Rapid construction method of sustainable aviation fuel combustion reaction mechanism

Abstract

The invention provides a rapid construction method for a sustainable aviation fuel combustion reaction mechanism. The rapid construction method comprises the following steps: S1, establishing a physicochemical property data set of various hydrocarbon substances; s2, establishing a cracking mechanism data set corresponding to various hydrocarbon substances; s3, performing model construction on the agent fuel of the SAF; s4, completing reaction mechanism combination of the proxy fuel; s5, verifying the prediction accuracy of the laminar flame speed according to the constructed SAF combustion mechanism; s6, judging whether the accuracy of the numerical simulation result of the laminar flame velocity meets the requirement or not, and if not, improving the proxy fuel model to increase the types of hydrocarbon substances; s7, after the steps are completed and prediction accuracy verification is completed, an SAF combustion reaction mechanism file suitable for numerical simulation work is obtained, mechanism simplification is conducted, and the calculation efficiency of follow-up simulation is improved. According to the method, the time required for constructing the reaction mechanism can be greatly shortened, the work period can be shortened to be within several hours at the fastest, and the SAF types applicable to the combustion mechanism construction method can be expanded.

Description

Technical Field

[0001] This invention relates to the field of fuel reaction mechanism research, and in particular to a rapid method for constructing a sustainable aviation fuel combustion reaction mechanism. Background Technology

[0002] With dwindling global oil reserves and volatile oil prices, issues such as aviation energy security and economic viability are becoming increasingly prominent. Furthermore, global climate change is placing new demands on the air transport industry, necessitating the search for more environmentally friendly new fuels, such as Sustainable Aviation Fuel (SAF), an alternative fuel that can reduce greenhouse gas emissions throughout its entire lifecycle.

[0003] Faced with the emerging issue of sustainable aviation fuels, there are currently few mature reaction mechanism results available for reference, making it difficult to meet the needs of aero-engines in the pre-research of SAF technology applications. On the other hand, the production sources and process routes of new SAFs are more diversified, resulting in significant differences in component composition between different SAFs, making it difficult to obtain a unified reaction mechanism framework. A reaction mechanism refers to all the elementary reactions that describe a chemical change.

[0004] To meet the need for rapid iterative screening of SAFs in aero-engine combustion simulation, a method is needed to quickly construct the SAF combustion reaction mechanism.

[0005] Existing methods for constructing aviation fuel reaction mechanisms mainly involve the surrogate fuel approach. This approach constructs a surrogate fuel model based on the physical properties (density, viscosity, calorific value, etc.) of real fuels, replacing them with a mixture of several hydrocarbons in a certain proportion. Then, by merging and simplifying the existing mature reaction mechanisms of these hydrocarbons, the reaction mechanism of the surrogate fuel is obtained and used as the combustion reaction mechanism of the real fuel.

[0006] However, due to the different forms of hydrocarbon reaction mechanisms constructed by different researchers and the inconsistent naming methods for intermediate products, many elementary reactions are repetitive but difficult to merge through programming methods, making the merging of reaction mechanisms more complex and difficult to carry out quickly, which is a drawback of this method.

[0007] Furthermore, the lack of a unified framework for proxy fuel models greatly limits the efficiency of this method when dealing with a wide variety of SAFs with different compositions.

[0008] To address the lack of understanding of combustion reaction mechanisms in the early stages of research on sustainable aviation fuels, this study aims to provide better inputs for promoting the engineering applications and numerical simulations of sustainable aviation fuels. The main challenges lie in the following two aspects:

[0009] I. How reaction mechanism construction methods are applicable to different types of SAFs:

[0010] SAF (Superoxide-Rich Fuel) encompasses many types, and due to differences in raw materials and processing techniques, their composition and physicochemical properties vary significantly. For example, HEFA-SPK fuel, obtained through hydrogenation of waste cooking oil, contains approximately 3% cycloalkanes, while CHJ fuel, obtained from lignocellulose through hydrothermal catalytic treatment, can contain up to 12% cycloalkanes.

[0011] Developing reaction mechanisms for each SAF fuel, incorporating fundamental experiments, is time-consuming, hinders engineering applications, and makes rapid screening of SAF fuels difficult through combustion numerical simulations. Therefore, it is necessary to establish a method for constructing combustion reaction mechanisms applicable to different SAFs.

[0012] II. How to achieve rapid construction of reaction mechanisms:

[0013] Existing methods for constructing reaction mechanisms require the integration of experimental data from fuel combustion reactors, resulting in extensive and costly testing. Furthermore, fuels contain multiple components, and the merging and simplification of mechanisms for these components is often complicated by inconsistencies in the naming conventions used by different researchers for intermediate products in their reaction mechanism documents. This necessitates manual modification of the mechanisms, a highly time-consuming process.

[0014] Therefore, it is necessary to optimize and solve the problem of the current time required to construct fuel reaction mechanisms.

[0015] In view of this, the inventors of this application have designed a rapid method for constructing a sustainable aviation fuel combustion reaction mechanism in order to overcome the above-mentioned technical problems. Summary of the Invention

[0016] The technical problem to be solved by the present invention is to overcome the shortcomings of existing reaction mechanism construction methods, such as the inability to be applied to different types of SAFs and the inability to achieve rapid construction of reaction mechanisms, and to provide a rapid construction method for the combustion reaction mechanism of sustainable aviation fuel.

[0017] The present invention solves the above-mentioned technical problems through the following technical solution:

[0018] A rapid method for constructing a sustainable aviation fuel combustion reaction mechanism, characterized in that the rapid method for constructing a sustainable aviation fuel combustion reaction mechanism includes the following steps:

[0019] S1. Establish a dataset of physicochemical properties of various hydrocarbon substances;

[0020] S2. Establish a dataset of cracking mechanisms for various hydrocarbons;

[0021] S3. Model building for SAF's surrogate fuel;

[0022] S4. Complete the reaction mechanism merging of the proxy fuel;

[0023] S5. Verify the accuracy of the prediction of laminar flame velocity based on the constructed SAF combustion mechanism;

[0024] S6. Determine whether the accuracy of the numerical simulation results of laminar flame velocity meets the requirements. If not, improve the surrogate fuel model by adding more types of hydrocarbons.

[0025] S7. After completing the above steps and verifying the accuracy of the prediction, obtain the SAF combustion reaction mechanism file suitable for numerical simulation, and simplify the mechanism to improve the computational efficiency of subsequent simulations.

[0026] According to one embodiment of the present invention, the hydrocarbons in step S1 include straight-chain alkanes, branched-chain alkanes, cycloalkanes, and aromatic hydrocarbons; the physicochemical properties include density, viscosity, calorific value, molecular weight, and hydrogen-to-carbon ratio.

[0027] According to one embodiment of the present invention, step S2 includes: establishing a standardized seven-step cracking mechanism based on hydrocarbon cracking test data or detailed reaction mechanism simulation results, and determining the stoichiometric coefficients of the seven-step cracking mechanism, as shown in the following reaction formulas R1 to R7:

[0028] C m H n →e d (C2H4+λ3C3H6+λ4C4H8)+b d [χC6H6+(1-χ)C7H8]+αH+(2-α)CH3 (R1)

[0029] C m H n +H→H2+γCH4+e a (C2H4+λ3C3H6+λ4C4H8)+b a [χC6H6+(1-χ)C7H8]+βH+(1-β)CH3 (R2)

[0030] C m H n +CH3→CH4+γCH4+e a (C2H4+λ3C3H6+λ4C4H8)+b a [χC6H6+(1-χ)C7H8]+βH+(1-β)CH3(R3)

[0031] C m H n +OH→H2O+γCH4+e a (C2H4+λ3C3H6+λ4C4H8)+ba [χC6H6+(1-χ)C7H8]+βH+(1-β)CH3(R4)

[0032] C m H n +O2→HO2+γCH4+e a (C2H4+λ3C3H6+λ4c4H8)+b a [χC6H6+(1-χ)C7H8]+βH+(1-β)CH3(R5)

[0033] C m H n +HO2→H2O2+γCH4+e a (C2H4+λ3C3H6+λ4C4H8)+b a [χC6H6+(1-χ)C7H8]+βH+(1-β)CH3(R6)

[0034] C m H n +O→OH+γCH4+e a (C2H4+λ3C3H6+λ4C4H8)+b a [χC6H6+(1-χ)C7H8]+βH+(1-β)CH3(R7).

[0035] According to an embodiment of the present invention, step S3 includes:

[0036] S 31 Input the physical properties of sustainable alternative fuels;

[0037] S 32 Multi-objective optimization procedures are used to construct proxy fuel models;

[0038] S 33 Determine the types and proportions of the agency model.

[0039] According to an embodiment of the present invention, step S 32 This includes: constructing a surrogate fuel model using a multi-objective optimization algorithm in Matlab;

[0040] The calculation of the physicochemical properties of the surrogate fuel model includes:

[0041] Molecular weight (g / mol):

[0042] density mol / dm 3 :

[0043] Dynamic viscosity (mPas):

[0044] Hydrogen-to-carbon ratio:

[0045] Lower heating value (MJ / kg):

[0046] Where, x i The value represents the mole fraction of the i-th hydrocarbon. The table below, mix, represents the properties of N hydrocarbons after blending.

[0047] According to one embodiment of the present invention, the multi-objective optimization utilizes the physicochemical properties of several hydrocarbon substances included in the dataset to solve for the mole fraction (x) of each hydrocarbon substance when the objective function reaches its minimum value. i In this case, the hydrocarbon mixture model is the surrogate model of SAF;

[0048] The formula for optimizing the objective function is as follows:

[0049]

[0050]

[0051] Where, p calc p represents the physicochemical properties of the surrogate fuel. exp Indicates the physicochemical properties of SAF fuel.

[0052] N target Indicates the number of types of physicochemical properties predicted;

[0053] E i The difference between the predicted result and the actual fuel for the i-th physicochemical property is represented by the standard deviation of the experimental and predicted values ​​for that property at all temperatures; N data This represents the number of operating points involved in the partial temperature-dependent physicochemical properties, where, except for density and viscosity which are temperature-dependent, the other three properties N... data All are 1.

[0054] According to an embodiment of the present invention, step S4 includes:

[0055] S 41 1. Determine the mechanism documentation for the macromolecular pyrolysis of alternative fuels;

[0056] S 42 Merge the selected cleavage mechanism file and the core mechanism file using a text merging program.

[0057] According to an embodiment of the present invention, step S5 includes:

[0058] S 51 Verification of the accuracy of fuel reaction mechanism;

[0059] S 52 1. Determine whether the laminar flame velocity prediction error meets the requirements; if it does, proceed to step S. 53 If the condition is not met, proceed to step S6.

[0060] S 53 Results of fuel reaction mechanism construction.

[0061] According to one embodiment of the present invention, step S7 uses the direct relationship graph method to simplify the mechanism.

[0062] The positive and progressive effects of this invention are as follows:

[0063] This invention provides a rapid method for constructing the combustion reaction mechanism of sustainable aviation fuels. It establishes a rapid method for constructing the reaction mechanism of sustainable aviation fuels, using fuel physicochemical property parameters that are easier to measure in experiments as input files. It does not require detailed intermediate product data during fuel combustion in basic experiments. The programmed proxy fuel multi-objective optimization algorithm combined with the modular mechanism merging method can greatly shorten the time required to construct the reaction mechanism. The construction cycle of the combustion mechanism of a single SAF can be shortened to within a few hours.

[0064] Meanwhile, the rapid construction method is applicable to SAFs with different process sources and varying physicochemical properties. To address the issue of poor accuracy in predicting the combustion mechanism of some SAFs, the physicochemical property datasets of hydrocarbons and the text sets of pyrolysis mechanisms used in the method can be continuously improved during application, thereby expanding the types of SAFs applicable to the combustion mechanism construction method. Attached Figure Description

[0065] The above and other features, properties and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, in which the same reference numerals always denote the same features, wherein:

[0066] Figure 1 This is a flowchart of the method for rapidly constructing the sustainable aviation fuel combustion reaction mechanism of the present invention.

[0067] Figure 2 This is a schematic diagram of the fuel combustion reaction mechanism in the rapid construction method of sustainable aviation fuel combustion reaction mechanism of the present invention.

[0068] Figure 3 This is a schematic diagram illustrating the definition of laminar flame propagation speed in the rapid construction method for sustainable aviation fuel combustion reaction mechanism of the present invention.

[0069] Figure 4 This is a schematic diagram illustrating the laminar flame ship speed verification in the rapid construction method for sustainable aviation fuel combustion reaction mechanism of the present invention. Detailed Implementation

[0070] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0071] Embodiments of the invention will now be described in detail with reference to the accompanying drawings. Preferred embodiments of the invention will now be described in detail, examples of which are shown in the drawings. Wherever possible, the same reference numerals will be used in all the drawings to denote the same or similar parts.

[0072] Furthermore, although the terminology used in this invention is selected from commonly known and used terms, some terms mentioned in this specification may have been selected by the applicant in his or her judgment, and their detailed meanings are explained in the relevant sections of the description herein.

[0073] Furthermore, the invention should be understood not only through the actual terminology used, but also through the meaning implied by each term.

[0074] like Figures 1 to 4 As shown, this invention discloses a rapid method for constructing a sustainable aviation fuel combustion reaction mechanism, which includes the following steps:

[0075] Step S1: Establish a dataset of physicochemical properties of various hydrocarbon substances 11 (e.g., Figure 1 (As shown).

[0076] Preferably, the hydrocarbons in step S1 include straight-chain alkanes, branched-chain alkanes, cycloalkanes, and aromatic hydrocarbons; the physicochemical properties include density, viscosity, calorific value, molecular weight, and hydrogen-to-carbon ratio. A total of five items are included, and the data are stored in Excel spreadsheet format.

[0077] Here, straight-chain alkanes include n-dodecane and n-tetradecane, branched-chain alkanes include isooctane and isohexadecane, cycloalkanes include propylcyclohexane and decahydronaphthalene, and aromatic hydrocarbons include propenylbenzene.

[0078] Step S2: Establish a dataset of cracking mechanisms for various hydrocarbons 21 (e.g.) Figure 1 (As shown).

[0079] Preferably, step S2 includes: establishing a standardized seven-step cracking mechanism based on hydrocarbon cracking test data or detailed reaction mechanism simulation results, and determining the stoichiometric coefficients of the seven-step cracking mechanism, as shown in the following reaction formulas R1 to R7:

[0080] C m H n →e d (C2H4+λ3C3H6+λ4C4H8)+b d[χC6H6+(1-χ)C7H8]+αH+(2-α)CH3 (R1)

[0081] C m H n +H→H2+γCH4+e a (C2H4+λ3C3H6+λ4C4H8)+b a [χC6H6+(1-χ)C7H8]+βH+(1-β)CH3 (R2)

[0082] C m H n +CH3→CH4+γCH4+e a (C2H4+λ3C3H6+λ4C4H8)+b a [χC6H6+(1-χ)C7H8]+βH+(1-β)CH3(R3)

[0083] C m H n +OH→H2O+γCH4+e a (C2H4+λ3C3H6+λ4C4H8)+b a [χC6H6+(1-χ)C7H8]+βH+(1-β)CH3(R4)

[0084] C m H n +O2→HO2+γCH4+e a (C2H4+λ3C3H6+λ4C4H8)+b a [χC6H6+(1-χ)C7H8]+βH+(1-β)CH3(R5)

[0085] C m H n +HO2→H2O2+γCH4+e a (C2H4+λ3C3H6+λ4C4H8)+b a [χC6H6+(1-χ)C7H8]+βH+(1-β)CH3(R6)

[0086] C m H n +O→OH+γCH4+e a (C2H4+λ3C3H6+λ4C4H8)+b a [xC6H6+(1-x)C7H8]+βH+(1-β)CH3(R7).

[0087] A standardized seven-step cracking mechanism was established for the seven hydrocarbons mentioned above, as shown in R1-R7. Standardization means that the cracking equations for different substances contain the same components, differing only in stoichiometric coefficients. The stoichiometric coefficients for the seven-step cracking mechanism were determined based on experimental data or detailed reaction mechanism simulations of the hydrocarbons. The cracking mechanisms for each of the seven hydrocarbons were pre-stored in a text file and then selected and invoked based on the results of the proxy fuel model construction.

[0088] Step S3: Model the surrogate fuel for SAF (e.g.) Figure 1 (See step 10).

[0089] Preferably, step S3 includes:

[0090] Step S 31 Input the physical properties of sustainable alternative fuels.

[0091] Step S 32 A multi-objective optimization program is used to construct the proxy fuel model.

[0092] Preferably, step S 32 This includes: using the physicochemical properties of SAF (density, viscosity, calorific value, molecular weight, and hydrogen-to-carbon ratio) as input parameters, and constructing a surrogate fuel model using a multi-objective optimization algorithm in Matlab.

[0093] The calculation of the physicochemical properties of the surrogate fuel model includes:

[0094] Molecular weight (g / mol):

[0095] density mol / dm 3 :

[0096] Dynamic viscosity (mPas):

[0097] Hydrogen-to-carbon ratio:

[0098] Lower heating value (MJ / kg):

[0099] Where, x i The value represents the mole fraction of the i-th hydrocarbon. The table below, mix, represents the properties of N hydrocarbons after blending.

[0100] The multi-objective optimization utilizes the physicochemical properties of several hydrocarbons included in the dataset to solve for the mole fraction (x) of each hydrocarbon when the objective function reaches its minimum value. i In this case, the hydrocarbon mixture model is the surrogate model of SAF.

[0101] The formula for optimizing the objective function is as follows:

[0102]

[0103]

[0104] Where, p calc p represents the physicochemical properties of the surrogate fuel. exp Indicates the physicochemical properties of SAF fuel.

[0105] N target Indicates the number of types of physicochemical properties predicted;

[0106] E i The difference between the predicted result and the actual fuel for the i-th physicochemical property is represented by the standard deviation of the experimental and predicted values ​​for that property at all temperatures; N data This represents the number of operating points involved in the partial temperature-dependent physicochemical properties, where, except for density and viscosity which are temperature-dependent, the other three properties N... data All are 1.

[0107] Step S 33 Determine the types and proportions of the agency model.

[0108] Step S4: Complete the reaction mechanism merging of the proxy fuel (e.g.) Figure 1 (See step 20).

[0109] Preferably, step S4 includes:

[0110] Step S 41 1. Determine the mechanism document for the macromolecular pyrolysis of alternative fuels.

[0111] Step S 42 Merge the selected cleavage mechanism file and the core mechanism file using a text merging program.

[0112] During the high-temperature combustion of macromolecular hydrocarbon fuels, by Figure 2 As shown, it can be broken down into two stages: the first stage is the process of pyrolysis or oxidative cracking of macromolecules in fuel into smaller molecules; the second stage is the further oxidation process of the cracking products in the first stage.

[0113] Therefore, based on the composition of the proxy fuel model, the corresponding component pyrolysis mechanism model is selected from the pyrolysis mechanism dataset 21, and the pyrolysis mechanism is merged with the core mechanism through the mechanism text merging procedure 22.

[0114] The pyrolysis mechanism has already been pre-processed in step S2 and can be directly invoked. The core mechanism is based on USC Mech2.0 proposed by the University of Southern California (USC), and is used to characterize the process by which the components generated in the pyrolysis mechanism are further oxidized to generate combustion products. Since the core mechanism contains the intermediate components of all pyrolysis mechanisms, they can be directly combined, which facilitates the construction of fuel reaction mechanisms.

[0115] Step S5: Verify the accuracy of the constructed SAF combustion mechanism for predicting laminar flame velocity (e.g., Figure 1 (See step 30).

[0116] Preferably, step S5 includes:

[0117] Step S 51 Verification of the accuracy of fuel reaction mechanism;

[0118] Step S 52 1. Determine whether the laminar flame velocity prediction error meets the requirements; if it does, proceed to step S. 53 If the condition is not met, proceed to step S6.

[0119] Step S 53 Results of fuel reaction mechanism construction.

[0120] Because the surrogate fuel shares many physicochemical properties with SAF, its reaction mechanism can be considered as the combustion reaction mechanism of SAF itself. The constructed SAF combustion mechanism requires... Figure 1 Step 30 verifies the accuracy of the laminar flame velocity prediction.

[0121] Laminar flame velocity is commonly used to characterize stretching, tempering, and extinguishing phenomena in premixed flames, and is also an important target for verifying chemical reaction models. It is defined as a premixed flame that is planar, non-stretched, and adiabatic (e.g., ...). Figure 3 As shown, the propagation speed relative to the unburned mixture This mainly involves calculating a one-dimensional premixed flame propagation model in ANSYS CHEMKIN software, binding the coordinate system to the flame peak surface, and treating the flame as stationary.

[0122] Due to the large amount of heat released during combustion, the flow rate of the combusted mixture... Much larger The calculated laminar flame velocity of the surrogate fuel is compared with the experimental data of the fuel to determine whether the numerical simulation prediction error meets the requirements.

[0123] Step S6: Determine whether the accuracy of the numerical simulation results of laminar flame velocity meets the requirements. If not, improve the surrogate fuel model by adding more hydrocarbon species (such as...). Figure 1 (See step 40).

[0124] Based on the seven hydrocarbons in the existing dataset, we will further expand the dataset to include hydrocarbons with combustion properties more closely similar to those in SAF, and supplement and update the corresponding physicochemical property datasets (e.g., ...). Figure 1 (as shown) and the cleavage mechanism text set 21 (as shown) Figure 1 (As shown), this addresses the issue of significant differences between the basic combustion properties of current proxy fuel models and SAF.

[0125] Step S7: After completing the above steps and verifying the prediction accuracy, obtain the SAF combustion reaction mechanism file suitable for numerical simulation, and simplify the mechanism to improve the computational efficiency of subsequent simulations.

[0126] Here, step S7 uses the direct relationship diagram method to simplify the mechanism.

[0127] Specifically, taking ethanol-based jet fuel (ATJ) as an example, according to Figure 1 In step 10, a surrogate model of the fuel is obtained using a multi-objective optimization program. The hydrocarbons included are isooctane with a molar fraction of 41.5%, isohexadecane with a molar fraction of 56.4%, and decahydronaphthalene with a molar fraction of 2.1%. The corresponding physicochemical properties are shown in the table below.

[0128]

[0129] The physicochemical properties of the surrogate fuel model are very close to those of real ATJ fuel, so the reaction mechanism of the surrogate model can be used to replace the mechanism of the real fuel.

[0130] Taking ATJ as an example, the above proxy model is applied according to... Figure 1 In step 20, the reaction mechanism is established using a text merging program. The reaction mechanism of ATJ fuel is obtained by merging the selected isooctane, isohexadecane, and decahydronaphthalene cleavage mechanism files with the core mechanism.

[0131] Taking ATJ as an example, the reaction mechanism of the aforementioned ATJ fuel was imported into ANSYS CHEMKIN software. The laminar flame propagation velocity of the fuel was calculated using a premixed laminar flame-speed model, and compared with experimental results measured for ATJ fuel. Figure 4 As shown, it meets the error range requirement that is usually defined as 10%, and the combustion mechanism file can be further applied to CFD combustion numerical simulation work.

[0132] Based on the above process description, the rapid construction method for the combustion reaction mechanism of sustainable aviation fuel of the present invention has the following innovative points:

[0133] I. Standardize the proxy fuel model format for different SAFs:

[0134] The SAF (Salicylic Acid Fuel) is replaced by a mixture of various hydrocarbons. A multi-objective optimization algorithm is used to calculate the proportions based on physicochemical parameters such as fuel density, viscosity, calorific value, molecular weight, and hydrogen-to-carbon ratio. This allows different types of SAF to be replaced by a mixture of hydrocarbons within a fixed range in a specific proportion. Furthermore, the reaction mechanism of the surrogate fuel is constructed based on its hydrocarbon composition, serving as the combustion reaction mechanism for the SAF.

[0135] II. The reaction mechanism of SAF is constructed in a modular manner:

[0136] Referring to existing simplified combustion reaction mechanism construction methods for fuels in the form of "macromolecule pyrolysis + small molecule oxidation," the SAF combustion reaction mechanism is decomposed into two stages: 1. Modular reaction mechanism of pyrolysis of several hydrocarbons in the surrogate fuel model; 2. Core mechanism of small molecule oxidation of pyrolysis products. The pyrolysis mechanism text set constructed in a modular manner is easier to merge through programmatic implementation.

[0137] Third, the applicability and accuracy of this invention can be continuously improved by updating the data files:

[0138] To address the issue of poor accuracy in predicting reaction mechanisms for some fuels, the types of hydrocarbons in the data file can be expanded, and mechanism modules can be added. This provides more options when constructing surrogate fuel models, while maintaining the accuracy of this invention in constructing reaction mechanisms for a wider range of SAFs.

[0139] IV. The reaction mechanism was constructed using computational methods:

[0140] The two main steps in the construction of the SAF reaction mechanism, namely "fuel surrogate model generation" and "module mechanism merging", are both calculated using Matlab programs, saving the time required for manual operation, calculation and modification, and realizing the rapid construction of the reaction mechanism.

[0141] In summary, the present invention provides a rapid method for constructing the combustion reaction mechanism of sustainable aviation fuels. This method establishes a rapid method for constructing the reaction mechanism of sustainable aviation fuels, using fuel physicochemical property parameters that are easier to measure experimentally as input files. It does not require detailed intermediate product data during fuel combustion in basic experiments. The programmed proxy fuel multi-objective optimization algorithm combined with the modular mechanism merging method can greatly shorten the time required to construct the reaction mechanism. The construction cycle of the combustion mechanism of a single SAF can be shortened to within a few hours.

[0142] Meanwhile, the rapid construction method is applicable to SAFs with different process sources and varying physicochemical properties. To address the issue of poor accuracy in predicting the combustion mechanism of some SAFs, the physicochemical property datasets of hydrocarbons and the text sets of pyrolysis mechanisms used in the method can be continuously improved during application, thereby expanding the types of SAFs applicable to the combustion mechanism construction method.

[0143] For those skilled in the art, the above disclosure is merely illustrative and does not constitute a limitation of this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are suggested in this application and therefore remain within the spirit and scope of the exemplary embodiments of this application.

[0144] Furthermore, this application uses specific terms to describe embodiments of the application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic related to at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0145] Similarly, it should be noted that, in order to simplify the description of the embodiments disclosed in this application and thus aid in the understanding of one or more embodiments of the invention, the foregoing description of the embodiments of this application sometimes combines multiple features into a single embodiment, drawing, or description thereof. However, this disclosure method does not imply that the subject matter of this application requires more features than those mentioned in the claims. In fact, the embodiments have fewer features than all the features of the single embodiments disclosed above.

[0146] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A method for rapidly constructing a sustainable aviation fuel combustion reaction mechanism, characterized in that, The rapid construction method for the sustainable aviation fuel combustion reaction mechanism includes the following steps: S1. Establish a dataset of physicochemical properties of various hydrocarbon substances; S2. Establish a dataset of cracking mechanisms for various hydrocarbons; S3. Model the surrogate fuel for SAF; S4. Complete the reaction mechanism merging of the proxy fuel; S5. Verify the accuracy of the prediction of laminar flame velocity based on the constructed SAF combustion mechanism; S6. Determine whether the accuracy of the numerical simulation results of laminar flame velocity meets the requirements. If not, improve the surrogate fuel model by adding more types of hydrocarbons. S7. After completing the above steps and verifying the accuracy of the prediction, obtain the SAF combustion reaction mechanism file suitable for numerical simulation, and simplify the mechanism to improve the computational efficiency of subsequent simulations.

2. The rapid construction method for the sustainable aviation fuel combustion reaction mechanism as described in claim 1, characterized in that, The hydrocarbons in step S1 include straight-chain alkanes, branched-chain alkanes, cycloalkanes, and aromatic hydrocarbons; the physicochemical properties include density, viscosity, calorific value, molecular weight, and hydrogen-to-carbon ratio.

3. The rapid construction method for the sustainable aviation fuel combustion reaction mechanism as described in claim 1, characterized in that, Step S2 includes: establishing a standardized seven-step cracking mechanism based on hydrocarbon cracking test data or detailed reaction mechanism simulation results, and determining the stoichiometric coefficients of the seven-step cracking mechanism, as shown in the following reaction formulas R1 to R7: C m H n →e d (C2H4+λ3C3H6+λ4C4H8)+b d [χC6H6+(1-χ)C7H8]+αH+(2-α)CH3 (R1) C m H n +H→H2+γCH4+e a (C2H4+λ3C3H6+λ4C4H8)+b a [χC6H6+(1-χ)C7H8]+βH+(1-β)CH3 (R2) C m H n +CH3→CH4+γCH4+e a (C2H4+λ3C3H6+λ4C4H8)+b a [χC6H6+(1-χ)C7H8]+βH+(1-β)CH3 (R3) C m H n +OH→H2O+γCH4+e a (C2H4+λ3C3H6+λ4C4H8)+b a [χC6H6+(1-χ)C7H8]+βH+(1-β)CH3 (R4) C m H n +O2→HO2+γCH4+e a (C2H4+λ3C3H6+λ4C4H8)+b a [χC6H6+(1-χ)C7H8]+βH+(1-β)CH3 (R5) C m H n +HO2→H2O2+γCH4+e a (C2H4+λ3C3H6+λ4C4H8)+b a [χC6H6+(1-χ)C7H8]+βH+(1-β)CH3 (R6) C m H n +O→OH+γCH4+e a (C2H4+λ3C3H6+λ4C4H8)+b a [xC6H6+(1-x)C7H8]+βH+(1-β)CH3 (R7).

4. The rapid construction method for the sustainable aviation fuel combustion reaction mechanism as described in claim 1, characterized in that, Step S3 includes: S 31 Input the physical properties of sustainable alternative fuels; S 32 Multi-objective optimization procedures are used to construct proxy fuel models; S 33 Determine the types and proportions of the agency model.

5. The rapid construction method for the sustainable aviation fuel combustion reaction mechanism as described in claim 4, characterized in that, The step S 32 This includes: constructing a surrogate fuel model using a multi-objective optimization algorithm in Matlab; The calculation of the physicochemical properties of the surrogate fuel model includes: Molecular weight (g / mol): density mol / dm 3 : Dynamic viscosity (mPas): Hydrogen-to-carbon ratio: Lower heating value (MJ / kg): Where, x i The value represents the mole fraction of the i-th hydrocarbon. The table below, mix, represents the properties of N hydrocarbons after blending.

6. The rapid construction method for the combustion reaction mechanism of sustainable aviation fuel as described in claim 5, characterized in that, The multi-objective optimization utilizes the physicochemical properties of several hydrocarbons included in the dataset to solve for the mole fraction (x) of each hydrocarbon when the objective function reaches its minimum value. i In this case, the hydrocarbon mixture model is the surrogate model of SAF; The formula for optimizing the objective function is as follows: Where, p calc p represents the physicochemical properties of the surrogate fuel. exp Indicates the physicochemical properties of SAF fuel. N target Indicates the number of types of physicochemical properties predicted; E i The difference between the predicted result and the actual fuel for the i-th physicochemical property is represented by the standard deviation of the experimental and predicted values ​​for that property at all temperatures; N data This represents the number of operating points involved in the partial temperature-dependent physicochemical properties, where, except for density and viscosity which are temperature-dependent, the other three properties N... data All are 1.

7. The rapid construction method for the sustainable aviation fuel combustion reaction mechanism as described in claim 5, characterized in that, Step S4 includes: S 41 1. Determine the mechanism documentation for the macromolecular pyrolysis of alternative fuels; S 42 Merge the selected cleavage mechanism file and the core mechanism file using a text merging program.

8. The rapid construction method for the sustainable aviation fuel combustion reaction mechanism as described in claim 5, characterized in that, Step S5 includes: S 51 Verification of the accuracy of fuel reaction mechanism; S 52 1. Determine whether the laminar flame velocity prediction error meets the requirements; if it does, proceed to step S. 53 If the condition is not met, proceed to step S6. S 53 Results of fuel reaction mechanism construction.

9. The rapid construction method for the sustainable aviation fuel combustion reaction mechanism as described in claim 1, characterized in that, Step S7 simplifies the mechanism using the direct relationship graph method.

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