A method of methanol fuel atomization control and related apparatus

Abstract

The application discloses a methanol fuel atomization control method and a related device. A methanol fuel supply system is provided with a first methanol heating flow path and a second methanol heating flow path, both of which are communicated with a methanol rail. The first methanol heating flow path exchanges heat with the methanol fuel through a heat exchange medium, and the second methanol heating flow path directly heats the methanol fuel through an electric heating device. A target heating control strategy is determined according to the comparison result of the actual state of charge of a power supply battery and the target state of charge, so that the target heating control strategy can match the current power supply capacity of the power supply battery and the heating demand of the methanol fuel, and the influence of the methanol fuel on reaching the target heating temperature due to the mismatch between the power supply capacity and the heating demand in the fixed heating mode is avoided. The adaptability of the methanol fuel heating control to different power states and different heating working conditions is improved, and the atomization effect of the methanol fuel in a cold start scene is improved.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and in particular to a methanol fuel atomization control method and related apparatus. Background Technology

[0002] With the development of clean energy technologies, methanol fuel is increasingly being used in vehicle engines. However, methanol fuel has a low saturated vapor pressure and a high latent heat of vaporization, making it difficult to evaporate at low temperatures. When methanol fuel is injected into the engine's intake system through an injector, its vaporization process absorbs heat from the surrounding environment, further lowering the temperature within the intake system and affecting the mixing efficiency between the methanol fuel and air. If the methanol fuel is not fully vaporized, some may adhere to the inner wall of the intake manifold, forming a liquid film that hinders the formation of the combustible mixture, leading to problems such as difficulty starting and unstable combustion in low-temperature environments.

[0003] In related technologies, the atomization effect of methanol fuel can be improved by increasing the fuel injection pressure.

[0004] However, in cold start scenarios, the temperatures of both methanol fuel and the intake system are low, making it difficult for methanol fuel to evaporate quickly. The atomization effect that can be achieved simply by increasing the fuel injection pressure is poor. Summary of the Invention

[0005] To address the aforementioned issues, this application provides a methanol fuel atomization control method and related apparatus to improve the atomization effect of methanol in cold start scenarios.

[0006] Based on this, the following technical solution is disclosed in this application: In a first aspect, embodiments of this application provide a methanol fuel atomization control method applied to a methanol fuel supply system. The methanol fuel supply system includes a first methanol heating flow path and a second methanol heating flow path, both connected to a methanol rail. The first methanol heating flow path is used for heat exchange with methanol fuel via a heat exchange medium, and the second methanol heating flow path is used for directly heating the methanol fuel via an electric heating device. The method includes: When the intake air temperature is lower than the intake air temperature threshold, the methanol rail pressure, the injection ambient pressure of methanol fuel, the actual temperature of methanol fuel, and the state of charge of the power supply battery are obtained. The intake air temperature threshold is used to distinguish whether the engine is in a cold start process. Determine the target heating temperature of the methanol fuel, wherein the target heating temperature is lower than the first saturation temperature corresponding to the methanol rail pressure and higher than the second saturation temperature corresponding to the injection ambient pressure; Determine the target state of charge, which is the state of charge that satisfies the second methanol heating flow path to heat the methanol fuel to the target heating temperature; Based on the comparison between the state of charge of the power supply battery and the target state of charge, a target heating control strategy is determined. According to the target heating control strategy, the methanol fuel is heated to the target heating temperature so that the methanol fuel remains liquid in the methanol rail and undergoes flash boiling after being injected into the injection environment.

[0007] Secondly, embodiments of this application provide a methanol fuel atomization control device applied to a methanol fuel supply system. The methanol fuel supply system includes a first methanol heating flow path and a second methanol heating flow path, both connected to a methanol rail. The first methanol heating flow path is used for heat exchange with methanol fuel through a heat exchange medium, and the second methanol heating flow path is used for directly heating the methanol fuel through an electric heating device. The device includes: The acquisition unit is used to acquire methanol rail pressure, methanol fuel injection ambient pressure, methanol fuel actual temperature and power supply battery state when the intake air temperature is lower than the intake air temperature threshold. The intake air temperature threshold is used to distinguish whether the engine is in a cold start process. A determining unit is used to determine the target heating temperature of the methanol fuel, wherein the target heating temperature is lower than the first saturation temperature corresponding to the methanol rail pressure and higher than the second saturation temperature corresponding to the injection ambient pressure. The determining unit is further configured to determine a target state of charge, wherein the target state of charge is a state of charge that satisfies the requirement that the second methanol heating flow path heats the methanol fuel to the target heating temperature; The determining unit is further configured to determine a target heating control strategy based on the comparison result between the state of charge of the power supply battery and the target state of charge. A heating unit is used to heat the methanol fuel to the target heating temperature according to the target heating control strategy, so that the methanol fuel remains liquid in the methanol rail and undergoes flash boiling after being injected into the injection environment.

[0008] Thirdly, embodiments of this application provide a methanol fuel supply system, which includes a methanol rail, a first methanol heating flow path, a second methanol heating flow path, and a methanol fuel atomization control module. Both the first methanol heating flow path and the second methanol heating flow path are connected to the methanol rail. The first methanol heating flow path is used to exchange heat with methanol fuel through a heat exchange medium, and the second methanol heating flow path is used to directly heat the methanol fuel through an electric heating device. The methanol fuel atomization control module is used to execute the method described in the first aspect above.

[0009] Fourthly, embodiments of this application provide a computer device, the computer device including a processor and a memory: The memory is used to store computer programs and to transfer the computer programs to the processor; The processor is configured to execute the method described in the first aspect above according to the computer program.

[0010] Fifthly, embodiments of this application provide a computer-readable storage medium for storing a computer program for performing the method described in the first aspect above.

[0011] As can be seen from the above technical solutions, this application has at least the following beneficial effects: The methanol fuel supply system is equipped with a first methanol heating flow path and a second methanol heating flow path, both connected to the methanol rail. The first methanol heating flow path exchanges heat with the methanol fuel through a heat exchange medium, while the second methanol heating flow path directly heats the methanol fuel through an electric heating device, thus providing different heating methods for the methanol fuel. Based on this, the target state of charge (SOC) is defined as the state of charge required for the second methanol heating flow path to heat the methanol fuel to the target heating temperature. A target heating control strategy is determined by comparing the actual SOC of the power supply battery with the target SOC, ensuring that the target heating control strategy matches the current power supply capacity of the power supply battery and the heating requirements of the methanol fuel. This avoids the mismatch between power supply capacity and heating requirements that can affect the methanol fuel reaching the target heating temperature when using a fixed heating method, improving the adaptability of methanol fuel heating control to different SOCs and heating conditions. Furthermore, the target heating temperature is lower than the first saturation temperature corresponding to the methanol rail pressure but higher than the second saturation temperature corresponding to the injection environment pressure. This allows the methanol fuel to remain liquid within the methanol rail and undergo flash boiling upon injection into the injection environment, thereby improving the atomization effect of the methanol fuel in cold start scenarios. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 A schematic flowchart of a methanol fuel atomization control method provided in an embodiment of this application; Figure 2 This is a schematic diagram of a methanol fuel supply system provided in an embodiment of this application; Figure 3 This is a schematic diagram comparing the effects of high-pressure spray and flash boiling spray, provided as an embodiment of this application. Figure 4 This application provides a schematic diagram of flash boiling during a methanol fuel injection process. Figure 5 This is a schematic diagram of the structure of a methanol fuel atomization control device provided in an embodiment of this application; Figure 6 This is a schematic diagram of the structure of a computer device provided in an embodiment of this application. Detailed Implementation

[0014] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While some embodiments of this application are shown in the drawings, it should be understood that this application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this application. It should be understood that the drawings and embodiments of this application are for illustrative purposes only and are not intended to limit the scope of protection of this application.

[0015] In related technologies, to improve the atomization effect of methanol fuel in low-temperature environments, the methanol fuel can be heated before injection, causing it to flash boil after being injected into a low-pressure environment. During flash boiling, the liquid methanol fuel can vaporize and break up in a short time, which helps to reduce the fuel droplet size, accelerate methanol fuel evaporation, and improve the mixing effect of methanol fuel and air.

[0016] However, related technologies typically use conventional electric heating devices to heat methanol fuel. Due to differences in the initial temperature of methanol fuel, the required temperature rise, and the state of charge of the power supply battery under different operating conditions, it is difficult to meet the heating requirements under different operating conditions simultaneously by using a fixed electric heating method, resulting in poor atomization effect of methanol fuel.

[0017] Based on this, embodiments of this application provide a methanol fuel atomization control method and related apparatus. The target state of charge (SOC) is defined as the state of charge that enables the second methanol heating flow path to heat the methanol fuel to the target heating temperature. A target heating control strategy is determined based on a comparison between the actual SOC of the power supply battery and the target SOC. This ensures that the target heating control strategy matches the current power supply capacity of the power supply battery and the heating requirements of the methanol fuel. This avoids the situation where a fixed heating method is used, where the mismatch between power supply capacity and heating requirements affects the methanol fuel reaching the target heating temperature. This improves the adaptability of methanol fuel heating control to different charge states and different heating conditions.

[0018] See Figure 1This figure is a schematic flowchart of the methanol fuel atomization control method provided in an embodiment of this application. For ease of description, the following embodiments use the control module as the executing entity of the methanol fuel atomization control method. The control module can be an engine control unit (ECU) or other controllers that are communicatively connected to the engine control unit. Figure 1 As shown, the methanol fuel atomization control method includes S101-S105.

[0019] Before introducing S101-S105, the methanol fuel supply system and methanol fuel atomization method in the embodiments of this application will be explained first.

[0020] The methanol fuel supply system includes a first methanol heating flow path and a second methanol heating flow path, both connected to the methanol rail. The first methanol heating flow path is used for heat exchange with methanol fuel through a heat exchange medium, while the second methanol heating flow path is used for direct heating of the methanol fuel via an electric heating device. Thus, two heating flow paths with different heating methods can be used to heat the methanol fuel, providing a hardware basis for determining the heating control strategy based on the power supply capacity of the battery and the actual heating requirements of the methanol fuel.

[0021] In one possible implementation, the first methanol heating flow path may sequentially include a methanol tank, a methanol pump, a first solenoid valve, a methanol fuel heat exchanger, a methanol rail, and a methanol injector. The methanol fuel heat exchanger may be connected to a water boiler, which heats the engine coolant. The heated engine coolant then flows through the methanol fuel heat exchanger as a heat exchange medium, engaging in convective heat exchange with the methanol fuel flowing through the heat exchanger, thereby transferring the heat carried by the heat exchange medium to the methanol fuel.

[0022] For example, the first methanol heating flow path can be: methanol tank → methanol pump → first solenoid valve → methanol fuel heat exchanger → methanol rail → methanol injector. When the first solenoid valve is open, methanol fuel can flow through the methanol fuel heat exchanger and be heated by the heat exchange medium; when the first solenoid valve is closed, the delivery of methanol fuel to the methanol rail through the first methanol heating flow path can be stopped.

[0023] In one possible implementation, electric heating elements can also be installed on the surface of the methanol rail. Since the temperature achievable by the heat exchange medium may be lower than the target heating temperature of the methanol fuel under high methanol rail pressure, the electric heating elements on the methanol rail surface can be activated simultaneously when heating the methanol fuel using the first methanol heating flow path. The methanol fuel heat exchanger can provide preliminary heating to the methanol fuel flowing through the first methanol heating flow path, while the electric heating elements can provide supplementary heating or insulation to the methanol fuel after it enters the methanol rail, thereby improving the ability of the first methanol heating flow path to heat the methanol fuel to the target heating temperature.

[0024] The second methanol heating flow path can sequentially include a methanol tank, a methanol pump, a second solenoid valve, an electric heating device, a methanol rail, and a methanol injector. The electric heating device can be electrically connected to a power supply battery and use the electrical energy provided by the power supply battery to directly heat the methanol fuel flowing through the second methanol heating flow path.

[0025] For example, the second methanol heating flow path can be: methanol tank → methanol pump → second solenoid valve → electric heating device → methanol rail → methanol injector. The electric heating device can be a high-pressure positive temperature coefficient (PTC) methanol fuel heater. The high-pressure PTC methanol fuel heater can be electrically connected to the vehicle's power battery or other high-voltage power supply batteries. Because the high-pressure PTC methanol fuel heater directly converts electrical energy into heat and transfers it to the methanol fuel, compared to indirectly heating the methanol fuel through a heat exchange medium, it reduces intermediate heat exchange steps and improves the heating response speed.

[0026] When heating methanol fuel using the second methanol heating flow path, the second solenoid valve can be opened and the first solenoid valve closed. Since the high-pressure PTC methanol fuel heater can directly heat the methanol fuel, the electric heating elements on the methanol rail surface can also be shut off to avoid repeated heating.

[0027] The methanol pump is a pressurization device in the methanol fuel supply system, used to draw methanol fuel from the methanol tank and pressurize it. The methanol rail is used to temporarily store the pressurized and heated methanol fuel, stabilize the methanol fuel pressure, and distribute the methanol fuel to one or more methanol injectors. The methanol rail can also be connected to a methanol temperature and pressure sensor, which is used to detect the actual temperature of the methanol fuel in the methanol rail and the methanol rail pressure, and send the detection results to the control module.

[0028] See Figure 2 This figure is a schematic diagram of a methanol fuel supply system provided in an embodiment of this application. Figure 2 As shown, the methanol tank is connected to a methanol pump, which is used to draw methanol fuel from the methanol tank and pressurize the methanol fuel. The outlet of the methanol pump is connected to both the first and second methanol heating flow paths.

[0029] The first methanol heating flow path is equipped with a first solenoid valve and a methanol fuel heat exchanger. The methanol fuel heat exchanger is also connected to a water boiler, which heats the heat exchange medium and allows the heated medium to flow through the methanol fuel heat exchanger, thereby heating the methanol fuel through heat exchange between the medium and the fuel. The methanol fuel heated by the heat exchanger can then flow into a methanol rail assembly, which includes a methanol rail and methanol temperature and pressure sensors connected to it.

[0030] The second methanol heating flow path is equipped with a second solenoid valve and a high-pressure PTC methanol fuel heater. The high-pressure PTC methanol fuel heater is electrically connected to the power battery and is used to directly heat the methanol fuel flowing through the second methanol heating flow path using the electrical energy provided by the power battery. The methanol fuel heated by the high-pressure PTC methanol fuel heater can also flow into the methanol rail assembly.

[0031] The methanol rail assembly stores and dispenses pressurized and heated methanol fuel to the methanol injectors. The methanol rail assembly can also be connected to a methanol temperature and pressure sensor, which detects the actual temperature of the methanol fuel and the methanol rail pressure within the assembly and sends the results to the control module. The control module can control the operation of the first solenoid valve, the second solenoid valve, the water boiler, and the high-pressure PTC methanol fuel heater based on a comparison between the current state of charge (SBC) of the power supply battery and the target SBC. This allows it to select the first methanol heating path, the second methanol heating path, or a combination of both to heat the methanol fuel. The methanol fuel dispensed by the methanol rail assembly can then be injected into the engine's intake system via the methanol injectors.

[0032] The methanol fuel atomization methods described in this application can include pressure injection atomization and flash boiling injection atomization. In pressure injection atomization, the methanol fuel is broken into droplets primarily by the injection pressure, the nozzle structure, and the interaction force between the methanol fuel and the surrounding gas. In flash boiling injection atomization, the methanol fuel can be preheated to a suitable temperature. When the methanol fuel is injected from a higher-pressure environment within the methanol rail to a lower-pressure injection environment, it enters a superheated state due to the rapid drop in ambient pressure and vaporizes and breaks up within a short time.

[0033] Flash boiling injection atomization can promote the formation of vapor bubbles inside methanol fuel. The expansion and collapse of vapor bubbles can further promote the breakup of liquid methanol fuel, thereby reducing the droplet size of methanol fuel, reducing the spray penetration distance, accelerating the evaporation of methanol fuel, and reducing the possibility of methanol fuel forming a liquid film after colliding with the inner wall of the intake pipe.

[0034] See Figure 3 This figure is a schematic diagram comparing the effects of high-pressure spray and flash boiling spray according to an embodiment of this application. Figure 3As shown, under high-pressure spraying, methanol fuel is mainly broken up by the injection pressure and the interaction force between the methanol fuel and the surrounding gas. The spray pattern usually has a relatively obvious jet structure, and the methanol fuel droplets mainly move along the injection direction. Under flash boiling spraying, the heated methanol fuel enters a superheated state after being injected from a higher pressure environment to a lower pressure environment. The vapor bubbles formed inside the methanol fuel expand rapidly and burst, further breaking the methanol fuel into smaller droplets, thus making the spray more dispersed.

[0035] Compared to high-pressure spray, flash boiling spray allows for jet merging, increasing the spray coverage and fuel-air contact area while reducing the spray penetration distance. This facilitates faster methanol fuel evaporation, promotes a more uniform mixture of methanol and air, and reduces the formation of a liquid film due to methanol fuel colliding with the inner wall of the intake pipe.

[0036] See Figure 4 This figure is a schematic diagram of flash boiling during a methanol fuel injection process provided in an embodiment of this application. Figure 4 As shown, heated liquid methanol fuel is injected from inside the injector. As the methanol fuel flows inside the injector, the local pressure at different locations may gradually decrease. If the temperature of the methanol fuel is higher than the saturation temperature corresponding to the local pressure, vapor bubbles can form inside the methanol fuel, resulting in internal injection flash boiling within the injector.

[0037] After the methanol fuel leaves the injector, the ambient pressure decreases further, and the methanol fuel becomes superheated relative to the injection environment. The vapor bubbles inside the droplet continue to expand and burst, resulting in external injection flash boiling. External injection flash boiling can further break up a continuous liquid column or a large droplet into more numerous and smaller droplets.

[0038] As methanol fuel continues to break down and vaporize, an evaporation zone can form around the spray. Figure 4 The evaporation surface shown represents the boundary of the area where methanol fuel evaporates and mixes with the surrounding air. Internal and external injection flash boiling can promote the breakup and evaporation of methanol fuel within a shorter distance after leaving the injector, thereby improving the atomization and air mixing effect of the methanol fuel.

[0039] S101: When the intake air temperature is lower than the intake air temperature threshold, obtain the methanol rail pressure, the injection ambient pressure of methanol fuel, the actual temperature of methanol fuel, and the state of charge of the power supply battery.

[0040] Intake air temperature is the temperature of the air before it enters the engine cylinders. For example, intake air temperature can be the temperature of the air inside the intake manifold or the air temperature detected at the engine intake port. The control module can obtain the intake air temperature through an intake air temperature sensor located in the intake manifold.

[0041] The intake air temperature threshold is a temperature threshold used to distinguish whether the engine is in a cold start process. As one implementation, the intake air temperature threshold can be determined based on the low-temperature evaporation characteristics of methanol fuel, engine model, intake system structure, methanol fuel concentration, and actual calibration results. For example, the intake air temperature threshold can be set to 16°C, or it can be set to other temperatures based on the cold start test results of different engine models; this application does not impose any restrictions on this.

[0042] When the intake air temperature is below the intake air temperature threshold, the temperature of the methanol fuel and the intake manifold is typically low. The methanol fuel does not evaporate easily after injection, and the vaporization process of the methanol fuel absorbs heat from the surrounding area of ​​the intake manifold, further reducing the temperature inside the manifold. Under these conditions, it can be determined that the engine is in a cold start process and enters the flash-boiling injection atomization control process.

[0043] In one possible implementation, after the engine is powered on, the methanol pump can be controlled to start operating, pressurizing the methanol fuel, and the methanol rail pressure within the methanol rail can be obtained through a methanol temperature and pressure sensor. By obtaining the methanol rail pressure, the temperature conditions corresponding to maintaining the methanol fuel in a liquid state within the methanol rail can be determined.

[0044] The injection environment pressure of methanol fuel is the pressure of the environment in which the methanol fuel is located after it is injected through the methanol injector. For example, when the methanol injector is installed in the intake manifold, the injection environment pressure can be the intake manifold pressure. The control module can obtain the injection environment pressure through a pressure sensor installed in the intake manifold, or it can estimate the injection environment pressure based on engine operating parameters such as engine speed, throttle opening, intake air flow, or turbocharger operating status.

[0045] The actual temperature of methanol fuel refers to its current temperature. One implementation method is to obtain the actual temperature of methanol fuel using a temperature sensor located on the methanol rail, at the outlet of the methanol fuel heat exchanger, at the outlet of the electric heating device, or in the methanol fuel pipeline. The actual temperature of methanol fuel is used to characterize the temperature rise required to heat the methanol fuel to the target heating temperature.

[0046] The State of Charge (SOC) of a power supply battery characterizes the proportion of its current remaining charge to its usable capacity. The control module can obtain the SOC from the battery management system. For example, the power supply battery could be a drive battery used to power an electric heating device, or it could be another power supply battery in the vehicle.

[0047] Therefore, after determining that the engine is in the cold start process, parameters related to the methanol fuel phase, heating requirements and power supply capacity can be obtained, providing a data basis for subsequently determining the target heating temperature and target heating control strategy.

[0048] In another possible implementation, when the intake air temperature is greater than or equal to an intake air temperature threshold, it can be determined that the engine is not in a cold start process, or that the current intake air temperature already meets the normal atomization requirements of methanol fuel. In this case, flash boiling heating of the methanol fuel can be omitted, and the methanol fuel can be injected using pressure injection atomization. For example, the first and second methanol heating paths can be closed, and the methanol pump can pressurize the methanol fuel and deliver it directly to the methanol rail, where the methanol injector uses the injection pressure to atomize the methanol fuel. This avoids continuously heating the methanol fuel when flash boiling injection is not required, reducing unnecessary heating processes.

[0049] S102: Determine the target heating temperature for methanol fuel.

[0050] The target heating temperature is lower than the first saturation temperature corresponding to the methanol rail pressure and higher than the second saturation temperature corresponding to the injection environment pressure.

[0051] The saturation temperature is the temperature at which the liquid and gaseous phases of methanol fuel reach phase equilibrium under a specified pressure. When the temperature of the methanol fuel reaches the saturation temperature corresponding to that pressure, the methanol fuel begins to transform from a liquid to a gaseous state. Therefore, for pure methanol fuel, the saturation temperature corresponding to a certain pressure can also be called the boiling point of the methanol fuel at that pressure.

[0052] The first saturation temperature is the saturation temperature of methanol fuel at the current methanol rail pressure. The second saturation temperature is the saturation temperature of methanol fuel at the current injection ambient pressure. Since the methanol rail pressure is usually higher than the injection ambient pressure, the first saturation temperature corresponding to the methanol rail pressure is usually higher than the second saturation temperature corresponding to the injection ambient pressure.

[0053] The control module can determine the first saturation temperature corresponding to the methanol rail pressure and the second saturation temperature corresponding to the injection environment pressure based on the pre-stored correspondence between pressure and saturation temperature. This correspondence can be obtained through experimental calibration, methanol fuel property data, table lookup, or saturated vapor pressure models.

[0054] For example, the methanol fuel saturation temperature corresponding to different methanol rail pressures can be found in Table 1.

[0055] Table 1

[0056] As shown in Table 1, when the methanol rail pressure is 4 bar, the corresponding first saturation temperature is 105℃; when the methanol rail pressure is 5 bar, the corresponding first saturation temperature is 115℃; and when the methanol rail pressure is 6 bar, the corresponding first saturation temperature is 125℃. These values ​​are for illustrative purposes only; the actual saturation temperature can be determined based on the purity and composition of the methanol fuel, as well as the pressure test results.

[0057] The target heating temperature is lower than the first saturation temperature, which can keep the methanol fuel in a liquid state in the high-pressure environment of the methanol rail, reduce the possibility of premature vapor bubbles being generated in the methanol rail or upstream pipeline of the injector, thereby reducing the possibility of rail pressure fluctuations, unstable fuel delivery or injection deviation.

[0058] The target heating temperature is higher than the second saturation temperature, which allows the methanol fuel to be superheated and flash boiling to occur after being injected into the lower pressure injection environment. Therefore, without causing the methanol fuel to boil prematurely within the methanol rail, the methanol fuel can be rapidly vaporized after injection, achieving phase control where the methanol fuel "remains liquid within the methanol rail and flash boiling occurs after injection".

[0059] In one possible implementation, the target heating temperature can be lower than the difference between the first saturation temperature and the first temperature margin, and higher than the sum of the second saturation temperature and the second temperature margin. The first and second temperature margins can be calibrated based on temperature sensor errors, pressure sensor errors, changes in methanol fuel composition, and pipeline heat dissipation. By reserving a temperature margin, the possibility of premature vaporization of methanol fuel within the methanol rail or failure to effectively flash boil after injection due to measurement errors or control delays can be reduced.

[0060] S103: Determine the target state of charge.

[0061] The target state of charge (SBC) is the state of charge sufficient to heat the methanol fuel to the target heating temperature by the second methanol heating circuit. In other words, it characterizes whether the power supply battery has sufficient electrical energy to support the second methanol heating circuit in completing the current methanol fuel heating task. The target SBC can be a fixed value or dynamically determined based on the electrical energy required for this heating task.

[0062] In one possible implementation, the temperature difference between the target heating temperature and the actual temperature of the methanol fuel can be determined, and the target state of charge (SOC) can be determined based on this temperature difference. A larger temperature difference indicates that more heat is required to heat the methanol fuel from the actual temperature to the target heating temperature, and correspondingly, a higher target SOC can be determined; a smaller temperature difference indicates that less heat is required for heating, and correspondingly, a lower target SOC can be determined.

[0063] For example, when the ambient temperature is low and the actual temperature of the methanol fuel is also low, the temperature difference between the target heating temperature and the actual temperature is large. The electric heating device requires more electrical energy to complete the heating task, which can increase the target state of charge. Conversely, when the methanol fuel already has a certain temperature and the temperature difference between the target heating temperature and the actual temperature is small, the electric heating device requires less electrical energy to complete the heating task, which can decrease the target state of charge.

[0064] In addition to temperature difference, the target state of charge can also be determined based on at least one of the following: methanol fuel flow rate, actual power of electric heating device, heating efficiency, expected heating time, ambient temperature, inlet air temperature, and minimum charge required for the power supply battery.

[0065] For example, a correlation between temperature difference, methanol fuel flow rate, and target state of charge can be established in advance through experiments and stored in the control module. After obtaining the temperature difference and methanol fuel flow rate, the control module can determine the target state of charge by looking up a table. Alternatively, the temperature difference, methanol fuel flow rate, and heating power of the electric heating device can be input into a pre-established energy demand model to calculate the electrical energy required for the second methanol heating path to heat the methanol fuel to the target heating temperature, and then the target state of charge can be determined based on the required electrical energy.

[0066] By dynamically determining the target state of charge, the target state of charge can reflect the actual power demand of this heating task, avoiding inaccurate judgment results due to different heating energy requirements under different operating conditions when using a fixed state of charge threshold.

[0067] S104: Determine the target heating control strategy based on the comparison between the state of charge of the power supply battery and the target state of charge.

[0068] The target heating control strategy is used to control at least one of the first methanol heating flow path and the second methanol heating flow path to heat methanol fuel. For example, the target heating control strategy may include at least one of the following: the on / off state of the first and second solenoid valves, the operating state of the water boiler, the operating state of the electric heating device, the operating state of the methanol rail surface electric heating element, the heating duration of the first and second methanol heating flow paths, the heating sequence, and the heating power.

[0069] In one possible implementation, if the state of charge of the power supply battery is greater than or equal to the target state of charge, it means that the power supply battery currently has enough electrical energy to support the second methanol heating flow path to complete the heating task. It can be determined that the second methanol heating flow path will heat the methanol fuel to the target heating temperature.

[0070] For example, the second solenoid valve can be opened, the first solenoid valve closed, and the high-pressure PTC methanol fuel heater activated, allowing methanol fuel to flow through the high-pressure PTC methanol fuel heater before entering the methanol rail. Since the high-pressure PTC methanol fuel heater directly heats the methanol fuel, the time required for the methanol fuel to reach the target heating temperature can be shortened. When using a second methanol heating path, the electric heating elements on the surface of the methanol rail can also be turned off.

[0071] When the state of charge of the power supply battery is greater than or equal to the target state of charge, the methanol fuel is heated to the target heating temperature by the second methanol heating flow path. This allows the methanol fuel to be heated directly by the electric heating device when the current power of the power supply battery is sufficient to meet the heating requirements. This reduces the intermediate heat exchange process, increases the heating rate of the methanol fuel, and enables the methanol fuel to reach the target heating temperature more quickly, thereby improving the preheating efficiency of the methanol fuel in cold start scenarios.

[0072] In another possible implementation, if the state of charge of the power supply battery is less than the target state of charge, it means that the current power of the power supply battery is not enough for the second methanol heating flow path to independently complete the heating task. It can be determined that the first methanol heating flow path will heat the methanol fuel to the target heating temperature.

[0073] For example, the second solenoid valve can be closed and the first solenoid valve opened, allowing methanol fuel to flow through the methanol fuel heat exchanger and exchange heat with the engine coolant heated by the water boiler. Simultaneously, the electric heating elements on the methanol rail surface can be activated to supplement the heating of the methanol fuel entering the methanol rail. This ensures that even when the battery's state of charge is insufficient for the high-voltage PTC methanol fuel heater to independently complete the heating task, the methanol fuel can still be heated to the target heating temperature.

[0074] When the state of charge of the power supply battery is less than the target state of charge, the methanol fuel is heated to the target heating temperature by the first methanol heating flow path. This allows the methanol fuel to be supplied with heat through the heat exchange medium when the current power of the power supply battery is insufficient to support the second methanol heating flow path to complete the heating task. This avoids the methanol fuel failing to reach the target heating temperature due to insufficient power supply capacity of the power supply battery, thereby improving the reliability of the methanol fuel heating process under low power conditions.

[0075] In another possible implementation, if the state of charge of the power supply battery is less than the target state of charge, but the power supply battery can still support the electric heating device to work for a short time, the first methanol heating flow path and the second methanol heating flow path can be controlled to jointly complete the methanol fuel heating task.

[0076] Specifically, a first target heating time corresponding to the first methanol heating flow path and a second target heating time corresponding to the second methanol heating flow path can be determined. The greater the degree to which the state of charge of the power supply battery is lower than the target state of charge, the greater the proportion of the first target heating time in the sum of the first target heating time and the second target heating time can be.

[0077] It should be noted that the above proportional relationship is used to define the direction of change and does not require that the heating time of the first target change linearly with the difference in state of charge. For example, the heating time of the first target and the heating time of the second target can be determined according to multiple state of charge intervals, or the corresponding target heating time can be determined by looking up tables, calibration curves, or control models.

[0078] For example, when the state of charge (SOC) of the power supply battery is slightly lower than the target SOC, the second methanol heating path can be used to quickly raise the methanol fuel temperature before switching to the first methanol heating path for continued heating or heat preservation. When the SOC of the power supply battery is significantly lower than the target SOC, the operating time of the second methanol heating path can be shortened while the operating time of the first methanol heating path can be extended. When the SOC of the power supply battery is low, heating can also be completed using only the first methanol heating path.

[0079] As one implementation method, the first target heating time and the second target heating time can be determined based on at least one of the following: the temperature difference between the target heating temperature and the actual temperature, the methanol fuel flow rate, the heat exchange efficiency of the first methanol heating flow path, the temperature of the heat exchange medium, the heating power of the electric heating device, and the state of charge of the power supply battery.

[0080] For example, the control module can pre-store the correspondence between different temperature differences, different states of charge, and the first and second target heating times in the background, and determine the two target heating times by looking up the table after obtaining the current temperature difference and state of charge. The control module can also calculate the two target heating times based on the calibrated heating capacity of the two heating flow paths.

[0081] The first and second methanol heating paths can heat the methanol fuel sequentially, or they can heat the methanol fuel simultaneously for at least a portion of the time. For example, the second methanol heating path can be used to rapidly raise the temperature first, and then the first methanol heating path can be used to continue raising or maintaining the temperature; alternatively, the first methanol heating path can be started first, and the second methanol heating path can be started briefly to supplement the heating if the heating capacity is insufficient; or both heating paths can be started simultaneously during the initial heating stage, and one of the heating paths can be shut off when the actual temperature of the methanol fuel approaches the target heating temperature.

[0082] Therefore, when the state of charge of the power supply battery is insufficient to support the second methanol heating flow path to independently complete the entire heating process, the second methanol heating flow path can still be used to complete part of the heating by taking advantage of its faster response speed, while the first methanol heating flow path can be used to undertake the remaining heating process, thus achieving a balance between the heating speed and the current available power of the power supply battery.

[0083] S105: According to the target heating control strategy, the methanol fuel is heated to the target heating temperature so that the methanol fuel remains liquid in the methanol rail and undergoes flash boiling after being injected into the injection environment.

[0084] The control module can control the first solenoid valve, the second solenoid valve, the water boiler, the electric heating device, and the electric heating elements on the methanol rail surface according to the target heating control strategy, and continuously or periodically obtain the actual temperature of the methanol fuel during the heating process.

[0085] If the actual temperature of the methanol fuel has not yet reached the target heating temperature, heating can continue according to the target heating control strategy. Once the actual temperature of the methanol fuel reaches the target heating temperature, heating can be stopped, or the system can switch to heat preservation control to keep the actual temperature of the methanol fuel within the preset temperature range corresponding to the target heating temperature.

[0086] In one possible implementation, when a second methanol heating path is used, the methanol fuel temperature can be controlled by adjusting the energization status or heating power of the electric heating device. When a first methanol heating path is used, the methanol fuel temperature can be controlled by adjusting the heat exchange medium flow rate, the operating status of the water boiler, the opening degree of the first solenoid valve, or the energization status of the electric heating elements on the methanol rail surface. When both heating paths operate simultaneously, the operating status of the two heating paths can be dynamically adjusted based on the difference between the actual temperature and the target heating temperature.

[0087] Because the target heating temperature is lower than the first saturation temperature corresponding to the methanol rail pressure, the methanol fuel can remain in a liquid state after entering the methanol rail, which helps to maintain the stability of the methanol rail pressure and injection volume. After the methanol fuel is injected into the low-pressure injection environment through the methanol injector, because the target heating temperature is higher than the second saturation temperature corresponding to the injection environment pressure, the methanol fuel can quickly enter a superheated state and undergo flash boiling.

[0088] Flash boiling can promote the rapid breakup and evaporation of methanol fuel, improve the mixing effect of methanol fuel and air, reduce the situation where unevaporated methanol fuel adheres to the inner wall of the intake manifold to form a liquid film, and make it easier for the engine to form a combustible mixture that meets the ignition requirements during cold start, thereby improving the low-temperature start performance and combustion stability of methanol engines.

[0089] As can be seen from the above technical solution, the methanol fuel supply system is equipped with a first methanol heating flow path and a second methanol heating flow path, both connected to the methanol rail. The first methanol heating flow path exchanges heat with the methanol fuel through a heat exchange medium, while the second methanol heating flow path directly heats the methanol fuel through an electric heating device, thus providing different heating methods for the methanol fuel. Based on this, the target state of charge (SOC) is defined as the state of charge that allows the second methanol heating flow path to heat the methanol fuel to the target heating temperature. A target heating control strategy is determined by comparing the actual SOC of the power supply battery with the target SOC, ensuring that the target heating control strategy matches the current power supply capacity of the power supply battery and the heating requirements of the methanol fuel. This avoids the mismatch between power supply capacity and heating requirements that would affect the methanol fuel reaching the target heating temperature when using a fixed heating method, improving the adaptability of methanol fuel heating control to different SOCs and heating conditions. Furthermore, the target heating temperature is lower than the first saturation temperature corresponding to the methanol rail pressure but higher than the second saturation temperature corresponding to the injection environment pressure, allowing the methanol fuel to remain liquid within the methanol rail and undergo flash boiling after injection into the injection environment, thereby improving the atomization effect of the methanol fuel in cold start scenarios.

[0090] See Figure 5 , Figure 5 A methanol fuel atomization control device provided in this application embodiment is applied to a methanol fuel supply system. The methanol fuel supply system includes a first methanol heating flow path and a second methanol heating flow path, both connected to a methanol rail. The first methanol heating flow path is used for heat exchange with methanol fuel through a heat exchange medium, and the second methanol heating flow path is used for directly heating the methanol fuel through an electric heating device. The device 500 includes: The acquisition unit 501 is used to acquire the methanol rail pressure, the injection ambient pressure of methanol fuel, the actual temperature of methanol fuel, and the state of charge of the power supply battery when the intake air temperature is lower than the intake air temperature threshold. The intake air temperature threshold is used to distinguish whether the engine is in a cold start process. The determining unit 502 is used to determine the target heating temperature of the methanol fuel, wherein the target heating temperature is lower than the first saturation temperature corresponding to the methanol rail pressure and higher than the second saturation temperature corresponding to the injection environment pressure. The determining unit 502 is further configured to determine a target state of charge, wherein the target state of charge is a state of charge that satisfies the requirement that the second methanol heating flow path heats the methanol fuel to the target heating temperature; The determining unit 502 is further configured to determine a target heating control strategy based on the comparison result between the state of charge of the power supply battery and the target state of charge. Heating unit 503 is used to heat the methanol fuel to the target heating temperature according to the target heating control strategy, so that the methanol fuel remains liquid in the methanol rail and undergoes flash boiling after being injected into the injection environment.

[0091] Optionally, the determining unit 502 is specifically used for: If the state of charge of the power supply battery is greater than or equal to the target state of charge, then it is determined that the methanol fuel will be heated to the target heating temperature by the second methanol heating flow path.

[0092] Optionally, the determining unit 502 is specifically used for: If the state of charge of the power supply battery is less than the target state of charge, then the methanol fuel is determined to be heated to the target heating temperature by the first methanol heating flow path.

[0093] Optionally, the determining unit 502 is specifically used for: If the state of charge of the power supply battery is less than the target state of charge, then a first target heating time corresponding to the first methanol heating flow path and a second target heating time corresponding to the second methanol heating flow path are determined. The greater the degree to which the state of charge of the power supply battery is lower than the target state of charge, the greater the proportion of the first target heating time in the sum of the first target heating time and the second target heating time. Based on the first target heating time and the second target heating time, the first methanol heating flow path and the second methanol heating flow path are controlled to heat the methanol fuel until the actual temperature of the methanol fuel reaches the target heating temperature.

[0094] Optionally, the determining unit 502 is specifically used for: Determine the temperature difference between the target heating temperature and the actual temperature; The target state of charge is determined based on the temperature difference, wherein the greater the temperature difference, the higher the target state of charge.

[0095] Optionally, the device 500 further includes a pressurization unit for: When the intake air temperature is greater than or equal to the intake air temperature threshold, the methanol fuel is controlled to be injected using a pressure injection atomization method.

[0096] Optionally, the electric heating device is a high-pressure positive temperature coefficient (PTC) methanol fuel heater, which is electrically connected to the power supply battery and is used to heat the methanol fuel flowing through the second methanol heating path.

[0097] See Figure 6This application also provides a computer device, which includes a memory 601 and a processor 602. The memory is used to store computer programs and to transfer the computer programs to the processor; The processor is used to execute the method of the above method embodiment according to the computer program.

[0098] This application also provides a computer-readable storage medium for storing a computer program for executing the methods described in the above-described method embodiments.

[0099] This application embodiment also provides a methanol fuel supply system, which includes a methanol rail, a first methanol heating flow path, a second methanol heating flow path, and a methanol fuel atomization control module. Both the first methanol heating flow path and the second methanol heating flow path are connected to the methanol rail. The first methanol heating flow path is used to exchange heat with methanol fuel through a heat exchange medium, and the second methanol heating flow path is used to directly heat the methanol fuel through an electric heating device. The methanol fuel atomization control module is used to execute the method described in the above method embodiment.

[0100] This application also provides a computer program product including a computer program, which, when run on a computer device, causes the computer device to perform the method described in the above method embodiments.

[0101] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems or apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and relevant parts can be referred to the method section.

[0102] The term "comprising" and its variations as used herein are open-ended inclusions, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the description below.

[0103] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0104] It should also be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0105] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0106] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for controlling methanol fuel atomization, characterized in that, An application is made in a methanol fuel supply system, the methanol fuel supply system including a methanol pump, and a first methanol heating flow path and a second methanol heating flow path, both connected to a methanol rail. The first methanol heating flow path is used for heat exchange with methanol fuel through a heat exchange medium, and the second methanol heating flow path is used for directly heating the methanol fuel through an electric heating device. The method includes: When the intake air temperature is lower than the intake air temperature threshold, the flash boiling injection atomization control process is entered, and the methanol rail pressure, the injection ambient pressure of methanol fuel, the actual temperature of methanol fuel and the state of charge of the power supply battery are acquired. The intake air temperature threshold is used to distinguish whether the engine is in a cold start process. Determine the target heating temperature of the methanol fuel, wherein the target heating temperature is lower than the first saturation temperature corresponding to the methanol rail pressure and higher than the second saturation temperature corresponding to the injection ambient pressure; Determine the target state of charge, which is the state of charge that satisfies the second methanol heating flow path to heat the methanol fuel to the target heating temperature; Based on the comparison between the state of charge of the power supply battery and the target state of charge, a target heating control strategy is determined. According to the target heating control strategy, the methanol fuel is heated to the target heating temperature so that the methanol fuel remains liquid in the methanol rail and undergoes flash boiling after being injected into the injection environment; When the intake air temperature is greater than or equal to the intake air temperature threshold, the methanol fuel is not subjected to flash boiling heating, the first methanol heating flow path and the second methanol heating flow path are closed, the methanol pump pressurizes the methanol fuel and directly delivers it to the methanol rail, and controls the methanol fuel to be injected using a pressure injection atomization method.

2. The method according to claim 1, characterized in that, The step of determining the target heating control strategy based on the comparison between the state of charge of the power supply battery and the target state of charge includes: If the state of charge of the power supply battery is greater than or equal to the target state of charge, then it is determined that the methanol fuel will be heated to the target heating temperature by the second methanol heating flow path.

3. The method according to claim 1, characterized in that, The step of determining the target heating control strategy based on the comparison between the state of charge of the power supply battery and the target state of charge includes: If the state of charge of the power supply battery is less than the target state of charge, then the methanol fuel is determined to be heated to the target heating temperature by the first methanol heating flow path.

4. The method according to claim 1, characterized in that, The step of determining the target heating control strategy based on the comparison between the state of charge of the power supply battery and the target state of charge includes: If the state of charge of the power supply battery is less than the target state of charge, then a first target heating time corresponding to the first methanol heating flow path and a second target heating time corresponding to the second methanol heating flow path are determined. The greater the degree to which the state of charge of the power supply battery is lower than the target state of charge, the greater the proportion of the first target heating time in the sum of the first target heating time and the second target heating time. Based on the first target heating time and the second target heating time, the first methanol heating flow path and the second methanol heating flow path are controlled to heat the methanol fuel until the actual temperature of the methanol fuel reaches the target heating temperature.

5. The method according to claim 1, characterized in that, Determining the target state of charge includes: Determine the temperature difference between the target heating temperature and the actual temperature; The target state of charge is determined based on the temperature difference, wherein the greater the temperature difference, the higher the target state of charge.

6. The method according to claim 1, characterized in that, The electric heating device is a high-pressure positive temperature coefficient (PTC) methanol fuel heater, which is electrically connected to the power supply battery and is used to heat the methanol fuel flowing through the second methanol heating path.

7. A methanol fuel atomization control device, characterized in that, An application is made in a methanol fuel supply system, the methanol fuel supply system including a methanol pump, and a first methanol heating flow path and a second methanol heating flow path, both connected to a methanol rail. The first methanol heating flow path is used for heat exchange with methanol fuel through a heat exchange medium, and the second methanol heating flow path is used for directly heating the methanol fuel through an electric heating device. The device includes: The acquisition unit is used to enter the flash boiling injection atomization control process when the intake air temperature is lower than the intake air temperature threshold, and to acquire the methanol rail pressure, the injection ambient pressure of methanol fuel, the actual temperature of methanol fuel, and the state of charge of the power supply battery. The intake air temperature threshold is used to distinguish whether the engine is in the cold start process. A determining unit is used to determine the target heating temperature of the methanol fuel, wherein the target heating temperature is lower than the first saturation temperature corresponding to the methanol rail pressure and higher than the second saturation temperature corresponding to the injection ambient pressure. The determining unit is further configured to determine a target state of charge, wherein the target state of charge is a state of charge that satisfies the requirement that the second methanol heating flow path heats the methanol fuel to the target heating temperature; The determining unit is further configured to determine a target heating control strategy based on the comparison result between the state of charge of the power supply battery and the target state of charge. A heating unit is used to heat the methanol fuel to the target heating temperature according to the target heating control strategy, so that the methanol fuel remains liquid in the methanol rail and undergoes flash boiling after being injected into the injection environment; The pressurization unit is used to prevent the methanol fuel from being flash-boiled and heated when the intake air temperature is greater than or equal to the intake air temperature threshold, and to control the methanol fuel to be injected using a pressure injection atomization method.

8. A methanol fuel supply system, characterized in that, The methanol fuel supply system includes a methanol rail, a first methanol heating flow path, a second methanol heating flow path, and a methanol fuel atomization control module. Both the first methanol heating flow path and the second methanol heating flow path are connected to the methanol rail. The first methanol heating flow path is used to exchange heat with methanol fuel through a heat exchange medium, and the second methanol heating flow path is used to directly heat the methanol fuel through an electric heating device. The methanol fuel atomization control module is used to perform the method described in any one of claims 1-6.

9. A computer device, characterized in that, The computer device includes a processor and memory: The memory is used to store computer programs and to transfer the computer programs to the processor; The processor is configured to perform the method according to any one of claims 1-6 according to the computer program.

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