Wood pyrolysis simulation method based on Fluent-UDF

Abstract

The invention discloses a wood pyrolysis simulation method based on Fluent-UDF, and belongs to the technical field of energy utilization, and the method comprises the following steps: carrying out wood thermogravimetry, TG-DSC analysis, extraction of pyrolysis data characteristics, solving of a pyrolysis rate and a heat absorption and release calculation formula, and implantation in the Fluent-UDF to form a pyrolysis process reproduction code; the method comprises the following steps: performing Fluent simulation based on a wood pyrolysis environment, setting a wood area as a porous medium, loading a UDF code, and extracting wood thermogravimetric change simulation data after calculation; performing a wood pyrolysis experiment in the same environment to obtain wood thermogravimetric change data; wood thermogravimetric simulation and experimental data are compared, the wood pyrolysis simulation process is corrected, the wood pyrolysis simulation precision is improved, and therefore high-precision wood pyrolysis process simulation reproduction based on Fluent-UDF is achieved. According to the method, a reproduction method reference based on Fluent-UDF can be provided for wood pyrolysis simulation.

Description

Technical Field

[0001] The invention relates to the technical field of energy utilization, and in particular to a wood pyrolysis simulation method based on Fluent-UDF. Background Art

[0002] In the field of wood processing and utilization, pyrolysis, as an important chemical conversion technology, is widely used in the production of biofuels, chemicals, activated carbon and other products. However, the complexity of the wood pyrolysis process, including its multi-stage reaction mechanism, temperature dependence and interaction with the pore structure, makes it a challenge to accurately predict and control the pyrolysis behavior. Traditional research methods mostly rely on experimental means. Although they can provide direct data support, they have the limitations of high cost, long cycle and difficulty in fully covering all working conditions. Therefore, developing an efficient and accurate numerical simulation method to reproduce the wood pyrolysis process and predict its product distribution is of great significance for optimizing the pyrolysis process and improving resource utilization.

[0003] In recent years, with the rapid development of computational fluid dynamics (CFD) technology, its application in the field of chemical reaction engineering has become increasingly widespread. As a powerful CFD software, Fluent not only has the ability to handle complex flow and heat transfer problems, but also provides a UDF interface, allowing users to write custom codes according to specific needs to achieve numerical simulation of complex physical and chemical processes. In the simulation of wood pyrolysis, by treating wood as a porous medium, combining the pyrolysis rate calculation formula and UDF technology, a detailed description of the temperature distribution, mass transfer and chemical reaction kinetics inside the wood can be achieved. However, most of the current research on wood pyrolysis simulation focuses on a single factor or a simplified model, lacking a comprehensive consideration of the coupling of multiple factors in the pyrolysis process, resulting in limited simulation accuracy. Therefore, in-depth research on the wood pyrolysis mechanism and the development of a high-precision pyrolysis simulation method based on Fluent-UDF are of great significance to improving the scientificity and practicality of wood pyrolysis technology.

[0004] In the practical application of wood pyrolysis technology, accurate prediction and control of key parameters in the pyrolysis process, such as temperature, pressure, residence time, etc., are crucial to optimizing product quality and improving production efficiency. However, since wood pyrolysis involves multiple chemical reactions and physical processes, and the processes influence each other, traditional experimental methods are difficult to fully reveal its internal mechanism. In addition, the experimental process is also interfered by a variety of external factors, such as equipment accuracy and operating conditions, which further increases the uncertainty of the experimental results. In contrast, the numerical simulation method has the advantages of low cost, short cycle, and good repeatability. It can simulate the entire process of wood pyrolysis in a virtual environment, providing strong support for experimental research and process optimization. Therefore, combined with Fluent-UDF technology, the development of a numerical simulation method that can accurately reproduce the wood pyrolysis process and predict its product distribution will not only help to deepen the understanding of the wood pyrolysis mechanism, but also provide a powerful tool for technological innovation in the field of wood processing and utilization. Summary of the invention

[0005] The present invention provides a wood pyrolysis simulation method based on Fluent-UDF. Through thermogravimetric analysis of wood, pyrolysis data features are extracted, a pyrolysis rate calculation formula is solved, and a pyrolysis process reproduction code is implanted in Fluent-UDF; Fluent simulation is performed based on the wood pyrolysis environment, the wood area is set as a porous medium, the UDF code is loaded, and the wood thermogravimetric change simulation data is extracted after calculation; wood pyrolysis experiments are performed under the same environment to obtain wood thermogravimetric experimental data; the wood thermogravimetric simulation and experimental data are compared, the wood pyrolysis simulation process is corrected, and the accuracy of wood pyrolysis simulation is improved, thereby realizing a high-precision simulation reproduction of the wood pyrolysis process based on Fluent-UDF. The present invention can provide a reproduction method reference based on Fluent-UDF for wood pyrolysis simulation, so as to solve the technical problem that the numerical prediction accuracy of the wood pyrolysis process is not high.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] In one aspect, the present invention provides a wood pyrolysis simulation method based on Fluent-UDF, and the wood pyrolysis simulation method based on Fluent-UDF comprises:

[0008] Conduct thermogravimetric and TG-DSC analysis of wood, extract pyrolysis data characteristics, solve pyrolysis rate and heat absorption and release calculation formulas, and embed them into Fluent-UDF to form pyrolysis process reproduction code;

[0009] Fluent simulation is performed based on the wood pyrolysis environment. The wood area is set as a porous medium, the UDF code is loaded, and the thermogravimetric change simulation data of the wood is extracted after calculation.

[0010] Carry out wood pyrolysis experiments under the same environment to obtain wood thermogravimetric change data;

[0011] By comparing the thermogravimetric simulation of wood with the experimental data, the wood pyrolysis simulation process was corrected and the accuracy of the wood pyrolysis simulation was improved, thus achieving a high-precision simulation and reproduction of the wood pyrolysis process based on Fluent-UDF.

[0012] Furthermore, thermogravimetric and TG-DSC analysis of wood was performed to extract the characteristics of pyrolysis data, including:

[0013] Select representative wood samples to ensure that their species, moisture content, density and other physical properties meet the research requirements;

[0014] The programmed temperature pyrolysis experiment of wood samples was carried out using a high-precision thermogravimetric analyzer and TG-DSC analyzer;

[0015] During the experiment, the detailed data of wood quality and heat absorption and release as a function of temperature were recorded, including key parameters such as the initial pyrolysis temperature, the temperature of the maximum weight loss rate, and the final pyrolysis temperature;

[0016] Through in-depth analysis of pyrolysis data, the main data characteristics of the wood pyrolysis process are extracted, such as the shape of the pyrolysis curve, the changing trend of the weight loss rate, and the pyrolysis behavior patterns in different temperature ranges.

[0017] Furthermore, the pyrolysis rate and heat absorption and release calculation formulas are solved, including:

[0018] Based on the extracted pyrolysis data characteristics, mathematical methods (such as differential method, curve fitting, etc.) are used to solve the calculation formulas for wood pyrolysis rate and heat absorption and release;

[0019] This formula should be able to accurately describe the rate at which wood mass changes with temperature, including the slow weight loss in the initial stage, the rapid weight loss during the main pyrolysis stage, and the subsequent slow change stage;

[0020] In order to improve the universality and accuracy of the formula, it is possible to consider introducing multiple variables (such as temperature, heating rate, wood type, etc.) as parameters, and determine the optimal value of each parameter through methods such as multiple regression analysis.

[0021] Furthermore, the pyrolysis process reproduction code is implanted into Fluent-UDF, including:

[0022] The solved pyrolysis rate and heat absorption and release calculation formulas are implanted into Fluent's UDF environment, and the corresponding UDF code is written to simulate the pyrolysis process of wood;

[0023] In the UDF code, it is necessary to define the porous media model of wood, including the settings of physical properties such as porosity, permeability, and thermal conductivity;

[0024] At the same time, a code was written to calculate the wood mass change, temperature distribution, and gas product generation based on the pyrolysis rate formula;

[0025] In order to ensure good compatibility and efficient operation of the UDF code with the Fluent software, code optimization and debugging are also required, such as adjusting the solver settings, optimizing the mesh division, and ensuring the correctness of data transmission.

[0026] Furthermore, Fluent simulation is performed based on the wood pyrolysis environment, including:

[0027] Set the boundary conditions and initial conditions for wood pyrolysis simulation in Fluent, such as temperature field, air flow velocity, boundary heat exchange, etc.;

[0028] Set the wood area as porous media and load the written UDF code;

[0029] Through the Fluent solver, numerical simulation is performed to calculate the thermogravimetric change, heat absorption and release, temperature distribution, gas flow, product generation and other parameters of wood under specific pyrolysis environment;

[0030] During the simulation process, the solution strategy and parameter settings are adjusted in a timely manner based on the stability and convergence of the solution.

[0031] Furthermore, the simulation data of thermogravimetric changes of wood are extracted, including:

[0032] After the simulation is completed, the simulation data of the thermogravimetric change of wood is extracted from the result file of Fluent;

[0033] These data include the mass, temperature, and concentration distribution of gas products of the wood at different time points;

[0034] Through data processing and analysis, a simulation curve of the thermogravimetric change of wood was drawn and compared with the theoretical prediction to evaluate the accuracy and reliability of the simulation results.

[0035] Furthermore, wood pyrolysis experiments were conducted under the same environment, including:

[0036] Pyrolysis experiments were conducted using the same wood samples as in the simulations under the same experimental conditions;

[0037] During the experiment, parameters such as temperature and air flow velocity must be strictly controlled to ensure that the experimental conditions are consistent with the simulated environment;

[0038] Use an electronic balance or other appropriate experimental equipment to record the mass change data during the wood pyrolysis process, and record the phenomena and observations during the experiment in detail.

[0039] Furthermore, the thermogravimetric simulation and experimental data of wood are compared, including:

[0040] The extracted simulation data were compared and analyzed with the experimental data to evaluate the differences and consistency between the two;

[0041] By comparing the shape of thermogravimetric curves, the value and trend of weight loss rate, etc., possible deviations and error sources in the simulation process can be identified;

[0042] In response to these deviations, the causes are analyzed and corresponding improvement measures are proposed, such as adjusting the parameter settings in the UDF code and optimizing the porous media model.

[0043] Furthermore, the wood pyrolysis simulation process was modified to improve the simulation accuracy, including:

[0044] According to the results of comparative analysis, the wood pyrolysis simulation process is modified and optimized;

[0045] This includes adjusting the pyrolysis rate calculation formula in the UDF code, optimizing the physical parameters of the porous media model, and improving the solution strategy;

[0046] Through multiple iterations and verifications, the difference between simulation data and experimental data is gradually reduced, and the accuracy and reliability of wood pyrolysis simulation are improved.

[0047] Furthermore, a high-precision simulation of the wood pyrolysis process based on Fluent-UDF is achieved, including:

[0048] After correction and optimization, the simulation and reproduction of wood pyrolysis process with high accuracy based on Fluent-UDF was finally achieved;

[0049] The simulation system can accurately predict the thermogravimetric changes, temperature distribution, and gas product generation of wood under different pyrolysis conditions, providing strong support for the design and optimization of wood pyrolysis processes.

[0050] At the same time, the simulation system can also be used for scientific research in areas such as studying the physical and chemical mechanisms of wood pyrolysis and exploring new pyrolysis technologies.

[0051] Based on the thermogravimetric analysis of wood and the results of pyrolysis experiments, the present invention proposes a method for simulating and reproducing the pyrolysis process of wood based on Fluent-UDF, which can reproduce the pyrolysis process of wood with high accuracy, thereby providing a reference for the pyrolysis reproduction method of wood based on Fluent-UDF for the field of energy utilization technology.

[0052] Compared with the prior art, the technical solution provided by the present invention has at least the following beneficial effects:

[0053] 1. Through in-depth analysis of the characteristics of wood pyrolysis data, the accurate pyrolysis rate calculation formula is solved, and it is implanted into Fluent-UDF to form a reproducible code, so that the simulation process can more accurately reflect the actual behavior of wood pyrolysis. This refined simulation method overcomes the shortcomings of traditional simplified models in prediction accuracy and improves the reliability and accuracy of simulation results. Compared with traditional experimental research methods, numerical simulation methods have the advantages of low cost and short cycle. Through numerical simulation, the wood pyrolysis process under different working conditions can be quickly simulated in a virtual environment, avoiding the high equipment cost, time-consuming experimental cycle and possible experimental errors in experimental research. This not only improves research efficiency, but also reduces research costs.

[0054] 2. The simulation method based on Fluent-UDF allows users to customize models and parameters according to specific needs, and has strong flexibility and scalability. Users can adjust model parameters according to factors such as wood type and pyrolysis conditions to meet different research needs. In addition, with the deepening of understanding of the wood pyrolysis mechanism and the accumulation of experimental data, the simulation model can be continuously optimized and improved. The high-precision wood pyrolysis simulation method provides strong support for technological innovation and process optimization. By simulating the pyrolysis process under different process conditions, the product quality and output can be predicted, the feasibility of the process scheme can be evaluated, and a scientific basis can be provided for process optimization. At the same time, the simulation results can also provide theoretical guidance and data support for the development of new pyrolysis technologies, catalysts and reactors, and promote technological progress in the field of wood processing and utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0056] Figure 1 It is a schematic diagram of the execution flow of the wood pyrolysis simulation method based on Fluent-UDF provided in an embodiment of the present invention;

[0057] Figure 2 It is a schematic diagram of the Fluent-UDF execution process provided by an embodiment of the present invention;

[0058] Figure 3 It is a schematic diagram of a simulation calculation domain and a grid provided by an embodiment of the present invention;

[0059] Figure 4 is a schematic diagram of a wood block ignition experiment provided by an embodiment of the present invention;

[0060] Figure 5 It is a comparison chart between the thermogravimetric simulation results and the experimental results provided in the embodiment of the present invention. DETAILED DESCRIPTION

[0061] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0062] First of all, it should be noted that in the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplary" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the word "exemplarily" is intended to present the concept in a concrete way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or it can be either of the two.

[0063] Moreover, in the embodiments of the present invention, "image" and "picture" can sometimes be used interchangeably. It should be noted that when the difference between them is not emphasized, the meanings they want to express are the same. "of", "corresponding, relevant" and "corresponding" can sometimes be used interchangeably. It should be noted that when the difference between them is not emphasized, the meanings they want to express are the same.

[0064] In addition, in the embodiments of the present invention, sometimes a subscript (such as W1) may be mistakenly written as a non-subscript form (such as W1). When the difference is not emphasized, the meanings to be expressed are consistent.

[0065] Example

[0066] This embodiment provides a wood pyrolysis simulation method based on Fluent-UDF, which can be implemented by an electronic device, which can be a terminal or a server. The execution flow of the wood pyrolysis simulation method based on Fluent-UDF is shown in the figure, including:

[0067] S1, conduct thermogravimetric and TG-DSC analysis of wood and extract characteristics of pyrolysis data;

[0068] Specifically, in this embodiment, the implementation process of the above S1 is as follows:

[0069] S11, select representative wood samples to ensure that their physical properties such as species, moisture content, density, etc. meet the research requirements;

[0070] S12, using a high-precision thermogravimetric analyzer and TG-DSC analyzer to perform a programmed temperature pyrolysis experiment on wood samples, during which detailed data on wood mass, heat absorption and release as a function of temperature and time were recorded, including key parameters such as the initial pyrolysis temperature, the temperature of the maximum weight loss rate, and the final pyrolysis temperature;

[0071] S13, in-depth analysis of experimental data, extracting the main data characteristics of wood pyrolysis process, such as the shape of pyrolysis curve, the changing trend of weight loss rate and pyrolysis behavior pattern in different temperature ranges.

[0072] S2, solve the formula for calculating the pyrolysis rate and heat absorption and release;

[0073] Specifically, in this embodiment, the implementation process of the above S2 is as follows:

[0074] S21, based on the extracted pyrolysis data characteristics, mathematical methods (such as differential method, curve fitting, etc.) are used to solve the calculation formula of wood pyrolysis rate and heat absorption and release. The formula should be able to accurately describe the pyrolysis rate and heat absorption and release of wood mass as it changes with temperature, including the slow weight loss in the initial stage, the rapid weight loss in the main pyrolysis stage, and the subsequent slow change stage;

[0075] S22, introduce multiple variables (such as temperature, heating rate, wood type, etc.) as parameters, and determine the optimal value of each parameter through methods such as multiple regression analysis.

[0076] S3, implant the pyrolysis rate and heat absorption and release calculation formula into Fluent-UDF to form the pyrolysis process reproduction code;

[0077] Specifically, in this embodiment, the implementation process of the above S3 is as follows:

[0078] S31, implant the solved pyrolysis rate and heat absorption and release calculation formulas into the UDF environment of Fluent, and write corresponding UDF codes to simulate the pyrolysis process of wood;

[0079] S32, in the UDF code, defines the porous media model of wood, including the settings of physical properties such as porosity, permeability, and thermal conductivity;

[0080] S33, write the code to calculate the change of wood mass, temperature distribution and gas product generation according to the pyrolysis rate formula, and perform code optimization and debugging, such as adjusting the solver settings, optimizing the grid division, ensuring the correctness of data transmission, etc.

[0081] S4, Fluent simulation based on wood pyrolysis environment;

[0082] Specifically, in this embodiment, the implementation process of the above S4 is as follows:

[0083] S41, set the boundary conditions and initial conditions for wood pyrolysis simulation in Fluent, such as temperature field, air flow velocity, boundary heat exchange, etc.;

[0084] S42, setting the wood area as porous medium and loading the written UDF code;

[0085] S43, through the Fluent solver, numerical simulation is performed to calculate the thermogravimetric changes, heat absorption and release, temperature distribution, gas flow, product generation and other parameters of wood under a specific pyrolysis environment. During the simulation process, the solution strategy and parameter settings are adjusted in a timely manner based on the stability and convergence of the solution.

[0086] S5, extracting the simulated data of thermogravimetric changes of wood;

[0087] Specifically, in this embodiment, the implementation process of the above S5 is as follows:

[0088] S51, after the simulation is completed, the simulation data of the thermogravimetric change of the wood is extracted from the result file of Fluent, which includes the mass, temperature and concentration distribution of the gas products of the wood at different time points;

[0089] S52, through data processing and analysis, draw the simulation curve of wood thermogravimetric change and compare it with the theoretical prediction to evaluate the accuracy and reliability of the simulation results.

[0090] S6, conducting wood pyrolysis experiments under the same environment to obtain thermogravimetric change data of the wood;

[0091] Specifically, in this embodiment, the implementation process of the above S6 is as follows:

[0092] S61, under the same experimental conditions, the same wood samples as in the simulation were used for pyrolysis experiments. The temperature, air flow velocity and other parameters must be strictly controlled during the experiment to ensure that the experimental conditions are consistent with the simulation environment;

[0093] S62. Use an electronic balance or other appropriate experimental equipment to record the mass change data during the pyrolysis of wood, and record the phenomena and observations during the experiment in detail.

[0094] S7, compare the thermogravimetric simulation of wood with the experimental data, correct the simulation process of wood pyrolysis, and improve the simulation accuracy;

[0095] Specifically, in this embodiment, the implementation process of the above S7 is as follows: S71, compare and analyze the extracted simulation data with the experimental data to evaluate the differences and consistency between the two, and identify possible deviations and error sources in the simulation process by comparing the shapes of the thermogravimetric curves, the values ​​of the weight loss rates and their changing trends; S72, based on the results of comparative analysis, the wood pyrolysis simulation process was modified and optimized, including adjusting the pyrolysis rate calculation formula in the UDF code, optimizing the physical parameters of the porous media model, and improving the solution strategy; S73, through multiple iterations and verifications, the difference between simulation data and experimental data is gradually reduced, and the accuracy and reliability of wood pyrolysis simulation are improved. Below, this embodiment uses a practical application scenario to illustrate the application process of the method of the present invention.

[0104] In this example, Finnish pine was used as the wood sample, and the Fluent-UDF wood pyrolysis simulation process was reproduced based on thermogravimetric analysis and ignition experimental thermogravimetric data. The ambient temperature of this example was 14°C, and a square oil pan of n-heptane was used as the ignition source in an open space. The side length of the oil pan was 30 cm and the height of the oil pan was 5 cm. Based on this, the specific implementation process of the method of the present invention is as follows:

[0105] (1) Thermogravimetric analysis of Finnish pine sawdust.

[0106] The programmed temperature pyrolysis experiment of Finnish pine sawdust samples was carried out using a high-precision thermogravimetric analyzer and a TG-DSC analyzer. The temperature range was from room temperature to 1073K (800℃), the heating rates were set to 5K / min and 10K / min, respectively, and a N2 atmosphere with a flow rate of 30mL / min was used.

[0107] The data on wood quality and heat absorption and release as a function of temperature were recorded in detail, including key parameters such as the initial pyrolysis temperature, the temperature of maximum weight loss rate, and the final pyrolysis temperature. The pyrolysis data were deeply analyzed to extract the main data characteristics of the wood pyrolysis process, such as the shape of the pyrolysis curve, the changing trend of the weight loss rate, and the pyrolysis behavior patterns in different temperature ranges. The experimental data were converted into conversion rate, the relationship curve between conversion rate and temperature and time, and the relationship curve between heat absorption and release and conversion rate.

[0108] (2) Solve the pyrolysis rate and heat absorption and release calculation formulas, and implant them into Fluent-UDF to form the pyrolysis process reproduction code.

[0109] The pyrolysis rate of the thermogravimetric analysis data was calculated based on the Arrhenius formula, and the relationship curves between the apparent activation energy, the frequency factor and the product of the mechanism function ln value and the conversion rate were constructed respectively. The above relationship curves and the relationship curve between the heat absorption and release and the conversion rate were fitted using piecewise polynomials to facilitate implantation;

[0110] The solved pyrolysis rate and heat absorption and release calculation formulas are implanted into Fluent's UDF environment, and the corresponding UDF code is written to simulate the pyrolysis process of wood. In the UDF code, the porous medium model of wood is defined, including the settings of physical properties such as porosity, permeability, and thermal conductivity. At the same time, the code for calculating the change in wood mass, temperature distribution, and gas product generation is written and optimized and debugged. Its operating logic is as follows: Figure 2 shown.

[0111] (3) Based on Fluent, the pyrolysis simulation of the ignition process of Finnish pine wood blocks was carried out to extract the simulation data of the thermogravimetric changes of the wood blocks.

[0112] In Fluent, the boundary conditions and initial conditions of wood pyrolysis simulation are set, such as temperature field, air flow velocity, boundary heat exchange, etc. The calculation domain and grid diagram are shown in the figure. Figure 3 As shown in the figure, the wood area is set as a porous medium, and the written UDF code is loaded. The ignition simulation of the Finnish pine block is carried out through the Fluent solver. The thermogravimetric change, heat absorption and release, temperature distribution, gas flow and product generation parameters of the wood under this specific pyrolysis environment are calculated. According to the stability and convergence of the solution, the solution strategy and parameter settings are adjusted in time.

[0113] After the simulation is completed, the simulation data of the thermogravimetric changes of wood are extracted from the Fluent result file, including the mass, temperature and concentration distribution of gas products of wood at different time points. Through data processing and analysis, the simulation curve of the thermogravimetric changes of wood is drawn and compared with the theoretical prediction to evaluate the accuracy and reliability of the simulation results.

[0114] (4) Conduct an ignition experiment on Finnish pine wood blocks under the same environment, compare the simulation data with the experimental data, and correct the simulation process.

[0115] Under the same experimental conditions, the ignition experiment was carried out using the same wood block size and shape as in the simulation. The ignition scenario is as follows: Figure 4 As shown, the temperature and other environmental parameters must be strictly controlled during the experiment to ensure that the experimental conditions are consistent with the simulated environment. An electronic balance is used to record the mass change data of the wood block during ignition, and the phenomena and observations during the experiment are recorded in detail.

[0116] Compare and analyze the extracted simulation data with the experimental data to evaluate the differences and consistency between the two. By comparing the shape of the thermogravimetric curve, the value and trend of the weight loss rate, etc., possible deviations and error sources in the simulation process can be identified;

[0117] According to the results of comparative analysis, the wood pyrolysis simulation process was modified and optimized, including adjusting the pyrolysis rate calculation formula in the UDF code, optimizing the physical parameters of the porous medium model, improving the solution strategy, etc. Through multiple iterations and verifications, the difference between the simulation data and the experimental data was gradually reduced, and the accuracy and reliability of the wood pyrolysis simulation were improved. Finally, the thermogravimetric simulation of the wood block was compared with the experiment. Figure 5 shown.

[0118] In summary, this embodiment provides a method for simulating wood pyrolysis based on Fluent-UDF, which performs thermogravimetric analysis of wood, extracts pyrolysis data features, solves the pyrolysis rate calculation formula, and implants the pyrolysis process reproduction code in Fluent-UDF; performs Fluent simulation based on the wood pyrolysis environment, sets the wood area as a porous medium, loads the UDF code, and extracts the thermogravimetric change simulation data of the wood after calculation; performs wood pyrolysis experiments under the same environment, and obtains wood thermogravimetric experimental data; compares wood thermogravimetric simulation and experimental data, corrects the wood pyrolysis simulation process, and improves the accuracy of wood pyrolysis simulation, thereby achieving high-precision simulation and reproduction of wood pyrolysis process based on Fluent-UDF. The present invention can provide a reference for a reproduction method based on Fluent-UDF for wood pyrolysis simulation.

[0119] Finally, it should be noted that the above is a preferred embodiment of the present invention. It should be noted that although the basic creative concept of the present invention has been described, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention. Therefore, the attached claims are intended to be interpreted as including the preferred embodiment and all changes and modifications that fall within the scope of the embodiments of the present invention.

Claims

1. A wood pyrolysis simulation method based on Fluent-UDF, characterized in that: The wood pyrolysis simulation method based on Fluent-UDF includes: Conduct thermogravimetric and TG-DSC analysis of wood, extract pyrolysis data features, solve the pyrolysis rate calculation formula, and embed it into Fluent-UDF to form a pyrolysis process reproduction code; Fluent simulation is performed based on the wood pyrolysis environment. The wood area is set as a porous medium, the UDF code is loaded, and the thermogravimetric change simulation data of the wood is extracted after calculation. Carry out wood pyrolysis experiments under the same environment to obtain wood thermogravimetric change data; By comparing the thermogravimetric simulation of wood with the experimental data, the wood pyrolysis simulation process was corrected and the accuracy of the wood pyrolysis simulation was improved, thus achieving a high-precision simulation and reproduction of the wood pyrolysis process based on Fluent-UDF.

2. The wood pyrolysis simulation method based on Fluent-UDF according to claim 1, characterized in that: Conduct wood thermogravimetric and TG-DSC analysis to extract pyrolysis data features, including: Select representative wood samples to ensure that their species, moisture content, density and other physical properties meet the research requirements; The programmed temperature pyrolysis experiment of wood samples was carried out using a high-precision thermogravimetric analyzer and TG-DSC analyzer; During the experiment, the detailed data of wood quality and heat absorption and release as a function of temperature were recorded, including key parameters such as the initial pyrolysis temperature, the temperature of the maximum weight loss rate, and the final pyrolysis temperature; Through in-depth analysis of pyrolysis data, the main data characteristics of the wood pyrolysis process are extracted, such as the shape of the pyrolysis curve, the changing trend of the weight loss rate, and the pyrolysis behavior patterns in different temperature ranges.

3. The wood pyrolysis simulation method based on Fluent-UDF according to claim 1, characterized in that: Solve the pyrolysis rate and heat absorption and release calculation formulas, including: Based on the extracted pyrolysis data characteristics, mathematical methods (such as differential method, curve fitting, etc.) are used to solve the calculation formulas for wood pyrolysis rate and heat absorption and release; This formula should be able to accurately describe the rate at which wood mass, heat absorption and release change with temperature, including the slow weight loss in the initial stage, the rapid weight loss in the main pyrolysis stage, and the subsequent slow change stage; In order to improve the universality and accuracy of the formula, it is possible to consider introducing multiple variables (such as temperature, heating rate, wood type, etc.) as parameters, and determine the optimal value of each parameter through methods such as multiple regression analysis.

4. The wood pyrolysis simulation method based on Fluent-UDF according to claim 1, characterized in that: The pyrolysis process reproduction code is implanted into Fluent-UDF, including: The pyrolysis rate calculation formula obtained by solving the problem is implanted into Fluent's UDF environment, and the corresponding UDF code is written to simulate the pyrolysis process of wood; In the UDF code, it is necessary to define the porous media model of wood, including the settings of physical properties such as porosity, permeability, and thermal conductivity; At the same time, a code was written to calculate the change in wood mass, heat absorption and release, temperature distribution, and gas product generation based on the pyrolysis rate formula; In order to ensure good compatibility and efficient operation of the UDF code with the Fluent software, code optimization and debugging are also required, such as adjusting the solver settings, optimizing the mesh division, and ensuring the correctness of data transmission.

5. The wood pyrolysis simulation method based on Fluent-UDF according to claim 1, characterized in that: Fluent simulation based on wood pyrolysis environment, including: Set the boundary conditions and initial conditions for wood pyrolysis simulation in Fluent, such as temperature field, air flow velocity, boundary heat exchange, etc.; Set the wood area as porous media and load the written UDF code; Through the Fluent solver, numerical simulation is performed to calculate the thermogravimetric change, heat absorption and release, temperature distribution, gas flow, product generation and other parameters of wood under specific pyrolysis environment; During the simulation process, the solution strategy and parameter settings are adjusted in a timely manner based on the stability and convergence of the solution.

6. The wood pyrolysis simulation method based on Fluent-UDF according to claim 1, characterized in that: Extract wood thermogravimetric change simulation data, including: After the simulation is completed, the simulation data of the thermogravimetric change of wood is extracted from the result file of Fluent; These data include the mass, temperature and concentration distribution of gas products of the wood at different time points; Through data processing and analysis, a simulation curve of the thermogravimetric change of wood was drawn and compared with the theoretical prediction to evaluate the accuracy and reliability of the simulation results.

7. The wood pyrolysis simulation method based on Fluent-UDF according to claim 1, characterized in that: Carry out wood pyrolysis experiments under the same environment to obtain wood thermogravimetric change data, including: Pyrolysis experiments were conducted using the same wood samples as in the simulations under the same experimental conditions; During the experiment, parameters such as temperature and air flow velocity must be strictly controlled to ensure that the experimental conditions are consistent with the simulated environment; Use an electronic balance or other appropriate experimental equipment to record the mass change data during the wood pyrolysis process, and record the phenomena and observations during the experiment in detail.

8. The wood pyrolysis simulation method based on Fluent-UDF according to claim 1, characterized in that: Compare wood thermogravimetric simulations and experimental data, including: The extracted simulation data were compared and analyzed with the experimental data to evaluate the differences and consistency between the two; By comparing the shape of thermogravimetric curves, the value and trend of weight loss rate, etc., possible deviations and error sources in the simulation process can be identified; In response to these deviations, the causes are analyzed and corresponding improvement measures are proposed, such as adjusting the parameter settings in the UDF code and optimizing the porous media model.

9. The wood pyrolysis simulation method based on Fluent-UDF according to claim 1, characterized in that: Modify the wood pyrolysis simulation process, improve the simulation accuracy, and achieve high-precision wood pyrolysis process simulation reproduction based on Fluent-UDF, including: According to the results of comparative analysis, the wood pyrolysis simulation process is modified and optimized; This includes adjusting the pyrolysis rate calculation formula in the UDF code, optimizing the physical parameters of the porous media model, and improving the solution strategy; Through multiple iterations and verifications, the difference between simulation data and experimental data is gradually reduced, and the accuracy and reliability of wood pyrolysis simulation are improved. After correction and optimization, a high-precision simulation of the wood pyrolysis process based on Fluent-UDF was finally achieved. The simulation system can accurately predict the thermogravimetric changes, temperature distribution, and gas product generation of wood under different pyrolysis conditions, providing strong support for the design and optimization of wood pyrolysis processes. At the same time, the simulation system can also be used for scientific research in areas such as studying the physical and chemical mechanisms of wood pyrolysis and exploring new pyrolysis technologies.

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