A method, terminal and storage medium for establishing a three-dimensional simulation model of a combustion system based on discrete coordinate data

Abstract

The present invention belongs to the field of vehicle power technology, and specifically relates to a method, terminal and storage medium for establishing a three-dimensional simulation model of a combustion system based on discrete coordinate data, including discretizing a piston bowl profile constituting a combustion chamber based on a chord height and obtaining discrete coordinate data; importing the discrete coordinate data and engine parameters pre-stored in a database into a preset simulation tool based on an actual compression ratio to create a three-dimensional simulation model of a combustion system with a compensation volume; the present invention simplifies the modeling process of a traditional three-dimensional geometric solid model by discretizing the geometric shape of the combustion chamber; in view of the problem that the fuel injection data provided by an ECU is limited and is affected by the electromagnetic response characteristics of an injector, the present invention introduces a preset correction tool, and accurately corrects the injection timing and injection duration by comprehensively considering multiple factors such as the injector power-on time, the opening response time, and the engine speed.

Description

Technical Field

[0001] The present invention belongs to the field of vehicle power technology, and in particular relates to a method for establishing a three-dimensional simulation model of a combustion system based on discrete coordinate data, a terminal and a storage medium. Background Art

[0002] With the advancement of science and technology and the development of industry, the design and optimization of combustion systems play a vital role in the field of internal combustion engines. In order to meet increasingly stringent environmental requirements and improve engine performance, various new combustion concepts and alternative fuels are being continuously developed and researched. However, these innovations have brought unprecedented challenges to the design and optimization of combustion systems.

[0003] Traditional combustion system design methods rely on detailed three-dimensional geometric solid models of the combustion chamber. This process not only requires a lot of computing resources, but the modeling process is cumbersome and time-consuming, and it is difficult to adapt to the rapid iteration of engineering needs. In addition, due to the complexity of the fuel spray process, traditional simulation models often cannot accurately reflect the fuel injection and combustion process in the cylinder, which seriously affects the accuracy of the simulation results.

[0004] Specifically, the fuel injection data that the ECU (electronic control unit) can provide is limited, and due to the influence of the electromagnetic response characteristics of the injector, it is often impossible to obtain accurate injection timing, injection duration and injection law curve. This causes the simulation model to have large errors when simulating the in-cylinder fuel injection process, which in turn affects the accurate prediction of the combustion process and pollutant generation. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides a method, a terminal and a storage medium for establishing a three-dimensional simulation model of a combustion system based on discrete coordinate data to solve the above-mentioned technical problems.

[0006] In a first aspect, the present invention provides a method for establishing a three-dimensional simulation model of a combustion system based on discretized coordinate data, comprising: Discretize the piston bowl line constituting the combustion chamber based on the chord height and obtain discrete coordinate data; Based on the actual compression ratio, the discrete coordinate data and the engine parameters stored in the database are imported into the preset simulation tool to create a three-dimensional simulation model of the combustion system with compensation volume; Input the injector power-on time, engine speed, power-on duration obtained from the ECU, and the injector opening response time and injection duration extension time obtained from the database and provided by the injector manufacturer into the preset correction tool to correct the injection time and injection duration obtained from the ECU; Input the corrected injection duration and the rail pressure and cycle injection amount obtained from the ECU into the preset curve generation tool, adjust the injector flow coefficient and calculate the injection law curve; The engine parameters stored in the database and the corrected injection timing, injection duration, injector flow coefficient and injection law curve are input into the created three-dimensional simulation model of the combustion system, and the simulation results are calculated and output; the bench measured data and the simulation results are compared and analyzed, and the injector response delay time and injection duration extension time are adjusted according to the comparative analysis results until the simulation result data are consistent with the bench measured data, and the calibration of the three-dimensional simulation model of the combustion system is completed, and the calibrated three-dimensional simulation model of the combustion system is output.

[0007] A further improvement of the technical solution is to discretize the piston bowl line constituting the combustion chamber based on the chord height and obtain discrete coordinate data, and the method specifically includes: Using a preset drawing tool to obtain combustion chamber piston bowl profile data based on a piston diagram in the combustion chamber to be simulated; Reconstruct the combustion chamber profile coordinate system with the combustion chamber center as the origin; Divide each curve segment in the combustion chamber profile coordinate system into equal parts based on the chord height; After equal division, the division points are highlighted by point style; Use polylines to capture segmentation points and curve connection points from the center of the combustion chamber to the radial end points of the combustion chamber in sequence; Select multiple curve segments and output the corresponding segmentation point coordinates until all segmentation point coordinates are output, that is, discrete coordinate data.

[0008] A further improvement of the technical solution is that the range of the chord height is: 0.0012≤chord height≤0.0066, and the unit is: millimeter.

[0009] A further improvement of the technical solution is that based on the actual compression ratio, the discrete coordinate data and the engine parameters pre-stored in the database are imported into a preset simulation tool to create a three-dimensional simulation model of the combustion system with a compensation volume, and the method specifically includes: Calculate the actual compression ratio of the engine based on the three-dimensional solid model of the engine; Obtaining pre-stored engine parameters from the database, including engine bore, stroke, connecting rod length, piston pin offset, compression clearance height, number of injector holes, piston land, and cylinder liner clearance; The discrete coordinate data and the engine parameters stored in the database are imported into the preset simulation tool, and a three-dimensional simulation model of the combustion system is created based on the actual compression ratio and the gap between the piston fire land and the cylinder liner as the compensation volume.

[0010] A further improvement of the technical solution is that the injector power-on time, engine speed, power-on time obtained from the ECU, and the injector opening response time and injection duration extension time obtained from the database and provided by the injector manufacturer are input into the preset correction tool to correct the injection time and injection duration obtained from the ECU, and the method specifically includes: Input the injector power-on time, engine speed, power-on duration obtained from the ECU, and the injector opening response time and injection duration extension time obtained from the database and provided by the injector manufacturer into the preset correction tool; The preset correction tool calculates the injection timing based on the power-on time, injector opening response time and engine speed, and corrects the injection timing obtained from the ECU; The preset correction tool calculates the injection duration based on the power-on duration, the injection duration extension time and the engine speed, and corrects the injection duration obtained from the ECU.

[0011] A further improvement of the technical solution is that the formula for calculating the injection time based on the power-on time, the injector opening response time and the engine speed is: ; in, It is the injection time; is the crankshaft angle at the time of power-on, in degrees / CA; n is the engine speed, in r / min; Injector opening response time, 0.3ms≤ ≤0.4ms.

[0012] A further improvement of the technical solution is that the calculation formula for calculating the injection duration based on the power-on time, the injection duration extension time and the engine speed is: ; in, is the injection duration, is the power-on duration, unit: ms; The injection duration is extended, unit: 0.16ms≤ ≤0.6ms.

[0013] Further improvements of the technical solution include: inputting the engine parameters pre-stored in the database and the corrected injection timing, injection duration, injector flow coefficient and injection law curve into the created three-dimensional simulation model of the combustion system, calculating and outputting the simulation results; and comparing and analyzing the bench measured data and the simulation results, adjusting the injector response delay time and the injection duration extension time according to the comparative analysis results until the simulation result data is consistent with the bench measured data, completing the calibration of the three-dimensional simulation model of the combustion system, and outputting the calibrated three-dimensional simulation model of the combustion system. The method specifically includes: Obtain engine bench test data at different engine speeds, including cylinder pressure data, hourly fuel consumption, intake volume, EGR rate, and piston temperature measurement data; The initial conditions are obtained through cylinder pressure data, including initial cylinder temperature and pressure, and the cylinder components are calculated through hourly fuel consumption, intake volume, and EGR rate; Setting boundary conditions based on piston temperature measurement data; According to the comparative analysis results of the cylinder pressure and heat release rate curves in the simulation results with the actual test bench data, the injector response delay time and the injection duration extension time are adjusted until the cylinder pressure data and the heat release rate curve are consistent with the actual test bench data. The calibration of the three-dimensional simulation model of the combustion system is completed, and the calibrated three-dimensional simulation model of the combustion system is output.

[0014] In a third aspect, a terminal is provided, including: processor, memory, wherein: The memory is used to store computer programs. The processor is used to call and run the computer program from the memory, so that the terminal executes the above-mentioned terminal method.

[0015] In a fourth aspect, a computer storage medium is provided, wherein the computer-readable storage medium stores instructions, and when the computer-readable storage medium is run on a computer, the computer executes the methods described in the above aspects.

[0016] The beneficial effects of the present invention are: Improve modeling efficiency and accuracy: By discretizing the combustion chamber geometry, the present invention simplifies the modeling process of the traditional three-dimensional geometric solid model and reduces the consumption of computing resources. At the same time, the use of discretized coordinate data makes the model more accurate and can more realistically reflect the actual situation of the combustion chamber, thereby improving the accuracy of the simulation results.

[0017] Optimizing the injection data correction method: In view of the problem that the fuel injection data provided by the ECU is limited and is affected by the electromagnetic response characteristics of the injector, the present invention introduces a preset correction tool to accurately correct the injection timing and injection duration by comprehensively considering multiple factors such as the injector power-on time, opening response time, engine speed, etc.; this method effectively improves the accuracy of the simulation model when simulating the in-cylinder fuel injection process.

[0018] Generate accurate injection law curve: Through the preset curve generation tool, the present invention can adjust the injector flow coefficient and calculate the accurate injection law curve according to the corrected injection duration, rail pressure, cycle injection amount and other parameters. This curve is of great significance for simulating the fuel distribution in the cylinder, the combustion process and the generation of pollutants, and further improves the accuracy and practicality of the simulation model.

[0019] Realize rapid model calibration and iteration: The present invention realizes rapid calibration of the three-dimensional simulation model of the combustion system by comparing and analyzing the bench measured data with the simulation results, and adjusting the parameters such as the injector response delay time and the injection duration extension time according to the comparative analysis results. This method not only improves the efficiency of model calibration, but also enables the model to adapt to changes in engineering requirements more quickly, and realizes rapid iteration and optimization.

[0020] In addition, the design principle of the present invention is reliable, the method is simple, and it has very broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 The present invention is a schematic flow chart of a method according to an embodiment of the present invention.

[0023] Figure 2 A line drawing of the combustion chamber pit profile at a specified origin.

[0024] Figure 3 This is a discrete afterburner profile diagram based on chord height.

[0025] Figure 4 It is the coordinate data of the discrete post-combustion chamber profile.

[0026] Figure 5 This is a three-dimensional model diagram of a combustion chamber with compensation volume.

[0027] Figure 6 This is the schematic diagram of the injector injection process.

[0028] Figure 7 This is the electromagnetic response characteristic diagram of the injector.

[0029] Figure 8 This is the relationship diagram between the injector opening delay and the power-on time under different rail pressures.

[0030] Fig. 9 This is the relationship diagram between injection duration and power-on time under different rail pressures.

[0031] Fig.10 A schematic diagram of the structure of a terminal provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described 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 should fall within the scope of protection of the present invention.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0034] The key terms appearing in the present invention are explained below.

[0035] ECU (Electronic Control Unit) is also called "driving computer" or "on-board computer". Like ordinary computers, it is composed of microprocessor (MCU), memory (ROM, RAM), input / output interface (I / O), analog-to-digital converter (A / D), and large-scale integrated circuits such as shaping and driving. The voltage operating range of ECU is generally 6.5-16V (there is a voltage stabilizer at the key point inside), the working current is 0.015-0.1A, and the working temperature is -40℃~80℃. It can withstand vibrations below 1000Hz, so the probability of ECU damage is very small. In ECU, CPU is the core part, which has the functions of calculation and control. When the engine is running, it collects signals from various sensors, performs calculations, and converts the results of the calculations into control signals to control the operation of the controlled object. It also controls the memory (ROM / FLASH / EEPROM, RAM), input / output interface (I / O) and other external circuits; the program stored in the memory ROM is written based on data obtained through precise calculations and a large number of experiments. This inherent program constantly compares and calculates with the signals collected from various sensors when the engine is working. The results of the comparison and calculation are used to control multiple parameters such as engine ignition, air-fuel ratio, idle speed, exhaust gas recirculation, etc.

[0036] The EGR (Exhaust Gas Recirculation) rate is defined as the ratio of the amount of recirculated exhaust gas to the total amount of intake air sucked into the cylinder. Reasonable control of the EGR rate is extremely important for the purification effect of nitrogen oxides and the emission of the whole machine. When conducting calibration tests, a method is needed to quantify the EGR rate to judge the impact of exhaust gas recirculation on engine performance.

[0037] The method for establishing a three-dimensional simulation model of a combustion system based on discretized coordinate data provided by an embodiment of the present invention is executed by a computer device.

[0038] Figure 1 The following is a schematic flow chart of a method according to an embodiment of the present invention. According to different requirements, the order of the steps in the flow chart can be changed, and some steps can be omitted.

[0039] like Figure 1 As shown, the method includes: Step 110, discretizing the piston bowl profile constituting the combustion chamber based on the chord height and obtaining discrete coordinate data; Step 120, based on the actual compression ratio, the discrete coordinate data and the engine parameters pre-stored in the database are imported into a preset simulation tool to create a three-dimensional simulation model of the combustion system with a compensation volume; Step 130, inputting the fuel injector power-on time, engine speed, power-on duration obtained from the ECU, and the fuel injector opening response time and fuel injection duration extension time obtained from the database and provided by the fuel injector manufacturer into a preset correction tool to correct the fuel injection time and fuel injection duration obtained from the ECU; Step 140, inputting the corrected injection duration and the rail pressure and cycle injection amount obtained from the ECU into a preset curve generation tool, adjusting the injector flow coefficient and calculating the injection regularity curve; Step 150, input the engine parameters pre-stored in the database and the corrected injection timing, injection duration, injector flow coefficient and injection law curve into the created three-dimensional simulation model of the combustion system, calculate and output the simulation results; and compare and analyze the bench measured data and the simulation results, adjust the injector response delay time and injection duration extension time according to the comparative analysis results, until the simulation result data is consistent with the bench measured data, complete the calibration of the three-dimensional simulation model of the combustion system, and output the calibrated three-dimensional simulation model of the combustion system.

[0040] To facilitate understanding of the present invention, the following is a further description of the method for establishing a three-dimensional simulation model of a combustion system based on discrete coordinate data provided by the present invention, based on the principle of the method for establishing a three-dimensional simulation model of a combustion system based on discrete coordinate data, combined with the process of performing three-dimensional simulation modeling of the combustion system based on discrete coordinate data in the embodiment.

[0041] The piston bowl line constituting the combustion chamber is discretized based on the chord height and discrete coordinate data is obtained. The method specifically includes: S111, using a preset drawing tool to obtain combustion chamber piston bowl line data based on a piston diagram in the combustion chamber to be simulated; S112. Reconstruct the combustion chamber profile coordinate system with the combustion chamber center as the origin through the UCS command; S113, using the DIV command, dividing each curve segment in the combustion chamber profile coordinate system into equal parts based on the chord height; S114, by using the DDPT command, the split points are highlighted by a point style after equal division; S115, using the PL command, using a polyline to sequentially capture the segmentation points and curve connection points from the center of the combustion chamber to the radial end point of the combustion chamber; S116. Use the LIST command to select multiple curve segments and output the corresponding segmentation point coordinates until all segmentation point coordinates are output, that is, discrete coordinate data.

[0042] like Figure 2As shown, the combustion chamber piston bowl profile data is obtained based on the piston diagram in the combustion chamber to be simulated using Autocad software, and the combustion chamber profile coordinate system is reconstructed using the combustion chamber center as the origin using Autocad software. The curves that make up the combustion chamber profile are divided equally based on the chord height (0.0012≤chord height≤0.0066, unit: mm), and the segmentation points are highlighted in a point style after the equal division. Polylines are used to capture the segmentation points and curve connection points from the center of the combustion chamber to the radial end points of the combustion chamber in sequence, as shown in FIG. Figure 3 As shown; finally, the polyline coordinates are output in sequence through the LIST command, and the (x, y) coordinates are the combustion chamber line coordinates, such as Figure 4 shown.

[0043] In addition, based on the actual compression ratio, the discrete coordinate data and the engine parameters pre-stored in the database are imported into a preset simulation tool to create a three-dimensional simulation model of the combustion system with a compensation volume, and the method specifically includes: S121, calculating the actual compression ratio of the engine based on the three-dimensional solid model of the engine (the actual compression ratio is calculated by obtaining the volume of the combustion chamber at the top dead center through the three-dimensional model of the engine); S122, obtaining pre-stored engine parameters from a database, including engine cylinder diameter, stroke, connecting rod length, piston pin offset, compression clearance height, number of injector holes, piston fire land, and cylinder liner clearance; S123, the discrete coordinate data and the engine parameters stored in the database are imported into a preset simulation tool (CONVERGE software Make engine sector surface tool), and a three-dimensional simulation model of the combustion system is created based on the actual compression ratio and the gap between the piston power bank and the cylinder liner as the compensation volume, such as Figure 5 shown.

[0044] In addition, the injector power-on time, engine speed, power-on duration obtained from the ECU, and the injector opening response time and injection duration extension time obtained from the database and provided by the injector manufacturer are input into the preset correction tool to correct the injection time and injection duration obtained from the ECU, and the method specifically includes: S131, inputting the injector power-on time, engine speed, power-on duration obtained from the ECU, and the injector opening response time and injection duration extension time obtained from the database and provided by the injector manufacturer into the preset correction tool; S132, the preset correction tool calculates the injection timing based on the power-on timing, the injector opening response time and the engine speed, and corrects the injection timing obtained from the ECU; S133, the preset correction tool calculates the injection duration based on the power-on time, the injection duration extension time and the engine speed, and corrects the injection duration obtained from the ECU.

[0045] Specifically, the formula for calculating the injection timing based on the power-on timing, the injector opening response time and the engine speed is: ; in, It is the injection time; is the crankshaft angle at the time of power-on, in degrees / CA; n is the engine speed, in r / min; Injector opening response time, 0.3ms≤ ≤0.4ms; The influence range of the injector response delay time on the injection timing is different at different speeds, as shown in Table 1: Table 1 The influence range of injector response delay time on injection timing at different speeds

[0047] Furthermore, the calculation formula for calculating the injection duration based on the power-on time, the injection duration extension time and the engine speed is: ; in, is the injection duration, is the power-on duration, unit: ms; The injection duration is extended, unit: 0.16ms≤ ≤0.6ms, at different speeds The impact range on the injection duration is also different, as shown in Table 2: Table 2 At different speeds Table of influence on injection duration

[0049] The quality of diesel engine combustion process depends largely on the spray process. Usually, the engine ECU data acquisition of injection data is limited, and only the injector power-on time, power-on duration, rail pressure, and cycle injection amount data can be obtained. According to the injector injection process principle, such as Figure 6 , Figure 7 As shown in the figure, there is an interval from the time the injector is powered on to the time the injector needle valve opens, which is called the injection opening delay. Tests show that the injection delay time of the high-pressure common rail system injector is usually about (0.3-0.4) ms. The injection delay time at different speeds corresponds to the following Figure 8 As shown, the actual injection advance angle needs to be adjusted according to the speed and the delay time of the injector opening. The injection timing adjustment range is shown in Table 1. The same delay also exists in the injector closing process. Therefore, the injection duration is not equal to the power-on duration. As the power-on duration increases, the difference between the injection duration and the power-on duration is about (0.16-0.6) ms. Fig. 9 The adjustment range of injection duration is shown in Table 2. In addition, the injection law also has a great influence on the combustion process, but the injection law of the injector often requires special experiments to obtain, the process is complicated and the cost is high. The simulation mainly adopts the trapezoidal injection law of slow first and fast later, and the rising and falling slopes and injection fluctuations cannot be accurately reflected. Therefore, the injection profile software is used to adjust the flow coefficient (0.5 to 0.87) to simulate the injection law, which greatly improves the accuracy of the injection law and reduces the influence of human factors.

[0050] In order to improve the accuracy of the created three-dimensional simulation model of the combustion system, the present invention also inputs the engine parameters pre-stored in the database and the corrected injection timing, injection duration, injector flow coefficient and injection law curve into the created three-dimensional simulation model of the combustion system, calculates and outputs the simulation results; and compares and analyzes the bench measured data and the simulation results, adjusts the injector response delay time and the injection duration extension time according to the comparison and analysis results, until the simulation result data is consistent with the bench measured data, completes the calibration of the three-dimensional simulation model of the combustion system, and outputs the calibrated three-dimensional simulation model of the combustion system, and the method specifically includes: S151, obtaining engine bench measured data at different engine speeds, the bench measured data including cylinder pressure data, hourly fuel consumption, intake volume, EGR rate, and piston temperature measurement data; S152, obtaining initial conditions through cylinder pressure data, the initial conditions including initial cylinder temperature and pressure, and calculating cylinder components through hourly fuel consumption, intake air volume, and EGR rate; S153, setting boundary conditions based on piston temperature measurement data; S154. According to the comparative analysis results of the cylinder pressure and heat release rate curves in the simulation results and the bench measured data, the injector response delay time and the injection duration extension time are adjusted until the cylinder pressure data and the heat release rate curve are consistent with the bench measured data, and the calibration of the combustion system three-dimensional simulation model is completed, and the calibrated combustion system three-dimensional simulation model is output.

[0051] Specifically, the closing time of the intake valve and the opening time of the exhaust valve are determined as the calculation start and end time according to the valve timing. The initial conditions in the cylinder at the intake time are determined according to the cylinder pressure and the corresponding calculated temperature curve, and the temperature boundary conditions of the simulation model are determined based on the piston temperature measurement test. The components in the cylinder are calculated based on the hourly fuel consumption, intake volume, and EGR rate. The heat transfer model, spray model, combustion model, turbulence model parameters, etc. are selected and set. The model selection is shown in Table 3. According to the simulation results, the injector response delay time, the injection duration extension time, that is, the injection time, injection duration, and injection law are appropriately adjusted until the test data and the simulation data are consistent, and the three-dimensional simulation model of the combustion system is output.

[0052] Table 3 Simulation model setting table

[0054] Fig.10 The present invention is a schematic diagram of the structure of a terminal 300 provided in an embodiment of the present invention. The terminal 300 can be used to execute the method for establishing a three-dimensional simulation model of a combustion system based on discretized coordinate data provided in an embodiment of the present invention.

[0055] The terminal 300 may include: a processor 310, a memory 320 and a communication module 330. These components communicate via one or more buses. Those skilled in the art will appreciate that the server structure shown in the figure does not limit the present invention, and it may be a bus structure or a star structure, and may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently.

[0056] The memory 320 can be used to store the execution instructions of the processor 310, and the memory 320 can be implemented by any type of volatile or non-volatile storage terminal or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk. When the execution instructions in the memory 320 are executed by the processor 310, the terminal 300 can perform some or all of the steps in the following method embodiments.

[0057] The processor 310 is the control center of the storage terminal, and uses various interfaces and lines to connect various parts of the entire electronic terminal. It runs or executes software programs and / or modules stored in the memory 320, and calls data stored in the memory to perform various functions of the electronic terminal and / or process data. The processor can be composed of an integrated circuit (IC), for example, it can be composed of a single packaged IC, or it can be composed of multiple packaged ICs with the same or different functions. For example, the processor 310 can only include a central processing unit (CPU). In the embodiment of the present invention, the CPU can be a single computing core or multiple computing cores.

[0058] The communication module 330 is used to establish a communication channel so that the storage terminal can communicate with other terminals, receive user data sent by other terminals or send user data to other terminals.

[0059] The present invention also provides a computer storage medium, wherein the computer storage medium may store a program, and when the program is executed, the program may include some or all of the steps in each embodiment provided by the present invention. The storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM).

[0060] Those skilled in the art can clearly understand that the technology in the embodiments of the present invention can be implemented by means of software plus a necessary general hardware platform. Based on this understanding, the technical solution in the embodiments of the present invention, in essence or in other words, the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a disk or an optical disk, and other media that can store program codes, including several instructions for enabling a computer terminal (which can be a personal computer, a server, or a second terminal, a network terminal, etc.) to execute all or part of the steps of the methods described in each embodiment of the present invention.

[0061] In this specification, the same or similar parts between the various embodiments can be referred to each other. In particular, for the terminal embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the description in the method embodiment.

[0062] In the several embodiments provided by the present invention, it should be understood that the disclosed systems and methods can be implemented in other ways. For example, the system embodiments described above are only schematic. For example, the division of the modules is only a logical function division. There may be other division methods in actual implementation, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of systems or modules, which can be electrical, mechanical or other forms.

[0063] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed on multiple network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0064] In addition, each functional module in each embodiment of the present invention may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module.

[0065] Although the present invention has been described in detail with reference to the accompanying drawings and in combination with the preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, a person of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and these modifications or substitutions shall be within the scope of the present invention. Any person of ordinary skill in the art may easily think of changes or substitutions within the technical scope disclosed by the present invention, and these shall be within the scope of protection of the present invention.

Claims

1. A method for establishing a three-dimensional simulation model of a combustion system based on discretized coordinate data, characterized in that: include: Discretize the piston bowl line constituting the combustion chamber based on the chord height and obtain discrete coordinate data; Based on the actual compression ratio, the discrete coordinate data and the engine parameters stored in the database are imported into the preset simulation tool to create a three-dimensional simulation model of the combustion system with compensation volume; Input the injector power-on time, engine speed, power-on duration obtained from the ECU, and the injector opening response time and injection duration extension time obtained from the database and provided by the injector manufacturer into the preset correction tool to correct the injection time and injection duration obtained from the ECU; Input the corrected injection duration and the rail pressure and cycle injection amount obtained from the ECU into the preset curve generation tool, adjust the injector flow coefficient and calculate the injection law curve; Input the engine parameters stored in the database and the corrected injection timing, injection duration, injector flow coefficient and injection law curve into the created three-dimensional simulation model of the combustion system, calculate and output the simulation results; The bench measured data and simulation results are compared and analyzed, and the injector response delay time and injection duration extension time are adjusted according to the comparative analysis results until the simulation result data are consistent with the bench measured data. The calibration of the combustion system three-dimensional simulation model is completed, and the calibrated combustion system three-dimensional simulation model is output.

2. The method for establishing a three-dimensional simulation model of a combustion system based on discretized coordinate data according to claim 1, characterized in that: Discretization of the piston bowl line constituting the combustion chamber is performed based on the chord height and discrete coordinate data is obtained, and the method specifically includes: Using a preset drawing tool to obtain combustion chamber piston bowl profile data based on a piston diagram in the combustion chamber to be simulated; Reconstruct the combustion chamber profile coordinate system with the combustion chamber center as the origin; Divide each curve segment in the combustion chamber profile coordinate system into equal parts based on the chord height; After equal division, the division points are highlighted by point style; Use polylines to capture segmentation points and curve connection points from the center of the combustion chamber to the radial end points of the combustion chamber in sequence; Select multiple curve segments and output the corresponding segmentation point coordinates until all segmentation point coordinates are output, that is, discrete coordinate data.

3. The method for establishing a three-dimensional simulation model of a combustion system based on discretized coordinate data according to claim 1, characterized in that: The range of chord height is: 0.0012≤chord height≤0.0066, unit: millimeter.

4. The method for establishing a three-dimensional simulation model of a combustion system based on discretized coordinate data according to claim 1, characterized in that: Based on the actual compression ratio, the discrete coordinate data and the engine parameters pre-stored in the database are imported into a preset simulation tool to create a three-dimensional simulation model of the combustion system with a compensation volume. The method specifically includes: Calculate the actual compression ratio of the engine based on the three-dimensional solid model of the engine; Obtaining pre-stored engine parameters from the database, including engine bore, stroke, connecting rod length, piston pin offset, compression clearance height, number of injector holes, piston land, and cylinder liner clearance; The discrete coordinate data and the engine parameters stored in the database are imported into the preset simulation tool, and a three-dimensional simulation model of the combustion system is created based on the actual compression ratio and the gap between the piston fire land and the cylinder liner as the compensation volume.

5. The method for establishing a three-dimensional simulation model of a combustion system based on discretized coordinate data according to claim 1, characterized in that: The injector power-on time, engine speed, power-on duration obtained from the ECU, and the injector opening response time and injection duration extension time obtained from the database and provided by the injector manufacturer are input into the preset correction tool to correct the injection time and injection duration obtained from the ECU, and the method specifically includes: Input the injector power-on time, engine speed, power-on duration obtained from the ECU, and the injector opening response time and injection duration extension time obtained from the database and provided by the injector manufacturer into the preset correction tool; The preset correction tool calculates the injection timing based on the power-on time, injector opening response time and engine speed, and corrects the injection timing obtained from the ECU; The preset correction tool calculates the injection duration based on the power-on duration, the injection duration extension time and the engine speed, and corrects the injection duration obtained from the ECU.

6. The method for establishing a three-dimensional simulation model of a combustion system based on discretized coordinate data according to claim 5, characterized in that: The formula for calculating the injection timing based on the power-on timing, injector opening response time and engine speed is: ； in, It is the injection time; is the crankshaft angle at the time of power-on, in degrees / CA; n is the engine speed, in r / min; Injector opening response time, 0.3ms≤ ≤0.4ms.

7. The method for establishing a three-dimensional simulation model of a combustion system based on discretized coordinate data according to claim 5, characterized in that: The calculation formula for calculating the injection duration based on the power-on time, injection duration extension time and engine speed is: ； in, is the injection duration, is the power-on duration, unit: ms; The injection duration is extended, unit: 0.16ms≤ ≤0.6ms.

8. The method for establishing a three-dimensional simulation model of a combustion system based on discretized coordinate data according to claim 1, characterized in that: Input the engine parameters stored in the database and the corrected injection timing, injection duration, injector flow coefficient and injection law curve into the created three-dimensional simulation model of the combustion system, calculate and output the simulation results; The bench measured data and the simulation results are compared and analyzed, and the injector response delay time and the injection duration extension time are adjusted according to the comparative analysis results until the simulation result data is consistent with the bench measured data, and the three-dimensional simulation model of the combustion system is calibrated, and the calibrated three-dimensional simulation model of the combustion system is output. The method specifically includes Obtain engine bench test data at different engine speeds, including cylinder pressure data, hourly fuel consumption, intake volume, EGR rate, and piston temperature measurement data; The initial conditions are obtained through cylinder pressure data, including initial cylinder temperature and pressure, and the cylinder components are calculated through hourly fuel consumption, intake volume, and EGR rate; Setting boundary conditions based on piston temperature measurement data; According to the comparative analysis results of the cylinder pressure and heat release rate curves in the simulation results with the actual test bench data, the injector response delay time and the injection duration extension time are adjusted until the cylinder pressure data and the heat release rate curve are consistent with the actual test bench data. The calibration of the three-dimensional simulation model of the combustion system is completed, and the calibrated three-dimensional simulation model of the combustion system is output.

9. A terminal, characterized in that: include: processor; A memory for storing execution instructions of the processor; The processor is configured to execute the method according to any one of claims 1 to 8.

10. A computer-readable storage medium storing a computer program, characterized in that: When the program is executed by a processor, the method according to any one of claims 1 to 8 is implemented.

Images