Catalytic cracking molecular-level modeling method considering heat balance

Abstract

The invention provides a catalytic cracking molecular modeling method considering heat balance, which comprises the following steps of: investigating the actual production condition of a refinery plant, analyzing the typical raw material processing condition of a device, collecting the operation data of the device, including analysis and DCS (Distributed Control System) and the like, then preprocessing the collected data, and screening out a steady-state working condition; establishing a device molecule library in combination with the collected analysis and detection data, and establishing a'macroscopic index-molecular composition 'analytical algorithm; establishing a molecular dynamics reaction network in combination with catalytic cracking reaction raw materials and product conditions, and establishing a riser reactor model in combination with riser geometric parameters and reaction kinetics; then, constructing a regenerator model, then, constructing heat balance and carbon balance of a reaction-regeneration system by taking a catalyst as a medium, and finally, calibrating the model in combination with a plurality of groups of actual working conditions, thereby improving the prediction precision of the model.

Description

Technical Field

[0001] The invention belongs to the technical field of petrochemical industry, and in particular relates to a catalytic cracking molecular modeling method considering thermal balance. Background Art

[0002] In traditional catalytic cracking unit models, most models are based on lumped components to describe the reaction laws in the riser. Although this method can describe the reaction process to a certain extent, it has obvious limitations in dealing with feed fluctuations and predicting product properties (such as distillation range, octane number, carbon number-group composition). In particular, in terms of the impact of catalytic cracking feed fluctuations, models based on lumped components often find it difficult to adapt to and accurately describe these changes, resulting in insufficient accuracy in predicting product properties.

[0003] In recent years, a few studies have begun to use molecular-level composition to build models of catalytic cracking units, especially for the riser section of the unit. However, due to the difficulty of modeling and solving, these models usually do not consider the heat balance of the regenerator and the reverse regeneration system, which limits the application of the model in the exploration of actual production conditions. If the heat balance of these key parts is not considered, the optimization results of the unit based on molecular-level modeling are difficult to provide real guidance for production practice. Summary of the invention

[0004] The object of the present invention is to provide a catalytic cracking molecular modeling method taking into account heat balance, which can more accurately predict the impact of feed fluctuations on the catalytic cracking process and the detailed properties of the products, thereby providing more detailed and practical guidance for the optimization and operation of the catalytic cracking unit.

[0005] The present invention provides a catalytic cracking molecular modeling method considering heat balance, which investigates the actual production situation of the refinery, analyzes the typical raw material processing situation of the device, and collects the device operation data including analysis and DCS data, then performs data preprocessing on the collected data, and screens out the steady-state operating conditions; establishes a device molecular library in combination with the collected analysis and detection data, and establishes a "macro-indicator-molecular composition" analytical algorithm; establishes a molecular dynamics reaction network in combination with the catalytic cracking reaction raw materials and product conditions, and constructs a riser reactor model in combination with the riser geometric parameters and reaction kinetics; then constructs a regenerator model, and then constructs the heat balance and carbon balance of the reverse and regeneration system using the catalyst as the medium, and finally calibrates the model in combination with multiple groups of actual operating conditions, thereby improving the model prediction accuracy.

[0006] The method of the present invention combines molecular refining technology and covers not only the riser section of the unit, but also the heat balance of the regenerator and the regeneration system. This model can more accurately predict the impact of feed fluctuations on the catalytic cracking process and the detailed properties of the products, thereby providing more sophisticated and practical guidance for the optimization and operation of the catalytic cracking unit.

[0007] The present invention also provides a computer-readable storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute the molecular-level modeling method and device for catalytic cracking considering thermal equilibrium as described above.

[0008] The present invention provides a catalytic cracking molecular modeling method considering heat balance, 1) considering the feed composition of the heavy oil riser and the reaction law occurring in the corresponding riser. The reaction network of the device is established through molecular-level composition, and the principles of mass conservation, heat conservation, momentum conservation, etc. are comprehensively considered to establish a molecular-level riser model, which ensures the accurate description of the feed composition and considers the influence of the reaction law on the flow in the riser; 2) considering the coke combustion kinetics, the dilute dense phase bed in the regenerator, the external heat exchanger and other parts, the regenerator model of the device is established. In this step, the kinetic process of coke combustion, the formation of the dilute dense phase bed in the regenerator and the heat exchange process are considered, and the regenerator model is established in combination with the heat exchange effect of the external heat exchanger; 3) using the catalyst as the medium, the heat balance and carbon balance between the riser and the regenerator are considered. Through the transfer effect of the catalyst between the riser and the regenerator, the heat balance and carbon balance of the device are considered, ensuring the stability and efficiency of the entire system during operation. The present application scheme incorporates various parts of the catalytic cracking unit into molecular-level modeling, thereby improving the accuracy of simulation analysis and providing a reliable theoretical basis for the optimal design and operation of the catalytic cracking unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0010] Figure 1 A schematic diagram of a molecular-level modeling method for catalytic cracking considering heat balance of the present invention;

[0011] Figure 2 This is a schematic diagram of the core structure of some molecules selected from the embodiments of the present invention;

[0012] Figure 3 This is a schematic diagram of molecular structure-oriented lumping in an embodiment of the present invention;

[0013] Figure 4 It is a schematic diagram of heat balance and carbon balance of the reaction regeneration system of the present invention;

[0014] Figure 5The product yield in the embodiment of the present invention changes in the riser;

[0015] Figure 6 This is the changing rule of material molecules in the lifting pipe in the embodiment of the present invention. DETAILED DESCRIPTION

[0016] See also Figure 1 , Figure 1 A schematic flow chart of a catalytic cracking molecular-level modeling method and device considering heat balance provided in an embodiment of the present invention includes steps S1 to S10, and each step is specifically as follows:

[0017] Step S1: Plant investigation: Through on-site investigation of the refinery and study of plant data, the source of raw materials and product destination of the plant, the DCS instrument deviation of the plant, the frequency and items of material testing, material balance processing methods, structure and size information of the plant, catalyst and additive information, etc. are sorted out.

[0018] Step S2: Typical sample analysis. According to the historical fluctuation of the raw materials of the plant and the future processing plan, three groups of typical import and export materials are generally collected and sent to a professional oil product testing and analysis agency to conduct composition analysis on the distillate oil.

[0019] Step S3: Data preprocessing, collect the operating data of the catalytic cracking unit, raw material test data and product test data for preprocessing. The preprocessing here refers to aligning the timestamp of the data and deleting outliers. For operating data (or DCS data), the sliding window detection method is adopted, and the outlier refers to the point in the sliding window that differs from the local median by more than 3 times. For the test data, it is necessary to analyze according to the physical meaning of the specific property indicators, such as the gasoline distillation range, the initial distillation point is generally greater than 30°C and the distillation temperature gradually increases with the increase of the volume fraction. When it does not meet the constraints of these general rules, it is identified as an outlier; other non-distillation properties can be judged according to the mean of historical test data combined with the 3σ criterion.

[0020] Step S4: Screening steady-state conditions, screening the pre-processed operating data and test data through steady-state algorithms and material balance constraints to obtain steady-state conditions of the device.

[0021] Step S5: set up device molecular library, according to the steady state working condition data after the chemical analysis result of step S2 and step S4 process, in conjunction with the reaction law of device light oil riser and heavy oil riser, set up device molecular library.Reaction law here refers to alkane (normal + isomerization) cracking, olefin (normal + isomerization) cracking, cycloalkane side chain breaking, aromatic side chain breaking, cycloalkane ring opening, cycloalkane dehydrogenation, olefin isomerization, olefin hydrogen transfer, olefin cyclization, aromatic condensation etc.The molecular library set up should be able to cover the above-mentioned reaction between alkane, olefin, cycloalkane, aromatics, so that the molecular library can include the reactant molecules of each family, and also can include corresponding product molecules.For example, n-heptane is cracked into propylene and normal butane, so the molecular library will include normal heptane, propylene and normal butane. The construction of the molecular library adopts different strategies in different fractions. For the methane to gasoline section, the molecular library of the light oil section is established based on the monomer hydrocarbons obtained by chemical analysis. For heavy oils such as diesel, wax oil, and residual oil, the heavy oil molecular library is established based on the principle of molecular core plus branch chain expansion. Finally, the light oil and heavy oil molecular libraries are combined as the device molecular library. Figure 2 The following is a schematic diagram of the core structure of some selected molecules. It should be noted that branch extension also adopts different methods for different family compositions and fractions. For example, if the carbon number-equivalent double bond number (DBE) segment is denser in the test analysis results, the corresponding molecular carbon number distribution after branch extension will be denser. In addition, generally, as the distillation temperature increases from diesel to wax oil, the carbon number distribution of the molecule after branch extension will gradually become sparse.

[0022] Step S6: Establish a molecular analysis algorithm, based on the molecular library established in step S5, the detection data of step S2 and the test data of step S4, establish a molecular analysis algorithm for the raw materials of the device. Specifically, the molecular concentration information of the typical sample is obtained according to the S2 test data to establish a reference molecular library, and the molecular concentration information here (various component compound contents, DBE distribution, etc.) is summarized as a certain distribution law, that is, the distribution function (such as β distribution function or α distribution function, etc.) is used for parameter fitting. This patent assumes that when the macroscopic properties of the stream, such as the density distillation range, etc., change, the distribution law of its molecular concentration is generally similar, and only the distribution function needs to be fine-tuned on the basis of the reference library. Then this distribution law is applied to the molecular library established in step S5, and a group of concentrations of each molecule in the molecular library is obtained, and then the macroscopic properties of the stream, such as the density distillation range, etc., are calculated based on the physical property algorithm according to this group of molecular concentrations. When it is found that there is a deviation between the calculated macroscopic physical properties and the raw material macroscopic property data in the steady-state data obtained in step S4, the parameters of the distribution function are adjusted until the two reach a numerical value close to each other, that is, the establishment of the molecular analysis algorithm is completed. The molecular analysis algorithm can obtain the molecular composition of the raw materials from the macroscopic properties of conventional tests such as distillation range, density, sulfur and nitrogen content, and provide input for subsequent mechanism models.

[0023] Step S7: Establish reaction kinetics. According to the laws of catalytic cracking reactions in the literature and the reaction characteristics of the catalysts of the catalyst manufacturers, the catalytic cracking reactions and some thermal cracking reactions occurring in the light oil riser and the heavy oil riser are summarized and summarized, and a total of 28 major reaction rules are formed, including the cracking of normal isomerized alkanes, cracking of normal isomerized olefins, cycloalkane side chain scission, aromatic side chain scission, cycloalkane ring opening, cycloalkane dehydrogenation, olefin isomerization, alkane isomerization, olefin hydrogen transfer, olefin cyclization, and aromatic condensation. The molecules are described by structure-oriented lumping, and the reaction rules describing the molecular relationships are digitized. The digitization here first uses the structure-oriented lumping (SOL) method to represent each molecule in the molecular library, that is, each molecule is represented by a vector. In the structure-oriented lumping method, the following is used: Figure 3 A set of symbols is shown to represent molecules. If each fragment does not exist in the molecule, it is represented by 0. If it exists, it is represented by the number of existence. For example, toluene is expressed by SOL as "A6=1, R=1", and its vector expression is [1 0 0 0 0 0 0 0 0 1 0 0 0 0 00 0 0 0 0], and naphthalene is "A6=1, A4=1", and its vector expression is [1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]. The reaction rules are then described by computer, divided into two parts: reactant selection and product generation. The catalytic cracking of alkanes is taken as an example as follows:

[0024] Reactant selection rules:

[0025] (A6+N6+N5==0)&(R>6)&(IH==1)&(RO+RS+RN==0);

[0026] Product generation rules:

[0027] Product 1: R1 = round(3 + (R-6) * rand(1)); IH1 = round(rand(1));

[0028] Product 2: R2 = R-R1; IH2 = IH-IH1;

[0029] Through such reaction rules, the reaction relationship between molecules in the molecular library established in step S5 can be found. According to such reaction relationship, the reaction rate of each molecular level component can be summarized and calculated, wherein the rate expression adopts the Arrhenius formula, thereby establishing a reaction kinetic equation, and its material balance equation can be established for each molecule to complete the digitization of the reaction rules. The kinetic parameters in the Arrhenius formula are calculated by the quantitative structure-activity correlation formula to obtain the initial value. It should be noted that in order to reduce the scale of the model, the reaction kinetics of the light oil riser and the heavy oil riser are established around their respective feeds.

[0030] Step S8: Establish a riser model. Since the riser has a relatively large length-diameter ratio and the flow rate in the pipe is relatively fast, the light oil riser and the heavy oil riser are assumed to be gas-solid plug flow models, and the catalyst and crude oil at the bottom of the riser are ideally mixed. For the convenience of calculation, the two risers are respectively regarded as a collection of micro-element segments. In each micro-element segment, the reaction kinetics equation, the heat balance equation and the momentum balance equation are combined to obtain the molecular concentration, temperature and pressure distribution along the length of the riser through integral calculation.

[0031] Mass balance equation:

[0032]

[0033] In formula 1, F represents the mass flow rate, kg / s; y i represents the mass fraction of component i; x represents the tube length, m; mw i represents the relative molecular mass of component i; A represents the permeable cross-sectional area in the tube, m 2 ; r i,cat represents the catalytic reaction rate of component i; r i,thermal represents the thermal cracking reaction rate of component i; ∈ s represents the volume fraction of the tube occupied by the catalyst;

[0034] Heat balance equation:

[0035]

[0036] In formula 2, T refers to temperature, K; Q refers to heat flux, kJ / m 2 / s;h i Refers to the standard molar production enthalpy of the component, kJ / kmol; Cp i Refers to the heat capacity of each component, kJ / kmol / K; R steam Refers to the mass fraction of steam; Cp steam Refers to the heat capacity of steam, kJ / kmol / K; R cat Refers to the mass fraction of the catalyst; Cp cat Refers to the heat capacity of the catalyst, kJ / kmol / K.

[0037] Momentum balance equation:

[0038]

[0039] In formula 3, P refers to pressure, Pa; f refers to the friction factor, which is related to the Reynolds number, pipe diameter, and the roughness of the inner surface of the pipe; ρ ave Average density, kg / m 3 ;v ave Average flow velocity, m / s;

[0040] Step S9: Establish a regenerator model. For the convenience of calculation, the regenerator is regarded as a dense bed and a dilute bed. It is assumed that the solid phase in the dense bed is adiabatic full mixed flow, the gas phase is plug flow, and the carbon and hydrogen are burned at equal rates. The dilute bed is mainly adiabatic gas phase plug flow. For the charring process in the regenerator, it is assumed that the catalyst returned by the external heat exchanger and the internal circulating catalyst and the catalyst to be regenerated are quickly and ideally mixed.

[0041] The solid phase mainly considers the process of coke combustion, and the coke combustion rate equation is established based on the following relationship:

[0042] Coke → f CO ·CO+(1-f CO )·CO2 Formula 4;

[0043] In formula 4, f CO Refers to the proportion of CO produced by coke combustion.

[0044] In the gas phase, the main consideration is the process of carbon monoxide burning to produce carbon dioxide. The core equation is:

[0045]

[0046] In formula 5 to formula 8, F O2 ,F CO2 ,F CO ,F H2O Represent the flow rates of oxygen, carbon dioxide, carbon monoxide and water respectively, R O2 ,R CO2 ,R CO ,R H2O ,R C They represent the reaction rates of oxygen, carbon dioxide, carbon monoxide, water and coke respectively, and HCR represents the hydrogen-carbon ratio in coke.

[0047] Step S10: Establish the heat balance and carbon balance of the reverse regeneration system with the catalyst as the medium. The heat balance mainly includes three parts: the heat balance of the riser itself, i.e., the balance between the heat supply of the catalyst and the heat required for material heating, the heat required for reaction, etc., the heat balance of the regenerator itself, i.e., the balance between the heat supply of coke combustion and the heat required for main air heating, the heat required for catalyst heating, the heat required for external heat exchanger, etc., and the overall heat balance of the reverse regeneration system, i.e., the catalyst as the carrier, the heat supply of the regenerator and the heat required for the riser. Here, the two equilibrium equations need to be solved simultaneously, and the carbon content of the regenerated catalyst and the dense phase bed temperature of the regenerator are generally calculated iteratively using the Newton method.

[0048] Specific relationships such as Figure 4 As shown, Figure 4 The relationship between the three heat balances and the required variable information of the key streams are shown. The carbon balance mainly considers the carbon balance between the carbon content of the spent catalyst out of the riser outlet, the coke combustion in the regenerator and the carbon content of the regenerated catalyst entering the bottom of the riser from the regenerator.

[0049] The carbon balance equation is:

[0050]

[0051] In formula 9 and formula 10, C in Indicates the mass fraction of carbon content per unit catalyst input to the regenerator, %, C out is the mass fraction of carbon content per unit catalyst output from the regenerator, F co,air and Fco 2，air Respectively represent the mass flow rate of CO and CO2 in the air, kg / s; CCR is the circulation volume of the catalyst, kg / s; α and β represent the phase tube correction parameters;

[0052] The heat balance equation is:

[0053] f2=H air (T air )+H cat,spent (RTT)-(H flue (T flue )+H cat，regen (T regen )+H Cooler +H Loss )=0 Formula 11;

[0054] In formula 11, H air , H cat,spent , H flue , H cat,regen , H cooler , H Loss Respectively represent the enthalpy values ​​of main air, regenerated catalyst, flue gas, regenerated catalyst, external heat, and heat loss, KJ / kmol; Tair ,RTT,T flue ,T regen Respectively represent the temperature of main air, catalyst to be regenerated, flue gas, and regenerator, K;

[0055] Step S11: model calibration, model calibration here refers to setting and adjusting model parameters so that the product yield and density distillation range predicted by the model are close to the product yield and density distillation range in the steady-state condition sorted out in step S4. The model parameters here refer to the pre-exponential factor, activation energy adjustment factor and other related parameters such as heat transfer and pressure drop calculation in the reaction kinetics of light oil riser and heavy oil riser. Model calibration generally sets the initial values ​​of model parameters according to the reaction kinetics data in experience and reference materials, and then selects several groups of steady-state conditions with large changes, and uses the yield of the operating condition data, the difference of the yield and property data predicted by the model as the objective function, and optimizes and adjusts the model parameters based on the initial values ​​with a gradient-based optimization algorithm (generally a sequential quadratic programming method) until the model simulation accuracy reaches the tolerance.

[0056] Table 1 is the prediction accuracy of the catalytic cracking molecular model considering heat balance established by this method. The calculation process of this table, first select three groups of working condition data in the steady-state working condition screened by step S4, input the feed macro data therein into the molecular analysis algorithm established by step S6, and obtain the molecular concentration information of the corresponding working condition raw material. Secondly, the molecular concentration and the operating data (temperature, pressure, flow) in the working condition data are input into the riser model established by step S8, and the energy balance, momentum balance, and material balance equations (including reaction kinetic equations) of the riser part are solved jointly to obtain the composition, temperature and pressure data of the outlet, and then the combustion kinetic equation of the regenerator part is calculated to calculate the combustion heat release of the regenerator part established by step 9, and then the catalyst circulation amount and the carbon content of the catalyst to be generated are calculated according to the results calculated by the above-mentioned riser and regenerator and the heat balance and carbon balance cycle of the reverse regeneration system. The riser outlet composition, temperature and pressure obtained after convergence are the final results, and some data are listed in Table 1.

[0057] Figure 5 and Figure 6 The following is a schematic diagram of the product yield distribution and molecular concentration distribution along the length of the riser output by the model. If it is a lumped model, it is impossible to obtain such Figure 6 The information shown.

[0058] Table 1 Catalytic model calculation yield accuracy table

[0059]

[0060]

[0061] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A molecular modeling method for catalytic cracking considering thermal equilibrium, The following steps are involved: S1) Plant survey, record the raw material source, product destination, DCS instrument deviation, material analysis, material balance processing method, plant structure and size information, catalyst and additive information, and obtain historical fluctuations of the plant and raw materials; S2) Typical sample analysis: according to the historical fluctuations of the unit and raw materials, 3 to 5 groups of typical data are collected for analysis to obtain the operation data of the catalytic cracking unit, raw material test data and product test data; S3) data preprocessing, preprocessing the operation data of the catalytic cracking unit, the raw material test data and the product test data obtained by the analysis in step S2), wherein the preprocessing includes aligning the timestamps of the data and deleting outliers; S4) screening steady-state operating conditions, and obtaining the steady-state operating conditions of the device by screening the data preprocessed in step S3) through a steady-state algorithm and material balance constraints; S5) establishing a molecular library of the device, based on the raw material test data and product test data of step S2) and the steady-state operating data obtained in step S4), and in combination with the reaction types of the light oil riser and the heavy oil riser of the device, establishing a molecular library of the device, wherein the molecular library includes reactant molecules and corresponding product molecules of the reactions involved in the light oil riser and the heavy oil riser; S6) establishing a molecular analysis algorithm, using a distribution function to perform parameter fitting based on the molecular concentration information in the test data of the raw materials and products obtained in step S2), applying the distribution law obtained after fitting to the molecular library established in step S5), obtaining a set of concentration information of each molecule in the molecular library, obtaining macro information of the calculated stream based on the molecular concentration information, and then comparing the obtained macro information with the macro property data of the raw materials in the steady state obtained in step S4), and when the deviation is greater than 3%, adjusting the parameters of the distribution function and refitting until the deviation between the obtained macro information and the macro property data of the raw materials in the steady state obtained in step S4) is less than 3%, thereby obtaining a molecular analysis algorithm; S7) establishing reaction kinetics, obtaining reaction rules according to the types of reactions occurring in the light oil riser and the heavy oil riser, describing molecules in a structure-guided lumping manner, and digitizing the reaction rules describing the molecular relationships to establish reaction kinetic equations; S8) establishing a riser model, assuming the light oil riser and the heavy oil riser to be gas-solid plug flow models, the catalyst and crude oil at the bottom of the riser to be ideal mixing models, and considering the two risers as a collection of micro-element segments. In each micro-element segment, the reaction kinetics equation, the heat balance equation and the momentum balance equation are simultaneously established, and the molecular concentration, temperature and pressure distribution along the length of the riser are obtained by integral calculation; Mass balance equation: In formula 1, F represents the mass flow rate, kg / s; yi represents the mass fraction of component i; x represents the tube length, m; mw i represents the relative molecular mass of component i; A represents the permeable cross-sectional area in the tube, m 2 ; r i,cat represents the catalytic reaction rate of component i; r i,thermal represents the thermal cracking reaction rate of component i; ∈ s represents the volume fraction of the tube occupied by the catalyst; Heat balance equation: In formula 2, T refers to temperature, K; Q refers to heat flux, kJ / m 2 / s;h i Refers to the standard molar production enthalpy of the component, kJ / kmol; Cp i Refers to the heat capacity of each component, kJ / kmol / K; R steam Refers to the mass fraction of steam; Cp steam Refers to the heat capacity of steam, kJ / kmol / K; R cat Refers to the mass fraction of the catalyst; Cp cat Refers to the heat capacity of the catalyst, kJ / kmol / K; Momentum balance equation: In formula 3, P refers to pressure, Pa; f refers to the friction factor, which is related to the Reynolds number, pipe diameter, and the roughness of the inner surface of the pipe; ρ ave Average density, kg / m 3 ;v ave Average flow velocity, m / s; S9) Establish a regenerator model, and regard the regenerator as consisting of a dense bed and a dilute bed. Assume that the solid phase in the dense bed is adiabatic full mixed flow, the gas phase is plug flow, the carbon and hydrogen are burned at a constant rate, and the dilute bed is adiabatic gas phase plug flow; The combustion rate equation for the solid phase is: Coke→f CO ·CO+(1 - f CO )·CO 2 Formula 4; In formula 4, f CO Refers to the proportion of CO produced by coke combustion; The combustion rate equation for the gas phase is: In formula 5 to formula 8, F O2 ,F CO2 ,F CO , F H2O Represent the flow rates of oxygen, carbon dioxide, carbon monoxide and water respectively, R O2 ,R CO2 ,R CO ,R H2O , R C They represent the reaction rates of oxygen, carbon dioxide, carbon monoxide, water and coke, respectively, and HCR represents the hydrogen-carbon ratio in coke; S10) establishing the heat balance and carbon balance of the reaction and regeneration system using the catalyst as a medium, wherein the carbon balance equation is: In formula 9 and formula 10, C in Indicates the mass fraction of carbon content per unit catalyst input to the regenerator, %, C out is the mass fraction of carbon content per unit catalyst output from the regenerator, F co,air and Fco 2，air Represents CO and CO in the air respectively 2 The mass flow rate is kg / s; CCR is the circulation volume of the catalyst, kg / s; α and β represent the phase tube correction parameters respectively; The heat balance equation is: f 2 = H air (T air ) + H catspent (RTT) - (H flue (T flue ) + H cat,regen (T regen ) + H cooler + H Loss ) = 0 Equation 11; In formula 11, H air , H cat,spent , H flue , H cat,regen , H cooler , H Loss Respectively represent the enthalpy values ​​of main air, regenerated catalyst, flue gas, regenerated catalyst, external heat, and heat loss, KJ / kmol; T air ,RTT,T flue , T regen Respectively represent the temperature of main air, catalyst to be regenerated, flue gas, and regenerator, K; S11) Model calibration, by setting and adjusting the model parameters, the product yield and the macro information of the material predicted by the model are made close to the product yield and the macro information of the material in the steady state condition in step S4).

2. The catalytic cracking molecular modeling method considering thermal balance according to claim 1, It is characterized in that In step S3), the outliers of the operating data are detected by a sliding window detection method, and the outliers of the operating data are values ​​within the sliding window that differ from the local median by more than 3 times; In the step S3), the abnormal values ​​of the raw material test data and the product test data are judged according to the physical law and the 3σ criterion of the mean of historical data.

3. The catalytic cracking molecular modeling method considering thermal balance according to claim 1, It is characterized in that In the step S5), the reaction types include one or more of normal alkane cracking, isoalkane cracking, normal olefin cracking, isoolefin cracking, cycloalkane side chain scission, aromatic side chain scission, cycloalkane ring opening, cycloalkane dehydrogenation, olefin isomerization, olefin hydrogen transfer, olefin cyclization and aromatic condensation.

4. The catalytic cracking molecular modeling method considering thermal balance according to claim 1, It is characterized in that In the step S5), a molecular library of the light oil segment is established based on the monomer hydrocarbons obtained from the test data in step S2), and a molecular library of the heavy oil segment is established using the principle of molecular core plus branch chain extension. The molecular library of the light oil segment and the molecular library of the heavy oil segment are combined as the molecular library of the device; The light oil section is a methane to gasoline section, and the heavy oil section includes one or more of diesel, wax oil and residual oil.

5. The catalytic cracking molecular modeling method considering thermal balance according to claim 1, It is characterized in that In the step S6), the molecular concentration information includes the content of each component and the DBE distribution; The macro information of the stream includes the density and distillation range of each component; The distribution function includes a beta distribution function or an alpha distribution function.

6. The catalytic cracking molecular modeling method considering thermal balance according to claim 1, It is characterized in that Molecular analysis algorithms are used to input macro information data from routine tests to obtain the molecular composition of raw materials.

7. The catalytic cracking molecular modeling method considering thermal balance according to claim 1, It is characterized in that In the step S7), a reaction relationship between molecules in the device molecular library is established according to the reaction rules, the reaction rate of each molecule in the reaction relationship is calculated by using the Arrhenius formula, and a material balance equation is established for each molecule to complete the digitization of the reaction rules.

8. The catalytic cracking molecular modeling method considering thermal balance according to claim 1, It is characterized in that The reaction kinetic equations for the light oil riser and the heavy oil riser are established respectively.

9. The catalytic cracking molecular modeling method considering thermal balance according to claim 1, It is characterized in that The heat balance in step S10) includes the heat balance of the riser itself, the heat balance of the regenerator itself and the overall heat balance of the reaction regeneration system; The heat balance of the riser itself includes the balance of heat supply of the catalyst, heat required for material heating, and heat required for reaction; The heat balance of the regenerator itself includes the balance of heat supplied by coke combustion, heat required for main air heating, heat required for catalyst heating, and heat required by external heat exchanger; The overall heat balance of the reaction regeneration system includes the balance of the catalyst as a carrier, the heat supply of the regenerator and the heat demand of the riser.

10. The catalytic cracking molecular modeling method considering thermal balance according to claim 1, It is characterized in that The carbon balance in step S10) includes the carbon balance among the carbon content of the catalyst to be regenerated output from the riser outlet, the amount of coke burned in the regenerator and the carbon content of the regenerated catalyst entering the bottom of the riser from the regenerator.

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