Intelligent control system of multi-hot blast furnace cascade heat supply pyrolysis device

Abstract

This invention discloses an intelligent control system for a multi-hot blast furnace cascade heating pyrolysis device, relating to the field of organic pyrolysis technology. The intelligent control system includes a pyrolysis furnace body sequentially divided into a preheating section, a main pyrolysis section, and a deep pyrolysis section along the material flow direction; three heating groups consisting of four hot blast furnaces; a temperature detection unit; and a control system. The control system is equipped with a multivariable decoupling control module. This module contains a decoupling matrix obtained by inverting the gain matrix measured through step response experiments. The actual control signal output to each hot blast furnace is the decoupling matrix multiplied by a feedback correction vector, thereby eliminating the coupling influence between the three temperature sections. This invention can effectively suppress thermal interference between multiple hot blast furnaces, making the three temperature sections independent, stable, and controllable, providing a foundation for subsequent cascade regulation and significantly improving pyrolysis efficiency and product quality.

Description

Technical Field

[0001] This application relates to the field of organic thermal pyrolysis technology, and more specifically, to an intelligent control system for a multi-hot blast furnace cascade thermal pyrolysis device. Background Technology

[0002] Thermopyrolysis technology is an effective method to convert organic waste such as waste plastics, waste tires, and oil sludge into fuel oil, combustible gas, and solid carbon. During the pyrolysis process, the molten material needs to undergo a chain-breaking reaction at high temperature. A hot blast furnace is usually used to supply heat to the pyrolysis furnace to maintain the reaction temperature.

[0003] For pyrolysis systems using multiple hot blast stoves, theoretically, different areas of the pyrolysis furnace can be heated separately to achieve segmented temperature control. However, since multiple hot blast stoves share the same pyrolysis furnace cavity, the heat output of each hot blast stove not only affects its own area but also influences adjacent areas through flue gas flow. Existing control methods typically set a fixed target temperature for each hot blast stove without considering the coupling effect of the overall temperature field inside the furnace. For example, increasing the heat output of the front-end hot blast stove will raise the temperature of the entire front section of the furnace, forcing the rear hot blast stoves to adjust in the opposite direction, causing repeated oscillations and making it impossible to stably form the gradient curves required for the front, middle, and rear sections. This mutual interference between hot blast stoves severely restricts the accuracy of the stepwise control of the pyrolysis temperature, leading to unstable pyrolysis reaction, low oil production, and easy local coking.

[0004] Therefore, it is necessary for the inventors to design a new intelligent control system for a multi-hot blast furnace cascade heating pyrolysis device to overcome the above problems. Summary of the Invention

[0005] The main objective of this application is to provide an intelligent control system for a multi-hot blast furnace cascade heating pyrolysis device, which aims to solve the technical problem that when multiple hot blast furnaces share the same pyrolysis furnace cavity, the heat output of each hot blast furnace is coupled and interferes with each other, resulting in the inability to stably form the required temperature gradient.

[0006] To achieve the above objectives, this application provides an intelligent control system for a multi-hot blast stove cascade heating pyrolysis device, including... The pyrolysis furnace body is divided into a preheating section, a main pyrolysis section and a deep pyrolysis section along the material flow direction. Three heating units are used to supply heat to the preheating section, the main pyrolysis section and the deep pyrolysis section respectively; The temperature detection unit includes at least a first temperature sensor T1, a second temperature sensor T2, and a third temperature sensor T3 respectively disposed in the preheating section, the main pyrolysis section, and the deep pyrolysis section; A control system, the control system including a multivariable decoupling control module; The multivariable decoupling control module includes three independent PID controllers, which output feedback correction amounts based on the temperature deviations of the preheating section, the main pyrolysis section, and the deep pyrolysis section, respectively. The multivariable decoupling control module has a built-in decoupling matrix D, which is obtained by inverting the gain matrix G obtained by step response experiment of the system. The actual control signal output to each of the heating groups is the decoupling matrix D multiplied by the feedback correction vector, in order to eliminate the temperature coupling effect between the preheating section, the main pyrolysis section and the deep pyrolysis section.

[0007] Preferably, the method for measuring the gain matrix G is as follows: A step change is applied to the heating group corresponding to the preheating section, the main pyrolysis section, and the deep pyrolysis section, respectively; the temperature response amplitudes of the preheating section, the main pyrolysis section, and the deep pyrolysis section are recorded, forming the following matrix relationship: ; Wherein, ΔV1, ΔV2 and ΔV3 are the valve opening changes of the heating group corresponding to the preheating section, the main pyrolysis section and the deep pyrolysis section, respectively; ΔT1, ΔT2, and ΔT3 are the temperature changes in the preheating section, the main pyrolysis section, and the deep pyrolysis section, respectively. g 11 g 12 and g 13 These represent the influence coefficients of the three heating group opening changes on the preheating section temperature, respectively. g 21 g 22 and g 23 These represent the influence coefficients of the three heating group opening degree changes on the temperature of the main pyrolysis section, respectively. g 31 g 32 and g 33 These represent the influence coefficients of the three heating group opening changes on the temperature of the deep pyrolysis section.

[0008] Preferably, the control system further includes a tiered temperature setting module; The stepped temperature setting module uses the target temperature of the main pyrolysis section as a reference, sets the target temperature of the preheating section to be lower than the target temperature of the main pyrolysis section by a first temperature difference value, and sets the target temperature of the deep pyrolysis section to be higher than the target temperature of the main pyrolysis section by a second temperature difference value. The control system controls the output heat of the three heating groups according to the deviation between the real-time temperature of each section and the corresponding target temperature, so that a stable temperature gradient is formed in the pyrolysis furnace, which gradually increases from the preheating section through the main pyrolysis section to the deep pyrolysis section.

[0009] Preferably, the three heating groups are two first heating groups and one second heating group, the two first heating groups include a first hot air furnace and a fourth hot air furnace, and the second heating group includes a second hot air furnace and a third hot air furnace; The flue gas outlet of the first hot air furnace is connected to the preheating section and supplies heat only to the preheating section; The flue gas outlets of the second hot blast stove and the third hot blast stove are both connected to the main pyrolysis section and jointly supply heat to the main pyrolysis section; The flue gas outlet of the fourth hot blast stove is connected to the deep pyrolysis section and supplies heat only to the deep pyrolysis section.

[0010] Preferably, the temperature detection unit further includes an upstream temperature sensor located upstream of the main pyrolysis section and a downstream temperature sensor located downstream of the main pyrolysis section; the control system also includes a distribution and coordination module. The allocation and coordination module detects the upstream temperature T2u and the downstream temperature T2d in real time. Based on the temperature deviation between the upstream and downstream, the distribution coefficient α = u2 / (u2+u3) of the second hot blast stove and the third hot blast stove is dynamically adjusted, where u2 and u3 are the valve openings of the second hot blast stove and the third hot blast stove, respectively, and the total opening V2 = u2+u3 is determined by the multivariable decoupling control module, u2 = α·V2, u3 = (1-α)·V2; The allocation and coordination module optimizes α in real time with the goal of minimizing the lateral temperature difference |T2u-T2d|.

[0011] Preferably, the coupling gain g in the decoupling matrix D of the multivariable decoupling control module is... 12 and g 32 Online correction based on allocation coefficient α: ; Where k 12 and k 32 The correction coefficients, calibrated for the experiment, are obtained by measuring the rate of change of coupling gain under the first allocation coefficient (α1=0.5) and the second allocation coefficient (α2≠0.5), respectively, with a typical value range of 0.2 to 0.5. The coefficient representing the actual effective influence of the total opening change of the second and third hot blast stoves on the temperature of the preheating section is the coupling gain g. 12 The value after correction by the allocation coefficient α; This is the actual effective influence coefficient of the total opening degree change of the second and third hot blast stoves on the temperature of the deep pyrolysis section; it is the coefficient of the coupling gain g. 32 The value after adjustment by the allocation coefficient α.

[0012] Preferably, when a fault is detected in the second or third hot blast stove, the control system automatically sets the valve opening of the faulty stove to zero, forces the allocation coefficient α of the non-faulty stove to 1 or 0, and switches to the pre-stored single-stove operation of the gain matrix G to maintain decoupled control.

[0013] Preferably, the control system further includes a master-slave gradient tracking mode; Using the actual temperature of the main pyrolysis section as the reference, the target temperature of the preheating section and the target temperature of the deep pyrolysis section are dynamically adjusted according to the actual temperature of the main pyrolysis section at a set rate of change. The rate of change is 0.1–0.5 °C / min to maintain a constant temperature difference between the three sections.

[0014] Preferably, the first temperature difference is 50-100℃, and the second temperature difference is 30-80℃.

[0015] Preferably, it also includes a pressure detection unit and an interlocking protection module; The pressure detection unit includes at least a first pressure sensor, a second pressure sensor, and a third pressure sensor disposed in the preheating section, the main pyrolysis section, and the deep pyrolysis section; The interlock protection module receives signals from each pressure sensor. When any pressure value exceeds the safety threshold, it automatically performs operations such as reducing the speed of the screw conveyor, stopping the material, or opening the emergency pressure relief valve.

[0016] The intelligent control system for a multi-hot blast stove cascade heating pyrolysis device provided by this invention has the following advantages compared with the prior art: Through the above technical solution, the multivariable decoupling control module uses the decoupling matrix D to cancel out the coupling effects between the three heating groups, so that the output of each hot blast stove only affects the temperature of its corresponding section, while the temperature effect on other sections is greatly suppressed. This solves the temperature oscillation problem caused by mutual interference of multiple hot blast stoves, and enables the temperatures of the preheating section, main pyrolysis section and deep pyrolysis section to be independently and stably controlled near the target value. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application and to make other features, objects and advantages of this application more apparent. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application.

[0018] In the attached diagram: Figure 1 This is a schematic diagram of the external structure of the pyrolysis furnace body in this invention; Figure 2 This is a schematic diagram of the internal structure of the pyrolysis furnace body in this invention. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0020] It should be noted that the terms "first," "second," etc., used in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be used interchangeably where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0021] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0022] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in certain circumstances to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0023] In addition, the term "multiple" should mean two or more.

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] Example 1, as Figure 1 and Figure 2As shown in the figure, the intelligent control system of the multi-hot blast furnace cascade heating pyrolysis device provided in this embodiment includes a pyrolysis furnace body, four hot blast furnaces, a temperature detection unit, a pressure detection unit, and a control system. The total length of the pyrolysis furnace body is 12m, which is divided into a 3m long preheating section, a 6m long main pyrolysis section, and a 3m long deep pyrolysis section along the material flow direction. The flue gas outlet of the first hot blast furnace is connected to the preheating section and only supplies heat to the preheating section. The flue gas outlets of the second and third hot blast furnaces are both connected to the main pyrolysis section and both supply heat to the main pyrolysis section. The flue gas outlet of the fourth hot blast furnace is connected to the deep pyrolysis section and only supplies heat to the deep pyrolysis section.

[0026] The temperature detection unit includes a first temperature sensor T1 located in the preheating section, a second temperature sensor T2 located in the middle of the main pyrolysis section, and a third temperature sensor T3 located in the deep pyrolysis section. In addition, an upstream temperature sensor T2u is located near the inlet of the second hot blast furnace in the main pyrolysis section, and a downstream temperature sensor T2d is located near the inlet of the third hot blast furnace. T2 is used to represent the overall temperature of the main pyrolysis section and serves as the feedback quantity for the PID in the multivariable decoupling control module to control the target temperature T2_sp of the main pyrolysis section. T2u and T2d are used to allocate and coordinate the module to monitor the transverse temperature difference. The numerical relationship between the three is T2≈(T2u+T2d) / 2 in actual operation. However, due to the change of the allocation coefficient α, T2 is calculated independently and does not depend on the average value calculation.

[0027] The pressure detection unit includes a first pressure sensor P1 located in the preheating section, a second pressure sensor P2 located in the main pyrolysis section, and a third pressure sensor P3 located in the deep pyrolysis section. The control system adopts a DCS and integrates a stepped temperature setting module, a multivariable decoupling control module, a distribution coordination module, a master-slave gradient tracking module, and an interlock protection module.

[0028] In this embodiment, the material processed is molten waste plastic with a processing capacity of 500 kg / h. The operator sets the target temperature of the main pyrolysis section, T2_sp, to 500℃ via the human-machine interface. The stepped temperature setting module automatically calculates the target temperature of the preheating section, T1_sp = T2_sp - ΔT1, and the target temperature of the deep pyrolysis section, T3_sp = T2_sp + ΔT2. The first temperature difference, ΔT1, is set to 70℃, and the second temperature difference, ΔT2, is set to 50℃, i.e., T1_sp = 430℃ and T3_sp = 550℃. This setting solves the problem that a single temperature cannot meet the needs of different thermochemical stages. The 430℃ preheating section ensures good material flowability and avoids coking and blockage. The 500℃ main pyrolysis section ensures that macromolecules are fully broken down, improving oil and gas yield. The 550℃ deep pyrolysis section further reduces the oil content of residual carbon, thus forming a stable temperature gradient that gradually increases from the preheating section through the main pyrolysis section to the deep pyrolysis section.

[0029] After the control system starts, it reads real-time data: T1 = 445℃, T2 = 490℃, T3 = 540℃. The temperature deviations of the three segments are: e1 = T1 - T1_sp = 445 - 430 = +15℃, meaning the preheating section is overheated. e2 = T2 - T2_sp = 490 - 500 = -10℃, meaning the main pyrolysis section is underheated. e3=T3-T3_sp=540-550=-10℃, meaning the deep cracking section is underheated.

[0030] The multivariable decoupling control module includes three independent PID controllers, each outputting a feedback correction based on the aforementioned deviation. It employs negative feedback logic: when overheating occurs, the valve opening is reduced (resulting in a negative correction); when underheating occurs, the valve opening is increased (resulting in a positive correction). Simple proportional control is used, with the proportional coefficient set to K. p =0.2% / ℃, that is ΔV1_fb=K p e1 = 0.2 × 12 = 3.0% ΔV2_fb=K p e2 = 0.2 × (-10) = -2.0%, ΔV3_fb=K p e3 = 0.2 × (-10) = -2.0%.

[0031] The multivariable decoupling control module has a built-in decoupling matrix D. The decoupling matrix D is obtained by inverting the gain matrix G obtained from the step response experiment of the system. The measurement method of the gain matrix G is as follows: under the stable operation state of the system, a 10% step change in valve opening is applied to the total output of the first hot blast stove, the second hot blast stove, the third hot blast stove, and the fourth hot blast stove, respectively. The steady-state temperature response amplitude of the preheating section, the main pyrolysis section, and the deep pyrolysis section is recorded, forming the following matrix relationship: ; Among them, ΔV1, ΔV2 and ΔV3 are the valve opening changes of the heating group corresponding to the preheating section, the main pyrolysis section and the deep pyrolysis section, respectively; ΔT1, ΔT2, and ΔT3 represent the temperature changes in the preheating section, the main pyrolysis section, and the deep pyrolysis section, respectively. g 11 g 12 and g 13 These represent the influence coefficients of the three heating group opening degree changes on the preheating section temperature, respectively. g 21 g 22 and g 23 These represent the influence coefficients of the three heating group opening degree changes on the temperature of the main pyrolysis section, respectively. g 31 g32 and g 33 These represent the influence coefficients of the three heating group opening degree changes on the temperature of the deep cracking section.

[0032] The actual measurement results in this embodiment are as follows: ; Decoupling matrix D=G -1 The calculation yielded the following: ; The actual control signal output to each hot blast stove (i.e., the opening correction amount) is the decoupling matrix D multiplied by the feedback correction vector: ; ΔV1_ is calculated cmd =-4.24%, ΔV2_ cmd =+3.52%, ΔV3_ cmd =+2.20%, In this embodiment, the opening degree of the first hot blast stove valve is 35%, the total opening degree of the second and third hot blast stove valves is 64%, and the opening degree of the fourth hot blast stove valve is 43%. After correction, the opening degree of the first hot blast stove valve is 30.76%, the total opening degree of the second and third hot blast stove valves is 67.52%, and the opening degree of the fourth hot blast stove valve is 45.20%. This invention eliminates the coupling effect between the three temperature segments through a multivariable decoupling control module and a decoupling matrix, thereby reducing the temperature fluctuation range of the three segments.

[0033] The allocation and coordination module reads T2u and T2d once per second, measuring the current T2u = 495℃ and T2d = 485℃, with a lateral temperature difference of |T2u - T2d| = 10℃. To minimize this lateral temperature difference, the allocation coefficient α = u2 / (u2 + u3) is dynamically adjusted using proportional control. If T2u > T2d (i.e., upstream overheating), α is decreased, meaning the opening of the second hot blast stove is reduced and the opening of the third hot blast stove is increased; conversely, α is increased. The adjustment step size is 0.01, until the lateral temperature difference is ≤ 2℃. Initially, α = 0.5. After several adjustments, α stabilizes at 0.45. At this point, the total opening of the valves of the second and third hot blast stoves is 67.52%. Therefore, the actual openings of the valves of the second and third hot blast stoves are u2 = α·V2_ cmd =0.45×67.52%=30.38%, u3=(1-α)·V2_ cmd =0.55×67.52%=37.14%.

[0034] Since α deviates from 0.5, the coupling strength of the second heating group to the preheating section and the depth section changes, and the coupling gain needs to be corrected online. The experimentally calibrated correction factor k is used. 12 =0.3, k 32=0.3, corrected according to the following formula: ; The control system substitutes the effective coupling gain into the gain matrix G and recalculates the decoupling matrix D for subsequent control cycles to ensure decoupling accuracy. This invention dynamically adjusts the load distribution of the second and third hot blast stoves through the allocation coordination module, thereby reducing the transverse temperature difference in the main pyrolysis section and significantly improving the uniformity of pyrolysis products. At the same time, the coupling gain in the decoupling matrix D is corrected online according to the allocation coefficient α, ensuring that the decoupling control remains optimal when the allocation changes.

[0035] The master-slave gradient tracking module uses the actual temperature T2 of the main pyrolysis section as the tracking benchmark. The target temperatures of the preheating section and the deep pyrolysis section are dynamically adjusted with respect to T2 at a set rate of change. In this embodiment, the rate of change is set to 0.2℃ / min to maintain a constant temperature difference between the three sections. When the material properties change and the optimal pyrolysis temperature drifts from 500℃ to 525℃, the actual temperature T2 of the main pyrolysis section gradually increases. T1_sp and T3_sp are adjusted to 455℃ and 575℃ respectively at a rate of 0.2℃ / min, always maintaining a temperature difference relationship of ΔT1=70℃ and ΔT2=50℃. Through the master-slave gradient tracking module, the target temperatures of the preheating section and the deep pyrolysis section are dynamically adjusted with respect to the actual temperature of the main pyrolysis section, maintaining a constant temperature difference relationship and improving the system's adaptability to different material properties.

[0036] When the second hot blast stove fails and shuts down, the control system immediately forces α to 0, that is, the actual opening degree u2 of the valve of the second hot blast stove is 0, and the third hot blast stove takes on the full total opening degree V2. Similarly, if the third hot blast stove fails, α is forced to 1. This method can reduce the temperature fluctuation of the main cracking section when a failure occurs, without interrupting production.

[0037] The interlocking protection module receives signals from each pressure sensor and automatically executes a safety operation when any pressure value exceeds a safety threshold. In this embodiment, the safety threshold is set to P1_ max =30kPa, P2_ max =60kPa, P3_ max =40kPa. When the pressure in the main pyrolysis section suddenly rises from 5kPa to 65kPa due to poor slag discharge, exceeding 60kPa, the interlock protection module will be executed immediately. First, the speed of the screw conveyor will be reduced from 500kg / h to 250kg / h. If the pressure in the main pyrolysis section does not decrease after 10 seconds, the feeding will be stopped and the emergency pressure relief valve of the pyrolysis furnace will be opened. At the same time, the gas supply to all hot blast stoves will be cut off. The response time of this interlock protection is less than 1 second, which is used to eliminate the risk of overpressure explosion.

[0038] In summary, this invention utilizes a three-stage pyrolysis furnace and four hot blast stoves for differentiated heating, along with a tiered temperature setting module, to create a stable temperature gradient within the pyrolysis furnace that gradually increases from the preheating section through the main pyrolysis section to the deep pyrolysis section. This precisely matches the heat requirements of each stage of material preheating, main pyrolysis, and deep pyrolysis, eliminating problems such as uneven temperature distribution, localized coking, and incomplete pyrolysis. Experiments have shown that there is no coking in the preheating section, the oil yield in the main pyrolysis section is increased, and the oil content in the carbon residue in the deep pyrolysis section is reduced.

[0039] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An intelligent control system for a multi-hot blast furnace cascade heating pyrolysis device, characterized in that, include: The pyrolysis furnace body is divided into a preheating section, a main pyrolysis section and a deep pyrolysis section along the material flow direction. Three heating groups are used to supply heat to the preheating section, the main pyrolysis section, and the deep pyrolysis section, respectively. The three heating groups are two first heating groups and one second heating group. The two first heating groups include a first hot air furnace and a fourth hot air furnace. The second heating group includes a second hot air furnace and a third hot air furnace. The flue gas outlet of the first hot air furnace is connected to the preheating section and supplies heat only to the preheating section. The flue gas outlets of the second hot air furnace and the third hot air furnace are both connected to the main pyrolysis section and supply heat to the main pyrolysis section together. The flue gas outlet of the fourth hot air furnace is connected to the deep pyrolysis section and supplies heat only to the deep pyrolysis section. The temperature detection unit includes at least a first temperature sensor (T1), a second temperature sensor (T2), and a third temperature sensor (T3) respectively disposed in the preheating section, the main pyrolysis section, and the deep pyrolysis section. The temperature detection unit also includes an upstream temperature sensor disposed upstream of the main pyrolysis section and a downstream temperature sensor disposed downstream of the main pyrolysis section. A control system, comprising a multivariable decoupling control module and an allocation and coordination module; The multivariable decoupling control module includes three independent PID controllers, which output feedback correction amounts based on the temperature deviations of the preheating section, the main pyrolysis section, and the deep pyrolysis section, respectively. The multivariable decoupling control module has a built-in decoupling matrix D, which is obtained by inverting the gain matrix G obtained by step response experiment of the system. The measurement method of the gain matrix G is as follows: apply a step change to the heating group corresponding to the preheating section, the main pyrolysis section and the deep pyrolysis section respectively, and record the temperature response amplitude of the preheating section, the main pyrolysis section and the deep pyrolysis section. The actual control signal output to each of the heating groups is the decoupling matrix D multiplied by the feedback correction vector, so as to eliminate the temperature coupling effect between the preheating section, the main pyrolysis section and the deep pyrolysis section; The allocation and coordination module detects the upstream temperature T2u and the downstream temperature T2d in real time. Based on the deviation between the upstream and downstream temperatures, it dynamically adjusts the allocation coefficient α = u2 / (u2+u3) between the second hot blast stove and the third hot blast stove, where u2 and u3 are the valve openings of the second hot blast stove and the third hot blast stove, respectively. The total opening V2 = u2+u3 is determined by the multivariable decoupling control module, u2 = α·V2, u3 = (1-α)·V2. The allocation and coordination module optimizes α in real time with the goal of minimizing the transverse temperature difference |T2u-T2d|. The control system substitutes the effective coupling gain into the gain matrix G and recalculates the decoupling matrix D for subsequent control cycles to ensure decoupling accuracy. The load distribution of the second hot blast stove and the third hot blast stove is dynamically adjusted through the allocation coordination module to reduce the transverse temperature difference of the main pyrolysis section. At the same time, the coupling gain in the decoupling matrix D is corrected online according to the allocation coefficient α to ensure that the decoupling control remains optimal when the allocation changes.

2. The intelligent control system of the multi-hot blast furnace cascade heating pyrolysis device according to claim 1, characterized in that, The gain matrix G forms the following matrix relationship: ； Wherein, ΔV1, ΔV2 and ΔV3 are the valve opening changes of the heating group corresponding to the preheating section, the main pyrolysis section and the deep pyrolysis section, respectively; ΔT1, ΔT2, and ΔT3 are the temperature changes in the preheating section, the main pyrolysis section, and the deep pyrolysis section, respectively. g 11 g 12 and g 13 These represent the influence coefficients of the three heating group opening changes on the preheating section temperature, respectively. g 21 g 22 and g 23 These represent the influence coefficients of the three heating group opening degree changes on the temperature of the main pyrolysis section, respectively. g 31 g 32 and g 33 These represent the influence coefficients of the three heating group opening changes on the temperature of the deep pyrolysis section.

3. The intelligent control system for the multi-hot blast furnace cascade heating pyrolysis device according to claim 1, characterized in that, The control system also includes a cascade temperature setting module; The stepped temperature setting module uses the target temperature of the main pyrolysis section as a reference, sets the target temperature of the preheating section to be lower than the target temperature of the main pyrolysis section by a first temperature difference value, and sets the target temperature of the deep pyrolysis section to be higher than the target temperature of the main pyrolysis section by a second temperature difference value. The control system controls the output heat of the three heating groups according to the deviation between the real-time temperature of each section and the corresponding target temperature, so that a stable temperature gradient is formed in the pyrolysis furnace, which gradually increases from the preheating section through the main pyrolysis section to the deep pyrolysis section.

4. The intelligent control system of the multi-hot blast furnace cascade heating pyrolysis device according to claim 2, characterized in that, The coupling gain g in the decoupling matrix D of the multivariable decoupling control module 12 and g 32 Online correction based on allocation coefficient α: ； Where k 12 and k 32 The correction coefficients used for experimental calibration were obtained by measuring the rate of change of coupling gain under the first allocation coefficient (α1=0.5) and the second allocation coefficient (α2≠0.5), with typical values ​​ranging from 0.2 to 0.

5. geff 12 is the actual effective influence coefficient of the total opening degree change of the second and third hot blast stoves on the temperature of the preheating section; it is the coupling gain g 12 The value after correction by the allocation coefficient α; geff 32 is the actual effective influence coefficient of the total opening degree change of the second and third hot blast stoves on the temperature of the deep pyrolysis section. It is the coefficient of the coupling gain g. 32 The value after adjustment by the allocation coefficient α.

5. The intelligent control system of the multi-hot blast furnace cascade heating pyrolysis device according to claim 1, characterized in that, When a fault is detected in the second or third hot blast stove, the control system automatically sets the valve opening of the faulty stove to zero, forces the allocation coefficient α of the non-faulty stove to 1 or 0, and switches to the pre-stored single-stove operation gain matrix G to maintain decoupled control.

6. The intelligent control system of the multi-hot blast furnace cascade heating pyrolysis device according to claim 1, characterized in that, The control system also features a master-slave gradient tracking mode; Using the actual temperature of the main pyrolysis section as the reference, the target temperature of the preheating section and the target temperature of the deep pyrolysis section are dynamically adjusted according to the actual temperature of the main pyrolysis section at a set rate of change. The rate of change is 0.1–0.5 °C / min to maintain a constant temperature difference between the three sections.

7. The intelligent control system of the multi-hot blast furnace cascade heating pyrolysis device according to claim 3, characterized in that, The first temperature difference is 50-100℃, and the second temperature difference is 30-80℃.

8. The intelligent control system for the multi-hot blast furnace cascade heating pyrolysis device according to claim 1, characterized in that, It also includes a pressure detection unit and an interlock protection module; The pressure detection unit includes at least a first pressure sensor, a second pressure sensor, and a third pressure sensor disposed in the preheating section, the main pyrolysis section, and the deep pyrolysis section; The interlock protection module receives signals from each pressure sensor. When any pressure value exceeds the safety threshold, it automatically performs operations such as reducing the speed of the screw conveyor, stopping the material, or opening the emergency pressure relief valve.

Images