General diesel fuel construction method and system capable of reproducing engine performance

Abstract

The invention relates to a general diesel fuel construction method and system capable of reproducing engine performance. The method comprises the following step: analyzing the components and content of target diesel oil by adopting comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry and nuclear magnetic resonance technologies. On the basis of n-hexadecane, isohexadecane and 1-methylnaphthalene, a component database is combined, and a model Sur0 is preliminarily constructed. Iterative correction is carried out through deviation functions of three levels of physicochemical characteristics, atomization characteristics and combustion emission characteristics. In each step, the calculation deviation is compared with a preset threshold value, the component proportion is adjusted, optimization models Sur1 and Sur2 are obtained in sequence, and finally a comprehensive alternative fuel model Sur3 capable of accurately simulating target diesel oil is obtained, so that the injection atomization characteristic, the ignition and combustion characteristic, the performance index and various emission characteristics of actual fuel in a cylinder are accurately reproduced; therefore, the method can be used for accurately simulating flow, mixing and combustion characteristics of the diesel engine.

Description

Technical Field

[0001] This application relates to the field of diesel chemical technology, and in particular to a method and system for constructing a universal diesel fuel that can reproduce engine performance. Background Technology

[0002] To date, diesel engines remain the primary power source for various commercial vehicles, construction machinery, agricultural equipment, marine and river vessels, special vehicles, and emergency power supplies. Different models of diesel engines, due to factors such as their operating environments and seasonal variations, use fuels that are all called diesel, but their octane ratings differ significantly.

[0003] Generally, diesel engines used for ground transportation and engineering operations typically use 0#, -10#, or -20# light diesel oil. For special vehicles, to cover a wider operating temperature range, grades such as -35# and -50# are also used. Marine diesel engines used for river and near-shore transport usually use ordinary diesel oil. For low-speed marine engines used in international ocean trade, cheaper heavy fuel oil is typically used, and heavy fuel oil is also graded according to its pour point. Furthermore, diesel engines operating in special environments have specific fuel requirements, which may involve specialized diesel oil, such as mining diesel, high-altitude diesel, or diesel for underwater vessels.

[0004] As is well known, one of the important indicators for characterizing diesel fuel is the cetane number, which reflects the fuel's chemical properties, namely its ignition characteristics, operational reliability, and especially its cold-start reliability. Generally speaking, diesel fuel has a cetane number greater than 40, but the cetane number can be adjusted depending on the specific application.

[0005] The second important indicator for characterizing diesel fuel is its pour point, which is also used by most countries internationally as a designation for diesel fuel. The pour point is actually one of the physical properties of diesel fuel, significantly impacting the storage, transportation, supply, and usage methods of the fuel system. It also has a significant influence on diesel engine injection systems, in-cylinder air-fuel mixture and distribution, ignition and combustion, and pollutant generation. Depending on the application scenario and different power equipment, the pour point range is very wide, from 0℃ to -50℃, and even wider for heavy-duty marine applications.

[0006] Diesel fuels of different grades have significant differences in their detailed composition (carbon group distribution, straight alkanes, branched alkanes, alkenes, cycloalkanes, aromatics, average molecular weight, carbon-hydrogen ratio), physical properties (density, viscosity, surface tension, distillation curve, impurity content, etc.), and chemical properties (ignition characteristics, chemical reaction pathways, soot generation index, types and concentrations of pollutants, etc.). Modern diesel engines strive for extremely high power density and ultra-high thermal efficiency while simultaneously requiring extremely low emissions of harmful substances. Traditional diesel engine development methods based on experience-based design and large-scale testing are insufficient to meet the demands of modern product development. Digital twins, virtual design, sophisticated simulation, and artificial intelligence are necessary to meet the demands of short-cycle, low-cost, and platform-based product development. However, these methods rely on a precise understanding of every process within the entire engine.

[0007] The combustion process in a diesel engine releases the chemical energy of fuel into heat energy, which is then converted into mechanical energy, while simultaneously emitting harmful substances. A deep understanding of the spray, ignition, combustion mechanisms, and emission formation mechanisms of actual diesel fuel is fundamental to achieving these goals. Given the complexity and diversity of the composition of actual diesel fuel, methods have been proposed to characterize it using model fuels with finite components. Generally, these model fuels are required to reproduce some or all of the important properties of actual diesel fuel, such as ignition performance, and / or soot formation characteristics, and / or spray characteristics, and / or combustion characteristics, and / or emission characteristics.

[0008] However, due to the complexity of real diesel fuel composition, researchers often use simpler components to construct model fuels to reproduce certain properties of actual diesel, such as ignition characteristics. For example, early researchers used mixtures of n-heptane and isooctane in different proportions to characterize diesel fuel and developed detailed / simplified kinetic models for numerical simulation of the combustion process. Considering the presence of aromatics in diesel fuel, which are important precursors to soot formation, many scholars have proposed using different proportions of n-heptane, isooctane, and 1-methylnaphthalene as model fuels for diesel. With the development of reaction kinetics, researchers have begun to use components with larger molecular weights, such as n-decane and n-dodecane, as candidate components for diesel model fuels. It is worth noting that these model fuels are mainly used to reproduce the cetane number of diesel, i.e., ignition characteristics, but other physical and chemical properties differ significantly from actual diesel. Therefore, they have significant limitations in diesel engine combustion simulation and performance simulation; simply put, they cannot be used for accurate simulation of spray characteristics, air-fuel mixture, and detailed types of pollutants.

[0009] However, regardless of whether the model fuel construction method is based solely on ignition characteristics or on important physicochemical properties, the properties of the model fuel still deviate somewhat from those of the actual fuel. These deviations arise because some light and heavy components are neglected within the error range, and these components significantly affect spray characteristics, combustion characteristics, and emissions. Therefore, when these model fuels and their kinetic models are used in CFD simulations of actual engines, the calculated injection atomization parameters, ignition and combustion parameters, performance parameters, and emission parameters differ considerably from reality. In other words, the errors in the model fuel construction process are further amplified during combustion. Thus, these results can only be used for qualitative exploration and cannot be used for precise quantitative research.

[0010] Therefore, in order to solve the above problems, this application provides a general diesel fuel construction method and system that can reproduce engine performance. With actual engine performance as the target, it reproduces the spray characteristics (penetration distance, spray angle, average droplet diameter), ignition characteristics (ignition delay), performance indicators (maximum explosion pressure, maximum combustion temperature, median heat release time, indicated thermal efficiency), and emission performance indicators of the target fuel (actual diesel). Summary of the Invention

[0011] Therefore, it is necessary to provide a universal diesel fuel preparation method and system that can reproduce engine performance to address the aforementioned technical problems.

[0012] In a first aspect, this application provides a method for constructing a universal diesel fuel that can reproduce engine performance, comprising the following steps: The components and their contents of the target diesel fuel were obtained by methods including full two-dimensional gas chromatography-time-of-flight mass spectrometry combined with nuclear magnetic resonance techniques of carbon and hydrogen spectrometry. Based on the preset basic components and the preset component database, a first multi-component fuel model Sur0 is initially constructed. The basic components include n-hexadecane, isohexadecane, and 1-methylnaphthalene, and the component database includes several candidate components and their corresponding physicochemical properties. Calculate the physicochemical deviation function S1 between the first multi-component fuel model Sur0 and the target diesel fuel. The physicochemical deviation function S1 includes volatility deviation factor, density deviation factor, viscosity deviation factor, surface tension deviation factor, hydrocarbon ratio deviation factor, and cetane number deviation factor. Based on the physicochemical deviation function S1 and the preset first deviation threshold, the physicochemical deviation factors and the proportions of each candidate component are adjusted when the first deviation threshold is exceeded, until the first deviation threshold is not exceeded, and the second multi-component fuel model Sur1 is obtained. Calculate the atomization characteristic deviation function S2 between the second multi-component fuel model Sur1 and the target diesel fuel. The atomization characteristic deviation function S2 includes a spray cone angle deviation factor, a maximum penetration distance deviation factor, and a droplet average diameter deviation factor. Based on the atomization characteristic deviation function S2 and the preset second deviation threshold, the atomization characteristic deviation factors and the proportion of each candidate component are adjusted when the second deviation threshold is exceeded, until the second deviation threshold is not exceeded, and the third multi-component fuel model Sur2 is obtained. Calculate the combustion emission characteristic deviation function S3 between the third multi-component fuel model Sur2 and the target diesel fuel. The combustion emission characteristic deviation function S3 includes ignition delay deviation factor, maximum cylinder pressure deviation factor, maximum combustion temperature deviation factor, indicated thermal efficiency deviation factor, CO emission deviation factor, HC emission deviation factor, NOx emission deviation factor and soot emission deviation factor. Based on the combustion emission characteristic deviation function S3 and the preset third deviation threshold, the combustion emission characteristic deviation factors and the proportions of each candidate component are adjusted when the third deviation threshold is exceeded, until the third deviation threshold is not exceeded, thus obtaining the final multi-component fuel model Sur3.

[0013] In one embodiment, the candidate components include straight-chain alkanes such as n-heptane, n-decane, n-dodecane, n-hexadecane, n-octadecane, n-eicosane, n-tetracosane, n-triane, and n-hexadecane; isomeric alkanes such as isooctane, isodecane, isododecane, isohexadecane, isooctadecane, and isoeicosane; methylcyclohexane, butylcyclohexane, and decahydronaphthalene; and aromatic hydrocarbons such as toluene, 1-methylnaphthalene, tetrahydronaphthalene, and n-butanecycloalkanes.

[0014] In one embodiment, the formula for calculating the physicochemical deviation function S1 is as follows: , in, As a volatility weighting factor, Density weighting factor Viscosity weighting factor Viscosity weighting factor The carbon-hydrogen ratio weighting factor. This is the weighting factor.

[0015] In one embodiment, the atomization characteristic deviation function S2 is calculated using the following formula: , in, This is the spray cone angle weighting factor. The maximum penetration distance weighting factor. This is the weighting factor for the average droplet diameter.

[0016] In one embodiment, the combustion emission characteristic deviation function S3 is calculated using the following formula: , in, As the ignition delay weighting factor, The maximum cylinder pressure weighting factor. The highest temperature is the weighting factor. To indicate the thermal efficiency weighting factor, As a weighting factor for CO emissions, As a weighting factor for hydrocarbon emissions, NOx emission weighting factor This is a weighting factor for carbon soot emissions.

[0017] In one implementation, the deviation factor for the index to be measured is calculated under various measurement conditions, including: Calculate the absolute value of the difference between the current value of the target diesel fuel's measured index and the current value of the measured index in the current multi-component fuel model; The ratio of the absolute value to the current measured index value of the target diesel fuel is calculated as the deviation factor of the current measured index.

[0018] In one embodiment, the weighting factor in the atomization characteristic deviation function S2 satisfies Generally .

[0019] In one embodiment, the weighting factor in the combustion emission characteristic deviation function S3 satisfies Generally speaking , , , , , , .

[0020] Secondly, this application also provides a universal diesel fuel build system capable of reproducing engine performance, comprising: The acquisition module is used to acquire the components and their contents of the target diesel fuel. The acquisition methods include full two-dimensional gas chromatography-time-of-flight mass spectrometry combined with nuclear magnetic resonance technology of carbon and hydrogen spectrometry. The first calculation module is used to initially construct a first multi-component fuel model Sur0 based on preset basic components and a preset component database. The basic components include n-hexadecane, isohexadecane, and 1-methylnaphthalene. The component database includes several candidate components and their corresponding physicochemical properties. The module also calculates the physicochemical deviation function S1 between the first multi-component fuel model Sur0 and the target diesel fuel. The physicochemical deviation function S1 includes volatility deviation factor, density deviation factor, viscosity deviation factor, surface tension deviation factor, hydrocarbon ratio deviation factor, and cetane number deviation factor. Based on the physicochemical deviation function S1 and a preset first deviation threshold, the module iteratively calculates and adjusts each physicochemical deviation factor and the proportion of each candidate component when the deviation exceeds the first deviation threshold, until the deviation does not exceed the first deviation threshold, thus obtaining a second multi-component fuel model Sur1. The second calculation module is used to calculate the atomization characteristic deviation function S2 between the second multi-component fuel model Sur1 and the target diesel fuel. The atomization characteristic deviation function S2 includes a spray cone angle deviation factor, a maximum penetration distance deviation factor, and a droplet average diameter deviation factor. Based on the atomization characteristic deviation function S2 and a preset second deviation threshold, iterative calculation is performed. When the deviation exceeds the second deviation threshold, the atomization characteristic deviation factors and the proportions of each candidate component are adjusted until the deviation does not exceed the second deviation threshold, thus obtaining the third multi-component fuel model Sur2. The third calculation module is used to calculate the combustion emission characteristic deviation function S3 between the third multi-component fuel model Sur2 and the target diesel fuel. The combustion emission characteristic deviation function S3 includes ignition delay deviation factor, maximum cylinder pressure deviation factor, maximum combustion temperature deviation factor, indicated thermal efficiency deviation factor, CO emission deviation factor, HC emission deviation factor, NOx emission deviation factor, and soot emission deviation factor. Based on the combustion emission characteristic deviation function S3 and a preset third deviation threshold, iterative calculation is performed. When the third deviation threshold is exceeded, the proportions of each combustion emission characteristic deviation factor and each candidate component are adjusted until the third deviation threshold is not exceeded, thus obtaining the final multi-component fuel model Sur3.

[0021] Thirdly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described general diesel fuel construction method that can reproduce engine performance.

[0022] In summary, the universal diesel fuel preparation method and system provided in this application, which can reproduce engine performance, has the following beneficial effects: First, the model fuel constructed in this application can not only reproduce the physicochemical properties of actual fuel, but more importantly, it can accurately reproduce the injection atomization characteristics, ignition and combustion characteristics, performance indicators, and various emission characteristics of actual fuel in the cylinder, thus enabling it to be used for accurate simulation of the flow, mixing, and combustion characteristics of diesel engines.

[0023] Secondly, the model fuel constructed in this application not only includes the main components of diesel fuel, but also small and trace amounts of light and heavy components in diesel fuel. This is the fundamental reason for the difference between the accuracy of model fuel physicochemical property reproduction and the accuracy of actual engine performance reproduction.

[0024] Third, by adjusting the thresholds of the objective functions of physicochemical properties, spray characteristics, combustion performance, and emissions, this application can flexibly change the type, number, proportion, and error of the model fuel components.

[0025] Fourth, the detailed / simplified kinetic mechanism constructed based on the model fuel proposed in this application has the highest accuracy.

[0026] Fifth, the method proposed in this application can also be used in the development of actual diesel products, and can also serve as a method and basis for improving the performance and emissions of diesel engines.

[0027] Sixth, the method proposed in this application can also use other types of fuels, such as gasoline, aviation kerosene, biodiesel, and multi-fuel blends. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a flowchart illustrating a general diesel fuel preparation method that can reproduce engine performance in one embodiment; Figure 2 This is a flowchart illustrating another general diesel fuel preparation method that can reproduce engine performance in one embodiment. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0031] The diesel fuels involved in this application include, but are not limited to, 0#, -10#, -20#, -35#, and -50# diesel fuels for vehicles, as well as fuel oil for inland waterways and heavy oil for ships. Based on the influence of fuel on the engine, the fuel properties analyzed in this application include density, viscosity, surface tension, distillation range, cetane number, hydrocarbon ratio, and aromatics ratio. Based on the influence of fuel on the engine, the engine performance analyzed includes spray cone angle, penetration distance, average droplet diameter, ignition delay time, maximum combustion temperature, maximum cylinder pressure, median exothermic time, indicated thermal efficiency, CO emissions, HC emissions, NOx emissions, and soot emissions.

[0032] In one embodiment, such as Figure 1 As shown, this embodiment provides a method for constructing a universal diesel fuel that can reproduce engine performance, including the following steps: The S100 acquires the components and their contents of the target diesel fuel using a combination of two-dimensional gas chromatography-time-of-flight mass spectrometry and nuclear magnetic resonance (NMR) techniques for carbon and hydrogen spectrometry.

[0033] Specifically, the component composition of the target diesel fuel was analyzed using a two-dimensional gas chromatography-time-of-flight mass spectrometry (GC-TOF-MS). Based on the structural characteristics of hydrocarbons, functional groups were classified into 11 types, and nuclear magnetic resonance (NMR) spectroscopy was used to analyze the functional group composition of the target diesel fuel, thereby obtaining the C / H ratio and aromatics ratio. The fuel properties of the target diesel fuel were measured using a petroleum densitometer, viscometer, vacuum distillation apparatus, and cetane number analyzer. A constant-volume combustion bomb, combined with schlieren technology, was used to measure the spray cone angle and penetration distance of the target diesel fuel at a specific injection pressure. Then, the average droplet diameter was calculated based on the correlation. The main factor affecting spray penetration was the droplet diameter. The density of the bulk fuel, the main factor affecting the spray cone angle, and the main factors affecting the average droplet diameter are fuel viscosity and molecular surface tension. The main factor affecting ignition delay is cetane number. The main factors affecting engine efficiency are cetane number, fuel volatility (distillation range), and hydrocarbon ratio. The main factors determining CO, HC, and NOx emissions are cetane number, fuel volatility (distillation range), and hydrocarbon ratio. The main factors determining soot emissions are cetane number, fuel volatility (distillation range), hydrocarbon ratio, and aromatic content. Under fixed operating conditions on the engine, the engine performance and emission characteristics of the target diesel fuel are measured. Cylinder pressure is measured using a cylinder pressure sensor, and a zero-dimensional calculation program is used to obtain the heat release rate curve, thereby obtaining the ignition delay, median heat release time, maximum combustion temperature, maximum cylinder pressure, and indicated thermal efficiency of the target diesel fuel. An emission analyzer is used to obtain CO, HC, NOx, and soot emissions.

[0034] S200 initially constructs the first multi-component fuel model Sur0 based on preset basic components and preset component database. The basic components include n-hexadecane, isohexadecane, and 1-methylnaphthalene, and the component database includes several candidate components and their corresponding physicochemical properties.

[0035] Specifically, a database of candidate components is established, including straight alkanes such as n-heptane, n-decane, n-dodecane, n-hexadecane, n-octadecane, n-eicosane, n-tetracosane, n-triane, and n-hexadecane; isoalkanes such as isooctane, isodecane, isododecane, isohexadecane, isooctadecane, and isoeicosane; cycloalkanes such as methylcyclohexane, butylcyclohexane, and decahydronaphthalene; and aromatics such as toluene, 1-methylnaphthalene, tetrahydronaphthalene, n-propylbenzene, and n-butylbenzene. A database of physicochemical properties of candidate components is also established, including the density, viscosity, surface tension, carbon-to-hydrogen ratio, boiling point, and hexadecane number of each component.

[0036] In the initial construction of the first multi-component fuel model Sur0 based on basic components and a pre-set component database, the basic three-component model fuel can reproduce the chemical properties of actual diesel fuel, but it is difficult to reproduce the volatility of actual diesel fuel. Therefore, it can match the ignition characteristics of the model fuel in a diesel engine, as well as a certain degree of injection atomization characteristics. After experiments, components 4 to 8 can generally match the injection characteristics, ignition characteristics, combustion characteristics, and emission characteristics, and the established kinetic mechanism can also be used for engine CFD simulation. Since n-hexadecane, isohexadecane, and 1-methylnaphthalene are not only the basic components that define the cetane number of diesel fuel, but also representative substances of the main groups of diesel fuel, the components of the three-component model fuel are n-hexadecane, isohexadecane, and 1-methylnaphthalene. The 4-8 component model fuel is based on n-hexadecane, isohexadecane, and 1-methylnaphthalene, with the addition of other candidate components and changes in their proportions, thereby reproducing the injection characteristics, ignition characteristics, performance indicators, and emission characteristics of actual engines.

[0037] S300 calculates the physicochemical deviation function S1 between the first multi-component fuel model Sur0 and the target diesel fuel. The physicochemical deviation function S1 includes volatility deviation factor, density deviation factor, viscosity deviation factor, surface tension deviation factor, hydrocarbon ratio deviation factor, and cetane number deviation factor.

[0038] S400 is based on the physicochemical deviation function S1 and the preset first deviation threshold for iterative calculation. When the first deviation threshold is exceeded, the proportions of each physicochemical deviation factor and each candidate component are adjusted until the first deviation threshold is not exceeded, thus obtaining the second multi-component fuel model Sur1.

[0039] S500 calculates the atomization characteristic deviation function S2 between the second multi-component fuel model Sur1 and the target diesel fuel. The atomization characteristic deviation function S2 includes the spray cone angle deviation factor, the maximum penetration distance deviation factor, and the droplet average diameter deviation factor.

[0040] Specifically, the volatility modeling of the model fuel is as follows: On the distillation curve of real diesel, the components of the model fuel are arranged from low to high boiling point (T1, T2, ..., Ti) on the ordinate, with their respective proportions being x1, x2, ..., x... i Arrange them on the x-axis, with each component x i The distillation curves of Ti and target diesel form triangular areas Ai, arranged in order from low to high boiling point, forming a progressive approximation model of the multi-component fuel distillation curve. Adjusting the proportion of candidate components of the model fuel can effectively change the shape of the multi-component fuel volatility model. The ratio of the sum of all triangular areas Ai to the area enclosed by the distillation curve and the horizontal axis is called the volatility deviation factor.

[0041] The density modeling of the multi-component fuel is as follows: the densities of the candidate components of the model fuel are ρ1, ρ2, ..., ρ i Their respective proportions are x1, x2, ..., x i Therefore, the density of the model is ρ1x i The density deviation factor is the sum of the difference between the density of real diesel and the density of model fuel and the absolute value of the difference between the density of real diesel and the density of model fuel, which is the ratio of the density of real diesel to the absolute value of the difference between the density of real diesel and the density of model fuel.

[0042] The viscosity modeling of the multi-component fuel is as follows: The carbon-to-hydrogen ratios of the candidate components of the model fuel are respectively... , , ..., Their respective proportions are x1, x2, ..., x i Therefore, the viscosity of the model is The viscosity deviation factor is the ratio of the absolute value of the difference between the actual diesel viscosity and the model fuel viscosity to the actual diesel viscosity.

[0043] The surface tension of the multi-component model fuel is modeled as follows: the surface tensions of the candidate components of the model fuel are ST1, ST2, ..., ST i Their respective proportions are x1, x2, ..., x i Therefore, the surface tension of the model is ST1x i The sum of these factors, the surface tension deviation factor is the ratio of the absolute value of the difference between the surface tension of the actual diesel fuel and the surface tension of the model fuel to the surface tension of the actual diesel fuel.

[0044] The C / H ratio of the multi-component model fuel is modeled as follows: the C / H ratios of the candidate components of the model fuel are (H / C)1, (H / C)2, ..., (H / C)1.i Their respective proportions are x1, x2, ..., x i Therefore, the carbon-hydrogen ratio of the model is (H / C)1x i The sum of these factors, the hydrocarbon ratio deviation factor is the ratio of the absolute value of the difference between the hydrocarbon ratio of the actual diesel fuel and the hydrocarbon ratio of the model fuel to the hydrocarbon ratio of the actual diesel fuel.

[0045] The cetane number modeling of the multi-component model fuel is as follows: the cetane numbers of the candidate components of the model fuel are CN1, CN2, ..., CN2. i Their respective proportions are x1, x2, ..., x i Therefore, the cetane value of the model is CN1x. i The sum of these factors, the cetane number deviation factor, is the ratio of the absolute value of the difference between the cetane number of the actual diesel fuel and the cetane number of the model fuel to the cetane number of the actual diesel fuel.

[0046] Physicochemical property objective function model Solve for the sum of the squares of the density deviation factor, viscosity deviation factor, surface tension deviation factor, C-H ratio deviation factor, saturation deviation factor, cetane number deviation factor, and volatility deviation factor, multiplied by their respective weighting factors. The result approaching the minimum value is the model fuel and its respective proportion. During the calculation process, an initial weighting factor and objective function value are set for calculation. The result of each calculation is compared with the design tolerance. If it exceeds the design error limit, the weighting factor is adjusted. This process is repeated iteratively until a result that meets the requirements is obtained; thus, the candidate components of the model fuel (Sur1) and their respective proportions are obtained.

[0047] S600 is based on the atomization characteristic deviation function S2 and the preset second deviation threshold for iterative calculation. When the second deviation threshold is exceeded, the atomization characteristic deviation factors and the proportion of each candidate component are adjusted until the second deviation threshold is not exceeded, thus obtaining the third multi-component fuel model Sur2.

[0048] S700 calculates the combustion emission characteristic deviation function S3 between the third multi-component fuel model Sur2 and the target diesel fuel. The combustion emission characteristic deviation function S3 includes ignition delay deviation factor, maximum cylinder pressure deviation factor, maximum combustion temperature deviation factor, indicated thermal efficiency deviation factor, CO emission deviation factor, HC emission deviation factor, NOx emission deviation factor, and soot emission deviation factor.

[0049] Specifically, in this invention, the spray characteristic objective function model This is the sum of the squares of the spray cone angle deviation factor, penetration deviation factor, and droplet average diameter deviation factor, multiplied by their respective weighting factors. When If the value exceeds a certain threshold, then the minimum target value of S1 is changed or a new candidate component is selected to obtain a new target value. This led to the acquisition of a new set of model fuels, followed by further spray tests of the model fuels, until... If the value is less than a certain threshold, it becomes a candidate component of the new model fuel (Sur2) and its respective proportion.

[0050] S800 is based on the combustion emission characteristic deviation function S3 and the preset third deviation threshold for iterative calculation. When the third deviation threshold is exceeded, the combustion emission characteristic deviation factors and the proportion of each candidate component are adjusted until the third deviation threshold is not exceeded, thus obtaining the final multi-component fuel model Sur3.

[0051] Specifically, using a high-pressure oil pump (injection pressure 50~200MPa) and a perforated injector (orifice diameter 0.08~0.55mm), the spray cone angles of the target diesel fuel and the model fuel Sur1 were measured on a constant-volume projectile, respectively, as θ and θ'. Sur1 The penetration is respectively L and L Sur1 The average droplet diameters are GDM and GMD, respectively. Sur1 Further, the deviation factor of the spray cone angle was obtained as follows: The penetration deviation factor is ， The deviation factor of the droplet average diameter is .

[0052] On an actual diesel engine, the ignition, combustion, efficiency, and emission characteristics of actual diesel and model fuel (Sur2) were measured at idle speed and at maximum torque speed under 10%, 25%, 50%, 75%, and 100% loads, respectively. The deviation factor for ignition delay was the sum of the absolute values ​​of the differences between the diesel ignition delay and the model fuel ignition delay under each of the above operating conditions and the ratio of the diesel ignition delay. The deviation factor for maximum cylinder pressure was the sum of the absolute values ​​of the differences between the diesel maximum cylinder pressure and the model fuel maximum cylinder pressure under each of the above operating conditions and the ratio of the diesel maximum cylinder pressure. The deviation factor for maximum combustion temperature was the sum of the absolute values ​​of the differences between the diesel maximum combustion temperature and the model fuel maximum combustion temperature under each of the above operating conditions and the ratio of the diesel maximum combustion temperature. The deviation factor for indicated thermal efficiency was the sum of the absolute values ​​of the differences between the diesel indicated thermal efficiency and the model fuel indicated thermal efficiency under each of the above operating conditions and the ratio of the diesel indicated thermal efficiency. The deviation factor for CO emissions is the sum of the ratio of the absolute value of the difference between diesel CO emissions and model fuel CO emissions under each of the above operating conditions to the diesel CO emissions. The deviation factor for HC emissions is the sum of the ratio of the absolute value of the difference between diesel HC emissions and model fuel HC emissions under each of the above operating conditions to the diesel HC emissions. The deviation factor for NOx emissions is the sum of the ratio of the absolute value of the difference between diesel NOx emissions and model fuel NOx emissions under each of the above operating conditions to the diesel NOx emissions. The deviation factor for soot emissions is the sum of the ratio of the absolute value of the difference between diesel soot emissions and model fuel soot emissions under each of the above operating conditions to the diesel soot emissions. Combustion performance and emission objective function model The sum of the squares of the ignition delay deviation factor, maximum cylinder pressure deviation factor, maximum combustion temperature deviation factor, indicated thermal efficiency deviation factor, CO emission deviation factor, HC emission deviation factor, NOx emission deviation factor, and soot emission deviation factor, multiplied by their respective weighting factors; when If it exceeds a certain threshold, then change. Minimal target value or selecting new candidate components to obtain new This led to the acquisition of a new set of model fuels, followed by further spray tests and engine tests on the model fuels, until... The value is less than a certain threshold, thus obtaining the final model fuel Sur3, including its specific components and the proportions of each component; in the above process, adjustments are made. , , The numerical values ​​can change the model's fuel component categories, number of components, component ratios, and errors.

[0053] In a more specific embodiment, such as Figure 2 As shown, a general diesel fuel construction method capable of reproducing engine performance was employed. Two-dimensional gas chromatography-time-of-flight mass spectrometry (GC-TOF) was used to analyze the target diesel fuel. Chromatographic analysis results were analyzed using ChromaTOF software, and the structures of each component were determined based on the MAINLIB, NIST_MASS, NIST_MASS2, NIST_RI, and REPLIB databases, followed by data processing. For isomers, carbon and hydrogen nuclear magnetic resonance (NMR) spectra were used to test and analyze the functional groups of the target diesel fuel, and the spectra were normalized to obtain the carbon functional group distribution of low-grade diesel fuel. Finally, detailed components of the target diesel fuel and the content of each component were obtained, further including the carbon-to-hydrogen ratio, saturation, and aromatic content.

[0054] For the target diesel fuel, the density was measured using the "Determination of Density of Petroleum Products (Density Meter Method)", the kinematic viscosity was measured using the "Determination of Kinematic Viscosity and Calculation of Dynamic Viscosity of Petroleum Products", the surface tension was measured using the "Surface Tension Determination of Surfactants by Pull-up Liquid Film Method", and their distillation range was measured using either vacuum distillation or atmospheric distillation to obtain their respective distillation curves. The cetane number was measured using a cetane number tester according to ASTM D7668 "Standard Test Method for Determination of Cetane Number (DCN) of Diesel Fuel by Constant Volume Combustion Chamber Method - Ignition Delay and Combustion Delay".

[0055] A database of candidate components and their important physicochemical properties was established. The candidate components include straight alkanes such as n-heptane, n-decane, n-dodecane, n-hexadecane, n-octadecane, n-eicosane, n-tetracosane, n-triane, and n-hexadecane; isoalkanes such as isooctane, isodecane, isododecane, isohexadecane, isooctadecane, and isoeicosane; cycloalkanes such as methylcyclohexane, butylcyclohexane, and decahydronaphthalene; and aromatics such as toluene, 1-methylnaphthalene, tetrahydronaphthalene, and n-butane. The properties of each component include density, viscosity, surface tension, carbon-to-hydrogen ratio, boiling point, and cetane number.

[0056] Considering that the definition of diesel ignition characteristics is determined by the ratio between n-hexadecane, isohexadecane, and 1-methylnaphthalene, and that these three components represent the three most important functional groups in diesel—straight-chain alkanes, branched-chain alkanes, and aromatic hydrocarbons, the candidate components for the three-component model fuel are n-hexadecane, isohexadecane, and 1-methylnaphthalene. The 4-8 component model fuel is formed by adding the aforementioned other candidate components to n-hexadecane, isohexadecane, and 1-methylnaphthalene, and changing their respective ratios, thus forming the initial multi-component model fuel Sur0.

[0057] Calculate the volatility deviation between the initial model fuel and the target diesel: On the distillation curve of real diesel, the components of the model fuel are arranged from low to high boiling point (T1, T2, ..., Ti) on the ordinate, with their respective proportions being x1, x2, ..., x... i Arrange them on the x-axis, with each component x i The distillation curves of Ti and the target diesel form triangular areas Ai, arranged in ascending order of boiling point, forming a progressive approximation model for the multi-component fuel distillation curve. Adjusting the proportions of candidate components in the model fuel can change the shape of the multi-component fuel volatility model. The ratio of the sum of all triangular areas Ai to the area (A) enclosed by the distillation curve and the horizontal axis is called the volatility deviation factor, and its calculation formula is: , where n is the score of the i-th group and i is the i-th candidate group.

[0058] Calculate the density deviation between the initial model fuel and the target diesel: the densities of the candidate components of the model fuel are ρ1, ρ2, ..., ρi The proportions of each are x1, x2, ..., x i Therefore, the density of the model fuel is The density deviation factor is the density of the actual diesel fuel. With model fuel density The ratio of the absolute value of the difference to the actual density of diesel oil is calculated using the following formula: .

[0059] Calculate the viscosity deviation between the initial model fuel and the target diesel: the viscosities of the candidate components of the model fuel are respectively , , ..., The proportions of each are x1, x2, ..., x i Therefore, the viscosity of the model fuel is The viscosity deviation factor is the viscosity of the actual diesel oil. With model fuel viscosity The ratio of the absolute value of the difference to the actual diesel viscosity is calculated using the following formula: .

[0060] Calculate the surface tension deviation between the initial model fuel and the target diesel: the surface tensions of the candidate components of the model fuel are ST1, ST2, ..., ST i The proportions of each are x1, x2, ..., x i Therefore, the surface tension of the model fuel is The surface tension deviation factor is the surface tension of the actual diesel fuel. With model fuel surface tension The ratio of the absolute value of the difference to the surface tension of the actual diesel fuel is calculated using the following formula: .

[0061] Calculate the initial carbon-hydrogen ratio deviation between the model fuel and the target diesel: the carbon-hydrogen ratios of the candidate components of the model fuel are H / C1, H / C2, ..., H / C i The proportions of each are x1, x2, ..., x i Therefore, the carbon-to-hydrogen ratio of the model fuel is The hydrocarbon ratio deviation factor is the hydrocarbon ratio of the actual diesel fuel. Compared with the model fuel carbon-hydrogen ratio The formula for calculating the ratio of the absolute value of the difference to the actual hydrocarbon ratio of diesel is as follows: .

[0062] Calculate the cetane number deviation between the initial model fuel and the target diesel: the cetane numbers of the candidate components of the model fuel are CN1, CN2, ..., CN2. i The proportions of each are x1, x2, ..., x iTherefore, the cetane number of the model fuel is... The cetane number deviation factor is the cetane number of the actual diesel fuel. cetane number of model fuel The formula for calculating the ratio of the absolute value of the difference to the actual cetane number of diesel fuel is as follows: .

[0063] Objective model function for calculating physicochemical properties , , Wherein is the volatility weighting factor. Density weighting factor Viscosity weighting factor Viscosity weighting factor The carbon-hydrogen ratio weighting factor. These are weighting factors, and each weighting factor is normalized. .

[0064] In order to solve It allows setting arbitrary initial weighting factors; the results of each calculation are compared with... If the threshold is exceeded, the weighting factor and the proportion of each candidate component are adjusted. This process is repeated iteratively until a result that meets the requirements is obtained; thus, the first-stage optimized model fuel (Sur1) is obtained, including candidate components and their respective proportions.

[0065] In a constant-volume combustion bomb, the gas inside is heated / pressurized to a specific value, typically equivalent to the temperature / pressure before fuel injection in an actual diesel engine, such as a temperature of 800-1000K and a pressure of 30-100 bar. Using high-speed photography, schlieren, and diffuse backlighting, a high-pressure fuel pump and a perforated injector are employed to measure the target diesel fuel and the first-stage optimized model fuel on the constant-volume bomb. The jet atomization characteristics under the same pressure, same nozzle, and same conditions.

[0066] The following steps are taken for post-processing of spray images captured by a high-speed camera: (1) Capture the background image and determine the ratio between the image size and the actual size; (2) Capture the development process of the spray; (3) Process the spray image using an image processing program; (4) Calculate the macroscopic characteristics of the processed spray image, including the target diesel fuel and the model fuel. The spray cone angles (respectively) and ), and maximum penetration distance (respectively) and ), average droplet diameter (respectively) and ).

[0067] The deviation factors for the main parameters of the spray characteristics are calculated. The deviation factor for the spray cone angle is the ratio of the absolute value of the difference between the spray cone angle of the target diesel fuel and the spray cone angle of the model fuel to the spray cone angle of the target diesel fuel. The calculation formula is as follows: The deviation factor for maximum penetration distance is the ratio of the absolute value of the difference between the maximum penetration distance of the target diesel fuel and the maximum penetration distance of the model fuel to the maximum penetration distance of the target diesel fuel. The calculation formula is as follows: The deviation factor for the average droplet diameter is the ratio of the absolute value of the difference between the average droplet diameter of the target diesel fuel and the average droplet diameter of the model fuel to the average droplet diameter of the target diesel fuel. The calculation formula is as follows: .

[0068] Objective model function for calculating spray characteristics , , Where is the spray cone angle weighting factor. The maximum penetration distance weighting factor. The average droplet diameter is used as a weighting factor, and each weighting factor is normalized. .

[0069] In order to solve It allows setting arbitrary initial weight factors and Initial threshold, generally Then calculate ;when If the value exceeds the set threshold, the minimum target value of S1 is changed or a new candidate component is selected (in this selection process, the boiling point of the candidate component is more likely to affect the droplet average diameter deviation factor, and the surface tension of the candidate component has a greater impact on the maximum penetration distance) to obtain a new [target component]. This led to the acquisition of a new set of model fuels, followed by further spray tests of the model fuels, until... The value is less than the set threshold; thus, the second-stage optimized model fuel is obtained, including candidate components and their respective proportions, referred to as... .

[0070] On a diesel engine, a model of target diesel fuel and multi-component diesel fuel was tested. Engine tests are conducted in accordance with relevant national, ministerial, industry, and academic standards. For example, passenger car and commercial vehicle engines are tested using the "Automotive Engine Performance Test Method" (GB / T 18297-2024), marine diesel engines using the "Marine Diesel Engine Bench Test Part 2: Test Methods", and non-road diesel engines using the "Limits and Test Methods for Fuel Consumption Rate of Non-Road Diesel Engines" (20171657-T-604) and "Limits and Measurement Methods for Exhaust Smoke of Non-Road Mobile Diesel Machinery" (GB 36886-2018). The tests measure the torque, cylinder pressure, fuel consumption rate, and various harmful emissions at idle speed and maximum torque speed (vehicle diesel engines) or rated speed (non-road diesel engines and marine diesel engines) at 10%, 25%, 50%, 75%, and 100% load.

[0071] The target diesel fuel was calculated based on engine speed and torque, and fuel consumption rate. The indicated thermal efficiency under the above five operating conditions; based on the measured cylinder pressure and zero-dimensional combustion model, the target diesel fuel and... The ignition delay, maximum combustion temperature, and maximum cylinder pressure are measured under the above five operating conditions.

[0072] Calculate the ignition delay deviation factor for the target diesel and model fuel under the above five operating conditions. The ignition delays are respectively , Where i = 1~5, therefore the deviation factor for ignition delay .

[0073] Calculate the deviation factor for maximum cylinder pressure under the above five operating conditions for both target diesel and model fuel. The maximum cylinder pressures are respectively , Where i = 1~5, therefore the deviation factor of the maximum cylinder pressure .

[0074] Calculate the deviation factor for the highest combustion temperature for both target diesel and model fuel under the five operating conditions mentioned above. The highest combustion temperatures are respectively , Where i = 1~5, therefore the deviation factor for the highest combustion temperature .

[0075] Calculate the deviation factor of indicated thermal efficiency for target diesel and model fuel under the above five operating conditions. The indicated efficiencies are respectively , Where i = 1~5, there is a deviation factor indicating thermal efficiency. .

[0076] Calculate the deviation factor for CO emissions under the five operating conditions mentioned above for both target diesel and model fuel. CO emissions were respectively , Where i = 1~5, therefore the deviation factor for CO emissions .

[0077] Calculate the deviation factor for HC emissions for target diesel and model fuel under the five operating conditions mentioned above. HC emissions were respectively , Where i = 1~5, therefore the deviation factor for HC emissions .

[0078] Calculate the deviation factor for NOx emissions for target diesel and model fuel under the above five operating conditions. NOx emissions were respectively , Where i = 1~5, therefore the deviation factor for NOx emissions .

[0079] Calculate the deviation factor for soot emissions under the above five operating conditions for target diesel and model fuel. The carbon emissions were respectively , Where i = 1~5, therefore the deviation factor for carbon soot emissions .

[0080] Objective model function for calculating combustion and emission characteristics , ,in As the ignition delay weighting factor, The maximum cylinder pressure weighting factor. The highest temperature is the weighting factor. To indicate the thermal efficiency weighting factor, As a weighting factor for CO emissions, As a weighting factor for hydrocarbon emissions, NOx emission weighting factor These are the carbon soot emission weighting factors, and each weighting factor is normalized. .

[0081] In order to solve It allows setting arbitrary initial weight factors and Initial threshold, generally , , , , , , Then calculate ;when When the value exceeds a certain set threshold, change The minimum threshold is recalculated or new candidate components and / or their proportions are selected to obtain new [results]. This leads to a new set of model fuels, including new components and / or new proportions, followed by further spray and engine tests of the model fuels. When the value is less than a certain initial threshold, the third stage or final model fuel is obtained. This includes its specific components and the proportions of each component.

[0082] According to another aspect of this application, this application also provides a universal diesel fuel build system capable of reproducing engine performance, comprising: The acquisition module is used to acquire the components and their contents of the target diesel fuel. The acquisition methods include full two-dimensional gas chromatography-time-of-flight mass spectrometry combined with nuclear magnetic resonance technology of carbon and hydrogen spectrometry.

[0083] The first calculation module is used to initially construct a first multi-component fuel model Sur0 based on preset basic components and a preset component database. The basic components include n-hexadecane, isohexadecane, and 1-methylnaphthalene, and the component database includes several candidate components and their corresponding physicochemical properties. The module also calculates the physicochemical deviation function S1 between the first multi-component fuel model Sur0 and the target diesel fuel. The physicochemical deviation function S1 includes volatility deviation factor, density deviation factor, viscosity deviation factor, surface tension deviation factor, hydrocarbon ratio deviation factor, and cetane number deviation factor. Based on the physicochemical deviation function S1 and a preset first deviation threshold, the module iteratively calculates and adjusts the proportions of each physicochemical deviation factor and each candidate component when the first deviation threshold is exceeded, until the first deviation threshold is not exceeded, thus obtaining a second multi-component fuel model Sur1.

[0084] The second calculation module is used to calculate the atomization characteristic deviation function S2 between the second multi-component fuel model Sur1 and the target diesel fuel. The atomization characteristic deviation function S2 includes the spray cone angle deviation factor, the maximum penetration distance deviation factor, and the droplet average diameter deviation factor. Based on the atomization characteristic deviation function S2 and the preset second deviation threshold, iterative calculation is performed. When the second deviation threshold is exceeded, the atomization characteristic deviation factors and the proportion of each candidate component are adjusted until the second deviation threshold is not exceeded, so as to obtain the third multi-component fuel model Sur2.

[0085] The third calculation module is used to calculate the combustion emission characteristic deviation function S3 between the third multi-component fuel model Sur2 and the target diesel fuel. The combustion emission characteristic deviation function S3 includes ignition delay deviation factor, maximum cylinder pressure deviation factor, maximum combustion temperature deviation factor, indicated thermal efficiency deviation factor, CO emission deviation factor, HC emission deviation factor, NOx emission deviation factor, and soot emission deviation factor. Based on the combustion emission characteristic deviation function S3 and the preset third deviation threshold, iterative calculation is performed. When the third deviation threshold is exceeded, the proportions of each combustion emission characteristic deviation factor and each candidate component are adjusted until the third deviation threshold is not exceeded, thus obtaining the final multi-component fuel model Sur3.

[0086] Based on the same inventive concept, this application also provides a universal diesel fuel construction system that can reproduce engine performance, which is a method for constructing universal diesel fuel that can reproduce engine performance. The solution provided by this system is similar to the solution described in the above method. Therefore, the specific limitations of one or more embodiments of the universal diesel fuel construction system that can reproduce engine performance provided below can be found in the limitations of the universal diesel fuel construction method that can reproduce engine performance described above, and will not be repeated here.

[0087] The modules or units in the aforementioned universal diesel fuel construction system capable of reproducing engine performance can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can invoke and execute the operations corresponding to each module.

[0088] In one embodiment, this application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps described above in the embodiment of the general diesel fuel construction method that can reproduce engine performance.

[0089] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0090] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0091] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0092] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for constructing a universal diesel fuel capable of reproducing engine performance, characterized in that, Including the following steps: The components and their contents of the target diesel fuel were obtained by methods including full two-dimensional gas chromatography-time-of-flight mass spectrometry combined with nuclear magnetic resonance techniques of carbon and hydrogen spectrometry. Based on the preset basic components and the preset component database, a first multi-component fuel model Sur0 is initially constructed. The basic components include n-hexadecane, isohexadecane, and 1-methylnaphthalene, and the component database includes several candidate components and their corresponding physicochemical properties. Calculate the physicochemical deviation function S1 between the first multi-component fuel model Sur0 and the target diesel fuel. The physicochemical deviation function S1 includes volatility deviation factor, density deviation factor, viscosity deviation factor, surface tension deviation factor, hydrocarbon ratio deviation factor, and cetane number deviation factor. Based on the physicochemical deviation function S1 and the preset first deviation threshold, the physicochemical deviation factors and the proportions of each candidate component are adjusted when the first deviation threshold is exceeded, until the first deviation threshold is not exceeded, and the second multi-component fuel model Sur1 is obtained. Calculate the atomization characteristic deviation function S2 between the second multi-component fuel model Sur1 and the target diesel fuel. The atomization characteristic deviation function S2 includes a spray cone angle deviation factor, a maximum penetration distance deviation factor, and a droplet average diameter deviation factor. Based on the atomization characteristic deviation function S2 and the preset second deviation threshold, the atomization characteristic deviation factors and the proportion of each candidate component are adjusted when the second deviation threshold is exceeded, until the second deviation threshold is not exceeded, and the third multi-component fuel model Sur2 is obtained. Calculate the combustion emission characteristic deviation function S3 between the third multi-component fuel model Sur2 and the target diesel fuel. The combustion emission characteristic deviation function S3 includes ignition delay deviation factor, maximum cylinder pressure deviation factor, maximum combustion temperature deviation factor, indicated thermal efficiency deviation factor, CO emission deviation factor, HC emission deviation factor, NOx emission deviation factor and soot emission deviation factor. Based on the combustion emission characteristic deviation function S3 and the preset third deviation threshold, the combustion emission characteristic deviation factors and the proportions of each candidate component are adjusted when the third deviation threshold is exceeded, until the third deviation threshold is not exceeded, thus obtaining the final multi-component fuel model Sur3.

2. The construction method according to claim 1, characterized in that, The candidate components include straight-chain alkanes such as n-heptane, n-decane, n-dodecane, n-hexadecane, n-octadecane, n-eicosane, n-tetracosane, n-triane, and n-hexadecane; isomeric alkanes such as isooctane, isodecane, isododecane, isohexadecane, isooctadecane, and isoeicosane; methylcyclohexane, butylcyclohexane, and decahydronaphthalene; and aromatic hydrocarbons such as toluene, 1-methylnaphthalene, tetrahydronaphthalene, and n-butanecycloalkanes.

3. The construction method according to claim 1, characterized in that, The formula for calculating the physicochemical deviation function S1 is as follows: ， in, As a volatility weighting factor, Density weighting factor Viscosity weighting factor Viscosity weighting factor The carbon-hydrogen ratio weighting factor. This is the weighting factor.

4. The construction method according to claim 1, characterized in that, The formula for calculating the atomization characteristic deviation function S2S2 is as follows: ， in, This is the spray cone angle weighting factor. The maximum penetration distance weighting factor. This is the weighting factor for the average droplet diameter.

5. The construction method according to claim 1, characterized in that, The formula for calculating the combustion emission characteristic deviation function S3 is as follows: ， in, As the ignition delay weighting factor, The maximum cylinder pressure weighting factor. The highest temperature is the weighting factor. To indicate the thermal efficiency weighting factor, As a weighting factor for CO emissions, As a weighting factor for hydrocarbon emissions, NOx emission weighting factor This is a weighting factor for carbon soot emissions.

6. The construction method according to claim 1, characterized in that, The deviation factor for the measured index is calculated under various measurement conditions, including: Calculate the absolute value of the difference between the current value of the target diesel fuel's measured index and the current value of the measured index in the current multi-component fuel model; The ratio of the absolute value to the current measured index value of the target diesel fuel is calculated as the deviation factor of the current measured index.

7. The construction method according to claim 4, characterized in that, The weighting factor in the atomization characteristic deviation function S2 satisfies Generally .

8. The construction method according to claim 5, characterized in that, The weighting factor in the combustion emission characteristic deviation function S3 satisfies Generally speaking , , , , , , .

9. A universal diesel fuel build system capable of reproducing engine performance, characterized in that, include: The acquisition module is used to acquire the components and their contents of the target diesel fuel. The acquisition methods include full two-dimensional gas chromatography-time-of-flight mass spectrometry combined with nuclear magnetic resonance technology of carbon and hydrogen spectrometry. The first calculation module is used to initially construct a first multi-component fuel model Sur0 based on preset basic components and a preset component database. The basic components include n-hexadecane, isohexadecane, and 1-methylnaphthalene. The component database includes several candidate components and their corresponding physicochemical properties. The module also calculates the physicochemical deviation function S1 between the first multi-component fuel model Sur0 and the target diesel fuel. The physicochemical deviation function S1 includes volatility deviation factor, density deviation factor, viscosity deviation factor, surface tension deviation factor, hydrocarbon ratio deviation factor, and cetane number deviation factor. Based on the physicochemical deviation function S1 and a preset first deviation threshold, the module iteratively calculates and adjusts each physicochemical deviation factor and the proportion of each candidate component when the deviation exceeds the first deviation threshold, until the deviation does not exceed the first deviation threshold, thus obtaining a second multi-component fuel model Sur1. The second calculation module is used to calculate the atomization characteristic deviation function S2 between the second multi-component fuel model Sur1 and the target diesel fuel. The atomization characteristic deviation function S2 includes a spray cone angle deviation factor, a maximum penetration distance deviation factor, and a droplet average diameter deviation factor. Based on the atomization characteristic deviation function S2 and a preset second deviation threshold, iterative calculation is performed. When the deviation exceeds the second deviation threshold, the atomization characteristic deviation factors and the proportions of each candidate component are adjusted until the deviation does not exceed the second deviation threshold, thus obtaining the third multi-component fuel model Sur2. The third calculation module is used to calculate the combustion emission characteristic deviation function S3 between the third multi-component fuel model Sur2 and the target diesel fuel. The combustion emission characteristic deviation function S3 includes ignition delay deviation factor, maximum cylinder pressure deviation factor, maximum combustion temperature deviation factor, indicated thermal efficiency deviation factor, CO emission deviation factor, HC emission deviation factor, NOx emission deviation factor, and soot emission deviation factor. Based on the combustion emission characteristic deviation function S3 and a preset third deviation threshold, iterative calculation is performed. When the third deviation threshold is exceeded, the proportions of each combustion emission characteristic deviation factor and each candidate component are adjusted until the third deviation threshold is not exceeded, thus obtaining the final multi-component fuel model Sur3.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 8.

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