Vertical moving bed type biomass pyrolysis reactor and control method thereof

Abstract

The application discloses a vertical moving bed biomass pyrolysis reactor and a use method thereof, and the biomass pyrolysis reactor comprises a microwave heating device, a vertical moving bed and a control device; the microwave heating device comprises a feeding screw shaft, a microwave heating cavity and a microwave generator provided with a plurality of controllable microwave sources; the feeding screw shaft conveys materials to pass through a tubular reactor in the microwave heating cavity for heating and then falls into the vertical moving bed; the vertical moving bed comprises a microwave absorption cavity located at an upper portion and a reaction cavity located at a lower portion; a plurality of tower plates coated with a wave-absorbing coating are arranged in the microwave absorption cavity; the tower plates are used for absorbing residual electromagnetic waves; the control device performs a control action of the controllable microwave source and / or the feeding screw shaft according to a power adjustment instruction and / or a rotating speed adjustment instruction; and the application will not cause pipeline blockage and gas backflow due to high-temperature sintering, so that normal operation of process production is effectively ensured.

Description

Technical Field

[0001] This invention relates to the field of chemical processes, and in particular to a vertical moving bed biomass pyrolysis reactor and its control method. Background Technology

[0002] Hydrogen production is currently a hot topic in the energy industry. Since the large amount of tar produced by biomass pyrolysis using traditional heating methods is difficult to handle, the use of microwave penetration and selective heating has become a feasible solution for the production of "green hydrogen".

[0003] Since the secondary treatment after microwave pyrolysis requires the removal of tar using combustion-supporting gases in a high-temperature environment, in order to avoid phenomena such as flash explosions and "ignition" that endanger safe production, it is necessary to use cutoff waveguides to shield electromagnetic waves in subsequent processes to weaken the electromagnetic field strength to a safe range.

[0004] In existing technologies, chemical engineering typically employs cutoff waveguides to prevent electromagnetic waves from entering a specific work area, thereby preventing electromagnetic radiation interference and ensuring production process and personal safety.

[0005] The inventors discovered through research that the existing technology using cutoff waveguides has at least the following drawbacks:

[0006] In biomass pyrolysis processes, reaction raw materials with high carbon content are often included. The solid components in these raw materials may exhibit an amorphous viscous state due to high temperature, the adhesion of aromatic substances (mainly tar), pore collapse, and other reasons. Since the pore size of the cutoff waveguide is small, the cutoff waveguide located at the reactor outlet is likely to cause pipe blockage and gas backflow due to high-temperature sintering, thereby affecting the normal operation of the process.

[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 improve the stability of biomass pyrolysis processes using microwaves as a heating source.

[0009] This invention provides a vertical moving bed biomass pyrolysis reactor, comprising a microwave heating device, a vertical moving bed, and a control device;

[0010] The microwave heating device includes a feed screw shaft, a microwave heating cavity, and a microwave generator equipped with multiple controllable microwave sources; the feed screw shaft conveys material through a tubular reactor in the microwave heating cavity for heating before it falls into the vertical moving bed;

[0011] The vertical moving bed includes a microwave absorption cavity at the top and a reaction cavity at the bottom; the microwave absorption cavity is provided with multiple trays coated with microwave absorbing coatings; the trays are used to absorb residual electromagnetic waves;

[0012] The control device executes the controllable microwave source and / or the feed screw shaft control actions according to the power adjustment command and / or speed adjustment command.

[0013] Preferably, in this embodiment of the invention, a processing device is further included, comprising:

[0014] The model calculation unit is used to calculate the simulation results of the three-dimensional electromagnetic field model according to the preset input parameters with a preset time step as the calculation period. The simulation results include the predicted values ​​of the temperature field distribution and the predicted values ​​of the electromagnetic field strength of each cavity after one time step. The three-dimensional electromagnetic field model is generated and meshed based on the biomass pyrolysis reactor. The input parameters include the current microwave frequency and current microwave power of each controllable microwave source, the dielectric constant and feed rate of the material, the current dielectric properties of the absorbing coating, and the mathematical model of the dielectric properties of the absorbing coating with frequency and temperature.

[0015] The dielectric property calculation unit is used to calculate the predicted dielectric properties of the microwave absorbing coating in the microwave absorbing cavity based on the predicted temperature field distribution and the input parameters.

[0016] An electromagnetic field strength calculation unit is used to calculate the predicted electromagnetic field strength correction value in the reaction cavity based on the predicted electromagnetic field strength estimate of each cavity and the predicted dielectric properties.

[0017] The power adjustment command unit is used to determine whether the reaction cavity contains an out-of-standard grid exceeding a preset threshold after one time step based on the predicted electromagnetic field strength correction value. If so, the current microwave power of the controllable microwave source is reduced according to a preset rule and returned to the model calculation unit; if not, a microwave power adjustment command for the controllable microwave source corresponding to the out-of-standard grid is generated with the current microwave power as the target microwave power.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] In this invention, a feeding screw shaft is used to transport materials. The rotation of the screw blades not only propels the materials but also continuously agitates them, ensuring uniform heating of the materials entering the microwave heating cavity and reducing hot spot effects. Furthermore, the rotating screw blades can scrape away carbonized residues from the tubular reactor wall after the material reaction at high temperatures, preventing blockage. Next, the vertical moving bed in this invention also includes a microwave absorption cavity at the top. Through a tower plate coated with a microwave-absorbing layer, the heated materials are absorbed to eliminate residual electromagnetic waves in the materials, as well as residual electromagnetic waves diffracted / reflected from the microwave heating cavity that are not fully absorbed and thus enter the microwave absorption cavity.

[0020] Because this invention uses a feed screw shaft and a tower plate coated with a microwave-absorbing coating, it can uniformly heat and absorb microwaves on the material without affecting the continuous flow of the material in each cavity. Because this invention does not cause pipe blockage or gas backflow due to high-temperature sintering, it effectively ensures the normal operation of the production process.

[0021] Furthermore, in this invention, a three-dimensional electromagnetic field model is generated based on the modeling of the biomass pyrolysis reactor. By predicting the temperature field distribution and electromagnetic field strength of each chamber in the reactor, the predicted dielectric properties of the absorbing coating are obtained. Thus, the actual effect of the absorbing coating in shielding microwaves within the reactor can be obtained based on the predicted values. Next, the purpose of setting up a microwave transition sub-cavity in this invention is to calculate the electromagnetic field strength within the cavity and then intuitively predict whether the microwave cutoff rate at the next time step is met using numerical simulation. Then, the dielectric properties of the current absorbing coating are recorded. Based on this, when it is predicted that the microwave cutoff rate at the next time step will not meet the standard, the microwave power of the controllable microwave source is pre-adjusted to assist in adjusting the process conditions, thereby ensuring that the subsequent reaction chamber with combustion-supporting gas can completely shield or weaken microwaves to a safe electromagnetic field strength range.

[0022] 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

[0023] 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.

[0024] Figure 1 This is a flowchart illustrating the steps of the vertical moving bed biomass pyrolysis reactor described in this invention.

[0025] Figure 2 This is a schematic diagram of the structure of the microwave absorption performance control device of the microwave absorbing coating described in this invention;

[0026] Figure 3 This is a schematic diagram of the control equipment structure of the vertical moving bed biomass pyrolysis reactor described in this invention. Detailed Implementation

[0027] 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.

[0028] 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.

[0029] 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.

[0030] Example 1

[0031] To improve the stability of biomass pyrolysis processes using microwaves as a heating source, such as... Figure 1 As shown, in this embodiment of the invention, a vertical moving bed biomass pyrolysis reactor is provided, including a microwave heating device, a vertical moving bed, and a control device 03;

[0032] The microwave heating device includes a feed screw shaft 11, a microwave heating cavity 12, and a microwave generator (not shown in the figure) equipped with multiple controllable microwave sources 13. The feed screw shaft 11 conveys material through the tubular reactor 14 in the microwave heating cavity 12 for heating and then it falls into a vertical moving bed. The vertical moving bed includes a microwave absorption cavity 21 located at the top and a reaction cavity 22 located at the bottom. The microwave absorption cavity 21 is equipped with multiple trays 23 coated with microwave absorbing coatings. The trays 23 absorb residual electromagnetic waves in the material and residual electromagnetic waves diffracted / reflected from the microwave heating cavity 12 into the microwave absorption cavity 21 by temporarily contacting the heated material. The control device 03 executes the control actions of the controllable microwave sources 13 and / or the feed screw shaft 11 according to the power adjustment command and / or speed adjustment command.

[0033] In practical applications, a material feeding bin 15 is also required to convey materials to the feeding screw shaft 11. The material feeding bin 15 can be made of stainless steel, has a certain volume, and is connected to the space inside the microwave heating cavity 12. The two are sealed to prevent air leakage.

[0034] The material feed hopper 15 is the feed inlet of the entire continuous feeding vertical moving bed biomass pyrolysis reactor. In order to facilitate the material entering the microwave heating chamber 12, the material feed hopper 15 can adopt an inverted cone design. The material layer height formed by the space inside the hopper is supplemented by the slight negative pressure formed by the feed screw shaft and the Roots blower to transport the material, ensuring the continuity and stability of the feeding rate.

[0035] The microwave generator in this embodiment of the invention mainly includes a magnetron capable of generating fixed-frequency microwave signals using frequency synthesis technology, and a power supply device for supplying power to the magnetron. The power supply device converts common AC power into DC power, while the magnetron converts the DC power from the power supply device into microwave energy and transmits it. A microwave waveguide transmits the microwaves generated by the microwave generator from the outside of the microwave heating cavity to the medium inside the cavity. To prevent microwave leakage and radiation, the microwave waveguide medium used in this embodiment of the invention can be a hollow, enclosed waveguide made of metal.

[0036] In this embodiment of the invention, the microwave heating cavity 12 has an outer wall made of metal material and is sealed to the microwave waveguide, while the cavity space is connected to the internal space of the microwave waveguide.

[0037] A tubular reactor 14 can be horizontally placed inside the microwave heating cavity 12 for heating and transporting materials. In practical applications, the wall of the tubular reactor can be sealed to the material feed hopper 15, the microwave absorption cavity 21, and the microwave heating cavity 12 to prevent leakage of materials and their reaction products. Meanwhile, the internal space of the tubular reactor 14 is connected to the space inside the material feed hopper 15 and the microwave absorption cavity 21, but not to the space inside the microwave heating cavity 12.

[0038] In this embodiment of the invention, the feed screw shaft 11 is a fixed shaft with helical blades, horizontally positioned within the tubular reactor 14 in the microwave heating cavity 12. The helical blades are at a certain angle to the wall of the tubular reactor, and the closer to the end of the screw shaft, the smaller the spacing (i.e., the pitch) of the helical blades. A drive motor is also connected to the front end of the feed screw shaft 11 to drive its rotation. When the material enters the feed hopper, the motor drives the feed screw shaft 11 to rotate clockwise around its axis. While mixing the material, the helical blades can also scrape away the carbonized residue on the tubular reactor wall after the material reacts at high temperature, preventing material blockage.

[0039] The vertical moving bed in this embodiment of the invention has an hourglass-shaped overall appearance. The upper part is the microwave absorption cavity 21, which is used to replace the cutoff waveguide to shield or weaken the electromagnetic field strength. The lower part is the reaction cavity 22 of the vertical moving bed, which is used to introduce the gaseous substances required for the process. The diameter change point connecting the upper and lower ends is called the throat area 24, which is provided with a combustion-supporting gas interface for introducing the combustion-supporting gas required for the process.

[0040] The outer wall of the vertical moving bed with microwave absorption cavity 21 is entirely made of metal. The inlet of the upper microwave absorption cavity 21 is connected to the tubular reactor 14 with a sealing device made of metal to prevent microwaves from leaking from the absorption cavity to the outside of the cavity. The lower part is connected to gas-solid two-phase outlets. The bottom is equipped with a slag discharge device, the length of which can extend into the space away from the microwave cavity to facilitate the removal of solid materials. The other gas phase outlet is on the outer wall of the lower part of the vertical moving bed. Its space is connected to the space inside the cyclone dust collector by welding a gas pipe to prevent leakage of gas phase products.

[0041] In this embodiment of the invention, the microwave absorption cavity 21 is internally equipped with multiple trays 23 coated with microwave-absorbing coatings. These trays 23 are arranged in upper and lower layers and tilted downwards. This allows material falling into the microwave absorption cavity 21 to first contact the top tray for microwave absorption, then slide down to the next tray for further absorption, and so on, repeatedly absorbing the material. Similarly, residual electromagnetic waves that are not completely absorbed in the microwave heating cavity 12, after diffraction / reflection, enter the microwave absorption cavity 21. During propagation, these waves are first absorbed by the microwave-absorbing coating on the top tray, weakening their intensity, then move to the next tray for further absorption, and so on, repeatedly weakening the electromagnetic wave intensity until it disappears completely or is reduced to a level suitable for safe production.

[0042] In practical applications, the width of the tray 23 is the same as the diameter of the vertical moving bed, while the length is slightly longer than the radius of the bed. That is, the edge of the tray 23 extends beyond the center point of the cross-section of the microwave absorption cavity 21. Preferably, the shape of the tray 23 is an arc.

[0043] Considering the reliability of continuous material falling and the purpose of weakening microwave field strength, the tilt angle of the tower plate 23 in this embodiment of the invention is 5-30°, the shape of the tower plate 23 is semi-circular arc, and its arc part is in contact with the microwave absorption cavity wall. The projected area after tilting is greater than 50% of the cross-sectional area of ​​the microwave absorption cavity 21.

[0044] In practical applications, the microwave absorbing coating in the embodiments of the present invention can be one or more of the following: Mn-Zn, Ni-Zn, Li-Ti series of stony ferrites, SiC ceramics, retinol Schiff base and its complexes, carbonyl iron powder, carbonyl nickel powder, fibers, nickel fibers, cobalt fibers and their alloy fibers, and more preferably SiC ceramics.

[0045] In practical applications, the thickness of the microwave absorbing coating in the embodiments of the invention can range from 100 to 800 g / L, and is more preferably 200 to 600 g / L.

[0046] In practical applications, the feed screw shaft 11 in this embodiment of the invention can be configured as a detachable connection. Then, depending on the specific process conditions, different materials can be selected for the feed screw shaft. Specifically, when the overall process uses raw materials with poor microwave absorption, the feed screw shaft 11 can be made of graphite composite material, which indirectly acts as a microwave absorber in the reaction process, thereby enhancing the overall microwave heating efficiency. When the overall process requires high temperature uniformity, the feed screw shaft 11 can be made of metal material, such as 304 steel, which can then disturb the electromagnetic field distribution through microwave reflection caused by the rotation of the blades, thereby weakening the hot spot effect in the microwave heating cavity and improving the thermal field uniformity of the overall process.

[0047] Since the tubular reactor 14 is connected to the microwave heating cavity 12 and the microwave absorption cavity 21, the disassembly part of the feed screw shaft 11 is located on the drive motor side. Furthermore, to ensure no microwave leakage within the cavity, a metal-contact dynamic seal is typically used. It should be noted that this detachable design also facilitates equipment maintenance when blockages occur during material transmission within the microwave heating cavity 12.

[0048] In practical applications, the vertical moving bed in this embodiment of the invention has a throat region 24 in the lower half of the microwave absorption cavity 21 for introducing the combustion-supporting gas required for the process. From a safety perspective, a microwave field strength detector is installed in the throat region 24 to detect whether the microwave field strength has been completely absorbed or weakened to a safe range through the microwave absorption cavity 21. A controller is also connected to the microwave field strength detector to transmit control signals. Specifically, when the microwave field strength detector detects that the microwave field strength transmitted from the upper part of the throat region exceeds a set value, it immediately blows the fuse of the microwave generator and terminates the transmission of the combustion-supporting gas. From a process optimization perspective, the lowermost region of the hourglass shape of the throat region 24, through its variable diameter design, can increase the residence time of the material or the post-reaction gas phase, facilitating sufficient contact with the combustion-supporting gas introduced into the throat region 24, thereby improving the purity of subsequent products.

[0049] In summary, in this embodiment of the invention, by using a feed screw shaft to transport materials, the rotation of the screw blades not only propels the materials but also continuously agitates them. This ensures that the materials entering the microwave heating cavity are heated evenly, reducing the generation of hot spot effects. Furthermore, the rotating screw blades can scrape away carbonized residues from the tubular reactor wall after the material reaction at high temperatures, preventing material blockage. Next, the vertical moving bed in this embodiment of the invention also includes a microwave absorption cavity at the top. Through a tower plate coated with a microwave-absorbing layer, the heated materials are absorbed to eliminate residual electromagnetic waves in the materials, as well as residual electromagnetic waves diffracted / reflected from the microwave heating cavity that are not fully absorbed and thus enter the microwave absorption cavity.

[0050] Because the embodiments of the present invention employ a feeding screw shaft and a tower plate coated with a microwave-absorbing coating, the material can be uniformly heated and microwave-absorbing without affecting the continuous flow of the material in each cavity. Since the embodiments of the present invention do not cause pipe blockage or gas backflow due to high-temperature sintering, the normal operation of the process production is effectively guaranteed.

[0051] Example 2

[0052] Based on Embodiment 1, this embodiment of the invention further provides a control method for a vertical moving bed biomass pyrolysis reactor to automatically generate power adjustment commands and speed adjustment commands, so as to avoid microwave leakage into the reaction chamber due to incomplete microwave blocking by the microwave absorbing coating. Specific steps include:

[0053] S11. Using a preset time step as the calculation period, the simulation results of the three-dimensional electromagnetic field model are calculated based on preset input parameters. The simulation results include the predicted temperature field distribution and electromagnetic field strength of each cavity after one time step. The three-dimensional electromagnetic field model is generated and meshed based on the biomass pyrolysis reactor. The input parameters include the current microwave frequency and current microwave power of each controllable microwave source, the dielectric constant and feed rate of the material, the current dielectric properties of the absorbing coating, and the mathematical model of the dielectric properties of the absorbing coating with frequency and temperature.

[0054] This invention utilizes three-dimensional electromagnetic field simulation technology to simulate the electromagnetic field strength and temperature distribution data within each cavity of a microwave reactor.

[0055] In practical applications, based on the modeling of a biomass pyrolysis reactor, the reactor wall, material inlet, material outlet, microwave heating cavity, microwave absorption cavity, and reaction cavity are set up. A three-dimensional electromagnetic field model is generated and meshed. Specifically, this can be done in the following ways:

[0056] Let the internal volume of the microwave heating cavity be V. rThe internal volume of the microwave absorption cavity is V. a The internal volume of the reaction chamber is V. t The number of each controllable microwave source is n;

[0057] Let the power of the i-th controllable microwave source be P. i The total power of the microwave pyrolysis reactor is

[0058] The meshed three-dimensional electromagnetic field model has d mesh elements and is stored in set D, where the electromagnetic intensity of the i-th mesh element belonging to set D is E. i The temperature is T i .

[0059] In practical applications, the mesh 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.

[0060] Before simulating the electromagnetic field strength and temperature field distribution inside the cavity, it is necessary to obtain various input parameters of the three-dimensional electromagnetic field model. Specifically, these parameters may include the current microwave frequency and current microwave power of each controllable microwave source, the dielectric constant and feed rate of the heated material, the current dielectric properties of the absorbing coating, and the mathematical model of the dielectric properties of the absorbing coating as a function of frequency and temperature.

[0061] In this embodiment of the invention, the simulation results of the three-dimensional electromagnetic field model calculated based on the input parameters are periodic, that is, a calculation is performed every time step. In practical applications, the value of the time step can be determined based on the actual computing power of the computer and the experience of those skilled in the art, and no specific limitation is made here.

[0062] In this embodiment of the invention, the purpose of calculating the simulation results of the three-dimensional electromagnetic field model based on the input parameters is to obtain the predicted values ​​of the temperature field distribution and electromagnetic field strength of the reactor cavity at the current time and the next time step. That is, based on the current dielectric properties of the absorbing coating, the temperature field distribution and electromagnetic field strength of each cavity of the reactor are estimated in units of grid, and the estimated values ​​of the temperature and electromagnetic field strength of each grid are obtained.

[0063] S12. Calculate the predicted dielectric properties of the absorbing coating in the microwave absorber cavity based on the predicted temperature field distribution and the input parameters.

[0064] The dielectric properties of the microwave absorbing coating are affected by temperature. Therefore, after obtaining the predicted temperature field distribution over a long period of time, the predicted dielectric properties of the microwave absorbing coating over a long period of time can be calculated using the grid of the three-dimensional electromagnetic field model as the unit, based on the mathematical model of dielectric properties with frequency and temperature.

[0065] S13. Calculate the predicted electromagnetic field strength correction value in the reaction cavity based on the predicted electromagnetic field strength estimate and the predicted dielectric properties of each sub-cavity.

[0066] The dielectric properties of the absorbing coating may change over a longer period of time, and the electromagnetic field strength prediction estimate obtained in step S11 is based on the dielectric properties at the current moment, so its value will have a certain error. In view of this, in this embodiment of the invention, after obtaining the electromagnetic field strength prediction estimate, the electromagnetic field strength prediction estimate is also corrected by the predicted dielectric properties over a longer period of time to obtain a more accurate predicted electromagnetic field strength correction value in the reaction cavity.

[0067] S14. Based on the predicted electromagnetic field strength correction value, determine whether the reaction cavity contains an out-of-standard grid exceeding a preset threshold after one time step. If yes, reduce the current microwave power of the controllable microwave source according to the preset rule and return to step S11; if no, generate a microwave power adjustment command for the controllable microwave source corresponding to the out-of-standard grid with the current microwave power as the target microwave power.

[0068] To promptly prevent microwave cutoff rates from exceeding limits, this embodiment of the invention employs a method that, once a grid is detected in the microwave transition subcavity, the power of the controllable microwave source corresponding to the grid exceeding the preset safety threshold will be reduced in the next step. Because this method requires relatively little computation, it effectively improves the control response speed. Specifically, it can be:

[0069] When the reaction cavity contains an out-of-standard grid whose predicted electromagnetic field strength exceeds a preset safety threshold, the current microwave power of the controllable microwave source corresponding to the out-of-standard grid is reduced according to a preset ratio. In practical applications, the specific value of the preset ratio can be selected within 2% to 5%, and more preferably within 2% to 3%.

[0070] It should be noted that the preset threshold in the embodiments of the present invention can be obtained by those skilled in the art based on actual conditions or a limited number of experiments, and is not specifically limited here.

[0071] In summary, because the present invention employs a feed screw shaft and a tower plate coated with a microwave-absorbing coating, it is possible to uniformly heat and absorb microwaves on the material without affecting the continuous flow of the material in each cavity. Since the present invention does not cause pipe blockage or gas backflow due to high-temperature sintering, it effectively ensures the normal operation of the production process.

[0072] Furthermore, in this embodiment of the invention, a three-dimensional electromagnetic field model is generated based on the modeling of the biomass pyrolysis reactor. By predicting the temperature field distribution and electromagnetic field strength of each cavity in the reactor, the predicted dielectric properties of the absorbing coating are obtained. Thus, the actual effect of the absorbing coating in shielding microwaves within the reactor can be obtained based on the predicted values. Next, the purpose of setting up a microwave transition sub-cavity in this embodiment of the invention is to calculate the electromagnetic field strength within the cavity and then intuitively predict whether the microwave cutoff rate at the next time step meets the standard using numerical simulation. Then, the current dielectric properties of the absorbing coating are recorded. Based on this, when it is predicted that the microwave cutoff rate at the next time step will not meet the standard, the microwave power of the controllable microwave source is pre-adjusted to assist in adjusting the process conditions, thereby ensuring that the subsequent reaction cavity with combustion-supporting gas can completely shield or weaken microwaves to a safe electromagnetic field strength range.

[0073] Example 3

[0074] Based on Embodiment 1, the embodiments of the present invention may further include a processing device to automatically generate power adjustment commands and speed adjustment commands, so as to avoid the microwave absorbing coating from not completely blocking the microwaves and causing the microwaves to leak into the reaction cavity.

[0075] The processing device in this embodiment of the invention may specifically include:

[0076] The model calculation unit is used to calculate the simulation results of the three-dimensional electromagnetic field model according to the preset input parameters with a preset time step as the calculation period. The simulation results include the predicted values ​​of the temperature field distribution and the predicted values ​​of the electromagnetic field strength of each cavity after one time step. The three-dimensional electromagnetic field model is generated and meshed based on the biomass pyrolysis reactor. The input parameters include the current microwave frequency and current microwave power of each controllable microwave source, the dielectric constant and feed rate of the material, the current dielectric properties of the absorbing coating, and the mathematical model of the dielectric properties of the absorbing coating with frequency and temperature.

[0077] The dielectric property calculation unit is used to calculate the predicted dielectric properties of the microwave absorbing coating in the microwave absorbing cavity based on the predicted temperature field distribution and the input parameters.

[0078] An electromagnetic field strength calculation unit is used to calculate the predicted electromagnetic field strength correction value in the reaction cavity based on the predicted electromagnetic field strength estimate of each cavity and the predicted dielectric properties.

[0079] The power adjustment command unit is used to determine whether the reaction cavity contains an out-of-standard grid exceeding a preset threshold after one time step based on the predicted electromagnetic field strength correction value. If so, the current microwave power of the controllable microwave source is reduced according to a preset rule and returned to the model calculation unit; if not, a microwave power adjustment command for the controllable microwave source corresponding to the out-of-standard grid is generated with the current microwave power as the target microwave power.

[0080] It should be noted that the processing device in the embodiments of the present invention can be implemented by software programs, that is, its specific functions can be implemented through virtual devices.

[0081] The specific implementation steps of the software program used to implement the processing device can be referred to the control method of the vertical moving bed biomass pyrolysis reactor in Embodiment 2. Since the technical features of the processing device in this embodiment correspond one-to-one with the technical features of the control method of the vertical moving bed biomass pyrolysis reactor in Embodiment 2, and the technical effects achieved are the same, it will not be described again here.

[0082] Example 4

[0083] Corresponding to the method embodiment (i.e., Embodiment 2), this embodiment of the invention also provides a control device for a vertical moving bed biomass pyrolysis 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.

[0084] An example diagram of the hardware structure block diagram of the control equipment for the vertical moving bed biomass pyrolysis reactor provided in this application embodiment is shown below. Figure 3 As shown, it may include:

[0085] Processor 1, communication interface 2, memory 3, and communication bus 4;

[0086] The processor 1, communication interface 2, and memory 3 communicate with each other via communication bus 4.

[0087] Optionally, communication interface 2 can be an interface of a communication module, such as the interface of a GSM module;

[0088] 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.

[0089] Memory 3 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0090] Specifically, processor 1 is used to execute the computer program stored in memory 3 to perform the following steps:

[0091] S11. Using a preset time step as the calculation period, the simulation results of the three-dimensional electromagnetic field model are calculated based on preset input parameters. The simulation results include the predicted temperature field distribution and electromagnetic field strength of each cavity after one time step. The three-dimensional electromagnetic field model is generated and meshed based on the biomass pyrolysis reactor. The input parameters include the current microwave frequency and current microwave power of each controllable microwave source, the dielectric constant and feed rate of the material, the current dielectric properties of the absorbing coating, and the mathematical model of the dielectric properties of the absorbing coating with frequency and temperature.

[0092] S12. Calculate the predicted dielectric properties of the microwave absorbing coating in the microwave absorbing cavity based on the predicted temperature field distribution and the input parameters.

[0093] S13. Calculate the predicted electromagnetic field strength correction value in the reaction cavity based on the predicted electromagnetic field strength estimate and the predicted dielectric properties of each cavity.

[0094] S14. Based on the predicted electromagnetic field strength correction value, determine whether the reaction cavity contains an out-of-standard grid exceeding a preset threshold after one time step. If yes, reduce the current microwave power of the controllable microwave source according to the preset rule and return to step S11; if no, generate a microwave power adjustment command for the controllable microwave source corresponding to the out-of-standard grid with the current microwave power as the target microwave power.

[0095] 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 vertical moving bed biomass pyrolysis reactor provided in the embodiments of the present invention.

[0096] Example 5

[0097] 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:

[0098] S11. Using a preset time step as the calculation period, the simulation results of the three-dimensional electromagnetic field model are calculated based on preset input parameters. The simulation results include the predicted temperature field distribution and electromagnetic field strength of each cavity after one time step. The three-dimensional electromagnetic field model is generated and meshed based on the biomass pyrolysis reactor. The input parameters include the current microwave frequency and current microwave power of each controllable microwave source, the dielectric constant and feed rate of the material, the current dielectric properties of the absorbing coating, and the mathematical model of the dielectric properties of the absorbing coating with frequency and temperature.

[0099] S12. Calculate the predicted dielectric properties of the microwave absorbing coating in the microwave absorbing cavity based on the predicted temperature field distribution and the input parameters.

[0100] S13. Calculate the predicted electromagnetic field strength correction value in the reaction cavity based on the predicted electromagnetic field strength estimate and the predicted dielectric properties of each cavity.

[0101] S14. Based on the predicted electromagnetic field strength correction value, determine whether the reaction cavity contains an out-of-standard grid exceeding a preset threshold after one time step. If yes, reduce the current microwave power of the controllable microwave source according to the preset rule and return to step S11; if no, generate a microwave power adjustment command for the controllable microwave source corresponding to the out-of-standard grid with the current microwave power as the target microwave power.

[0102] Optionally, the refined and extended functions of the program can be found in the description above.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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 vertical moving bed biomass pyrolysis reactor, characterized in that, It includes a microwave heating device, a vertical moving bed, a control device, and a processing device; The microwave heating device includes a feed screw shaft, a microwave heating cavity, and a microwave generator equipped with multiple controllable microwave sources; the feed screw shaft conveys material through a tubular reactor in the microwave heating cavity for heating before it falls into the vertical moving bed; The vertical moving bed includes a microwave absorption cavity at the top and a reaction cavity at the bottom; the microwave absorption cavity is provided with multiple trays coated with microwave absorbing coatings; the trays are used to absorb residual electromagnetic waves; The control device executes the controllable microwave source and / or the feed screw shaft control actions according to the power adjustment command and / or speed adjustment command; The processing apparatus includes: The model calculation unit is used to calculate the simulation results of the three-dimensional electromagnetic field model according to the preset input parameters with a preset time step as the calculation period. The simulation results include the predicted values ​​of the temperature field distribution and the predicted values ​​of the electromagnetic field strength of each cavity after one time step. The three-dimensional electromagnetic field model is generated and meshed based on the biomass pyrolysis reactor. The input parameters include the current microwave frequency and current microwave power of each controllable microwave source, the dielectric constant and feed rate of the material, the current dielectric properties of the absorbing coating, and the mathematical model of the dielectric properties of the absorbing coating with frequency and temperature. The dielectric property calculation unit is used to calculate the predicted dielectric properties of the microwave absorbing coating in the microwave absorbing cavity based on the predicted temperature field distribution and the input parameters. An electromagnetic field strength calculation unit is used to calculate the predicted electromagnetic field strength correction value in the reaction cavity based on the predicted electromagnetic field strength estimate of each cavity and the predicted dielectric properties. The power adjustment command unit is used to determine whether the reaction cavity contains an out-of-standard grid exceeding a preset threshold after one time step based on the predicted electromagnetic field strength correction value. If so, the current microwave power of the controllable microwave source is reduced according to a preset rule and returned to the model calculation unit; if not, a microwave power adjustment command for the controllable microwave source corresponding to the out-of-standard grid is generated with the current microwave power as the target microwave power.

2. The vertical moving bed biomass pyrolysis reactor according to claim 1, characterized in that, include: The feed screw shaft, positioned horizontally within the microwave heating cavity, includes helical blades for propelling the material. The blade spacing of the spiral blades is set to gradually decrease from the driving end to the end.

3. The vertical moving bed biomass pyrolysis reactor according to claim 2, characterized in that, Also includes: The connection between the microwave absorption cavity and the reaction cavity serves as a throat area, and is equipped with a gas-supporting interface.

4. The vertical moving bed biomass pyrolysis reactor according to claim 3, characterized in that, include: The multiple trays are arranged in upper and lower layers and tilted downwards.

5. The vertical moving bed biomass pyrolysis reactor according to claim 4, characterized in that, include: The edge of the tray extends beyond the center point of the cross-section of the reaction chamber.

6. The vertical moving bed biomass pyrolysis reactor according to claim 5, characterized in that, include: The shape of the tower plate is an arc.

7. The vertical moving bed biomass pyrolysis reactor according to claim 2, characterized in that, include: The feed screw shaft and the drive motor are detachably connected.

8. The vertical moving bed biomass pyrolysis reactor according to claim 7, characterized in that, include: The feed screw shaft can be made of graphite composite material or metal material.

9. The vertical moving bed biomass pyrolysis reactor according to claim 1, characterized in that, The materials of the absorbing coating include: One or more of the following: stony ferrite, SiC ceramic, retinol Schiff base, retinol Schiff base complex, carbonyl iron powder, carbonyl nickel powder, fiber, nickel fiber, cobalt fiber and alloy fiber.

10. The vertical moving bed biomass pyrolysis reactor according to claim 9, characterized in that, include: The microwave absorbing coating is made of SiC ceramic.

11. The vertical moving bed biomass pyrolysis reactor according to claim 10, characterized in that, include: The thickness of the microwave absorbing coating ranges from 100 to 800 g / L.

12. The vertical moving bed biomass pyrolysis reactor according to claim 3, characterized in that, Also includes: The throat region is equipped with a microwave field strength detector, which generates a control command to blow the fuse of the microwave generator and terminate the transmission of the combustion-supporting gas when the residual electromagnetic wave in the throat region exceeds a preset intensity.

13. A control method for a vertical moving bed biomass pyrolysis reactor, used to control the biomass pyrolysis reactor as described in any one of claims 1 to 12, characterized in that, include: S11. Using a preset time step as the calculation period, calculate the simulation results of the three-dimensional electromagnetic field model according to the preset input parameters. The simulation results include the predicted values ​​of the temperature field distribution and the predicted values ​​of the electromagnetic field strength of each cavity after one time step. The three-dimensional electromagnetic field model is generated and meshed based on the biomass pyrolysis reactor model; the input parameters include the current microwave frequency and current microwave power of each controllable microwave source, the dielectric constant of the material, the feed rate, the current dielectric properties of the absorbing coating, and a mathematical model of the dielectric properties of the absorbing coating as a function of frequency and temperature. S12. Calculate the predicted dielectric properties of the microwave absorbing coating in the microwave absorbing cavity based on the predicted temperature field distribution and the input parameters. S13. Calculate the predicted electromagnetic field strength correction value in the reaction cavity based on the predicted electromagnetic field strength estimate and the predicted dielectric properties of each cavity. S14. Based on the predicted electromagnetic field strength correction value, determine whether the reaction cavity contains an out-of-standard grid exceeding a preset threshold after one time step. If yes, reduce the current microwave power of the controllable microwave source according to the preset rule and return to step S11; if no, generate a microwave power adjustment command for the controllable microwave source corresponding to the out-of-standard grid with the current microwave power as the target microwave power.

14. A control device for a vertical moving bed biomass pyrolysis reactor, characterized in that, include: Memory, used to store computer programs; A processor is used to invoke and execute the computer program to implement the control method steps of the vertical moving bed biomass pyrolysis reactor as described in claim 13.

15. A storage medium, characterized in that, Includes software programs adapted for execution by a processor of the control method steps of the vertical moving bed biomass pyrolysis reactor as described in claim 13.

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