A methanol engine full-working-condition multi-dimension collaborative combustion control system and method

Abstract

This invention discloses a multi-dimensional synergistic combustion control system and method for methanol engines under all operating conditions, belonging to the field of internal combustion engine combustion control technology. Addressing the technical problems of existing methanol engines, such as difficulty in achieving precise control of combustion state under all operating conditions, poor adaptability to operating conditions, and insufficient combustion stability, this invention achieves optimized combustion under all engine operating conditions through a multi-dimensional synergistic control strategy. Real-time engine operating condition data is collected to accurately determine the combustion mode of the target engine. Based on this, the engine intake valve operating parameters are continuously and independently controlled to dynamically optimize the in-cylinder combustion boundary conditions. Simultaneously, an active modifier is injected into the engine intake manifold, and the injection ratio is continuously adjusted in real time according to the engine operating conditions to improve the combustion activity of the air-fuel mixture. Furthermore, combining engine operating condition data with the predetermined combustion mode, the injection timing, number of injections, and injection pulse width of methanol fuel in the cylinder are precisely determined, achieving precise methanol injection at the crankshaft angle corresponding to the cylinder compression stroke.

Description

Technical Field

[0001] This invention relates to the field of internal combustion engine combustion control technology, and in particular to a methanol engine full-condition multi-dimensional coordinated combustion control system, a methanol engine full-condition multi-dimensional coordinated combustion control method, electronic equipment and storage medium. Background Technology

[0002] Methanol, as a renewable liquid fuel with high oxygen content and a single carbon structure, has significant carbon neutrality potential in the field of internal combustion engines. Based on different combustion mechanisms, methanol engines can be divided into two main technical paths: compression ignition (CI) and spark ignition (SI). Both face unique challenges arising from the physicochemical properties of methanol during operation under all conditions.

[0003] In compression ignition methanol engines:

[0004] Methanol's extremely low cetane number (CN ≈ 3–5) makes it difficult to ignite spontaneously, especially during cold starts and under low load conditions, which can easily lead to misfires or excessive cycle fluctuations. Once ignited, its high combustion rate and high latent heat of vaporization can easily cause concentrated heat release under medium to high loads, resulting in excessively high pressure rise rate, rough combustion, and threatening mechanical reliability.

[0005] In spark-ignition methanol engines:

[0006] Although methanol has a high octane rating (RON ≈ 109) and good anti-knock properties, its extremely high latent heat of vaporization (approximately 1100 kJ / kg) can significantly reduce the temperature of the in-cylinder mixture at low temperatures or low loads, leading to a decrease in flame propagation speed, unstable combustion, or even misfire. In high-load areas, the ignition angle usually needs to be significantly delayed to avoid knocking, sacrificing thermal efficiency.

[0007] Traditional solutions, such as intake electric heating, auxiliary high-activity fuel ignition, or fixed-ratio additives, generally suffer from problems such as system complexity, high energy consumption, and coarse control. More importantly, existing technologies are mostly designed for a single combustion mode and lack a unified control architecture that can simultaneously adapt to compression ignition and ignition paths and cover the entire operating range from cold start to high load.

[0008] Therefore, there is an urgent need for a collaborative control scheme that does not rely on external heating, has continuous adjustment capabilities, and is compatible with dual combustion modes, in order to enhance ignition / ignition reliability under low loads and suppress the intensity of combustion under high loads, thereby achieving efficient, stable, and reliable operation of the methanol engine across its entire operating range.

[0009] Currently, there is no publicly available technology that can effectively achieve the above goals.

[0010] The prior art document, CN121111513A, entitled "A Multi-Mode Combustion System and Control Method for a Low-Carbon Fuel Engine," focuses on achieving efficient compression ignition of low-carbon fuels (such as methanol and ammonia) through a combination of dual-fuel injection (ignition fuel + low-carbon fuel), Miller cycle regulation, an adjustable turbocharger, and an external EGR system. This approach relies on an additional ignition fuel (such as diesel) to provide the ignition source and uses complex thermal management and gas path switching to regulate the combustion process. In contrast, this invention completely eliminates the need for ignition fuel and external EGR hardware, employing only methanol as the primary fuel. It dynamically regulates the effective compression ratio and internal EGR rate through a variable valve timing mechanism (simultaneously adjusting intake valve lift and phase), and combines this with stepless proportional injection (continuously adjustable to any ratio) of intake manifold active modifiers to assist ignition under necessary operating conditions. More importantly, the control logic of this invention does not rely on multi-path valve switching or dual-fuel coordination. Instead, it is based on a pre-calibrated full-condition mapping table, achieving simple feedforward, multi-parameter coordinated control, applicable to both compression ignition and spark ignition modes. The two differ fundamentally in terms of fuel path, system complexity, control dimensions, and mode compatibility.

[0011] The prior art document, CN119616684B, entitled "A Control Method and Engine System for Fully Variable Valve," focuses on real-time monitoring of the actual valve opening / closing angle and comparison with the target angle to dynamically correct the drive signal for high-precision tracking of the valve trajectory. This approach focuses on angle servo control at the actuator level, representing low-level hardware-driven optimization, and does not address combustion strategy or fuel characteristic adaptation. In contrast, this invention addresses the full-condition combustion control requirements of methanol fuel engines. It utilizes a variable valve mechanism (simultaneously adjusting lift and phase) as an active tool for shaping the combustion boundary, deeply synergizing with the continuously variable injection ratio of the active modifier and the methanol direct injection strategy. This achieves a balance between ignition reliability and combustion smoothness under critical conditions such as cold start, low load, and high load. Summary of the Invention

[0012] In view of this, the purpose of this invention is to provide a multi-dimensional coordinated combustion control system for a methanol engine under all operating conditions, a multi-dimensional coordinated combustion control method for a methanol engine under all operating conditions, electronic equipment and storage medium. It aims to solve the technical problems of difficult ignition / ignition and unstable combustion under low load and cold start conditions, as well as the efficiency loss caused by excessive pressure rise rate or excessive delay of ignition angle to avoid knocking under medium and high load conditions, without the need for intake air heating.

[0013] This invention provides the following solution:

[0014] According to one aspect of the present invention, a multi-dimensional coordinated combustion control system for a methanol engine under all operating conditions is provided, comprising:

[0015] Variable valve timing device, fuel activator adjustment device, operating condition acquisition device, in-cylinder methanol fuel injection device, and coordinated control device;

[0016] The variable valve timing device is electrically connected to the coordinated control device and is also connected to the operating condition acquisition device for signal acquisition.

[0017] The variable valve timing device is mounted on the intake side of the engine cylinder head and is mechanically connected to the engine intake valve. It is used to continuously and independently adjust the operating parameters of the engine intake valve to dynamically control the combustion boundary conditions in the cylinder.

[0018] The fuel activator regulating device is connected to the engine intake manifold and is also electrically connected to the coordinated control device and the operating condition acquisition device; it is used to inject the activator into the engine intake manifold and continuously adjust the activator injection ratio according to the engine operating condition.

[0019] The in-cylinder methanol fuel injection device is installed in the engine cylinder, with the injection end extending into the cylinder combustion chamber and connected to the coordination control device and the operating condition acquisition device for signal transmission; it is used to inject methanol fuel into the engine cylinder.

[0020] The operating condition acquisition device is connected to the variable valve timing device, fuel activator timing device, in-cylinder methanol fuel injection device and engine sensors respectively to collect engine operating condition parameters.

[0021] The coordinated control device is connected to the variable valve timing device, fuel activator timing device, operating condition acquisition device, and in-cylinder methanol fuel injection device for coordinated regulation based on engine operating conditions and combustion mode.

[0022] Furthermore, the variable valve timing device is used to adjust the intake valve lift and phase parameters to dynamically control the in-cylinder combustion boundary conditions, which include: in-cylinder effective compression ratio, internal EGR rate, and mixture turbulence intensity.

[0023] Furthermore, the active modifiers include: combustion-supporting and auto-ignition-enhancing active components suitable for compression ignition and atomization-promoting and vaporization-enhancing blending components suitable for ignition mode.

[0024] Furthermore, the methanol fuel injection device is an in-cylinder high-pressure direct injection device, used to realize a multi-stage injection strategy.

[0025] Furthermore, the collaborative control device incorporates a full-condition calibration mapping table and employs feedforward control logic.

[0026] According to a second aspect of the present invention, a method for combustion control of a methanol engine under all operating conditions is provided, comprising the following steps:

[0027] Collect engine operating data to obtain the combustion mode of the target engine;

[0028] Continuous and independent control of engine intake valve operating parameters, dynamic adjustment of in-cylinder combustion boundary conditions;

[0029] Inject active modifier into the engine intake manifold and continuously adjust the injection ratio of active modifier according to engine operating conditions;

[0030] Based on engine operating data and combustion mode, determine the injection timing, number of injections and injection pulse width of methanol fuel in the cylinder, and control the methanol fuel injection device to perform methanol injection at the corresponding crankshaft angle position of the cylinder compression stroke.

[0031] Obtain the full-condition calibration mapping table;

[0032] Based on the full-condition calibration mapping table, the intake valve operating parameters, active improver injection ratio, and methanol injection strategy are synchronously matched and corrected.

[0033] Furthermore, dynamically adjusting the in-cylinder combustion boundary conditions specifically includes:

[0034] The control of the intake valve includes continuous and independent adjustment of the intake valve lift and phase, and dynamic control of the effective compression ratio, internal EGR rate and mixture turbulence intensity.

[0035] Furthermore, the in-cylinder methanol fuel adopts a high-pressure direct injection method, and performs one or more multi-stage injection strategies such as pre-injection, main injection, and post-injection according to the operating conditions.

[0036] According to three aspects of the present invention, an electronic device is provided, comprising: a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus;

[0037] The memory stores a computer program, which, when executed by the processor, causes the processor to perform the steps of a methanol engine combustion control method under all operating conditions.

[0038] According to four aspects of the present invention, a computer-readable storage medium is provided that stores a computer program executable by an electronic device, which, when run on the electronic device, causes the electronic device to perform the steps of a methanol engine full-condition combustion control method.

[0039] Compared with the prior art, the present invention has the following advantages:

[0040] This invention uses a high compression ratio as the basic hardware platform for a methanol compression ignition engine. Under this premise, through the deep synergy of a variable valve mechanism (simultaneously adjusting intake valve lift and phase), intake manifold injection of fuel activity modifiers (proportional stepless adjustment), and in-cylinder methanol direct injection strategy, it achieves the active shaping of the in-cylinder thermodynamic state and chemical reaction environment without the need for intake air heating, thereby covering the entire operating range from cold start and low load to high load.

[0041] This invention implements adaptive collaborative control to meet the full operating requirements of methanol engines: In compression ignition, under low load, it enhances auto-ignition by increasing intake valve lift, advancing valve closing phase, injecting cetane enhancers such as EHN, and advancing methanol main injection; under high load, it reduces valve lift, delays valve closing phase to decrease the effective compression ratio, and disables activators to suppress harsh combustion. In spark ignition, during cold starts, the variable valve mechanism sets the intake valve lift to a medium-high value and appropriately advances the intake valve opening phase to create high-intensity tumble flow in the cylinder. Simultaneously, it avoids closing the intake valve too late, ensuring that the tumble vortex is effectively broken into turbulence during the compression stroke, thereby accelerating flame propagation and improving combustion stability. It also injects highly volatile additives such as MTBE to improve mixture formation, which, combined with ignition timing, enhances combustion stability; under high load, it leverages the high anti-knock properties of methanol to reduce or disable additives, optimizing thermal efficiency. The entire system requires no intake air heating, achieving efficient and stable operation under all operating conditions. Attached Figure Description

[0042] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0043] Figure 1 This is a framework diagram of a multi-dimensional coordinated combustion control system for a methanol engine under all operating conditions, provided by one or more embodiments of the present invention.

[0044] Figure 2 This is a flowchart of a multi-dimensional coordinated combustion control method for a methanol engine under all operating conditions, provided by one or more embodiments of the present invention.

[0045] Figure 3 This is an electronic device structural block diagram of a multi-dimensional coordinated combustion control method for a methanol engine under all operating conditions, provided by one or more embodiments of the present invention. Detailed Implementation

[0046] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms, and “multiple” generally includes at least two unless the context clearly indicates otherwise.

[0048] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0049] It should be understood that although the terms first, second, third, etc., may be used in the embodiments of the present invention, these descriptions should not be limited to these terms. These terms are only used to distinguish the descriptions. For example, first may also be referred to as second without departing from the scope of the embodiments of the present invention, and similarly, second may also be referred to as first.

[0050] Depending on the context, the words "if" or "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrases "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0051] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or device that includes said element.

[0052] Figure 1 This is a framework diagram of a multi-dimensional coordinated combustion control system for a methanol engine under all operating conditions, provided by one or more embodiments of the present invention.

[0053] like Figure 1 As shown, it includes:

[0054] Variable valve timing device, fuel activator adjustment device, operating condition acquisition device, in-cylinder methanol fuel injection device, and coordinated control device;

[0055] Variable valve timing device is used to continuously and independently adjust the operating parameters of the engine intake valves to dynamically control the combustion boundary conditions in the cylinder.

[0056] A fuel activator regulating device is used to inject activator into the engine intake manifold and continuously adjust the activator injection ratio according to engine operating conditions.

[0057] In-cylinder methanol fuel injection device, used to inject methanol fuel into the engine cylinder;

[0058] Operating condition acquisition device, used to acquire engine speed, load, temperature and pressure operating condition signals;

[0059] The coordinated control device is connected to the variable valve timing device, fuel activator timing device, operating condition acquisition device, and in-cylinder methanol fuel injection device for coordinated regulation based on engine operating conditions and combustion mode.

[0060] In one embodiment, the variable valve timing device is used to adjust the intake valve lift and phase parameters to dynamically control the in-cylinder combustion boundary conditions, which include: in-cylinder effective compression ratio, internal EGR rate, and mixture turbulence intensity.

[0061] In one embodiment, the variable valve timing device dynamically controls the in-cylinder combustion boundary conditions through the coupled adjustment of intake valve lift and phase, with the specific mapping relationship as follows:

[0062] Control of the effective compression ratio in the cylinder:

[0063] Increasing the effective compression ratio (suitable for cold starts and low-load compression ignition): The co-control device controls the intake valve phase to close earlier (close to or earlier than the piston bottom dead center BDC), while simultaneously increasing the intake valve lift. This reduces intake recirculation, maximizing the actual mass of gas participating in compression, thereby increasing the in-cylinder temperature and pressure at the end of compression and improving the low-temperature auto-ignition stability of methanol.

[0064] Reducing the effective compression ratio (suitable for suppressing knock / rough combustion under medium to high loads): The co-control device controls the intake valve phase to close later (after the piston bottom dead center BDC, i.e., large Miller cycle), which can be used with medium or low lift. Some fresh charge is pushed back into the intake port at the beginning of compression, reducing the effective compression ratio, thereby suppressing the pressure rise rate and knock tendency under high loads.

[0065] Control of internal EGR rate:

[0066] Increasing the internal EGR rate: This is achieved by significantly delaying the intake valve closing time to a specific angle after bottom dead center (e.g., 30°-60° CA ABDC), utilizing the piston's upward movement to push the exhaust gas into the intake manifold; or by opening the intake valve earlier at the end of the exhaust stroke (increasing the intake and exhaust overlap angle), utilizing the intake negative pressure to draw in residual exhaust gas. This is mainly used at medium to high loads to reduce combustion temperature, suppress NOx, and mitigate harsh combustion, or to retain residual heat during deceleration to prevent uncontrolled auto-ignition.

[0067] Reduce internal EGR rate: Employ a smaller intake and exhaust overlap angle (delay intake valve opening and advance intake valve closing) to ensure thorough air exchange, suitable for rapid acceleration or high-load conditions that require maximum charging efficiency and pure, fresh charge.

[0068] Control of turbulence intensity in the mixed gas:

[0069] Enhanced Turbulence / Swirl (Suitable for cold starts and low loads in ignition mode): Employs medium-high intake valve lift and moderately advances the opening phase. The larger lift difference and specific opening timing are conducive to forming strong directional swirl during the intake stroke; at the same time, it avoids closing the intake valve too late, ensuring that the swirl vortex is not excessively dissipated during the compression stroke, but is effectively broken into small-scale turbulence, accelerating flame propagation.

[0070] Reduce turbulence (applicable to specific steady-state high-efficiency regions): Appropriately reduce the intake valve lift or adjust the phase to reduce intake kinetic energy, reduce pumping losses, and optimize part-load thermal efficiency.

[0071] In one embodiment, the active modifier includes: a combustion-supporting and auto-ignition-enhancing active component suitable for compression ignition and a misting and vaporization-enhancing blending component suitable for ignition mode.

[0072] In one specific embodiment, a fixed high compression ratio compression ignition methanol engine is used, equipped with a continuously adjustable variable valve mechanism with continuously adjustable intake valve lift / phase, an intake manifold-specific active modifier injection unit, an in-cylinder methanol high-pressure direct injection system, and a vehicle-wide coordinated control ECU. The active modifier is selected as 2-ethylhexyl nitrate (EHN) as a compression ignition-specific combustion-supporting and self-ignition active component.

[0073] With ambient temperature -35℃ and engine coolant temperature -10℃, the following coordinated control strategy is implemented:

[0074] Variable valve timing: Controls the intake valve to the designed high lift range, advances the intake valve closing phase to near the piston bottom dead center, maintains a high effective compression ratio in the cylinder, increases the temperature of the air-fuel mixture at the end of compression, and creates the basic thermodynamic conditions for methanol auto-ignition.

[0075] Active modifier injection control: The ECU retrieves the cold start calibration mapping table and controls the intake nozzle to inject 2-ethylhexyl nitrate (EHN) in a set volume ratio; EHN has a high cetane number, and after being mixed into the intake airflow, it is fully mixed with the methanol mixture, which greatly improves the overall auto-ignition activity of the mixture and makes up for the shortcomings of methanol itself, which has a cetane number of only 3~5 and is difficult to auto-ignite at low temperatures;

[0076] In-cylinder methanol injection strategy: adopts a two-stage injection mode of pilot pre-injection + main injection. The pilot injection time is appropriately advanced, relying on the EHN component to preferentially form a local ignition source to ignite the subsequent main injection methanol mixture;

[0077] Operating performance: The engine can start smoothly with a single ignition. During the cold idling stage, the combustion cycle variation coefficient COVIMEP is stably controlled within 3%, with no misfires, off-fires, or idling vibrations. No additional intake air electric heating device is required, reducing the energy consumption of vehicle accessories.

[0078] In one embodiment, the methanol fuel injection device is an in-cylinder high-pressure direct injection device used to implement a multi-stage injection strategy.

[0079] In one embodiment, the collaborative control device has a built-in full-condition calibration mapping table and uses feedforward control logic.

[0080] In one embodiment, the collaborative control device has a built-in full-condition calibration mapping table, and the feedforward control logic is specifically as follows:

[0081] The full-condition calibration mapping table is the core database for the collaborative control device to perform feedforward control. Its specific control flow is as follows:

[0082] The dimensions for constructing the calibration mapping table:

[0083] This mapping table is a two-dimensional or multi-dimensional lookup table with engine speed (RPM) and load (such as throttle pedal opening, intake air volume, or torque demand) as the two axes. The table stores at least three sets of target output parameters:

[0084] Intake valve target parameters: target intake valve lift (mm), target intake valve opening / closing phase angle (°CA).

[0085] Target parameters for active modifier: target injection ratio (%), target injection pulse width (ms).

[0086] Methanol injection target parameters: injection timing (°CA BTDC / ATDC) for pre-injection / main injection / post-injection, pulse width of each injection segment (ms), and number of injections.

[0087] Note: The above parameters distinguish between two independent MAP maps for "compression ignition mode" and "ignition mode".

[0088] Feedforward lookup table control logic:

[0089] Operating condition identification: The ECU collects speed and load signals in real time, and combines them with coolant temperature and ambient temperature to determine the current operating condition zone (such as cold start zone, low load zone, high load zone, transient transition zone) and combustion mode.

[0090] Basic value query: Using the current speed and load as indexes, perform linear interpolation calculations in the calibration MAP of the corresponding mode to obtain the basic target values ​​of each actuator.

[0091] Environmental correction: Introducing correction factors such as temperature and atmospheric pressure. For example, when the ambient temperature is detected to be below a threshold (e.g., -20°C), the cold start correction subroutine is automatically invoked to add an additional intake valve advance and an increase in the proportion of active improver to the base MAP value.

[0092] Transient prediction compensation: For transient conditions where the throttle change rate exceeds a set threshold, the ECU triggers feedforward prediction logic based on the throttle pedal change rate, switching to the preset "acceleration / deceleration transition parameter group" 1-2 seconds in advance, instead of waiting for the natural transition of the steady-state MAP, in order to eliminate response lag.

[0093] Offline persistence characteristics of calibration data:

[0094] It is emphasized that all MAP data originates from engine bench full-condition scanning calibration and vehicle road verification tests, and is then optimized and stored in the ECU read-only memory. During operation, only table lookups and feedforward outputs are performed; it does not rely on real-time feedback from cylinder pressure sensors, nor does it run online machine learning or adaptive optimization algorithms. This pure feedforward architecture significantly reduces onboard computing power requirements and ensures the determinism and reliability of the control system under extreme conditions.

[0095] It is worth noting that although only some basic functional modules are disclosed in this embodiment, it does not mean that the composition of this system is limited to the above-mentioned basic functional modules. On the contrary, what this embodiment intends to express is that, based on the above-mentioned basic functional modules, those skilled in the art can arbitrarily add one or more functional modules in combination with existing technology to form an infinite number of embodiments or technical solutions. That is to say, this system is open rather than closed. The fact that this embodiment only discloses a few basic functional modules does not mean that the scope of protection of the claims of this invention is limited to the disclosed basic functional modules. At the same time, for the convenience of description, the above device is described separately according to its functions as various units and modules. Of course, in implementing this invention, the functions of each unit and module can be implemented in one or more software and / or hardware.

[0096] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0097] Figure 2 This is a flowchart of a multi-dimensional coordinated combustion control method for a methanol engine under all operating conditions, provided by one or more embodiments of the present invention.

[0098] like Figure 2 As shown, it includes the following steps:

[0099] Step S1: Collect engine operating condition data and obtain the combustion mode of the target engine;

[0100] Step S2: Continuously and independently control the engine intake valve operating parameters to dynamically adjust the in-cylinder combustion boundary conditions;

[0101] Step S3: Inject the active modifier into the engine intake manifold and continuously adjust the injection ratio of the active modifier according to the engine operating conditions.

[0102] Step S4: Based on engine operating data and combustion mode, determine the injection timing, number of injections and injection pulse width of methanol fuel in the cylinder, and control the methanol fuel injection device in the cylinder to perform methanol injection at the corresponding crankshaft angle position during the cylinder compression stroke.

[0103] Step S5: Obtain the full-condition calibration mapping table;

[0104] Step S6: Based on the full-condition calibration mapping table, synchronously match and correct the intake valve operating parameters, active improver injection ratio, and methanol injection strategy.

[0105] Furthermore, dynamically adjusting the in-cylinder combustion boundary conditions specifically includes:

[0106] The control of the intake valve includes continuous and independent adjustment of the intake valve lift and phase, and dynamic control of the effective compression ratio, internal EGR rate and mixture turbulence intensity.

[0107] Furthermore, the in-cylinder methanol fuel adopts a high-pressure direct injection method, and performs one or more multi-stage injection strategies such as pre-injection, main injection, and post-injection according to the operating conditions.

[0108] In one embodiment, it includes: a variable valve mechanism, an intake manifold improver injection system, and an in-cylinder methanol direct injection system, which work in conjunction with the vehicle ECU to achieve coordinated control;

[0109] Variable valve mechanism: It has the ability to independently and continuously adjust the intake valve lift and intake valve phase with dual degrees of freedom. It can be switched by electro-hydraulic drive, electromagnetic drive, or mechanical cam (any structure such as MultiAir and Valvetronic). By changing the valve lift and intake valve closing time, it can flexibly adjust the effective compression ratio, in-cylinder tumble intensity, and internal EGR introduction amount to achieve fine control of combustion boundary.

[0110] Active modifier injection system: Located in the intake manifold, the modifier injection ratio is continuously and infinitely adjustable by EC control; the medium can be switched according to the engine operating mode: high cetane number modifiers such as EHN and DE are selected for compression ignition, and high volatility modifiers such as MTBE and ethanol are selected for ignition. In addition to intake manifold injection, it can also be extended to in-cylinder independent fuel rail direct injection, common rail injection with methanol, and other supply forms.

[0111] In-cylinder methanol direct injection system: Implements a staged injection strategy of single / multiple pre-injection + main injection according to the EC pre-calibrated injection scheme, and adjusts the number of injections, injection timing and injection pulse width according to different operating conditions;

[0112] The EC internally stores a full-condition offline calibration parameter table. Based on operating parameters such as throttle opening, engine speed, and ambient temperature, it looks up the corresponding valve parameters, improver injection ratio, and methanol injection parameters. It adopts feedforward control and does not rely on real-time cylinder pressure monitoring and intelligent optimization calculation. The entire hardware platform can achieve compatibility between compression ignition and spark ignition modes of methanol engines through EC logic switching.

[0113] The core architecture of this invention is not limited to a fixed cylinder compression ratio. The engine body can adopt a fixed high compression ratio or be equipped with a mechanical / hydraulic variable compression ratio structure, and the control strategy can be adaptively matched. Simultaneously, this control scheme can be extended to integrate electronic thermostats, variable turbochargers, external EGR valves, and other devices, combining overall engine thermal management with intake air optimization. Besides methanol, the control architecture, after changing the corresponding active modifier and calibration parameters, is also adaptable to difficult-to-ignite clean fuels such as ethanol, ammonia, and dimethyl ether.

[0114] In one embodiment of a cold start operation at -35°C (compression ignition methanol engine), specifically, with an ambient temperature of -35°C and no intake air heating, the EC retrieves the cold start pre-calibration parameters:

[0115] The variable valve timing mechanism controls the intake valve to switch to a high lift, advances the intake valve closing phase to near the piston bottom dead center, increases the engine's effective compression ratio, increases the cylinder temperature at the end of compression, and improves the conditions for methanol's low-temperature auto-ignition.

[0116] The intake manifold injection system injects a high cetane number improver (EHN / DE) according to the specified volume ratio to enhance the ignition activity of the intake mixture;

[0117] The in-cylinder methanol direct injection adopts a pilot injection + main injection calibration scheme;

[0118] With this collaborative control, the engine can start smoothly on the first try, and the cycle variation coefficient COVIMEP is less than 3% under cold idling conditions. Idle combustion is stable and no intake air preheating device is required.

[0119] In one embodiment, under high-load conditions (507kW, 1900rpm, compression ignition operation), the engine operates at full load and high speed, and the EC calls the high-load calibration parameters:

[0120] The variable valve timing mechanism adjusts the intake valve to a medium-high lift, delays the intake valve closing phase until after the piston's bottom dead center, introduces internal EGR, reduces the effective compression ratio, and uses the Miller cycle to suppress rough combustion.

[0121] The injection ratio of the intake manifold active improver was adjusted to 0%, and the additive supply was stopped.

[0122] The in-cylinder methanol adopts a two-pre-injection + one-main-injection control strategy, with all injection times set before or near the top dead center.

[0123] After coordinated control, the engine pressure rise rate is reduced to 0.55 MPa / °CA, which greatly alleviates the problems of high-load knocking and rough combustion, and maintains the thermal efficiency in the optimal range.

[0124] In one embodiment, during the transient transition from 30 km / h to 80 km / h, the EC (Electronic Control Unit) retrieves a preset parameter set for the acceleration condition 1.5 seconds in advance based on the rate of change of the accelerator pedal, achieving dynamic pre-control.

[0125] The variable valve can quickly switch from medium-high lift to high lift, and the intake closing phase is advanced from after bottom dead center to near bottom dead center, which improves charging efficiency and improves the reliability of methanol auto-ignition during rapid acceleration.

[0126] A metered injection of an active modifier into the air intake enhances the activity of the air-fuel mixture and optimizes transient ignition response.

[0127] The pulse width of the in-cylinder methanol main injection is increased by 25% compared to the cruise condition, and the methanol injection timing is advanced appropriately.

[0128] In actual operation, the engine torque is not delayed, there is no misfire or abnormal high pressure rise during acceleration, and the combustion phase remains stable.

[0129] In one embodiment, it includes: a city cycle variable load operating condition with frequent acceleration and deceleration from 0 to 60 km / h;

[0130] Without any intake heating, the EC retrieves preset coordination parameters in three stages: coasting, starting, and cruising.

[0131] During the deceleration coasting phase: the intake valve drops to a medium lift, and the intake valve closing phase is significantly delayed to behind the bottom dead center. The internal EGR is used to retain residual heat in the cylinder to prevent residual heat from inducing uncontrolled spontaneous combustion of methanol.

[0132] During the initial acceleration phase: the valves are switched to high lift, the intake closing phase is moved forward to near the bottom dead center, and the intake manifold is simultaneously injected with an active modifier to improve instantaneous ignition performance;

[0133] During the medium-speed cruise phase: the injection of active modifier is stopped, and the valve lift and phase are smoothly and continuously adjusted according to the load.

[0134] No external heating or real-time feedback correction is required in the full cycle operation mode, and the overall COVIMEP is controlled within 3%, ensuring stable combustion under all operating conditions.

[0135] In one specific embodiment, the following is included: the same hardware architecture switches combustion modes via internal EC logic:

[0136] Compression ignition: The intake manifold supplies high cetane number improvers such as EHN and DE, and the compression ratio is adjusted in conjunction with variable valves, so that power is achieved by compression auto-ignition;

[0137] Ignition mode: The intake manifold replaces the injection of highly volatile modifiers such as MTBE and ethanol, optimizes the low-temperature ignition performance of the mixture, and the variable valve and methanol injection parameters are simultaneously switched to the pre-calibrated lookup table parameters for the ignition condition. One hardware platform realizes two combustion paths, which facilitates the platform-based development of the engine.

[0138] Specifically, all valve adjustment data, improver injection ratio, and methanol injection timing parameters are calibrated offline after engine bench calibration and vehicle road testing, and the parameters are stored in the EC lookup unit. The vehicle operation relies on feedforward control based on the operating condition parameters, without real-time feedback from cylinder pressure sensors or online intelligent optimization algorithms, thereby reducing the computational load on the on-board controller and improving the reliability of the control system.

[0139] Figure 3 This is an electronic device structural block diagram of a multi-dimensional coordinated combustion control method for a methanol engine under all operating conditions, provided by one or more embodiments of the present invention.

[0140] like Figure 3 As shown, the present invention provides an electronic device, including: a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus;

[0141] The memory stores a computer program, which, when executed by the processor, causes the processor to perform the steps of a multi-dimensional coordinated combustion control method for a methanol engine under all operating conditions.

[0142] The present invention also provides a computer-readable storage medium storing a computer program executable by an electronic device, which, when run on the electronic device, causes the electronic device to perform the steps of a multi-dimensional coordinated combustion control method for a methanol engine under all operating conditions.

[0143] For the sake of simplicity, the method embodiments are described as a series of actions. However, those skilled in the art should understand that the embodiments of the present invention are not limited to the described order of actions, because according to the embodiments of the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions involved are not necessarily essential to the embodiments of the present invention.

[0144] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that the present invention can be implemented by means of software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in various embodiments or some parts of the embodiments of the present invention.

[0145] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-dimensional coordinated combustion control system for a methanol engine under all operating conditions, wherein the control system is compatible with both spark ignition and compression ignition combustion modes, characterized in that, include: Variable valve timing device, fuel activator adjustment device, operating condition acquisition device, in-cylinder methanol fuel injection device, and coordinated control device; The variable valve adjustment device is electrically connected to the collaborative control device and is also connected to the operating condition acquisition device for signal acquisition. The variable valve adjustment device is mounted on the intake side of the engine cylinder head and is mechanically connected to the engine intake valve. It is used to continuously and independently adjust the operating parameters of the engine intake valve to dynamically control the combustion boundary conditions in the cylinder. The fuel activator adjustment device is connected to the engine intake manifold and is also electrically connected to the collaborative control device and the operating condition acquisition device, respectively; it is used to inject the activator into the engine intake manifold and continuously adjust the activator injection ratio according to the engine operating condition. The in-cylinder methanol fuel injection device is installed in the engine cylinder, with the injection end extending into the cylinder combustion chamber and connected to the coordinated control device and the operating condition acquisition device for signal transmission; it is used to inject methanol fuel into the engine cylinder. The operating condition acquisition device is connected to the variable valve timing device, the fuel activator timing device, the in-cylinder methanol fuel injection device and the engine sensor respectively for collecting engine operating condition parameters. The coordinated control device is connected to the variable valve timing device, fuel activator timing device, operating condition acquisition device, and in-cylinder methanol fuel injection device for coordinated regulation based on engine operating conditions and combustion mode.

2. The methanol engine full-condition multi-dimensional coordinated combustion control system according to claim 1, characterized in that, include: The variable valve adjustment device is used to adjust the intake valve lift and phase parameters to dynamically control the in-cylinder combustion boundary conditions, which include: in-cylinder effective compression ratio, internal EGR rate, and mixture turbulence intensity.

3. The methanol engine full-condition multi-dimensional coordinated combustion control system according to claim 1, characterized in that, The active modifier includes: an active component suitable for compression ignition and an active component suitable for ignition mode that promotes atomization and vaporization.

4. The methanol engine full-condition multi-dimensional coordinated combustion control system according to claim 1, characterized in that, include: The methanol fuel injection device is an in-cylinder high-pressure direct injection device used to implement a multi-stage injection strategy.

5. The methanol engine full-condition multi-dimensional coordinated combustion control system according to claim 1, characterized in that, include: The collaborative control device has a built-in full-condition calibration mapping table and adopts feedforward control logic.

6. The methanol engine full-condition multi-dimensional coordinated combustion control system according to claim 1, characterized in that, The engine operating parameters include: engine speed, load, temperature, and pressure operating signals.

7. A combustion control method for a methanol engine under all operating conditions, characterized in that, include: Collect engine operating data to obtain the combustion mode of the target engine; Continuous and independent control of engine intake valve operating parameters, dynamic adjustment of in-cylinder combustion boundary conditions; Inject active modifier into the engine intake manifold and continuously adjust the injection ratio of active modifier according to engine operating conditions; Based on engine operating data and combustion mode, determine the injection timing, number of injections and injection pulse width of methanol fuel in the cylinder, and control the methanol fuel injection device to perform methanol injection at the corresponding crankshaft angle position of the cylinder compression stroke. Obtain the full-condition calibration mapping table; Based on the full-condition calibration mapping table, the intake valve operating parameters, active improver injection ratio, and methanol injection strategy are synchronously matched and corrected.

8. The methanol engine full-condition combustion control method according to claim 7, characterized in that, The dynamic adjustment of in-cylinder combustion boundary conditions specifically includes: The control of the intake valve includes continuous and independent adjustment of the intake valve lift and phase, and dynamic control of the effective compression ratio, internal EGR rate and mixture turbulence intensity.

9. An electronic device, characterized in that, include: The processor, communication interface, memory, and communication bus are connected, with the processor, communication interface, and memory communicating with each other via the communication bus. The memory stores a computer program, which, when executed by the processor, causes the processor to perform the steps of the methanol engine full-condition combustion control method according to any one of claims 7-8.

10. A computer-readable storage medium, characterized in that, It stores a computer program executable by an electronic device, which, when run on the electronic device, causes the electronic device to perform the steps of the methanol engine full-condition combustion control method as described in any one of claims 7-8.

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