Prediction method, device and equipment for turbulent combustion characteristics and medium

Abstract

The invention discloses a turbulent combustion characteristic prediction method, device, equipment and medium, and aims to rapidly and accurately predict hydrocarbon fuel turbulent combustion characteristics, the turbulent combustion characteristic prediction method comprises the following steps: constructing a three-step reaction mechanism, the three-step reaction mechanism comprises a first reaction mechanism using hydrocarbon fuel and oxygen as reaction fuels; a second reaction mechanism using carbon monoxide and oxygen as reaction fuels; a third reaction mechanism in which hydrogen and oxygen are used as reaction fuels; a three-step reaction mechanism is carried out by taking hydrocarbon fuel as fuel through a zero-dimensional isobaric flame model, the highest temperature during complete combustion of the hydrocarbon fuel is determined as adiabatic equilibrium temperature, and the maximum value point of the temperature change rate in the combustion process of the hydrocarbon fuel is determined as ignition delay; the laminar flame velocity is determined according to the index relationship between the reaction pressure and the laminar flame velocity through a three-step reaction mechanism by taking hydrocarbon fuel as fuel through a one-dimensional isobaric flame model.

Description

Technical Field

[0001] The present invention relates to the field of prediction of combustion characteristics, and in particular to a method, device, equipment and medium for predicting turbulent combustion characteristics. Background Art

[0002] Common fuels in industrial power plants include natural gas, gasoline, diesel, kerosene, etc. As the number of carbon atoms increases, the number of components in the detailed mechanism of its oxidation reaction increases from dozens to thousands, and the number of elementary reactions gradually increases from more than 300 steps to thousands or even tens of thousands. In order to accurately predict the unsteady turbulent combustion characteristics of hydrocarbon fuels, the most direct method is to integrate the detailed mechanism into the fluid equation, but this will lead to a sharp increase in calculation time, and the calculation cost of combustion will far exceed that of flow.

[0003] Therefore, how to quickly and accurately predict the turbulent combustion characteristics of hydrocarbon fuels has become a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0004] The object of the present invention is to provide a method, device, equipment and medium for predicting turbulent combustion characteristics, so as to quickly and accurately predict the turbulent combustion characteristics of hydrocarbon fuels.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention first provides a method for predicting turbulent combustion characteristics, comprising:

[0007] A three-step reaction mechanism is constructed by using hydrocarbon fuel, oxygen, carbon monoxide, carbon dioxide, oxygen and water as a component system, wherein the three-step reaction mechanism includes a first reaction mechanism using the hydrocarbon fuel and the oxygen as reaction fuels, and the products of the first reaction mechanism are carbon monoxide and hydrogen; a second reaction mechanism using the carbon monoxide and the oxygen as reaction fuels, and the product of the second reaction mechanism is carbon dioxide; a third reaction mechanism using the hydrogen and the oxygen as reaction fuels, and the product of the third reaction mechanism is water;

[0008] Using a zero-dimensional isobaric flame model, a hydrocarbon fuel is used as fuel to carry out a three-step reaction mechanism, and the maximum temperature when the hydrocarbon fuel is completely burned is determined as the adiabatic equilibrium temperature, and the maximum value point of the temperature change rate during the combustion of the hydrocarbon fuel is determined as the ignition delay;

[0009] By using a one-dimensional isobaric flame model, a three-step reaction mechanism is performed using hydrocarbon fuel as fuel, the reaction pressure is determined, and the laminar flame speed is determined based on the exponential relationship between the reaction pressure and the laminar flame speed;

[0010] Among them, the adiabatic equilibrium temperature, the ignition delay and the laminar flame speed are the turbulent combustion characteristics.

[0011] In an optional embodiment of the present application, the three-step reaction mechanism is represented by the following method:

[0012] R1:

[0013] R2:

[0014] R3:

[0015] Among them, R1 represents the first reaction mechanism; R2 represents the second reaction mechanism; R3 represents the third reaction mechanism.

[0016] In an optional embodiment of the present application, the one-dimensional isobaric flame model is used to carry out a three-step reaction mechanism with hydrocarbon fuel as fuel, determine the reaction pressure, and determine the laminar flame speed according to the exponential relationship between the reaction pressure and the laminar flame speed, including:

[0017] Introducing a third body effect into the first reaction mechanism of the three-step reaction mechanism;

[0018] The reaction pressure is determined by a one-dimensional isobaric flame model, using hydrocarbon fuel as fuel and a three-step reaction mechanism introducing a third body effect, and the laminar flame speed is determined according to the exponential relationship between the reaction pressure and the laminar flame speed.

[0019] In an optional embodiment of the present application, the first reaction mechanism of introducing the third body effect is represented by the following method:

[0020] R1:

[0021] Wherein, M represents a catalyst.

[0022] In an optional embodiment of the present application, the exponential relationship between the reaction pressure and the laminar flame speed is expressed by the following formula:

[0023]

[0024] Among them, S L is the laminar flame speed; P is the reaction pressure; n is the reaction order; λ is the thermal conductivity; C P is the isobaric specific heat capacity; E a is the activation energy; T b is the burnt gas temperature; R is the gas constant.

[0025] In an optional implementation manner of the present application, the ignition delay is expressed by the following formula:

[0026]

[0027] Wherein, τ is the ignition delay; P is the reaction pressure; n is the reaction order; n1 is the fuel reaction order; E a is the activation energy; is the equivalence ratio; T is the temperature; R is the gas constant.

[0028] In an optional implementation of the present application, it also includes:

[0029] Determine the comparative turbulent combustion characteristics based on detailed and skeleton mechanisms;

[0030] Determine whether the difference between the control turbulent combustion characteristics and the turbulent combustion characteristics is greater than a preset threshold; if the difference between the control turbulent combustion characteristics and the turbulent combustion characteristics is greater than the preset threshold, adjust the third body effect, reaction order and activation energy of the three-step reaction mechanism until the difference between the control turbulent combustion characteristics and the turbulent combustion characteristics is less than or equal to the preset threshold.

[0031] Compared with the prior art, the method for predicting turbulent combustion characteristics provided by the present invention constructs a three-step reaction mechanism by using hydrocarbon fuel, oxygen, carbon monoxide, carbon dioxide, oxygen and water as a component system, so that hydrogen, an intermediate product produced by the reaction of hydrocarbon fuel and oxygen, is introduced into the three-step reaction mechanism, thereby greatly improving the accuracy of the adiabatic equilibrium temperature while maintaining a relatively low cost.

[0032] Furthermore, in the embodiment of the present application, a third system parameter of the catalyst is introduced into the first reaction mechanism in which the hydrocarbon fuel and the oxygen are used as reaction fuels at the same time, so as to meet the laminar flame speed in both air and pure oxygen environments.

[0033] Furthermore, the turbulent combustion characteristics provided in the embodiments of the present application can determine the distribution of the ignition delay with pressure and temperature, so that the ignition delay can be determined in combination with the reaction order, and the accuracy of the ignition delay can be guaranteed while satisfying the laminar flame speed.

[0034] The present invention also provides a device for predicting turbulent combustion characteristics, comprising:

[0035] A mechanism construction unit, for constructing a three-step reaction mechanism using hydrocarbon fuel, oxygen, carbon monoxide, carbon dioxide, oxygen and water as a component system, wherein the three-step reaction mechanism includes a first reaction mechanism using the hydrocarbon fuel and the oxygen as reaction fuels, and the products of the first reaction mechanism are carbon monoxide and hydrogen; a second reaction mechanism using the carbon monoxide and the oxygen as reaction fuels, and the product of the second reaction mechanism is carbon dioxide; a third reaction mechanism using the hydrogen and the oxygen as reaction fuels, and the product of the third reaction mechanism is water;

[0036] The first reaction unit is used to perform a three-step reaction mechanism using a zero-dimensional isobaric flame model with a hydrocarbon fuel as fuel, determine the maximum temperature when the hydrocarbon fuel is completely burned as the adiabatic equilibrium temperature, and determine the maximum value point of the temperature change rate during the combustion of the hydrocarbon fuel as the ignition delay;

[0037] The second reaction unit is used to determine the reaction pressure by a one-dimensional isobaric flame model and a three-step reaction mechanism using hydrocarbon fuel as fuel, and to determine the laminar flame speed according to the exponential relationship between the reaction pressure and the laminar flame speed;

[0038] Among them, the adiabatic equilibrium temperature, the ignition delay and the laminar flame speed are the turbulent combustion characteristics.

[0039] Compared with the prior art, the beneficial effects of the device for predicting turbulent combustion characteristics provided by the present invention are the same as the beneficial effects of the method for predicting turbulent combustion characteristics described in the above technical solution, which will not be elaborated here.

[0040] The present invention also provides an electronic device, comprising:

[0041] processor;

[0042] a memory for storing instructions executable by the processor;

[0043] The processor is used to execute the above-mentioned method for predicting turbulent combustion characteristics by running the instructions in the memory.

[0044] Compared with the prior art, the beneficial effects of the electronic device provided by the present invention are the same as the beneficial effects of the method for predicting turbulent combustion characteristics described in the above technical solution, and will not be elaborated here.

[0045] The present invention also provides a computer storage medium, in which instructions are stored. When the instructions are executed, the above-mentioned method for predicting turbulent combustion characteristics is implemented.

[0046] Compared with the prior art, the beneficial effects of the computer storage medium provided by the present invention are the same as the beneficial effects of the method for predicting turbulent combustion characteristics described in the above technical solution, and will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0048] Figure 1 A flow chart of a method for predicting turbulent combustion characteristics provided in an embodiment of the present application;

[0049] Figure 2 A structural diagram of a device for predicting turbulent combustion characteristics provided in an embodiment of the present application;

[0050] Figure 3 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0051] In order to clearly describe the technical solutions of the embodiments of the present invention, in the embodiments of the present invention, words such as "first" and "second" are used to distinguish the same items or similar items with basically the same functions and effects. For example, the first threshold and the second threshold are only used to distinguish different thresholds, and their order is not limited. Those skilled in the art can understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit them to be different.

[0052] It should be noted that, in the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0053] In the present invention, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, the combination of a and b, the combination of a and c, the combination of b and c, or the combination of a, b and c, where a, b, c can be single or multiple.

[0054] Common fuels in industrial power plants include natural gas, gasoline, diesel, kerosene, etc. As the number of carbon atoms increases, the number of components in the detailed mechanism of its oxidation reaction increases from dozens to thousands, and the number of elementary reactions gradually increases from more than 300 steps to thousands or even tens of thousands. In order to accurately predict the unsteady turbulent combustion characteristics of hydrocarbon fuels, the most direct method is to integrate the detailed mechanism into the fluid equation, but this will lead to a sharp increase in calculation time, and the calculation cost of combustion will far exceed that of flow, so it is necessary to simplify combustion.

[0055] One simplified method is to develop a turbulent combustion model, the Eddy Dissipation Concept (EDC) and the Partially Stirred Reaction (PaSR) developed on the basis of the Eddy Dissipation Model (EDM). The EDC model assumes that combustion occurs in the turbulent small-scale structure in an isobaric form. The model can be combined with detailed mechanisms and reduce integral rigidity and computational costs in the form of In Situ Adaptive Tabulation (ISAT). In order to significantly reduce computational costs when combining detailed mechanisms, the Laminar Flamelet Method (LFM) considers turbulent flames to be an ensemble of laminar flame surfaces (generally generated by one-dimensional counter-flow flames), and the thermochemical state depends on the mixture fraction, scalar dissipation, and progress variables, where scalar dissipation is equivalent to strain rate. Different from reduced-order models such as LFM, the probability density function transport equation model (TPDF) is a strictly derived single-point statistical model. The probability density here can be considered as the fraction of time experienced by the fluid at various locations in the phase space (temperature, velocity or velocity gradient and N-dimensional components). Its high-dimensional properties determine the need to use Monte Carlo particles to characterize the random field. Its computational memory and cost are too high, and it is often necessary to combine ISAT to reduce memory and computation.

[0056] Although the table building method can significantly reduce the computational cost when combined with detailed mechanisms, it still faces many challenges in engineering applications. First, there are generally multiple inlets in industrial power plants. Considering the different inlet mixing ratios, temperatures and pressures, as well as the influence of heat loss and exhaust gas, this results in more than one passive scalar required to describe the mixing, which greatly increases the memory required and the difficulty of table building. Secondly, there are various types of combustion in industrial power plants, including premixed and non-premixed, self-ignition and non-self-ignition, laminar and turbulent, which makes it difficult to select a suitable one-dimensional laminar flame to build a table. Finally, the table built using the EDC model for steady-state combustion of a specific power plant is often not universal under other configurations or operating conditions.

[0057] Another way to simplify the reaction mechanism is to directly simplify the reaction mechanism. Compared with the detailed mechanism, this method has the following advantages: First, in industrial applications, thermal efficiency and emission issues are often the most concerned, and a large number of intermediate products are not of interest. Therefore, a large number of elementary reactions in the detailed mechanism appear to be "redundant"; second, the simplified mechanism only cares about a few intermediate products and the number of reactions is small, so the required memory and computing costs are much smaller, which is convenient for engineering applications; third, the detailed mechanism can accurately predict flame characteristics such as adiabatic equilibrium temperature, laminar flame speed and ignition delay within a very wide working range; fifth, the simplified mechanism can also be easily combined with various combustion models.

[0058] The existing one-step and two-step total package mechanisms of hydrocarbon fuels are widely used in the engineering field, but both have the problem of too high adiabatic equilibrium temperature and laminar flame speed in a pure oxygen environment, which limits their application under conditions with relatively low nitrogen and oxygen content.

[0059] The existing 22-step reaction mechanism has added a variety of intermediates, but there are still problems with the laminar flame speed being too high in a pure oxygen environment and the relatively high computational cost. Moreover, it has not been compared with the ignition delay obtained from experiments and detailed mechanical calculations. Therefore, its application in ignition problems needs to be questioned.

[0060] The existing four-step reaction mechanism of methane to butane takes into account the two intermediate components, CO and H2, but there is a negative reaction order, which will cause great numerical instability in the calculation.

[0061] The existing two-step mechanism of kerosene adds an equivalence ratio correction function before the pre-exponential coefficient to improve the distribution of laminar flame speed in equivalence ratio, but the calculation of a large number of hyperbolic tangent functions will greatly increase the computational cost, and there is also numerical instability caused by reaction rate jump in actual calculations. The skeleton reaction mechanism obtained through sensitivity analysis has been greatly simplified compared to the detailed mechanism, but there are still 58 steps for methane and thousands of steps for decane, which is still too expensive in engineering calculations. In addition, most researchers use the assumption that the Lewis number is 1 when calculating the laminar flame speed of the simplified mechanism, which will have a large deviation in the shear layer or the flow field with strong compressibility.

[0062] In view of the above technical status, the present application proposes a method, device, equipment and medium for predicting turbulent combustion characteristics to quickly and accurately predict the turbulent combustion characteristics of hydrocarbon fuels, which are described in detail one by one in the following embodiments.

[0063] The embodiment of the present application first provides a method for predicting turbulent combustion characteristics, which reduces the reaction mechanism of hydrocarbon fuels to three steps, greatly reducing the calculation cost of turbulent combustion.

[0064] Please refer to Figure 1 , Figure 1A flow chart of a method for predicting turbulent combustion characteristics provided in an embodiment of the present application.

[0065] like Figure 1 As shown, the prediction method of turbulent combustion characteristics includes the following S101 to S103:

[0066] S101, a three-step reaction mechanism is constructed using hydrocarbon fuel, oxygen, carbon monoxide, carbon dioxide, oxygen and water as a component system, wherein the three-step reaction mechanism includes a first reaction mechanism using the hydrocarbon fuel and the oxygen as reaction fuels, and the products of the first reaction mechanism are carbon monoxide and hydrogen; a second reaction mechanism using the carbon monoxide and the oxygen as reaction fuels, and the product of the second reaction mechanism is carbon dioxide; and a third reaction mechanism using the hydrogen and the oxygen as reaction fuels, and the product of the third reaction mechanism is water.

[0067] Previous simplified mechanisms often make assumptions about transport and thermodynamic properties that the Lewis number Le is 1 and the Prandtl number Pr is a constant. This assumption will affect the laminar flame speed and flame structure. In order to overcome the impact of this assumption on the basic properties of the flame, this application uses transport coefficients based on kinetic theory and fitted thermodynamic parameters that vary with temperature. Taking into account the actual transport coefficients and thermodynamic parameters, the basic properties of hydrocarbon fuel flames, including adiabatic equilibrium temperature, laminar flame speed and ignition delay, are calculated based on the zero-dimensional isobaric adiabatic flame model and the one-dimensional laminar flame model. The importance of the three basic properties in industrial power plants is ranked as adiabatic equilibrium temperature> laminar flame speed> ignition delay.

[0068] Among the basic properties of hydrocarbon fuel flames, the most concerned one in industrial power plants is the adiabatic equilibrium temperature, which is defined as the temperature at zero-dimensional isobaric adiabatic combustion, at which the Gibbs free energy is at its lowest equilibrium state, and the component distribution of each elementary reaction reaches the chemical equilibrium constant, which is expressed by the following formula (1):

[0069]

[0070] in, and are the concentrations of products and reactants respectively; ΔG mol (T) is the difference in Gibbs free energy between reactants and products at temperature T; R is the gas constant; K is the chemical equilibrium constant.

[0071] Based on the above formula (1), it can be seen that the adiabatic equilibrium temperature has nothing to do with the reaction path and the reaction speed. Therefore, in order to ensure the accuracy of the adiabatic equilibrium temperature, it is necessary to consider adding intermediates.

[0072] In order to ensure accuracy and minimize the number of components, the important intermediate product hydrogen is additionally considered on the basis of the two-step reaction system, thus forming a component system consisting of hydrocarbon fuel, oxygen, carbon monoxide, carbon dioxide, hydrogen and water.

[0073] Specifically, the three-step reaction mechanism is represented by the following method:

[0074] R1:

[0075] R2:

[0076] R3:

[0077] Among them, R1 represents the first reaction mechanism; R2 represents the second reaction mechanism; R3 represents the third reaction mechanism.

[0078] S102, using a zero-dimensional isobaric flame model and hydrocarbon fuel as fuel, a three-step reaction mechanism is performed to determine the maximum temperature when the hydrocarbon fuel is completely burned as the adiabatic equilibrium temperature, and to determine the maximum value point of the temperature change rate during the combustion of the hydrocarbon fuel as the ignition delay.

[0079] The zero-dimensional isobaric flame model is a simplified mathematical model used to describe and analyze the kinetics of chemical reactions. It is particularly suitable for studying the early stages of fuel combustion, such as the ignition process and the calculation of adiabatic equilibrium temperature. The "zero-dimensional" here means that the model ignores the spatial dimension and assumes that the reaction takes place in an infinitely small, uniform volume, without considering the spatial distribution of the flame front or the reaction area. "Isobaric" means that the entire process takes place at a constant pressure without the influence of changes in external pressure.

[0080] In practical applications, numerical methods can be used to solve the model equations to obtain the temperature, pressure and substance concentration that change at any time, and to extract key information from the calculation results, that is, to extract the highest temperature when the hydrocarbon fuel is completely burned as the adiabatic equilibrium temperature.

[0081] For the ignition delay, the ignition delay is defined as the maximum value of the temperature change rate, or the maximum point of the concentration of a certain intermediate product. In an optional embodiment of the present application, the maximum value of the temperature change rate is used to represent the ignition delay. According to dimensional analysis, the distribution of the ignition delay with pressure and temperature can be obtained. Specifically, the ignition delay can be represented by the following formula (2):

[0082]

[0083] Wherein, τ is the ignition delay; P is the reaction pressure; n is the reaction order; n1 is the fuel reaction order; E ais the activation energy; is the equivalence ratio; T is the temperature; R is the gas constant

[0084] The reaction order and activation energy can be obtained based on the distribution of the ignition delay with pressure and temperature given in the above formula (2) combined with known data fitting, but the value of the reaction order should give priority to ensuring the accuracy of the laminar flame speed.

[0085] S103, using a one-dimensional isobaric flame model and hydrocarbon fuel as fuel, a three-step reaction mechanism is performed to determine the reaction pressure, and the laminar flame speed is determined according to the exponential relationship between the reaction pressure and the laminar flame speed.

[0086] The one-dimensional isobaric flame model is used to describe and analyze the combustion process in which the flame propagates along a single spatial dimension under constant pressure. This model is usually used to study the propagation characteristics of laminar flames, such as laminar flame speed, and to analyze the influence of chemical reaction kinetics on flame propagation.

[0087] In the one-dimensional isobaric flame model, the flame is regarded as a thin, infinitely long layer that propagates only in one direction (usually the x-axis), while ignoring changes in other directions. The model assumes that the pressure remains constant throughout the system, that is, isobaric conditions, which allows the model to focus on analyzing the changes in temperature, concentration, and velocity with space and time without considering the effects of pressure gradients.

[0088] In the embodiment of the present application, the above S103 includes:

[0089] Introducing a third body effect into the first reaction mechanism of the three-step reaction mechanism;

[0090] The reaction pressure is determined by a one-dimensional isobaric flame model, using hydrocarbon fuel as fuel and a three-step reaction mechanism introducing a third body effect, and the laminar flame speed is determined according to the exponential relationship between the reaction pressure and the laminar flame speed.

[0091] Specifically, the first reaction mechanism introducing the third body effect can be expressed as follows:

[0092]

[0093] Wherein, M represents a catalyst. In practical application, the catalyst M may be nitrogen.

[0094] The calculation of laminar flame speed is crucial to the prediction of flame structure. Combustion efficiency estimation, combustion chamber optimization, nozzle and cooling channel design all rely on the accurate prediction of flame structure. Therefore, it is necessary to verify the simplified reaction mechanism through laminar flame speed. The laminar flame speed is calculated from the one-dimensional steady-state premixed combustion equation. According to the dimensional calculation, the exponential relationship between the laminar flame speed and pressure can be obtained. Specifically, the exponential relationship between the laminar flame speed and pressure is expressed by the following formula (3):

[0095]

[0096] Among them, S L is the laminar flame speed; P is the reaction pressure; n is the reaction order; λ is the thermal conductivity; C P is the isobaric specific heat capacity; E a is the activation energy; T b is the burnt gas temperature; R is the gas constant.

[0097] In practical applications, the laminar flame speed can be changed by adjusting the third system number of the catalyst without changing the reaction rate parameters.

[0098] Furthermore, in order to ensure that the turbulent combustion characteristics can be predicted quickly and accurately over a wide range of operating conditions ([0.1, 2] equivalence ratio, [1, 1000] times atmospheric pressure, [300, 1000] K initial temperature, and [0, 4] nitrogen-oxygen ratio), the three-step reaction mechanism can also be optimized based on the prediction results of the turbulent combustion characteristics.

[0099] Among them, in the three-step reaction mechanism, the introduction of hydrogen can ensure that the adiabatic equilibrium temperature error of the burning of hydrocarbon fuels in air and pure oxygen is within the preset threshold; the laminar flame speed can be changed by adjusting the third system number of the catalyst without changing the reaction rate parameters; compared with the adiabatic equilibrium temperature and laminar flame speed, the ignition delay has little effect on steady-state combustion, but in unsteady-state combustion, a large ignition delay deviation will greatly change the transient flame structure and temperature. Specifically, the ignition delay can be changed by adjusting the reaction order n, while giving priority to ensuring the accuracy of the laminar flame speed, or by adjusting the activation energy E a Change.

[0100] Specifically, the method for predicting turbulent combustion characteristics further includes the following S104 and S105:

[0101] S104, determining a control turbulent combustion characteristic based on the detailed mechanism and the skeleton mechanism.

[0102] S105, determining whether the difference between the control turbulent combustion characteristics and the turbulent combustion characteristics is greater than a preset threshold; if the difference between the control turbulent combustion characteristics and the turbulent combustion characteristics is greater than the preset threshold, adjusting the third body effect, reaction order and activation energy of the three-step reaction mechanism until the difference between the control turbulent combustion characteristics and the turbulent combustion characteristics is less than or equal to the preset threshold.

[0103] The detailed mechanism refers to the chemical reaction network that contains all known reaction paths of fuel combustion. It usually includes hundreds or even thousands of reactions and species, covering the detailed steps of fuel molecule cracking, recombination, oxidation and other side reactions. The detailed mechanism strives to describe the chemical kinetics of the fuel combustion process as comprehensively and accurately as possible, so it can provide the most accurate combustion simulation results.

[0104] The skeleton mechanism refers to a simplified chemical reaction network that is extracted from the detailed mechanism through a series of screening and simplification processes. The skeleton mechanism retains the most important reaction paths and species in the detailed mechanism, while removing those reactions that have little impact on the overall combustion process to reduce computational complexity and improve simulation efficiency.

[0105] Specifically, the above S104 means that the preliminarily estimated reaction rate parameters are used as input variables, the adiabatic flame temperature, laminar flame speed and ignition delay are calculated under the wide operating range, and compared with the calculation results of the detailed excitation and skeleton mechanism. If the error between the two is greater than a preset threshold (such as 10%), the third system coefficient of the catalyst, the reaction order and the activation energy can be adjusted until the error between the two is within the preset threshold.

[0106] In summary, the method for predicting turbulent combustion characteristics provided in the embodiments of the present application constructs a three-step reaction mechanism by using hydrocarbon fuel, oxygen, carbon monoxide, carbon dioxide, oxygen and water as a component system, so that hydrogen, an intermediate product produced by the reaction of hydrocarbon fuel and oxygen, is introduced into the three-step reaction mechanism, thereby greatly improving the accuracy of the adiabatic equilibrium temperature while maintaining a relatively low cost.

[0107] Furthermore, in the embodiment of the present application, a third system parameter of the catalyst is introduced into the first reaction mechanism in which the hydrocarbon fuel and the oxygen are used as reaction fuels at the same time, so as to meet the laminar flame speed in both air and pure oxygen environments.

[0108] Furthermore, the turbulent combustion characteristics provided in the embodiments of the present application can determine the distribution of the ignition delay with pressure and temperature, so that the ignition delay can be determined in combination with the reaction order, and the accuracy of the ignition delay can be guaranteed while satisfying the laminar flame speed.

[0109] The present application also provides a device for predicting turbulent combustion characteristics. Figure 2 , Figure 2 A structural diagram of a device for predicting turbulent combustion characteristics provided in an embodiment of the present application.

[0110] like Figure 2 As shown, the prediction device for turbulent combustion characteristics comprises:

[0111] The mechanism construction unit 201 is used to construct a three-step reaction mechanism using hydrocarbon fuel, oxygen, carbon monoxide, carbon dioxide, oxygen and water as a component system, wherein the three-step reaction mechanism includes a first reaction mechanism using the hydrocarbon fuel and the oxygen as reaction fuels, and the products of the first reaction mechanism are carbon monoxide and hydrogen; a second reaction mechanism using the carbon monoxide and the oxygen as reaction fuels, and the product of the second reaction mechanism is carbon dioxide; a third reaction mechanism using the hydrogen and the oxygen as reaction fuels, and the product of the third reaction mechanism is water;

[0112] The first reaction unit 202 is used to perform a three-step reaction mechanism using a zero-dimensional isobaric flame model with hydrocarbon fuel as fuel, determine the maximum temperature when the hydrocarbon fuel is completely burned as the adiabatic equilibrium temperature, and determine the maximum value point of the temperature change rate during the combustion of the hydrocarbon fuel as the ignition delay;

[0113] The second reaction unit 203 is used to determine the reaction pressure by a one-dimensional isobaric flame model and a three-step reaction mechanism using hydrocarbon fuel as fuel, and to determine the laminar flame speed according to the exponential relationship between the reaction pressure and the laminar flame speed;

[0114] Among them, the adiabatic equilibrium temperature, the ignition delay and the laminar flame speed are the turbulent combustion characteristics.

[0115] In an optional embodiment of the present application, the three-step reaction mechanism is represented by the following method:

[0116] R1:

[0117] R2:

[0118] R3:

[0119] Among them, R1 represents the first reaction mechanism; R2 represents the second reaction mechanism; R3 represents the third reaction mechanism.

[0120] In an optional embodiment of the present application, the one-dimensional isobaric flame model is used to carry out a three-step reaction mechanism with hydrocarbon fuel as fuel, determine the reaction pressure, and determine the laminar flame speed according to the exponential relationship between the reaction pressure and the laminar flame speed, including:

[0121] Introducing a third body effect into the first reaction mechanism of the three-step reaction mechanism;

[0122] The reaction pressure is determined by a one-dimensional isobaric flame model, using hydrocarbon fuel as fuel and a three-step reaction mechanism introducing a third body effect, and the laminar flame speed is determined according to the exponential relationship between the reaction pressure and the laminar flame speed.

[0123] In an optional embodiment of the present application, the first reaction mechanism of introducing the third body effect is represented by the following method:

[0124] R1:

[0125] Wherein, M represents a catalyst.

[0126] In an optional embodiment of the present application, the exponential relationship between the reaction pressure and the laminar flame speed is expressed by the following formula:

[0127]

[0128] Among them, S L is the laminar flame speed; P is the reaction pressure; n is the reaction order; λ is the thermal conductivity; C P is the isobaric specific heat capacity; E a is the activation energy; T b is the burnt gas temperature; R is the gas constant.

[0129] In an optional implementation manner of the present application, the ignition delay is expressed by the following formula:

[0130]

[0131] Wherein, τ is the ignition delay; P is the reaction pressure; n is the reaction order; n1 is the fuel reaction order; E a is the activation energy; is the equivalence ratio; T is the temperature; R is the gas constant.

[0132] In an optional embodiment of the present application, the device is also used for:

[0133] Determine the comparative turbulent combustion characteristics based on detailed and skeleton mechanisms;

[0134] Determine whether the difference between the control turbulent combustion characteristics and the turbulent combustion characteristics is greater than a preset threshold; if the difference between the control turbulent combustion characteristics and the turbulent combustion characteristics is greater than the preset threshold, adjust the third body effect, reaction order and activation energy of the three-step reaction mechanism until the difference between the control turbulent combustion characteristics and the turbulent combustion characteristics is less than or equal to the preset threshold.

[0135] The above-mentioned device embodiment provided in this embodiment belongs to the same application concept as the method embodiment of this application, and can execute the prediction method of turbulent combustion characteristics provided in any of the above-mentioned embodiments of this application, and has the corresponding functional modules and beneficial effects of executing the prediction method of turbulent combustion characteristics. For technical details not fully described in this embodiment, please refer to the specific processing content of the prediction method of turbulent combustion characteristics provided in the above-mentioned embodiments of this application, and will not be repeated here.

[0136] It should be understood that the units in the above devices can be implemented in the form of a processor calling software. For example, the device includes a processor, the processor is connected to a memory, and instructions are stored in the memory. The processor calls the instructions stored in the memory to implement any of the above methods or realize the functions of each unit of the device, wherein the processor can be a general-purpose processor, such as a CPU or a microprocessor, etc., and the memory can be a memory in the device or a memory outside the device. Alternatively, the units in the device can be implemented in the form of hardware circuits, and the functions of some or all units can be realized by designing the hardware circuits. The hardware circuit can be understood as one or more processors; for example, in one implementation, the hardware circuit is an ASIC, and the functions of some or all of the above units are realized by designing the logical relationship of the components in the circuit; for another example, in another implementation, the hardware circuit can be implemented by PLD, taking FPGA as an example, which can include a large number of logic gate circuits, and the connection relationship between the logic gate circuits is configured by the configuration file, so as to realize the functions of some or all of the above units. All units of the above devices can be implemented in the form of a processor calling software, or in the form of hardware circuits, or in part by a processor calling software, and the remaining part is implemented in the form of hardware circuits.

[0137] In an embodiment of the present application, a processor is a circuit with the ability to process signals. In one implementation, the processor may be a circuit with the ability to read and run instructions, such as a CPU, a microprocessor, a GPU, or a DSP; in another implementation, the processor may implement certain functions through the logical relationship of a hardware circuit, and the logical relationship of the hardware circuit is fixed or reconfigurable, such as a hardware circuit implemented by an ASIC or PLD, such as an FPGA. In a reconfigurable hardware circuit, the process of the processor loading a configuration document to implement the hardware circuit configuration can be understood as the process of the processor loading instructions to implement the functions of some or all of the above units. In addition, it can also be a hardware circuit designed for artificial intelligence, which can be understood as an ASIC, such as an NPU, TPU, DPU, etc.

[0138] It can be seen that each unit in the above device can be one or more processors (or processing circuits) configured to implement the above method, such as: CPU, GPU, NPU, TPU, DPU, microprocessor, DSP, ASIC, FPGA, or a combination of at least two of these processor forms.

[0139] In addition, all or part of the units in the above device can be integrated together, or can be implemented independently. In one implementation, these units are integrated together and implemented in the form of a SOC. The SOC may include at least one processor for implementing any of the above methods or implementing the functions of each unit of the device. The type of the at least one processor may be different, for example, including a CPU and an FPGA, a CPU and an artificial intelligence processor, a CPU and a GPU, etc.

[0140] The present application also provides an electronic device, such as Figure 3 As shown, Figure 3 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application.

[0141] like Figure 3 As shown, the electronic device comprises:

[0142] Processor 210;

[0143] A memory 200 for storing instructions executable by the processor 210;

[0144] The processor 210 is used to execute the method for predicting turbulent combustion characteristics disclosed in any of the above embodiments by running instructions in the memory 200.

[0145] The processor 210, the memory 200, the communication interface 220, the input device 230 and the output device 240 are connected to each other via a bus.

[0146] A bus may include a pathway that transfers information between components of a computer system.

[0147] The processor 210 may be a general-purpose processor, such as a general-purpose central processing unit (CPU), a microprocessor, etc., or an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of the program of the scheme of the present invention. It may also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0148] The processor 210 may include a main processor, and may also include a baseband chip, a modem, and the like.

[0149] The memory 200 stores a program for executing the technical solution of the present invention, and may also store an operating system and other key services. Specifically, the program may include a program code, and the program code includes a computer operation instruction. More specifically, the memory 200 may include a read-only memory (ROM), other types of static storage devices that can store static information and instructions, a random access memory (RAM), other types of dynamic storage devices that can store information and instructions, a disk storage, a flash, and the like.

[0150] The input device 230 may include a device for receiving data and information input by a user, such as a keyboard, a mouse, a camera, a scanner, a touch screen, etc.

[0151] Output device 240 may include devices that allow information to be output to a user, such as a display screen, printer, speaker, etc.

[0152] The communication interface 220 may include any transceiver or the like to communicate with other devices or communication networks, such as Ethernet, Radio Access Network (RAN), Wireless Local Area Network (WLAN), etc.

[0153] The processor 210 executes the program stored in the memory 200 and calls other devices, which can be used to implement each step of any turbulent combustion characteristic prediction method provided in the above embodiments of the present application.

[0154] In addition to the above-mentioned methods and devices, embodiments of the present application may also be a computer program product, which includes computer program instructions, which, when executed by a processor, enable the processor to execute the steps in the method for predicting turbulent combustion characteristics of various embodiments of the present application.

[0155] The computer program product may be written in any combination of one or more programming languages ​​to write program codes for performing the operations of the embodiments of the present application, including object-oriented programming languages, such as Java, C++, etc., and conventional procedural programming languages, such as "C" language or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as an independent software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0156] In addition, the embodiments of the present application may also be a storage medium on which a computer program is stored, and the computer program is executed by a processor to execute the steps in the method for predicting turbulent combustion characteristics of various embodiments of the present application.

[0157] For the aforementioned method embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the order of the actions described, because according to the present application, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0158] It should be noted that each embodiment in this specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other. For the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0159] The steps in the methods of each embodiment of the present application can be adjusted in order, combined and deleted according to actual needs, and the technical features recorded in each embodiment can be replaced or combined.

[0160] The modules and sub-modules in the devices and terminals in the various embodiments of the present application can be combined, divided and deleted according to actual needs.

[0161] In the several embodiments provided in the present application, it should be understood that the disclosed terminals, devices and methods can be implemented in other ways. For example, the terminal embodiments described above are only schematic, for example, the division of modules or submodules is only a logical function division, and there may be other division methods in actual implementation, for example, multiple submodules or modules can be combined or integrated into another module, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or modules, which can be electrical, mechanical or other forms.

[0162] The modules or submodules described as separate components may or may not be physically separated, and the components of the modules or submodules may or may not be physical modules or submodules, that is, they may be located in one place, or they may be distributed on multiple network modules or submodules. Some or all of the modules or submodules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0163] In addition, each functional module or submodule in each embodiment of the present application may be integrated into one processing module, or each module or submodule may exist physically separately, or two or more modules or submodules may be integrated into one module. The above-mentioned integrated modules or submodules may be implemented in the form of hardware or in the form of software functional modules or submodules.

[0164] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0165] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly by hardware, software units executed by a processor, or a combination of the two. The software units may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0166] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0167] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for predicting turbulent combustion characteristics, characterized in that: include: A three-step reaction mechanism is constructed by using hydrocarbon fuel, oxygen, carbon monoxide, carbon dioxide, oxygen and water as a component system, wherein the three-step reaction mechanism includes a first reaction mechanism using the hydrocarbon fuel and the oxygen as reaction fuels, and the products of the first reaction mechanism are carbon monoxide and hydrogen; a second reaction mechanism using the carbon monoxide and the oxygen as reaction fuels, and the product of the second reaction mechanism is carbon dioxide; a third reaction mechanism using the hydrogen and the oxygen as reaction fuels, and the product of the third reaction mechanism is water; Using a zero-dimensional isobaric flame model, a hydrocarbon fuel is used as fuel to carry out a three-step reaction mechanism, and the maximum temperature when the hydrocarbon fuel is completely burned is determined as the adiabatic equilibrium temperature, and the maximum value point of the temperature change rate during the combustion of the hydrocarbon fuel is determined as the ignition delay; By using a one-dimensional isobaric flame model, a three-step reaction mechanism is performed using hydrocarbon fuel as fuel, the reaction pressure is determined, and the laminar flame speed is determined based on the exponential relationship between the reaction pressure and the laminar flame speed; Among them, the adiabatic equilibrium temperature, the ignition delay and the laminar flame speed are the turbulent combustion characteristics.

2. The method according to claim 1, characterized in that: The three-step reaction mechanism is represented by the following: R1： R2： R3： Among them, R1 represents the first reaction mechanism; R2 represents the second reaction mechanism; R3 represents the third reaction mechanism.

3. The method according to claim 1, characterized in that The method comprises: determining the reaction pressure by using a one-dimensional isobaric flame model, taking hydrocarbon fuel as fuel, performing a three-step reaction mechanism, and determining the laminar flame speed according to the exponential relationship between the reaction pressure and the laminar flame speed, including: Introducing a third body effect into the first reaction mechanism of the three-step reaction mechanism; The reaction pressure is determined by a one-dimensional isobaric flame model, using hydrocarbon fuel as fuel and a three-step reaction mechanism introducing a third body effect, and the laminar flame speed is determined according to the exponential relationship between the reaction pressure and the laminar flame speed.

4. The method according to claim 3, characterized in that The first reaction mechanism introducing the third body effect is expressed as follows: R1： Wherein, M represents a catalyst.

5. The method according to claim 3 or 4, characterized in that: The exponential relationship between the reaction pressure and the laminar flame speed is expressed by the following formula: Among them, S L is the laminar flame speed; P is the reaction pressure; n is the reaction order; λ is the thermal conductivity; C P is the isobaric specific heat capacity; E a is the activation energy; T b is the burnt gas temperature; R is the gas constant.

6. The method according to claim 1, characterized in that The ignition delay is expressed by the following formula: Wherein, τ is the ignition delay; P is the reaction pressure; n is the reaction order; n1 is the fuel reaction order; E a is the activation energy; is the equivalence ratio; T is the temperature; R is the gas constant.

7. The method according to claim 1, characterized in that Also includes: Determine the comparative turbulent combustion characteristics based on detailed and skeleton mechanisms; Determine whether the difference between the control turbulent combustion characteristics and the turbulent combustion characteristics is greater than a preset threshold; if the difference between the control turbulent combustion characteristics and the turbulent combustion characteristics is greater than the preset threshold, adjust the third body effect, reaction order and activation energy of the three-step reaction mechanism until the difference between the control turbulent combustion characteristics and the turbulent combustion characteristics is less than or equal to the preset threshold.

8. A device for predicting turbulent combustion characteristics, characterized in that: include: A mechanism construction unit, for constructing a three-step reaction mechanism using hydrocarbon fuel, oxygen, carbon monoxide, carbon dioxide, oxygen and water as a component system, wherein the three-step reaction mechanism includes a first reaction mechanism using the hydrocarbon fuel and the oxygen as reaction fuels, and the products of the first reaction mechanism are carbon monoxide and hydrogen; a second reaction mechanism using the carbon monoxide and the oxygen as reaction fuels, and the product of the second reaction mechanism is carbon dioxide; a third reaction mechanism using the hydrogen and the oxygen as reaction fuels, and the product of the third reaction mechanism is water; The first reaction unit is used to perform a three-step reaction mechanism using a zero-dimensional isobaric flame model with a hydrocarbon fuel as fuel, determine the maximum temperature when the hydrocarbon fuel is completely burned as the adiabatic equilibrium temperature, and determine the maximum value point of the temperature change rate during the combustion of the hydrocarbon fuel as the ignition delay; The second reaction unit is used to determine the reaction pressure by a one-dimensional isobaric flame model and a three-step reaction mechanism using hydrocarbon fuel as fuel, and to determine the laminar flame speed according to the exponential relationship between the reaction pressure and the laminar flame speed; Among them, the adiabatic equilibrium temperature, the ignition delay and the laminar flame speed are the turbulent combustion characteristics.

9. An electronic device, characterized in that: include: processor; a memory for storing instructions executable by the processor; The processor is used to execute the method for predicting turbulent combustion characteristics as described in any one of claims 1 to 7 by running the instructions in the memory.

10. A computer storage medium, characterized in that: The computer storage medium stores instructions, and when the instructions are executed, the method for predicting turbulent combustion characteristics according to any one of claims 1 to 7 is implemented.

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