A mode control method for a diesel and ammonia dual-fuel engine

Abstract

This invention provides a mode control method, device, electronic equipment, and storage medium for a diesel and ammonia dual-fuel engine. The method includes: operating the diesel and ammonia dual-fuel engine in pure diesel mode during the start-up process from a stopped state, and under operating conditions where the load percentage is less than 20%; switching from pure diesel mode to the dual-fuel mode based on a first preset switching method when the diesel and ammonia dual-fuel engine is operating under operating conditions where the load percentage is between 20% and 100%; automatically switching to pure diesel mode based on a second preset switching method when the diesel and ammonia dual-fuel engine is operating in the dual-fuel mode; and manually switching to pure diesel mode based on a third preset switching method when the diesel and ammonia dual-fuel engine is operating in the dual-fuel mode. This disclosure helps improve the stability of engine operation, especially during changes in operating conditions and combustion mode adjustments, and improves engine reliability.

Description

Technical Field

[0001] This invention belongs to the field of internal combustion engine control technology, and specifically relates to a mode control method, device, electronic equipment, and computer-readable storage medium for a diesel and ammonia dual-fuel engine. Background Technology

[0002] Compared to typical hydrocarbon fuels, ammonia is a zero-carbon fuel, producing only water and nitrogen upon complete combustion. However, complete combustion of ammonia in internal combustion engines is difficult to achieve, mainly due to its inherent characteristics such as low laminar combustion velocity and calorific value, high ignition energy requirements, and a narrow flammability limit. Therefore, a dual-fuel combustion mode using diesel to ignite ammonia is an important combustion technology route for internal combustion engines.

[0003] In existing technologies, a diesel-ignited high-pressure direct injection liquid ammonia internal combustion engine injection control method and combustion system operate in pure diesel mode during engine start-up or low-load conditions. When the internal combustion engine meets the liquid ammonia injection conditions and the piston moves to near the top dead center of compression, the diesel-ammonia nozzle is opened to inject a predetermined amount of diesel and liquid ammonia into the main combustion chamber for compression combustion. After diesel compression ignition, the liquid ammonia is heated and flash-boiled in the main combustion chamber and ignited by the diesel combustion flame to form stable diffusion combustion. A multi-point low-pressure injection ammonia and diesel dual-fuel engine and combustion organization method, by organizing the mixture to form a reasonable active concentration gradient stratification, ensures reliable ignition and stable combustion of the dual-fuel engine under various load conditions, thereby improving the power performance and emission performance of the dual-fuel engine. However, the above-mentioned combustion control methods are conceptual and based on the engine's steady-state operating conditions, and do not involve or only briefly mention the switching of combustion modes and the corresponding coordinated control methods of various systems during the change of operating conditions.

[0004] Therefore, one or more methods are needed to solve the above problems.

[0005] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] The present invention provides a mode control method, apparatus, electronic device, and computer-readable storage medium for a diesel and ammonia dual-fuel engine, thereby overcoming, at least to some extent, one or more problems caused by the limitations and defects of related technologies.

[0007] According to one aspect of this disclosure, a mode control method for a diesel and ammonia dual-fuel engine is provided, comprising:

[0008] The dual-fuel diesel and ammonia engine operates in pure diesel mode from the shutdown state to the start-up process, and under the condition that the load percentage is less than 20%, without supplying ammonia fuel; the diesel injection pressure and timing are set according to the pure diesel mode Map target value, and the diesel injection pulse width is controlled by the speed PID closed loop.

[0009] When the diesel and ammonia fuel dual-fuel engine is running under the condition of a load percentage greater than or equal to 20% and less than or equal to 100%, it switches from the pure diesel mode to the dual-fuel mode based on a first preset switching method.

[0010] When the dual-fuel engine (diesel and ammonia fuel) is running in dual-fuel mode, it automatically switches to pure diesel mode based on a second preset switching method.

[0011] When the dual-fuel engine (diesel and ammonia fuel) is running in dual-fuel mode, it can be manually switched to pure diesel mode based on a third preset switching method.

[0012] In one exemplary embodiment of this disclosure, the first preset switching method further includes:

[0013] Step S100: Receive a switching command from the user to switch from the pure diesel mode to the dual-fuel mode;

[0014] Step S101: Determine whether the engine load percentage is between 20% and 100%. If not, proceed to step S102; if yes, proceed to step S103.

[0015] Step S102: The combustion mode output is "pure diesel mode", and a switching failure prompt / alarm signal is output;

[0016] Step S103: The combustion mode outputs "diesel to ammonia mode", indicating that the engine is in the transition stage of switching from diesel to dual fuel, and then proceeds to step S104.

[0017] Step S104: In the "diesel-to-ammonia mode", the engine speed is controlled in a closed loop by adjusting the diesel injection pulse width. The injection pulse width is increased by a negative feedforward increment, which is determined by the ammonia fuel injection pulse width and its slope and the calorific value ratio of the two fuels. The diesel injection pressure and timing are adjusted to the target values ​​in the diesel injection Map of the dual-fuel mode according to the preset slope. The ammonia fuel injection pressure and pulse width are increased to the target values ​​in the corresponding Map according to the preset slope, and the injection timing is based on the Map target value. After the target ammonia fuel injection pulse width reaches the target value in the corresponding Map, proceed to step S105.

[0018] Step S105: Continuously determine the actual ammonia fuel injection quantity for 10 seconds, and determine whether the error of the ratio between the actual ammonia fuel injection quantity and the target ammonia fuel injection quantity is always less than or equal to ±2%. If the determination is successful, proceed to step S106; otherwise, proceed to step S107.

[0019] Step S106: Mode switching successful, combustion mode output "dual fuel mode";

[0020] Step S107: The combustion mode outputs "ammonia to diesel mode" and proceeds to step S108;

[0021] Step S108: Maintain closed-loop control of engine speed and adjust diesel injection pulse width. Increase the positive feedforward increment of injection pulse width. This increment is determined by the ratio of the calorific value of the two fuels, namely ammonia fuel injection pulse width and its slope. Adjust diesel injection pressure and timing to the corresponding target values ​​in Map under pure diesel mode according to the preset slope. Decrease ammonia fuel injection pressure and pulse width according to the preset slope, and adjust injection timing according to Map.

[0022] Step S109: Determine whether the error between the diesel injection quantity and the target value in pure diesel mode within 2 seconds is less than or equal to 2%. If the determination is unsuccessful, return to step S107; if the determination is successful, proceed to step S110.

[0023] Step S110: Control the ammonia fuel injection valve to close, then return to step S102.

[0024] In one exemplary embodiment of this disclosure, the method further includes:

[0025] The preset slope is positively correlated with the engine's operating load percentage and is calibrated and generated based on the engine's actual operating state.

[0026] In one exemplary embodiment of this disclosure, the method further includes:

[0027] The actual ammonia fuel injection quantity is calculated based on the fuel injector parameters and the actual injection pressure and injection pulse width, or obtained by querying the preset ammonia fuel injector characteristic Map based on the actual parameters.

[0028] The target ammonia fuel injection quantity is calculated using the injection pressure, injection pulse width, and fuel injector parameters in the speed-load percentage map, or obtained by querying a preset ammonia fuel injector characteristic map based on relevant theoretical parameters.

[0029] In one exemplary embodiment of this disclosure, the second preset switching method further includes:

[0030] Step S201: In "dual fuel mode", determine whether the engine load percentage falls within a reasonable range. If the engine load percentage falls within the preset range, proceed to step S202. If the engine load percentage does not fall within the preset range, proceed to step S203.

[0031] Step S202: Keep the dual-fuel mode unchanged and output "dual-fuel mode" in the combustion mode;

[0032] Step S203: Determine whether the load percentage is less than the lower limit of the preset range. If yes, proceed to step S205; otherwise, proceed to step S204.

[0033] Step S204: Determine whether the load exceeds the preset upper limit within 1 second. If not, return to step S202; if yes, proceed to step 205.

[0034] Step S205: Switch the combustion mode and output "ammonia to diesel mode", and proceed to step S206;

[0035] Step S206: Adjust the diesel injection pulse width to perform closed-loop control of the engine speed. The injection pulse width is increased by a positive feedforward increment, which is determined by the ratio of the calorific value of the two fuels, namely the ammonia fuel injection pulse width and its slope. The diesel injection pressure and timing are adjusted to the corresponding target values ​​in Map under pure diesel mode according to the preset slope. Under the "ammonia to diesel mode", the ammonia fuel injection pressure and pulse width are reduced according to the preset slope.

[0036] Step S207: Determine whether the error between the diesel injection quantity and the target value in pure diesel mode within 2 seconds is less than or equal to 2%. If not, return to step S206; if yes, proceed to step S208.

[0037] Step S208: Control the ammonia fuel injection valve to close, and output the combustion mode as "pure diesel mode".

[0038] In one exemplary embodiment of this disclosure, the method further includes:

[0039] The preset range is 15% ≤ load percentage ≤ 103%.

[0040] In one exemplary embodiment of this disclosure, the third preset switching method further includes:

[0041] Step S301: In "dual fuel mode", a switching command is manually issued, and the combustion mode output is "ammonia to diesel mode";

[0042] Step S302: Adjust the diesel injection pulse width to perform closed-loop control of the engine speed. Increase the positive feedforward increment of the injection pulse width. The increment is determined by the ratio of the calorific value of the two fuels, namely the ammonia fuel injection pulse width and its slope. Adjust the diesel injection pressure and timing to the corresponding target values ​​in Map under pure diesel mode according to the preset slope. Decrease the ammonia fuel injection pressure and pulse width according to the preset slope.

[0043] Step S303: Check whether the error between the diesel injection quantity and the target value in pure diesel mode within 2 seconds is less than or equal to 2%. If not, return to step S302; if yes, proceed to step S304.

[0044] Step S304: Control the ammonia fuel injection valve to close, and output the combustion mode as "pure diesel mode".

[0045] In one aspect of this disclosure, a mode control device for a diesel and ammonia dual-fuel engine is provided, comprising:

[0046] The pure diesel operation module is used to operate the dual-fuel diesel and ammonia engine in pure diesel mode during the start-up process from the shutdown state, and under the condition that the load percentage is less than 20%, without supplying ammonia fuel; the diesel injection pressure and timing are set according to the target value of the pure diesel mode Map, and the diesel injection pulse width is controlled by the speed PID closed loop;

[0047] The first switching module is used to switch the diesel and ammonia fuel dual-fuel engine from the pure diesel mode to the dual-fuel mode based on a first preset switching method when the load percentage is greater than or equal to 20% and less than or equal to 100%.

[0048] The second switching module is used to automatically switch to the pure diesel mode based on a second preset switching method when the diesel and ammonia fuel dual-fuel engine is running in the dual-fuel mode.

[0049] The third switching module is used to manually switch to the pure diesel mode based on a third preset switching method when the diesel and ammonia fuel dual-fuel engine is running in the dual-fuel mode.

[0050] In one aspect of this disclosure, an electronic device is provided, comprising:

[0051] Processor; and

[0052] A memory storing computer-readable instructions that, when executed by the processor, implement the method according to any one of the preceding claims.

[0053] In one aspect of this disclosure, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the method according to any one of the preceding claims.

[0054] An exemplary embodiment of this disclosure provides a mode control method for a diesel and ammonia dual-fuel engine. The method includes: operating the diesel and ammonia dual-fuel engine in a pure diesel mode during the start-up process from a stopped state, and under operating conditions where the load percentage is less than 20%; switching from the pure diesel mode to the dual-fuel mode based on a first preset switching method when the diesel and ammonia dual-fuel engine is operating in the dual-fuel mode; automatically switching to the pure diesel mode based on a second preset switching method when the diesel and ammonia dual-fuel engine is operating in the dual-fuel mode; and manually switching to the pure diesel mode based on a third preset switching method when the diesel and ammonia dual-fuel engine is operating in the dual-fuel mode. This disclosure helps improve the stability of engine operation, especially during changes in operating conditions and combustion mode adjustments, thereby improving engine reliability.

[0055] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0056] The above and other features and advantages of this disclosure will become more apparent from the detailed description of exemplary embodiments thereof with reference to the accompanying drawings.

[0057] Figure 1 A flowchart of a mode control method for a diesel and ammonia dual-fuel engine according to an exemplary embodiment of the present disclosure is shown;

[0058] Figure 2A-2C A logic flowchart of each switching method of a mode control method for a diesel and ammonia dual-fuel engine according to an exemplary embodiment of the present disclosure is shown.

[0059] Figure 3 A structural block diagram of a mode control device for a diesel and ammonia dual-fuel engine according to an exemplary embodiment of the present disclosure is shown;

[0060] Figure 4 A block diagram of an electronic device according to an exemplary embodiment of the present disclosure is shown schematically;

[0061] Figure 5 The illustration shows a schematic diagram of a computer-readable storage medium according to an exemplary embodiment of the present disclosure. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0063] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted.

[0064] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure can be practiced without one or more of the specific details described, or other methods, components, materials, apparatuses, steps, etc., can be employed. In other instances, well-known structures, methods, apparatuses, implementations, materials, or operations are not shown or described in detail to avoid obscuring various aspects of this disclosure.

[0065] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, or in one or more software-hardened modules, or in different network and / or processor devices and / or microcontroller devices.

[0066] In this example embodiment, a mode control method for a diesel and ammonia dual-fuel engine is first provided; refer to Figure 1 As shown, the mode control method for a diesel and ammonia dual-fuel engine may include the following steps:

[0067] In step S1100, the dual-fuel diesel and ammonia engine operates in pure diesel mode from the shutdown state to the start-up process, and under the condition that the load percentage is less than 20%, without supplying ammonia fuel; the diesel injection pressure and timing are set according to the pure diesel mode Map target value, and the diesel injection pulse width is controlled by the speed PID closed loop.

[0068] In step S1200, when the diesel and ammonia fuel dual-fuel engine is running under the condition of a load percentage greater than or equal to 20% and less than or equal to 100%, it switches from the pure diesel mode to the dual-fuel mode based on the first preset switching method.

[0069] Step S1300: When the diesel and ammonia fuel dual-fuel engine is running in the dual-fuel mode, it automatically switches to the pure diesel mode based on the second preset switching method.

[0070] In step S1400, when the diesel and ammonia fuel dual-fuel engine is running in the dual-fuel mode, it is manually switched to the pure diesel mode based on the third preset switching method.

[0071] An exemplary embodiment of this disclosure provides a mode control method for a diesel and ammonia dual-fuel engine. The method includes: operating the diesel and ammonia dual-fuel engine in a pure diesel mode during the start-up process from a stopped state, and under operating conditions where the load percentage is less than 20%; switching from the pure diesel mode to the dual-fuel mode based on a first preset switching method when the diesel and ammonia dual-fuel engine is operating in the dual-fuel mode; automatically switching to the pure diesel mode based on a second preset switching method when the diesel and ammonia dual-fuel engine is operating in the dual-fuel mode; and manually switching to the pure diesel mode based on a third preset switching method when the diesel and ammonia dual-fuel engine is operating in the dual-fuel mode. This disclosure helps improve the stability of engine operation, especially during changes in operating conditions and combustion mode adjustments, thereby improving engine reliability.

[0072] The following will further explain a mode control method for a diesel and ammonia dual-fuel engine in this example embodiment.

[0073] Example 1:

[0074] In step S1100, the dual-fuel engine (diesel and ammonia fuel) can operate in pure diesel mode during the start-up process from a stopped state, and under conditions where the load percentage is less than 20%, without supplying ammonia fuel; the diesel injection pressure and timing are set according to the pure diesel mode Map target value, and the diesel injection pulse width is controlled by the speed PID closed loop.

[0075] In step S1200, when the diesel and ammonia dual-fuel engine is running under the condition that the load percentage is greater than or equal to 20% and less than or equal to 100%, it can switch from the pure diesel mode to the dual-fuel mode based on the first preset switching method.

[0076] In this example embodiment, the first preset switching method further includes:

[0077] Step S100: Receive a switching command from the user to switch from the pure diesel mode to the dual-fuel mode;

[0078] Step S101: Determine whether the engine load percentage is between 20% and 100%. If not, proceed to step S102; if yes, proceed to step S103.

[0079] Step S102: The combustion mode output is "pure diesel mode", and a switching failure prompt / alarm signal is output;

[0080] Step S103: The combustion mode outputs "diesel to ammonia mode", indicating that the engine is in the transition stage of switching from diesel to dual fuel, and then proceeds to step S104.

[0081] Step S104: In the "diesel-to-ammonia mode", the engine speed is controlled in a closed loop by adjusting the diesel injection pulse width. The injection pulse width is increased by a negative feedforward increment, which is determined by the ammonia fuel injection pulse width and its slope and the calorific value ratio of the two fuels. The diesel injection pressure and timing are adjusted to the target values ​​in the diesel injection Map of the dual-fuel mode according to the preset slope. The ammonia fuel injection pressure and pulse width are increased to the target values ​​in the corresponding Map according to the preset slope, and the injection timing is based on the Map target value. After the target ammonia fuel injection pulse width reaches the target value in the corresponding Map, proceed to step S105.

[0082] Step S105: Continuously determine the actual ammonia fuel injection quantity for 10 seconds, and determine whether the error of the ratio between the actual ammonia fuel injection quantity and the target ammonia fuel injection quantity is always less than or equal to ±2%. If the determination is successful, proceed to step S106; otherwise, proceed to step S107.

[0083] Step S106: Mode switching successful, combustion mode output "dual fuel mode";

[0084] Step S107: The combustion mode outputs "ammonia to diesel mode" and proceeds to step S108;

[0085] Step S108: Maintain closed-loop control of engine speed and adjust diesel injection pulse width. Increase the positive feedforward increment of injection pulse width. This increment is determined by the ratio of the calorific value of the two fuels, namely ammonia fuel injection pulse width and its slope. Adjust diesel injection pressure and timing to the corresponding target values ​​in Map under pure diesel mode according to the preset slope. Decrease ammonia fuel injection pressure and pulse width according to the preset slope, and adjust injection timing according to Map.

[0086] Step S109: Determine whether the error between the diesel injection quantity and the target value in pure diesel mode within 2 seconds is less than or equal to 2%. If the determination is unsuccessful, return to step S107; if the determination is successful, proceed to step S110.

[0087] Step S110: Control the ammonia fuel injection valve to close, then return to step S102.

[0088] In this example embodiment, the method further includes:

[0089] The preset slope is positively correlated with the engine's operating load percentage and is calibrated and generated based on the engine's actual operating state.

[0090] In this example embodiment, the method further includes:

[0091] The actual ammonia fuel injection quantity is calculated based on the fuel injector parameters and the actual injection pressure and injection pulse width, or obtained by querying the preset ammonia fuel injector characteristic Map based on the actual parameters.

[0092] The target ammonia fuel injection quantity is calculated using the injection pressure, injection pulse width, and fuel injector parameters in the speed-load percentage map, or obtained by querying a preset ammonia fuel injector characteristic map based on relevant theoretical parameters.

[0093] In step S1300, when the dual-fuel engine is running in the dual-fuel mode of diesel and ammonia fuel, it can automatically switch to the pure diesel mode based on the second preset switching method.

[0094] In this example embodiment, the second preset switching method further includes:

[0095] Step S201: In "dual fuel mode", determine whether the engine load percentage falls within a reasonable range. If the engine load percentage falls within the preset range, proceed to step S202. If the engine load percentage does not fall within the preset range, proceed to step S203.

[0096] Step S202: Keep the dual-fuel mode unchanged and output "dual-fuel mode" in the combustion mode;

[0097] Step S203: Determine whether the load percentage is less than the lower limit of the preset range. If yes, proceed to step S205; otherwise, proceed to step S204.

[0098] Step S204: Determine whether the load exceeds the preset upper limit within 1 second. If not, return to step S202; if yes, proceed to step 205.

[0099] Step S205: Switch the combustion mode and output "ammonia to diesel mode", and proceed to step S206;

[0100] Step S206: Adjust the diesel injection pulse width to perform closed-loop control of the engine speed. The injection pulse width is increased by a positive feedforward increment, which is determined by the ratio of the calorific value of the two fuels, namely the ammonia fuel injection pulse width and its slope. The diesel injection pressure and timing are adjusted to the corresponding target values ​​in Map under pure diesel mode according to the preset slope. Under the "ammonia to diesel mode", the ammonia fuel injection pressure and pulse width are reduced according to the preset slope.

[0101] Step S207: Determine whether the error between the diesel injection quantity and the target value in pure diesel mode within 2 seconds is less than or equal to 2%. If not, return to step S206; if yes, proceed to step S208.

[0102] Step S208: Control the ammonia fuel injection valve to close, and output the combustion mode as "pure diesel mode".

[0103] In this example embodiment, the method further includes:

[0104] The preset range is 15% ≤ load percentage ≤ 103%.

[0105] In step S1400, when the dual-fuel engine is running in the dual-fuel mode of diesel and ammonia fuel, it can be manually switched to the pure diesel mode based on the third preset switching method.

[0106] In this example embodiment, the third preset switching method further includes:

[0107] Step S301: In "dual fuel mode", a switching command is manually issued, and the combustion mode output is "ammonia to diesel mode";

[0108] Step S302: Adjust the diesel injection pulse width to perform closed-loop control of the engine speed. Increase the positive feedforward increment of the injection pulse width. The increment is determined by the ratio of the calorific value of the two fuels, namely the ammonia fuel injection pulse width and its slope. Adjust the diesel injection pressure and timing to the corresponding target values ​​in Map under pure diesel mode according to the preset slope. Decrease the ammonia fuel injection pressure and pulse width according to the preset slope.

[0109] Step S303: Check whether the error between the diesel injection quantity and the target value in pure diesel mode within 2 seconds is less than or equal to 2%. If not, return to step S302; if yes, proceed to step S304.

[0110] Step S304: Control the ammonia fuel injection valve to close, and output the combustion mode as "pure diesel mode".

[0111] Example 2:

[0112] In the embodiments of this example, this disclosure includes a control method for an engine in pure diesel mode, dual-fuel mode and several transition modes, specifically including the following three parts: a control method for manually switching from pure diesel mode to dual-fuel mode, a control method for manually switching from dual-fuel mode to pure diesel mode, and a control method for automatically switching from dual-fuel mode to pure diesel mode.

[0113] In this example embodiment, the pure diesel mode refers to a working mode in which ammonia fuel does not enter the cylinder and does not participate in engine combustion, but only diesel fuel is injected by the in-cylinder diesel injector for combustion and power generation. The amount of diesel fuel injected is determined by the engine speed regulation and load characteristics.

[0114] In this example embodiment, the dual-fuel mode refers to a mode in which a certain amount of ammonia fuel enters the cylinder in a certain form, while a certain amount of diesel fuel is injected into the cylinder, and the diesel fuel ignites the ammonia gas to perform work.

[0115] In this example embodiment, the transition modes include a diesel-to-ammonia mode and an ammonia-to-diesel mode. The diesel-to-ammonia mode refers to the transition phase from a pure diesel mode to a dual-fuel mode; the ammonia-to-diesel mode refers to the transition phase from a dual-fuel mode to a pure diesel mode.

[0116] In the embodiments of this example, the "certain form" includes multiple technical solutions for ammonia fuel entering the cylinder, specifically ammonia fuel port injection, ammonia fuel low-pressure direct injection in the cylinder, and ammonia fuel high-pressure direct injection in the cylinder. It should be clear that the control method described in this disclosure does not involve specific solutions for ammonia fuel entering the cylinder. Therefore, including the above three ammonia fuel injection solutions and other solutions for ammonia fuel entering the cylinder should not limit the scope of protection of this disclosure.

[0117] In the embodiments of this example, the certain amount of diesel and ammonia fuel refers to the fact that the two fuels participate in engine combustion in any proportion under the condition of simultaneous application, which should not limit the scope of protection of this disclosure.

[0118] In this example embodiment, "simultaneous" refers to synchronization within a certain time scale, not strictly the same injection moment or ignition moment. Specifically, the application of two fuels within the same engine cycle falls within the scope of this description; the order and time interval between ammonia fuel and diesel fuel entering the cylinder and participating in combustion should not limit the scope of protection of this disclosure.

[0119] The manual switching mode refers to the process where, under certain conditions, the engine operator issues a command to adjust the engine's operating mode. These conditions include a series of engine operating parameters, such as engine speed, load, and fuel pre-supply, being within preset ranges.

[0120] The automatic switching mode refers to the engine control system automatically issuing a command to adjust the engine operating mode when certain conditions are met.

[0121] During the start-up phase, idling phase, and low-load operation phase, the engine operates in pure diesel mode.

[0122] The starting phase includes starting from a stopped state and acceleration phases; the idling phase is the phase in which the engine speed is accelerated to the idle speed and runs smoothly; the rated speed running phase is the phase in which the engine speed is increased to the rated speed and runs smoothly under a small load.

[0123] The starting speed, idle speed, and rated speed mentioned are engine calibration parameters.

[0124] In the embodiments of this example, as Figure 2A As shown, the switching from pure diesel mode to dual-fuel mode includes the following steps:

[0125] S100: Issue a switching command.

[0126] S101: Determine if the engine load percentage is between 20% and 100%. If not, proceed to step S102; otherwise, proceed to step S103.

[0127] The load percentage is calculated as follows: Load percentage = Actual engine load / Rated load × 100%

[0128] In this example embodiment, the 20% load percentage is determined by the characteristics of ammonia fuel. At loads of 20% and below, the mixing and combustion process of ammonia fuel suffers from slow combustion rate, low thermal efficiency, and excessively high exhaust temperature. Therefore, dual-fuel mode is not suitable, and pure diesel mode should be used instead.

[0129] Step S102: The combustion mode output is "pure diesel mode", and the output switching failure prompt / alarm is displayed.

[0130] Step S103: The combustion mode outputs "diesel to ammonia mode", indicating that the engine is in the transition stage of switching from diesel to dual fuel, and then proceeds to step S104.

[0131] Step S104: In "diesel-to-ammonia mode", the engine speed is controlled in a closed loop by adjusting the diesel injection pulse width. The injection pulse width is increased by a feedforward increment (negative value), which is determined by the ammonia fuel injection pulse width and its slope, as well as the calorific value ratio of the two fuels. The diesel injection pressure and timing are adjusted to the target values ​​in the diesel injection map of the dual-fuel mode according to a certain slope. The ammonia fuel injection pressure and pulse width are increased to the target values ​​in the corresponding map according to a certain slope, and the injection timing is adjusted to the target value in the map. After the target ammonia fuel injection pulse width reaches the target value in the corresponding map, proceed to step S105.

[0132] The slope is related to the percentage of engine load and needs to be calibrated according to the actual operating conditions of the engine.

[0133] Step S105: The actual ammonia fuel injection quantity is continuously judged for 10 seconds. The judgment is whether the error in the ratio of the actual ammonia fuel injection quantity to the target ammonia fuel injection quantity is always less than or equal to a certain value. In some application cases, the error control range is within ±2%.

[0134] If the determination is successful, proceed to step S106. Otherwise, proceed to step S107.

[0135] In this example embodiment, the characteristics of ammonia fuel determine that it exhibits significant changes in physical properties under different injection conditions, which is distinct from other alternative fuels. Therefore, the monitoring and calculation of the injection quantity should be carried out over a relatively long period of time to improve the accuracy of the calculation.

[0136] Step S106: Mode switching successful, combustion mode output "dual fuel mode";

[0137] Step S107: The combustion mode output is "Ammonia to Diesel Mode". Then proceed to step S108.

[0138] The actual ammonia fuel injection quantity is calculated based on the fuel injector parameters and the actual injection pressure and injection pulse width, or obtained by querying the ammonia fuel injector characteristic map based on the actual parameters.

[0139] The target ammonia fuel injection quantity is calculated using the injection pressure, injection pulse width, and fuel injector parameters in the speed-load percentage map, or obtained by querying the ammonia fuel injector characteristic map based on relevant theoretical parameters.

[0140] Step S108: Maintain closed-loop control of engine speed and adjust diesel injection pulse width. Increase the feedforward increment (positive value) of injection pulse width. This increment is determined by the ratio of the calorific value of the two fuels, namely ammonia fuel injection pulse width and its slope. Adjust diesel injection pressure and timing to the corresponding target values ​​in Map under pure diesel mode according to a certain slope. Decrease ammonia fuel injection pressure and pulse width according to a certain slope, and adjust injection timing according to Map.

[0141] Step S109: Determine whether the error between the diesel injection quantity and the target value in pure diesel mode within 2 seconds is less than or equal to 2%. If the determination fails, return to step S107; if the determination succeeds, proceed to step S110.

[0142] Step S110: Close the ammonia fuel injection valve and return to step S102.

[0143] The diesel injection quantity and the target value in pure diesel mode are calculated based on diesel injection pressure, pulse width and injector-related parameters, respectively, and the same applies below.

[0144] In the embodiments of this example, as Figure 2B As shown, in "Dual Fuel Mode", the automatic switching mode enable is always on. The switching process and control method are as follows:

[0145] Step S201: In "dual-fuel mode", determine whether the engine load percentage falls within a reasonable range. In some applications, the reasonable range is 15% ≤ load percentage ≤ 103%. If the engine load percentage falls within the reasonable range, proceed to step S202; if the engine load percentage does not fall within the reasonable range, proceed to step S203.

[0146] Step S202: Keep the dual-fuel mode unchanged and output "dual-fuel mode" in the combustion mode.

[0147] In this example embodiment, the lower limit of the reasonable range should be slightly lower than the lower limit of the percentage of compliance for manually switching to dual-fuel mode in pure diesel mode, which is 20% in the application case described above;

[0148] In this example embodiment, the upper limit of the reasonable range should be slightly higher than the engine's rated load percentage, which is 100% load.

[0149] In the embodiments of this example, the reasonable range may vary to some extent on different engines and under different performance requirements, and the scope of protection of this disclosure should not be limited by the specific numerical value of the reasonable range.

[0150] Step S203: Determine whether the load percentage is less than 15%. If yes, proceed to step S205; otherwise, proceed to step S204.

[0151] Step S204: Determine whether the load is greater than 103% for 1 second. If not, return to step S202; if so, proceed to step 205.

[0152] Step S205: Switch the combustion mode and output "ammonia to diesel mode", and proceed to step S206.

[0153] Step S206: Adjust the diesel injection pulse width to perform closed-loop control of the engine speed. Increase the feedforward increment (positive value) of the injection pulse width. This increment is determined by the ratio of the calorific value of the two fuels, namely the ammonia fuel injection pulse width and its slope. Adjust the diesel injection pressure and timing to the corresponding target values ​​in Map under pure diesel mode according to a certain slope. Under the "ammonia to diesel mode", the ammonia fuel injection pressure and pulse width decrease according to a certain slope.

[0154] Step S207: Determine whether the error between the diesel injection quantity and the target value in pure diesel mode within 2 seconds is less than or equal to 2%. If not, return to step S206; if yes, proceed to step S208.

[0155] Step S208: Control the ammonia fuel injection valve to close, and output the combustion mode as "pure diesel mode".

[0156] In the embodiments of this example, as Figure 2C As shown, in "dual-fuel mode," manual switching to pure diesel mode is allowed without determining the load percentage. The switching process and control method are as follows:

[0157] Step S301: In "dual fuel mode", a switching command is manually issued, and the combustion mode output is "ammonia to diesel mode";

[0158] Step S302: Adjust the diesel injection pulse width to perform closed-loop control of the engine speed. Increase the feedforward increment (positive value) of the injection pulse width. This increment is determined by the ratio of the calorific value of the two fuels, namely the ammonia fuel injection pulse width and its slope. Adjust the diesel injection pressure and timing to the corresponding target values ​​in Map under pure diesel mode according to a certain slope. Decrease the ammonia fuel injection pressure and pulse width according to a certain slope.

[0159] Step S303: Check if the error between the diesel injection quantity and the target value in pure diesel mode within 2 seconds is less than or equal to 2%. If not, return to step S302; if yes, proceed to step S304.

[0160] Step S304: Control the ammonia fuel injection valve to close, and output the combustion mode as "pure diesel mode".

[0161] Example 3:

[0162] In this example embodiment, the dual-fuel engine (diesel and ammonia fuel) operates in pure diesel mode from shutdown to startup, without supplying ammonia fuel; the diesel injection pressure and timing are set according to the pure diesel mode Map target value, and the diesel injection pulse width is controlled by speed PID closed-loop control.

[0163] In this example embodiment, the diesel and ammonia dual-fuel engine operates in pure diesel mode without supplying ammonia fuel when the load percentage is less than 20%. The diesel injection pressure and timing are set according to the target values ​​of the pure diesel mode Map, and the diesel injection pulse width is controlled by a speed PID closed-loop control. When the load percentage is less than 20%, if manual switching to dual-fuel mode is selected, a switching failure message will be displayed, and the engine will continue to operate in pure diesel mode.

[0164] In this example embodiment, when the diesel and ammonia dual-fuel engine is running at a load percentage greater than or equal to 20% and less than or equal to 100%, it can be manually switched from the pure diesel mode to the dual-fuel mode. The switching process and control method are as follows:

[0165] The combustion mode output is "diesel to ammonia mode". The diesel injection pressure and timing are adjusted to the target value of Map in dual-fuel mode according to a certain slope. The ammonia fuel injection pressure and pulse width are increased to the target value of Map in dual-fuel mode according to a certain slope. The injection timing is set according to Map. The diesel injection pulse width is controlled by feedforward plus speed PID closed loop control.

[0166] Within 10 seconds, determine if the error between the actual fuel injection quantity and the target fuel injection quantity is less than or equal to 2%. If yes, output "Dual Fuel Mode" for combustion mode, indicating successful mode switching. If not, output "Ammonia to Diesel Mode" for combustion mode, and adjust diesel injection pressure and timing to the pure diesel mode's Map value at a certain slope; reduce ammonia fuel injection pressure and pulse width to 0 at a certain slope. Then, within 2 seconds, determine if the error between the diesel injection quantity and the corresponding injection quantity in the pure diesel mode is less than or equal to 2%. If not, return to the previous step; if yes, close the ammonia fuel injection valve, stop ammonia fuel supply, output "Pure Diesel Mode" for combustion mode, and output a switching failure prompt / alarm.

[0167] When the diesel and ammonia fuel dual-fuel engine is running in the dual-fuel mode, the automatic switch to the pure diesel mode is enabled. During operation, it continuously judges whether the current load percentage is greater than or equal to 15% and less than or equal to 103%. If so, it maintains the dual-fuel mode. If not, it first judges whether the load percentage is less than 15%. If so, it outputs the combustion mode as "ammonia to diesel mode". If not, it further judges whether the load is greater than 103% for 1 second. If not, it maintains the dual-fuel mode. If so, it outputs the combustion mode as "ammonia to diesel mode".

[0168] When the combustion mode is "ammonia to diesel mode", the following control process is performed: the diesel injection pressure and timing are adjusted to the Map target value of the pure diesel mode at a certain slope; the ammonia fuel injection pressure and pulse width are reduced to 0 at a certain slope, and the injection timing is set to the Map value; the diesel injection pulse width is controlled by a feedforward plus speed PID closed loop control. Then, it is determined whether the error between the diesel injection quantity and the corresponding injection quantity of the pure diesel mode is less than or equal to 2% within 2 seconds. If not, the process returns to the previous step; if so, the ammonia fuel injection valve is closed, the ammonia fuel supply is stopped, and the combustion mode is output as "pure diesel mode".

[0169] When the diesel and ammonia dual-fuel engine is running in the dual-fuel mode, it can be manually switched to pure diesel mode at any time. The switching process and control method are as follows:

[0170] The operator issues a switching command, and the combustion mode outputs "ammonia to diesel mode".

[0171] When the combustion mode is "ammonia to diesel mode", the following control process is performed: the diesel injection pressure and timing are adjusted to the Map target value of the pure diesel mode at a certain slope; the ammonia fuel injection pressure and pulse width are reduced to 0 at a certain slope, and the injection timing is set to the Map value; the diesel injection pulse width is controlled by a feedforward plus speed PID closed loop control. Then, it is determined whether the error between the diesel injection quantity and the corresponding injection quantity of the pure diesel mode is less than or equal to 2% within 2 seconds. If not, the process returns to the previous step; if so, the ammonia fuel injection valve is closed, the ammonia fuel supply is stopped, and the combustion mode is output as "pure diesel mode".

[0172] In this example embodiment, the beneficial effects of the technical solution of this disclosure are:

[0173] 1. This disclosure proposes a control method for the operation modes of diesel and ammonia fuel engines and the switching process between them. The key focus is on determining the preconditions for switching. Specifically, manually switching from pure diesel mode to dual-fuel mode requires the engine load percentage to be between 20% and 100%, meaning the engine is only suitable for dual-fuel mode operation within a certain load percentage range. Automatic switching from dual-fuel mode to pure diesel mode requires the engine load to be less than 15% or greater than 103% for one second. That is, if the load percentage drops below the critical point, or the load exceeds the range and exceeds the transient threshold, automatic switching to pure diesel mode is initiated to protect the engine. The determination of these conditions is based on the fuel characteristics of ammonia to ensure the high efficiency, safety, and reliability of the engine operating in dual-fuel mode.

[0174] 2. During the switching process, engine speed control employs feedforward correction of injection pulse width combined with closed-loop speed control. The feedforward pulse width increment (decrease) is related to the slope of the target ammonia fuel supply and the ratio of the two fuel calorific values, ensuring rapid adjustment within a certain range of the theoretical calorific value and improving engine stability during switching. Existing technologies include basic control concepts for diesel and ammonia fuels and their operating modes, such as using pure diesel mode during startup and low loads, and employing different fuel supply ratios for different load percentages. However, they do not provide detailed control methods and corresponding procedures for maintaining engine stability, which differs significantly from the core method of this disclosure. No relevant reports have been found in this disclosure regarding the application of ammonia fuel in marine engines.

[0175] 3. This disclosure determines the success of the mode switch by assessing whether the actual and target ammonia fuel injection quantities are less than or equal to 2% within 10 seconds after switching from pure diesel mode to dual-fuel mode; and whether the error between the diesel fuel injection quantity and the target value in pure diesel mode is less than or equal to 2% during the switch from dual-fuel mode to pure diesel mode. The timing requirements for ammonia fuel injection quantity are higher and more stringent, unlike other alternative fuels, and are based on the physical characteristics of ammonia fuel. The purpose of these determinations is to ensure a complete engine mode switch.

[0176] It should be noted that although the steps of the method in this disclosure are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in that specific order, or that all the steps shown must be performed to achieve the desired result. Additional or alternative steps may be omitted, multiple steps may be combined into one step, and / or a step may be broken down into multiple steps.

[0177] Furthermore, in this exemplary embodiment, a mode control device for a diesel and ammonia dual-fuel engine is also provided. (See reference...) Figure 3 As shown, the mode control device 300 for a diesel and ammonia dual-fuel engine may include: a pure diesel operation module 310, a first switching module 320, a second switching module 330, and a third switching module 340. Wherein:

[0178] The pure diesel operation module 310 is used to operate the dual-fuel diesel and ammonia engine in pure diesel mode during the start-up process from the shutdown state, and under the condition that the load percentage is less than 20%, without supplying ammonia fuel; the diesel injection pressure and timing are set according to the target value of the pure diesel mode Map, and the diesel injection pulse width is controlled by the speed PID closed loop.

[0179] The first switching module 320 is used to switch the diesel and ammonia fuel dual-fuel engine from the pure diesel mode to the dual-fuel mode based on the first preset switching method when the load percentage is greater than or equal to 20% and less than or equal to 100%.

[0180] The second switching module 330 is used to automatically switch to the pure diesel mode based on a second preset switching method when the diesel and ammonia fuel dual-fuel engine is running in the dual-fuel mode.

[0181] The third switching module 340 is used to manually switch to the pure diesel mode based on a third preset switching method when the diesel and ammonia fuel dual-fuel engine is running in the dual-fuel mode.

[0182] The specific details of the mode control device module for each of the aforementioned diesel and ammonia dual-fuel engines have been described in detail in the corresponding mode control method for diesel and ammonia dual-fuel engines, and therefore will not be repeated here.

[0183] It should be noted that although several modules or units of a mode control device 300 for a diesel and ammonia dual-fuel engine have been mentioned in the detailed description above, this division is not mandatory. In fact, according to embodiments of this disclosure, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0184] Furthermore, in an exemplary embodiment of this disclosure, an electronic device capable of implementing the above-described method is also provided.

[0185] Those skilled in the art will understand that various aspects of this disclosure can be implemented as a system, method, or program product. Therefore, various aspects of this disclosure can be embodied in the following forms: a completely hardware embodiment, a completely software embodiment (including firmware, microcode, etc.), or an embodiment combining hardware and software aspects, collectively referred to herein as a "circuit," "module," or "system."

[0186] The following reference Figure 4 To describe an electronic device 400 according to such an embodiment of the present disclosure. Figure 4 The electronic device 400 shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments disclosed herein.

[0187] like Figure 4As shown, the electronic device 400 is manifested in the form of a general-purpose computing device. The components of the electronic device 400 may include, but are not limited to: at least one processing unit 410, at least one storage unit 420, a bus 430 connecting different system components (including storage unit 420 and processing unit 410), and a display unit 440.

[0188] The storage unit stores program code that can be executed by the processing unit 410, causing the processing unit 410 to perform the steps described in the "Exemplary Methods" section of this specification according to various exemplary embodiments of this disclosure. For example, the processing unit 410 can perform actions such as... Figure 1 Steps S1100 to S1400 are shown in the diagram.

[0189] Storage unit 420 may include a readable medium in the form of a volatile storage unit, such as random access memory (RAM) 4201 and / or cache memory 4202, and may further include a read-only memory (ROM) 4203.

[0190] Storage unit 420 may also include a program / utility 4204 having a set (at least one) program module 4205, such program module 4205 including but not limited to: operating system, one or more application programs, other program modules and program data, each or some combination of these examples may include an implementation of a network environment.

[0191] Bus 430 can represent one or more of several types of bus structures, including a memory cell bus or memory cell controller, a peripheral bus, a graphics acceleration port, a processing unit, or a local bus using any of the various bus structures.

[0192] Electronic device 400 can also communicate with one or more external devices 470 (e.g., keyboard, pointing device, Bluetooth device, etc.), and with one or more devices that enable a user to interact with electronic device 400, and / or with any device that enables electronic device 400 to communicate with one or more other computing devices (e.g., router, modem, etc.). This communication can be performed via input / output (I / O) interface 450. Furthermore, electronic device 400 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) via network adapter 460. As shown, network adapter 460 communicates with other modules of electronic device 400 via bus 430. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with electronic device 400, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0193] From the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of this disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) or on a network, including several instructions to cause a computing device (such as a personal computer, server, terminal device, or network device, etc.) to execute the methods according to the embodiments of this disclosure.

[0194] In exemplary embodiments of this disclosure, a computer-readable storage medium is also provided, on which a program product capable of implementing the methods described above is stored. In some possible embodiments, various aspects of this disclosure may also be implemented as a program product including program code that, when the program product is run on a terminal device, causes the terminal device to perform the steps described in the "Exemplary Methods" section of this specification according to various exemplary embodiments of this disclosure.

[0195] refer to Figure 5 As shown, a program product 500 for implementing the above-described method according to an embodiment of the present disclosure is described. This product may employ a portable compact disc read-only memory (CD-ROM) and include program code, and may run on a terminal device, such as a personal computer. However, the program product of the present disclosure is not limited thereto. In this document, a readable storage medium may be any tangible medium containing or storing a program that may be used by or in conjunction with an instruction execution system, apparatus, or device.

[0196] The program product may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0197] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable signal medium may also be any readable medium other than a readable storage medium, capable of sending, propagating, or transmitting programs for use by or in conjunction with an instruction execution system, apparatus, or device.

[0198] The program code contained on the readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof.

[0199] Program code for performing the operations of this disclosure can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, and conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0200] Furthermore, the above figures are merely illustrative of the processes included in the method according to exemplary embodiments of this disclosure and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Additionally, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0201] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the claims.

[0202] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

[0203] The above are preferred embodiments of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A mode control method for a diesel and ammonia dual-fuel engine, characterized in that, The method includes: The dual-fuel diesel and ammonia engine operates in pure diesel mode from the shutdown state to the start-up process, and under the condition that the load percentage is less than 20%, without supplying ammonia fuel; the diesel injection pressure and timing are set according to the target values ​​of the pure diesel mode Map, and the diesel injection pulse width is controlled by the speed PID closed loop. When the diesel and ammonia fuel dual-fuel engine is running under the condition of a load percentage greater than or equal to 20% and less than or equal to 100%, it switches from the pure diesel mode to the dual-fuel mode based on the first preset switching method. When the diesel and ammonia fuel dual-fuel engine is running in dual-fuel mode, it automatically switches to pure diesel mode based on a second preset switching method. The second preset switching method further includes: Step S201: In "dual-fuel mode," determining whether the engine load percentage falls within a reasonable range. If the engine load percentage falls within a preset range, proceed to step S202; if the engine load percentage does not fall within the preset range, proceed to step S203. Step S202: Maintain the dual-fuel mode without switching, and output "dual-fuel mode" in the combustion mode. Step S203: Determine whether the load percentage is less than the lower limit of a preset range. If yes, proceed to step S205; otherwise... Then proceed to step S204; Step S204: Determine whether the load exceeds the upper limit of the preset range for 1 second. If not, return to step S202; if yes, proceed to step S205; Step S205: Switch the combustion mode and output "ammonia to diesel mode", and proceed to step S206; Step S206: Adjust the diesel injection pulse width to perform closed-loop control of the speed. The injection pulse width is increased by a positive feedforward increment, which is determined by the ammonia fuel injection pulse width and its slope and the calorific value ratio of the two fuels; The diesel injection pressure and timing are adjusted to the corresponding target values ​​in Map under the pure diesel mode according to the preset slope; Under the "ammonia to diesel mode", the ammonia fuel injection pressure and pulse width are reduced according to the preset slope; Step S207: Determine whether the error between the diesel injection quantity and the target value under the pure diesel mode is less than or equal to 2% within 2 seconds. If not, return to step S206; if yes, proceed to step S208; Step S208: Control the ammonia fuel injection valve to close, and output the combustion mode as "pure diesel mode"; The third preset switching method further includes: when the diesel and ammonia fuel dual-fuel engine is running in the dual-fuel mode, manually switching to the pure diesel mode based on the third preset switching method; Step S301: In the "dual-fuel mode", a switching command is manually issued, and the combustion mode outputs "ammonia to diesel mode"; Step S302: The diesel injection pulse width is adjusted to perform closed-loop control of the engine speed, and the injection pulse width is increased by a positive feedforward increment, the increment being determined by the ammonia fuel injection pulse width and its slope and the calorific value ratio of the two fuels; the diesel injection pressure and timing are adjusted to the corresponding target values ​​in Map in the pure diesel mode according to the preset slope; the ammonia fuel injection pressure and pulse width are reduced according to the preset slope; Step S303: Whether the error between the diesel injection quantity and the target value in the pure diesel mode is less than or equal to 2% within 2 seconds, if not, return to step S302; if yes, proceed to step S304; Step S304: Control the ammonia fuel injection valve to close, and the combustion mode outputs "pure diesel mode".

2. The mode control method for a diesel and ammonia dual-fuel engine as described in claim 1, characterized in that, The first preset switching method in the method further includes: Step S100: Receive a switching command from the user to switch from the pure diesel mode to the dual-fuel mode; Step S101: Determine whether the engine load percentage is between 20% and 100%. If not, proceed to step S102; if yes, proceed to step S103. Step S102: The combustion mode output is "pure diesel mode", and a switching failure prompt / alarm signal is output; Step S103: The combustion mode outputs "diesel to ammonia mode", indicating that the engine is in the transition stage of switching from diesel to dual fuel, and then proceeds to step S104. Step S104: In "diesel-to-ammonia mode", the engine speed is controlled in a closed loop by adjusting the diesel injection pulse width. The injection pulse width is increased by a negative feedforward increment, which is determined by the ammonia fuel injection pulse width and its slope and the calorific value ratio of the two fuels. The diesel injection pressure and timing are adjusted to the target values ​​in the diesel injection Map of the dual-fuel mode according to the preset slope. The ammonia fuel injection pressure and pulse width are increased to the target values ​​in the corresponding Map according to the preset slope, and the injection timing is based on the Map target value. After the target ammonia fuel injection pulse width reaches the target value in the corresponding Map, proceed to step S105. Step S105: Continuously determine the actual ammonia fuel injection quantity for 10 seconds, and determine whether the error of the ratio between the actual ammonia fuel injection quantity and the target ammonia fuel injection quantity is always less than or equal to ±2%. If the determination is successful, proceed to step S106; otherwise, proceed to step S107. Step S106: Mode switching successful, combustion mode output "dual fuel mode"; Step S107: The combustion mode outputs "ammonia to diesel mode" and proceeds to step S108; Step S108: Maintain closed-loop control of engine speed and adjust diesel injection pulse width. Increase the positive feedforward increment of injection pulse width. This increment is determined by the ammonia fuel injection pulse width and its slope and the calorific value ratio of the two fuels. Adjust diesel injection pressure and timing to the corresponding target values ​​in Map under pure diesel mode according to the preset slope. Decrease ammonia fuel injection pressure and pulse width according to the preset slope, and adjust injection timing according to Map. Step S109: Determine whether the error between the diesel injection quantity and the target value in pure diesel mode within 2 seconds is less than or equal to 2%. If the determination is unsuccessful, return to step S107; if the determination is successful, proceed to step S110. Step S110: Control the ammonia fuel injection valve to close, then return to step S102.

3. The mode control method for a diesel and ammonia dual-fuel engine as described in claim 2, characterized in that, The method further includes: The preset slope is positively correlated with the engine's operating load percentage and is calibrated and generated based on the engine's actual operating state.

4. The mode control method for a diesel and ammonia dual-fuel engine as described in claim 2, characterized in that, The method further includes: The actual ammonia fuel injection quantity is calculated based on the fuel injector parameters and the actual injection pressure and injection pulse width, or obtained by querying the preset ammonia fuel injector characteristic Map based on the actual parameters. The target ammonia fuel injection quantity is calculated using the injection pressure, injection pulse width, and fuel injector parameters in the speed-load percentage map, or obtained by querying a preset ammonia fuel injector characteristic map based on relevant theoretical parameters.

5. The mode control method for a diesel and ammonia dual-fuel engine as described in claim 1, characterized in that, The method further includes: The preset range is 15% ≤ load percentage ≤ 103%.

6. A mode control device for a diesel and ammonia dual-fuel engine, characterized in that, For implementing the mode control method of the diesel and ammonia dual-fuel engine according to claim 1, the apparatus comprises: The pure diesel operation module is used to operate the dual-fuel diesel and ammonia engine in pure diesel mode during the start-up process from the shutdown state, and under the condition that the load percentage is less than 20%, without supplying ammonia fuel; the diesel injection pressure and timing are set according to the target values ​​of the pure diesel mode Map, and the diesel injection pulse width is controlled by the speed PID closed loop; The first switching module is used to switch the diesel and ammonia fuel dual-fuel engine from pure diesel mode to dual-fuel mode based on a first preset switching method when the load percentage is greater than or equal to 20% and less than or equal to 100%. The second switching module is used to automatically switch to the pure diesel mode based on a second preset switching method when the diesel and ammonia fuel dual-fuel engine is running in the dual-fuel mode. The third switching module is used to manually switch to the pure diesel mode based on a third preset switching method when the diesel and ammonia fuel dual-fuel engine is running in the dual-fuel mode.

7. An electronic device, characterized in that, include Processor; and A memory storing computer-readable instructions that, when executed by the processor, implement the method according to any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that, It stores a computer program that, when executed by a processor, implements the method according to any one of claims 1 to 5.

Images