EGR valve control method, storage medium, electronic control unit, and automobile

Abstract

An EGR valve control method, comprising: acquiring a mixed intake air mass flow rate of a mixed intake air entering an engine, and acquiring a mixed intake air water content in the mixed intake air; on the basis of the mixed intake air mass flow rate and the mixed intake air water content, determining a characterized saturated water content of the mixed intake air; on the basis of the characterized saturated water content, determining a characterized dew point temperature, and, on the basis of the characterized dew point temperature and a current intake air temperature of the engine, generating an adjustment parameter; and on the basis of the adjustment parameter, adjusting a current EGR rate of an EGR valve, and controlling the EGR valve according to the adjusted current EGR rate. Further disclosed are a storage medium, an electronic control unit, and an automobile.

Description

EGR valve control method, storage medium, electronic control unit and automobile

[0001] Related applications

[0002] The present application claims priority to Chinese Patent Application No. 202410846152.7, filed on June 27, 2024, the contents of which are incorporated herein by reference in their entirety. TECHNICAL FIELD

[0003] The present application relates to the field of exhaust gas recirculation technology, in particular to an EGR valve control method, a storage medium, an electronic control unit and an automobile. BACKGROUND

[0004] At present, the existing exhaust gas recirculation (EGR) supercharged engine can recycle a part of exhaust gas to the engine through the EGR valve, but since the exhaust gas contains water, when the exhaust gas is cooled by the water-cooled intercooler, the water in the exhaust gas will condense to form condensed water, and the exhaust gas will bring these condensed water into the engine, causing the engine to misfire, thereby affecting the user experience. Therefore, how to prevent the condensed water in the exhaust gas from entering the engine is a problem to be solved.

[0005] SUMMARY

[0006] The main purpose of the present application is to provide an EGR valve control method, a storage medium, an electronic control unit and an automobile, which aims to solve the technical problem that the water in the existing exhaust gas forms condensed water after being cooled by the water-cooled intercooler and enters the engine, causing the engine to misfire.

[0007] To achieve the above-mentioned purpose, the present application provides an EGR valve control method, which is applied to an electronic control unit, the electronic control unit is connected with an EGR valve and an engine respectively, and the method comprises:

[0008] Obtaining a mixed intake air mass flow of mixed intake air entering the engine, and obtaining a mixed intake air water content in the mixed intake air;

[0009] Determining a characteristic saturated water content of the mixed intake air based on the mixed intake air mass flow and the mixed intake air water content;

[0010] Determining a characteristic dew point temperature according to the characteristic saturated water content, and generating an adjustment parameter according to the characteristic dew point temperature and a current intake air temperature of the engine;

[0011] Adjusting a current EGR rate of the EGR valve based on the adjustment parameter, and controlling the EGR valve according to the adjusted current EGR rate.

[0012] In an embodiment, the step of determining a representative dew point temperature according to the representative saturated water content comprises:

[0013] determining an initial dew point temperature corresponding to the representative saturated water content, and obtaining a mixed intake air pressure of the mixed intake air;

[0014] determining a representative dew point temperature according to the mixed intake air pressure and the initial dew point temperature.

[0015] In an embodiment, the step of generating an adjustment parameter according to the representative dew point temperature and a current intake air temperature of the engine comprises:

[0016] when the representative dew point temperature is higher than the current intake air temperature of the engine, obtaining a current saturated water content corresponding to the current intake air temperature;

[0017] determining an intake air exhaust water mass ratio corresponding to an intake air exhaust of the engine;

[0018] generating an adjustment parameter based on the current saturated water content, the representative saturated water content, the intake air exhaust water mass ratio, and a mixed intake air mass flow.

[0019] In an embodiment, the step of generating an adjustment parameter based on the current saturated water content, the representative saturated water content, the intake air exhaust water mass ratio, and the mixed intake air mass flow comprises:

[0020] generating an adjustment parameter based on the current saturated water content, the representative saturated water content, the intake air exhaust water mass ratio, and the mixed intake air mass flow through a preset parameter generation formula;

[0021] the preset parameter generation formula is:

[0022] wherein, O is the adjustment parameter, u a is the representative saturated water content, u c is the current saturated water content, ε is the intake air exhaust water mass ratio, and m ath is the mixed intake air mass flow.

[0023] In an embodiment, the step of determining an intake air exhaust water mass ratio corresponding to an intake air exhaust of the engine comprises:

[0024] determining a water mass generated by combustion of the engine in a previous working cycle, an intake air water mass, an intake air exhaust water mass, and a total exhaust mass of total exhaust gas;

[0025] obtaining a total gaseous water mass based on the combustion generated water mass, the intake air water mass, and the intake exhaust gas water mass;

[0026] determining the intake exhaust gas water mass ratio of the reutilization exhaust gas based on the total gaseous water mass and the total exhaust gas mass.

[0027] In an embodiment, the step of obtaining the intake air water mass of the intake air into the engine and the current fuel injection amount of the engine comprises:

[0028] obtaining the intake air water mass of the intake air into the engine and the current fuel injection amount of the engine;

[0029] determining the intake air mass flow of the intake air based on the intake air water mass and the current fuel injection amount;

[0030] determining the intake exhaust gas mass flow of the intake exhaust gas into the engine based on the intake air mass flow and the current EGR rate of the EGR valve;

[0031] determining the mixed intake air mass flow of the mixed intake air into the engine based on the intake air mass flow and the intake exhaust gas mass flow.

[0032] In an embodiment, the step of determining the intake air mass flow of the intake air based on the intake air water mass and the current fuel injection amount comprises:

[0033] determining the required intake dry air mass flow based on the current fuel injection amount, the corresponding excess air coefficient of the engine, and the complete combustion air ratio;

[0034] determining the intake air steam water mass flow based on the intake dry air mass flow and the intake air water mass;

[0035] determining the intake air mass flow of the intake air based on the intake air steam water mass flow and the intake dry air mass flow.

[0036] In an embodiment, the step of obtaining the mixed intake air water mass in the mixed intake air comprises:

[0037] determining the intake exhaust gas steam water mass flow of the intake exhaust gas based on the intake exhaust gas water mass ratio of the intake exhaust gas and the intake exhaust gas mass flow;

[0038] determining the mixed intake air water mass in the mixed intake air based on the intake air steam water mass flow and the intake exhaust gas steam water mass flow.

[0039] In an embodiment, the step of determining the saturation water content of the mixed intake air based on the mixed intake air mass flow and the mixed intake air water content comprises:

[0040] determining a mixed dry intake air mass flow according to the mixed intake air mass flow and the mixed intake air water content;

[0041] determining the saturation water content of the mixed intake air based on the mixed dry intake air mass flow and the mixed intake air water content.

[0042] In addition, to achieve the above object, the present application also provides a storage medium, wherein the storage medium has an EGR valve control program stored thereon, and the EGR valve control program is executed by a processor to implement the EGR valve control method as described above.

[0043] In addition, to achieve the above object, the present application also provides an electronic control unit, wherein the electronic control unit is connected with an EGR valve and an engine respectively, and the electronic control unit comprises:

[0044] a parameter acquisition module, configured to acquire a mixed intake air mass flow of mixed intake air entering the engine, and acquire a mixed intake air water content in the mixed intake air;

[0045] a water content determination module, configured to determine a saturation water content of the mixed intake air based on the mixed intake air mass flow and the mixed intake air water content;

[0046] a parameter determination module, configured to determine a dew point temperature according to the saturation water content, and generate an adjustment parameter according to the dew point temperature and a current intake air temperature of the engine;

[0047] an EGR rate adjustment module, configured to adjust a current EGR rate of the EGR valve based on the adjustment parameter, and control the EGR valve according to the adjusted current EGR rate.

[0048] In addition, to achieve the above object, the present application also provides an automobile, wherein the automobile is provided with an electronic controller unit, and the electronic controller unit comprises a memory, a processor, and an EGR valve control program stored in the memory and capable of running on the processor, and the EGR valve control program is executed by the processor to implement the EGR valve control method as described above.

[0049] The application provides an EGR valve control method, a storage medium, an electronic control unit and a vehicle. The method is applied to the electronic control unit, the electronic control unit is connected with an EGR valve and an engine respectively, and the method comprises the following steps: obtaining a mixed intake air mass flow of mixed intake air entering the engine, and obtaining a mixed intake air water content in the mixed intake air; determining a characteristic saturated water content of the mixed intake air based on the mixed intake air mass flow and the mixed intake air water content; determining a characteristic dew point temperature according to the characteristic saturated water content, and generating an adjustment parameter according to the characteristic dew point temperature and a current intake air temperature of the engine; adjusting a current EGR rate of the EGR valve based on the adjustment parameter, and controlling the EGR valve according to the adjusted current EGR rate. Since the application can determine the characteristic saturated water content of the mixed intake air according to the mixed intake air mass flow of the mixed intake air entering the engine and the mixed intake air water content, then determine the characteristic dew point temperature based on the characteristic saturated water content, and generate the adjustment parameter based on the current intake air temperature of the engine and the characteristic dew point temperature, and finally adjust the current EGR rate of the EGR valve through the adjustment parameter, compared with the existing water in the exhaust gas which is cooled to form condensed water in the water-cooled intercooler and enters the engine, resulting in engine misfire, the application can generate the adjustment parameter according to the current intake air temperature of the engine and the characteristic dew point temperature of the mixed intake air to adjust the current EGR rate, and then control the EGR valve according to the adjusted EGR rate, so that the water content entering the water-cooled intercooler is reduced, thereby reducing the formation of condensed water and reducing the occurrence of engine misfire, and improving the user experience. BRIEF DESCRIPTION OF DRAWINGS

[0050] The drawings incorporated into the specification and forming a part thereof, illustrate embodiments consistent with the application and, together with the description, serve to explain the principles of the application.

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced as follows. Obviously, those drawings can also provide other drawings based on these drawings without creative labor for those skilled in the art.

[0052] Fig. 1 is a schematic diagram of an electronic controller unit structure of a hardware operating environment related to an embodiment of the application;

[0053] Fig. 2 is a schematic diagram of a structure of an existing EGR supercharged engine;

[0054] Fig. 3 is a flowchart of a first embodiment of an EGR valve control method of the application;

[0055] Fig. 4 is a schematic diagram of various gases in the first embodiment of the EGR valve control method of the application;

[0056] Fig. 5 is a flowchart of a second embodiment of the EGR valve control method of the present application;

[0057] Fig. 6 is a flowchart of a third embodiment of the EGR valve control method of the present application;

[0058] Fig. 7 is a structural block diagram of a first embodiment of the electronic control unit of the present application.

[0059] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0060] It should be understood that the specific embodiments described herein merely exemplify the technical solutions of the present application, and are not intended to limit the present application.

[0061] Referring to Fig. 1, Fig. 1 is a structural diagram of an electronic controller unit of a hardware operating environment related to the embodiments of the present application.

[0062] As shown in Fig. 1, the electronic controller unit can be installed on the automobile according to the embodiments of the present application, and the electronic controller unit can include a processor 1001, such as a central processing unit (CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. The communication bus 1002 is used to realize the connection and communication between these components. The user interface 1003 can include a display screen (Display), and the user interface 1003 can also include a standard wired interface and a wireless interface. The wired interface of the user interface 1003 can be a USB interface in the present application. The network interface 1004 can include a standard wired interface and a wireless interface (such as a wireless fidelity (Wi-Fi) interface). The memory 1005 can be a high-speed random access memory (RAM), and can also be a stable memory (NVM), such as a disk memory. The memory 1005 can also be a storage device independent of the aforementioned processor 1001.

[0063] Those skilled in the art can understand that the structure shown in Fig. 1 does not constitute a limitation on the electronic controller unit, and can include more or fewer components than those shown, or combine certain components, or different component arrangements.

[0064] As shown in Fig. 1, the memory 1005, which is a kind of computer storage medium, can include an operating system, a network communication module, a user interface module, and an EGR valve control program.

[0065] In the electronic controller unit shown in FIG. 1, the network interface 1004 is mainly used to connect the background server and communicate data with the background server; the user interface 1003 is mainly used to connect the user equipment; the electronic controller unit calls the EGR valve control program stored in the memory 1005 through the processor 1001, and executes the EGR valve control method provided in the embodiments of the present application.

[0066] It should be noted that at present, the existing exhaust gas recirculation (EGR) supercharged engine can recycle a part of exhaust gas to the engine for reuse through the EGR valve. In order to facilitate understanding, referring to FIG. 2, which is a schematic diagram of the structure of the existing EGR supercharged engine, as shown in FIG. 2, the external air is filtered through the air filter (i.e. air filter in FIG. 2), then transmitted to the supercharger through the vehicle intake pipe for supercharging, and the supercharger transmits the supercharged external air to the intake pipe, while the exhaust gas generated by the engine can be transmitted to the EGR cooler for cooling, and the EGR valve transmits the cooled exhaust gas to the intake pipe as well, and the exhaust gas and the external air are mixed in the intake pipe and transmitted to the water-cooled intercooler through the EGR mixing valve for cooling, wherein the water-cooled intercooler can be provided with cooling liquid, and the mixed exhaust gas and external air can be cooled by the cooling liquid, and then transmitted to the engine through the intake manifold, so as to realize the exhaust gas recirculation.

[0067] However, since the exhaust gas contains water, the water in the exhaust gas will condense to form condensed water after being cooled by the water-cooled intercooler, and the exhaust gas will bring these condensed water into the engine, causing the engine to misfire, thereby affecting the user experience. Therefore, how to prevent the condensed water in the exhaust gas from entering the engine is a problem to be solved.

[0068] In order to solve the above-mentioned defects, the present embodiment provides an EGR valve control method, which can first determine the representative saturated water content of the mixed intake air according to the mixed intake air mass flow and the water content of the mixed intake air entering the engine, then determine the representative dew point temperature based on the representative saturated water content, generate an adjustment parameter based on the current intake air temperature of the engine and the representative dew point temperature, and finally adjust the current EGR rate of the EGR valve through the adjustment parameter. Compared with the existing exhaust gas, the water in the exhaust gas is cooled by the water-cooled intercooler to form condensed water, which enters the engine and causes the engine to misfire, the present embodiment can generate an adjustment parameter according to the current intake air temperature of the engine and the representative dew point temperature of the mixed intake air to adjust the current EGR rate, and then control the EGR valve according to the adjusted EGR rate, so as to reduce the water entering the water-cooled intercooler, thereby reducing the formation of condensed water and reducing the occurrence of engine misfire, and improving the user experience.

[0069] For the convenience of understanding, the EGR valve control method provided by the embodiment of the present application is specifically introduced below in combination with FIG. 3 to FIG. 7.

[0070] Referring to FIG. 3, FIG. 3 is a flowchart of the first embodiment of the EGR valve control method of the present application, and the first embodiment of the EGR valve control method of the present application is proposed, as shown in FIG. 3, in the embodiment, the method is applied to an electronic control unit, and the electronic control unit is connected with an EGR valve and an engine respectively.

[0071] It can be understood that the electronic control unit (ECU) is an electronic device that can be used to control various electronic systems in a vehicle. In the embodiment, the electronic control unit can be used to control the conduction degree of the EGR valve, as shown in FIG. 2. Of course, the conduction degree of the EGR valve can also be controlled by other devices, and the ECU is used to illustrate the embodiment and the following embodiments, but this is not limited.

[0072] The method comprises:

[0073] Step S10: obtaining a mixed intake air mass flow of mixed intake air entering the engine, and obtaining a mixed intake air water content in the mixed intake air.

[0074] It should be understood that the method of the embodiment can be applied to the ECU of the vehicle, and of course, it can also be applied to other devices for controlling the EGR valve in the vehicle, and the embodiment is not limited thereto. The execution subject of the method of the embodiment can use the ECU to illustrate the embodiment and the following embodiments.

[0075] It should be further noted that the mixed intake air can be a gas obtained by mixing external air with reused exhaust gas, and the mixed intake air mass flow can be the mass flow of the mixed intake air entering the engine in this working cycle. Referring to FIG. 4, FIG. 4 is a schematic diagram of various gases in the first embodiment of the EGR valve control method of the present application, as shown in FIG. 4, the external air (i.e. intake air in FIG. 4) passes through the air filter, the vehicle intake pipe and the supercharger in sequence to reach the intake pipe, and then is mixed with part of the reused exhaust gas in the total exhaust gas to obtain the mixed intake air.

[0076] For the convenience of subsequent description, the mixed intake air mass flow is denoted as m ath in the embodiment, and the unit can be kilogram per hour (kg / h); the mixed intake air water content can be the mass flow of water in the mixed intake air in this working cycle, and the mixed intake air water content can be denoted as m wt in the embodiment, and the unit can be kilogram per hour (kg / h). The mixed intake air mass flow m ath and the mixed intake air water content mwt All can be obtained according to the measurement.

[0077] In a specific implementation, the ECU can first obtain the mass flow rate m ath of the mixed intake air and the water content m wt of the mixed intake air.

[0078] Step S20: determining the characteristic saturated water content of the mixed intake air based on the mass flow rate of the mixed intake air and the water content of the mixed intake air.

[0079] It can be understood that the saturated water content is the maximum amount of water vapor that the gas can hold at the current temperature and pressure. When this amount is reached, the gas can be considered saturated, at which time the water vapor and liquid water are in dynamic equilibrium, and no more water can evaporate into the gas. The characteristic saturated water content is the assumed saturated water content in this embodiment, because after obtaining the mixed intake air, it is assumed that the water content in the gas is saturated, and then only the assumed saturated water content is lower than the actual saturated water content, so that no condensate is formed after cooling. Therefore, it is called "characteristic". In order to facilitate subsequent understanding, the characteristic saturated water content is denoted as u a .

[0080] Further, in order to obtain the characteristic saturated water content of the mixed intake air, in this embodiment, the step S20 comprises:

[0081] Step S21: determining the mixed dry intake air mass flow rate based on the mass flow rate of the mixed intake air and the water content of the mixed intake air.

[0082] Step S22: determining the characteristic saturated water content of the mixed intake air based on the mixed dry intake air mass flow rate and the water content of the mixed intake air.

[0083] It should be understood that the mixed dry intake air can be the gas in the mixed intake air without water, and the mixed dry intake air mass flow rate can be the mass flow rate of the gas in the mixed intake air without water. In this embodiment, the mixed dry intake air mass flow rate can be denoted as m atd , which can be expressed in kilograms per hour (kg / h).

[0084] In actual work, the ECU can subtract the mass flow rate of the water in the mixed intake air from the mass flow rate m ath of the mixed intake air to obtain the mixed dry intake air mass flow rate m atd , i.e., m atd =m ath -m wt ; in this embodiment, the mixed dry intake air mass flow rate m atdThen, the mass flow rate of water can be divided by the mass flow rate of the mixed dry intake air to obtain a saturation water content u a That is

[0085] Step S30: determining a dew point temperature according to the saturation water content, and generating an adjustment parameter according to the dew point temperature and a current intake air temperature of the engine.

[0086] It is understood that the dew point temperature is the temperature at which the water vapor content in the gas reaches saturation. That is, when the water vapor content in the gas increases to a maximum value at a certain temperature, further increase in the water vapor content will cause the water vapor to begin to condense into liquid water. The above-mentioned dew point temperature is also the assumed dew point temperature in this embodiment, because the saturation water content is assumed when determining the saturation water content, and therefore the dew point temperature determined according to the saturation water content is also the assumed dew point temperature. For the convenience of subsequent description, the saturation water content is denoted as T b .

[0087] It is emphasized that in order to determine the dew point temperature, the step of determining the dew point temperature according to the saturation water content includes:

[0088] Step S31: determining an initial dew point temperature corresponding to the saturation water content, and obtaining a mixed intake air pressure of the mixed intake air.

[0089] Step S32: determining a dew point temperature according to the mixed intake air pressure and the initial dew point temperature.

[0090] It is noted that because the above-mentioned mixed intake air is at atmospheric pressure before entering the water-cooled intercooler, and the pressure after the output of the water-cooled intercooler is not atmospheric pressure, but the dew point temperature is closely related to the pressure, and therefore the above-mentioned initial dew point temperature can be the dew point temperature of the mixed intake air at atmospheric pressure, which can be obtained according to a lookup table. That is, a mapping relationship table of the dew point temperature corresponding to different pressures and different saturation water contents can be pre-stored in the ECU, and after the ECU obtains the saturation water content T b , the mapping relationship table can be queried to obtain the dew point temperature corresponding to the saturation water content T b at atmospheric pressure as the initial dew point temperature, denoted as T a .

[0091] It is understood that the above-mentioned mixed intake air pressure can be the pressure of the mixed gas transmitted to the intake manifold after being cooled by the water-cooled intercooler in this working cycle, which can be denoted as p b . And in order to obtain the mixed intake air pressure p bAs shown in FIG. 4, the embodiment can be provided with a temperature sensor and a pressure sensor (i.e. the temperature and pressure sensors in FIG. 4) in the intake manifold, and the temperature sensor and the pressure sensor are connected with the ECU, and then the above-mentioned mixed intake pressure p b .

[0092] It should be understood that the ECU can also store a dew point temperature conversion table under different air pressures, i.e. a conversion table corresponding to the dew point temperature under different air pressures, which can also be obtained in advance according to tests. Then after obtaining the initial dew point temperature T a and the mixed intake pressure p b , the initial dew point temperature T a under atmospheric pressure can be converted into the dew point temperature under the mixed intake pressure p b according to the dew point temperature conversion table, as the above-mentioned characteristic dew point temperature T b .

[0093] The above-mentioned adjustment parameter can be a parameter for adjusting the conduction degree of the EGR valve. After obtaining the characteristic dew point temperature T b , the current intake temperature of the mixed intake into the engine can be obtained by the temperature sensor at the intake manifold, denoted as T c . At this time, the characteristic dew point temperature T b and the current intake temperature T c can be compared, if the characteristic dew point temperature T b is less than or equal to the current intake temperature T c , it can be indicated that there is no condensed water at this time, and the current EGR rate of the EGR valve does not need to be adjusted; if the characteristic dew point temperature T b is greater than the current intake temperature T c , it can be indicated that there can be condensed water at this time, and then the adjustment parameter needs to be generated according to the characteristic dew point temperature T b and the current intake temperature T c .

[0094] Step S40: adjusting the current EGR rate of the EGR valve based on the adjustment parameter, and controlling the EGR valve according to the adjusted current EGR rate.

[0095] It is easy to understand that the current EGR rate can be the current opening degree of the EGR valve, since the ECU can control the conduction degree of the EGR valve in the embodiment, and then the ECU can store the current EGR rate of the EGR valve, and then adjust the current EGR rate according to the generated adjustment parameter, so as to obtain the conduction degree of the EGR valve after adjustment (i.e. the adjusted EGR rate), and then the ECU can adjust the EGR valve to the adjusted EGR rate, so that the water in the water-cooled intercooler is reduced, the formation of condensed water is reduced, the occurrence of engine misfire is reduced, and the user experience is improved.

[0096] In the embodiment, the ECU can first determine the representative saturated water content of the mixed intake air according to the mixed intake air mass flow and the water content of the mixed intake air into the engine, then determine the representative dew point temperature based on the representative saturated water content, and generate an adjustment parameter based on the current intake air temperature of the engine and the representative dew point temperature, and finally adjust the current EGR rate of the EGR valve through the adjustment parameter. Compared with the existing water in the exhaust gas forming condensed water after being cooled by the water-cooled intercooler and entering the engine, causing engine misfire, the embodiment can generate an adjustment parameter according to the current intake air temperature of the engine and the representative dew point temperature of the mixed intake air to adjust the current EGR rate, and then control the EGR valve according to the adjusted EGR rate, so that the water in the water-cooled intercooler is reduced, the formation of condensed water is reduced, the occurrence of engine misfire is reduced, and the user experience is improved.

[0097] Referring to FIG. 5, FIG. 5 is a flowchart of the second embodiment of the EGR valve control method of the present application. Based on the first embodiment, the second embodiment of the EGR valve control method of the present application is proposed.

[0098] In order to generate the adjustment parameter, as shown in FIG. 5, in the embodiment, the step of generating the adjustment parameter according to the representative dew point temperature and the current intake air temperature of the engine includes:

[0099] Step S33: When the representative dew point temperature is higher than the current intake air temperature of the engine, the current saturated water content corresponding to the current intake air temperature is obtained.

[0100] It should be noted that the current saturated water content can be the saturated water content of the gas at the current intake air temperature T c When the ECU determines that the representative dew point temperature T b is less than or equal to the current intake air temperature T c , it indicates that there is no condensed water at this time, and the current EGR rate of the EGR valve does not need to be adjusted; if the representative dew point temperature T b is greater than the current intake air temperature T c, which indicates that there is condensate water at this time, and then the ECU can determine the current intake air temperature T c as the dew point temperature according to the mapping relationship table above, and the corresponding saturated water content under the pressure of the mixed intake air pressure p b as the current saturated water content, denoted as u c .

[0101] Step S34: Determine the intake exhaust water content ratio corresponding to the intake exhaust of the engine.

[0102] It can be understood that the intake exhaust is the reused exhaust (i.e., the reused exhaust in FIG. 4), and the intake exhaust water content ratio can be the ratio of the total exhaust gas water mass to the total exhaust mass generated by the engine in the last working cycle. That is, after measuring the total exhaust mass generated and the mass of gaseous water in the total exhaust, the intake exhaust water content ratio can be obtained. For the convenience of subsequent description, the intake exhaust water content ratio is denoted as ε.

[0103] Further, in order to obtain the intake exhaust water content ratio ε, in the embodiment, the step S34 comprises:

[0104] Step S341: Determine the combustion generated water mass, intake air water mass, intake exhaust water mass, and total exhaust mass of the total exhaust generated by the engine in the last working cycle.

[0105] It should be understood that the combustion generated water mass can be the water mass generated by the engine in the last working cycle by burning pure dry (i.e., without water) air, which can be calculated according to the mass of fuel consumed by the engine in the last working cycle, i.e., according to the mass of fuel consumed, the molecular formula of the fuel, the molar mass, and the mass of pure dry (i.e., without water) air required for combustion per kilogram.

[0106] Specifically, taking gasoline as an example, its main component is heptane, the molecular formula is C7H 14 , the molar mass is 98 g / mol, the mass of pure dry air required for combustion per kilogram is 14.7 kilograms, and then the combustion generated water mass generated by combustion can be obtained according to how much gasoline is consumed.

[0107] The intake air water mass can be the mass of water contained in the intake air into the engine in the last working cycle, which can be measured by a humidity sensor. Specifically, as shown in FIG. 4, the embodiment can also be installed with a temperature sensor, a humidity sensor, and a pressure sensor in the vehicle intake pipe, which are connected with the ECU, and then the mass of water contained in the intake air into the engine can be measured by the humidity sensor therein as the intake air water mass.

[0108] The intake exhaust water mass can be how much mass of water contained in the reutilization exhaust gas in the previous working cycle. Specifically, the mass of water in the total exhaust gas generated in the previous working cycle is multiplied by the EGR rate corresponding to the EGR valve in the previous working cycle to obtain the intake exhaust water mass.

[0109] The total exhaust gas can be the total exhaust gas generated by the engine in a working cycle, and the total exhaust gas mass can be the mass of the total exhaust gas generated by the engine in the previous working cycle.

[0110] Step S342: Obtain the total gaseous water mass based on the combustion generated water mass, the intake air water mass, and the intake exhaust water mass.

[0111] It should also be understood that the total gaseous water mass can be the mass of water contained in the total exhaust gas generated in the current working cycle. It can be obtained by summing the combustion generated water mass, the intake air water mass, and the intake exhaust water mass. For the convenience of subsequent description, the total gaseous water mass can be denoted as m w .

[0112] Step S343: Determine the intake exhaust water mass proportion corresponding to the reutilization exhaust gas based on the total gaseous water mass and the total exhaust gas mass.

[0113] In a specific implementation, if the total exhaust gas mass is denoted as m et , after obtaining the total gaseous water mass m w and the total exhaust gas mass m et , the total gaseous water mass m w can be divided by the total exhaust gas mass m et , that is, the intake exhaust water mass proportion ε can be obtained.

[0114] Step S35: Generate an adjustment parameter based on the current saturation water content, the representative saturation water content, the intake exhaust water mass proportion, and the mixed intake mass flow.

[0115] It should be noted that after obtaining the intake exhaust water mass proportion ε, the adjustment parameter can be calculated based on the current saturation water content u c , the representative saturation water content T b , the intake exhaust water mass proportion ε, and the mixed intake mass flow m ath .

[0116] Specifically, the above step S35 includes:

[0117] The preset parameter generation formula is generated based on the current saturation moisture content, the characteristic saturation moisture content, the intake air exhaust gas moisture mass ratio, and the mixed intake air mass flow;

[0118] The preset parameter generation formula is:

[0119] Wherein, O is the adjustment parameter, u a is the characteristic saturation moisture content, u c is the current saturation moisture content, and ε is the intake air exhaust gas moisture mass ratio, m ath is the mixed intake air mass flow.

[0120] In a specific implementation, after obtaining the adjustment parameter, the current EGR rate can be adjusted based on the adjustment parameter, that is, the adjusted current EGR rate = current EGR rate - O.

[0121] Referring to FIG. 6, FIG. 6 is a flowchart of a third embodiment of the EGR valve control method of the application. Based on the above embodiments, the third embodiment of the EGR valve control method of the application is proposed.

[0122] As shown in FIG. 6, in order to obtain the mixed intake air mass flow m ath In this embodiment, the step of obtaining the mixed intake air mass flow of the mixed intake air entering the engine includes:

[0123] Step S11: obtaining the intake air moisture content of intake air entering the engine and the current fuel injection amount of the engine.

[0124] It should be noted that the intake air moisture content can be the amount of water vapor contained in the intake air entering the engine in this working cycle, which can also be obtained by collecting the temperature sensor at the vehicle intake pipe in FIG. 4. In this embodiment, the above intake air moisture content can be denoted as u, with the unit of grams per kilogram (g / kg).

[0125] It can be understood that the current fuel injection amount of the engine can be the mass of fuel that needs to be injected by the engine in this working cycle. The ECU can query the corresponding fuel injection amount mapping relationship table according to the engine speed, throttle opening and other parameters to obtain it. The specific fuel injection amount mapping relationship table is not limited in this embodiment. In order to facilitate subsequent description, the current fuel injection amount can be denoted as M f .

[0126] Step S12: determining the intake air mass flow of the intake air based on the intake air moisture content and the current fuel injection amount.

[0127] It should be understood that the above-mentioned intake air mass flow rate can be the mass flow rate of intake air entering the engine in this working cycle, which can be denoted as m. aw The unit can be kilograms per hour (kg / h).

[0128] Specifically, in order to obtain the intake air mass flow rate m aw Step S12 above includes:

[0129] Step S121: Determine the required intake dry air mass flow rate based on the current fuel injection quantity, the excess air coefficient corresponding to the engine, and the complete combustion air ratio.

[0130] The aforementioned intake dry air mass flow rate can be the current fuel injection quantity M in this working cycle. f The mass flow rate of pure dry (i.e., moisture-free) air required for combustion can be denoted as m. a The unit can be kilograms per hour (kg / h), which can be calculated from the mass of pure dry (i.e., moisture-free) air required to burn one kilogram (i.e., 14.7 above) and the excess air coefficient. The excess air coefficient is the ratio of the actual amount of dry air supplied during combustion to the theoretical amount of air (i.e., the amount of air required for complete combustion). This coefficient can be used to describe the difference between actual combustion conditions and ideal complete combustion conditions. In this embodiment, the excess air coefficient can be denoted as λ, and then m... a =14.7*λ*M f .

[0131] Step S122: Determine the intake air steam-water mass flow rate based on the intake dry air mass flow rate and the intake air moisture content.

[0132] The aforementioned intake air steam-water mass flow rate can be considered as the mass flow rate of steam-water in the intake air during this working cycle. Let m be the intake air steam-water mass flow rate. w Then m w =m a *u / 1000.

[0133] Step S123: Determine the intake air mass flow rate based on the intake air vapor water mass flow rate and the intake air dry mass flow rate.

[0134] Obtain the mass flow rate m of intake air vapor water w and intake dry air mass flow rate (m) a Then, the mass flow rate m of the intake air vapor water can be calculated. w With intake dry air mass flow rate m a The sum of these values ​​is taken as the above intake air mass flow rate m. aw That is, m aw =ma +m w .

[0135] Step S13: determining an intake exhaust gas mass flow of intake exhaust gas into the engine according to the intake air mass flow and a current EGR rate of the EGR valve.

[0136] It should be understood that the intake exhaust gas mass flow can be a mass flow of the reused exhaust gas into the engine in the current working cycle, denoted as m wegr , and the unit can be kilogram per hour (kg / h). egr After obtaining the intake air mass flow m aw , the ECU can obtain the intake exhaust gas mass flow m aw according to the product of the intake air mass flow m egr and the current EGR rate.

[0137] Step S14: determining a mixed intake mass flow of mixed intake into the engine based on the intake air mass flow and the intake exhaust gas mass flow.

[0138] In a specific implementation, after obtaining the intake air mass flow m aw and the intake exhaust gas mass flow m egr , the sum of the intake air mass flow m aw and the intake exhaust gas mass flow m egr can be taken as the mixed intake mass flow m ath , i.e., m ath = m aw + m egr .

[0139] Further, in order to obtain the mixed intake water content m wt , in the embodiment, the step of obtaining the mixed intake water content in the mixed intake includes:

[0140] Step S15: determining an intake exhaust gas steam water mass flow of the intake exhaust gas according to the intake exhaust gas water content mass ratio and the intake exhaust gas mass flow.

[0141] It should be understood that the intake exhaust gas steam water mass flow can be a mass flow of steam water in the reused exhaust gas into the engine in the current working cycle, denoted as m wegr , and the unit can be kilogram per hour (kg / h).

[0142] Further, after obtaining the intake exhaust gas water content mass ratio ε and the intake exhaust gas mass flow m egr , the product of the intake exhaust gas mass flow m egr and the intake exhaust gas water content mass ratio ε can be taken as the intake exhaust gas steam water mass flow mwegr i.e. m wegr = m egr * ε.

[0143] Step S16: determining the mixed intake air moisture content in the mixed intake air based on the intake air steam water mass flow and the intake exhaust steam water mass flow.

[0144] In a specific implementation, when the intake air steam water mass flow m w and the intake exhaust steam water mass flow m wegr are obtained, the sum of the intake air steam water mass flow m w and the intake exhaust steam water mass flow m wegr can be taken as the mixed intake air moisture content m wt i.e. m wt = m w + m wegr .

[0145] In addition, the embodiment of the present application further provides a storage medium, wherein the storage medium stores an EGR valve control program, and the EGR valve control program is executed by a processor to implement the EGR valve control method as described above.

[0146] In addition, referring to FIG. 7, which is a structural block diagram of the first embodiment of the electronic control unit of the present application, as shown in FIG. 7, the embodiment of the present application further provides an electronic control unit, which is connected with an EGR valve and an engine respectively, and the electronic control unit comprises:

[0147] a parameter acquisition module 701, configured to acquire a mixed intake air mass flow of mixed intake air entering the engine, and acquire a mixed intake air moisture content in the mixed intake air;

[0148] a moisture content determination module 702, configured to determine a representative saturated moisture content of the mixed intake air based on the mixed intake air mass flow and the mixed intake air moisture content;

[0149] a parameter determination module 703, configured to determine a representative dew point temperature according to the representative saturated moisture content, and generate an adjustment parameter according to the representative dew point temperature and a current intake air temperature of the engine;

[0150] an EGR rate adjustment module 704, configured to adjust a current EGR rate of the EGR valve based on the adjustment parameter, and control the EGR valve according to the adjusted current EGR rate.

[0151] In the embodiment, the ECU can first determine the representative saturated water content of the mixed intake air according to the mixed intake air mass flow and the mixed intake air water content of the mixed intake air into the engine, then determine the representative dew point temperature based on the representative saturated water content, and generate the adjustment parameter based on the current intake air temperature of the engine and the representative dew point temperature, and finally adjust the current EGR rate of the EGR valve through the adjustment parameter. Compared with the existing water in the exhaust gas which forms condensed water after being cooled by the water-cooled intercooler and enters the engine, causing misfire of the engine, the embodiment can generate the adjustment parameter to adjust the current EGR rate according to the current intake air temperature of the engine and the representative dew point temperature of the mixed intake air, and control the EGR valve according to the adjusted EGR rate, so as to reduce the water entering the water-cooled intercooler, thereby reducing the formation of condensed water and reducing the occurrence of engine misfire, and improving the user experience.

[0152] As an implementation form, the water content determination module 702 is further configured to determine a mixed dry intake air mass flow according to the mixed intake air mass flow and the mixed intake air water content; and determine the representative saturated water content of the mixed intake air based on the mixed dry intake air mass flow and the mixed intake air water content.

[0153] As an implementation form, the parameter determination module 703 is further configured to determine an initial dew point temperature corresponding to the representative saturated water content, and obtain a mixed intake air pressure of the mixed intake air; and determine the representative dew point temperature according to the mixed intake air pressure and the initial dew point temperature.

[0154] Based on the above-mentioned first embodiment of the electronic control unit, the second embodiment of the electronic control unit is proposed.

[0155] In the embodiment, the parameter determination module 703 is further configured to, when the representative dew point temperature is higher than the current intake air temperature of the engine, obtain a current saturated water content corresponding to the current intake air temperature; determine an intake air exhaust gas water mass ratio corresponding to intake air exhaust gas of the engine; and generate the adjustment parameter based on the current saturated water content, the representative saturated water content, the intake air exhaust gas water mass ratio, and the mixed intake air mass flow.

[0156] As an implementation form, the parameter determination module 703 is further configured to generate the adjustment parameter based on the current saturated water content, the representative saturated water content, the intake air exhaust gas water mass ratio, and the mixed intake air mass flow through a preset parameter generation formula; and the preset parameter generation formula is: wherein, O is the adjustment parameter, u a is the representative saturated water content, u c is the current saturated water content, ε is the intake air exhaust gas water mass ratio, and m ath is the mixed intake air mass flow.

[0157] As an implementation form, the parameter determination module 703 is further configured to determine a combustion generated water mass, intake air water mass, intake exhaust gas water mass, and total exhaust gas mass of the total exhaust gas generated in a previous working cycle of the engine; obtain a total gaseous water mass based on the combustion generated water mass, the intake air water mass, and the intake exhaust gas water mass; and determine the intake exhaust gas water content proportion corresponding to the recycled exhaust gas according to the total gaseous water mass and the total exhaust gas mass.

[0158] Based on the above-mentioned embodiments of the electronic control unit, a third embodiment of the electronic control unit is provided.

[0159] In the embodiment, the parameter acquisition module 701 is further configured to acquire an intake air water content of intake air entering the engine and a current fuel injection amount of the engine; determine an intake air mass flow of the intake air based on the intake air water content and the current fuel injection amount; determine an intake exhaust gas mass flow of intake exhaust gas entering the engine according to the intake air mass flow and a current EGR rate of the EGR valve; and determine a mixed intake air mass flow of mixed intake air entering the engine based on the intake air mass flow and the intake exhaust gas mass flow.

[0160] As an implementation form, the parameter acquisition module 701 is further configured to determine a required intake dry air mass flow based on the current fuel injection amount, a corresponding excess air coefficient of the engine, and a complete combustion air proportion; determine an intake air steam water mass flow according to the intake dry air mass flow and the intake air water content; and determine the intake air mass flow of the intake air based on the intake air steam water mass flow and the intake dry air mass flow.

[0161] As an implementation form, the parameter acquisition module 701 is further configured to determine an intake exhaust gas steam water mass flow of the intake exhaust gas according to an intake exhaust gas water content proportion of the intake exhaust gas and the intake exhaust gas mass flow; and determine a mixed intake air water content in the mixed intake air based on the intake air steam water mass flow and the intake exhaust gas steam water mass flow.

[0162] Other embodiments or specific implementation forms of the electronic control unit described in the present application can refer to the above-mentioned method embodiments, and will not be described here.

[0163] It should be noted that, in this document, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element preceded by "comprises... a" does not, without more constraints, foreclose the existence of additional identical elements in the process, method, article, or apparatus that comprises the recited element.

[0164] The above-mentioned sequence numbers of embodiments of the present application are only for description, and do not represent advantages or disadvantages of the embodiments.

[0165] From the above description of the embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be realized by means of software and a general hardware platform, and of course, can also be realized by hardware, but in many cases, the former is a better embodiment. Based on such understanding, the technical solutions of the present application can be embodied in the form of a software product in essence or in the form of a part of the prior art that makes a contribution. The computer software product is stored in a storage medium (such as a read-only memory (ROM) / random access memory (RAM), a magnetic disk, or an optical disk) and includes a plurality of instructions for causing a terminal device (which can be a mobile phone, a computer, a server, or a network device) to execute the methods described in the embodiments of the present application.

[0166] The above is only an optional embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied to other related technical fields, is also included in the patent protection scope of the present application.

Claims

1. An EGR valve control method, wherein, The method is applied to an electronic control unit, which is connected to both the EGR valve and the engine, and the method includes: Obtain the mass flow rate of the mixed intake air entering the engine, and obtain the water content of the mixed intake air; The characterization saturated water content of the mixed intake air is determined based on the mixed intake air mass flow rate and the mixed intake air water content. The characterization dew point temperature is determined based on the characterization saturated water content, and adjustment parameters are generated based on the characterization dew point temperature and the current intake air temperature of the engine. The current EGR rate of the EGR valve is adjusted based on the adjustment parameters, and the EGR valve is controlled according to the adjusted current EGR rate.

2. The method as described in claim 1, wherein, The step of determining the dew point temperature based on the characterized saturated water content includes: Determine the initial dew point temperature corresponding to the characterized saturated water content, and obtain the mixed intake pressure of the mixed intake air; The dew point temperature is determined based on the mixed intake pressure and the initial dew point temperature.

3. The method as described in claim 1, wherein, The step of generating adjustment parameters based on the dew point temperature and the current intake air temperature of the engine includes: When the dew point temperature is higher than the current intake air temperature of the engine, the current saturated water content corresponding to the current intake air temperature is obtained; Determine the water content ratio of the intake and exhaust gases entering the engine; Adjustment parameters are generated based on the current saturated water content, the characterizing saturated water content, the water content ratio of the intake and exhaust gases, and the mixed intake gas mass flow rate.

4. The method of claim 3, wherein, The step of generating adjustment parameters based on the current saturated water content, the characterizing saturated water content, the water content ratio of the intake and exhaust gases, and the mixed intake gas mass flow rate includes: Adjustment parameters are generated by a formula based on the current saturated water content, the characterizing saturated water content, the water content ratio of the intake and exhaust gases, and the mass flow rate of the mixed intake gases, using preset parameters. The formula for generating the preset parameters is: Where O is the adjustment parameter, u a u represents the saturated water content. c The current saturated water content is ε, where ε is the water content ratio of the intake and exhaust gases, and m is the total water content. ath The mass flow rate of the mixed intake air is denoted as .

5. The method of claim 3, wherein, The step of determining the water content ratio of the intake and exhaust gases entering the engine includes: Determine the mass of water generated by combustion in the engine in the previous working cycle, the mass of water in the intake air, the mass of water in the intake exhaust gas, and the total mass of exhaust gas generated. The total mass of gaseous water is obtained based on the mass of water generated during combustion, the mass of water in the intake air, and the mass of water in the intake exhaust gas. The water content ratio of the intake exhaust gas corresponding to the reused exhaust gas is determined based on the total mass of gaseous water and the total mass of exhaust gas.

6. The method of claim 3, wherein, The step of obtaining the mass flow rate of the mixed intake air entering the engine includes: The moisture content of the intake air entering the engine and the current fuel injection quantity of the engine are obtained. The intake air mass flow rate is determined based on the moisture content of the intake air and the current fuel injection quantity. The intake exhaust gas mass flow rate entering the engine is determined based on the intake air mass flow rate and the current EGR rate of the EGR valve. The mixed intake air mass flow rate entering the engine is determined based on the intake air mass flow rate and the intake exhaust gas mass flow rate.

7. The method of claim 6, wherein, The step of determining the intake air mass flow rate based on the intake air moisture content and the current fuel injection quantity includes: The required intake dry air mass flow rate is determined based on the current fuel injection quantity, the excess air coefficient corresponding to the engine, and the proportion of complete combustion air. The intake air steam-water mass flow rate is determined based on the intake dry air mass flow rate and the intake air moisture content. The intake air mass flow rate is determined based on the intake air vapor-water mass flow rate and the intake air dry mass flow rate.

8. The method of claim 7, wherein, The step of obtaining the water content of the mixed intake air includes: The mass flow rate of the steam-water mixture in the intake exhaust gas is determined based on the water content ratio of the intake exhaust gas and the mass flow rate of the intake exhaust gas. The water content of the mixed intake air is determined based on the mass flow rate of the intake air vapor water and the mass flow rate of the intake exhaust gas vapor water.

9. The method of claim 1, wherein, The step of determining the characterizing saturated moisture content of the mixed intake air based on the mixed intake air mass flow rate and the mixed intake air moisture content includes: The mixed dry intake air mass flow rate is determined based on the mixed intake air mass flow rate and the mixed intake air moisture content; The characterization saturated water content of the mixed intake air is determined based on the mass flow rate of the mixed dry intake air and the water content of the mixed intake air.

10. A storage medium, wherein, The storage medium stores an EGR valve control program, which, when executed by a processor, implements the EGR valve control method as described in any one of claims 1 to 9.

11. An electronic control unit, wherein, The electronic control unit is connected to both the EGR valve and the engine. The electronic control unit includes: The parameter acquisition module is used to acquire the mass flow rate of the mixed intake air entering the engine and to acquire the water content of the mixed intake air. A moisture content determination module is used to determine the characterized saturated moisture content of the mixed intake air based on the mixed intake air mass flow rate and the mixed intake air moisture content; The parameter determination module is used to determine the characterization dew point temperature based on the characterization saturated water content, and to generate adjustment parameters based on the characterization dew point temperature and the current intake air temperature of the engine. The EGR rate adjustment module is used to adjust the current EGR rate of the EGR valve based on the adjustment parameters, and to control the EGR valve according to the adjusted current EGR rate.

12. A type of automobile, wherein, The vehicle is equipped with an electronic controller unit, which includes a memory, a processor, and an EGR valve control program stored in the memory and executable on the processor. When the EGR valve control program is executed by the processor, it implements the EGR valve control method as described in any one of claims 1 to 9.

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