A method for evaluating local knock in premixed combustion engines

Abstract

The present invention discloses a method for evaluating local knock of a premixed combustion engine, and belongs to the field of engine technology. The method comprises the following steps: using a three-dimensional simulation program to calibrate the engine cylinder pressure to obtain a three-dimensional simulation model that can accurately describe the combustion process; based on the three-dimensional simulation model, making slices of pressure difference coupled temperature contour lines to describe the pressure oscillation process, and preliminarily determining the mechanism of knock according to the appearance position and motion state of the high-pressure area in the slice; based on the three-dimensional simulation model, making an OH slice diagram, and using temperature contour lines to describe the position of the flame surface, and further determining the mechanism of knock; based on the three-dimensional simulation model, deriving a heat release rate curve according to cylinder pressure data to assist in identifying two knock mechanisms. The present invention uses simulation and data analysis to quickly and accurately identify engine knock, help optimize the combustion process, improve engine performance and safety, while reducing emissions and costs, and promoting the development of environmental protection and intelligent technologies.

Description

Technical Field

[0001] The invention relates to an evaluation method based on local knock of a premixed combustion engine, belonging to the technical field of engines. Background Art

[0002] Knock is an abnormal combustion phenomenon of the engine, which is manifested as a violent oscillation of the pressure in the cylinder, which often causes damage to the engine. Therefore, it is very important to understand the mechanism of knock and implement the corresponding knock suppression strategy based on the essence of the mechanism. Generally speaking, knock is caused by the spontaneous combustion of the gas fuel at the end, which produces pressure oscillation and then triggers the knock phenomenon. For this type of knock, it is generally adopted to reduce the temperature of the end gas, such as adding EGR, or increase the propagation speed of the flame surface, so that the flame surface propagates before the end gas spontaneously ignites. However, the occurrence of knock is not always caused by the spontaneous combustion of the end gas. The rapid combustion of the local flame surface can also produce severe pressure oscillation, that is, the knock phenomenon. This knock is caused by the uneven distribution of local pressure in the cylinder, such as the impact of the jet flame will cause a local high-pressure area. Afterwards, when the high-pressure area passes through the flame surface with strong local combustion, the pressure difference between the high-pressure area and the low-pressure area is further increased. Finally, a violent pressure oscillation, that is, the knock phenomenon, is formed. For this type of knock mechanism, it is necessary to avoid the local rapid combustion phenomenon. At this time, slightly reducing the propagation speed of the flame surface can significantly reduce the knock intensity of this type of knock.

[0003] Therefore, it is necessary to identify the knock type so as to implement corresponding knock suppression strategies according to different knock mechanisms. Summary of the invention

[0004] The present invention proposes a method for evaluating local knock of a premixed combustion engine to solve the problem of lack of an evaluation method for distinguishing knock mechanisms in the prior art.

[0005] A method for evaluating local knock of a premixed combustion engine, the method comprising the following steps:

[0006] S100, calibrating the engine cylinder pressure using a three-dimensional simulation program to obtain a three-dimensional simulation model that can accurately describe the combustion process;

[0007] S200, based on the three-dimensional simulation model, making slices of pressure difference coupled temperature contour lines to describe the pressure oscillation process, and preliminarily determining the mechanism of knock according to the appearance position and movement state of the high-pressure area in the slices;

[0008] S300, based on the three-dimensional simulation model, making an OH slice diagram, and using temperature contour lines to describe the position of the flame surface, to further determine the mechanism of the knock;

[0009] S400: Based on the three-dimensional simulation model, derive a heat release rate curve according to cylinder pressure data to assist in identifying two knock mechanisms.

[0010] Further, in S100, the three-dimensional simulation program is CONVERGE.

[0011] Further, in S200, the slice of the pressure difference coupled temperature contour line includes a top view slice diagram of the pressure difference coupled temperature contour line of the engine.

[0012] Furthermore, in S200,

[0013] If a sudden increase in the local high-pressure area is observed on the pressure difference slice, and the movement of the high-pressure area presents reciprocating oscillations, especially near the unburned end gas area, the detonation type is preliminarily determined to be end gas spontaneous combustion detonation;

[0014] If the high-pressure area gradually strengthens after passing through the flame surface and shows a rotational motion around the cylinder, and at the same time the high-pressure area and the low-pressure area are symmetrically distributed in the cylinder, the detonation type is preliminarily determined to be rapid flame surface detonation.

[0015] Furthermore, in S300,

[0016] If a high-concentration OH area is observed to suddenly appear on the flame surface or at the far end of the flame surface in the pressure surge area, the detonation type is further determined to be end gas spontaneous combustion detonation;

[0017] If it is observed that high-concentration OH is not distributed at the end gas position far away from the flame surface, but is distributed near the flame surface, the detonation type is further determined to be fast flame surface detonation.

[0018] Furthermore, in S400,

[0019] If a steep peak appears on the heat release rate curve, the auxiliary judgment of the knock type is end gas spontaneous combustion knock;

[0020] If the heat release rate curve develops smoothly, it is used to assist in determining that the detonation type is fast flame surface detonation.

[0021] Furthermore, in S200-S400, based on the position and area of ​​the high-pressure area in the slice of the pressure difference coupled temperature contour line, the OH concentration distribution in the OH slice diagram and the peak characteristics of the heat release rate curve, the machine learning algorithm is used to identify the knock type and automatically determine the knock type.

[0022] Furthermore, in S200, it also includes dynamically tracking and time series analyzing the local high-pressure area in the slice based on the pressure difference coupled temperature contour line to determine the dynamic characteristics of the formation and dissipation of the high-pressure area;

[0023] In S300, it also includes quantitative analysis of the temporal and spatial variations of OH concentration to evaluate the speed and efficiency of flame surface propagation;

[0024] In S400, the heat release rate curve is calibrated in combination with the operating parameters of the engine to adapt to the knock evaluation under different working conditions. The operating parameters of the engine include speed, load and fuel composition.

[0025] A storage medium stores a computer program, which, when executed by a processor, implements the above-mentioned method for evaluating local knock of a premixed combustion engine.

[0026] A computer device comprises: a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the above-mentioned method for evaluating local knock of a premixed combustion engine.

[0027] Beneficial effects of the present invention: The present invention provides a method for evaluating local knock in a premixed combustion engine. The method for evaluating local knock in a premixed combustion engine achieves rapid and accurate identification of the knock type through precise three-dimensional simulation models, detailed pressure difference and OH concentration slice analysis, and derivation of heat release rate curves. It not only deepens the understanding of the knock mechanism, but also provides a scientific basis for formulating effective knock suppression strategies. The implementation of the present invention can significantly improve the performance and reliability of the engine, reduce emissions, improve fuel economy, extend engine life, and enhance operational safety. In addition, the present invention supports the research and development of new fuels and combustion technologies, promotes the development of intelligent technologies, reduces development costs, accelerates the research and development process, and makes engine operation more environmentally friendly and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is the slice image result of the pressure difference coupled temperature contour line to determine the detonation mechanism, where: Figure 1 (a) is the pressure difference coupled temperature contour slice image result of end gas spontaneous detonation; Figure 1 (b) is the pressure difference coupled temperature contour slice image result of fast flame surface detonation;

[0029] Figure 2 To further confirm the detonation mechanism using OH coupled temperature contour slices, the slice image results are shown in Figure 2. Figure 2 (a) is the OH coupling temperature contour slice image result of end gas spontaneous detonation; Figure 2 (b) is the OH coupling temperature contour slice image result of fast flame surface detonation;

[0030] Figure 3It is a heat release rate curve diagram that uses the heat release rate to assist in determining the mechanism of knock occurrence, where: Figure 3 (a) is the heat release rate curve image result of end gas spontaneous combustion detonation; Figure 3 (b) is the heat release rate curve image result of fast flame surface detonation;

[0031] Figure 4 The present invention is a flow chart of a method for evaluating local knock in a premixed combustion engine. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Reference Figure 4 As shown, a method for evaluating local knock of a premixed combustion engine, the method for evaluating local knock of a premixed combustion engine comprises the following steps:

[0034] S100, calibrating the engine cylinder pressure using a three-dimensional simulation program to obtain a three-dimensional simulation model that can accurately describe the combustion process;

[0035] S200, based on the three-dimensional simulation model, making slices of pressure difference coupled temperature contour lines to describe the pressure oscillation process, and preliminarily determining the mechanism of knock according to the appearance position and movement state of the high-pressure area in the slices;

[0036] S300, based on the three-dimensional simulation model, making an OH slice diagram, and using temperature contour lines to describe the position of the flame surface, to further determine the mechanism of the knock;

[0037] S400: Based on the three-dimensional simulation model, derive a heat release rate curve according to cylinder pressure data to assist in identifying two knock mechanisms.

[0038] Since there is no sudden and violent local combustion in non-terminal gas spontaneous combustion detonation, the oscillation of the high-pressure area tends to increase gradually and change slowly, and the area in contact with the flame surface shows obvious enhancement. The detonation caused by spontaneous combustion is due to the sudden and violent combustion at the end, and the high-pressure area will suddenly appear and oscillate back and forth. Therefore, different mechanisms cause different performances, which is an obvious feature that can distinguish the two.

[0039] However, the above characteristics cannot completely determine the type of detonation, because the most fundamental difference between end-gas spontaneous combustion detonation and non-end-gas spontaneous combustion detonation is whether end-gas spontaneous combustion occurs. Therefore, the S300 determination method is added to finally determine whether end-gas spontaneous combustion occurs. At the same time, it is difficult to find end-gas spontaneous combustion in three-dimensional space, and it is necessary to rely on the S200 method to find the end-gas spontaneous combustion location. Therefore, a two-stage method is proposed. The above two methods not only complement each other, but also indirectly reflect the different characteristics of the two types of detonation.

[0040] Therefore, S200 can provide reference information for S300. Because the area where spontaneous combustion occurs often brings local high pressure, but the local high pressure is not necessarily caused by spontaneous combustion. Therefore, it is easier to find the spontaneous combustion location at the location where the high pressure area appears after finding the high pressure area first. The S400 method is a common feature of end gas spontaneous combustion detonation. As a supplementary auxiliary judgment method, it further verifies the correctness of the judgment results of S200 and S300.

[0041] The premixed combustion engine local knock evaluation method of the present invention realizes the accurate calibration of the engine cylinder pressure through the establishment and analysis of the three-dimensional simulation model, and then accurately identifies and distinguishes different knock mechanisms through the comprehensive application of pressure difference coupled temperature contour line slices, OH slice diagrams and heat release rate curves. This method not only improves the accuracy of knock diagnosis, optimizes the combustion process, reduces the risk of engine damage, but also improves fuel economy and safety, reduces harmful emissions, supports the development of new technologies, accelerates product iterations, adapts to variable operating conditions, and reduces R&D costs through data-driven decision-making, overall improves engine performance and environmental standards, and enhances R&D efficiency and reliability.

[0042] Further, in S100, the three-dimensional simulation program is CONVERGE.

[0043] Specifically, CONVERGE was designated as the 3D simulation program because of its professionalism and efficiency, which can provide accurate combustion process simulation and cylinder pressure calibration, accelerate simulation calculations and reduce resource consumption. CONVERGE's user-friendly interface and advanced combustion models make it a preferred tool in research and development. At the same time, its compatibility and scalability support multidisciplinary collaboration and data integration. In addition, the software's rich case library and literature support help users quickly master applications, promote new technology research and development, and maximize cost-effectiveness, thereby accelerating the innovation and optimization of premixed combustion engine design while improving the accuracy of knock diagnosis.

[0044] Of course, this embodiment only takes CONVERGE as the preferred embodiment, and the method of the present invention is not limited to the use of other three-dimensional simulation programs.

[0045] Further, in S200, the slice of the pressure difference coupled temperature contour line includes a top view slice diagram of the pressure difference coupled temperature contour line of the engine.

[0046] Specifically, by including the top-view slice diagram of the pressure difference coupled temperature contour in the evaluation method, the pressure distribution and temperature field in the engine cylinder can be analyzed more intuitively and accurately. The two-dimensional slice diagram provides a top-view perspective, which helps to identify and track the formation and dynamic changes of the high-pressure area in the cylinder, especially in the combustion chamber, which is crucial for understanding the origin and characteristics of the knock phenomenon. In addition, combined with the temperature contour, the propagation path and speed of the flame surface can be observed more clearly, and then a more accurate judgment can be made on the knock mechanism. This method not only enhances the spatial cognition of the knock phenomenon, but also simplifies the identification process of the knock type through intuitive image information, thereby improving the efficiency and reliability of knock evaluation.

[0047] Furthermore, in S200,

[0048] If a sudden increase in the local high-pressure area is observed on the pressure difference slice, and the movement of the high-pressure area presents reciprocating oscillations, especially near the unburned end gas area, the detonation type is preliminarily determined to be end gas spontaneous combustion detonation;

[0049] If the high-pressure area gradually strengthens after passing through the flame surface and shows a rotational motion around the cylinder, and at the same time the high-pressure area and the low-pressure area are symmetrically distributed in the cylinder, the detonation type is preliminarily determined to be rapid flame surface detonation.

[0050] Specifically, refer to Figure 1 As shown, the pressure difference slice is drawn, and the temperature contour is used to describe the position of the flame surface. According to the resonance principle of the cylindrical combustion chamber, the top view slice can more vividly describe the pressure oscillation process. The range of the pressure difference can be determined according to the degree of oscillation of the cylinder pressure. According to the appearance position and movement state of the high-pressure area in the pressure difference slice, the mechanism of the knock can be preliminarily determined. If the high-pressure area suddenly appears near the unburned end gas, and the high-pressure area then makes a horizontal reciprocating oscillation movement in the cylinder, it is preliminarily determined to be a knock caused by the spontaneous combustion of the end gas. If the high-pressure area persists and is significantly enhanced after passing through the flame front, and in addition, the high-pressure area rotates around the cylinder, it is preliminarily determined to be a knock caused by the rapid flame surface.

[0051] In S200, by carefully analyzing the top view slice diagram of the pressure difference coupled temperature contour, the method of the present invention can intuitively reveal the pressure distribution and flame surface position in the cylinder, and accurately identify the two mechanisms of end gas spontaneous combustion detonation and rapid flame surface detonation. This not only improves the accuracy of knock diagnosis and helps to take more effective suppression measures, but also promotes the optimization of engine performance, reduces harmful emissions, enhances operating safety, and improves R&D efficiency, thus bringing significant benefits in engine design, performance improvement, and environmental protection and emission reduction.

[0052] Furthermore, in S300,

[0053] If a high-concentration OH area is observed to suddenly appear on the flame surface or at the far end of the flame surface in the pressure surge area, the detonation type is further determined to be end gas spontaneous combustion detonation;

[0054] If it is observed that high-concentration OH is not distributed at the end gas position far away from the flame surface, but is distributed near the flame surface, the detonation type is further determined to be fast flame surface detonation.

[0055] Specifically, refer to Figure 2 As shown, OH slices are drawn to further confirm the mechanism of detonation, and temperature contours are used to describe the position of the flame surface. In the detonation caused by end gas spontaneous combustion, there is often a large area with high concentration of OH distribution at the position where the high pressure area suddenly appears, and this area is located at the end gas position far away from the flame surface. In the detonation caused by the fast flame surface, there is no high concentration of OH distribution at the end gas position far away from the flame surface, and the high concentration of OH distribution is often near the flame surface.

[0056] In S300, by analyzing the OH slice diagram and combining the flame surface position described by the temperature contour line, the method of the present invention can accurately distinguish between end gas self-ignition detonation and fast flame surface detonation, significantly improving the accuracy of knock identification. This method not only provides intuitive chemical reaction evidence and a clear image of flame propagation for knock suppression, but also helps to optimize engine performance, improve fuel economy, reduce harmful emissions, extend engine life, and enhance operational safety. In addition, this technical means supports knock analysis under different operating conditions, promotes innovation in engine design and combustion process research, and ensures data-driven and reliable decision-making processes.

[0057] Furthermore, in S400,

[0058] If a steep peak appears on the heat release rate curve, the auxiliary judgment of the knock type is end gas spontaneous combustion knock;

[0059] If the heat release rate curve develops smoothly, it is used to assist in determining that the detonation type is fast flame surface detonation.

[0060] Specifically, refer to Figure 3 As shown, the heat release rate curve derived from the cylinder pressure can be used to assist in determining the knock mechanism. Generally speaking, end gas spontaneous combustion often suddenly forms a large amount of heat release, so there is a steep peak on the heat release rate curve. Therefore, if the heat release rate has a steep peak, it can be further determined as end gas spontaneous combustion knock. Conversely, in the case of fast flame surface knock, the flame surface burns sequentially. Therefore, if the heat release rate curve develops smoothly, it is a fast flame surface knock.

[0061] In S400, through the heat release rate curve derived from the cylinder pressure data, the method of the present invention can assist in determining whether the knock type is end gas spontaneous combustion knock or fast flame surface knock by identifying the steep peak or smooth development trend on the curve. This method significantly improves the accuracy of knock mechanism identification and provides direct heat release evidence for optimizing knock suppression strategies. It not only enhances combustion efficiency and engine performance, but also helps reduce harmful emissions, extend engine life, and improve operational safety. In addition, this technical means supports knock analysis under different operating conditions, promotes innovation in engine design and combustion process research, ensures data-driven and reliable decision-making processes, and provides a powerful analytical tool for the development of engine technology.

[0062] Furthermore, in S200-S400, based on the position and area of ​​the high-pressure area in the slice of the pressure difference coupled temperature contour line, the OH concentration distribution in the OH slice diagram and the peak characteristics of the heat release rate curve, the machine learning algorithm is used to identify the knock type and automatically determine the knock type.

[0063] Specifically, in steps S200-S400, by combining the slices of the pressure difference coupled temperature contour, the OH slice diagram and the heat release rate curve, and applying the machine learning algorithm, this method realizes the automation and high-precision identification of the knock type. This not only greatly improves the efficiency and accuracy of knock diagnosis, but also enhances the generalization ability of the model through data-driven decision support, allowing real-time monitoring and early warning, optimizing engine control, reducing R&D costs, and improving engine performance. In addition, this method reduces harmful emissions, extends engine life, and enhances operational safety. At the same time, it adapts to different operating conditions, promotes the development of engine intelligent technology, and provides an innovative solution for knock control and performance improvement of premixed combustion engines.

[0064] Furthermore, in S200, it also includes dynamically tracking and time series analyzing the local high-pressure area in the slice based on the pressure difference coupled temperature contour line to determine the dynamic characteristics of the formation and dissipation of the high-pressure area;

[0065] In S300, it also includes quantitative analysis of the temporal and spatial variations of OH concentration to evaluate the speed and efficiency of flame surface propagation;

[0066] In S400, the heat release rate curve is calibrated in combination with the operating parameters of the engine to adapt to the knock evaluation under different working conditions. The operating parameters of the engine include speed, load and fuel composition.

[0067] Specifically, in steps S200, S300, and S400, this method significantly improves the accuracy and adaptability of knock evaluation by dynamically tracking local high-pressure areas, quantitatively analyzing the spatiotemporal changes in OH concentration, and calibrating the heat release rate curve in combination with engine operating parameters. This not only enhances the understanding of the dynamic characteristics of the knock phenomenon and optimizes the evaluation of flame surface propagation, but also makes the knock suppression strategy more personalized and precise. In addition, this method improves combustion efficiency, reduces harmful emissions, extends engine life, and enhances operational safety. At the same time, it also improves R&D efficiency, promotes the development of intelligent control technology, and ensures the data-driven and reliable decision-making process, providing an advanced technical means for knock control and performance optimization of premixed combustion engines.

[0068] A storage medium stores a computer program, which, when executed by a processor, implements the above-mentioned method for evaluating local knock of a premixed combustion engine.

[0069] Specifically, the computer program stored on the storage medium, when executed by the processor, can automatically and efficiently implement the evaluation method of local knock in a premixed combustion engine, significantly improving the accuracy and efficiency of knock diagnosis. This method reduces manual intervention and enhances the repeatability and reliability of the results through precise data analysis and calculation. At the same time, it also reduces R&D costs and speeds up the R&D process. It has good versatility and applicability and is easy to update and expand to meet new research needs. In addition, the program can also be used as an education and training tool to help understand and master knock evaluation technology, promote technological innovation, and promote the environmental friendliness of engine operation.

[0070] A computer device comprises: a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the above-mentioned method for evaluating local knock of a premixed combustion engine.

[0071] Specifically, the computer device, equipped with memory, processor and dedicated computer program, realizes an efficient and automated method for evaluating local knock in premixed combustion engines. It simplifies the knock analysis process and improves the accuracy and efficiency of the evaluation through fast data processing and computing power. In addition, the design of the device has good flexibility and scalability, and can adapt to changing research needs and technological advances. It not only reduces R&D costs, but also has versatility and is suitable for various engine types. At the same time, as an education and training tool, it helps to cultivate professionals in related fields. In addition, by optimizing the combustion process, the device helps to reduce environmental impact and promotes the environmental protection and sustainable development of engine technology.

[0072] The present invention provides a method for evaluating local knock in a premixed combustion engine. The method for evaluating local knock in a premixed combustion engine achieves rapid and accurate identification of the knock type through an accurate three-dimensional simulation model, detailed pressure difference and OH concentration slice analysis, and derivation of a heat release rate curve. It not only deepens the understanding of the knock mechanism, but also provides a scientific basis for formulating effective knock suppression strategies. The implementation of the present invention can significantly improve the performance and reliability of the engine, reduce emissions, improve fuel economy, extend engine life, and enhance operational safety. In addition, the present invention supports the research and development of new fuels and combustion technologies, promotes the development of intelligent technologies, reduces development costs, accelerates the research and development process, and makes engine operation more environmentally friendly and efficient.

[0073] The above is a detailed introduction to the evaluation method of local knock of a premixed combustion engine provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for general technicians in this field, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A method for evaluating local knock in a premixed combustion engine, characterized in that: The method for evaluating local knock in a premixed combustion engine comprises the following steps: S100, calibrating the engine cylinder pressure using a three-dimensional simulation program to obtain a three-dimensional simulation model that can accurately describe the combustion process; S200, based on the three-dimensional simulation model, making slices of pressure difference coupled temperature contour lines to describe the pressure oscillation process, and preliminarily determining the mechanism of knock according to the appearance position and movement state of the high-pressure area in the slices; S300, based on the three-dimensional simulation model, making a hydroxyl radical slice diagram, and using temperature contour lines to describe the position of the flame surface, to further determine the mechanism of the knock; S400, based on the three-dimensional simulation model, deriving a heat release rate curve according to cylinder pressure data to assist in identifying two knock mechanisms; In S200, the slices of the pressure difference coupled temperature contour lines include top-down slice diagrams of the pressure difference coupled temperature contour lines of the engine. The pressure distribution and temperature field in the engine cylinder are analyzed by using the top-down slice diagrams of the pressure difference coupled temperature contour lines. The top-down perspective provided by the two-dimensional slice diagram is used to identify and track the formation and dynamic changes of the high-pressure area in the combustion chamber in the cylinder. In addition, the propagation path and speed of the flame surface are observed in combination with the temperature contour lines, so as to make a judgment on the knock mechanism.

2. The method for evaluating local knock of a premixed combustion engine according to claim 1, characterized in that: In S100, the three-dimensional simulation program is CONVERGE.

3. The method for evaluating local knock of a premixed combustion engine according to claim 1, characterized in that: In S200, If it is observed on the pressure difference slice that the local high-pressure area suddenly increases, and the movement of the high-pressure area presents reciprocating oscillation, it is preliminarily determined that the detonation type is end gas spontaneous combustion detonation; If the high-pressure area gradually strengthens after passing through the flame surface and shows a rotational motion around the cylinder, and at the same time the high-pressure area and the low-pressure area are symmetrically distributed in the cylinder, the detonation type is preliminarily determined to be rapid flame surface detonation.

4. The method for evaluating local knock of a premixed combustion engine according to claim 3, characterized in that: In S300, If a high concentration of hydroxyl radicals is observed to suddenly appear on the flame surface or at the far end of the flame surface in the pressure surge area, the detonation type is further determined to be end gas spontaneous combustion detonation; If it is observed that high concentration of hydroxyl radicals are not distributed at the end gas position far away from the flame surface, but are distributed near the flame surface, the detonation type is further determined to be fast flame surface detonation.

5. The method for evaluating local knock of a premixed combustion engine according to claim 4, characterized in that: In S400, If a steep peak appears on the heat release rate curve, the auxiliary judgment of the knock type is end gas spontaneous combustion knock; If the heat release rate curve develops smoothly, it is used to assist in determining that the detonation type is fast flame surface detonation.

6. A method for evaluating local knock of a premixed combustion engine according to any one of claims 1 to 5, characterized in that: In S200-S400, based on the position and area of ​​the high-pressure zone in the slice of the pressure difference coupled temperature contour line, the hydroxyl radical concentration distribution in the hydroxyl radical slice diagram and the peak characteristics of the heat release rate curve, the machine learning algorithm is used to identify the knock type and automatically determine the knock type.

7. A method for evaluating local knock of a premixed combustion engine according to any one of claims 1 to 5, characterized in that: In S200, it also includes dynamically tracking and time series analyzing the local high-pressure area in the slice based on the pressure difference coupled temperature contour line to determine the dynamic characteristics of the formation and dissipation of the high-pressure area; In S300, it also includes quantitative analysis of the temporal and spatial changes in the concentration of hydroxyl radicals to evaluate the speed and efficiency of flame surface propagation; In S400, the heat release rate curve is calibrated in combination with the operating parameters of the engine to adapt to the knock evaluation under different working conditions. The operating parameters of the engine include speed, load and fuel composition.

8. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for evaluating local knock of a premixed combustion engine as described in any one of claims 1 to 7 is implemented.

9. A computer device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement a method for evaluating local knock of a premixed combustion engine as described in any one of claims 1 to 7.

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