhaust throttle valve are controlled to open or close, thereby controlling the operation of the aftertreatment system and / or the operation of the exhaust gas recirculation cooling system.

[0027] In one embodiment of this application, controlling the opening or closing of the recirculation control valve, recirculation bypass control valve, intake throttle valve, and exhaust throttle valve based on the temperature of the coolant and the exhaust gas temperature at the intake of the aftertreatment system includes:

[0028] When the exhaust gas temperature at the inlet of the aftertreatment system is greater than or equal to the third preset temperature, the intake throttle valve, exhaust throttle valve, and recirculation bypass control valve are all shut off, and the recirculation control valve is opened, with the opening degree of the recirculation control valve being a preset opening degree; or;

[0029] When the exhaust gas temperature at the intake of the aftertreatment system is lower than the third preset temperature, the recirculation control valve and the recirculation bypass control valve are controlled to open or close based on the temperature of the coolant and the exhaust gas temperature at the intake of the aftertreatment system; and the opening degree of the intake throttle valve and the exhaust throttle valve are determined based on the preset engine speed and preset torque, and the intake throttle valve is controlled to open based on the opening degree of the intake throttle valve, and the exhaust throttle valve is controlled to open based on the opening degree of the exhaust throttle valve.

[0030] In one embodiment of this application, controlling the opening or closing of the recirculation control valve and the recirculation bypass control valve based on the temperature of the coolant and the exhaust gas temperature at the inlet of the aftertreatment system includes:

[0031] When the temperature of the coolant is less than or equal to a first preset temperature, the recirculation control valve is shut off, and the recirculation bypass control valve is opened; or;

[0032] When the temperature of the coolant is greater than the first preset temperature, and the exhaust gas temperature at the air inlet of the aftertreatment system is consistently lower than the second preset temperature for a duration longer than the first preset duration, the recirculation bypass control valve is opened, and the recirculation control valve is closed; or;

[0033] When the temperature of the coolant is greater than the first preset temperature, and the temperature of the exhaust gas at the air inlet of the aftertreatment system is continuously lower than the second preset temperature for a duration less than or equal to the first preset duration, the recirculation bypass control valve is controlled to shut off, and the recirculation control valve is controlled to open, with the opening degree of the recirculation control valve being a preset opening degree.

[0034] In one embodiment of this application, the aftertreatment system includes: an oxidation catalytic converter for converting nitrogen oxides in waste gas into nitrogen and water; a tightly coupled selective catalytic converter, the inlet of which is connected to the outlet of the exhaust throttle valve, and the outlet of which is connected to the inlet of the oxidation catalytic converter; a selective catalytic converter, the inlet of which is connected to the outlet of the particulate matter filter; and a particulate matter filter for capturing carbon particles in the waste gas.

[0035] The thermal management control method further includes:

[0036] Based on the exhaust gas flow rate and first exhaust gas temperature at the inlet of the tightly coupled selective catalytic converter, the corresponding first set conversion rate is queried from the preset database.

[0037] The first feedforward urea injection quantity is calculated based on the content of the first nitrogen oxide in the exhaust gas at the inlet of the tightly coupled selective catalytic converter and the first set conversion rate.

[0038] The actual conversion rate of the tightly coupled selective catalytic converter is calculated based on the content of the first nitrogen oxide in the exhaust gas at the inlet of the tightly coupled selective catalytic converter and the content of the second nitrogen oxide in the exhaust gas at the inlet of the selective catalytic converter.

[0039] Calculate the first corrected urea injection amount based on the actual conversion rate and the first set conversion rate;

[0040] The total urea injection amount of the tightly coupled selective catalytic converter is calculated based on the first feedforward urea injection amount and the first corrected urea injection amount, and the operation of the tightly coupled selective catalytic converter is controlled by the total urea injection amount.

[0041] As a third aspect of this application, this application also provides a vehicle, including:

[0042] The engine emission system described above;

[0043] A thermal management controller, which is used to execute the thermal management control method described above.

[0044] The engine emission system provided in this application, by setting a recirculation control valve, a recirculation bypass control valve, an exhaust throttle valve, and an intake throttle valve, and controlling the opening or closing of the recirculation control valve, recirculation bypass control valve, intake throttle valve, and exhaust throttle valve according to the engine coolant temperature and the exhaust gas temperature at the intake port of the aftertreatment system, controls the operation of the aftertreatment system and / or the exhaust gas recirculation cooling system. This allows the exhaust gas discharged from the engine fuel system to achieve thermal management through exhaust gas aftertreatment and / or exhaust gas recirculation. When using exhaust gas recirculation for thermal management, the opening or closing of the recirculation control valve and recirculation bypass control valve can also be adjusted to determine whether the exhaust gas is cooled by the EGR cooler during exhaust gas recirculation, thereby regulating the temperature of the recirculated exhaust gas entering the engine fuel system. This allows for the use of appropriate thermal management methods under different conditions to optimize the increase in exhaust gas temperature and fuel consumption. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0046] Figure 1 This is a schematic diagram of an engine emission system provided in an embodiment of this application.

[0047] Figure 2 The diagram shown is a schematic flowchart of a thermal management control method for an engine emission system according to an embodiment of this application.

[0048] Figure 3 The diagram shown is a flowchart illustrating a thermal management control method for an engine emission system according to another embodiment of this application.

[0049] Figure 4 The diagram shown is a flowchart illustrating a thermal management control method for an engine emission system according to two other embodiments of this application.

[0050] Figure 5 The diagram shows the operating area of ​​a recirculation bypass control valve provided in an embodiment of this application.

[0051] Figure 6 The diagram shows the working area of ​​the intake throttle valve and the exhaust throttle valve provided in an embodiment of this application.

[0052] Figure 7The diagram shown is a flowchart illustrating a thermal management control method for an engine emission system according to three other embodiments of this application. Detailed Implementation

[0053] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0054] For ease of description, some of the nouns or terms used in the embodiments of the present invention are explained below:

[0055] DPF: Diesel Particulate Filter, used to capture particulate matter in exhaust gas. When the mass of captured particulate matter reaches a certain level, passive or active regeneration is required to restore the DPF's ability to capture particulate matter.

[0056] SCR: Selectively Catalytic Reduction, which involves injecting urea before the SCR to reduce nitrogen oxides in exhaust emissions.

[0057] DOC: Diesel Oxide Catalyst, installed before the DPF, is used to convert HC, CO, etc. in the exhaust gas, and to oxidize NO in the tail gas to NO2. At the same time, it increases the tail gas temperature and assists the normal operation of the DPF and SCR.

[0058] ccSCR: Closely coupled selective catalytic conversion device, i.e., closely coupled SCR.

[0059] ASC: Ammonia Slip Catalyst, used to oxidize excess ammonia.

[0060] PFM sensor: A flow sensor (Pulse Frequency Modulation Sensor) is a sensor based on pulse frequency modulation technology that can measure the amount of air entering the system based on the Venturi principle.

[0061] EGR cooler: Exhaust Gas Recirculation Valve cooler, a key component used to control the amount of exhaust gas recirculation, mainly for reducing nitrogen oxide (NOx) emissions.

[0062] PM sensor: Particulate Matter Sensor, used to detect the mass of particulate matter after passing through DPF. The particulate matter mass can be used to diagnose whether the DPF is malfunctioning and whether the particulate matter exceeds the standard.

[0063] CAC: Charge Air Cooler (intercooler) cools the high-temperature, high-pressure air after boosting through heat exchange. As a first aspect of this application, this application provides an engine emission system. Figure 1 The diagram shown is a structural schematic of an engine emission system according to an embodiment of this application. Figure 1 As shown, an engine emission system includes:

[0064] Engine fuel system; The engine fuel system includes the engine, fuel pump, leak-free injectors, and pressure regulator. The fuel system employs an electronically controlled high-pressure common rail system with 2500 bar rail pressure control, achieving precise fuel and combustion control. The engine fuel system uses the rail pressure setpoint for closed-loop control of the fuel pump and pressure regulator, controlling engine combustion through injection advance angle, etc.

[0065] The exhaust gas recirculation (EGR) cooling system includes an EGR cooler, a recirculation control valve, and a turbocharger. The inlet of the recirculation control valve is connected to the engine's exhaust manifold, and the outlet of the recirculation control valve is connected to the inlet of the EGR cooler. The inlet of the turbocharger is also connected to the engine's exhaust manifold. The recirculation control valve controls the flow rate (i.e., EGR flow rate) of exhaust gas from the engine's fuel system into the engine's intake system. The EGR cooler cools the high-temperature exhaust gas from the engine's fuel system, increasing the flow rate (i.e., EGR flow rate) of exhaust gas entering the engine's intake system.

[0066] 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 engine's exhaust manifold, and its outlet is connected to both the engine's intake manifold and the exhaust gas recirculation cooler's outlet. The outlet of the intake throttle valve is connected to the engine's intake manifold, and the intake port of the exhaust throttle valve is connected to the turbocharger's outlet. The intake throttle valve reduces the intake air volume and increases the exhaust gas temperature by throttling the intake air. The exhaust throttle valve increases the exhaust back pressure, increasing pumping losses and thus increasing the exhaust gas temperature. By regulating the recirculation bypass control valve, the intake air temperature can be increased during cold-cycle recirculation without using the EGR cooler, thereby increasing the exhaust gas temperature. The thermal management system primarily optimizes temperature increase and fuel consumption based on thermal management methods.

[0067] The aftertreatment system has its intake port connected to the exhaust outlet of the exhaust throttle valve. The aftertreatment system is used to treat the exhaust gases emitted from the engine's fuel system.

[0068] Optionally, the exhaust gas recirculation cooling system also includes a turbocharger with an electronically controlled vent valve. The electronically controlled vent valve is used to control the turbocharger speed from overspeeding due to excessive intake pressure under high load, allowing some exhaust gas to be discharged to the exhaust pipe without passing through the turbocharger.

[0069] The engine emission system provided in this application, by setting a recirculation control valve, a recirculation bypass control valve, an exhaust throttle valve, and an intake throttle valve, and controlling the opening or closing of the recirculation control valve, recirculation bypass control valve, intake throttle valve, and exhaust throttle valve according to the engine coolant temperature and the exhaust gas temperature at the intake port of the aftertreatment system, controls the operation of the aftertreatment system and / or the exhaust gas recirculation cooling system. This allows the exhaust gas discharged from the engine fuel system to achieve thermal management through exhaust gas aftertreatment and / or exhaust gas recirculation. When using exhaust gas recirculation for thermal management, the opening or closing of the recirculation control valve and recirculation bypass control valve can also be adjusted to determine whether the exhaust gas is cooled by the EGR cooler during exhaust gas recirculation, thereby regulating the temperature of the recirculated exhaust gas entering the engine fuel system. This allows for the use of appropriate thermal management methods under different conditions to optimize the increase in exhaust gas temperature and fuel consumption.

[0070] In one embodiment of this application, as Figure 1 As shown, the aftertreatment system includes: an oxidation catalytic converter (DOC), which converts HC, CO, etc. in the waste gas and converts NO into NO2; a catalytic conversion device, which catalytically converts nitrogen oxides in the waste gas; and a particulate filter (DPF), which captures carbon particles in the waste gas.

[0071] Specifically, the catalytic conversion device includes a tightly coupled selective catalytic converter (CCSCR) and a selective catalytic converter (SCR). The CCSCR's inlet is connected to the exhaust outlet of the exhaust throttle valve, and its exhaust outlet is connected to the inlet of the oxidation catalytic converter (DOC). The DOC's outlet is connected to the inlet of the particulate filter (DPF). The SCR's inlet is connected to the outlet of the DPF. The SCR's outlet is connected to the inlet of a particulate sensor (PM sensor). The PM sensor measures the particulate matter mass after passing through the DPF, used to diagnose DPF failure and whether particulate matter levels exceed limits.

[0072] Specifically, the aftertreatment system also includes multiple temperature sensors used to detect the temperature of the exhaust gas at various stages, such as... Figure 1 As 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 tightly coupled selective catalytic converter CCSCR); a fifth temperature sensor T5 for detecting the temperature of the exhaust gas at the outlet of the tightly coupled selective catalytic converter CCSCR (i.e., the inlet of the oxidation catalytic converter DOC); a seventh temperature sensor T7 for detecting the temperature of the exhaust gas at the outlet of the particulate filter DPF (i.e., the inlet of the selective catalytic converter SCR); and an eighth temperature sensor T8 for detecting the temperature of the exhaust gas at the outlet of the selective catalytic converter SCR.

[0073] Specifically, the aftertreatment system also includes multiple nitrogen oxide sensors to detect the nitrogen oxide content in the exhaust gas, such as... Figure 1 As shown, the post-treatment system includes a first nitrogen oxide sensor (NO). x 1. A sensor for detecting nitrogen oxides (NOx) in the exhaust gas at the inlet of a tightly coupled selective catalytic converter (CCSCR); 2. A second nitrogen oxide sensor. x 2. A sensor for detecting the content of nitrogen oxides in the exhaust gas at the outlet of a particulate filter (DPF).

[0074] This application further reduces the content of nitrogen oxides in exhaust gas by setting up a two-stage SCR to treat NOx emissions and suppress N2O generation.

[0075] In one embodiment of this application, as Figure 1 As shown, the exhaust gas recirculation cooling system also includes:

[0076] The flow sensor (PFM sensor) is located downstream of the intake throttle valve. The flow sensor detects the recirculated air flow rate after the intake throttle valve.

[0077] Intake air temperature sensor T2 is located downstream of the intake throttle valve and is used to detect the temperature of the recirculated air entering the engine's intake system.

[0078] Intake pressure sensor P2 is located downstream of the intake throttle valve and is used to detect the pressure of the recirculated air entering the engine's intake system.

[0079] In one embodiment of this application, as Figure 1As shown, the engine emission system also includes: an air purifier for purifying the air entering the exhaust gas recirculation cooling system; a CAC (intercooler) for cooling the high-temperature, high-pressure air after boosting through heat exchange; and a PFM sensor for measuring the air intake volume based on the Venturi principle.

[0080] As a second aspect of this application, this application also provides a thermal management control method for an engine emission system, used to control the aforementioned engine emission system. Figure 2 The diagram shown is a schematic flowchart of a thermal management control method for an engine emission system according to an embodiment of this application. Figure 2 As shown, the thermal management control method for the engine emission system specifically includes the following steps:

[0081] S1: Obtain the temperature of the engine coolant;

[0082] When the vehicle is cold-started, the engine coolant temperature is obtained, which can be detected by a temperature sensor.

[0083] S2: Obtain the exhaust gas temperature at the air inlet of the aftertreatment system;

[0084] Specifically, the exhaust gas temperature at the air inlet of the aftertreatment system can be detected by a temperature sensor located at the air inlet of the aftertreatment system.

[0085] S3: Based on the temperature of the coolant and the exhaust gas temperature at the inlet of the aftertreatment system, control the opening or closing of the recirculation control valve, recirculation bypass control valve, intake throttle valve and exhaust throttle valve to control the operation of the aftertreatment system and / or the exhaust gas recirculation cooling system.

[0086] Based on the temperature of the coolant and the exhaust gas temperature at the inlet of the aftertreatment system, the recirculation control valve, recirculation bypass control valve, intake throttle valve, and exhaust throttle valve are controlled to open or close, thereby controlling the operation of the aftertreatment system and / or the exhaust gas recirculation cooling system.

[0087] This application provides a thermal management control method for an engine emission system. Based on the engine coolant temperature and the exhaust gas temperature at the intake of the aftertreatment system, the method controls the opening or closing of a recirculation control valve, a recirculation bypass control valve, an intake throttle valve, and an exhaust throttle valve to control the operation of the aftertreatment system and / or the exhaust gas recirculation cooling system. This allows the exhaust gas discharged from the engine fuel system to undergo exhaust gas aftertreatment and / or exhaust gas recirculation for thermal management. When using exhaust gas recirculation for thermal management, the opening or closing of the recirculation control valve and the recirculation bypass control valve can be adjusted to determine whether the exhaust gas is cooled by the EGR cooler during recirculation, thereby regulating the temperature of the recirculated exhaust gas entering the engine fuel system. This allows for the use of appropriate thermal management methods under different conditions to optimize the increase in exhaust gas temperature and fuel consumption.

[0088] In one embodiment of this application, as Figure 3 As shown, S3 (controlling the opening or closing of the recirculation control valve, recirculation bypass control valve, intake throttle valve, and exhaust throttle valve based on the coolant temperature and the exhaust gas temperature at the inlet of the aftertreatment system, to control the operation of the aftertreatment system and / or the exhaust gas recirculation cooling system) specifically includes the following steps:

[0089] S30: Determine whether the exhaust gas temperature at the air inlet of the aftertreatment system is lower than the third preset temperature T3;

[0090] Specifically, the third preset temperature T3 is 220-280℃, and optionally, the third preset temperature is 250℃.

[0091] When the judgment result of S30 is yes, that is, the exhaust gas temperature at the intake of the aftertreatment system is less than the third preset temperature T3, it indicates that the exhaust gas temperature discharged from the engine fuel system is relatively low. Therefore, during exhaust gas recirculation, the opening or closing of the recirculation control valve and the recirculation bypass control valve needs to be determined again based on the coolant temperature and the specific exhaust gas temperature at the intake of the aftertreatment system to determine whether the recirculated gas needs EGR cooler cooling, i.e., executing S31-S32. For example, if EGR cooling is required, then the recirculation bypass control valve is opened and the recirculation control valve is closed, so that the exhaust gas discharged from the engine fuel system does not need to be cooled by the EGR cooler during recirculation.

[0092] When the judgment result of S30 is negative, that is, the exhaust gas temperature at the intake of the aftertreatment system is greater than or equal to the third preset temperature T3, it means that the exhaust gas temperature discharged from the engine fuel system is high. Therefore, during exhaust gas recirculation, due to the excessively high exhaust gas temperature, exhaust gas cooling is performed before recirculation. In addition, the aftertreatment system is shut down and the exhaust gas is not heat-treated, that is, S33 is executed.

[0093] S31: 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 air inlet of the aftertreatment system.

[0094] Specifically, when the judgment result of S30 is yes, that is, the exhaust gas temperature at the air intake of the aftertreatment system is less than the third preset temperature T3, it means that the exhaust gas temperature discharged from the engine fuel system is low. At this time, it is necessary to determine whether to activate the cooling function based on the coolant temperature and the exhaust gas temperature at the air intake of the aftertreatment system, that is, whether the exhaust gas needs to be cooled by the EGR cooler.

[0095] S32: Determine the opening degree of the intake throttle valve and the exhaust throttle valve according to the preset engine speed and preset 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.

[0096] When the exhaust gas temperature at the inlet of the aftertreatment system is lower than the third preset temperature T3, the intake throttle valve and the exhaust throttle valve are both turned on, that is, the thermal management mode is started and the exhaust gas aftertreatment mode is also started.

[0097] Specifically, the opening degree of the intake throttle valve and the exhaust throttle valve are determined based on the engine's preset speed and preset torque.

[0098] S33: Control the intake throttle valve, exhaust throttle valve and recirculation bypass control valve to be closed, and control the recirculation control valve to be open, and the opening degree of the recirculation control valve is the preset opening degree;

[0099] When the judgment result of S30 is negative, that is, the exhaust gas temperature at the intake of the aftertreatment system is greater than or equal to the third preset temperature T3, it indicates that the exhaust gas temperature discharged from the engine fuel system is high. At this time, both the intake throttle valve and the exhaust throttle valve are turned off, the exhaust gas aftertreatment stops, and the thermal management mode is exited. At the same time, the recirculation bypass control valve is turned off, and the recirculation control valve is turned on, so that the high-temperature exhaust gas can be cooled by the EGR cooler and then re-enter the engine fuel system for closed-loop control.

[0100] Optional, such as Figure 4 As shown, S31 (controlling the opening or closing of the recirculation control valve and the recirculation bypass control valve based on the coolant temperature and the exhaust gas temperature at the inlet of the aftertreatment system) specifically includes the following steps:

[0101] S310: Determine whether the temperature of the coolant is greater than the first preset temperature T1;

[0102] Specifically, the first preset temperature is calibrated based on experience. For example, the first preset temperature T1 is 60-70℃, or optionally, the first preset temperature T1 is 65℃.

[0103] When the judgment result of S310 is yes, that is, when the temperature of the coolant is greater than the first preset temperature T1, S312, S314, or S313 is executed.

[0104] When the judgment result of S310 is negative, that is, when the temperature of the coolant is less than or equal to the first preset temperature T1, S311 is executed.

[0105] S311: Controls the recirculation control valve to shut off and controls the recirculation bypass control valve to open;

[0106] When the coolant temperature is less than or equal to the first preset temperature T1, the recirculation control valve is turned off and the recirculation bypass control valve is turned on. That is, the exhaust gas generated by the engine fuel system does not pass through the EGR cooler for cooling. Instead, the exhaust gas is directly controlled through the bypass line where the recirculation bypass control valve is located (one end of the bypass line is connected to the engine exhaust manifold, and the other end is connected to the engine intake manifold).

[0107] Specifically, the opening degree of the recirculation bypass control valve can be determined based on the engine's preset torque and preset speed, for example, according to... Figure 5 The area shown The opening degree of the recirculation bypass control valve is calculated based on the torque and speed in the region, that is, it can be determined according to the area. The opening degree of the recirculation bypass control valve is calculated using any set of torques and speeds.

[0108] Correspondingly, in this case, the specific calculation methods for the preset opening of the exhaust throttle valve and the intake throttle valve in S32 can be as follows:

[0109] according to Figure 6 area in The preset opening of the intake throttle valve is calculated based on the torque and speed in the region, which means it can be determined according to the region. The preset opening of the intake throttle valve is calculated using any set of torques and speeds.

[0110] according to Figure 6 area in The preset opening of the exhaust throttle valve is calculated based on the torque and speed in the region, meaning it can be determined according to the area. The preset opening of the exhaust throttle valve is calculated using any set of torques and speeds.

[0111] Correspondingly, in this case, the specific calculation methods for the preset opening of the exhaust throttle valve and the intake throttle valve in S32 can be as follows:

[0112] according to Figure 6 area in The preset opening of the intake throttle valve is calculated based on the torque and speed in the region, which means it can be determined according to the region. The preset opening of the intake throttle valve is calculated using any set of torques and speeds.

[0113] according to Figure 6 area in The preset opening of the exhaust throttle valve is calculated based on the torque and speed in the region, meaning it can be determined according to the area. The preset opening of the exhaust throttle valve is calculated using any set of torques and speeds.

[0114] S312: When the exhaust gas temperature at the inlet of the aftertreatment system is continuously lower than the second preset temperature and the duration is longer than the first preset duration, the recirculation bypass control valve is turned on and the recirculation control valve is turned off.

[0115] Specifically, the second preset temperature is 180-220℃, and optionally, the second preset temperature is 200℃.

[0116] When the exhaust gas temperature at the intake of the aftertreatment system is consistently lower than the second preset temperature T2 and the duration is longer than the first preset duration, i.e., the exhaust gas temperature at the intake of the aftertreatment system is consistently lower than the second preset temperature, the recirculation bypass control valve is turned on and the recirculation control valve is turned off. The exhaust gas generated by the engine fuel system is not cooled by the EGR cooler, and the exhaust gas is directly controlled in a closed loop through the bypass pipeline where the recirculation bypass control valve is located.

[0117] Correspondingly, in this case, the specific calculation methods for the preset opening of the exhaust throttle valve and the intake throttle valve in S32 can be as follows:

[0118] according to Figure 6 area in The preset opening of the intake throttle valve is calculated based on the torque and speed in the region, which means it can be determined according to the region. The preset opening of the intake throttle valve is calculated using any set of torques and speeds.

[0119] according to Figure 6 area in The preset opening of the exhaust throttle valve is calculated based on the torque and speed in the region, meaning it can be determined according to the area. The preset opening of the exhaust throttle valve is calculated using any set of torques and speeds.

[0120] S313: When the exhaust gas temperature at the inlet of the aftertreatment system is continuously lower than the second preset temperature T2 and the duration is less than or equal to the first preset duration, the recirculation bypass control valve is shut off and the recirculation control valve is opened, and the opening degree of the recirculation control valve is the preset opening degree.

[0121] When the exhaust gas temperature at the intake of the aftertreatment system is continuously lower than the second preset temperature T2, and the duration is less than or equal to the first preset duration, that is, when the exhaust gas temperature at the intake of the aftertreatment system is temporarily lower than the second preset temperature, the recirculation bypass control valve is shut off and the recirculation control valve is opened. The exhaust gas generated by the engine fuel system is cooled by the EGR cooler and then subjected to closed-loop control.

[0122] Specifically, the opening degree of the recirculation control valve is a preset opening degree, which can be calculated based on the preset flow rate of the exhaust gas.

[0123] Correspondingly, in this case, the preset opening of the exhaust throttle valve and the specific calculation method of the intake throttle valve in S32 can be:

[0124] according to Figure 6 area in The preset opening of the intake throttle valve is calculated based on the torque and speed in the region, which means it can be determined according to the region. The preset opening of the intake throttle valve is calculated using any set of torques and speeds.

[0125] according to Figure 6 area in The preset opening of the exhaust throttle valve is calculated based on the torque and speed in the region, meaning it can be determined according to the area. The preset opening of the exhaust throttle valve is calculated using any set of torques and speeds.

[0126] S314: When the exhaust gas temperature at the inlet of the aftertreatment system is greater than the second preset temperature T2 and less than the third preset temperature T3, the recirculation bypass control valve is shut off and the recirculation control valve is opened, and the opening degree of the recirculation control valve is the preset opening degree.

[0127] When the exhaust gas temperature at the intake of the aftertreatment system is greater than the second preset temperature T2 and less than the third preset temperature T3, the exhaust gas generated by the engine fuel system is cooled by the EGR cooler and then subjected to closed-loop control.

[0128] Correspondingly, in this case, the specific calculation methods for the preset opening of the exhaust throttle valve and the intake throttle valve in S32 can be as follows:

[0129] according to Figure 6 area in The preset opening of the intake throttle valve is calculated based on the torque and speed in the region, which means it can be determined according to the region. The preset opening of the intake throttle valve is calculated using any set of torques and speeds.

[0130] according to Figure 6 area in The preset opening of the exhaust throttle valve is calculated based on the torque and speed in the region, meaning it can be determined according to the area. The preset opening of the exhaust throttle valve is calculated using any set of torques and speeds.

[0131] In another embodiment of this application, such as Figure 7 As shown, during the after-treatment process of exhaust gas startup (i.e., when both the exhaust throttle valve and the intake throttle valve are open), the control method for the tightly coupled selective catalytic converter (ccSCR) in the exhaust gas after-treatment system includes the following steps, namely, the thermal management control method also includes:

[0132] S60: Based on the exhaust gas flow rate and the first exhaust gas temperature at the inlet of the tightly coupled selective catalytic converter, query the corresponding first set conversion rate in the preset database;

[0133] Specifically, the temperature of the first exhaust gas can be detected by a temperature sensor installed at the inlet of the tightly coupled selective catalytic converter (ccSCR).

[0134] S61: Calculate the first feedforward urea injection quantity based on the first nitrogen oxide content in the exhaust gas at the inlet of the tightly coupled selective catalytic converter and the first set conversion rate;

[0135] Specifically, the first nitrogen oxide content can be detected by a first nitrogen oxide sensor (NOx) installed at the inlet of the tightly coupled selective catalytic converter (ccSCR). x 1. Detected.

[0136] S62: Calculate the actual conversion rate of the tightly coupled selective catalytic converter based on the content of the first nitrogen oxide in the exhaust gas at the inlet of the tightly coupled selective catalytic converter and the content of the second nitrogen oxide in the exhaust gas at the inlet of the selective catalytic converter.

[0137] Specifically, the second nitrogen oxide content can be detected by a second nitrogen oxide sensor (NOx) installed at the inlet of the selective catalytic converter (SCR). x 2. Detected.

[0138] S63: Calculate the first corrected urea injection amount based on the actual conversion rate and the first set conversion rate;

[0139] S64: Calculate the total urea injection amount of the tightly coupled selective catalytic converter based on the first feedforward urea injection amount and the first corrected urea injection amount, and control the operation of the tightly coupled selective catalytic converter with the total urea injection amount.

[0140] In another embodiment of this application, during the start-up of the exhaust gas aftertreatment process (i.e., when both the exhaust throttle valve and the intake throttle valve are open), the control method for the selective catalytic converter (SCR) in the exhaust gas aftertreatment system includes the following steps, namely, the thermal management control method further includes:

[0141] S70: Based on the exhaust gas flow rate and the second exhaust gas temperature at the inlet of the selective catalytic converter, query the corresponding second set conversion rate in the preset database;

[0142] S71: Calculate the second feedforward urea injection quantity based on the content of the second nitrogen oxides in the exhaust gas at the inlet of the selective catalytic converter and the second set conversion rate;

[0143] S72: Calculate the actual conversion rate of the selective catalytic converter based on the content of the second nitrogen oxide in the exhaust gas at the inlet of the selective catalytic converter and the content of the third nitrogen oxide in the exhaust gas at the outlet of the selective catalytic converter.

[0144] S73: Calculate the second corrected urea injection amount based on the actual conversion rate and the second set conversion rate;

[0145] S74: Calculate the total urea injection amount of the selective catalytic converter based on the second feedforward urea injection amount and the second corrected urea injection amount, and control the operation of the selective catalytic converter with the total urea injection amount.

[0146] In another embodiment of this application, during the start-up of the exhaust gas aftertreatment process (i.e., when both the exhaust throttle valve and the intake throttle valve are open), the control method for the particulate filter (DPF) in the exhaust gas aftertreatment system includes the following steps, namely, the thermal management control method further includes:

[0147] S80: Calculate the pressure difference based on the first exhaust gas pressure at the inlet of the particulate filter DPF and the second exhaust gas pressure at the outlet of the particulate filter DPF.

[0148] S81: Calculate the internal carbon load of the particulate filter DPF based on the pressure difference and the exhaust gas flow rate at the inlet of the particulate filter DPF.

[0149] S82: When the internal carbon load exceeds the regeneration limit, control the particulate filter DPF to enter regeneration mode.

[0150] Specifically, the regeneration mode is as follows: fuel is injected into the cylinder and burned in the oxidation catalytic converter (DOC) to release heat, thereby increasing the temperature at the intake of the particulate filter (DPF), completing the oxidation of carbon in the DPF, and reducing the pressure difference of the DPF.

[0151] As a third aspect of this application, this application also provides a vehicle including the engine emission system described above; and a thermal management controller for executing the thermal management control method described above.

[0152] The methods in this application can be implemented, in whole or in part, by software, hardware, firmware, or any combination thereof. When implemented in software, they can be implemented, in whole or in part, as a computer program product. This computer program product includes one or more computer programs or instructions, which, when loaded and executed on a computer, perform all or part of the processes or functions of this application. The computer can be a general-purpose computer, a special-purpose computer, a computer network, network equipment, user equipment, core network equipment, OAM, or other programmable device.

[0153] Computer program products can be written in any combination of one or more programming languages ​​to perform the operations of the embodiments of this application. The programming languages ​​include object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0154] Computer programs or instructions can be stored in or transferred from one computer-readable storage medium to another. For example, a computer program or instructions can be transferred from one website, computer, server, or data center to another via wired or wireless means. A computer-readable storage medium can be any usable medium that a computer can access, or a data storage device such as a server or data center that integrates one or more usable media. Usable media can be magnetic media, such as floppy disks, hard disks, and magnetic tapes; optical media, such as digital video discs; or semiconductor media, such as solid-state drives. The computer-readable storage medium can be volatile or non-volatile, or may include both types.

[0155] Furthermore, embodiments of this application may also be storage media storing a computer program, which is executed by a processor through steps in a thermal management control method for an engine emission system described in any of the above embodiments of this specification:

[0156] For the foregoing method embodiments, in order to simplify the description, they are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, because according to this application, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0157] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For apparatus embodiments, since they are basically similar to method embodiments, the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0158] The steps in the methods of the various embodiments of this application can be adjusted, combined, or deleted according to actual needs, and the technical features described in each embodiment can be replaced or combined. The apparatuses in the various embodiments of this application can be combined, divided, or deleted according to actual needs.

[0159] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software 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 beyond the scope of this application.

[0160] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software unit executed by a processor, or a combination of both. The software unit can be located in random access memory (RAM), main 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 known in the art.

[0161] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0162] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A thermal management control method for an engine emission system, characterized in that, The thermal management control method is used to control an engine emission system, which includes: an engine fuel system; an exhaust gas recirculation (EGR) cooling system, comprising an EGR cooler, a recirculation control valve, and a turbocharger, wherein the inlet of the recirculation control valve is connected to the engine's exhaust manifold, the outlet of the recirculation control valve is connected to the inlet of the EGR cooler, and the inlet of the turbocharger is connected to the engine's exhaust manifold; and a thermal management system, comprising an intake throttle valve, an exhaust throttle valve, and a... The system includes: a recirculation bypass control valve, the inlet of which is connected to the exhaust manifold of the engine, the outlet of which is connected to the intake manifold of the engine and the outlet of the exhaust gas recirculation cooler; the outlet of the intake throttle valve is connected to the intake manifold of the engine; and the inlet of the exhaust throttle valve is connected to the outlet of the turbocharger; and an aftertreatment system, the inlet of which is connected to the outlet of the exhaust throttle valve, the aftertreatment system being used to treat the exhaust gas discharged from the engine. The thermal management control method includes: To obtain the temperature of the engine coolant; Obtain the exhaust gas temperature at the air inlet of the aftertreatment system; Based on the temperature of the coolant and the temperature of the exhaust gas at the inlet of the aftertreatment system, the recirculation control valve, the recirculation bypass control valve, the intake throttle valve, and the exhaust throttle valve are controlled to open or close, so as to control the operation of the aftertreatment system and / or the operation of the exhaust gas recirculation cooling system. The step of controlling the opening or closing of the recirculation control valve, recirculation bypass control valve, intake throttle valve, and exhaust throttle valve based on the temperature of the coolant and the exhaust gas temperature at the intake of the aftertreatment system includes: When the exhaust gas temperature at the inlet of the aftertreatment system is greater than or equal to a third preset temperature, the intake throttle valve, exhaust throttle valve, and recirculation bypass control valve are all shut off, and the recirculation control valve is opened, with the opening degree of the recirculation control valve being a preset opening degree; or; When the exhaust gas temperature at the intake of the aftertreatment system is lower than the third preset temperature, the recirculation control valve and the recirculation bypass control valve are controlled to open or close based on the temperature of the coolant and the exhaust gas temperature at the intake of the aftertreatment system; and the opening degree of the intake throttle valve and the exhaust throttle valve are determined based on the preset engine speed and preset torque, and the intake throttle valve is controlled to open based on the opening degree of the intake throttle valve, and the exhaust throttle valve is controlled to open based on the opening degree of the exhaust throttle valve.

2. The thermal management control method for an engine emission system according to claim 1, characterized in that, The step of controlling the opening or closing of the recirculation control valve and the recirculation bypass control valve based on the temperature of the coolant and the exhaust gas temperature at the inlet of the aftertreatment system includes: When the temperature of the coolant is less than or equal to a first preset temperature, the recirculation control valve is shut off, and the recirculation bypass control valve is opened; or; When the temperature of the coolant is greater than the first preset temperature, and the exhaust gas temperature at the air inlet of the aftertreatment system is consistently lower than the second preset temperature for a duration longer than the first preset duration, the recirculation bypass control valve is opened, and the recirculation control valve is closed; or; When the temperature of the coolant is greater than the first preset temperature, and the temperature of the exhaust gas at the air inlet of the aftertreatment system is continuously lower than the second preset temperature for a duration less than or equal to the first preset duration, the recirculation bypass control valve is controlled to shut off, and the recirculation control valve is controlled to open, with the opening degree of the recirculation control valve being a preset opening degree.

3. The thermal management control method for an engine emission system according to claim 2, characterized in that, The aftertreatment system includes: an oxidation catalytic converter for converting HC and CO in the waste gas and converting NO into NO2; a tightly coupled selective catalytic converter, the inlet of which is connected to the outlet of the exhaust throttle valve and the outlet of which is connected to the inlet of the oxidation catalytic converter; a selective catalytic converter, the inlet of which is connected to the outlet of a particulate matter filter; and a particulate matter filter for capturing carbon particles in the waste gas. The thermal management control method further includes: Based on the exhaust gas flow rate and first exhaust gas temperature at the inlet of the tightly coupled selective catalytic converter, the corresponding first set conversion rate is queried from the preset database. The first feedforward urea injection quantity is calculated based on the content of the first nitrogen oxide in the exhaust gas at the inlet of the tightly coupled selective catalytic converter and the first set conversion rate. The actual conversion rate of the tightly coupled selective catalytic converter is calculated based on the content of the first nitrogen oxide in the exhaust gas at the inlet of the tightly coupled selective catalytic converter and the content of the second nitrogen oxide in the exhaust gas at the inlet of the selective catalytic converter. Calculate the first corrected urea injection amount based on the actual conversion rate and the first set conversion rate; The total urea injection amount of the tightly coupled selective catalytic converter is calculated based on the first feedforward urea injection amount and the first corrected urea injection amount, and the operation of the tightly coupled selective catalytic converter is controlled by the total urea injection amount.

4. A vehicle, characterized in that, include: Engine emission system; A thermal management controller, wherein the thermal management controller is used to execute the thermal management control method of the engine emission system according to any one of claims 1-3; The engine emission system includes: an engine fuel system; An exhaust gas recirculation cooling system includes an exhaust gas recirculation cooler, a recirculation control valve, and a turbocharger. The inlet of the recirculation control valve is connected to the exhaust manifold of the engine, the outlet of the recirculation control valve is connected to the inlet of the exhaust gas recirculation cooler, and the inlet of the turbocharger is connected to the exhaust manifold of the engine. A thermal management system, comprising an intake throttle valve, an exhaust throttle valve, and a recirculation bypass control valve, wherein 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 turbocharger; and ； An aftertreatment system, wherein the air intake of the aftertreatment system is connected to the air outlet of the exhaust throttle valve, and the aftertreatment system is used to treat the exhaust gas discharged from the engine.

5. The vehicle according to claim 4, characterized in that, The post-processing system includes: An oxidation catalytic converter, wherein the oxidation catalytic converter is used to convert HC and CO in waste gas and convert NO into NO2; A catalytic conversion device, wherein the catalytic conversion device is used for the catalytic conversion of nitrogen oxides in waste gas; A particulate matter trap for capturing carbon particles in exhaust gas.

6. The vehicle according to claim 5, characterized in that, The catalytic conversion device includes: A tightly coupled selective catalytic converter, wherein the inlet of the tightly coupled selective catalytic converter is connected to the outlet of the exhaust throttle valve, and the exhaust port of the tightly coupled selective catalytic converter is connected to the inlet of the oxidation catalytic converter; and; A selective catalytic conversion device, wherein the air inlet of the selective catalytic conversion device is connected to the air outlet of the particulate matter trap.

7. The vehicle according to claim 5, characterized in that, The post-processing system also includes: Multiple temperature sensors are used to detect the temperature of the exhaust gas at different stages.

8. The vehicle according to claim 4, characterized in that, The exhaust gas recirculation cooling system also includes: A flow sensor is located downstream of the intake throttle valve, and the flow sensor is used to detect the recirculated air flow rate after the intake throttle valve. An intake air temperature sensor is located downstream of the intake throttle valve and is used to detect the temperature of the recirculated air entering the intake system of the engine. An intake pressure sensor is located downstream of the intake throttle valve and is used to detect the pressure of the recirculated air entering the engine's intake system.

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