Carbon nanotube fluidized bed temperature cascade control system and method

Abstract

The invention relates to the technical field of carbon nanotube preparation, and provides a carbon nanotube fluidized bed temperature cascade control system and method, and the system comprises a main temperature cascade control subsystem and an auxiliary temperature cascade control subsystem which are composed of a stainless steel reactor, a reactor heating furnace body, a gas cabinet, a gas bag heating furnace body and the like. The main temperature cascade control subsystem forms closed-loop control through components such as a T reactor temperature control thermocouple and a TC main controller, so as to ensure that the basic temperature of the reactor is stable; and the auxiliary temperature cascade control subsystem controls the gas pocket heating furnace body through similar components so as to preheat gas to influence the temperature of the reactor. Feedforward control is further introduced into the system, a TC main controller collects temperature, voltage, flow and other data, predicts disturbance and adjusts a set value in advance, the heating power is adjusted through a reactor heating power regulator and an air pocket heating power regulator, and accurate control over the temperature of the reactor is achieved. According to the invention, the response speed and precision of temperature control are effectively improved, and the quality and stability of carbon nanotube production are guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of carbon nanotube preparation, and in particular to a temperature cascade control system and method for a carbon nanotube fluidized bed. Background Art

[0002] Fluidized bed is a commonly used reactor for gas phase reaction. When the reaction gas passes through the reactor, the catalytic particles are suspended by the airflow, and violently roll and flow in the reactor, showing a high degree of dynamic mixing. The contact area between the particles and the gas is greatly increased, which greatly increases the material transfer (oxidation, reactants, products, etc.) and heat exchange between gas and solid, which is conducive to fast and efficient chemical reactions or physical processes (drying, cooling, adsorption, etc.). It is an essential equipment for mass production of multi-walled carbon nanotubes.

[0003] In the existing carbon nanotube fluidized bed production process, a significant technical problem is the inaccurate temperature measurement. Specifically, the existing equipment generally adopts a single-loop conventional PID temperature control strategy, and only sets temperature measurement points on the outer wall of the reactor. Figure 4 . This temperature measurement method cannot truly reflect the temperature changes inside the reactor, because the temperature distribution inside the reactor may be extremely uneven due to various factors (such as gas cracking heat absorption, changes in chemical reaction rate, etc.). This inaccurate temperature measurement directly affects the accuracy of temperature control. When the process is subject to external disturbances (such as raw material changes, ambient temperature fluctuations, etc.), the temperature inside the reactor will fluctuate significantly. However, due to the improper location of the temperature measurement point, the control system cannot capture these changes in time, resulting in the temperature inside the reactor unable to quickly return to the preset process temperature, affecting the quality of the product and the stability of production.

[0004] Due to the large inertia and hysteresis of fluidized bed reactors, conventional PID controllers are difficult to achieve ideal control effects when facing temperature changes. This means that even if the temperature measurement is accurate, the control system may not be able to respond quickly to temperature changes due to the physical characteristics of the reactor, resulting in the accuracy and stability of temperature control being affected. In the actual production process, this is manifested as the system being unable to make immediate adjustments when the temperature in the reactor fluctuates due to process disturbances, the temperature recovery speed is slow, and even temperature overshoot or undershoot may occur. This not only directly reduces production efficiency, but may also damage the equipment due to long-term temperature fluctuations and increase maintenance costs. More seriously, this poor control effect and delayed system response will seriously affect the quality and consistency of the product, and have an adverse impact on the production and application of carbon nanotubes. In addition, the existing system mainly relies on feedback control and lacks a feedforward control mechanism to predict and compensate for potential disturbances, further limiting the system's ability to respond quickly to temperature changes. Summary of the invention

[0005] In order to solve the problems existing in the background technology, the present invention provides a carbon nanotube fluidized bed temperature cascade control system, which includes: a stainless steel reactor as the main equipment for chemical reaction; a reactor heating furnace wrapped outside the stainless steel reactor and heating the stainless steel reactor; a gas cabinet for storing and supplying gas required for the reaction; a gas bag heating furnace for preheating the gas; and further provided with:

[0006] The T reactor temperature control thermocouple is installed inside the stainless steel reactor to measure the temperature inside the stainless steel reactor in real time;

[0007] The TC main controller is a PLC controller with logic judgment function, which receives the temperature signal measured by the temperature control thermocouple of the T reactor and controls the operation of the system;

[0008] T1 reactor heating furnace thermocouple, installed on the reactor heating furnace to measure the furnace temperature;

[0009] The T1C reactor heating controller receives the temperature signal of the thermocouple of the T1 reactor heating furnace and the signal of the TC main controller, and generates control instructions;

[0010] The reactor heating power regulator is connected to the T1C reactor heating controller and adjusts the heating power output of the reactor heating furnace according to the instructions of the T1C reactor heating controller;

[0011] T2 gas bag heater thermocouple, installed on the gas bag heating furnace body, measures the temperature of the gas bag heating furnace body;

[0012] T2C gas bag heating controller receives the temperature signal of the thermocouple of T2 gas bag heater and the signal of TC main controller, and generates control instructions;

[0013] The gas bag heating power regulator is connected to the T2C gas bag heating controller and adjusts the heating power output of the gas bag heating furnace body according to the instructions of the T2C gas bag heating controller.

[0014] The system is equipped with a main temperature cascade control subsystem and a sub-temperature cascade control subsystem, where:

[0015] The main temperature cascade control subsystem includes a T reactor temperature control thermocouple, a TC main controller, a T1 reactor heating furnace body thermocouple, a T1C reactor heating controller, and a reactor heating power regulator; wherein: the T reactor temperature control thermocouple is connected to the TC main controller, the TC main controller is respectively connected to the T1 reactor heating furnace body thermocouple and the T1C reactor heating controller, and the T1C reactor heating controller is further connected to the reactor heating power regulator, forming the first closed-loop cascade control subsystem;

[0016] The auxiliary temperature cascade control subsystem includes a T reactor temperature control thermocouple, a TC main controller, a T2 gas bag heater thermocouple, a T2C gas bag heating controller, and a gas bag heating power regulator; wherein: the T reactor temperature control thermocouple is connected to the TC main controller, the TC main controller is respectively connected to the T2 gas bag heater thermocouple and the T2C gas bag heating controller, and the T2C gas bag heating controller is further connected to the gas bag heating power regulator to form a second closed-loop cascade control system.

[0017] A method for temperature control using a carbon nanotube fluidized bed temperature cascade control system is performed in the following steps:

[0018] S1, system startup, preset the temperature setting value SV1 of the main temperature cascade control system and the temperature setting value SV2 of the auxiliary temperature cascade control system;

[0019] The control process S2 of the main temperature cascade control subsystem and the control process S3 of the auxiliary temperature cascade control subsystem are carried out synchronously, and the specific process includes:

[0020] S21, T reactor temperature control thermocouple measures the temperature inside the stainless steel reactor in real time and transmits the temperature signal to the TC main controller.

[0021] S22. The TC main controller compares the received temperature signal with the preset process temperature to determine whether the current temperature deviates from the set value.

[0022] S23. If the temperature deviates from the set value, the TC main controller generates a corresponding control instruction to adjust the set value SV1 of the main temperature cascade control subsystem.

[0023] S24, T1 reactor heating furnace thermocouple measures furnace temperature and transmits the signal to T1C reactor heating controller.

[0024] S25, T1C controller receives the instruction of TC main controller and the signal of T1 thermocouple, generates control instruction, and adjusts the heating power of furnace body through reactor heating power regulator to adjust reactor temperature.

[0025] S31, T reactor temperature control thermocouple measures the temperature inside the stainless steel reactor in real time and transmits the temperature signal to the TC main controller.

[0026] S32. The TC main controller compares the received temperature signal with the preset process temperature to determine whether the current temperature deviates from the set value.

[0027] S33. If the temperature deviates from the set value, the TC main controller generates a corresponding control instruction to adjust the set value SV2 of the auxiliary temperature cascade control subsystem.

[0028] S34, T2 gas bag heater thermocouple measures the temperature of the gas bag heating furnace body and transmits the signal to the T2C gas bag heating controller.

[0029] S35, T2C controller receives the instruction of TC main controller and the signal of T2 thermocouple, generates control instruction, and adjusts the heating power of gas-drum heating furnace through gas-drum heating power regulator to preheat gas, thereby affecting reactor temperature.

[0030] Furthermore, the method further includes a feedforward control step S4, which is as follows:

[0031] S41, TC main controller continuously collects temperature data, grid voltage, and gas flow data from T reactor temperature control thermocouple, T1 reactor heating furnace thermocouple, and T2 gas bag heater thermocouple. The main controller processes and analyzes the collected data to identify the changing trends of temperature, grid voltage, and gas flow parameters, and predicts potential disturbances caused by fluctuations in grid voltage or changes in gas flow.

[0032] S42, TC main controller generates control instructions based on the predicted disturbance type and degree, and adjusts SV1 and SV2 in advance to deal with the impending disturbance.

[0033] S43, the TC main controller transmits the generated control instruction to the T1C reactor heating controller and the T2C gas bag heating controller, and the T1C reactor heating controller and the T2C gas bag heating controller adjust their respective heating power parameters according to the instruction.

[0034] The beneficial effects achieved by the present invention are:

[0035] The present invention innovatively designs a temperature cascade control system, including a main temperature cascade control subsystem and a secondary temperature cascade control subsystem, and designs corresponding control strategies, which significantly improves the response speed and regulation accuracy of the system. The system achieves fine regulation of the heating power through the coordinated work of a stainless steel reactor, a reactor heating furnace, a gas cabinet, a gas bag heating furnace, and multiple temperature controllers and power regulators, ensuring the constant and stable temperature inside the reactor.

[0036] The temperature cascade control system of the present invention adopts an advanced double-closed-loop cascade control strategy, that is, combining the main temperature cascade control subsystem and the auxiliary temperature cascade control subsystem to form an efficient and stable temperature control system. The main temperature cascade control subsystem focuses on maintaining the basic temperature platform of the reactor to ensure the stability of the overall temperature; while the auxiliary temperature cascade control subsystem further refines the adjustment to cope with more subtle temperature fluctuations. The two complement each other and jointly achieve precise control of the reactor temperature. In addition, the system also introduces a feedforward control mechanism. Through the continuous monitoring and analysis of temperature, grid voltage, gas flow and other data by the TC main controller, it can predict and respond to potential disturbance factors in advance, effectively reducing the impact of temperature fluctuations on the carbon nanotube preparation process, and further improving the stability and reliability of the system.

[0037] At the same time, the present invention installs a T reactor temperature control thermocouple inside the stainless steel reactor, changing the traditional practice of only setting temperature measuring points on the outer wall of the reactor, and directly monitoring the real-time temperature inside the reactor. Through the powerful processing capability of the TC main controller, the temperature data is quickly analyzed and converted into precise control instructions, so that the reactor can continue to operate under the optimal temperature conditions, providing a strong guarantee for the stability and reliability of the preparation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a structural diagram of the temperature cascade control system of the carbon nanotube fluidized bed of the present invention.

[0039] Figure 2 It is the control principle diagram of the main temperature control cascade control subsystem.

[0040] Figure 3 It is the control principle diagram of the auxiliary temperature control cascade control subsystem.

[0041] Figure 4 It is the principle diagram of temperature control of existing fluidized bed sheet circuit.

[0042] Numbers in the figure:

[0043] 1. Stainless steel reactor; 2. Reactor heating furnace body; 3. T reactor temperature control thermocouple; 4. TC main controller; 5. T1 reactor heating furnace body thermocouple; 6. T1C reactor heating controller; 7. Reactor heating power regulator; 8. T2 gas bag heater thermocouple; 9. T2C gas bag heating controller; 10. Gas bag heating power regulator; 11. Gas cabinet; 12. Gas bag heating furnace body. DETAILED DESCRIPTION

[0044] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention. In addition, the forms of the various structures recorded in the following embodiments are merely illustrative, and the present invention is not limited to the various structures recorded in the following embodiments. All other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0045] Reference Figure 1-Figure 4 The present invention provides a carbon nanotube fluidized bed temperature cascade control system, the composition structure of which includes:

[0046] Stainless steel reactor 1: As the main equipment for chemical reaction, it is the core part of the system, and other components are arranged around it.

[0047] Reactor heating furnace body 2: Wrapped outside the stainless steel reactor 1, heating the stainless steel reactor 1. Closely fit with the stainless steel reactor 1, providing the temperature environment required for the reaction through heating.

[0048] Gas cabinet 11: stores and supplies the gas required for the reaction. It is connected to the gas bag heating furnace body 12 through a pipeline to ensure that the gas can smoothly enter the heating and reaction process.

[0049] Gas bag heating furnace body 12: preheats the gas to improve the reaction efficiency. It is connected to the gas cabinet 11, receives the gas and preheats it; it is also connected to the gas bag heating controller and the heating power regulator, and receives control instructions to adjust the heating power.

[0050] T reactor temperature control thermocouple 3: installed inside the stainless steel reactor 1, real-time measurement of the temperature inside the reactor. Connected to the TC main controller 4, transmission of temperature signals.

[0051] T1 reactor heating furnace body thermocouple 5: installed on the reactor heating furnace body 2, measuring the furnace body temperature. Connected to T1C reactor heating controller 6, transmitting temperature signal.

[0052] T2 air bag heater thermocouple 8: installed on the air bag heating furnace body 12, measuring the temperature of the air bag heating furnace body 12. Connected to the T2C air bag heating controller 9 to transmit temperature signals.

[0053] TC main controller 4: It is a PLC controller with logic judgment function. It receives the temperature signal of T reactor temperature control thermocouple 3, and is connected with T1C reactor heating controller 6 and T2C air bag heating controller 9 to transmit control instructions.

[0054] T1C reactor heating controller 6: receives the temperature signal of T1 reactor heating furnace thermocouple 5 and the signal of TC main controller 4, generates control instructions, and is connected to reactor heating power regulator 7 to transmit control instructions.

[0055] T2C air bag heating controller 9: receives the temperature signal of T2 air bag heater thermocouple 8 and the signal of TC main controller 4, generates control instructions, and is connected to air bag heating power regulator 10 to transmit control instructions.

[0056] Reactor heating power regulator 7 and gas-drum heating power regulator 10: adjust the heating power output of the reactor heating furnace body 2 and the gas-drum heating furnace body 12 according to the instructions of the T1C reactor heating controller 6 and the T2C gas-drum heating controller 9 respectively.

[0057] The stainless steel reactor 1 is tightly fitted to the reactor heating furnace body 2 , and the reactor heating furnace body 2 heats the stainless steel reactor 1 .

[0058] The gas cabinet 11 is connected to the gas-drum heating furnace body 12 through a pipeline, and the gas flows from the gas cabinet 11 into the gas-drum heating furnace body 12 for preheating.

[0059] The T reactor temperature control thermocouple 3 is directly connected to the TC main controller 4 , and the T reactor temperature control thermocouple 3 transmits the measured temperature signal to the TC main controller 4 .

[0060] The TC main controller 4 is signal-connected with the T1C reactor heating controller 6 and the T2C gas bag heating controller 9. The TC main controller 4 generates control instructions according to the received temperature signals and transmits them to the T1C and T2C controllers.

[0061] The T1C reactor heating controller 6 is connected to the reactor heating power regulator 7 by command, and the T1C controller adjusts the heating power of the reactor heating furnace body 2 according to the received command.

[0062] The above components constitute the main temperature cascade control subsystem and the auxiliary temperature cascade control subsystem, among which the main temperature cascade control subsystem mainly includes the following components:

[0063] T reactor temperature control thermocouple 3: installed inside the stainless steel reactor 1, used to measure the temperature inside the reactor in real time.

[0064] TC main controller 4: A PLC controller with logic judgment function, responsible for receiving the temperature signal transmitted by the T reactor temperature control thermocouple 3, and comparing it with the preset process temperature, and generating control instructions according to the comparison result.

[0065] T1 Reactor Heating Furnace Thermocouple 5: Installed on the reactor heating furnace 2, used to measure the temperature of the furnace to monitor the heating effect.

[0066] T1C reactor heating controller 6: receives the temperature signal of T1 reactor heating furnace thermocouple 5 and the instruction of TC main controller 4, and generates specific heating power adjustment instruction according to these signals.

[0067] Reactor heating power regulator 7: adjusts the heating power output of the reactor heating furnace body 2 according to the instructions of the T1C reactor heating controller 6.

[0068] The connection relationship is as follows:

[0069] The T reactor temperature control thermocouple 3 is directly connected to the TC main controller 4 to transmit real-time temperature signals.

[0070] The TC main controller 4 is connected to the T1 reactor heating furnace body thermocouple 5 and the T1C reactor heating controller 6 respectively, receives the furnace body temperature signal and sends control instructions.

[0071] The T1C reactor heating controller 6 is connected to the reactor heating power regulator 7 to transmit specific heating power adjustment instructions.

[0072] The main temperature cascade control subsystem forms a closed-loop control system. The temperature measured by the T reactor temperature control thermocouple 3 is compared with the preset process temperature. If there is a deviation, the TC main controller 4 will adjust the control instructions and adjust the heating power of the heating furnace through the T1C reactor heating controller 6 and the reactor heating power regulator 7, thereby achieving precise control of the reactor temperature.

[0073] The auxiliary temperature cascade control subsystem mainly includes the following components:

[0074] T reactor temperature control thermocouple 3: also installed inside the stainless steel reactor 1, used to measure the temperature inside the reactor in real time.

[0075] TC main controller 4: shared with the main temperature cascade control subsystem, receives the temperature signal transmitted by the T reactor temperature control thermocouple 3, and generates corresponding control instructions.

[0076] T2 gas-drum heater thermocouple 8: installed on the gas-drum heating furnace body 12, used to measure the temperature of the gas-drum heating furnace body 12.

[0077] T2C gas bag heating controller 9: receives the temperature signal of the T2 gas bag heater thermocouple 8 and the instruction of the TC main controller 4, and generates a heating power adjustment instruction for the gas bag heating furnace body 12.

[0078] Gas bag heating power regulator 10: adjusts the heating power output of the gas bag heating furnace body 12 according to the instructions of the T2C gas bag heating controller 9.

[0079] The connection relationship is as follows:

[0080] The T reactor temperature control thermocouple 3 is also directly connected to the TC main controller 4 to transmit real-time temperature signals.

[0081] The TC main controller 4 is connected to the T2 gas bag heater thermocouple 8 and the T2C gas bag heating controller 9 respectively, receives the temperature signal of the gas bag heating furnace body 12 and sends control instructions.

[0082] The T2C air bag heating controller 9 is connected to the air bag heating power regulator 10 to transmit specific heating power adjustment instructions.

[0083] The auxiliary temperature cascade control subsystem also forms a closed-loop control system. It preheats the gas entering the reactor by adjusting the heating power of the gas-drum heating furnace body 12, thereby indirectly affecting the temperature inside the reactor. When the temperature inside the reactor fluctuates, the TC main controller 4 will adjust the heating power of the gas-drum heating furnace body 12 according to the measurement results of the T reactor temperature control thermocouple 3 to quickly respond and stabilize the reactor temperature. This auxiliary temperature cascade control subsystem can be regarded as a supplement and detailed adjustment to the main temperature cascade control subsystem, which together ensures the precise control of the reactor temperature.

[0084] The present invention also provides a method for temperature control of a carbon nanotube fluidized bed temperature cascade control system, which aims to improve the production efficiency and product quality of carbon nanotubes through precise temperature control. The method mainly includes system startup, the control process of the main temperature cascade control subsystem, and the control process of the auxiliary temperature cascade control subsystem. The following is a detailed description of the steps:

[0085] S1, system startup, preset the temperature setting value SV1 of the main temperature cascade control system and the temperature setting value SV2 of the auxiliary temperature cascade control system:

[0086] During the system startup phase, two important temperature setting values ​​need to be preset: the temperature setting value SV1 of the main temperature cascade control system and the temperature setting value SV2 of the auxiliary temperature cascade control system. These two setting values ​​are determined according to the production process requirements to ensure that the system can operate under stable and appropriate temperature conditions.

[0087] Control process of main temperature cascade control subsystem (S2)

[0088] S21, T reactor temperature control thermocouple 3 measures the temperature inside the stainless steel reactor 1 in real time, and transmits the temperature signal to TC main controller 4:

[0089] The T reactor temperature control thermocouple 3 is used as a key temperature sensor to monitor the temperature inside the stainless steel reactor 1 in real time and accurately transmit the temperature signal to the TC main controller 4.

[0090] S22, the TC main controller 4 compares the received temperature signal with the preset process temperature to determine whether the current temperature deviates from the set value:

[0091] After receiving the temperature signal, the TC main controller 4 immediately compares and analyzes it with the preset process temperature to determine whether the current temperature in the reactor deviates from the preset SV1 value.

[0092] S23, if the temperature deviates from the set value, the TC main controller 4 generates a corresponding control instruction to adjust the set value SV1 of the main temperature cascade control subsystem:

[0093] Once the temperature deviation is found, the TC main controller 4 will quickly generate corresponding control instructions and dynamically adjust the set value SV1 of the main temperature cascade control subsystem to correct the temperature deviation.

[0094] S24, T1 reactor heating furnace body thermocouple 5 measures the furnace body temperature and transmits the signal to T1C reactor heating controller 6:

[0095] The T1 reactor heating furnace body thermocouple 5 monitors the temperature of the heating furnace body to ensure that the furnace body temperature remains within an appropriate range, and transmits the temperature signal to the T1C reactor heating controller 6.

[0096] S25, the T1C controller receives the instruction of the TC main controller 4 and the signal of the T1 thermocouple, generates a control instruction, and adjusts the heating power of the furnace body through the reactor heating power regulator 7 to adjust the reactor temperature:

[0097] The T1C reactor heating controller 6 integrates the received instructions and signals to generate specific control instructions, and adjusts the heating power of the heating furnace through the reactor heating power regulator 7, thereby achieving accurate adjustment of the reactor temperature.

[0098] Control process of auxiliary temperature cascade control subsystem (S3)

[0099] S31, T reactor temperature control thermocouple 3 measures the temperature inside the stainless steel reactor 1 in real time, and transmits the temperature signal to TC main controller 4:

[0100] Similar to the main temperature cascade control subsystem, the T reactor temperature control thermocouple 3 continues to monitor the internal temperature of the reactor in real time and transmits the signal to the TC main controller 4.

[0101] S32, the TC main controller 4 compares the received temperature signal with the preset process temperature to determine whether the current temperature deviates from the set value:

[0102] The TC main controller 4 compares and analyzes the temperature signal again to determine whether the current temperature deviates from the preset SV2 value.

[0103] S33, if the temperature deviates from the set value, the TC main controller 4 generates a corresponding control instruction to adjust the set value SV2 of the auxiliary temperature cascade control subsystem:

[0104] If it is found that the temperature deviates from the SV2 value, the TC main controller 4 will generate a control instruction to adjust the set value SV2 of the auxiliary temperature cascade control subsystem.

[0105] S34, T2 air bag heater thermocouple 8 measures the temperature of the air bag heating furnace body 12, and transmits the signal to T2C air bag heating controller 9:

[0106] The T2 gas bag heater thermocouple 8 monitors the temperature of the gas bag heating furnace body 12 to ensure that the gas preheating process is carried out stably, and transmits the temperature signal to the T2C gas bag heating controller 9.

[0107] S35, the T2C controller receives the instruction of the TC main controller 4 and the signal of the T2 thermocouple, generates a control instruction, and adjusts the heating power of the gas-drum heating furnace body 12 through the gas-drum heating power regulator 10 to preheat the gas, thereby affecting the reactor temperature:

[0108] The T2C gas bag heating controller 9 generates control instructions according to the received instructions and signals, and adjusts the heating power through the gas bag heating power regulator 10 to achieve accurate preheating of the gas, thereby indirectly affecting the reactor temperature and achieving the purpose of stable control.

[0109] Through the above steps, the temperature cascade control system can achieve accurate and stable control of the temperature of the carbon nanotube fluidized bed, ensuring the smooth progress of the production process and the improvement of product quality.

[0110] The present invention also provides a feedforward control step S4:

[0111] S41: Data collection and processing;

[0112] In step S41, the TC main controller 4 (PLC controller with logic judgment function) continuously collects data from multiple sources, including:

[0113] T reactor temperature control thermocouple 3: real-time measurement of the temperature inside the stainless steel reactor 1, which is the core temperature indicator in the reaction process.

[0114] T1 Reactor Heating Furnace Body Thermocouple 5: measures the temperature of the reactor heating furnace body 2 wrapped outside the stainless steel reactor 1, reflecting the heating state of the heating furnace body.

[0115] T2 gas drum heater thermocouple 8: measures the temperature of the gas drum heating furnace body 12, which is crucial for preheating the reaction gas.

[0116] Grid voltage: Monitor the voltage provided by the grid, as voltage fluctuations will directly affect the power output of the heating equipment.

[0117] Gas flow rate: Monitor the gas flow rate entering the reactor, as changes in flow rate will affect the heat balance within the reactor.

[0118] The main controller processes and analyzes the collected data in real time, using algorithms (such as time series analysis, trend prediction, etc.) to identify the changing trends of parameters such as temperature, grid voltage, gas flow, etc. Through these analyses, the main controller can predict possible fluctuations in grid voltage or potential changes in gas flow, which are considered as disturbance factors that may affect the reaction temperature.

[0119] S42: predict disturbance and generate control instructions;

[0120] In step S42, the TC main controller 4 predicts the type and extent of the upcoming disturbance based on the data analysis results in step S41. For example, if the grid voltage has a downward trend, or the gas flow begins to decrease, the main controller will identify these potential disturbances and evaluate their possible impact on the reactor temperature.

[0121] The main controller then generates corresponding control instructions based on the predicted disturbance type and magnitude. These instructions are designed to adjust the setpoints of the primary temperature cascade control system (SV1) and the secondary temperature cascade control system (SV2) in advance to offset the impact of the upcoming disturbance on the reactor temperature. For example, if the grid voltage is predicted to drop, the main controller may increase the values ​​of SV1 and SV2 to compensate for the possible loss of heating power.

[0122] S43: Transmitting control instructions and adjusting heating power;

[0123] In step S43, the TC main controller 4 transmits the generated control instruction to the T1C reactor heating controller 6 and the T2C gas bag heating controller 9. These two controllers are responsible for adjusting the heating power of the reactor heating furnace body 2 and the gas bag heating furnace body 12 respectively.

[0124] T1C reactor heating controller 6: after receiving the instruction from TC main controller 4, adjusts the parameters of reactor heating power regulator 7, thereby changing the heating power of reactor heating furnace body 2, so as to maintain or adjust the temperature inside stainless steel reactor 1.

[0125] T2C gas bag heating controller 9: also receives instructions from TC main controller 4, adjusts the parameters of gas bag heating power regulator 10, changes the heating power of gas bag heating furnace body 12, so as to preheat the gas entering the reactor, thereby affecting the reactor temperature.

[0126] Embodiment 1, this embodiment describes the detailed process of the feedforward control step S4. In this embodiment, the following specific parameter values ​​are set:

[0127] The temperature setting value of the main temperature cascade control system (SV1): 800℃; the temperature setting value of the auxiliary temperature cascade control system (SV2): 750℃; the normal value of the grid voltage: 220V; the normal value of the gas flow: 50L / min;

[0128] S41: Data collection and processing; TC main controller 4 continuously collects the following data:

[0129] T reactor temperature control thermocouple 3: the current measured temperature is 795°C; T1 reactor heating furnace thermocouple 5: the current measured temperature is 820°C; T2 gas bag heater thermocouple 8: the current measured temperature is 745°C; grid voltage: the current voltage is 222V (slightly fluctuating); gas flow: the current flow is 48L / min (slightly decreasing);

[0130] The main controller processes and analyzes this data and identifies the following change trends:

[0131] Temperature: The temperature inside the reactor is close to the set value, but slightly lower; the furnace temperature and the temperature of the gas-drum heating furnace 12 are slightly higher than the set value.

[0132] Grid voltage: increased from the normal value of 220V to 222V, with an upward trend.

[0133] Gas flow rate: dropped from the normal value of 50L / min to 48L / min, with a downward trend.

[0134] Based on these trends, Master Controller predicts:

[0135] An increase in grid voltage may lead to an increase in heating power and thus an increase in reactor temperature.

[0136] A decrease in gas flow rate may result in a decrease in the temperature inside the reactor, because less gas flow means less heat is removed.

[0137] S42: Adjust in advance: The TC main controller 4 decides to adjust SV1 and SV2 in advance to cope with the upcoming disturbance based on the prediction results.

[0138] Adjust SV1 (primary temperature cascade control system set value): from 800℃ to 798℃ to prevent overheating caused by rising grid voltage. Adjust SV2 (secondary temperature cascade control system set value): from 750℃ to 752℃ to compensate for the temperature drop caused by the decrease in gas flow.

[0139] S43: control command transmission and heating power adjustment;

[0140] The TC main controller 4 transmits the adjusted SV1 and SV2 values ​​to the corresponding controllers:

[0141] SV1 = 798°C is transmitted to the T1C reactor heating controller 6.

[0142] Transmit SV2=752℃ to T2C gas bag heating controller 9.

[0143] The T1C reactor heating controller 6 and the T2C gas bag heating controller 9 adjust their respective heating power parameters according to the received instructions:

[0144] The T1C controller slightly reduces the heating power of the reactor heating furnace 2 through the reactor heating power regulator 7 to prevent overheating. The T2C controller appropriately increases the heating power of the gas drum heating furnace 12 through the gas drum heating power regulator 10 to preheat more gas, thereby compensating for the effect of the gas flow rate reduction.

[0145] Through such a feedforward control step, the system can predict and respond to potential disturbances in advance, ensuring stable control of the temperature of the carbon nanotube fluidized bed.

[0146] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A carbon nanotube fluidized bed temperature cascade control system, comprising: The stainless steel reactor is the main equipment for chemical reactions; A reactor heating furnace wrapped around the outside of the stainless steel reactor to heat the stainless steel reactor; a gas cabinet for storing and supplying the gas required for the reaction; a gas bag heating furnace for preheating the gas; characterized in that it is also provided with: The T reactor temperature control thermocouple is installed inside the stainless steel reactor to measure the temperature inside the stainless steel reactor in real time; The TC main controller is a PLC controller with logic judgment function, which receives the temperature signal measured by the temperature control thermocouple of the T reactor and controls the operation of the system; T1 reactor heating furnace thermocouple, installed on the reactor heating furnace to measure the furnace temperature; The T1C reactor heating controller receives the temperature signal of the thermocouple of the T1 reactor heating furnace and the signal of the TC main controller, and generates control instructions; The reactor heating power regulator is connected to the T1C reactor heating controller and adjusts the heating power output of the reactor heating furnace according to the instructions of the T1C reactor heating controller; T2 gas bag heater thermocouple, installed on the gas bag heating furnace body, measures the temperature of the gas bag heating furnace body; T2C gas bag heating controller receives the temperature signal of the thermocouple of T2 gas bag heater and the signal of TC main controller, and generates control instructions; The gas bag heating power regulator is connected to the T2C gas bag heating controller and adjusts the heating power output of the gas bag heating furnace body according to the instructions of the T2C gas bag heating controller.

2. A carbon nanotube fluidized bed temperature cascade control system according to claim 1, characterized in that: The system is equipped with a main temperature cascade control subsystem and a sub-temperature cascade control subsystem, where: The main temperature cascade control subsystem includes a T reactor temperature control thermocouple, a TC main controller, a T1 reactor heating furnace body thermocouple, a T1C reactor heating controller, and a reactor heating power regulator; wherein: the T reactor temperature control thermocouple is connected to the TC main controller, the TC main controller is respectively connected to the T1 reactor heating furnace body thermocouple and the T1C reactor heating controller, and the T1C reactor heating controller is further connected to the reactor heating power regulator, forming the first closed-loop cascade control subsystem; The auxiliary temperature cascade control subsystem includes a T reactor temperature control thermocouple, a TC main controller, a T2 gas bag heater thermocouple, a T2C gas bag heating controller, and a gas bag heating power regulator; wherein: the T reactor temperature control thermocouple is connected to the TC main controller, the TC main controller is respectively connected to the T2 gas bag heater thermocouple and the T2C gas bag heating controller, and the T2C gas bag heating controller is further connected to the gas bag heating power regulator to form a second closed-loop cascade control system.

3. A method for temperature control using a carbon nanotube fluidized bed temperature cascade control system as claimed in claim 2, characterized in that: Proceed as follows: S1, system startup, preset the temperature setting value SV1 of the main temperature cascade control system and the temperature setting value SV2 of the auxiliary temperature cascade control system; The control process S2 of the main temperature cascade control subsystem and the control process S3 of the auxiliary temperature cascade control subsystem are carried out synchronously, and the specific process includes: S21, T reactor temperature control thermocouple measures the temperature inside the stainless steel reactor in real time and transmits the temperature signal to the TC main controller; S22, the TC main controller compares the received temperature signal with the preset process temperature to determine whether the current temperature deviates from the set value; S23, if the temperature deviates from the set value, the TC main controller generates a corresponding control instruction to adjust the set value SV1 of the main temperature cascade control subsystem; S24, T1 reactor heating furnace body thermocouple measures furnace body temperature and transmits the signal to T1C reactor heating controller; S25, the T1C controller receives the instruction of the TC main controller and the signal of the T1 thermocouple, generates a control instruction, and adjusts the heating power of the furnace body through the reactor heating power regulator to adjust the reactor temperature; S31, T reactor temperature control thermocouple measures the temperature inside the stainless steel reactor in real time and transmits the temperature signal to the TC main controller; S32, the TC main controller compares the received temperature signal with the preset process temperature to determine whether the current temperature deviates from the set value; S33, if the temperature deviates from the set value, the TC main controller generates a corresponding control instruction to adjust the set value SV2 of the auxiliary temperature cascade control subsystem; S34, T2 gas bag heater thermocouple measures the temperature of the gas bag heating furnace body and transmits the signal to T2C gas bag heating controller; S35, T2C controller receives the instruction of TC main controller and the signal of T2 thermocouple, generates control instruction, and adjusts the heating power of gas-drum heating furnace through gas-drum heating power regulator to preheat gas, thereby affecting reactor temperature.

4. The method according to claim 3, characterized in that: The step S4 of feedforward control is also included, which is as follows: S41, TC main controller continuously collects temperature data, grid voltage, and gas flow data from T reactor temperature control thermocouple, T1 reactor heating furnace thermocouple, and T2 gas bag heater thermocouple. The main controller processes and analyzes the collected data to identify the changing trends of temperature, grid voltage, and gas flow parameters, and predicts potential disturbances caused by fluctuations in grid voltage or changes in gas flow. S42, TC main controller generates control instructions based on the predicted disturbance type and degree, and adjusts SV1 and SV2 in advance to deal with the impending disturbance; S43, the TC main controller transmits the generated control instruction to the T1C reactor heating controller and the T2C gas bag heating controller, and the T1C reactor heating controller and the T2C gas bag heating controller adjust their respective heating power parameters according to the instruction.

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