Fuel injection control method and apparatus, and electronic control unit, engine, vehicle and storage medium

Abstract

A fuel injection control method and apparatus, and an electronic control unit, an engine, a vehicle and a computer-readable storage medium. The fuel injection control method is applied to an engine, and the method comprises: when an instruction to start an engine is detected, determining a target injection amount of fuel, wherein the vapor pressure of the fuel at a target temperature of the engine is lower than or equal to a preset vapor pressure, the target temperature being lower than or equal to a preset temperature of the engine; and when it is detected that the engine has been in a compression stroke, on the basis of the target injection amount, injecting fuel into a cylinder (302) of the engine, so as to successfully start the engine.

Description

Fuel injection control method, device, electronic control unit, engine, vehicle and storage medium

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202311110913.4, filed on August 30, 2023, the entire text of which is incorporated herein by reference. Technical Field

[0003] The present application relates to, but is not limited to, the field of engine fuel processing, and in particular to a fuel injection control method, device, electronic control unit, engine, vehicle, and computer-readable storage medium. Background Art

[0004] As carbon neutrality progresses, the demand for alternative energy sources other than gasoline is growing. Take methanol as an example. As a green energy source, methanol is already comparable to gasoline in terms of reliability and durability.

[0005] Summary of the Invention

[0006] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0007] The present application provides a fuel injection control method, device, electronic control unit, engine, vehicle and computer-readable storage medium.

[0008] According to a first aspect of the present application, a fuel injection control method is provided, which is applied to an engine, and the method includes: when an instruction to start the engine is detected, determining a target injection amount of fuel, wherein the vapor pressure of the fuel at the target temperature of the engine is less than or equal to a preset vapor pressure, and the target temperature is less than or equal to the preset temperature of the engine; when it is detected that the engine is in a compression stroke, based on the target injection amount, injecting the fuel into the cylinder of the engine to successfully start the engine.

[0009] According to a second aspect of the present application, a fuel injection control device is provided, which is applied to an engine, and the device includes: a determination unit, which is configured to determine a target injection amount of fuel when an instruction to start the engine is detected, wherein the vapor pressure of the fuel at the target temperature of the engine is less than or equal to a preset vapor pressure, and the target temperature is less than or equal to the preset temperature of the engine; and an injection unit, which is configured to inject the fuel into the cylinder of the engine based on the target injection amount when detecting that the engine is in a compression stroke, so that the engine can be started successfully.

[0010] According to a third aspect of the present application, an electronic control unit is provided, comprising: a processor; and a memory for storing processor-executable instructions; wherein the processor is configured to implement the fuel injection control method as described in the first aspect.

[0011] According to a fourth aspect of the present application, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the fuel injection control method as described in the first aspect is implemented.

[0012] According to a fifth aspect of the present application, an engine is provided, comprising the electronic control unit as described in the third aspect.

[0013] According to a sixth aspect of the present application, a vehicle is provided, comprising the engine as described in the fifth aspect.

[0014] The fuel injection control method provided in this application addresses situations where the fuel vapor pressure is low and difficult to evaporate when the engine temperature is equal to or below a preset temperature. Considering that during the engine's compression stroke, the engine's piston rapidly compresses the gas within the cylinder, generating a large amount of heat, the method injects fuel into the cylinder during the compression stroke. The fuel absorbs the significant heat generated by the gas within the cylinder and rapidly evaporates, mixing with air to form a highly effective combustible mixture. This allows the difficult-to-evaporate fuel to more easily mix with air to form a highly effective combustible mixture, even in low-temperature environments. This reduces the difficulty of spark plug ignition, thereby easing the difficulty of starting the engine at low temperatures.

[0015] It should be understood that the above general description and the following detailed description are only exemplary and explanatory and cannot limit the present application. Other aspects can be understood after reading and understanding the drawings and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technology descriptions. The drawings described below only illustrate some of the embodiments described in this application. For those skilled in the art, other drawings can also be obtained based on these drawings.

[0017] FIG1 is a schematic diagram of a fuel processing scenario in the related art.

[0018] FIG2 is a flow chart of a fuel injection control method according to an embodiment of the present application.

[0019] FIG3 is a schematic diagram of a specific application scenario of fuel processing according to an embodiment of the present application.

[0020] FIG4 is a schematic structural diagram of a fuel injection control device according to an embodiment of the present application.

[0021] FIG5 is a schematic structural diagram of an electronic control unit according to an embodiment of the present application. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the present application, the embodiments of the present application will be described in detail below in conjunction with the drawings in the embodiments of the present application. The described embodiments are only some embodiments of the present application, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application should fall within the scope of protection of this application.

[0023] As carbon neutrality progresses, the demand for alternative energy sources other than gasoline is growing. Take methanol as an example. As a green energy source, methanol is already comparable to gasoline in terms of reliability and durability.

[0024] Taking methanol as an example, compared to gasoline and other gasoline alternatives, methanol has a higher flash point (12°C), a greater latent heat of vaporization, and a lower vapor pressure at low temperatures. When the engine temperature is low, methanol evaporates more slowly and struggles to mix with air to form a combustible mixture, making it difficult to start a methanol engine at low temperatures.

[0025] Please refer to Figure 1 , and the following is an exemplary introduction to a fuel processing scenario in the related art.

[0026] In the related art, during the intake stroke of the engine, the intake valve 104 opens and the exhaust valve 105 closes, allowing the piston 103 to move away from the spark plug 101, creating a negative pressure in the cylinder 102, causing fuel to be sucked into the cylinder 102 from the intake pipe. During the compression stroke, both the intake valve 104 and the exhaust valve 105 are closed, and the piston 103 moves toward the spark plug 101 and compresses the mixed gas in the cylinder 102, converting mechanical energy into internal energy. At the same time, the spark plug 101 ignites the compressed mixed gas, which, when ignited, can do work on the piston, converting internal energy into mechanical energy. The above steps are repeated in a cycle, allowing the engine to continue running and achieve successful engine starting. However, taking methanol as an example of engine fuel, compared to gasoline and other alternative energy sources for gasoline, methanol has a higher flash point (12°C), a larger latent heat of vaporization, and a lower vapor pressure in a low-temperature environment. When the engine temperature is low, methanol is difficult to evaporate and difficult to mix with air in the cylinder 102 to form an effective combustible mixture. During the compression stroke of the engine, the spark plug 101 is difficult to ignite the methanol fuel in the cylinder 102, making it difficult to start the methanol engine at low temperatures.

[0027] In response to the above problems, related technologies provide the following solutions.

[0028] For methanol engines, the gasoline tank, fuel supply, and injection system are retained. When starting the engine at low temperatures, gasoline is used. Once the engine temperature is sufficiently high, methanol is switched to the engine fuel. However, this solution requires the addition of a separate gasoline fuel supply and injection system, increasing costs and deployment complexity. It also relies heavily on gasoline and requires users to refill gasoline regularly, making it inconvenient.

[0029] Methanol engines use heaters to heat the engine's intake air and coolant, enabling them to start at low temperatures. However, the high temperatures required, coupled with the high power and bulk of these heaters, pose significant challenges to engine layout and cost. Furthermore, the long preheating time required makes it difficult to quickly start methanol engines at low temperatures.

[0030] It is understandable that the above introduction to the fuel processing scenario is only an example display. In actual application, other fuel processing scenarios are not excluded and are not specifically limited to this.

[0031] In view of this, one embodiment of the present application provides a fuel injection control method, which is applied to an engine and can reduce the difficulty of spark plug ignition, thereby reducing the difficulty of starting the engine at low temperatures. As shown in Figure 2, the method includes the following steps S201 and S202.

[0032] In step S201 , when an instruction to start the engine is detected, a target injection amount of fuel is determined, wherein the vapor pressure of the fuel at a target temperature of the engine is less than or equal to a preset vapor pressure, and the target temperature is less than or equal to a preset temperature of the engine.

[0033] The above fuel can be implemented in various ways. For example, the above fuel can be methanol, ethanol, or other fuels that have a low vapor pressure at low temperatures, that is, are difficult to evaporate. The specific implementation of the above fuel is not limited.

[0034] The above-mentioned engine can be configured on a variety of movable devices, such as automobiles, ships and other movable devices. There is no specific limitation on the movable devices that the above-mentioned engine can be configured on.

[0035] The engine start instruction can be implemented in a variety of ways. For example, in one implementation, the engine is a vehicle engine, which can be started by a starter. The engine start instruction can be a start command sent to the starter when a user wishes to start the vehicle. Upon receiving the command, the starter can start the engine accordingly, i.e., start the engine's crankshaft. It is worth noting that the above description of the engine start instruction implementation is merely illustrative. In actual applications, other implementations are possible, and this specific implementation is not intended to be limiting.

[0036] The target injection amount can be determined in a variety of ways. For example, in one implementation, determining the target fuel injection amount can include determining the target fuel injection amount based on the intake air volume during the engine's intake stroke. It is worth noting that the above description of the method for determining the target injection amount is merely illustrative; in actual applications, other methods of determination are not excluded. For example, the target injection amount can also be determined based on the engine's air-fuel ratio and current engine temperature. The method for determining the target injection amount is not specifically limited.

[0037] As an example, the target injection amount may be predetermined and stored, or may be calculated in real time, which is not particularly limited.

[0038] For example, the preset engine temperature can serve as an indicator for an engine cold start. Starting the engine when the current engine temperature is less than or equal to the preset temperature constitutes an engine cold start. For example, the preset temperature can be 0°C, -10°C, -20°C, -30°C, -40°C, or the like.

[0039] It is understood that, given the characteristics of the aforementioned fuels, when the fuels are at a target engine temperature less than or equal to the aforementioned preset temperature, their vapor pressure is less than or equal to the preset vapor pressure. This preset vapor pressure can indicate the difficulty of evaporating the fuel at low temperatures. The lower the vapor pressure, the higher the latent heat of vaporization, making evaporation more difficult. For example, compared to other fuels, methanol has a higher flash point (12°C) and a higher latent heat of vaporization, resulting in a lower vapor pressure at low temperatures. Therefore, evaporation at low temperatures is more difficult.

[0040] In step S202 , when it is detected that the engine is in a compression stroke, the fuel is injected into a cylinder of the engine based on the target injection quantity, so that the engine is successfully started.

[0041] There are various methods for injecting fuel. For example, in one implementation, injecting the fuel into the engine cylinder based on the target injection amount may include: injecting the fuel into the engine cylinder multiple times based on the target injection amount. During a compression stroke, while the total amount of fuel injected, i.e., the target injection amount, remains constant, the fuel is injected into the cylinder multiple times, with the sum of the multiple injections equaling the target injection amount. This prevents fuel wall wetting, which can occur due to excessive single injection amount or prolonged single injection time, resulting in a long fuel beam penetration distance. Fuel wall wetting refers to the fact that the cylinder walls require protection and are typically protected by engine oil. Injecting fuel onto the walls may wash away the protective oil, causing wear and tear, and make it more difficult for the fuel adhering to the walls to evaporate. Furthermore, it allows the injected fuel to more fully absorb the heat generated by the compression work, completing evaporation.

[0042] Considering that during the compression stroke of the engine, the engine is often ignited by the spark plug, and during the ignition time of the spark plug, the combustible mixture near the spark plug needs to reach a certain concentration before the spark plug can ignite successfully.

[0043] To address the above issue, as an example, the ignition timing of the engine during the compression stroke can be determined. Based on the target injection quantity and the ignition timing, the fuel can be injected into the cylinder of the engine multiple times. The timing of the final injection of fuel into the cylinder of the engine is determined based on the ignition timing. When multiple fuel injections are performed during a compression stroke of the engine, determining the final injection timing based on the ignition timing ensures that the concentration of the combustible mixture near the spark plug is as high as possible during ignition, thereby increasing the engine's spark plug ignition success rate.

[0044] The ignition timing can be determined in a variety of ways. For example, in one implementation, the ignition timing can be determined based on the compression top dead center (CTDC) of the engine during the compression stroke. This CTDC can be the top dead center of the engine's piston. It should be noted that the above-described method for determining the ignition timing is merely illustrative; in actual applications, other methods are not excluded and are not specifically limited thereto.

[0045] For example, the final injection time of the fuel into the cylinder of the engine can be determined within a 20-degree crank angle range before or after the crankshaft position corresponding to the ignition time, where the crankshaft is the crankshaft of the engine. Completing the final injection of the fuel within a 20-degree crank angle range before or after the crankshaft position corresponding to the ignition time can significantly increase the probability of successful spark ignition.

[0046] As an example, the time of the last injection of fuel into the cylinder of the above-mentioned engine can be synchronized with the above-mentioned ignition time, or it can be within a range of 20 degrees before and after the above-mentioned ignition time, and the 20 degrees can represent the difference between the angle of the engine crankshaft and the corresponding angle of the crankshaft position at the above-mentioned ignition time.

[0047] The compression stroke range described above can be implemented in various ways. For example, in one implementation, the compression stroke range can be from 180 degrees before top dead center (TDC) to the TDC of the engine piston, where 180 degrees can represent the angle of the engine crankshaft. It should be noted that the specific implementation of the compression stroke range described above is merely illustrative; other implementations are possible in actual applications and are not intended to be limiting.

[0048] As an example, the fuel can be injected into the cylinder of the engine in multiple times based on the target injection amount and the current temperature of the engine, wherein the number of times the fuel is injected corresponds to the current temperature of the engine. The number of times the target injection amount of fuel is injected into the cylinder is determined based on the current temperature of the engine. The number of injections within the same compression stroke can be determined based on the current temperature of the engine. When the current temperature is low, the fuel demand is high, so the number of injections is increased. When the current temperature is high, the fuel demand is low, so the number of injections is reduced. The number of fuel injections can be flexibly adapted to the current temperature of the engine, which can increase the ignition success rate while reducing fuel waste at low temperatures.

[0049] As an example, the number of times the fuel is injected may also be determined based on the engine crankshaft speed. It is understood that the engine crankshaft speed can affect the duration of the compression stroke.

[0050] As an example, the fuel may be directly injected into the cylinder of the engine by controlling a direct injection injector, or the fuel may be directly injected into the cylinder of the engine by other means, without limitation.

[0051] It is worth noting that the above-mentioned introduction of the fuel injection method is only an example display. In actual application, other injection methods are not excluded and no specific limitation is made to this.

[0052] The current engine temperature can be determined in a variety of ways. For example, in one implementation, the current engine temperature can be determined by measuring the engine's intake air temperature and the engine coolant temperature. It should be noted that the above-described method for determining the current engine temperature is merely illustrative. In actual applications, other determination methods are not excluded and are not specifically limited to this method.

[0053] When the fuel is injected into the cylinder of the engine multiple times, the injection amount of the fuel injected each time can be the same or different. As an example, the injection amount of the fuel injected for the first time can be the largest, for example, the injection amount of the fuel injected for the first time can be more than 50% of the target injection amount. Increasing the injection amount of the fuel injected for the first time during multiple injections can make the total evaporation amount of the fuel corresponding to the target injection amount as large as possible. It is worth noting that the above description of the specific implementation method of the injection amount of the fuel injected each time is only an example. In actual application, other specific implementation methods are not excluded and are not specifically limited to this.

[0054] The stroke of the engine (e.g., the compression stroke) can be determined in a variety of ways. As an example, the stroke of the engine can be determined by the crankshaft angle and camshaft angle of the engine. It is understandable that the crankshaft angle can characterize the movement position of the engine piston, and the camshaft angle can assist in characterizing the number of revolutions of the crankshaft. The combination of the two can determine the stroke of the engine. It is worth noting that the above introduction to the method of determining the stroke of the engine is only an example. In actual application, other determination methods are not excluded and are not specifically limited to this.

[0055] As an example, the crankshaft angle can be determined by a crankshaft position sensor of the engine, and the camshaft angle can be determined by a camshaft position sensor of the engine. The crankshaft angle and the camshaft angle can also be determined by other methods, which are not specifically limited.

[0056] As an example, the fuel injection control method described in any of the above embodiments may be triggered to be executed when the current temperature of the engine is less than or equal to a preset temperature of the engine.

[0057] Please refer to Figure 3, and the following is an exemplary introduction to a specific application scenario of fuel processing according to an embodiment of the present application.

[0058] The current stroke of the engine can be determined by the angle of the engine's crankshaft 304. During the engine's compression stroke, both the intake valve 305 and the exhaust valve 306 are closed, and the piston 303 moves toward the spark plug 301, compressing the gas in the cylinder 302, converting mechanical energy into internal energy. The piston 303 rapidly compresses the gas in the engine's cylinder 302, performing work on the gas therein and generating a large amount of heat. During the compression stroke, fuel (such as methanol) can be injected into the cylinder 302. The fuel (such as methanol) absorbs the large amount of heat generated by the gas in the cylinder 302 and quickly evaporates, mixing with the air to form an effective combustible mixture. Simultaneously, the spark plug 301 ignites the compressed mixture, which, when ignited, performs work on the piston, converting internal energy into mechanical energy. By repeating these steps repeatedly, the engine can continue to operate and successfully start. In this way, even in a low temperature environment, fuels that are difficult to evaporate, such as methanol, can be easily mixed with air to form an effective combustible mixture, making it easier for the engine's spark plug 301 to ignite, thereby reducing the difficulty of starting the engine at low temperatures.

[0059] It is worth noting that the above introduction to the specific application scenarios of fuel processing of this application is only an exemplary display. In actual application, other specific application scenarios are not excluded and no specific limitation is made to this.

[0060] The fuel injection control method provided in the embodiments of the present application addresses situations where the fuel vapor pressure is low and difficult to evaporate when the engine temperature is equal to or less than a preset temperature. Considering that during the engine's compression stroke, the engine's piston rapidly compresses the gas within the engine's cylinder, performing work on the gas within the cylinder and generating a large amount of heat, fuel can be injected into the cylinder during the compression stroke. The fuel absorbs the large amount of heat generated by the gas within the cylinder and rapidly evaporates, mixing with air to form an effective combustible mixture. This allows the difficult-to-evaporate fuel to more easily mix with air to form an effective combustible mixture, even in low-temperature environments. This reduces the difficulty of spark plug ignition, thereby reducing the difficulty of starting the engine at low temperatures.

[0061] Corresponding to the above method embodiment, the present application also provides a fuel injection control device for an engine. Referring to FIG4 , the device may include a determination unit 401 and an injection unit 402 .

[0062] The determination unit 401 is configured to determine a target injection amount of fuel when an instruction to start the engine is detected, wherein the vapor pressure of the fuel at a target temperature of the engine is less than or equal to a preset vapor pressure, and the target temperature is less than or equal to a preset temperature of the engine.

[0063] The injection unit 402 is configured to inject the fuel into the cylinder of the engine based on the target injection quantity when detecting that the engine is in a compression stroke, so as to successfully start the engine.

[0064] As an example, the injection unit 402 is specifically configured to inject the fuel into the cylinder of the engine in multiple times based on the target injection amount.

[0065] As an example, the injection unit 402 is also used to determine the ignition time of the engine during the compression stroke; based on the ignition time, determine the time of the last injection of the fuel into the cylinder of the engine in the process of injecting the fuel into the cylinder of the engine multiple times.

[0066] As an example, the time of the last injection of the fuel into the cylinder of the engine is determined based on a crank angle range of 20 degrees before and after the engine crankshaft position corresponding to the ignition time.

[0067] As an example, the injection unit 402 is specifically configured to inject the fuel into the cylinder of the engine multiple times based on the target injection amount and the current temperature of the engine, wherein the number of times the fuel is injected corresponds to the current temperature of the engine.

[0068] As an example, the injection amount of the fuel injected first is the largest.

[0069] As an example, the fuel includes methanol or ethanol.

[0070] Corresponding to the above method embodiments, as a specific application, the above embodiments can be applied to an electronic control unit (ECU). Therefore, the present application also provides an ECU, as shown in FIG5 , which may include: a processor 501; a memory 502 for storing processor-executable instructions; wherein the processor 501 is configured to implement the fuel injection control method described in any of the above embodiments.

[0071] It is worth noting that each embodiment of the above fuel injection control method is applicable to the process in which the processor 501 injects fuel into the cylinder of the engine during the compression stroke of the engine.

[0072] The present application also provides an engine, comprising the electronic control unit as described above.

[0073] The present application also provides a vehicle comprising the engine as described above.

[0074] The present application also provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the fuel injection control method described in any one of the above embodiments is implemented. The computer-readable storage medium may include a non-transitory computer-readable storage medium.

[0075] The above description is only a specific embodiment of the present application. It should be noted that, for those skilled in the art, without departing from the principles of the present application, several improvements and modifications can be made, and these improvements and modifications should also be considered to fall within the scope of protection of the present application.

Claims

1. A fuel injection control method, applied to an engine, the method comprising: When a command to start the engine is detected, a target injection amount of fuel is determined, wherein the vapor pressure of the fuel at a target temperature of the engine is less than or equal to a preset vapor pressure, and the target temperature is less than or equal to a preset temperature of the engine; When it is detected that the engine is in a compression stroke, the fuel is injected into a cylinder of the engine based on the target injection amount so that the engine is successfully started.

2. The method according to claim 1, wherein: The injecting the fuel into the cylinder of the engine based on the target injection amount includes: The fuel is injected into the cylinder of the engine in a plurality of times based on the target injection amount.

3. The method according to claim 2, further comprising: determining an ignition timing of the engine during the compression stroke; Based on the ignition timing, the time of the last injection of the fuel into the cylinder of the engine in the process of injecting the fuel into the cylinder of the engine in multiple times is determined.

4. The method according to claim 3, wherein: The time of the last injection of the fuel into the cylinder of the engine is determined based on a crank angle range of 20 degrees before and after the engine crankshaft position corresponding to the ignition time.

5. The method according to any one of claims 2 to 4, wherein: The step of injecting the fuel into the cylinder of the engine in multiple steps comprises: Based on the target injection amount and the current temperature of the engine, the fuel is injected into the cylinder of the engine in multiple times, wherein the number of times the fuel is injected corresponds to the current temperature of the engine.

6. The method according to any one of claims 2 to 5, wherein: The injection amount of the fuel injected into the cylinder of the engine for the first time is the largest.

7. The method according to any one of claims 2 to 6, wherein: The injection amount of the fuel injected into the cylinder of the engine for the first time is 50% or more of the target injection amount.

8. The method according to any one of claims 1 to 7, wherein: The method is triggered and executed when the current temperature of the engine is less than or equal to the preset temperature.

9. The method according to any one of claims 1 to 8, wherein: The fuel includes methanol or ethanol.

10. A fuel injection control device, applied to an engine, comprising: The determination unit is configured to determine a target injection amount of the fuel when a command to start the engine is detected, wherein the vapor pressure of the fuel at the target temperature of the engine is less than or equal to a preset vapor pressure, and the target The temperature is less than or equal to a preset temperature of the engine; The injection unit is configured to inject the fuel into the cylinder of the engine based on the target injection amount when detecting that the engine is in a compression stroke, so as to successfully start the engine.

11. An electronic control unit, comprising: processor; a memory for storing processor-executable instructions; Wherein, the processor is configured to implement the fuel injection control method according to any one of claims 1 to 9.

12. A computer-readable storage medium having a computer program stored thereon, wherein: When the computer program is executed by a processor, the fuel injection control method according to any one of claims 1 to 9 is implemented.

13. An engine comprising the electronic control unit according to claim 11.

14. A vehicle comprising the engine according to claim 13.

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