Dual fuel engine and misfire fault diagnosis method and device

Abstract

This invention discloses a dual-fuel engine and a method and apparatus for diagnosing misfire faults. The method includes: acquiring the exhaust temperature of each cylinder in real time; determining whether any cylinder is a misfire cylinder based on the current exhaust temperature of any cylinder and a preset misfire condition; if so, determining a corresponding diagnostic process based on the relationship between the misfire temperature of the misfire cylinder and a first preset value and a second preset value, wherein the first preset value is greater than the second preset value; when the misfire temperature of the misfire cylinder is greater than the first preset value, the diagnostic process includes: controlling the engine to switch from an alternative fuel mode to a diesel mode, and determining whether the current exhaust temperature of the misfire cylinder still meets the preset misfire condition; if so, generating a prompt message to stop and check the diesel injector of the misfire cylinder; if not, controlling the engine based on the acquired execution command to achieve automatic diagnosis.

Description

Technical Field

[0001] This invention relates to the field of engines, and more particularly to a dual-fuel engine and a method and apparatus for diagnosing misfire faults. Background Technology

[0002] When natural gas, ammonia, methanol (hereinafter referred to as alternative fuels) are used as fuels in large-bore engines, diesel fuel is generally used as the ignition source due to their high flash point. This type of dual-fuel engine can operate in diesel mode using diesel fuel alone, or it can use a small amount of diesel fuel to ignite alternative fuels and operate in alternative fuel mode. Therefore, this type of dual-fuel engine has both diesel injectors and alternative fuel injectors.

[0003] Dual-fuel engines operating in alternative fuel mode require both diesel injectors and alternative fuel injectors to work together. Furthermore, they incorporate the characteristics of different alternative fuels. For example, ammonia is difficult to ignite and is corrosive, methanol is also corrosive, and natural gas presents challenges in real-time air-fuel ratio control due to variations in composition and operating conditions. These complex factors contribute to misfires, a common malfunction in dual-fuel engines. This manifests as a sudden drop in exhaust temperature in one cylinder when the engine is operating in alternative fuel mode. Misfires can lead to reduced engine power, increased fuel consumption, and worsened emissions.

[0004] Currently, the handling of misfires in dual-fuel engines involves manual troubleshooting, relying on professional engineers to go to the site to determine the cause of the malfunction and inspect each component one by one. This verification method is time-consuming and labor-intensive. Summary of the Invention

[0005] This invention proposes a method and apparatus for diagnosing misfires in dual-fuel engines. It does not rely on manual troubleshooting and can automatically diagnose misfires in dual-fuel engines, accurately determine the cause of misfires, improve fault diagnosis efficiency, and save time and costs.

[0006] Based on this, one embodiment of the present invention proposes a method for diagnosing misfire faults in a dual-fuel engine, including: Real-time acquisition of exhaust temperature for each cylinder; Based on the current exhaust temperature of any cylinder and the preset misfire conditions, determine whether any cylinder is a misfire cylinder. If so, determine the corresponding diagnostic process based on the relationship between the misfire temperature of the misfire cylinder and the first preset value and the second preset value, wherein the first preset value is greater than the second preset value. When the misfire temperature of the misfire cylinder is greater than the first preset value, the diagnostic process is as follows: the first diagnostic process includes controlling the engine to switch from alternative fuel mode to diesel mode, and determining whether the current exhaust temperature of the misfire cylinder still meets the preset misfire condition. If yes, a prompt message is generated to stop and check the diesel injector of the misfire cylinder. If no, the engine is controlled based on the obtained execution command, wherein the execution command is a first execution command or a second execution command. Under the first execution command, the engine is controlled to continue running in the diesel mode. Under the second execution command, the engine is continued to be diagnosed.

[0007] Optionally, the execution instruction is the second execution instruction, and controlling the engine based on the acquired execution instruction includes: Generate an interactive message on whether to unload the engine based on the second execution instruction; Based on the acquired engine unloading command, the engine's target speed is controlled to reach the calibrated speed, and it is determined whether the engine's actual speed has reached the calibrated speed. If so, the engine is controlled to switch from the diesel mode to the alternative fuel mode. If not, a speed control fault prompt message is generated.

[0008] Optionally, after controlling the engine to switch from diesel mode to alternative fuel mode, the method further includes: Determine whether the current exhaust temperature of the misfire cylinder still meets the preset misfire condition. If yes, generate a prompt message for a faulty alternative fuel injector and a shutdown inspection of the misfire cylinder; otherwise, generate a prompt message for a shutdown inspection of the alternative fuel injector of the misfire cylinder.

[0009] Optionally, after generating a selection interaction message regarding whether to unload the engine based on the second execution instruction, the method further includes: Based on the acquired engine non-unload command, the engine is controlled to continue operating in the diesel mode.

[0010] Optionally, after the engine is switched from alternative fuel mode to diesel mode and the current exhaust temperature of the misfired cylinder does not meet the preset misfire condition, and before the engine is controlled based on the acquired execution command, the first diagnostic process further includes: Generate an interactive prompt message to select the instruction to be executed.

[0011] Optionally, when the misfire temperature of the misfire cylinder is less than or equal to the first preset value and greater than the second preset value, the diagnostic process is a second diagnostic process including: controlling the engine to switch from the alternative fuel mode to the diesel mode, and generating a prompt message to stop and check the diesel injector of the misfire cylinder.

[0012] Optionally, when the misfire temperature of the misfire cylinder is less than or equal to the second preset value, the diagnostic process is a third diagnostic process including: controlling the engine to switch from the alternative fuel mode to the diesel mode, and generating a prompt message to stop the engine and check the exhaust temperature sensor of the misfire cylinder.

[0013] Optionally, the preset misfire condition is that the current exhaust temperature of the misfire cylinder is less than the current average exhaust temperature of all cylinders, and the difference between the current average exhaust temperature and the current exhaust temperature of the misfire cylinder is greater than a preset threshold.

[0014] Based on this, a second aspect of the present invention provides a dual-fuel engine misfire fault diagnosis device, comprising: multiple exhaust temperature sensors, a controller, and an interaction module. Each exhaust temperature sensor is used to detect the exhaust temperature of each cylinder. The interaction module is used to output messages generated by the controller and to respond to user input operations. The controller is used to execute the dual-fuel engine misfire fault diagnosis method proposed in any embodiment of the present invention.

[0015] Based on this, a third aspect of the present invention provides a dual-fuel engine, including the dual-fuel engine misfire fault diagnosis device as described in the embodiments of the present invention.

[0016] In summary, the dual-fuel engine and its misfire fault diagnosis method and apparatus proposed in this embodiment of the invention include: acquiring the exhaust temperature of each cylinder in real time; determining whether any cylinder is a misfire cylinder based on the current exhaust temperature of any cylinder and a preset misfire condition; if so, determining a corresponding diagnostic process based on the relationship between the misfire temperature of the misfire cylinder and a first preset value and a second preset value, wherein the first preset value is greater than the second preset value; when the misfire temperature of the misfire cylinder is greater than the first preset value, the diagnostic process is as follows: the first diagnostic process includes: controlling the engine to switch from alternative fuel mode to diesel mode, and determining whether the current exhaust temperature of the misfire cylinder still meets the preset misfire condition; if so, generating a prompt message to stop and check the diesel injector of the misfire cylinder; if not, controlling the engine based on the acquired execution command, wherein the execution command is a first execution command or a second execution command; under the first execution command, controlling the engine to continue running in diesel mode; under the second execution command, continuing to diagnose the engine. Therefore, this invention does not rely on manual troubleshooting and can automatically diagnose misfire faults in dual-fuel engines, accurately determine the cause of misfire faults in dual-fuel engines, improve fault diagnosis efficiency, and save time and costs. Attached Figure Description

[0017] Figure 1 This is a flowchart of the dual-fuel engine misfire fault diagnosis method proposed in the embodiments of the present invention; Figure 2 This is a flowchart of another method for diagnosing misfires in a dual-fuel engine proposed in an embodiment of the present invention; Figure 3 This is a block diagram of the dual-fuel engine misfire fault diagnosis device proposed in an embodiment of the present invention. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the invention and not all structures. Various modifications and variations can be made to the present invention without departing from its spirit or scope, which will be apparent to those skilled in the art. Therefore, the present invention is intended to cover modifications and variations falling within the scope of the corresponding claims and their equivalents. It should be noted that the embodiments provided in the present invention can be combined with each other without contradiction.

[0019] In the existing solution, when the exhaust temperature of a certain cylinder of a dual-fuel engine operating in the alternative fuel mode is lower than the temperature limit value, an alarm is triggered. After the operator exits the alternative fuel mode and shuts down the engine, the exhaust temperature sensor and the monitoring channel, as well as components such as the alternative fuel injector and the diesel injector, are checked in sequence. If there is a problem, they are replaced. The present invention does not rely on manual troubleshooting, can automatically diagnose the misfire fault of the dual-fuel engine, accurately judge the cause of the misfire fault of the dual-fuel engine, improves the fault judgment efficiency, and saves time and costs. The specific technical solution is as follows: Figure 1 This is the flowchart of the misfire fault diagnosis method for a dual-fuel engine proposed in an embodiment of the present invention. As Figure 1 shown, the method includes: S101, obtain the exhaust temperature of each cylinder in real time.

[0020] Among them, the exhaust temperature of the cylinder can be obtained through an exhaust temperature sensor. Each cylinder is provided with a corresponding exhaust temperature sensor to collect the exhaust temperature of the corresponding cylinder.

[0021] S102, judge whether any cylinder is a misfiring cylinder according to the current exhaust temperature of any cylinder and the preset misfire condition.

[0022] It can be understood that when the cylinder burns and does work normally, enough heat will be released to drive the exhaust temperature to rise. When the cylinder misfires, normal combustion cannot be completed in the cylinder, the released heat is greatly reduced, and the corresponding exhaust temperature will also drop significantly. Therefore, judging the misfire state through the exhaust temperature has high accuracy and reliability. If it is judged that the cylinder is a misfiring cylinder, then enter the next step to match the corresponding diagnosis process. If it is not judged as a misfiring cylinder, then continue to maintain the current operating state and continuously monitor the exhaust temperature of each cylinder.

[0023] Among them, the preset misfire condition is set as the current exhaust temperature being lower than the set limit value. That is to say, when the current exhaust temperature of any cylinder is lower than the set limit value, it means that the cylinder is in a misfiring state. Exemplarily, the engine includes a first cylinder, a second cylinder, a third cylinder and a fourth cylinder, and a first exhaust temperature sensor, a second exhaust temperature sensor, a third exhaust temperature sensor and a fourth exhaust temperature sensor are respectively provided corresponding to them. Among them, the exhaust temperature collected by the first exhaust temperature sensor is T1, the exhaust temperature collected by the second exhaust temperature sensor is T2, the exhaust temperature collected by the third exhaust temperature sensor is T3, the exhaust temperature collected by the fourth exhaust temperature sensor is T4, and the set limit value is T. Then when T1<T, the first cylinder is a misfiring cylinder; when T2<T, the second cylinder is a misfiring cylinder; when T3<T, the third cylinder is a misfiring cylinder; when T4<T, the fourth cylinder is a misfiring cylinder.

[0024] The limit T is a preset threshold value that is lower than the current average exhaust temperature. Taking a four-cylinder engine as an example, if the current average exhaust temperature is (T1+T2+T3+T4) / 4, then the limit T is T=(T1+T2+T3+T4) / 4-preset threshold. For example, if the average exhaust temperature is 400℃ and the preset threshold is 50℃, then the limit T can be set to 350℃.

[0025] In other words, the misfire condition can be defined as the current exhaust temperature of the misfired cylinder being lower than the current average exhaust temperature of all cylinders, and the difference between the current average exhaust temperature and the current exhaust temperature of the misfired cylinder being greater than a preset threshold. This condition can adaptively adjust the judgment criteria based on the current engine operating status, significantly improving the accuracy of misfire cylinder detection. Taking a four-cylinder engine as an example, the preset misfire condition is Tx < (T1 + T2 + T3 + T4) / 4, and (T1 + T2 + T3 + T4) / 4 - Tx > T 预 The cylinder whose exhaust temperature Tx meets the above conditions is the misfire cylinder, where x = 1, 2, 3, 4.

[0026] It should be noted that (T1+T2+T3+T4) / 4 is the value obtained at the same time as T1, T2, T3 and T4.

[0027] S103, if so, then the corresponding diagnostic process is determined based on the relationship between the flare temperature of the flare cylinder and the first preset value and the second preset value, wherein the first preset value is greater than the second preset value.

[0028] The first preset value can be 100℃, and the second preset value can be 0℃. It should be noted that when the cylinder is burning, even in a misfire state, the exhaust temperature is generally greater than 100℃ based on experience. If the exhaust temperature of a cylinder is less than or equal to 100℃, it indicates another fault. Therefore, when there is a misfire in the engine, different diagnostic procedures are set based on the misfire temperature of the misfired cylinder, that is, the different exhaust temperatures of a cylinder in a misfire state.

[0029] Specifically, there are three scenarios: First, when the ignition temperature of the ignition cylinder is greater than the first preset value of 100℃, the first diagnostic process is initiated; second, when the ignition temperature of the ignition cylinder is less than or equal to the first preset value of 100℃ and greater than the second preset value of 0℃, the second diagnostic process is initiated; third, when the ignition temperature of the ignition cylinder is less than or equal to the second preset value of 0℃, the third diagnostic process is initiated. Different diagnostic paths correspond to different fault causes, which can gradually narrow down the fault range and quickly locate the fault point.

[0030] S104, when the misfire temperature of the misfire cylinder is greater than the first preset value, the diagnostic process includes: controlling the engine to switch from alternative fuel mode to diesel mode, and determining whether the current exhaust temperature of the misfire cylinder still meets the preset misfire conditions.

[0031] In the alternative fuel mode, both the diesel injector and the alternative fuel injector operate simultaneously; that is, diesel fuel is used as the ignition fuel to ignite the alternative fuel for combustion. In the diesel mode, only the diesel injector operates. The amount of diesel fuel injected by the diesel injector differs depending on the engine's operating mode. In other words, the amount of diesel fuel injected in the alternative fuel mode is less than the amount injected in the diesel mode.

[0032] S105, if so, generate a prompt message to stop and check the diesel injector of the misfire cylinder; S106, if not, then control the engine based on the acquired execution command, wherein the execution command is a first execution command or a second execution command. Under the first execution command, control the engine to continue operating in diesel mode. Under the second execution command, continue to diagnose the engine.

[0033] In this embodiment, the engine initially operates in alternative fuel mode. If a misfire occurs in one cylinder, the engine is switched from alternative fuel mode to diesel mode to troubleshoot the problem. After the switch, the exhaust temperature of the misfired cylinder is collected and assessed again. If the exhaust temperature still meets the preset misfire conditions after the switch, it indicates that the exhaust temperature of the misfired cylinder has not recovered, and the misfire fault is most likely caused by an abnormal diesel supply. A diagnostic prompt for the corresponding diesel system fault can be output, such as generating a message to stop the engine and check the diesel injector of the misfired cylinder. If the exhaust temperature of the misfired cylinder no longer meets the preset misfire conditions after the switch, it indicates that the fault may originate from the alternative fuel side, requiring further investigation, or the engine can continue operating in diesel mode. This allows for emergency use in diesel mode in the event of an engine misfire, ensuring operational reliability, while also initially identifying the source of the fault, narrowing the scope of investigation, and improving the efficiency of diagnosis and repair.

[0034] In one embodiment, the operator decides whether to continue diagnostics or operate in diesel mode. That is, after the engine switches to diesel mode, if the exhaust temperature of the misfired cylinder returns to normal, i.e., the preset misfire condition is no longer met, an interactive prompt message can be generated to select an execution command, such as whether to execute the continue diagnostic command. If the operator selects no, a first execution command is generated; if the operator selects yes, a second execution command is generated.

[0035] Therefore, the dual-fuel engine misfire fault diagnosis method proposed in this invention does not immediately shut down the engine for manual troubleshooting upon the occurrence of a misfired cylinder. Instead, it determines the problem on the diesel supply side by switching to diesel mode. If the exhaust temperature of the misfired cylinder returns to normal after switching diesel mode, it indicates that there is no fault on the diesel supply side. Conversely, if the exhaust temperature does not return to normal after switching diesel mode, a fault on the diesel supply side is detected, and a message prompting to shut down and check the diesel injectors is output. This allows the engine to continue operating when there is no fault on the diesel supply side, ensuring operational reliability. When there is a fault on the diesel supply side, the scope of troubleshooting is narrowed, improving the efficiency of diagnosis and repair.

[0036] Optionally, the execution instruction is a second execution instruction, and controlling the engine based on the acquired execution instruction includes: Generate an interactive message to select whether to unload the engine based on the second execution instruction; Based on the acquired engine unloading command, the engine's target speed is controlled to reach the calibrated speed, and it is determined whether the engine's actual speed has reached the calibrated speed. If so, the engine is controlled to switch from diesel mode to alternative fuel mode. If not, a speed control fault prompt message is generated.

[0037] It should be noted that if the operator chooses to continue diagnostics on the misfired cylinder, i.e., when the second execution command controls the engine, an interactive message is generated to select whether to unload the engine. If the operator selects "yes," the engine is unloaded; if the operator selects "no," it means the operator does not wish to continue diagnostics, and the engine continues to run in diesel mode. This not only corrects the error where the operator intended to select the first execution command but mistakenly triggered the second execution command, but also provides a second confirmation for the operator when selecting the second execution command to continue diagnostics.

[0038] Understandably, the second execution command primarily targets issues related to the alternative fuel side. Therefore, when the operator chooses to continue diagnostics, the engine's diesel mode needs to be switched to alternative fuel mode. To avoid excessive fluctuations in output torque, which could affect operational stability and potentially trigger secondary faults such as surge or engine shutdown, the engine needs to be unloaded and its speed brought to the calibrated speed before switching to alternative fuel mode. This reduces operational fluctuations, ensures the smoothness of the diagnostic process, and prevents load interference from causing deviations in the diagnostic results. Therefore, to increase the operator's margin for error and ensure the smoothness of the diagnostic process, an interactive message is generated under the second execution command to select whether to unload the engine.

[0039] If the operator selects engine unloading, it is also necessary to determine if there is any abnormality in the engine speed control system. If the actual speed can successfully reach the calibrated speed, it indicates that there is no abnormality in the engine speed control system. At this time, the operator can switch back to the alternative fuel mode to further investigate the cause of the fault on the alternative fuel side. If the actual speed cannot reach the calibrated speed, it indicates that there is an abnormality in the engine speed control system. A corresponding prompt message will be generated directly to help maintenance personnel quickly locate the fault point.

[0040] Optionally, after controlling the engine to switch from diesel mode to alternative fuel mode, the following steps are also included: Determine whether the current exhaust temperature of the misfire cylinder still meets the preset misfire conditions. If yes, generate a prompt message for a faulty alternative fuel injector and a shutdown inspection for the misfire cylinder; otherwise, generate a prompt message for a shutdown inspection of the alternative fuel injector of the misfire cylinder.

[0041] In other words, after the engine switches to alternative fuel mode, if the current exhaust temperature of the misfired cylinder still meets the preset misfire conditions, and there is no problem with the diesel supply side, a prompt message for a faulty alternative fuel injector in the misfired cylinder and a shutdown inspection can be generated. If the current exhaust temperature of the misfired cylinder no longer meets the preset misfire conditions, i.e., the current exhaust temperature is no longer lower than the current average exhaust temperature, or the current exhaust temperature is lower than the current average exhaust temperature, but the difference between the current exhaust temperature and the current average exhaust temperature is less than a preset threshold, then it can be determined that the misfired cylinder is an intermittent misfire, and a prompt message for a shutdown inspection of the alternative fuel injector in the misfired cylinder can be generated.

[0042] In this way, the scope of troubleshooting for misfires can be gradually narrowed down without disassembling the engine, and the specific faulty component can be accurately located. Whether the fault is on the diesel supply side or the alternative fuel side, it can be gradually confirmed through mode switching and exhaust temperature detection. This not only saves the tedious process of manually checking each component one by one, but also ensures the engine continues to run after a fault occurs, avoiding production interruptions or safety risks caused by sudden shutdowns, thus balancing operational reliability and maintenance efficiency.

[0043] Optionally, after generating the selection interaction message on whether to unload the engine based on the second execution instruction, the method further includes: Based on the acquired engine non-unload command, the engine is controlled to continue running in diesel mode.

[0044] When the operator chooses not to unload the engine, it means that the operator does not intend to continue fault diagnosis for the time being, or the on-site working conditions do not support the immediate unloading of the engine for troubleshooting. In this case, maintaining the diesel mode will ensure the engine continues to work under load, avoiding the impact of unloading or switching modes on the normal progress of current production operations. Subsequent diagnosis and maintenance can be carried out when the working conditions allow, which further adapts to the actual operating needs of different sites.

[0045] Optionally, after controlling the engine to switch from alternative fuel mode to diesel mode, and the current exhaust temperature of the misfire cylinder does not meet the preset misfire condition, and before controlling the engine based on the acquired execution commands, the first diagnostic process further includes: Generate an interactive prompt message to select the execution mode instruction.

[0046] In this embodiment of the invention, messages can be output and displayed to the operator via voice broadcast and / or via a central control screen. When outputting via the central control screen, the screen can be equipped with clear interactive selection buttons for easy access and confirmation by the operator. When outputting via voice broadcast, the system can directly broadcast fault conditions and optional operation prompts, reminding the operator to make timely decisions and preventing them from missing key information, thus ensuring the timeliness and accuracy of information transmission.

[0047] Optionally, when the misfire temperature of the misfire cylinder is less than or equal to a first preset value and greater than a second preset value, the diagnostic process is as follows: the second diagnostic process includes controlling the engine to switch from alternative fuel mode to diesel mode and generating a prompt message to stop the engine and check the diesel injectors of the misfire cylinder.

[0048] Specifically, if the misfire temperature of the misfire cylinder is less than or equal to the first preset value, it indicates that the alternative fuel has not been ignited or is mostly unburned, clearly indicating a diesel injector malfunction. Furthermore, to prevent the alternative fuel from continuously being injected in an unburned state, the engine needs to be switched to diesel mode. Then, if the misfire temperature of the misfire cylinder is less than or equal to the first preset value of 100°C and greater than the second preset value of 0°C, the second diagnostic process is initiated. This involves switching to diesel mode first and then directly prompting the operator to prioritize checking the diesel injector of that cylinder, further narrowing down the troubleshooting scope and quickly identifying the possible faulty component.

[0049] Optionally, when the misfire temperature of the misfire cylinder is less than or equal to the second preset value, the diagnostic process is a third diagnostic process, which includes: controlling the engine to switch from alternative fuel mode to diesel mode, and generating a prompt message to stop the engine and check the exhaust temperature sensor of the misfire cylinder.

[0050] Specifically, when the misfire temperature of the misfire cylinder is less than or equal to a second preset value (i.e., less than or equal to the second preset value of 0°C), it indicates that the exhaust temperature sensor cannot detect the exhaust temperature that is essential for engine operation. This signifies a malfunction of the sensor. Since the exhaust temperature of each cylinder is related to the engine's alternative fuel injection control program, the engine cannot operate in alternative fuel mode without exhaust temperature, requiring a switch to diesel mode. Furthermore, when the misfire temperature of the misfire cylinder is less than or equal to the second preset value, the engine is switched from alternative fuel mode to diesel mode, and a message prompting the operator to stop and check the exhaust temperature sensor of the misfire cylinder is generated. This prompts the operator to prioritize checking the exhaust temperature sensor of that cylinder, further narrowing down the troubleshooting scope and quickly identifying the potentially faulty component.

[0051] Optionally, the preset misfire condition is that the current exhaust temperature of the misfire cylinder is less than the current average exhaust temperature of all cylinders, and the difference between the current average exhaust temperature and the current exhaust temperature of the misfire cylinder is greater than a preset threshold.

[0052] In one embodiment, the preset threshold can be set to a fixed value. If a cylinder in the engine misfires, the method further includes generating a warning message, which can be one or a combination of a buzzer, a voice alarm, or a flashing light.

[0053] Figure 2 This is a flowchart of another method for diagnosing misfires in a dual-fuel engine, as proposed in an embodiment of the present invention. Figure 2 As shown, the method includes: S201, Start, determine whether the current exhaust temperature of cylinder # meets the preset misfire condition. If yes, execute S202; otherwise, execute S203. S202, determine whether the misfire temperature of cylinder # is greater than 100℃. If yes, proceed to S204; otherwise, proceed to S205. S203, maintain alternative fuel mode, return to S201; S204, Exit alternative fuel mode, switch to diesel mode, execute S208; S205, determine whether the misfire temperature of cylinder # is greater than 0℃. If yes, proceed to S206; otherwise, proceed to S207. S206, Exit alternative fuel mode, switch to diesel mode, output "Stop engine to check # cylinder diesel injector" prompt, end; S207, Exit alternative fuel mode, switch to diesel mode, output "Please stop the engine and check the exhaust temperature sensor of cylinder #", then end; S208, determine whether the current exhaust temperature of cylinder # has returned to normal. If yes, proceed to S209; otherwise, proceed to S210. S209, output the "Execute automatic diagnostic program?" option. If the receiving operator selects yes, then execute S211; if the receiving operator selects no, then execute S212. S210 outputs the message "Please stop the engine and check the diesel injector of cylinder #", then ends; S211 generates the second execution instruction, and executes S213; S212, generate the first execution instruction, execute S214; S213, output "Please confirm whether the engine is unloaded" option. If the receiving operator selects yes, then execute S215. If the receiving operator selects no, then execute S216. S214, maintain diesel mode operation, end; S215, obtain engine unloading command, execute S217; S216, obtain the engine non-unload instruction, return to S214; S217, adjust the engine speed and determine whether the actual engine speed has reached the rated speed; if yes, execute S218; if no, execute S219. S218 controls the engine to switch from diesel mode to alternative fuel mode, and executes S220; S219, Speed ​​control fault, End; S220, determine whether the current exhaust temperature of cylinder # meets the preset misfire condition. If yes, execute S221; otherwise, execute S222. S221, output "#Cylinder alternative fuel injector malfunction, please stop the machine for inspection", end; S222, outputs the message "Intermittent engine misfire, please stop the engine and check the # cylinder alternative fuel injector", then ends.

[0054] Specifically, when the exhaust temperature of a certain cylinder is detected to be lower than the average exhaust temperature of all cylinders, and the difference between the average exhaust temperature and the exhaust temperature of that cylinder is greater than the set allowable value (i.e., the aforementioned preset threshold), the following process is initiated: Step 1: Determine the problem based on the exhaust temperature reading of the cylinder. If the exhaust temperature reading is 0 or negative, the diagnostic system will determine that the sensor is faulty and issue an alarm. At the same time, the engine will exit the alternative fuel mode and switch to diesel mode. The diagnostic system will output the message "Please stop the engine and check the exhaust temperature sensor of cylinder #". If the exhaust temperature reading is between 0 and 100°C, it is determined to be a diesel injector malfunction. An alarm will be triggered, the alternative fuel mode will be exited, the diesel mode will be switched back, and the message "Please stop the engine and check the diesel injector of cylinder #" will be displayed. If the exhaust temperature reading is greater than 100℃, an alarm will be triggered, the alternative fuel mode will be exited, the diesel mode will be switched, and subsequent steps will be performed.

[0055] Step 2: After switching to diesel mode, determine whether the difference between the average exhaust temperature and the exhaust temperature of the cylinder with the original low exhaust temperature has returned to the set allowable range.

[0056] If the exhaust temperature does not recover, the message "Please stop the engine and check the diesel injectors" will be displayed, and the program will terminate. If the exhaust temperature recovers, the option "Execute automatic diagnostic program?" will be displayed.

[0057] Step 3: If the operator selects the "Do not execute" option, the diesel operation mode will be maintained, and switching to alternative fuel mode will not be allowed. The program will terminate. If the operator selects the "Execute" option, the message "Please confirm whether the engine is unloaded" will be displayed. If the operator selects the "Do not unload" option, the diesel operation mode will be maintained, and switching to alternative fuel mode will not be allowed, and the program will terminate. If the operator selects the "Unload" option, the engine will be unloaded. If the engine speed during unloading is not the rated speed, the engine speed will be automatically increased to the rated speed. If the engine speed during unloading is the rated speed, the rated speed will be maintained.

[0058] Step 4: The engine speed is checked by the speed sensor to see if the engine speed has reached the calibrated speed. If the command is not executed, "speed control fault" is output and the program terminates. If the engine speed is detected to have reached the rated speed, the engine operating mode will be switched to alternative fuel mode.

[0059] Step 5: Use the exhaust temperature sensor to detect whether the exhaust temperature of the misfired cylinder is lower than the average exhaust temperature, and whether the difference between the average exhaust temperature and the cylinder's exhaust temperature is greater than the allowable value. If the exhaust temperature of the misfired cylinder is lower than the average exhaust temperature, but the difference between the average exhaust temperature and the cylinder's exhaust temperature is within the allowable range, or if the exhaust temperature of the misfired cylinder is not lower than the average exhaust temperature, then it is determined as "No," and the message "Intermittent engine misfire fault, please stop the engine and check the # cylinder alternative fuel injection valve" is output, and the diagnostic program terminates; If the exhaust temperature of the original misfired cylinder is lower than the average exhaust temperature, and the difference between the average exhaust temperature and the cylinder's exhaust temperature is greater than the allowable value, the system will output the message "#Cylinder alternative fuel injector malfunction, please stop the machine for inspection" and the program will terminate.

[0060] This solution uses a simple, automated diagnostic method to accurately determine the cause of misfires in dual-fuel engines; it does not rely on manual troubleshooting, thus improving fault diagnosis efficiency and saving time and costs.

[0061] Figure 3 This is a block diagram of the dual-fuel engine misfire fault diagnosis device proposed in an embodiment of the present invention. Figure 3As shown, the device includes: multiple exhaust temperature sensors 10, a controller 20, and an interaction module 30. Each exhaust temperature sensor 10 is used to detect the exhaust temperature of each cylinder. The interaction module 30 is used to output messages generated by the controller and also to respond to user input operations. The controller 20 is used to execute the dual-fuel engine misfire fault diagnosis method proposed in any embodiment of the present invention.

[0062] The exhaust temperature sensors 10, located within the exhaust manifolds of each cylinder, are high-temperature resistant sensing elements capable of accurately collecting exhaust temperature data from each cylinder in real time. These sensors transmit the collected temperature signals to the controller 20, ensuring the accuracy and reliability of the temperature data relied upon for fault diagnosis and improving diagnostic accuracy from the data source. The interaction module 30 integrates a voice broadcast unit and / or a display unit. It can select an appropriate information output method based on the operator's usage habits or the characteristics of the on-site working conditions. It also supports multiple input methods such as touch and physical buttons, facilitating quick feedback of operating commands and enabling a human-machine collaborative fault diagnosis process. The controller 20, as the core control and computing unit of the entire device, can directly interface with the existing control system of the dual-fuel engine without requiring large-scale modifications to the existing engine's control architecture. This results in low modification costs, strong adaptability, and direct application in the upgrade and modification of existing dual-fuel engines. It can also be pre-installed in newly manufactured dual-fuel engine equipment.

[0063] The controller includes: an acquisition module for acquiring the exhaust temperature of each cylinder in real time; The misfire detection module is used to determine whether any cylinder is a misfire cylinder based on the current exhaust temperature of any cylinder and the preset misfire conditions. If so, the corresponding diagnostic process is determined based on the relationship between the misfire temperature of the misfire cylinder and the first preset value and the second preset value. The first preset value is greater than the second preset value. The first diagnostic process module is used to control the engine to switch from alternative fuel mode to diesel mode when the misfire temperature of the misfire cylinder is greater than a first preset value, and to determine whether the current exhaust temperature of the misfire cylinder still meets the preset misfire conditions. If yes, a prompt message is generated to stop the engine and check the diesel injector of the misfire cylinder. If no, the engine is controlled based on the obtained execution command, wherein the execution command is a first execution command or a second execution command. Under the first execution command, the engine is controlled to continue to run in diesel mode. Under the second execution command, the engine diagnosis continues.

[0064] The first diagnostic process module includes a first execution unit and a second execution unit. The second execution unit includes: The message generation subunit is used to generate an interactive message for selecting whether to unload the engine based on the second execution instruction. The alternative fuel mode switching subunit is used to control the engine to reach the target speed based on the acquired engine unloading command, and to determine whether the actual speed of the engine has reached the calibrated speed. If so, the engine is controlled to switch from diesel mode to alternative fuel mode. If not, a speed control fault prompt message is generated.

[0065] The second execution unit further includes: The alternative fuel injector inspection subunit is used to determine whether the current exhaust temperature of the misfire cylinder still meets the preset misfire conditions. If yes, it generates a prompt message for alternative fuel injector failure of the misfire cylinder and shutdown inspection; if no, it generates a prompt message for shutdown inspection of the alternative fuel injector of the misfire cylinder.

[0066] The second execution unit further includes: The diesel mode maintenance subunit is used to control the engine to continue operating in diesel mode based on the acquired engine non-unload command.

[0067] The first diagnostic process module also includes: The message generation unit is used to generate interactive prompt messages for selecting the execution mode instruction.

[0068] The controller also includes a second diagnostic process module, which controls the engine to switch from alternative fuel mode to diesel mode when the misfire temperature of the misfire cylinder is less than or equal to a first preset value and greater than a second preset value, and generates a prompt message to stop the engine and check the diesel injectors of the misfire cylinder.

[0069] The controller also includes a third diagnostic process module, which controls the engine to switch from alternative fuel mode to diesel mode when the misfire temperature of the misfire cylinder is less than or equal to a second preset value, and generates a prompt message to stop the engine and check the exhaust temperature sensor of the misfire cylinder.

[0070] Optionally, the preset misfire condition is that the current exhaust temperature of the misfire cylinder is less than the current average exhaust temperature of all cylinders, and the difference between the current average exhaust temperature and the current exhaust temperature of the misfire cylinder is greater than a preset threshold.

[0071] This device has the same beneficial effects as the aforementioned method embodiments, and will not be repeated here.

[0072] This invention also proposes a dual-fuel engine, including the dual-fuel engine misfire fault diagnosis device as proposed in this invention.

[0073] This invention also proposes a readable storage medium storing computer-executable instructions. When these computer-executable instructions are executed by a processor, they implement the dual-fuel engine misfire fault diagnosis method described in any of the above embodiments. By using the storage medium, the misfire fault diagnosis solution can be quickly ported and deployed to different dual-fuel engine control devices. The solution is easy to port and deploy, flexible in adaptation, and can meet the fault diagnosis function upgrade needs in different scenarios.

[0074] In actual operation, when a dual-fuel engine operates in alternative fuel mode, if a misfire occurs in one cylinder, the corresponding exhaust temperature will deviate significantly. This invention, by collecting the real-time exhaust temperature of each cylinder and combining graded temperature thresholds with step-by-step diagnostic and troubleshooting logic, can quickly locate the fault point. It can not only distinguish whether the fault is due to a diesel injector fault, an alternative fuel injector fault, or a detection fault in the exhaust temperature sensor itself, but also provide corresponding transitional handling solutions based on the severity of the fault. Under the premise of ensuring operational safety, it can minimize unnecessary downtime, improve fault handling efficiency, reduce the production impact caused by the fault, and significantly reduce the difficulty for operators to troubleshoot, providing technical support for the stable and reliable operation of dual-fuel engines.

[0075] In summary, the dual-fuel engine and its misfire fault diagnosis method and apparatus proposed in this embodiment of the invention include: acquiring the exhaust temperature of each cylinder in real time; determining whether any cylinder is a misfire cylinder based on the current exhaust temperature of any cylinder and a preset misfire condition; if so, determining a corresponding diagnostic process based on the relationship between the misfire temperature of the misfire cylinder and a first preset value and a second preset value, wherein the first preset value is greater than the second preset value; when the misfire temperature of the misfire cylinder is greater than the first preset value, the diagnostic process is as follows: the first diagnostic process includes: controlling the engine to switch from alternative fuel mode to diesel mode, and determining whether the current exhaust temperature of the misfire cylinder still meets the preset misfire condition; if so, generating a prompt message to stop and check the diesel injector of the misfire cylinder; if not, controlling the engine based on the acquired execution command, wherein the execution command is a first execution command or a second execution command; under the first execution command, controlling the engine to continue running in diesel mode; under the second execution command, continuing to diagnose the engine. Therefore, this invention does not rely on manual troubleshooting and can automatically diagnose misfire faults in dual-fuel engines, accurately determine the cause of misfire faults in dual-fuel engines, improve fault diagnosis efficiency, and save time and costs.

[0076] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A misfire fault diagnostic method for a dual-fuel engine, characterized by, include: Real-time acquisition of exhaust temperature for each cylinder; Based on the current exhaust temperature of any cylinder and the preset misfire conditions, determine whether any cylinder is a misfire cylinder. If so, determine the corresponding diagnostic process based on the relationship between the misfire temperature of the misfire cylinder and the first preset value and the second preset value, wherein the first preset value is greater than the second preset value. When the misfire temperature of the misfire cylinder is greater than the first preset value, the diagnostic process is as follows: the first diagnostic process includes controlling the engine to switch from alternative fuel mode to diesel mode, and determining whether the current exhaust temperature of the misfire cylinder still meets the preset misfire condition. If yes, a prompt message is generated to stop and check the diesel injector of the misfire cylinder. If no, the engine is controlled based on the obtained execution command, wherein the execution command is a first execution command or a second execution command. Under the first execution command, the engine is controlled to continue running in the diesel mode. Under the second execution command, the engine is continued to be diagnosed.

2. The misfire fault diagnostic method for a dual-fuel engine according to claim 1, characterized by, The execution instruction is the second execution instruction, and the control of the engine based on the acquired execution instruction includes: Generate an interactive message on whether to unload the engine based on the second execution instruction; Based on the acquired engine unloading command, the engine's target speed is controlled to reach the calibrated speed, and it is determined whether the engine's actual speed has reached the calibrated speed. If so, the engine is controlled to switch from the diesel mode to the alternative fuel mode. If not, a speed control fault prompt message is generated.

3. The method for diagnosing misfires in a dual-fuel engine according to claim 2, characterized in that, After controlling the engine to switch from diesel mode to alternative fuel mode, the method further includes: Determine whether the current exhaust temperature of the misfire cylinder still meets the preset misfire condition. If yes, generate a prompt message for a faulty alternative fuel injector and a shutdown inspection of the misfire cylinder; otherwise, generate a prompt message for a shutdown inspection of the alternative fuel injector of the misfire cylinder.

4. The method for diagnosing misfires in a dual-fuel engine according to claim 2, characterized in that, After generating the selection interaction message regarding whether to unload the engine based on the second execution instruction, the process further includes: Based on the acquired engine non-unload command, the engine is controlled to continue operating in the diesel mode.

5. The method for diagnosing misfires in a dual-fuel engine according to claim 1, characterized in that, After the engine is switched from alternative fuel mode to diesel mode and the current exhaust temperature of the misfired cylinder does not meet the preset misfire condition, and before the engine is controlled based on the acquired execution command, the first diagnostic process further includes: Generate an interactive prompt message to select the instruction to be executed.

6. The method for diagnosing misfires in a dual-fuel engine according to claim 1, characterized in that, When the misfire temperature of the misfire cylinder is less than or equal to the first preset value and greater than the second preset value, the diagnostic process is a second diagnostic process including: controlling the engine to switch from the alternative fuel mode to the diesel mode, and generating a prompt message to stop the engine and check the diesel injector of the misfire cylinder.

7. The method for diagnosing misfires in a dual-fuel engine according to claim 1, characterized in that, When the misfire temperature of the misfire cylinder is less than or equal to the second preset value, the diagnostic process is a third diagnostic process, which includes: controlling the engine to switch from the alternative fuel mode to the diesel mode, and generating a prompt message to stop the engine and check the exhaust temperature sensor of the misfire cylinder.

8. The method for diagnosing misfires in a dual-fuel engine according to any one of claims 1-7, characterized in that, The preset misfire condition is that the current exhaust temperature of the misfire cylinder is less than the current average exhaust temperature of all cylinders, and the difference between the current average exhaust temperature and the current exhaust temperature of the misfire cylinder is greater than a preset threshold.

9. A dual-fuel engine misfire fault diagnosis device, characterized in that, include: The system includes multiple exhaust temperature sensors, a controller, and an interaction module. Each exhaust temperature sensor is used to detect the exhaust temperature of each cylinder. The interaction module is used to output messages generated by the controller and to respond to user input operations. The controller is used to execute the dual-fuel engine misfire fault diagnosis method as described in any one of claims 1-8.

10. A dual-fuel engine, characterized in that, Includes the dual-fuel engine misfire fault diagnosis device as described in claim 9.

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