CN109871612A - In conjunction with the heterogeneous catalysis surface coverage acquisition methods of ODE integral and Newton iterative method - Google Patents

In conjunction with the heterogeneous catalysis surface coverage acquisition methods of ODE integral and Newton iterative method Download PDF

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CN109871612A
CN109871612A CN201910122197.9A CN201910122197A CN109871612A CN 109871612 A CN109871612 A CN 109871612A CN 201910122197 A CN201910122197 A CN 201910122197A CN 109871612 A CN109871612 A CN 109871612A
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ode
iteration
coverage
newton
integral
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CN109871612B (en
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曹宵鸣
邵正将
孙希彤
胡培君
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East China University of Science and Technology
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Abstract

The present invention relates to a kind of heterogeneous catalysis surface coverage acquisition methods of combination ODE integral and Newton iterative method, comprising the following steps: 1) starts catalysis simulation;2) one surface coverage of random initializtion, and construct micro kinetics steady-state equation;3) using the coverage of initialization as starting point, steady-state equation is integrated using ODE numerical integration algorithm;4) it after integral reaches specified time, obtains current solving in the initial value feeding Newton iteration device as Newton iteration and carries out Newton iteration;5) if coverage changes with time rate less than convergence precision, it then obtains steady state solution and carries out step 6), if not converged, return step 3) using current solution as the starting point of ODE numerical integration algorithm, continue ODE integral, and repeat step 3) -5);6) catalyst system reaction rate is obtained according to steady state solution.Compared with prior art, the present invention has many advantages, such as not depend on unduly that initial value, to save memory, raising efficiency, flexibility high.

Description

In conjunction with the heterogeneous catalysis surface coverage acquisition methods of ODE integral and Newton iterative method
Technical field
The present invention relates to heterogeneous catalysis micro kinetics simulation fields, more particularly, to a kind of combination ODE integral and newton The heterogeneous catalysis surface coverage acquisition methods of method iteration.
Background technique
Micro kinetics simulate (Microkinetic simulation) connection micro-scale first-principles calculations with Vital role is played in macrodynamics phenomenon, this method has been applied extensively and successfully at present multiple In the various researchs of miscellaneous surface heterogeneous catalysis.Researcher can calculate catalytic body by the quantum chemistry software of business at present The thermodynamics and kinetics energy datum of each possible elementary reaction in system, based on this data and based on the micro- of mean field approximation Seeing dynamic method can be used the reaction rate of the prediction catalyst system of computer rapidly and efficiently and some other macro Property is seen, such as surface composition and the reversible degree of elementary reaction, rate determining step is rapid etc..
Micro kinetics method is a kind of chemical reaction system based on mean field approximation in physical chemistry and steady state approximation The method for numerical simulation of kinetic property.The catalytic cycle that one heterogeneous catalytic reaction system is made of multiple elementary reactions. Wherein each elementary reaction can be indicated by a kind of general reaction equation:
Wherein AiAdsorbate, meteorological molecule or surface vacancy are represented,Indicate AiCoefficient in elementary reaction e,It is that just/back reaction rate of entire elementary reaction can write out the reaction of the elementary reaction by the law of mass action Rate:
Wherein,Indicate adsorbate AiSurface coverage in certain elementary reactions,Meteorological point can also be used The partial pressure of sonIt replaces, for some adsorbing species, can derive that species surface coverage becomes at any time according to above formula The expression formula of rate:
For multiple species, entire catalyst system will obtain one group of ordinary differential system:
According to steady state approximation, when entire catalyst system reaches stable state, the species coverage on surface should keep stable state, That is the coverage rate that changes with time is 0, therefore can convert above-mentioned ordinary differential system to one group of Nonlinear System of Equations:
Entire catalyst system just can be obtained in stable state by solving above-mentioned Nonlinear System of Equations or ordinary differential system The coverage of surface species under state, and then predict the reaction rate and other macroscopic properties of whole system.
It is at present Newton method for the common method for solving micro kinetics equation, Newton method needs at the beginning of previously given one Initial value (initial coverage), is then iterated by Newton iterative, when all species coverages change over time rate Close to 0, at the same be less than some precision (such as 10e-50) when can consider that whole system has reached stable state, Terminate iteration.However, whether the effect of the method iterative solution (can converge to enough precision and reach the solution after precision Whether with reasonable physical significance) depend critically upon iteration initial value value, if the value " unreasonable " of initial value When, Newton iterative method hardly results in final correctly solution.A kind of situation is that iterative algorithm is difficult error convergence to specified essence Degree, and there is the coverage that the convergence of low precision obtains very big error can not use as a result;Second situation is ox The solution that the method for pausing can converge to designated precision, but obtain not is the final reasonable solution with physical significance, such as is solved The coverage of negative out, or it is unsatisfactory for the coverage etc. of conservation of mass relationship.Especially when needing to carry out micro kinetics simulation Catalyst system very complicated (include many elementary reactions) when, the stability and accuracy for solving steady-state equation can be more difficult to ensure Card.
Summary of the invention
It is an object of the present invention to overcome the above-mentioned drawbacks of the prior art and provide a kind of combination ODE integral and The heterogeneous catalysis surface coverage acquisition methods of Newton iterative method.
The purpose of the present invention can be achieved through the following technical solutions:
A kind of heterogeneous catalysis surface coverage acquisition methods of combination ODE integral and Newton iterative method, comprising the following steps:
1) start the micro kinetics simulation of heterogeneous catalysis;
2) one surface coverage of random initializtion, and construct micro kinetics steady-state equation;
3) using the coverage of initialization as starting point, steady-state equation is integrated using ODE numerical integration algorithm;
4) after integral reaches specified time, ODE numerical integration is terminated, and obtains current solution as the first of Newton iteration Initial value is sent into Newton iteration device and carries out Newton iteration;
5) if coverage changes with time rate less than convergence precision, iteration is terminated, steady state solution is obtained and carries out step 6), if not converged, return step 3) using current solution as the starting point of ODE numerical integration algorithm, continue ODE numerical integration, And repeat step 3) -5);
6) catalyst system reaction rate is obtained according to steady state solution.
In the step 2), micro kinetics steady-state equation are as follows:
Wherein,For adsorbate AnCoverage on surface,For adsorbate AnCoefficient in elementary reaction e, re For the reaction rate of elementary reaction.
Convergence precision in the step 5) is 10e-50.
In the step 4), wherein the time span and time step of ODE numerical integration, carry out automatic with hydridization iteration It adjusts, then has:
α × 10 T=N
I=10-(N+2)
Wherein, T is the time span of integral, and I is time step, and α is an adjustable value, and size is between 0~1, N For the number of current hydridization iteration.
In the step 3), ODE numerical integration algorithm uses real value variable coefficient ODE Integration Solving device.
The step 4) specifically includes the following steps:
41) using the solution of ODE numerical integration as initial coverage Θ0
42) iteration direction d is obtained:
43) by iterative rate constant λ=0.5i-1As iteration step length, wherein i is the step number of current Newton iteration;
44) after obtaining iteration direction and step-length, pass through Θk+1k+ λ d updates coverage;
45) iteration is terminated when iteration convergence, otherwise return step 42) until convergence.
Compared with prior art, the invention has the following advantages that
One, the input present invention employs ODE integrated value as Newton method initial value reduces total algorithm for initial Value value is depended on unduly.
Two, ODE integral use low precision numerical value indicate, relative good accuracy floating number indicate, have save memory with And the advantages such as raising efficiency.
Three, ODE integral, can also will be under the process record of surface evolution in addition to can be using integrated value as Newton method input Come, than the information that pure Newton iterative method has more also physical significances.
Four, change hydridization iterative algorithm use multiple hydridization iteration strategy, even if an iteration can not obtain it is convergent Steady state solution, algorithm will continue to repeat ODE/Newton integral handoff procedure, and can be dynamic to adjust integral according to switching times Parameter improves higher flexibility.
Detailed description of the invention
Fig. 1 is flow chart of the method for the present invention.
Fig. 2 is iteration error evolution curve.
Specific embodiment
The present invention is described in detail with specific embodiment below in conjunction with the accompanying drawings.
As shown in Figure 1, present invention employs the hydridization of a kind of low precision ODE integral of combination and high-precision Newton iterative method to change Come for algorithm so that the micro kinetics of heterogeneous catalysis simulates to overcome and depends on initial value unduly and be unable to get steady state solution It is difficult.The ODE integral of low precision can be integrated since arbitrary initial value, to will not depend upon taking for initial coverage Value, when integrating to a certain extent, the coverage of surface species can gradually develop with the time, terminate at a time point of setting ODE integral obtains the current species covering angle value initial point rough as one and is brought into high-precision Newton iteration solution In device, high-precision steady state solution is obtained using Newton method.If Newton method can not still restrain, it is switched in ODE integrator and continues ODE algorithm will be used to carry out solution integral, and repeat to switch between two kinds of algorithms, until the change rate of coverage converges to The standard of holding back obtains steady state solution.
The brief process of the algorithm is as follows:
1) simulation starts;
2) it is randomized an initial surface coverage, constructs micro kinetics steady-state equation;
3) using the coverage of initialization as starting point, steady-state equation is integrated using ODE numerical integration algorithm, the product Usually using real value variable coefficient ODE Integration Solving device in point, which has used fixed-leading-coefficient real It is existing, so as to automatically be switched between implicit Adam method and method based on backward difference formula (BDF);
4) it is integrated to specified time, terminates ODE integral, and obtain current solution and bring into as initial value (initial coverage) High-precision Newton iteration is carried out in Newton iteration device, specially;
It being indicated used here as vector function F and coverage vector theta, such steady-state equation group can be expressed as, wherein Θ * is final steady state solution, and wherein iterative process is as follows:
A) initial coverage Θ 0 (i.e. back ODE integral result) is given;
B) iteration direction d is obtained by solving following formula;
C) iterative rate constant λ=0.5i-1 is calculated as iteration step length, and wherein i is the step number of current Newton iteration;
D) after obtaining iteration direction and step-length, pass through Θi+1i+ λ d updates coverage vector, while making k=k+1;
If e) F (Θ 0) < ε, illustrate iteration convergence, terminates iteration;It is opposite then return b) repeat above procedure;
5) if coverage changes with time rate less than convergence, iteration is terminated;If not converged, return step 3) Using current solution as starting point, integrates, repeat the above steps into ODE;
6) Data Post, based on other macroscopic properties such as steady state solution prediction catalyst system reaction rates.
Embodiment:
The present invention is to assist CO2 catalytic hydrogenation micro kinetics simulative example in Cu (211) surface water
Table 1 show the elementary reaction expression formula in certain paths of Cu (211) surface water auxiliary CO2 catalytic hydrogenation And energy datum, data are calculated by quantum chemistry software VASP and are obtained.Event of whole process can be updated to not with this Dynamics simulation is carried out in same micro kinetics method for solving and in this, as comparison.
The elementary reaction expression formula and energy datum that table 1 is likely to occur
It is compared to compare, uses standard random starting values Newton method and improved ODE/Newton method hydridization respectively Iterative algorithm is solved to above catalyst system progress micro kinetics model, and obtained Newton iterative method error develops bent Line is as shown in Figure 2.
From fig. 2 it can be seen that hydridization iterative algorithm, has just converged to 10e-100 by an ODE/Newton iteration Power, and it is the last solution with reasonable physical significance that finally obtained result is verified.And the standard ox of random initializtion Pause iterative algorithm, is still difficult to converge to correct solution by the iteration of multiple initial values immediately, even if iteration can all be received every time The solution holding back lower error amount, but obtaining but includes negative value (can not have negative value when coverage).As it can be seen that multiple In miscellaneous catalyst system, hydridization iterative algorithm has more acurrate and stable convergence advantage than traditional Newton iterative method.

Claims (6)

1. a kind of heterogeneous catalysis surface coverage acquisition methods of combination ODE integral and Newton iterative method, which is characterized in that including Following steps:
1) start the micro kinetics simulation of heterogeneous catalysis;
2) one surface coverage of random initializtion, and construct micro kinetics steady-state equation;
3) using the coverage of initialization as starting point, steady-state equation is integrated using ODE numerical integration algorithm;
4) after integral reaches specified time, ODE numerical integration is terminated, and obtains initial value of the current solution as Newton iteration It is sent into Newton iteration device and carries out Newton iteration;
5) if coverage changes with time rate less than convergence precision, iteration is terminated, steady state solution is obtained and carries out step 6), if It is not converged, then return step 3) starting point of ODE numerical integration algorithm is used as using current solution, continue ODE numerical integration, and repeatedly Step 3) -5);
6) catalyst system reaction rate is obtained according to steady state solution.
2. the heterogeneous catalysis surface coverage of a kind of combination ODE integral according to claim 1 and Newton iterative method obtains Method, which is characterized in that in the step 2), micro kinetics steady-state equation are as follows:
Wherein,For adsorbate AnCoverage on surface,For adsorbate AnCoefficient in elementary reaction e, reFor primitive The reaction rate of reaction.
3. the heterogeneous catalysis surface coverage of a kind of combination ODE integral according to claim 1 and Newton iterative method obtains Method, which is characterized in that the convergence precision in the step 5) is 10e-50.
4. the heterogeneous catalysis surface coverage of a kind of combination ODE integral according to claim 1 and Newton iterative method obtains Method, which is characterized in that in the step 4), the wherein time span and time step of ODE numerical integration, with hydridization iteration It automatically adjusts, then has:
α × 10 T=N
I=10-(N+2)
Wherein, T is the time span of integral, and I is time step, and α is an adjustable value, and for size between 0~1, N is to work as The number of preceding hydridization iteration.
5. the heterogeneous catalysis surface coverage of a kind of combination ODE integral according to claim 1 and Newton iterative method obtains Method, which is characterized in that in the step 3), ODE numerical integration algorithm uses real value variable coefficient ODE Integration Solving device.
6. the heterogeneous catalysis surface coverage of a kind of combination ODE integral according to claim 1 and Newton iterative method obtains Method, which is characterized in that the step 4) specifically includes the following steps:
41) using the solution of ODE numerical integration as initial coverage Θ0
42) iteration direction d is obtained:
43) by iterative rate constant λ=0.5i-1As iteration step length, wherein i is the step number of current Newton iteration;
44) after obtaining iteration direction and step-length, pass through Θi+1i+ λ d updates coverage;
45) iteration is terminated when iteration convergence, otherwise return step 42) until convergence.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111488550A (en) * 2020-03-18 2020-08-04 华东理工大学 Method for efficiently solving steady-state micro-dynamics equation set based on automatic combination of time integration and Newton method

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101260037A (en) * 2008-03-17 2008-09-10 华东理工大学 Modeling method for alkylarene liquid phase oxidation dynamics mechanism model
CN101763087A (en) * 2009-12-29 2010-06-30 浙江大学 Industrial process dynamic optimization system and method based on nonlinear conjugate gradient method
CN101776892A (en) * 2009-12-31 2010-07-14 浙江大学 Constraint-prioritized dynamic industrial process optimization system and method
US8577947B2 (en) * 2009-03-17 2013-11-05 Kunsan National University Industry-Academic Cooperation Foundation Method of finding solution of equation and recording medium storing program for implementing the same
US20140088936A1 (en) * 2012-09-25 2014-03-27 Dow Global Technologies Llc Catalytic zones in continuous catalytic reactors
CN105701267A (en) * 2015-05-13 2016-06-22 青岛科技大学 Method for modelling oil catalytic cracking reaction regeneration part
CN106483496A (en) * 2016-10-19 2017-03-08 河南城建学院 Based on CHAN algorithm with improve Newton iteration combine time difference positioning method
CN108717265A (en) * 2018-05-30 2018-10-30 重庆邮电大学 A kind of unmanned vehicle cruise tracking control system and control method based on control variable parameter
CN108717176A (en) * 2018-04-12 2018-10-30 哈尔滨工程大学 Time difference locating technology method based on artificial bee colony algorithm
CN109002681A (en) * 2018-05-25 2018-12-14 胡培君 Simulation/prediction surface catalysis reacting middle catalyst catalytic activity method and its application
CN109192250A (en) * 2018-08-01 2019-01-11 华东理工大学 The speeding-up simulation method of surface species fast transferring is overcome in a kind of heterogeneous catalysis

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101260037A (en) * 2008-03-17 2008-09-10 华东理工大学 Modeling method for alkylarene liquid phase oxidation dynamics mechanism model
US8577947B2 (en) * 2009-03-17 2013-11-05 Kunsan National University Industry-Academic Cooperation Foundation Method of finding solution of equation and recording medium storing program for implementing the same
CN101763087A (en) * 2009-12-29 2010-06-30 浙江大学 Industrial process dynamic optimization system and method based on nonlinear conjugate gradient method
CN101776892A (en) * 2009-12-31 2010-07-14 浙江大学 Constraint-prioritized dynamic industrial process optimization system and method
US20140088936A1 (en) * 2012-09-25 2014-03-27 Dow Global Technologies Llc Catalytic zones in continuous catalytic reactors
CN105701267A (en) * 2015-05-13 2016-06-22 青岛科技大学 Method for modelling oil catalytic cracking reaction regeneration part
CN106483496A (en) * 2016-10-19 2017-03-08 河南城建学院 Based on CHAN algorithm with improve Newton iteration combine time difference positioning method
CN108717176A (en) * 2018-04-12 2018-10-30 哈尔滨工程大学 Time difference locating technology method based on artificial bee colony algorithm
CN109002681A (en) * 2018-05-25 2018-12-14 胡培君 Simulation/prediction surface catalysis reacting middle catalyst catalytic activity method and its application
CN108717265A (en) * 2018-05-30 2018-10-30 重庆邮电大学 A kind of unmanned vehicle cruise tracking control system and control method based on control variable parameter
CN109192250A (en) * 2018-08-01 2019-01-11 华东理工大学 The speeding-up simulation method of surface species fast transferring is overcome in a kind of heterogeneous catalysis

Non-Patent Citations (7)

* Cited by examiner, † Cited by third party
Title
CHEN JIAN-FU ET AL: "Reversibility Iteration Method for Understanding Reaction Networks and for Solving Microkinetics in Heterogeneous Catalysis", 《ACS CATALYSIS》 *
JOSEP FONT ET AL: "Testing a predictor-corrector integral method for estimating parameters in complex kinetic systems described by ordinary differential equations", 《COMPUTERS & CHEMICAL ENGINEERING》 *
PEDRO A.SAA ET AL: "Formulation, construction and analysis of kinetic models of metabolism: A review of modelling frameworks", 《BIOTECHNOLOGY ADVANCES》 *
侯卫锋: "催化重整流程模拟与优化技术及其应用研究", 《中国博士学位论文全文数据库电子期刊 工程科技I辑》 *
胡永有: "催化重整流程模拟及优化研究", 《中国博士学位论文全文数据库电子期刊 信息科技辑》 *
邓振淼: "正弦波频率估计的牛顿迭代方法初始值研究", 《电子学报》 *
郑瑾环: "非线性常微分方程初值问题的样条函数迭代法", 《云南师范大学学报》 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111488550A (en) * 2020-03-18 2020-08-04 华东理工大学 Method for efficiently solving steady-state micro-dynamics equation set based on automatic combination of time integration and Newton method
CN111488550B (en) * 2020-03-18 2023-06-16 华东理工大学 Method for efficiently solving steady-state micro-dynamics equation set based on automatic combination of time integral and Newton method

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