Method and system for diagnosing fuel ignition fault of hot surface auxiliary compression ignition methanol engine

Abstract

The invention relates to a fuel ignition fault diagnosis method and system for a hot surface auxiliary compression ignition methanol engine. The method comprises the following steps: in response to loss of a temperature signal of a glow plug, normal current signal of the glow plug and normal exhaust temperature signal of an engine, diagnosing that a temperature feedback circuit of the glow plug is abnormal; in response to existence of a glow plug temperature signal, a glow plug current signal abnormality and an engine exhaust temperature signal abnormality, diagnosing that a heating function of the glow plug is abnormal or a heating circuit is overloaded; if the temperature signal of the glow plug is lost, the current signal of the glow plug is normal and the exhaust temperature signal of the engine is abnormal, the ceramic body at the head of the glow plug is diagnosed to be partially damaged but not broken; and in response to loss of the temperature signal of the glow plug, abnormality of the current signal of the glow plug and abnormality of the exhaust temperature signal of the engine, diagnosing that the ceramic body of the head of the glow plug is broken. According to the invention, the fault of the glow plug can be accurately diagnosed.

Description

Technical Field

[0001] The present invention relates to the technical field of internal combustion engine engineering, in particular to a method and system for diagnosing fuel ignition faults of a hot surface assisted compression ignition methanol engine. Background Art

[0002] An internal combustion engine is a power device that converts internal energy into mechanical energy and is widely used in fields such as automobiles, ships, and airplanes. With the increasingly strict environmental protection requirements, internal combustion engines fueled by traditional gasoline, diesel, etc. are facing increasing emission pressures. Methanol, as a clean fuel, has the advantages of high combustion efficiency and low emissions. Therefore, the research and application of methanol internal combustion engines have received more and more attention. The field of thermal energy engineering is to study how to efficiently utilize thermal energy, including technologies such as thermal energy conversion, thermal energy storage, and thermal energy utilization. In a methanol internal combustion engine, the fuel heating and ignition system is a key component, and its main function is to ignite methanol fuel by heating it to its self-ignition temperature, thereby achieving compression ignition combustion. The field of control engineering is to study how to achieve automatic control and regulation of various devices through a control system. In a methanol internal combustion engine, the control of the fuel ignition system is crucial to ensure the full combustion of fuel and the normal operation of the engine.

[0003] Existing methanol internal combustion engine fuel heating and ignition systems usually use glow plugs as heating elements to heat methanol fuel with the heat generated by the glow plugs. At the same time, a controller is used to monitor and control the heating temperature. However, such a system has some problems. For example, glow plugs are prone to damage, the temperature control accuracy is not high, and if the glow plug undergoes structural damage (breakage), there is a risk of cylinder scoring. Therefore, accurately diagnosing the state of the glow plug is of utmost importance for its practical application in the engine.

[0004] However, existing methanol internal combustion engine fuel heating and ignition systems have some problems in practical applications. First of all, as a heating element, the service life of the glow plug is short and it is prone to failure due to high-temperature burnout or mechanical damage. Secondly, existing systems cannot accurately diagnose glow plug faults and can only ensure the normal operation of the system by regular maintenance and replacement of glow plugs, which not only increases the maintenance cost but also affects the reliability of the engine. Therefore, existing methanol internal combustion engine fuel heating and ignition systems have obvious deficiencies in terms of safety and economy. Summary of the Invention

[0005] For this reason, the technical problem to be solved by the present invention is to overcome the problem that existing technologies cannot accurately diagnose glow plug faults.

[0006] To solve the above technical problem, the present invention provides a method for diagnosing fuel ignition faults of a hot surface assisted compression ignition methanol engine, including: During the operation of a methanol engine, temperature signals of glow plugs, current signals of glow plugs, and exhaust gas temperature signals of the engine are collected in real time; among them, the temperature signals of the glow plugs are collected by the ceramic body at the head of the glow plugs. If the temperature signal of the glow plug exists, the current signal of the glow plug is normal, and the exhaust gas temperature signal of the engine is normal, it is diagnosed that the methanol engine is operating normally; among them, if the deviation between the processed current signal of the glow plug and the current calibration base map exceeds a preset current threshold, it is determined as abnormal, otherwise it is normal; if the deviation between the processed exhaust gas temperature signal of the engine and the exhaust gas temperature calibration base map exceeds a preset temperature threshold, it is determined as abnormal, otherwise it is normal. If the temperature signal of the glow plug exists, the current signal of the glow plug is abnormal, and the exhaust gas temperature signal of the engine is normal, if the current signal of the glow plug is abnormally low, it is diagnosed that the heating function of the glow plug is abnormal, and if the current signal of the glow plug is abnormally high, it is diagnosed that the heating circuit of the glow plug is overloaded. If the temperature signal of the glow plug is lost, the current signal of the glow plug is normal, and the exhaust gas temperature signal of the engine is normal, it is diagnosed that the temperature feedback circuit of the glow plug is abnormal. If the temperature signal of the glow plug exists, the current signal of the glow plug is abnormal, and the exhaust gas temperature signal of the engine is abnormal, if the exhaust gas temperature signal of the engine is abnormally low, it is diagnosed that the heating function of the glow plug is abnormal, and if the exhaust gas temperature signal of the engine is abnormally high, it is diagnosed that the heating circuit of the glow plug is overloaded. If the temperature signal of the glow plug is lost, the current signal of the glow plug is normal, and the exhaust gas temperature signal of the engine is abnormal, it is diagnosed that the ceramic body at the head of the glow plug is partially damaged but not broken. If the temperature signal of the glow plug is lost, the current signal of the glow plug is abnormal, and the exhaust gas temperature signal of the engine is abnormal, it is diagnosed that the ceramic body at the head of the glow plug is broken.

[0007] In an embodiment of the present invention, if the temperature signal of the glow plug exists, the current signal of the glow plug is abnormal, and the exhaust gas temperature signal of the engine is normal, or, if the temperature signal of the glow plug is lost, the current signal of the glow plug is normal, and the exhaust gas temperature signal of the engine is normal, an alarm is triggered.

[0008] In an embodiment of the present invention, it further includes: a spare glow plug is installed in the methanol engine, and the spare glow plug does not work during the normal operation of the engine. If the temperature signal of the glow plug exists, the current signal of the glow plug is abnormal, and the exhaust gas temperature signal of the engine is abnormal, switch to the spare glow plug and trigger an alarm.

[0009] In an embodiment of the present invention, in response to the loss of the glow plug temperature signal, the normal glow plug current signal, and the abnormal engine exhaust temperature signal, an emergency stop is triggered.

[0010] In an embodiment of the present invention, in response to the loss of the glow plug temperature signal, the abnormal glow plug current signal, and the abnormal engine exhaust temperature signal, an emergency stop is triggered.

[0011] In an embodiment of the present invention, the glow plug and the fuel injector sleeve are of an integrated structure, including: The fuel injector sleeve includes a receiving cavity for arranging the fuel injector and an end wall on one side of the receiving cavity. A central hole is penetrated through the end wall, and at least one through hole is distributed around the central hole on the end wall; The mounting sleeve is installed in the receiving cavity, and the mounting sleeve includes receiving holes corresponding to the through holes; The heating element includes a mounting end and a heating end. The mounting end extends into and is connected to the receiving hole, and the heating end extends out of the through hole; An adiabatic coating is provided at a position where the outer surface of the mounting sleeve contacts the fuel injector.

[0012] In an embodiment of the present invention, one mounting sleeve is provided, including a mounting sleeve hole corresponding to the position of the central hole, and the receiving holes are distributed around the mounting sleeve hole; alternatively, a plurality of mounting sleeves are provided, and each of the plurality of mounting sleeve holes is provided with a receiving hole corresponding to the through hole.

[0013] The present invention also provides a fault diagnosis system for fuel ignition of a hot surface assisted compression ignition methanol engine, including: A signal acquisition module for real-time acquisition of the glow plug temperature signal, the glow plug current signal, and the engine exhaust temperature signal during the operation of the methanol engine; wherein, the glow plug temperature signal is acquired by the ceramic body at the head of the glow plug; A fault diagnosis module for: In response to the existence of the glow plug temperature signal, the normal glow plug current signal, and the normal engine exhaust temperature signal, it is diagnosed that the methanol engine is operating normally; wherein, if the deviation between the processed glow plug current signal and the current calibration base map exceeds a preset current threshold, it is determined to be abnormal, otherwise it is normal; if the deviation between the processed engine exhaust temperature signal and the exhaust temperature calibration base map exceeds a preset temperature threshold, it is determined to be abnormal, otherwise it is normal; In response to the presence of the glow plug temperature signal, the abnormality of the glow plug current signal, and the normality of the engine exhaust temperature signal, if the glow plug current signal is abnormal and low, it is diagnosed that the heating function of the glow plug is abnormal; if the glow plug current signal is abnormal and high, it is diagnosed that the heating circuit of the glow plug is overloaded. In response to the loss of the glow plug temperature signal, the normality of the glow plug current signal, and the normality of the engine exhaust temperature signal, it is diagnosed that the temperature feedback circuit of the glow plug is abnormal. In response to the presence of the glow plug temperature signal, the abnormality of the glow plug current signal, and the abnormality of the engine exhaust temperature signal, if the engine exhaust temperature signal is abnormal and low, it is diagnosed that the heating function of the glow plug is abnormal; if the engine exhaust temperature signal is abnormal and high, it is diagnosed that the heating circuit of the glow plug is overloaded. In response to the loss of the glow plug temperature signal, the normality of the glow plug current signal, and the abnormality of the engine exhaust temperature signal, it is diagnosed that the ceramic body of the glow plug head is partially damaged but not broken. In response to the loss of the glow plug temperature signal, the abnormality of the glow plug current signal, and the abnormality of the engine exhaust temperature signal, it is diagnosed that the ceramic body of the glow plug head is broken.

[0014] The above technical solution of the present invention has the following advantages compared with the prior art: For the method and system for diagnosing fuel ignition faults of a hot surface assisted compression ignition methanol engine according to the present invention, when a glow plug fails, it can accurately diagnose faults such as breakage and damage of the glow plug ceramic body through the synchronous feedback of the current signal and the temperature signal, and can give an alarm or emergency stop in time, improving the safety of the methanol engine operation and solving the problem that the existing fuel heating ignition device of the methanol engine cannot adjust the heating temperature in real time according to the combustion situation.

[0015] The present invention integrally designs the glow plug and the injector sleeve, reducing the overall volume and occupying less space during use and layout, which is beneficial to the compact design of the internal combustion engine. At the same time, since the glow plug is integrated on the injector sleeve, the heating effect of the glow plug on the injector nozzle is reduced, improving the fuel utilization efficiency. In addition, this structure realizes the separation of the preheating mechanism and the engine body, which is beneficial to further simplifying the structure and reducing costs. Description of the Drawings

[0016] In order to make the content of the present invention easier to be clearly understood, the present invention will be further described in detail below according to the specific embodiments of the present invention and in conjunction with the drawings.

[0017] Figure 1 It is a flowchart of the method for diagnosing fuel ignition faults of a hot surface assisted compression ignition methanol engine according to the present invention.

[0018] Figure 2 This is a schematic diagram of the integrated structure of the glow plug and the fuel injector sleeve of the present invention.

[0019] Description of the reference numerals in the drawings of the specification: 1. Fuel injector sleeve; 11. Accommodating cavity; 12. End wall; 13. Central hole; 14. Through hole; 2. Mounting sleeve; 21. Accommodating hole; 22. Mounting sleeve hole; 3. Heating element; 31. Mounting end; 32. Heating end. Specific embodiments

[0020] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the embodiments given are not intended to limit the present invention.

[0021] In the present invention, when directions (up, down, left, right, front, and back) are described, it is only for the convenience of describing the technical solution of the present invention, rather than indicating or implying that the technical features referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0022] In the present invention, the meaning of "several" is one or more, the meaning of "multiple" is two or more, and "greater than", "less than", "exceeding", etc. are understood not to include the present number; "above", "below", "within", etc. are understood to include the present number. In the description of the present invention, if "first" and "second" are described, they are only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the technical features indicated or the sequence relationship of the technical features indicated.

[0023] In the present invention, unless otherwise clearly defined, words such as "set", "installed", "connected", etc. should be understood in a broad sense. For example, they can be directly connected, or indirectly connected through an intermediate medium; they can be fixedly connected, or detachably connected, or integrally formed; they can be mechanically connected, or electrically connected or capable of communicating with each other; they can be the communication inside two components or the interaction relationship between two components. Those skilled in the art can reasonably determine the specific meaning of the above words in the present invention in combination with the specific content of the technical solution.

[0024] Embodiment 1 Referring to Figure 1 As shown, this embodiment provides a method for diagnosing fuel ignition faults in a hot surface assisted compression ignition methanol engine, including: S1. During the operation of the methanol engine, the glow plug temperature signal, the glow plug current signal, and the engine exhaust temperature signal are collected in real time; among them, the glow plug temperature signal is collected by the ceramic body at the head of the glow plug.

[0025] It should be noted that the glow plug can achieve temperature monitoring by itself without adding a sensor. There are such products on the market currently. When the glow plug is not heated, it can still act as a temperature sensor to feedback temperature signals. The main high-temperature area and temperature measurement area of such glow plugs are both concentrated in the head. Therefore, the loss of its temperature signal is regarded as the fracture of the ceramic body at the head of the glow plug or the failure of the temperature signal circuit.

[0026] S2. In response to the existence of the glow plug temperature signal, the normal glow plug current signal, and the normal engine exhaust temperature signal, it is diagnosed that the methanol engine is operating normally; the glow plug is also in a normal working state, and the system has no faults; no alarm or operation is required.

[0027] It should be noted that if the deviation (such as 10%) between the glow plug current signal after processing (analog-to-digital conversion, filtering, etc.) and the current calibration base map exceeds the preset current threshold, it is determined as abnormal, otherwise it is normal; if the deviation (such as 10%) between the engine exhaust temperature signal after processing (analog-to-digital conversion, filtering, etc.) and the exhaust temperature calibration base map exceeds the preset temperature threshold, it is determined as abnormal, otherwise it is normal.

[0028] It can be understood that the current calibration base map and the exhaust temperature calibration base map are obtained by monitoring the methanol engine under predetermined working conditions (engine speed, fuel injection volume).

[0029] S3. In response to the existence of the glow plug temperature signal, the abnormal glow plug current signal, and the normal engine exhaust temperature signal, if the glow plug current signal is abnormal and low, it is diagnosed that the heating function of the glow plug is abnormal; if the glow plug current signal is abnormal and high, it is diagnosed that the heating circuit of the glow plug is overloaded.

[0030] It can be understood that if the glow plug temperature signal exists, it means that the ceramic body at the head of the glow plug is not fractured and can still feedback temperature. However, if the glow plug current signal is abnormally low, it means that the heating function of the glow plug is abnormal, but the engine exhaust temperature signal is normal and the methanol engine is running normally. This situation has a relatively low probability of occurrence; if the glow plug current signal is abnormally high, it means that the heating circuit is overloaded, and the cause of the overload needs to be judged manually. Therefore, after the alarm is triggered, it is processed and analyzed by the operator.

[0031] S4. In response to the loss of the glow plug temperature signal, the normal glow plug current signal, and the normal engine exhaust temperature signal, it is diagnosed that the temperature feedback circuit of the glow plug is abnormal.

[0032] It is understandable that if the glow plug current signal is normal and the engine exhaust temperature signal is normal, it indicates that the ceramic body of the glow plug can still be heated normally and the methanol engine is still running normally. However, if the glow plug temperature signal is lost, it is a circuit breakage fault in the temperature feedback circuit. Therefore, after the alarm is triggered, it is handled and analyzed by the operator.

[0033] S5. In response to the presence of the glow plug temperature signal, the abnormality of the glow plug current signal, and the abnormality of the engine exhaust temperature signal, if the engine exhaust temperature signal is abnormally low, it is diagnosed that the heating function of the glow plug is abnormal; if the engine exhaust temperature signal is abnormally high, it is diagnosed that the heating circuit of the glow plug is overloaded.

[0034] In addition, a spare glow plug is installed in the methanol engine, and the spare glow plug does not work when the engine is running normally.

[0035] It should be noted that the abnormality of the engine exhaust temperature signal indicates that the methanol engine cannot run normally at this time. If the engine exhaust temperature signal is abnormally low, it indicates that the heating function of the glow plug is damaged; if the engine exhaust temperature signal is abnormally high, it indicates that the heating circuit of the glow plug is overloaded, resulting in abnormal combustion in the cylinder. In either case, it can be diagnosed that the glow plug cannot work normally, but there is no physical structure damage. At this time, it should be immediately switched to the spare glow plug and an alarm should be triggered.

[0036] S6. In response to the loss of the glow plug temperature signal, the normal glow plug current signal, and the abnormality of the engine exhaust temperature signal, it is diagnosed that the ceramic body at the head of the glow plug is partially damaged but not broken.

[0037] It should be noted that the abnormality of the engine exhaust temperature signal indicates that the methanol engine cannot run normally at this time. The glow plug temperature signal is lost while the glow plug current signal is normal. At this time, since the ceramic body at the head of the glow plug is partially damaged but the main body exists (not broken), there is a risk of cylinder scoring and it is necessary to stop the engine urgently for inspection.

[0038] S7. In response to the loss of the glow plug temperature signal, the abnormality of the glow plug current signal, and the abnormality of the engine exhaust temperature signal, it is diagnosed that the ceramic body at the head of the glow plug is broken.

[0039] It should be noted that when the three faults of the loss of the glow plug temperature signal, the abnormality of the glow plug current signal, and the abnormality of the engine exhaust temperature signal exist simultaneously, it is very likely that the ceramic body at the head of the glow plug is completely broken in the cylinder at this time, the risk of cylinder scoring is extremely high, and the broken ceramic is likely to enter the exhaust and damage the turbine blades. Therefore, it is necessary to stop the engine urgently for inspection.

[0040] Refer to Figure 2 As shown, in some preferred solutions, the glow plug and the injector sleeve are of an integrated structure, including: The fuel injector sleeve 1 includes a receiving cavity 11 for arranging a fuel injector and an end wall 12 on one side of the receiving cavity 11. A central hole 13 is penetrated through the end wall 12, and at least one through hole 14 is distributed around the central hole 13 on the end wall 12. The mounting sleeve 2 is installed in the receiving cavity 11. The mounting sleeve 2 includes a receiving hole 21 corresponding to the through hole 14. The heating element 3 includes a mounting end 31 and a heating end 32. The mounting end 31 extends into and is connected to the receiving hole 21, and the heating end 32 extends out of the through hole 14.

[0041] An adiabatic coating is provided at the position where the outer surface of the mounting sleeve 2 contacts the fuel injector. The adiabatic coating includes a ceramic coating or an alumina coating. The thickness range of the adiabatic coating is 50 - 200 microns.

[0042] Through the above settings, the glow plug and the fuel injector sleeve 1 are integrally designed, reducing the overall volume and occupying less space during actual installation and layout, which is beneficial to the compact design of the internal combustion engine. At the same time, since the glow plug is integrated on the fuel injector sleeve 1, the heating influence of the glow plug on the fuel injector nozzle is reduced, and the fuel utilization efficiency is improved. Moreover, the glow plug is far from the fuel injector nozzle, avoiding the influence on fuel injection and improving the combustion efficiency. In addition, this structure realizes the separation of the preheating structure and the engine body, which is beneficial to further simplifying the structure and reducing costs. At the position where the mounting sleeve 2 contacts the fuel injector (nozzle), an adiabatic coating is applied to reduce the increase in the thermal load of the fuel injector nozzle caused by the heating of the glow plug. At the same time, since there is cooling water around the fuel injector nozzle and the glow plug, the influence of the glow plug heating on the fuel injector nozzle can be further offset. Through the action of the adiabatic coating and the cooling water, the influence of the glow plug heating on the fuel injector nozzle is reduced, improving the durability, reliability and service life of the fuel injector, which is beneficial to improving the working performance of the internal combustion engine.

[0043] Specifically, a plurality of through holes 14 are provided, and the plurality of through holes 14 are evenly distributed along the axis of the central hole 13. One heating element 3 is correspondingly arranged in each through hole 14.

[0044] One mounting sleeve 2 is provided, including a mounting sleeve hole 22 corresponding to the position of the central hole 13, and the receiving holes 21 are distributed around the mounting sleeve hole 22. In addition, a plurality of mounting sleeves 2 can also be provided, and the plurality of mounting sleeves 2 are distributed circumferentially along the receiving cavity 11, and the receiving holes 21 corresponding to the through holes 14 are respectively provided on the plurality of mounting sleeves 2.

[0045] The heating element 3 is a rod-shaped ceramic body with a heating resistor body disposed inside. Alternatively, the heating element 3 is a U-shaped ceramic body with a heating resistor body disposed inside, and both ends of the U-shaped ceramic body are respectively connected to a mounting sleeve 2.

[0046] Both between the mounting sleeve 2 and the fuel injector sleeve 1 and between the heating element 3 and the mounting sleeve 2 are connected by welding, and the mounting sleeve 2 is in contact with the inner end of the end wall 12 and / or the inner side wall of the accommodating cavity 11 (by welding).

[0047] The material of the mounting sleeve 2 includes copper, and the outer diameter of the copper sleeve is 15 - 25 mm; the material of the fuel injector sleeve 1 includes stainless steel, and the outer diameter is 20 - 30 mm; the length of the heating element 3 is 30 - 50 mm, and the outer diameter is 5 - 10 mm; the heating resistor body is made of a conductive ceramic material, and the resistivity is 0.1 - 1 ohm·meter. Specifically, the soldering joint between the ceramic body and the copper sleeve is welded by lead soldering.

[0048] This structure welds the ceramic body to the copper sleeve by lead soldering, and welds the copper sleeve into a plurality of small holes provided on the periphery of the fuel injector sleeve 1, so that the ceramic heating end 32 extends out of the fuel injector sleeve 1, thereby jointly forming an integrated structure of the fuel injector sleeve 1 and the glow plug. At the position where the copper sleeve contacts the fuel injector nozzle, an adiabatic coating is applied to reduce the increase in the heat load of the fuel injector nozzle caused by the heating of the glow plug. At the same time, since there is cooling water around the fuel injector nozzle and the glow plug, the influence of the glow plug heating on the fuel injector nozzle can be further offset.

[0049] Through the above settings, in specific applications, a glow plug and a spare glow plug are integrally installed on a methanol engine: the main glow plug is in a working state under normal operating conditions, and when it is detected that the main glow plug has a serious failure or cannot ensure the normal operation of the engine, it is switched to the spare glow plug. The control unit (ECU or independent controller) supplies power to the glow plug through the drive module. The glow plug current signal can be collected by a current sensor, and the engine exhaust temperature signal is collected by an engine exhaust temperature sensor, and the engine exhaust temperature sensor is arranged at the exhaust manifold position.

[0050] The control unit is built-in with a current calibration base map and an exhaust temperature calibration base map based on a predetermined operating condition (engine speed, fuel injection quantity); after filtering the glow plug current signal and the engine exhaust temperature signal collected by the sensor in real time, the above diagnostic steps are executed. In addition, a temperature control controller (model: PID-01) can also be installed to monitor and adjust the heating temperature of the glow plug in real time according to the in-cylinder combustion situation.

[0051] Embodiment 2 Based on the same inventive concept, this embodiment provides a fuel ignition fault diagnosis system for a hot surface assisted compression ignition methanol engine. The principle of solving the problem is similar to that of the fuel ignition fault diagnosis method for the hot surface assisted compression ignition methanol engine, and the repeated parts will not be described again.

[0052] This embodiment provides a fuel ignition fault diagnosis system for a hot surface assisted compression ignition methanol engine, including: A signal acquisition module, configured to collect in real time the glow plug temperature signal, the glow plug current signal, and the engine exhaust temperature signal during the operation of the methanol engine; wherein, the glow plug temperature signal is collected by the ceramic body at the head of the glow plug. A fault diagnosis module, configured to: If the glow plug temperature signal exists, the glow plug current signal is normal, and the engine exhaust temperature signal is normal, it is diagnosed that the methanol engine is operating normally; wherein, if the deviation between the processed glow plug current signal and the current calibration base map exceeds a preset current threshold, it is determined to be abnormal, otherwise it is normal; if the deviation between the processed engine exhaust temperature signal and the exhaust temperature calibration base map exceeds a preset temperature threshold, it is determined to be abnormal, otherwise it is normal. If the glow plug temperature signal exists, the glow plug current signal is abnormal, and the engine exhaust temperature signal is normal, if the glow plug current signal is abnormal and low, it is diagnosed that the heating function of the glow plug is abnormal, and if the glow plug current signal is abnormal and high, it is diagnosed that the heating circuit of the glow plug is overloaded. If the glow plug temperature signal is lost, the glow plug current signal is normal, and the engine exhaust temperature signal is normal, it is diagnosed that the temperature feedback circuit of the glow plug is abnormal. If the glow plug temperature signal exists, the glow plug current signal is abnormal, and the engine exhaust temperature signal is abnormal, if the engine exhaust temperature signal is abnormal and low, it is diagnosed that the heating function of the glow plug is abnormal, and if the engine exhaust temperature signal is abnormal and high, it is diagnosed that the heating circuit of the glow plug is overloaded. If the glow plug temperature signal is lost, the glow plug current signal is normal, and the engine exhaust temperature signal is abnormal, it is diagnosed that the ceramic body at the head of the glow plug is partially damaged but not broken. If the glow plug temperature signal is lost, the glow plug current signal is abnormal, and the engine exhaust temperature signal is abnormal, it is diagnosed that the ceramic body at the head of the glow plug is broken.

[0053] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memory, CD-ROM, optical memory, etc.) that contain computer-usable program code.

[0054] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be realized by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate means for realizing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0055] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including instruction means that realizes the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0056] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for realizing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0057] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and are not restrictive. Although the present invention has been described in detail with reference to the examples, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A method for diagnosing fuel ignition faults in a hot surface assisted compression ignition methanol engine, characterized in that: include: During the operation of the methanol engine, the glow plug temperature signal, the glow plug current signal and the engine exhaust temperature signal are collected in real time; wherein the glow plug temperature signal is collected by the ceramic body of the glow plug head; In response to the existence of the glow plug temperature signal, the normal glow plug current signal, and the normal engine exhaust temperature signal, it is diagnosed that the methanol engine is operating normally; wherein, if the deviation of the processed glow plug current signal from the current calibration base map exceeds a preset current threshold, it is determined to be abnormal, otherwise it is normal; if the deviation of the processed engine exhaust temperature signal from the exhaust temperature calibration base map exceeds a preset temperature threshold, it is determined to be abnormal, otherwise it is normal; In response to the glow plug temperature signal being present, the glow plug current signal being abnormal, and the engine exhaust temperature signal being normal, if the glow plug current signal is abnormal and on the low side, it is diagnosed that the heating function of the glow plug is abnormal, and if the glow plug current signal is abnormal and on the high side, it is diagnosed that the heating circuit of the glow plug is overloaded; In response to the glow plug temperature signal being lost, the glow plug current signal being normal, and the engine exhaust temperature signal being normal, diagnosing that a temperature feedback circuit of the glow plug is abnormal; In response to the existence of the glow plug temperature signal, the abnormal glow plug current signal, and the abnormal engine exhaust temperature signal, if the engine exhaust temperature signal is abnormal and low, it is diagnosed that the heating function of the glow plug is abnormal, and if the engine exhaust temperature signal is abnormal and high, it is diagnosed that the heating circuit of the glow plug is overloaded; In response to the glow plug temperature signal being lost, the glow plug current signal being normal, and the engine exhaust temperature signal being abnormal, it is diagnosed that the ceramic body of the glow plug head is partially damaged but not broken; In response to the glow plug temperature signal being lost, the glow plug current signal being abnormal, and the engine exhaust temperature signal being abnormal, it is diagnosed that the ceramic body of the glow plug head is broken.

2. The method for diagnosing fuel ignition faults of a hot surface assisted compression ignition methanol engine according to claim 1, characterized in that: In response to the glow plug temperature signal being present, the glow plug current signal being abnormal, and the engine exhaust temperature signal being normal, or in response to the glow plug temperature signal being lost, the glow plug current signal being normal, and the engine exhaust temperature signal being normal, an alarm is triggered.

3. The method for diagnosing fuel ignition faults of a hot surface assisted compression ignition methanol engine according to claim 1, characterized in that: Also includes: A spare glow plug is installed in the methanol engine, and the spare glow plug does not work when the engine is operating normally; In response to the existence of the glow plug temperature signal, the abnormality of the glow plug current signal, and the abnormality of the engine exhaust temperature signal, switching to the backup glow plug and triggering an alarm.

4. The method for diagnosing fuel ignition faults of a hot surface assisted compression ignition methanol engine according to claim 1, characterized in that: In response to the glow plug temperature signal being lost, the glow plug current signal being normal, and the engine exhaust temperature signal being abnormal, an emergency stop is triggered.

5. The method for diagnosing fuel ignition faults of a hot surface assisted compression ignition methanol engine according to claim 1, characterized in that: In response to the glow plug temperature signal being lost, the glow plug current signal being abnormal, and the engine exhaust temperature signal being abnormal, an emergency stop is triggered.

6. The method for diagnosing fuel ignition faults of a hot surface assisted compression ignition methanol engine according to claim 1, characterized in that: The glow plug and the injector sleeve are integrated into one structure, comprising: The fuel injector sleeve comprises a receiving cavity for arranging the fuel injector and an end wall located at one side of the receiving cavity, wherein a central hole is penetrated through the end wall, and the end wall is provided with at least one through hole distributed around the central hole; A mounting sleeve, which is mounted in the accommodating cavity, wherein the mounting sleeve comprises an accommodating hole corresponding to the through hole; A heating body, comprising a mounting end and a heating end, wherein the mounting end extends into and is connected to the receiving hole, and the heating end extends out of the through hole; A heat insulating coating is provided at a position where the outer surface of the mounting sleeve contacts the fuel injector.

7. The method for diagnosing fuel ignition faults of a hot surface assisted compression ignition methanol engine according to claim 6, characterized in that: The mounting sleeve is provided with one mounting sleeve hole corresponding to the position of the central hole, and the accommodating holes are distributed around the mounting sleeve hole; or, the mounting sleeve is provided with multiple mounting sleeve holes, and the multiple mounting sleeve holes are respectively provided with accommodating holes corresponding to the through holes.

8. A hot surface assisted compression ignition methanol engine fuel ignition fault diagnosis system, characterized in that: include: A signal acquisition module, used for real-time acquisition of glow plug temperature signals, glow plug current signals and engine exhaust temperature signals during the operation of the methanol engine; wherein the glow plug temperature signals are acquired by the ceramic body of the glow plug head; Fault diagnosis module for: In response to the existence of the glow plug temperature signal, the normal glow plug current signal, and the normal engine exhaust temperature signal, it is diagnosed that the methanol engine is operating normally; wherein, if the deviation of the processed glow plug current signal from the current calibration base map exceeds a preset current threshold, it is determined to be abnormal, otherwise it is normal; if the deviation of the processed engine exhaust temperature signal from the exhaust temperature calibration base map exceeds a preset temperature threshold, it is determined to be abnormal, otherwise it is normal; In response to the glow plug temperature signal being present, the glow plug current signal being abnormal, and the engine exhaust temperature signal being normal, if the glow plug current signal is abnormal and on the low side, it is diagnosed that the heating function of the glow plug is abnormal, and if the glow plug current signal is abnormal and on the high side, it is diagnosed that the heating circuit of the glow plug is overloaded; In response to the glow plug temperature signal being lost, the glow plug current signal being normal, and the engine exhaust temperature signal being normal, diagnosing that a temperature feedback circuit of the glow plug is abnormal; In response to the existence of the glow plug temperature signal, the abnormal glow plug current signal, and the abnormal engine exhaust temperature signal, if the engine exhaust temperature signal is abnormal and low, it is diagnosed that the heating function of the glow plug is abnormal, and if the engine exhaust temperature signal is abnormal and high, it is diagnosed that the heating circuit of the glow plug is overloaded; In response to the glow plug temperature signal being lost, the glow plug current signal being normal, and the engine exhaust temperature signal being abnormal, it is diagnosed that the ceramic body of the glow plug head is partially damaged but not broken; In response to the glow plug temperature signal being lost, the glow plug current signal being abnormal, and the engine exhaust temperature signal being abnormal, it is diagnosed that the ceramic body of the glow plug head is broken.

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