Method, apparatus, device and storage medium for decoking the inner wall of a tubular reactor

Abstract

This invention discloses a method, apparatus, equipment, and storage medium for decoking the inner wall of a tubular reactor. The method includes the following steps: generating a corresponding three-dimensional simulation model based on a biomass pyrolysis device; using the three-dimensional simulation model of this invention, the predicted volume fraction distribution of the main solid components and the predicted temperature distribution of the tubular reactor after one time step can be calculated; then, the current flow purging rate of the coking grid and the predicted amount of coke adhesion after one time step are further calculated; thus, it can be determined whether the flow purging rate and jet temperature of the coking grid need to be adjusted in the next long time step. Furthermore, by quantitatively adjusting the flow purging rate or jet temperature of specific jet nozzles, the flow purging rate or jet temperature can be increased in targeted areas with excessive coking, thereby preventing excessive coking on the inner wall of the tubular reactor. This invention can effectively improve the response speed of decoking control on the inner wall of a tubular reactor, thereby improving the control effect of tar removal.

Description

Technical Field

[0001] This invention relates to the field of chemical processes, and in particular to a method, apparatus, equipment, and storage medium for decoking the inner wall of a tubular reactor. Background Technology

[0002] In reactions involving petrochemicals and coal chemicals, coking often occurs on the reactor walls. This coking phenomenon is quite common, and its causes are complex. It is generally believed that due to the different compositions of ash in the raw materials themselves, or due to incomplete recombination and decomposition of the raw materials under reaction conditions, a large amount of coke will adhere to the reactor walls.

[0003] In chemical processes, coking on the reactor wall can lead to a series of negative impacts that restrict the process, such as material blockage inside the reactor, incomplete reaction, and increased operating pressure.

[0004] In existing technologies, multiple reactors are typically used in parallel with a fixed operating cycle, and each reactor is shut down in batches for manual decoking.

[0005] The inventors discovered through research that existing descorching methods have at least the following drawbacks:

[0006] The inability to perform targeted decoking based on the actual coking situation inside the reactor and the need to shut down the reactor for maintenance will affect the normal production activities of the equipment and result in excessive maintenance costs.

[0007] The information disclosed in the background section is intended only to enhance the understanding of the overall background of the present invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0008] The purpose of this invention is to reduce the impact of decoking on the normal production of equipment and reduce maintenance costs.

[0009] This invention provides a method for decoking the inner wall of a tubular reactor, comprising the following steps:

[0010] S11. Generate a corresponding three-dimensional simulation model based on the biomass pyrolysis device and mesh it; the decoking mechanism of the biomass pyrolysis device includes a decoking gas generator and an air inlet duct arranged parallel to the inside of the tubular reactor and close to the upper part of the inner wall; the air inlet duct sprays decoking gas into the inner wall of the tubular reactor through a jet hole provided in the tubular reactor.

[0011] S12. Determine the input parameters of the three-dimensional simulation model, including: material feed rate, material temperature, inert gas inlet rate, volumetric flux of decoking gas, temperature of decoking gas, multiphase flow volume fraction, wall heat flux, wall roughness height, solid phase wall shear force, outlet pressure, and multiphase flow interphase drag force.

[0012] S13. Using a preset time step as the calculation period, obtain the simulation results of the three-dimensional simulation model under steady state according to the input parameters; the simulation results include the predicted volume fraction distribution of the solid phase main component of the tubular reactor after one time step, and the predicted temperature distribution.

[0013] S14. Grids whose predicted volume fraction distribution of the solid main component is greater than a preset fraction threshold are identified as target grids; calculate the free coke adhesion force in the target grid region, as well as the gravity and shear stress on the solid main component in the target grid region.

[0014] S15. Determine whether the angle between the resultant force direction of the target grid in the radial direction of the reactor and the normal direction of the wall tangent and the radial direction of the reactor is greater than 90° based on the adhesion force, gravity and shear stress of the free coke. If so, the target grid is determined as a coking grid.

[0015] S16. Calculate the coke increment of each coking grid after one time step, and calculate the predicted coke adhesion amount after one time step based on the current coke inventory of the coking grid.

[0016] S17. Calculate the gas-solid phase drag, liquid-solid phase drag, and convection diffusion for each of the coking grids after one time step, and record the sum of the three as the flow purging amount after one time step.

[0017] S18. Calculate the predicted coke inventory of the coking grid after one time step by the difference between the predicted coke adhesion amount and the flow purging amount.

[0018] S19. When the predicted coke inventory of the coking grid is greater than the preset coking rate threshold, increase the flow purging amount or jet temperature of the jet hole corresponding to the coking grid according to the preset rule, and return to step S13 as the updated flow purging amount or jet temperature; otherwise, generate the control command of the jet hole to which the coking grid belongs with the current flow purging amount or jet temperature as the target flow purging amount or target jet temperature.

[0019] In another aspect of the invention, a decoking device for the inner wall of a tubular reactor is also provided, comprising:

[0020] Memory, used to store computer programs;

[0021] A processor is used to invoke and execute the computer program to implement the various steps of the decoking method for the inner wall of a tubular reactor as described in any of the preceding claims.

[0022] In another aspect of the present invention, a storage medium is also provided, on which a computer program is stored, which, when executed by a processor, implements the various steps of the decoking method for the inner wall of the tubular reactor as described in any of the preceding claims.

[0023] The decoking device on the inner wall of the tubular reactor includes a computer program stored on a medium. The computer program includes program instructions. When the program instructions are executed by the computer, the computer performs the methods described in the above aspects and achieves the same technical effect.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] This invention generates a corresponding three-dimensional simulation model based on the biomass pyrolysis device. Using this model, the predicted volume fraction distribution of the main solid components and the predicted temperature distribution of the tubular reactor after one time step can be calculated. Then, the current flow purging rate of the coking grid and the predicted amount of coke adhesion after one time step can be further calculated. This allows for the determination of whether the flow purging rate and jet temperature of the coking grid need adjustment in the next long-term step. Furthermore, by quantitatively adjusting the flow purging rate or jet temperature of specific jet nozzles, the flow purging rate or jet temperature can be increased in targeted areas with excessive coking, thereby preventing excessive coking on the inner wall of the tubular reactor.

[0026] As can be seen from the above, the present invention uses a pre-judgment method to adjust the volumetric flux and temperature of the decoking gas nozzle in advance according to different operating conditions, thereby effectively improving the response speed of decoking control on the inner wall of the tubular reactor and thus improving the control effect of tar removal.

[0027] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it according to the contents of the specification, and to make the above and other objects, technical features and advantages of the present invention easier to understand, one or more preferred embodiments are listed below and described in detail with reference to the accompanying drawings. Attached Figure Description

[0028] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a flowchart illustrating the steps of the decoking method for the inner wall of the tubular reactor described in this invention.

[0030] Figure 2 This is a schematic diagram of the biomass pyrolysis device described in this invention;

[0031] Figure 3 This is a schematic diagram of the structure of the decoking device on the inner wall of the tubular reactor described in this invention;

[0032] Figure 4 This is a schematic diagram of the structure of the decoking device on the inner wall of the tubular reactor described in this invention. Detailed Implementation

[0033] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0034] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.

[0035] In this document, the terms "first," "second," etc., are used to distinguish two different elements or parts, and are not used to define specific positions or relative relationships. In other words, in some embodiments, the terms "first," "second," etc., can also be used interchangeably.

[0036] Example 1

[0037] To reduce the impact of coking removal on normal equipment production and lower maintenance costs, such as Figure 1 As shown, an embodiment of the present invention provides a method for decoking the inner wall of a tubular reactor, comprising the following steps:

[0038] S11. Generate a corresponding three-dimensional simulation model based on the biomass pyrolysis device and mesh it;

[0039] like Figure 2As shown, the decoking method for the inner wall of the tubular reactor in this embodiment of the invention is applied to a specific biomass pyrolysis device. The reaction equipment includes a tubular reactor 01, a feeding mechanism, a decoking mechanism, and a heating mechanism 02. Material is conveyed through the tubular reactor 01 by the feeding screw shaft 11 of the feeding mechanism for heating. The blades of the feeding screw shaft 11 are close to the bottom of the tubular reactor 01. The decoking mechanism includes a decoking gas generator 21 and an air inlet duct 22 arranged parallel to the inner wall of the tubular reactor 01. The air inlet duct 22 injects decoking gas into the inner wall of the tubular reactor 01 through a jet nozzle 23 located within the tubular reactor 01. A control device 24 controls an electronic valve 25 on the air inlet duct according to a control command to adjust the air intake rate of the jet nozzle 23.

[0040] In practical applications, a material feed hopper 12 is also required to convey materials to the feed screw shaft 11. Both ends of the tubular reactor 01 are sealed to the material feed hopper 12 and the unloading tower 31, respectively. To prevent gas leakage, the connection between the inlet duct 22 of the decoking gas and the wall of the tubular reactor can be sealed by welding, or, depending on the actual situation, by using flanges or other components for flexible sealing, making the device suitable for more process conditions. Furthermore, in practical applications, multiple branches of the inlet duct 22 can be extended to different lengths above the tubular reactor 01. The purpose of these extensions is to distribute the branches at different positions and areas within the tubular reactor 01. This allows for control of the decoking gas inlet rate (i.e., flow purging rate) and purging area based on the distribution of the branches within the tubular reactor 01.

[0041] The embodiments of the present invention model the biomass pyrolysis device in three-dimensional space; in practical applications, the embodiments of the present invention can use any of the existing heating methods, such as electric heating, microwave heating, plasma heating, laser heating, electron beam heating, or a combination of several of them.

[0042] When the heat source of the tubular reactor is one or a combination of electric heating and electron beam heating, the generated three-dimensional simulation model of the tubular reactor can be a three-dimensional thermodynamic model; when the heat source of the tubular reactor is one or a combination of microwave heating, plasma heating, and laser heating, the generated three-dimensional simulation model of the tubular reactor can be a three-dimensional electromagnetic field model; the embodiments of the present invention can utilize three-dimensional electromagnetic field simulation technology to simulate the temperature distribution data inside the reactor cavity;

[0043] In practical applications, the specific methods for meshing a 3D simulation model can be:

[0044] Let the volume of the tubular reactor in the three-dimensional simulation model be V; and the number of jet nozzles be n.

[0045] Let the feed volume flux of the i-th nozzle be Qv. i The angle is Deg i The temperature is T0 i ;

[0046] The meshed 3D simulation model has d meshes and is stored in a set Data, where the temperature of the i-th mesh is T. i Coking amount is Coke i .

[0047] When microwave heating is used as the heat source for a tubular reactor, the dielectric constant of the material, ε, must also be considered. i ′, dielectric loss is ε″ i The loss tangent is tanδ i .

[0048] It should be noted that the tubular reactor in this embodiment of the invention is a continuously fed reactor. The material to be heated continuously enters the tubular reactor cavity from the reactor inlet and exits from the tubular reactor outlet. The tubular reactor heats the material in the cavity through multiple controllable heat sources set in the cavity, and precisely removes the coke adhering to the wall by injecting decoking gas through multiple controllable jet nozzles set in the cavity.

[0049] Preferably, the jet nozzle in this embodiment of the invention may also be equipped with a wind cap to simultaneously spray decoking gas in multiple different directions.

[0050] In practical applications, the mesh of the three-dimensional simulation model in the embodiments of the present invention can be one or more of tetrahedral mesh, hexahedral mesh, pyramidal mesh, wedge mesh and polyhedral mesh; the calibration method can be one or more of general physics, fluid dynamics, plasma and semiconductor.

[0051] S12. Determine the input parameters of the three-dimensional simulation model, including: material feed rate, material temperature, inert gas inlet rate, volumetric flux of decoking gas, temperature of decoking gas, multiphase flow volume fraction, wall heat flux, wall roughness height, solid phase wall shear force, outlet pressure, and multiphase flow interphase drag force.

[0052] Before simulating and predicting the volume fraction distribution and temperature distribution of the main solid components in a tubular reactor, it is necessary to generate various input parameters for the three-dimensional simulation model.

[0053] The input parameters in this embodiment of the invention may specifically include material feed rate, material temperature, inert protective gas inlet rate, decoking gas volumetric flux, decoking gas temperature, multiphase flow volume fraction, wall heat flux, wall roughness height, solid phase wall shear force, outlet pressure, and multiphase flow interphase drag force.

[0054] The inert protective gas in the embodiments of the present invention may include nitrogen, helium, neon, argon, krypton, and xenon; it may be more preferably nitrogen.

[0055] The decoking gas in the embodiments of the present invention may include carbon dioxide, water vapor, or other gases that can react with and decompose free coke; water vapor is preferred.

[0056] S13. Using a preset time step as the calculation period, obtain the simulation results of the three-dimensional simulation model under steady state according to the input parameters; the simulation results include the predicted volume fraction distribution of the solid phase main component of the tubular reactor after one time step, and the predicted temperature distribution.

[0057] In this embodiment of the invention, the reaction may produce a variety of solid products, so it is necessary to define the main component of the solid phase, namely the free coke that is most closely related to the coke adhering to the wall.

[0058] In this embodiment of the invention, the simulation result of the three-dimensional simulation model calculated based on the input parameters is periodic, that is, a calculation is performed every time step (each calculation is based on the generation of a control command); in practical applications, the value of the time step can be determined according to the actual computing power of the computer and the experience of those skilled in the art, and no specific limitation is made here.

[0059] It should be noted that if microwave heating is used, the predicted electromagnetic field strength needs to be calculated using a three-dimensional simulation model.

[0060] In this embodiment of the invention, the purpose of calculating the simulation results of the three-dimensional simulation model based on the input parameters is to obtain the predicted volume fraction and temperature of the main solid component in the tubular reactor cavity at the next time step at the current time step, that is, to predict the volume fraction and temperature of the main solid component in the reactor cavity.

[0061] S14. Grids whose predicted volume fraction distribution of the solid main component is greater than a preset fraction threshold are identified as target grids; calculate the free coke adhesion force in the target grid region, as well as the gravity and shear stress on the solid main component in the target grid region.

[0062] To reduce computational load and improve computational response rate, grid cells that do not contain the main solid component can be removed before calculating the spatial location and content of the coke adhering to the walls of the tubular reactor cavity, thereby reducing unnecessary computation. Preferably, in this embodiment of the invention, the preset fraction threshold can be set to 0.5%. In this way, grid cells whose predicted volume fraction distribution of the main solid component is greater than the preset fraction threshold can be identified as target grid cells, while other grid cells do not need to participate in subsequent calculations.

[0063] In this embodiment of the invention, calculating the adhesion of free coke in the target grid region, as well as the gravity and shear stress on the main solid component, can specifically be as follows:

[0064] A traversal approach is used to determine whether the free coke formed in each grid can overcome its own adhesive force or adhere to gravity and shear stress to continuously adhere to the reactor wall. Specifically, for each grid, the predicted temperature value for the next time step is first obtained. Then, based on the physicochemical properties of the free coke formed by the material, and according to the functional relationship between the adhesive force and temperature of the free coke, the adhesive force vector of the free coke in the next time step is obtained. Similarly, the gravity and shear stress vectors of the free coke in the next time step can also be obtained.

[0065] S15. Based on the adhesion, gravity, and shear stress of the free coke, determine whether the angle between the resultant force direction of the radial component of the target grid in the reactor and the normal direction of the wall tangent and the radial direction of the reactor is greater than 90°. If so, the target grid is determined as a coking grid.

[0066] To determine whether the main solid component of the target grid region can adhere to the inner wall of the reactor, a mechanical analysis is used to perform a force analysis on the radial cross-section of the tubular reactor. Specifically, the angle between the radial component of the resultant force of the adhesive force, gravity, and shear stress and the normal direction of the wall tangent (with the geometric center of the tubular reactor as the vector direction) is obtained. If it is greater than 90°, the target grid is identified as a coking grid (this coking grid is stored in the data set Coked) and marked as a coking space.

[0067] S16. Calculate the coke increment of each coking grid after one time step, and calculate the predicted coke adhesion amount after one time step based on the current coke inventory of the coking grid.

[0068] Traverse the grids in the Coked dataset. For each grid, based on the previous steps and combined with the lumped kinetics and reaction mechanism of the current process, calculate the coke increment of the current grid region in the next time step, and obtain the current coke stock in the Coked dataset in the current time step. Then, the sum of the two is recorded as the predicted coke adhesion amount Stock in the next time step.

[0069] S17. Calculate the gas-solid phase drag, liquid-solid phase drag, and convection diffusion for each of the coking grids after one time step, and record the sum of the three as the flow purging amount after one time step.

[0070] Next, calculate the gas-solid phase drag and liquid-solid phase drag of the current grid at the next time step, and calculate the convection-diffusion rate of the current grid at the next time step. Then, the sum of the three is recorded as the flow purging rate Sweep at the next time step.

[0071] When calculating the gas-solid interphase drag force, an energy-minimum multiscale model can be used. The model equations include:

[0072]

[0073] Among them, F gs The gas-solid phase drag force is represented by Re, the Reynolds coefficient is represented by ε, and the average porosity is represented by d. p Where ρ is the particle diameter, ρ is the average density, and u is the average density. g u is the apparent rate of gas. p denoted as the apparent rate of the particles.

[0074] When calculating the drag force between liquid and solid phases, the Schiller-Naumann uniform drag force model can be used. The model equations include:

[0075]

[0076]

[0077] Among them, F ls For the interphase drag force between liquid and solid phases, C D,ls denoted as the drag coefficient between the liquid and solid phases, and u as the apparent velocity of the fluid.

[0078] After obtaining the gas-solid phase drag and liquid-solid phase drag using the above method, calculate the convective diffusion amount of the current grid region at the next time step. Then, the sum of the three is recorded as the flow purging amount Sweep at the next time step.

[0079] S18. Calculate the predicted coke inventory of the coking grid after one time step by the difference between the predicted coke adhesion amount and the flow purging amount.

[0080] To estimate the final coke inventory at the next time step, this embodiment of the invention compares the predicted coke adhesion quantity (Stock) with the flow purging quantity (Sweep) from the previous steps. If the predicted coke adhesion quantity (Stock) is less than the flow purging quantity (Sweep), it indicates that the coke adhering to the wall of the grid at the next time step is insufficient. If the predicted coke adhesion quantity (Stock) is greater than the flow purging quantity (Sweep), the flow purging quantity (Sweep) is subtracted from the predicted coke adhesion quantity (Stock), and the data in the Coked dataset is updated. This updated data represents the final predicted coke inventory of the grid at the next time step.

[0081] S19. When the predicted coke inventory of the coking grid is greater than the preset coking rate threshold, increase the flow purging amount or jet temperature of the jet hole corresponding to the coking grid according to the preset rule, and return to step S13 as the updated flow purging amount or jet temperature; otherwise, generate the control command of the jet hole to which the coking grid belongs with the current flow purging amount or jet temperature as the target flow purging amount or target jet temperature.

[0082] In this embodiment of the invention, it is necessary to determine whether the mesh inside the tubular reactor cavity exceeds a preset coking rate critical value (preset coking rate critical value) at the next time step. The preset coking rate critical value in this embodiment of the invention is preferably no greater than 2%. Alternatively, it can be obtained by those skilled in the art based on experience or a limited number of experiments, and is not specifically limited here.

[0083] In practical applications, when determining whether the grid inside the tubular reactor cavity exceeds the preset coking rate threshold and adjusting the volume flux or jet temperature of the corresponding jet nozzle, the process can be carried out in parallel or one by one. That is, it can either calculate the adjustment amount of the volume flux or jet temperature of all jet nozzles that need to be adjusted after calculating the adjustment amount of the volume flux or jet temperature of the corresponding jet nozzle for each coking grid, and then return to step S13; or it can return to step S13 after calculating the adjustment amount of the volume flux or jet temperature of the corresponding jet nozzle for each coking grid, until all coking grids have been traversed.

[0084] Preferably, this step may specifically include the following sub-steps:

[0085] S21. Based on the three-dimensional simulation model, obtain the volumetric flux and temperature of each jet hole at the first time step, and divide the cavity of the tubular reactor into multiple decoking zones according to the spatial correlation weight, with each decoking zone corresponding to multiple jet holes; each jet hole is equipped with a wind cap.

[0086] In practical applications, the spatial correlation weight is used to characterize the tightness of the correlation between one or more grid regions and a corresponding jet nozzle. That is, the greater the numerical change in volumetric flux or temperature of a jet nozzle, the greater the numerical change in the wall coke residue of that region (including one or more grids). This can be regarded as the high spatial correlation weight of the jet nozzle to that region, and vice versa.

[0087] In practical applications, the decoking space within a tubular reactor cavity can be divided based on the spatial correlation weights. For each grid within the tubular reactor cavity, its spatial correlation weight with each jet nozzle can be obtained using this method. Therefore, the division of several decoking zones can be based on the spatial correlation weights between each grid and each jet nozzle, without necessarily requiring spatial continuity.

[0088] In practical applications, each grid can be represented as a function of f(x,y,z,size,type), where x,y,z represent the three-dimensional coordinates of the grid, size represents the grid size, and type represents the grid type. When the standard for determining the spatial correlation weight is set to the wall coke allowance, the relationship between the grid and each nozzle can be written as:

[0089]

[0090] in, This represents the initial amount of coke adhering to the wall in the i-th grid. This indicates the amount of coke adhering to the wall after the decoking gas is injected. Let be the decoking efficiency of the j-th jet nozzle. Let be the volumetric flux of the j-th nozzle, and T be the nozzle temperature. Therefore, the effect of the volumetric flux of each nozzle on the coke content adhering to the grid walls can be represented by the coefficient of variation Cv instead of the weighting value, i.e.:

[0091]

[0092] Where, f′ mean (T) is the average decoking amount of all jet nozzles on this grid, f σ (Q v ,T) represents the standard deviation of the amount of coke removed by the jet nozzle on the grid within a certain time step interval. Therefore, the larger Cv is, the higher the corresponding weight value.

[0093] In practical applications, since each jet nozzle and each decoking zone has varying degrees of spatial correlation, each decoking zone will correspond to multiple jet nozzles, and each jet nozzle will also correspond to several decoking zones. Each decoking zone can be controlled by one jet nozzle only when the maximum spatial correlation weight is used as the standard for controlling each decoking zone.

[0094] S22. Obtain the coking spatial location and coking amount based on the data in the Coked dataset, and determine the correspondence between the coking spatial location and the decoking interval;

[0095] At this point, the data set Coked contains the data set of the target grid where the total amount of coke adhering is greater than the flow purging amount;

[0096] S23. Set a Boolean array Bool for adjusting the volumetric flux or jet temperature of each jet orifice, and set an initial value;

[0097] In practical applications, the Boolean array Bool is only used to store values ​​that are True or False. During the execution of a computer program, the value False can be considered equivalent to the value of an int constant of 0, and the value True can be considered equivalent to the value of an int constant of 1.

[0098] In practical applications, the initial value of the Boolean array Bool depends on the specific reaction and operating conditions involved in the tubular reactor. If the volumetric flux of the decoking gas has a significant impact on the system temperature (for example, under microwave heating conditions, an excessive gas volumetric flux can easily cause electromagnetic field disturbances, thereby interfering with the microwave absorption properties of the material and thus affecting the temperature field), then the initial value of the Boolean array Bool is set to False. If the temperature of the decoking gas (i.e., the jet temperature) has a significant impact on the system temperature, then the initial value of the Boolean array Bool is set to True. If the two effects are similar, then the default initial value of the Boolean array Bool is True.

[0099] S24. Traverse the grids in the Coked dataset and determine whether the predicted coke inventory of each grid in the next time step is an over-standard grid exceeding the preset coking rate threshold. If the determination result is yes, determine the adjustment method of the jet nozzle corresponding to the coking removal interval of the over-standard grid according to the current state of the Boolean array Bool, and update the volume flux or jet temperature according to the adjustment method. After the traversal is completed, change the state of the Boolean array Bool and return the updated volume flux or jet temperature of each over-standard grid to step S13. If the determination result of all grids in the Coked dataset is no, use the current volume flux or jet temperature of the jet nozzle as the volume flux or jet temperature of each jet nozzle in the next time step, and generate the control command of the jet nozzle accordingly.

[0100] In this embodiment of the invention, the two states (True and False) of the Boolean array Bool are used to correspond to two adjustment methods: adjusting volumetric flux and adjusting jet temperature, respectively. Taking True for adjusting volumetric flux and False for adjusting jet temperature as an example, when the state of the Boolean array Bool is True, for out-of-range grids, the volumetric flux of the jet nozzle corresponding to the decoking zone where the out-of-range grid is located should be increased by a preset ratio in this traversal cycle. Since the state of the Boolean array Bool needs to be changed after each traversal cycle, the state of the Boolean array Bool should be False in the next traversal cycle. Therefore, for out-of-range grids, the jet temperature of the jet nozzle corresponding to the decoking zone where the out-of-range grid is located should be increased by a preset ratio in the next traversal cycle. Thus, this embodiment of the invention obtains an optimized ratio of volumetric flux and jet temperature of the jet nozzle by alternately adjusting volumetric flux and jet temperature.

[0101] It should be noted that the volumetric flux and flow purging rate of the jet nozzle in the embodiments of the present invention are interchangeable.

[0102] In practical applications, the volumetric flux and jet temperature of the jet nozzle can be adjusted either by performing parallel calculations on all coking grids and then adjusting them, or by performing calculations on each coking grid individually and then adjusting them.

[0103] In practical applications, the amount of coking on the wall of each coking grid in the tubular reactor can be used to determine whether it exceeds the preset coking rate threshold. If it does, the grids are sorted from largest to smallest based on the amount of coking. The adjustment is then started from the coking grid with the largest amount of coking, generating the volumetric flux or jet temperature adjustment of the jet corresponding to that coking grid, and returning to step S13.

[0104] It should be noted that the values ​​of the preset heating ratio and preset pressurization ratio in the embodiments of the present invention are adjustment ratios and can be determined by those skilled in the art based on actual working conditions or a limited number of experiments, and are not specifically limited here.

[0105] In summary, the embodiments of the present invention generate a corresponding three-dimensional simulation model based on the biomass pyrolysis device. Using the three-dimensional simulation model in these embodiments, the predicted volume fraction distribution of the main solid components and the predicted temperature distribution of the tubular reactor after one time step can be calculated. Then, the current flow purging rate of the coking grid and the predicted amount of coke adhesion after one time step can be further calculated. This allows it to determine whether the flow purging rate and jet temperature of the coking grid need adjustment in the next long time step. Furthermore, by quantitatively adjusting the flow purging rate and / or jet temperature of specific jet nozzles, the flow purging rate and / or jet temperature can be increased in targeted areas with excessive coking, thereby preventing excessive coking on the inner wall of the tubular reactor.

[0106] As can be seen from the above, the present invention uses a pre-judgment method to adjust the volumetric flux and temperature of the decoking gas nozzle in advance according to different operating conditions, thereby effectively improving the response speed of decoking control on the inner wall of the tubular reactor and thus improving the control effect of tar removal.

[0107] Example 2

[0108] Corresponding to the method embodiment, another aspect of the present invention also provides a decoking device for the inner wall of a tubular reactor. Figure 2 This diagram illustrates the structure of a decoking device for the inner wall of a tubular reactor provided in an embodiment of the present invention. The decoking device for the inner wall of the tubular reactor is... Figure 1 The device corresponding to the decoking method on the inner wall of the tubular reactor described in the corresponding embodiment is implemented through a virtual device. Figure 1 In the corresponding embodiment of the tubular reactor inner wall decoking method, the various virtual modules constituting the tubular reactor inner wall decoking device can be executed by electronic devices, such as network devices, terminal devices, or servers. Specifically, the tubular reactor inner wall decoking device in this embodiment of the invention includes:

[0109] Model building unit 01 is used to generate a corresponding three-dimensional simulation model based on the biomass pyrolysis device and to mesh it; the decoking mechanism of the biomass pyrolysis device includes a decoking gas generator and an air inlet duct arranged parallel to the inside of the tubular reactor and close to the upper part of the inner wall; the air inlet duct sprays decoking gas into the inner wall of the tubular reactor through a jet hole provided in the tubular reactor.

[0110] The parameter determination unit 02 is used to determine the input parameters of the three-dimensional simulation model, including: material feed rate, material temperature, inert gas inlet rate, volumetric flux of decoking gas, temperature of decoking gas, multiphase flow volume fraction, wall heat flux, wall roughness height, solid phase wall shear force, outlet pressure, and multiphase flow interphase drag force.

[0111] The simulation calculation unit 03 is used to obtain the steady-state simulation results of the three-dimensional simulation model based on the input parameters with a preset time step as the calculation period; the simulation results include the predicted volume fraction distribution of the solid phase main component of the tubular reactor after one time step, and the predicted temperature distribution.

[0112] The target grid determination unit 04 is used to determine the grids whose predicted volume fraction distribution of the solid phase main component is greater than a preset fraction threshold as target grids; and to calculate the free coke adhesion force in the target grid region, as well as the gravity and shear stress on the solid phase main component in the target grid region.

[0113] The coking grid judgment unit 05 is used to determine whether the angle between the resultant force direction of the target grid in the radial direction of the reactor and the normal direction of the wall tangent and the radial direction of the reactor is greater than 90° based on the adhesion force, gravity and shear stress of the free coke. If so, the target grid is determined as a coking grid.

[0114] The coke adhesion prediction unit 06 is used to calculate the coke increment of each coking grid after one time step, and to calculate the coke adhesion prediction amount after one time step based on the current coke inventory of the coking grid.

[0115] The purging quantity calculation unit 07 is used to calculate the gas-solid phase drag, liquid-solid phase drag, and convection diffusion of each coking grid after one time step, and to record the sum of the three as the flow purging quantity after one time step.

[0116] Coke inventory prediction unit 08 is used to calculate the predicted coke inventory of the coking grid after one time step by the difference between the predicted coke adhesion amount and the flow purging amount.

[0117] The control command generation unit 09 is used to increase the flow purging rate and / or jet temperature of the jet orifice corresponding to the coking grid according to a preset rule when the predicted coke inventory of the coking grid is greater than the preset coking rate threshold, and return the updated flow purging rate and / or jet temperature to the simulation calculation unit; otherwise, it generates a control command for the jet orifice to which the coking grid belongs, with the current flow purging rate and / or jet temperature as the target flow purging rate and / or target jet temperature.

[0118] It should be noted that the specific implementation method and technical effects of the decoking device on the inner wall of the tubular reactor in the embodiments of the present invention can be referred to Figure 1 The corresponding decoking methods for the inner wall of the tubular reactor will not be elaborated here.

[0119] Example 3

[0120] Corresponding to the method embodiments, this invention also provides a decoking device for the inner wall of a tubular reactor, such as a terminal or server. The server can be a standalone physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, CDN, and big data and artificial intelligence platforms. The terminal can be a smartphone, tablet, laptop, desktop computer, etc., but is not limited to these.

[0121] An example diagram of the hardware structure block diagram of the tubular reactor inner wall decoking device provided in this application embodiment is shown below. Figure 3 As shown, it may include:

[0122] Processor 1, communication interface 2, memory 3, and communication bus 4;

[0123] The processor 1, communication interface 2, and memory 3 communicate with each other via communication bus 4.

[0124] Optionally, communication interface 2 can be an interface of a communication module, such as the interface of a GSM module;

[0125] Processor 1 may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of this application.

[0126] Memory 3 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0127] Specifically, processor 1 is used to execute the computer program stored in memory 3 to perform the following steps:

[0128] S11. Generate a corresponding three-dimensional simulation model based on the biomass pyrolysis device and mesh it; the decoking mechanism of the biomass pyrolysis device includes a decoking gas generator and an air inlet duct arranged parallel to the inside of the tubular reactor and close to the upper part of the inner wall; the air inlet duct sprays decoking gas into the inner wall of the tubular reactor through a jet hole provided in the tubular reactor.

[0129] S12. Determine the input parameters of the three-dimensional simulation model, including: material feed rate, material temperature, inert gas inlet rate, volumetric flux of decoking gas, temperature of decoking gas, multiphase flow volume fraction, wall heat flux, wall roughness height, solid phase wall shear force, outlet pressure, and multiphase flow interphase drag force.

[0130] S13. Using a preset time step as the calculation period, obtain the simulation results of the three-dimensional simulation model under steady state according to the input parameters; the simulation results include the predicted volume fraction distribution of the solid phase main component of the tubular reactor after one time step, and the predicted temperature distribution.

[0131] S14. Grids whose predicted volume fraction distribution of the solid main component is greater than a preset fraction threshold are identified as target grids; calculate the free coke adhesion force in the target grid region, as well as the gravity and shear stress on the solid main component in the target grid region.

[0132] S15. Determine whether the angle between the resultant force direction of the target grid in the radial direction of the reactor and the normal direction of the wall tangent and the radial direction of the reactor is greater than 90° based on the adhesion force, gravity and shear stress of the free coke. If so, the target grid is determined as a coking grid.

[0133] S16. Calculate the coke increment of each coking grid after one time step, and calculate the predicted coke adhesion amount after one time step based on the current coke inventory of the coking grid.

[0134] S17. Calculate the gas-solid phase drag, liquid-solid phase drag, and convection diffusion for each of the coking grids after one time step, and record the sum of the three as the flow purging amount after one time step.

[0135] S18. Calculate the predicted coke inventory of the coking grid after one time step by the difference between the predicted coke adhesion amount and the flow purging amount.

[0136] S19. When the predicted coke inventory of the coking grid is greater than the preset coking rate threshold, increase the flow purging rate and / or jet temperature of the jet hole corresponding to the coking grid according to the preset rules, and return to step S13 as the updated flow purging rate and / or jet temperature; otherwise, generate control commands for the jet hole to which the coking grid belongs, with the current flow purging rate and / or jet temperature as the target flow purging rate and / or target jet temperature.

[0137] The above-described product can perform the method provided in the embodiments of the present invention, and has the corresponding functional modules and beneficial effects for performing the method. Technical details not described in detail in this embodiment can be found in the method for decoking the inner wall of a tubular reactor provided in the embodiments of the present invention.

[0138] Example 4

[0139] In this embodiment of the invention, a storage medium is also provided, which can store a program suitable for execution by a processor, the program being used for:

[0140] S11. Generate a corresponding three-dimensional simulation model based on the biomass pyrolysis device and mesh it; the decoking mechanism of the biomass pyrolysis device includes a decoking gas generator and an air inlet duct arranged parallel to the inside of the tubular reactor and close to the upper part of the inner wall; the air inlet duct sprays decoking gas into the inner wall of the tubular reactor through a jet hole provided in the tubular reactor.

[0141] S12. Determine the input parameters of the three-dimensional simulation model, including: material feed rate, material temperature, inert gas inlet rate, volumetric flux of decoking gas, temperature of decoking gas, multiphase flow volume fraction, wall heat flux, wall roughness height, solid phase wall shear force, outlet pressure, and multiphase flow interphase drag force.

[0142] S13. Using a preset time step as the calculation period, obtain the simulation results of the three-dimensional simulation model under steady state according to the input parameters; the simulation results include the predicted volume fraction distribution of the solid phase main component of the tubular reactor after one time step, and the predicted temperature distribution.

[0143] S14. Grids whose predicted volume fraction distribution of the solid main component is greater than a preset fraction threshold are identified as target grids; calculate the free coke adhesion force in the target grid region, as well as the gravity and shear stress on the solid main component in the target grid region.

[0144] S15. Determine whether the angle between the resultant force direction of the target grid in the radial direction of the reactor and the normal direction of the wall tangent and the radial direction of the reactor is greater than 90° based on the adhesion force, gravity and shear stress of the free coke. If so, the target grid is determined as a coking grid.

[0145] S16. Calculate the coke increment of each coking grid after one time step, and calculate the predicted coke adhesion amount after one time step based on the current coke inventory of the coking grid.

[0146] S17. Calculate the gas-solid phase drag, liquid-solid phase drag, and convection diffusion for each of the coking grids after one time step, and record the sum of the three as the flow purging amount after one time step.

[0147] S18. Calculate the predicted coke inventory of the coking grid after one time step by the difference between the predicted coke adhesion amount and the flow purging amount.

[0148] S19. When the predicted coke inventory of the coking grid is greater than the preset coking rate threshold, increase the flow purging rate and / or jet temperature of the jet hole corresponding to the coking grid according to the preset rules, and return to step S13 as the updated flow purging rate and / or jet temperature; otherwise, generate control commands for the jet hole to which the coking grid belongs, with the current flow purging rate and / or jet temperature as the target flow purging rate and / or target jet temperature.

[0149] Optionally, the refined and extended functions of the program can be found in the description above.

[0150] The above-described product can execute the methods provided in the embodiments of the present invention, and has the corresponding functional modules and beneficial effects for executing the methods. Technical details not described in detail in this embodiment can be found in the methods provided in other embodiments of the present invention.

[0151] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0152] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. Furthermore, the couplings or direct couplings or communication connections shown or discussed may be indirect couplings or communication connections through interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0153] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0154] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0155] It should be understood that in the embodiments of this application, the claims, various embodiments, and features can be combined with each other to solve the aforementioned technical problems.

[0156] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0157] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for removing coke from the inner wall of a tubular reactor, characterized in that, Including the following steps: S11. Generate a corresponding three-dimensional simulation model based on the biomass pyrolysis device and mesh it; the decoking mechanism of the biomass pyrolysis device includes a decoking gas generator and an air inlet duct arranged parallel to the inside of the tubular reactor and close to the upper part of the inner wall; the air inlet duct sprays decoking gas into the inner wall of the tubular reactor through a jet hole provided in the tubular reactor. S12. Determine the input parameters of the three-dimensional simulation model, including: material feed rate, material temperature, inert gas inlet rate, volumetric flux of decoking gas, temperature of decoking gas, multiphase flow volume fraction, wall heat flux, wall roughness height, solid phase wall shear force, outlet pressure, and multiphase flow interphase drag force. S13. Using a preset time step as the calculation period, obtain the simulation results of the three-dimensional simulation model under steady state according to the input parameters; the simulation results include the predicted volume fraction distribution of the solid phase main component of the tubular reactor after one time step, and the predicted temperature distribution. S14. Grids whose predicted volume fraction distribution of the solid main component is greater than a preset fraction threshold are identified as target grids; calculate the free coke adhesion force in the target grid region, as well as the gravity and shear stress on the solid main component in the target grid region. S15. Determine whether the angle between the resultant force direction of the target grid in the radial direction of the reactor and the normal direction of the wall tangent and the radial direction of the reactor is greater than 90° based on the adhesion force, gravity and shear stress of the free coke. If so, the target grid is determined as a coking grid. S16. Calculate the coke increment of each coking grid after one time step, and calculate the predicted coke adhesion amount after one time step based on the current coke inventory of the coking grid. S17. Calculate the gas-solid phase drag, liquid-solid phase drag, and convection diffusion for each of the coking grids after one time step, and record the sum of the three as the flow purging amount after one time step. S18. Calculate the predicted coke inventory of the coking grid after one time step by the difference between the predicted coke adhesion amount and the flow purging amount. S19. When the predicted coke inventory of the coking grid is greater than the preset coking rate threshold, increase the flow purging amount or jet temperature of the jet hole corresponding to the coking grid according to the preset rule, and return to step S13 as the updated flow purging amount or jet temperature; otherwise, generate the control command of the jet hole to which the coking grid belongs with the current flow purging amount or jet temperature as the target flow purging amount or target jet temperature.

2. The method for removing coke from the inner wall of a tubular reactor according to claim 1, characterized in that, The step of increasing the flow purging rate of the jet orifice corresponding to the coking grid according to a preset rule includes: The flow rate of the jet orifice corresponding to the coking grid is increased according to the preset pressurization ratio.

3. The method for removing coke from the inner wall of a tubular reactor according to claim 1, characterized in that, When the predicted coke inventory of the coking grid is greater than a preset coking rate threshold, increasing the flow purging rate and / or jet temperature of the jet orifice corresponding to the coking grid according to a preset rule includes: S21. Based on the three-dimensional simulation model, obtain the volumetric flux and temperature of each jet hole at the first time step, and divide the cavity of the tubular reactor into multiple decoking zones according to the spatial correlation weight, with each decoking zone corresponding to multiple jet holes; each jet hole is equipped with a wind cap. S22. Obtain the coking spatial location and coking amount based on the data in the Coked dataset, and determine the correspondence between the coking spatial location and the decoking interval; the Coked dataset is the dataset of the target grid where the total amount of coke adhesion is greater than the flow purging amount. S23. Set a Boolean array Bool for adjusting the volumetric flux or jet temperature of each jet orifice, and set an initial value; S24. Traverse the grids in the Coked dataset and determine whether the predicted coke inventory of each grid in the next time step is an over-standard grid exceeding the preset coking rate threshold. If the determination result is yes, determine the adjustment method of the jet nozzle corresponding to the coking removal interval where the over-standard grid is located based on the current state of the Boolean array Bool, and update the volume flux or jet temperature according to the adjustment method. After the traversal is completed, change the state of the Boolean array Bool, and return the updated volume flux or jet temperature of each over-standard grid to step S13. If the determination result of all grids in the Coked dataset is no, use the current volume flux and jet temperature of the jet nozzle as the volume flux and jet temperature of each jet nozzle in the next time step, and generate the control command for the jet nozzle accordingly.

4. The method for removing coke from the inner wall of a tubular reactor according to claim 1, characterized in that, The heating method of the pyrolysis device includes: One or more of the following: electric heating, microwave heating, plasma heating, laser heating, and electron beam heating.

5. The method for removing coke from the inner wall of a tubular reactor according to claim 1, characterized in that, The step of generating a corresponding three-dimensional simulation model based on the biomass pyrolysis device and meshing it includes: Let the volume of the tubular reactor in the three-dimensional simulation model be V; and the number of jet nozzles be n. Let the feed volume flux of the i-th nozzle be Qv. i The angle is Deg i The temperature is T0 i ; The meshed 3D simulation model has d meshes and is stored in a set Data, where the temperature of the i-th mesh is T. i Coking amount is Coke i .

6. The method for decoking the inner wall of a tubular reactor according to claim 1, characterized in that, The formula for calculating the gas-solid phase drag force includes: An energy-minimum multiscale model is adopted, and the equations of the energy-minimum multiscale model include: Among them, F gs The gas-solid phase drag force is represented by Re, the Reynolds coefficient is represented by ε, and the average porosity is represented by d. p Where ρ is the particle diameter, ρ is the average density, and u is the average density. g u is the apparent rate of gas. p denoted as the apparent rate of the particles.

7. The method for decoking the inner wall of a tubular reactor according to claim 1, characterized in that, The formula for calculating the interphase drag force includes: The Schiller-Naumann uniform drag model is adopted, and the equations of the Schiller-Naumann uniform drag model include: Among them, F ls For the interphase drag force between liquid and solid phases, C D,ls denoted as the drag coefficient between the liquid and solid phases, and u as the apparent velocity of the fluid.

8. A decoking device for the inner wall of a tubular reactor, characterized in that, include: The model building unit is used to generate a corresponding three-dimensional simulation model based on the biomass pyrolysis device and to mesh it; the decoking mechanism of the biomass pyrolysis device includes a decoking gas generator and an air inlet duct arranged parallel to the inside of the tubular reactor and close to the upper part of the inner wall; the air inlet duct sprays decoking gas into the inner wall of the tubular reactor through a jet hole provided in the tubular reactor. The parameter determination unit is used to determine the input parameters of the three-dimensional simulation model, including: material feed rate, material temperature, inert gas inlet rate, decoking gas volume flux, decoking gas temperature, multiphase flow volume fraction, wall heat flux, wall roughness height, solid phase wall shear force, outlet pressure, and multiphase flow interphase drag force. The simulation calculation unit is used to obtain the steady-state simulation results of the three-dimensional simulation model based on the input parameters, with a preset time step as the calculation period; the simulation results include the predicted volume fraction distribution of the solid phase main component of the tubular reactor after one time step, and the predicted temperature distribution. The target grid determination unit is used to determine the grids whose predicted volume fraction distribution of the solid phase main component is greater than a preset fraction threshold as target grids; the free coke adhesion force in the target grid region, and the gravity and shear stress on the solid phase main component in the target grid region are calculated respectively; The coking grid determination unit is used to determine whether the angle between the resultant force direction of the target grid in the radial direction of the reactor and the normal direction of the wall tangent and the radial direction of the reactor is greater than 90° based on the adhesion force, gravity and shear stress of the free coke. If so, the target grid is determined as a coking grid. The coke adhesion prediction unit is used to calculate the coke increment of each coking grid after one time step, and to calculate the predicted coke adhesion amount after one time step based on the current coke inventory of the coking grid. The purging quantity calculation unit is used to calculate the gas-solid phase drag, liquid-solid phase drag, and convective diffusion of each coking grid after one time step, and to record the sum of the three as the flow purging quantity after one time step; The coke inventory prediction unit is used to calculate the predicted coke inventory of the coking grid after one time step by the difference between the predicted coke adhesion amount and the flow purging amount. The control command generation unit is used to increase the flow purging rate or jet temperature of the jet hole corresponding to the coking grid according to a preset rule when the predicted coke inventory of the coking grid is greater than the preset coking rate threshold, and return the updated flow purging rate or jet temperature to the simulation calculation unit; otherwise, it generates the control command of the jet hole to which the coking grid belongs, with the current flow purging rate or jet temperature as the target flow purging rate or target jet temperature.

9. A decoking device for the inner wall of a tubular reactor, characterized in that, include: Memory, used to store computer programs; A processor is configured to invoke and execute the computer program to implement the steps of the decoking method for the inner wall of a tubular reactor as described in any one of claims 1-7.

10. A storage medium, characterized in that, Includes software programs adapted for execution by a processor of the steps of the decoking method for the inner wall of the tubular reactor as described in any one of claims 1-7.

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