Engine fuel combustion control method and device based on high-pressure gas supply system

Abstract

The invention discloses an engine fuel combustion control method and device based on a high-pressure gas supply system, and relates to the field of engine combustion control. The method comprises the following steps: acquiring load state data of an engine within a first duration; based on the load state data, whether the engine meets the condition of switching to a lean burn mode or not is judged, and when the switching condition is met, the engine is controlled to be switched to the lean burn mode; on the basis of the load fluctuation condition of the engine, the energy compensation demand change condition of the engine within the second duration after switching is predicted, and compensation information is obtained; and on the basis of the compensation information, configuration information of the high-pressure gas supply system and the engine within the second duration is determined. According to the scheme provided by the embodiment of the invention, the combustion stability in a lean combustion mode can be improved, and the engine performance is improved.

Description

Technical Field

[0001] The present application relates to the field of engine combustion control, and in particular to a method and device for controlling engine fuel combustion based on a high-pressure air supply system. Background Art

[0002] With the advancement of precision injection technology for internal combustion engines, significant progress has been made in the technology of vehicles fueled by liquefied natural gas, liquid hydrogen, liquid ammonia, and methanol. In these high-pressure fuel systems, lean burn mode has attracted widespread attention due to its higher thermal efficiency and lower nitrogen oxide emissions. Existing technologies trigger lean burn mode when power falls below a fixed value. Once in lean burn mode, a pre-set fixed compensation value is often used to adjust power parameters such as injection quantity and ignition advance angle.

[0003] However, it is difficult to respond to load changes in a timely and accurate manner using a fixed compensation value, which reduces the combustion stability in the lean burn mode and further affects the engine performance.

[0004] Therefore, how to overcome the above-mentioned technical problems and defects becomes a key issue that needs to be solved. Summary of the Invention

[0005] In order to solve the above technical problems, the present application provides an engine fuel combustion control based on a high-pressure air supply system, which can improve combustion stability in a lean combustion mode and improve engine performance.

[0006] According to one aspect of the present application, a method for controlling engine fuel combustion based on a high-pressure air supply system is provided, the method comprising:

[0007] Collecting engine load state data within a first period of time;

[0008] determining, based on the load state data, whether the engine satisfies a condition for switching to a lean burn mode, and controlling the engine to switch to the lean burn mode when the switching condition is satisfied;

[0009] Based on the load fluctuation of the engine, predicting the change of the energy compensation demand of the engine within a second period after the switching, and obtaining compensation information;

[0010] Based on the compensation information, configuration information of the high-pressure air supply system and the engine within a second time period is determined.

[0011] In the above solution, the method further includes:

[0012] Based on the external environmental information, determining the degree of influence of the external temperature and pressure on the engine load threshold, and obtaining a first environmental correction coefficient; the first environmental correction coefficient includes a first temperature correction coefficient and a first pressure correction coefficient;

[0013] The determining, based on the load state data, whether the engine meets a condition for switching to the lean burn mode includes:

[0014] determining a current load rate of the engine based on the load state data;

[0015] Correcting the preset load interval value range based on the first environmental correction coefficient to obtain a corrected load interval;

[0016] Based on the position of the engine load rate in the correction load range, it is determined whether the engine meets the conditions for switching to the lean burn mode.

[0017] In the above solution, the division point of the modified load range includes a first threshold and a second threshold, and the first threshold is less than the second threshold; and determining whether the engine meets the conditions for switching to the lean burn mode based on the position of the engine load rate in the modified load range includes:

[0018] When the engine load rate is lower than a first threshold and the coolant temperature is higher than a water temperature threshold, determining that the engine meets the conditions for switching to the lean burn mode;

[0019] When the engine load rate is between a first threshold and a second threshold, it is determined that the engine meets the condition for switching to the lean burn mode.

[0020] In the above solution, the prediction of the change in the energy compensation demand of the engine within the second period after the switching based on the load fluctuation of the engine to obtain the compensation information includes:

[0021] Determining load variation characteristics of the engine based on the load variation of the engine; the load variation characteristics include load variation rate, load fluctuation amplitude, and load fluctuation frequency;

[0022] Based on the load variation characteristics, predicting a load variation of the engine along a time axis within a second time period to obtain load fluctuation information;

[0023] Based on the load fluctuation information and pre-configured engineering constraints, an MPC algorithm is used to determine the jet engineering parameter compensation requirements of the engine within a second time period to obtain compensation information; the objective function of the MPC algorithm is to minimize power error.

[0024] In the above solution, the configuration information includes gas injection configuration information, ignition configuration information and air-fuel ratio configuration information; the method further includes:

[0025] Based on the configuration information, an adjustment target of the operating parameter of the high-pressure gas supply system is determined in at least one of the following ways:

[0026] determining a target injection pulse width and a target injection pressure of the gas supply system based on the gas injection configuration information;

[0027] determining a target ignition advance angle of the engine based on the ignition configuration information;

[0028] Based on the air-fuel ratio configuration information, a target air-fuel ratio of the engine is determined.

[0029] In the above solution, the high-pressure gas supply system further includes an EGR unit, and the EGR unit includes a gas return control valve; after switching to the lean gas mode, the method further includes:

[0030] According to a preset feedback sampling frequency, the actual injection amount of the fuel gas after compensation based on the configuration information is collected;

[0031] determining an exhaust gas recovery ratio for a next feedback sampling period based on a difference between the actual injection amount and the reference injection amount;

[0032] Based on the exhaust gas recovery ratio, the opening of the fuel gas return control valve in the EGR unit is adjusted.

[0033] In the above solution, the method further includes:

[0034] Based on the external environmental information, determining the degree of influence of the external temperature and pressure on the engine engineering parameters, and obtaining a second environmental correction coefficient; the second environmental correction coefficient includes a second temperature correction coefficient and a second pressure correction coefficient;

[0035] The adjusting the opening of the gas return control valve in the EGR unit based on the exhaust gas recovery ratio includes:

[0036] Correcting the exhaust gas recovery ratio based on the second environmental correction coefficient to obtain a corrected exhaust gas recovery ratio;

[0037] Based on the corrected exhaust gas recovery ratio, the opening of the fuel gas return control valve in the EGR unit is adjusted.

[0038] In the above solution, in the lean burn mode, the method further includes:

[0039] Based on the real-time collected load data, determining whether the engine has a sudden load change;

[0040] When a sudden load change occurs in the engine, a torque deviation is determined based on the load change value;

[0041] generating a vector control instruction for performing PI control on an electrical vector of the engine based on the torque deviation; the electrical vector includes a current vector and a voltage vector;

[0042] In response to the vector control command, torque compensation is performed on the engine.

[0043] In the above solution, generating a vector control instruction for performing PI control on the electrical vector of the engine based on the torque deviation includes:

[0044] determining a PI control increment based on the torque deviation;

[0045] Mapping the PI control increment to an electrical vector to obtain electrical vector compensation information;

[0046] The vector control instruction is generated based on the electrical vector compensation information.

[0047] According to a second aspect of the present application, there is provided an engine fuel combustion control device based on a high-pressure air supply system, the device comprising:

[0048] A collection unit, configured to collect load state data of the engine within a first period of time;

[0049] a control unit, configured to determine, based on the load state data, whether the engine satisfies a condition for switching to a lean burn mode, and control the engine to switch to the lean burn mode when the switching condition is satisfied;

[0050] A first processing unit is configured to predict, based on the load fluctuation of the engine, a change in energy compensation demand of the engine within a second period after the switching, and obtain compensation information;

[0051] The second processing unit is configured to determine configuration information of the high-pressure air supply system and the engine within a second time period based on the compensation information.

[0052] The engine fuel combustion control method and device based on the high-pressure air supply system provided in the present application can detect the engine load changes in real time by collecting load status data in real time, so that the combustion mode can be switched in time when the switching conditions are met, thereby improving the response speed and stability of the system; further, by introducing external environmental factors, the mode switching conditions are optimized, thereby improving the accuracy of the switching timing, thereby improving the stability of the fuel combustion performance after the switch, and ensuring the continuous and stable operation of the engine; further, by predicting the energy compensation demand according to the load fluctuation, it is possible to adjust the parameters of the air supply system and various devices in the engine in advance to improve the smoothness of the parameter changes of each device after the switch, thereby improving the engine operation stability; further, since the configuration of the high-pressure air supply system can be predicted and dynamically adjusted according to the load fluctuation, the engine can operate efficiently in various environments, thereby improving the practicality and stability of the high-pressure air supply engine.

[0053] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The drawings herein are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application, and do not constitute an improper limitation on the present application.

[0055] Figure 1 A schematic diagram of the structure of a high-pressure air supply system in an engine fuel combustion control method based on a high-pressure air supply system provided in an embodiment of the present application;

[0056] Figure 2 A flow chart of an engine fuel combustion control method based on a high-pressure air supply system provided in an embodiment of the present application;

[0057] Figure 3 A schematic structural diagram of an engine fuel combustion control device based on a high-pressure air supply system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0058] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0059] The embodiment of the present application provides an engine fuel combustion control method based on a high-pressure air supply system, which is applied to electronic equipment, specifically to devices such as vehicle-mounted computers and mobile terminals.

[0060] Before describing the control method of the embodiment of the present application in detail, the structure of the high-pressure gas supply system is first introduced.

[0061] In actual application, the high-pressure gas supply system can be understood as a system that supplies high-pressure fuel to the engine. For example, for a liquid hydrogen engine, the high-pressure gas supply system supplies hydrogen to the engine; for a liquefied natural gas engine, the high-pressure gas supply system supplies natural gas to the engine.

[0062] Figure 1 The structure of a high pressure gas supply system is shown in FIG. Figure 1 As shown, the high-pressure gas supply system may include a fuel storage container 10, a pressurizing circuit, a high-pressure gas supply circuit, a gas recovery circuit, and an electronic control unit 50;

[0063] A liquid level sensor 11 is installed in the fuel storage container 10 and is connected to an external liquid level display system 12. A gas injection line 13 and a gas return line 14 are also installed in the fuel storage container 10. One end of the gas injection line 13 extends into the top of the fuel storage container 10, and the other end is provided with a fuel filling port 15. A liquid inlet check valve 16 is connected in series to the gas injection line 13, located between the fuel storage container 10 and the fuel filling port 15. One end of the gas return line 14 extends into the top of the fuel storage container 10, and the other end is provided with a fuel gas return port 17. A gas return stop valve 18 is connected in series to the gas return line 14, located between the fuel storage container 10 and the fuel gas return port 17. A main safety valve 19 is connected in series to the gas return line 14 of the fuel storage container 10, located between the gas return stop valve 18 and the fuel storage container 10. A secondary safety valve 101 is installed in the top of the fuel storage container 10. A system maintenance drain pipeline 102 is provided at the bottom of the fuel storage container 10 , and a liquid outlet stop valve 103 is connected in series to the system maintenance drain pipeline 102 .

[0064] The boost circuit includes an integrated valve 21 (a bypass reversing relief valve is used in this embodiment), a low-temperature high-pressure pump 22, a hydraulic pump 23, and a cooler assembly 24. The integrated valve 21 is provided with a first oil port A, a second oil port B, a third oil port P, and a fourth oil port T. The low-temperature high-pressure pump 22 is provided with a fifth oil port C, a sixth oil port D, a liquid extraction port, and a liquid discharge port. The fifth oil port C and the sixth oil port D are respectively connected to the first oil port A and the second oil port B of the integrated valve 21. The liquid extraction port is connected to the fuel storage container 10, and the liquid discharge port is connected to the high-pressure air supply line. The hydraulic pump 23 is provided with a seventh oil port E and an eighth oil port F. The cooler assembly 24 is provided with a ninth oil port G and a tenth oil port H. The seventh oil port E is connected to the third oil port P, the eighth oil port F is connected to the ninth oil port G, and the tenth oil port H is connected to the fourth oil port T. A hydraulic pressure sensor 25 is provided on the integrated valve 21.

[0065] The high-pressure gas supply circuit includes an outlet check valve 31, a pressure-maintaining valve 32, a low-temperature gas sensor 33, a normal-temperature gas temperature sensor 34, a high-pressure gas pressure sensor 35, a gas filter tank 36, and a pressure regulating valve 37 connected in series in sequence. The pressure-maintaining valve 32 and the low-temperature gas sensor 33 are used to transmit the pressure at the position of the pressure-maintaining valve 32 to the electronic control unit 50; an overpressure gas bursting disc 38 is connected in series on the high-pressure gas supply pipeline, and the overpressure gas bursting disc 38 is located in front of the gas filter tank 36.

[0066] The gas recovery circuit includes a gas return control valve 41, a first gas filter 42 and a return check valve 43 connected in series in sequence. The end of the gas return control valve 41 away from the first gas filter 42 is connected to the pressure regulating valve 37, and the end of the return check valve 43 away from the first gas filter 42 extends into the fuel storage container 10; a second gas filter 44 is also provided on the gas return control valve 41.

[0067] The low-temperature gas sensor 33 , the normal-temperature gas temperature sensor 34 , the high-pressure gas pressure sensor 35 , the gas return control valve 41 , the hydraulic pressure sensor 25 , and the liquid level display system 12 are all electrically connected to the electronic control unit 50 .

[0068] Under normal operation, the electronic control unit 50 senses that the pressure of the high-pressure gas pressure sensor 35 is below the set value and the liquid level reading from the liquid level display system 12 is normal. Furthermore, the electronic control unit 50 determines that the temperature of the ambient gas temperature sensor 34 is appropriate (-40 to +50°C). It then activates the hydraulic pump 23, initiating the circulation of hydraulic oil. The hydraulic oil flows through the integrated valve 21 and enters the low-temperature high-pressure pump 22, where it pumps liquid. After the piston of the low-temperature high-pressure pump 22 reaches a specified stroke, the electronic control unit 50 senses the pressure change and controls the integrated valve 21 to reverse, causing the piston of the low-temperature high-pressure pump 22 to reciprocate. During this process, the hydraulic oil is adjusted in temperature by the cooler assembly 24 to return to the specified value. The medium expelled from the low-temperature high-pressure pump 22 undergoes a transformation. For example, with the addition of a vaporizer, the medium is converted to a liquid-discharge check valve 31 and stored in the gas filter canister 36. It is then supplied to the engine 60 through a pressure regulating valve 37. When the pressure in the gas filter canister 36 exceeds a specified value, an overpressure gas rupture disc 38 provides protection (normally, overpressure does not occur).

[0069] When the engine 60 is shut down or encounters a pressure imbalance, the electronic control unit 50 determines that the gas in the common rail of the engine 60 is decompressed by the pressure regulating valve 37 and then returned to the gas cylinder through the gas return control valve 41, the first gas filter 42 and the return check valve 43, or is discharged to the atmosphere through the second gas filter 44.

[0070] When the fuel level in the fuel storage container 10 is lower than the set value, the fuel is added to the fuel storage container 10 through the fuel filling port 15 and the liquid inlet one-way valve 16. In order to ensure that the medium pressure in the fuel storage container 10 is lower than the pressure of the fuel filling device, the pressure can be reduced by returning air through the return air stop valve 18 and the fuel return air port 17.

[0071] During normal use, when the fuel storage container 10 is heated and the pressure of the medium inside reaches the set value of the main safety valve 19, the fuel storage container 10 will release pressure to ensure container safety. If the main safety valve 19 fails, the secondary safety valve 101 will open to release pressure and ensure the safety of the fuel storage container 10. If the fuel storage container 10 needs to be drained for maintenance, the medium inside the container can be emptied through the liquid outlet stop valve 203 to ensure safety during maintenance.

[0072] In combination with the above structure, the engine fuel combustion control method based on the high pressure air supply system of the embodiment of the present application is described below. Figure 2 As shown, the method may include S201 to S204. S201 to S204 are described in detail below in conjunction with specific embodiments.

[0073] S201: Collecting engine load state data within a first period of time.

[0074] In actual application, the load status data may be sampled according to a preset sampling period, and the first time length may be the load status data of the previous M sampling periods, where M is an integer of 1 or greater.

[0075] Here, the load state data may be an indicator that can reflect the engine power. For example, the load state data may include accelerator pedal position data, hydrogen injection amount, hydrogen injection pressure, crankshaft speed and torque, etc.

[0076] Here, the accelerator pedal position can reflect the driver's operating state. The pedal stroke can be determined according to the accelerator pedal position, thereby calculating the current actual load, that is, the actual output power.

[0077] S202: Based on the load state data, determine whether the engine meets the conditions for switching to the lean burn mode, and control the engine to switch to the lean burn mode when the switching conditions are met.

[0078] Here, the engine load range can be preset according to the engine performance parameters, thereby dividing the engine into different load ranges, and configuring corresponding control strategies for different load ranges.

[0079] Therefore, in one embodiment, the method may include configuring the standard load interval by:

[0080] The load rate interval below the value 1 is configured as a low load interval;

[0081] The load rate between value 1 and value 2, including value 1 and value 2, is configured as a medium load interval;

[0082] A load rate interval having a load rate greater than a value of 2 is configured as a high load interval.

[0083] Here, the value one and the value two may be configured in advance according to engine performance parameters, or may be configured according to historical operating parameters.

[0084] In actual application, whether to switch to the lean combustion mode can be determined based on the load range of the engine load rate.

[0085] In actual application, the value 1 and the value 2 can be understood as the dividing points for dividing the load range. The value 1 can be expressed as k1, and the value 2 can be expressed as k2. k1 and k2 can be configured in advance according to the engine combustion performance. Based on the pre-configured dividing points, the load rate value range of the low load range can be configured as (k T ,k1),k T The lower limit of the threshold value of the load interval is set, and the load rate value range of the medium load interval is configured as [k1, k2], and the load rate value range of the high load interval is configured as (k2, 1).

[0086] In actual application, when determining the switching conditions, we can judge whether the switching conditions are met based on the range of the engine load rate. For example, if the switching conditions are configured so that the load rate can switch to the lean combustion mode in the medium load range, then we can judge whether the engine load rate is in the medium load range.

[0087] It should be noted that this only focuses on whether the engine load indicator requirements in the switching conditions are met. When other requirements are configured in the switching conditions, it is necessary to determine whether to switch based on the satisfaction of other requirements and the judgment result of the engine load. That is, the condition for switching to lean combustion mode is to meet the pre-configured switching conditions of all indicators including the load rate.

[0088] In actual application, the vehicle has flow characteristics, so it may be in different application scenarios, which will cause it to be in different temperatures and air pressures; considering that the lean burn mode is highly sensitive to the external environment, in order to ensure that the present application solution can adapt to different application scenarios, improve the accuracy of the judgment results of the lean burn mode trigger conditions, and thereby improve the working stability and reliability of the engine, external environmental factors can be introduced to adjust the judgment of the load range.

[0089] Based on this, in one embodiment, the method further includes:

[0090] Based on the external environmental information, determining the degree of influence of the external temperature and pressure on the engine load threshold, and obtaining a first environmental correction coefficient; the first environmental correction coefficient includes a first temperature correction coefficient and a first pressure correction coefficient;

[0091] The determining, based on the load state data, whether the engine meets the conditions for switching to the lean burn mode, i.e., S202, may include:

[0092] determining a current load rate of the engine based on the load state data;

[0093] Correcting the preset load interval value range based on the first environmental correction coefficient to obtain a corrected load interval;

[0094] Based on the position of the engine load rate in the correction load range, it is determined whether the engine meets the conditions for switching to the lean burn mode.

[0095] In practical applications, the current actual load of the engine can be calculated based on the load status data, and then the ratio between the actual load and the rated maximum load can be used as the load rate.

[0096] In actual application, the first temperature correction coefficient can be determined based on the numerical difference between the actual temperature and the pre-configured reference temperature, and the first pressure correction coefficient can be determined based on the ratio between the actual pressure and the pre-configured reference atmospheric pressure; wherein, the reference temperature and reference pressure can be configured according to historical experience or actual application scenarios.

[0097] For example, the first temperature correction coefficient K T1 It can be expressed as:

[0098]

[0099] Among them, T e Indicates the ambient temperature, T s Indicates the preset reference temperature, which can be configured as 298K;

[0100] First pressure correction coefficient K P1 Expressed as:

[0101]

[0102] Among them, P s Indicates the reference atmospheric pressure, which can be configured as 101.3kPa, P e Indicates environmental pressure.

[0103] Here, the embodiments of the present application take into account the impact of temperature on the load threshold, specifically, taking into account that lower temperatures may reduce combustion efficiency and higher temperatures may increase the risk of knock, and also take into account the impact of pressure on the compliance threshold, specifically, taking into account that changes in atmospheric pressure will affect the engine intake volume and mixture density, thereby affecting the combustion process; by introducing a temperature correction coefficient and a pressure correction coefficient, the original load threshold can be corrected based on environmental factors, so as to adapt to different external environments and accurately and reliably control the combustion mode to ensure safe and stable operation of the vehicle. For example, in colder conditions with slightly lower atmospheric pressure, the engine needs to reach a lower load level before it is considered suitable for lean combustion mode to ensure stable operation and optimal performance.

[0104] In actual application, the product of the first temperature correction coefficient and the first pressure correction coefficient can be used as the first environmental correction coefficient; the preset load interval value range is corrected based on the first environmental correction coefficient, which can be understood as using the first environmental correction coefficient to correct the dividing point value of the preset load interval (which can also be called the dividing threshold); for the values ​​1 and 2 that divide the load interval into low load, medium load and high load intervals, the first threshold is obtained by correcting the value 1 using the first environmental correction coefficient, and the second threshold is obtained by correcting the value 2 using the first environmental correction coefficient. That is to say, the dividing point of the corrected load interval includes the first threshold and the second threshold, and these two thresholds divide the load rate into new low load, medium load and high load intervals, namely, the corrected load interval.

[0105] Based on this, in one embodiment, the modified load interval may include a first threshold and a second threshold, the first threshold being smaller than the second threshold; and determining whether the engine meets the condition for switching to the lean burn mode based on the position of the engine load rate in the modified load interval includes:

[0106] When the engine load rate is lower than a first threshold and the coolant temperature is higher than a water temperature threshold, determining that the engine meets the conditions for switching to the lean burn mode;

[0107] When the engine load rate is between a first threshold and a second threshold, it is determined that the engine meets the condition for switching to the lean burn mode.

[0108] Specifically, the first threshold can be expressed as k C1 , the second threshold can be expressed as k C2 , k C1 and k C2 Based on the revised split point, the load rate value range of the low load interval can be configured as (k T , k C1 ), configure the load rate value range of the medium load interval to [k C1 , kC2 ], the load rate value range of the high load interval is configured as (k C2 , 1); when the engine load rate is lower than the first threshold, that is, the engine is in a low-load state, it is necessary to simultaneously meet the condition that the engine is a hot engine (the coolant temperature is higher than the water temperature threshold) to determine that the engine meets the conditions for switching to the lean burn mode. Specifically, the requirements on the engine load rate in the switching conditions must be met; and when the engine load rate is between the first threshold and the second threshold (including the first threshold and the second threshold), that is, the engine is in a medium-load state, it can be directly determined that the switching conditions are met.

[0109] In actual application, when the engine load rate exceeds the second threshold, that is, it is in the high load range, lean combustion is prohibited to avoid air-fuel ratio loss of control due to insufficient power of the electric supercharger; correspondingly, when the engine load rate is between the first threshold and the second threshold, that is, it is in the medium load range, but the engine is cold (the coolant temperature is not higher than the water temperature threshold), the switching condition is not triggered, and the engine is forced to maintain equivalent combustion.

[0110] S203: Based on the load fluctuation of the engine, predict the change of the energy compensation demand of the engine within a second period after the switch, and obtain compensation information.

[0111] In actual application, when it is determined that the switching conditions are met, while switching to the lean combustion mode, the subsequent load change trend can be directly predicted based on the load change, so that the equipment parameters can be adjusted according to the load change trend to achieve timely and accurate energy compensation and ensure stable and reliable operation of the engine.

[0112] Based on this, in one embodiment, predicting the change in energy compensation demand of the engine within a second period after the switch based on the load fluctuation of the engine to obtain compensation information, i.e., S203, may include:

[0113] Determining load variation characteristics of the engine based on the load variation of the engine; the load variation characteristics include load variation rate, load fluctuation amplitude, and load fluctuation frequency;

[0114] Based on the load variation characteristics, predicting a load variation of the engine along a time axis within a second time period to obtain load fluctuation information;

[0115] Based on the load fluctuation information and pre-configured engineering constraints, an MPC algorithm is used to determine the jet engineering parameter compensation requirements of the engine within a second time period to obtain compensation information; the objective function of the MPC algorithm is to minimize power error.

[0116] In actual application, the load change of the engine is usually a continuous process of progressive change, and the load change characteristics before switching can reflect this characteristic of the load change; in the embodiment of the present application, by using the load change characteristics before switching to predict subsequent load changes, the load compensation requirements after switching can be accurately predicted by using the laws and patterns of load changes, and the control system can be prepared in advance, so that it can respond quickly at the moment of mode switching, reduce transition time, improve response efficiency, and ensure stable and continuous operation of the engine.

[0117] In actual application, the load waveform information may include the distribution information of the engine load along the time axis, and the engineering constraints may include the injection quantity range, the ignition advance angle range, etc.; after predicting the load fluctuation information of the second time period, minimizing the power error is used as the objective function, that is, minimizing the difference between the actual output power and the target power, and taking the engineering constraints as the boundary conditions, the MPC algorithm is used to determine the compensation requirements of the jet engineering parameters within the second time period.

[0118] Here, the jet engineering parameters may include injection quantity, ignition advance angle, air-fuel ratio, etc. Correspondingly, the jet engineering parameter compensation requirement may include compensation requirements for each parameter.

[0119] In practical applications, considering the impact of environmental factors on engineering parameter regulation, environmental factors can be introduced to correct the engineering parameter compensation requirements.

[0120] Therefore, in one embodiment, the method further comprises:

[0121] Based on the external environmental information, the influence of the external temperature and pressure on the engine engineering parameters is determined to obtain a second environmental correction coefficient; the second environmental correction coefficient includes a second temperature correction coefficient and a second pressure correction coefficient.

[0122] In practical applications, the influence of the external environment on engineering parameters can be introduced into the determination of compensation demand to improve the accuracy of compensation demand prediction results.

[0123] Based on this, in one embodiment, determining the jet engineering parameter compensation requirement of the engine within the second time period using the MPC algorithm to obtain compensation information may include:

[0124] Determining a predicted compensation requirement for jet engineering parameters of the engine within a second time period using an MPC algorithm;

[0125] Based on the second environmental correction coefficient, the predicted compensation demand is corrected to obtain a target compensation demand; the second environmental correction is determined based on the degree of influence of the external environment on the engineering parameters;

[0126] Compensation information is generated based on the target compensation requirement.

[0127] In actual application, the second temperature correction coefficient can be determined by the ratio of the preset reference temperature to the actual ambient temperature to reflect the influence of the external temperature on the compensation requirements, and the second pressure correction coefficient can be determined by the ratio of the actual air pressure to the reference atmospheric pressure to reflect the influence of the ambient pressure on the compensation requirements.

[0128] For example, the second temperature correction coefficient can be expressed as:

[0129]

[0130] Among them, K T2 Represents the second temperature correction coefficient, T s Indicates the reference temperature, T e Indicates the ambient temperature;

[0131] The second pressure correction coefficient can be expressed as:

[0132]

[0133] Among them, K P2 Indicates the second pressure correction coefficient, P s Indicates the reference atmospheric pressure, P e Indicates environmental pressure.

[0134] In practical applications, the second environment correction coefficient can be obtained according to the product of the second temperature correction coefficient and the second pressure correction coefficient.

[0135] S204: Determine configuration information of the high-pressure air supply system and the engine within a second time period based on the compensation information.

[0136] In actual application, the change of the engine energy compensation demand along the time axis in the second time period is determined, and the configuration information of the high-pressure air supply system (including the boost circuit, high-pressure air supply circuit, etc.) and the engine can be determined according to the changing trend and amount of the demand; how to configure the engineering parameters according to the compensation demand is a mature technology in this field and will not be repeated here.

[0137] In actual application, the configuration information includes configuration information of various engineering parameters, which is used to adjust parameters of corresponding devices according to the configuration information within the second time period.

[0138] Based on this, in one embodiment, the configuration information may include gas injection configuration information, ignition configuration information, and air-fuel ratio configuration information; and the method may further include:

[0139] Based on the configuration information, an adjustment target of the operating parameter of the high-pressure gas supply system is determined in at least one of the following ways:

[0140] determining a target injection pulse width and a target injection pressure of the gas supply system based on the gas injection configuration information;

[0141] determining a target ignition advance angle of the engine based on the ignition configuration information;

[0142] Based on the air-fuel ratio configuration information, a target air-fuel ratio of the engine is determined.

[0143] In actual applications, in order to improve the resource utilization of the engine and reduce exhaust emissions, an exhaust gas recovery loop can be added to the air supply system; in lean burn mode, due to excess air, the combustion efficiency may change, resulting in changes in the oxygen content and the proportion of other components in the exhaust gas. Therefore, the exhaust gas recovery parameters can be dynamically adjusted.

[0144] Based on this, in one embodiment, the high-pressure gas supply system further includes an EGR unit, and the EGR unit includes a gas return control valve; after switching to the lean gas mode, the method further includes:

[0145] According to a preset feedback sampling frequency, the actual injection amount of the fuel gas after compensation based on the configuration information is collected;

[0146] determining an exhaust gas recovery ratio for a next feedback sampling period based on a difference between the actual injection amount and the reference injection amount;

[0147] Based on the exhaust gas recovery ratio, the opening of the fuel gas return control valve in the EGR unit is adjusted.

[0148] In practical applications, the feedback sampling frequency can be understood as the frequency of collecting the real-time injection amount, so as to dynamically adjust the equipment parameters of the EGR unit according to the feedback of the injection amount.

[0149] In actual application, the exhaust gas recovery ratio of the next feedback sampling cycle is determined based on the difference between the actual injection amount and the benchmark injection amount. This can be understood as adjusting the exhaust gas recovery ratio of the next feedback sampling cycle based on the proportion of the difference between the actual injection amount and the benchmark injection amount in the benchmark injection amount, and then adjusting the opening of the gas return control valve.

[0150] In one embodiment, adjusting the opening of the gas return control valve in the EGR unit based on the exhaust gas recovery ratio may include:

[0151] Correcting the exhaust gas recovery ratio based on the second environmental correction coefficient to obtain a corrected exhaust gas recovery ratio;

[0152] Based on the corrected exhaust gas recovery ratio, the opening of the fuel gas return control valve in the EGR unit is adjusted.

[0153] In actual applications, the changing characteristics of the load can be predicted and compensated by the steady-state model. However, the sudden changes in the engine load (such as sudden acceleration and emergency braking) are instantaneous and nonlinear. Relying solely on steady-state predictions will lead to response lags. For example, when the driver suddenly steps on the accelerator, the engine needs to adjust the torque within milliseconds. The lean burn mode has a high air-fuel ratio and a slow combustion speed. If the sudden load is not predicted in advance, it may lead to insufficient or fluctuating torque output.

[0154] Based on this, in one embodiment, in the lean combustion mode, the method may further include:

[0155] Based on the real-time collected load data, determining whether the engine has a sudden load change;

[0156] When a sudden load change occurs in the engine, a torque deviation is determined based on the load change value;

[0157] generating a vector control instruction for performing PI control on an electrical vector of the engine based on the torque deviation; the electrical vector includes a current vector and a voltage vector;

[0158] In response to the vector control command, torque compensation is performed on the engine.

[0159] In actual application, it is possible to determine whether the engine has a sudden load change based on the speed change rate or power fluctuation. Specifically, when the engine speed change rate exceeds a preset change rate threshold, or when the power fluctuation exceeds a preset fluctuation threshold, it can be determined that the engine has a sudden load change.

[0160] Here, the current vector is used to adjust the torque output, and the voltage vector is used to stabilize the torque under sudden load conditions.

[0161] In practical applications, the current vector may include direct-axis current and quadrature-axis current. When a sudden load change occurs and the change state is load increase, the torque can be increased by increasing the quadrature-axis current. Correspondingly, when a sudden load change occurs and the change state is load reduction, the energy consumption can be reduced by reducing the quadrature-axis current and adjusting the direct-axis current.

[0162] In practical applications, the space vector pulse width modulation (SVPWM) method can be used to quickly adjust the voltage vector. Specifically, when a sudden load change occurs, the reference voltage angle is dynamically adjusted to shorten the voltage vector response time.

[0163] In one embodiment, generating a vector control instruction for performing PI control on the electrical vector of the engine based on the torque deviation may include:

[0164] determining a PI control increment based on the torque deviation;

[0165] Mapping the PI control increment to an electrical vector to obtain electrical vector compensation information;

[0166] The vector control instruction is generated based on the electrical vector compensation information.

[0167] Here, since the nonlinear characteristics of load mutation are taken into consideration, by introducing the detection of load mutation and then performing instantaneous regulation, instantaneous compensation of output power can be achieved. On the basis of predictive compensation based on load change characteristics, the transient response optimization strategy is completed, so that the reliability and accuracy of engine energy compensation can be fully guaranteed, thereby improving the stability and reliability of engine operation; further, since the flame propagation speed of lean combustion is sensitive to the concentration of the mixture, load mutation may cause the local air-fuel ratio to exceed the combustion limit, thereby causing misfire or intensified cycle fluctuations. The embodiment of the present application can dynamically adjust the injection amount, ignition timing or EGR rate by predicting the sudden load, thereby maintaining combustion stability.

[0168] In summary, the engine fuel combustion control method based on the high-pressure air supply system provided in the embodiment of the present application can detect the engine load changes in real time by collecting load status data in real time, so that the combustion mode can be switched in time when the switching conditions are met, thereby improving the response speed and stability of the system; further, by introducing external environmental factors, the mode switching conditions are optimized, thereby improving the accuracy of the switching timing, thereby improving the stability of the fuel combustion performance after the switch, and ensuring the continuous and stable operation of the engine; further, by predicting the energy compensation demand according to the load fluctuation, it is possible to adjust the parameters of the air supply system and each device in the engine in advance to improve the smoothness of the parameter changes of each device after the switch, thereby improving the engine operation stability; further, since the configuration of the high-pressure air supply system can be predicted and dynamically adjusted according to the load fluctuation, the engine can operate efficiently in various environments, thereby improving the practicality and stability of the high-pressure air supply engine.

[0169] In order to implement the engine fuel combustion control method based on the high pressure air supply system of the present application, the embodiment of the present application also provides an engine fuel combustion control device based on the high pressure air supply system, which is set on an electronic device, such as Figure 3 As shown, the device may include:

[0170] The collecting unit 301 is used to collect the load state data of the engine within a first period of time;

[0171] a control unit 302 for determining, based on the load state data, whether the engine satisfies a condition for switching to a lean burn mode, and controlling the engine to switch to the lean burn mode when the switching condition is satisfied;

[0172] The first processing unit 303 is configured to predict, based on the load fluctuation of the engine, a change in the energy compensation demand of the engine within a second period after the switching, and obtain compensation information;

[0173] The second processing unit 304 is configured to determine configuration information of the high-pressure air supply system and the engine within a second time period based on the compensation information.

[0174] In one embodiment, the control unit 302 may be configured to:

[0175] Based on the external environmental information, determining the degree of influence of the external temperature and pressure on the engine load threshold, and obtaining a first environmental correction coefficient; the first environmental correction coefficient includes a first temperature correction coefficient and a first pressure correction coefficient;

[0176] determining a current load rate of the engine based on the load state data;

[0177] Correcting the preset load interval value range based on the first environmental correction coefficient to obtain a corrected load interval;

[0178] Based on the position of the engine load rate in the correction load range, it is determined whether the engine meets the conditions for switching to the lean burn mode.

[0179] In one embodiment, the segmentation point of the modified load interval includes a first threshold and a second threshold, and the first threshold is smaller than the second threshold; the control unit 302 may be specifically configured to:

[0180] When the engine load rate is lower than a first threshold and the coolant temperature is higher than a water temperature threshold, determining that the engine meets the conditions for switching to the lean burn mode;

[0181] When the engine load rate is between a first threshold and a second threshold, it is determined that the engine meets the condition for switching to the lean burn mode.

[0182] In one embodiment, the first processing unit 303 may be configured to:

[0183] Determining load variation characteristics of the engine based on the load variation of the engine; the load variation characteristics include load variation rate, load fluctuation amplitude, and load fluctuation frequency;

[0184] Based on the load variation characteristics, predicting a load variation of the engine along a time axis within a second time period to obtain load fluctuation information;

[0185] Based on the load fluctuation information and pre-configured engineering constraints, an MPC algorithm is used to determine the jet engineering parameter compensation requirements of the engine within a second time period to obtain compensation information; the objective function of the MPC algorithm is to minimize power error.

[0186] In one embodiment, the configuration information includes gas injection configuration information, ignition configuration information, and air-fuel ratio configuration information; the second processing unit 304 may also be used to:

[0187] Based on the configuration information, an adjustment target of the operating parameter of the high-pressure gas supply system is determined in at least one of the following ways:

[0188] determining a target injection pulse width and a target injection pressure of the gas supply system based on the gas injection configuration information;

[0189] determining a target ignition advance angle of the engine based on the ignition configuration information;

[0190] Based on the air-fuel ratio configuration information, a target air-fuel ratio of the engine is determined.

[0191] In one embodiment, the high-pressure gas supply system further includes an EGR unit, and the EGR unit includes a gas return control valve. After switching to the lean gas mode, the control unit 302 can also be used to:

[0192] According to a preset feedback sampling frequency, the actual injection amount of the fuel gas after compensation based on the configuration information is collected;

[0193] determining an exhaust gas recovery ratio for a next feedback sampling period based on a difference between the actual injection amount and the reference injection amount;

[0194] Based on the exhaust gas recovery ratio, the opening of the fuel gas return control valve in the EGR unit is adjusted.

[0195] In one embodiment, adjusting the opening of the gas return control valve in the EGR unit based on the exhaust gas recovery ratio includes:

[0196] Based on the external environmental information, the influence of the external temperature and pressure on the engine engineering parameters is determined to obtain a second environmental correction coefficient; the second environmental correction coefficient includes a second temperature correction coefficient and a second pressure correction coefficient

[0197] Correcting the exhaust gas recovery ratio based on the second environmental correction coefficient to obtain a corrected exhaust gas recovery ratio;

[0198] Based on the corrected exhaust gas recovery ratio, the opening of the fuel gas return control valve in the EGR unit is adjusted.

[0199] In one embodiment, in the lean burn mode, the control unit 302 may further be configured to:

[0200] Based on the real-time collected load data, determining whether the engine has a sudden load change;

[0201] When a sudden load change occurs in the engine, a torque deviation is determined based on the load change value;

[0202] generating a vector control instruction for performing PI control on an electrical vector of the engine based on the torque deviation; the electrical vector includes a current vector and a voltage vector;

[0203] In response to the vector control command, torque compensation is performed on the engine.

[0204] In one embodiment, generating a vector control instruction for performing PI control on the electrical vector of the engine based on the torque deviation may include:

[0205] determining a PI control increment based on the torque deviation;

[0206] Mapping the PI control increment to an electrical vector to obtain electrical vector compensation information;

[0207] The vector control instruction is generated based on the electrical vector compensation information.

[0208] It should be noted that the aforementioned embodiments of the engine fuel combustion control device based on a high-pressure air supply system, when performing engine fuel combustion control based on a high-pressure air supply system, only illustrate the division of the aforementioned program modules. In actual applications, the aforementioned processing can be assigned to different program modules as needed, that is, the internal structure of the device can be divided into different program modules to complete all or part of the aforementioned processing. In addition, the engine fuel combustion control device based on a high-pressure air supply system provided in the aforementioned embodiments and the engine fuel combustion control method embodiment based on a high-pressure air supply system are based on the same concept. The specific implementation process is detailed in the method embodiment and will not be repeated here.

[0209] It should be noted that: "first", "second", etc. are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0210] In addition, the technical solutions described in the embodiments of the present application can be arbitrarily combined without conflict.

[0211] The above description is merely a preferred embodiment of the present application and is not intended to limit the scope of protection of the present application.

Claims

1. A method for controlling engine fuel combustion based on a high-pressure air supply system, characterized in that: The method comprises: Collecting engine load state data within a first period of time; determining, based on the load state data, whether the engine satisfies a condition for switching to a lean burn mode, and controlling the engine to switch to the lean burn mode when the switching condition is satisfied; Based on the load fluctuation of the engine, predicting the change of the energy compensation demand of the engine within a second period after the switching, and obtaining compensation information; Based on the compensation information, configuration information of the high-pressure air supply system and the engine within a second time period is determined.

2. The method according to claim 1, characterized in that The method further comprises: Based on the external environmental information, determining the degree of influence of the external temperature and pressure on the engine load threshold, and obtaining a first environmental correction coefficient; the first environmental correction coefficient includes a first temperature correction coefficient and a first pressure correction coefficient; The determining, based on the load state data, whether the engine meets a condition for switching to the lean burn mode includes: determining a current load rate of the engine based on the load state data; Correcting the preset load interval value range based on the first environmental correction coefficient to obtain a corrected load interval; Based on the position of the engine load rate in the correction load range, it is determined whether the engine meets the conditions for switching to the lean burn mode.

3. The method according to claim 2, characterized in that The division point of the modified load range includes a first threshold and a second threshold, the first threshold being less than the second threshold; and determining whether the engine meets the condition for switching to the lean burn mode based on the position of the engine load rate in the modified load range includes: When the engine load rate is lower than a first threshold and the coolant temperature is higher than a water temperature threshold, determining that the engine meets the conditions for switching to the lean burn mode; When the engine load rate is between a first threshold and a second threshold, it is determined that the engine meets the condition for switching to the lean burn mode.

4. The method according to claim 1, wherein The predicting, based on the load fluctuation of the engine, the change in the energy compensation demand of the engine within the second period after the switching to obtain compensation information includes: Determining load variation characteristics of the engine based on the load variation of the engine; the load variation characteristics include load variation rate, load fluctuation amplitude, and load fluctuation frequency; Based on the load variation characteristics, predicting a load variation of the engine along a time axis within a second time period to obtain load fluctuation information; Based on the load fluctuation information and pre-configured engineering constraints, an MPC algorithm is used to determine the jet engineering parameter compensation requirements of the engine within a second time period to obtain compensation information; the objective function of the MPC algorithm is to minimize power error.

5. The method according to claim 4, characterized in that The configuration information includes gas injection configuration information, ignition configuration information and air-fuel ratio configuration information; the method further includes: Based on the configuration information, an adjustment target of the operating parameter of the high-pressure gas supply system is determined in at least one of the following ways: determining a target injection pulse width and a target injection pressure of the gas supply system based on the gas injection configuration information; determining a target ignition advance angle of the engine based on the ignition configuration information; Based on the air-fuel ratio configuration information, a target air-fuel ratio of the engine is determined.

6. The method according to claim 4, characterized in that The high-pressure gas supply system further includes an EGR unit, and the EGR unit includes a gas return control valve; after switching to the lean gas mode, the method further includes: According to a preset feedback sampling frequency, the actual injection amount of the fuel gas after compensation based on the configuration information is collected; determining an exhaust gas recovery ratio for a next feedback sampling period based on a difference between the actual injection amount and the reference injection amount; Based on the exhaust gas recovery ratio, the opening of the fuel gas return control valve in the EGR unit is adjusted.

7. The method according to claim 6, characterized in that The method further comprises: Based on the external environmental information, determining the degree of influence of the external temperature and pressure on the engine engineering parameters, and obtaining a second environmental correction coefficient; the second environmental correction coefficient includes a second temperature correction coefficient and a second pressure correction coefficient; The adjusting the opening of the gas return control valve in the EGR unit based on the exhaust gas recovery ratio includes: Correcting the exhaust gas recovery ratio based on the second environmental correction coefficient to obtain a corrected exhaust gas recovery ratio; Based on the corrected exhaust gas recovery ratio, the opening of the fuel gas return control valve in the EGR unit is adjusted.

8. The method according to claim 1, characterized in that In the lean burn mode, the method further includes: Based on the real-time collected load data, determining whether the engine has a sudden load change; When a sudden load change occurs in the engine, a torque deviation is determined based on the load change value; generating a vector control instruction for performing PI control on an electrical vector of the engine based on the torque deviation; the electrical vector includes a current vector and a voltage vector; In response to the vector control command, torque compensation is performed on the engine.

9. The method according to claim 8, characterized in that The step of generating a vector control instruction for performing PI control on the electric vector of the engine based on the torque deviation includes: determining a PI control increment based on the torque deviation; Mapping the PI control increment to an electrical vector to obtain electrical vector compensation information; The vector control instruction is generated based on the electrical vector compensation information.

10. An engine fuel combustion control device based on a high-pressure air supply system, characterized in that: The device comprises: A collection unit, configured to collect load state data of the engine within a first period of time; a control unit, configured to determine, based on the load state data, whether the engine satisfies a condition for switching to a lean burn mode, and control the engine to switch to the lean burn mode when the switching condition is satisfied; A first processing unit is configured to predict, based on the load fluctuation of the engine, a change in energy compensation demand of the engine within a second period after the switching, and obtain compensation information; The second processing unit is configured to determine configuration information of the high-pressure air supply system and the engine within a second time period based on the compensation information.

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