Carbon nanotube fluidized bed temperature cascade control system and method

Abstract

The present application relates to carbon nanotube preparation technical field, provide a kind of carbon nanotube fluidized bed temperature cascade control system and method, system includes by stainless steel reactor, reactor heating furnace body, gas cabinet and gas package heating furnace body etc. Main, vice temperature cascade control subsystem is formed. Main temperature cascade control subsystem is formed by T reactor temperature control thermocouple, TC main controller and other components closed loop control, ensure that reactor basic temperature is stable;Vice temperature cascade control subsystem is controlled to gas package heating furnace body by similar components, to preheat gas influences reactor temperature. System also introduces feedforward control, TC main controller collects temperature, voltage, flow and other data, predicts disturbance and adjusts set value in advance, adjusts heating power by reactor heating power regulator and gas package heating power regulator, realizes the accurate control to reactor temperature. The present application effectively improves the response speed and precision of temperature control, guarantees the quality and stability of carbon nanotube production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of carbon nanotube preparation, and in particular to a carbon nanotube fluidized bed temperature cascade control system and method. BACKGROUND

[0002] A fluidized bed is a commonly used reactor for gas-phase reactions. When the reaction gas passes through the reactor, the catalytic particles are suspended by the gas flow and tumble and flow vigorously within the reactor, exhibiting high dynamic mixing. The contact area between the particles and the gas is greatly increased, greatly increasing the mass transfer (oxidation, reactants, products, etc.) and heat exchange between the gas and the solid, which is beneficial for rapid and efficient chemical reactions or physical processes (drying, cooling, adsorption, etc.). It is an essential device for mass production of multi-walled carbon nanotubes.

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

[0004] The fluidized bed reactor has large inertia and large lag characteristics, making it difficult for conventional PID controllers 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, affecting the accuracy and stability of temperature control. In actual production processes, this manifests itself when the temperature inside the reactor fluctuates due to process disturbances, the system cannot immediately adjust, the temperature recovery speed is slow, and even temperature overshoot or undershoot may occur. This not only directly reduces production efficiency, but also may cause damage to the equipment due to long-term temperature fluctuations, increasing maintenance costs. More seriously, this poor control effect and system response lag can seriously affect the quality and consistency of the product, adversely affecting the production and application of carbon nanotubes. In addition, the existing system mainly relies on feedback control, lacking a feedforward control mechanism to predict and compensate for potential disturbances, further limiting the system's ability to respond quickly to temperature changes. SUMMARY

[0005] In order to solve the problems in the background art, the present application provides a carbon nanotube fluidized bed temperature cascade control system, which comprises: a stainless steel reactor as a main chemical reaction device; a reactor heating furnace body wrapped outside the stainless steel reactor for heating the stainless steel reactor; a gas cabinet for storing and supplying the required gas for the reaction; a gas bag heating furnace body for preheating the gas; and further comprising:

[0006] A 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] A TC main controller is a PLC controller with a logic judgment function, which receives the temperature signal measured by the T reactor temperature control thermocouple and controls the system operation;

[0008] A T1 reactor heating furnace body thermocouple is installed on the reactor heating furnace body to measure the furnace body temperature;

[0009] A T1C reactor heating controller receives the temperature signal of the T1 reactor heating furnace body thermocouple and the signal of the TC main controller, and generates a control instruction;

[0010] A reactor heating power regulator is connected to the T1C reactor heating controller, which adjusts the heating power output of the reactor heating furnace body according to the instruction of the T1C reactor heating controller;

[0011] A T2 gas bag heater thermocouple is installed on the gas bag heating furnace body to measure the temperature of the gas bag heating furnace body;

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

[0013] A gas bag heating power regulator is connected to the T2C gas bag heating controller, which adjusts the heating power output of the gas bag heating furnace body according to the instruction of the T2C gas bag heating controller.

[0014] The system is provided with a main temperature cascade control subsystem and a secondary temperature cascade control subsystem, wherein:

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

[0016] The secondary temperature cascade control subsystem comprises a T reactor temperature control thermocouple, a TC main controller, a T2 gas pocket heater thermocouple, a T2C gas pocket heating controller, and a gas pocket heating power regulator.

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

[0018] S1, system startup, presetting a temperature set value SV1 of a primary temperature cascade control system and a temperature set value SV2 of a secondary temperature cascade control system;

[0019] The control process S2 of the primary temperature cascade control subsystem and the control process S3 of the secondary temperature cascade control subsystem are performed synchronously, and the specific process comprises:

[0020] S21, the 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 primary temperature cascade control subsystem.

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

[0024] 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.

[0025] S31, the 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 secondary temperature cascade control subsystem.

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

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

[0030] Further, the step S4 of feedforward control is further included, and the step S4 is specifically as follows:

[0031] S41, the TC main controller continuously collects the temperature data of the T reactor temperature control thermocouple, the T1 reactor heating furnace body thermocouple and the T2 gas blanket heater thermocouple, the grid voltage and the gas flow data, the main controller processes and analyzes the collected data to identify the change trend of the temperature, the grid voltage and the gas flow parameters, and predict the potential disturbance of the grid voltage fluctuation or the gas flow change;

[0032] S42, the TC main controller generates a control instruction according to the predicted disturbance type and degree, and adjusts SV1 and SV2 in advance to cope 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 blanket heating controller, and the T1C reactor heating controller and the T2C gas blanket heating controller adjust the heating power parameters of each other according to the instruction.

[0034] The present application has the following beneficial effects:

[0035] The present application innovatively designs a temperature cascade control system, which includes a main temperature cascade control subsystem and a vice temperature cascade control subsystem, and designs a corresponding control strategy, which significantly improves the response speed and adjustment accuracy of the system. The system realizes fine adjustment of the heating power through the cooperative work of the stainless steel reactor, the reactor heating furnace body, the gas cabinet, the gas blanket heating furnace body and multiple temperature controllers and power regulators, and ensures the constancy and stability of the internal temperature of the reactor.

[0036] The temperature cascade control system of the application adopts an advanced double-closed-loop cascade control strategy, that is, combining a main temperature cascade control subsystem and a secondary 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 secondary temperature cascade control subsystem further refines the adjustment to cope with more subtle temperature fluctuations. Both complement each other and together 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, further improving the stability and reliability of the system.

[0037] At the same time, the application installs a T reactor temperature control thermocouple inside the stainless steel reactor, changing the traditional method of setting temperature measuring points only on the outer wall of the reactor, 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 accurate control instructions, so that the reactor can continuously operate under optimal temperature conditions, providing a strong guarantee for the stability and reliability of the preparation process. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is the structure diagram of the carbon nanotube fluidized bed temperature cascade control system of the application.

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

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

[0041] Figure 4 is the existing fluidized bed single-loop temperature control principle diagram.

[0042] Markings 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 pocket heater thermocouple; 9, T2C gas pocket heating controller; 10, gas pocket heating power regulator; 11, gas cabinet; 12, gas pocket heating furnace body. DETAILED DESCRIPTION

[0044] The technical solutions in the present application will be described clearly and completely below with reference to the drawings in the present application. In addition, the forms of the structures described in the following embodiments are only examples, and the present application is not limited to the structures described in the following embodiments. All other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0045] With reference to Figures 1-4 The present application provides a carbon nanotube fluidized bed temperature cascade control system, which comprises the following components:

[0046] Stainless steel reactor 1: as the main equipment for chemical reaction. The core part of the system, 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 combined with the stainless steel reactor 1, providing the temperature environment required for reaction by heating.

[0048] Gas cabinet 11: stores and supplies the gas required for reaction. Connected with the gas pack heating furnace body 12 through pipeline, ensuring that the gas can smoothly enter the heating and reaction process.

[0049] Gas pack heating furnace body 12: preheats the gas to improve the reaction efficiency. Connected with the gas cabinet 11, receives the gas and preheats it; at the same time, connected with the gas pack heating controller and the heating power regulator, receives the control instruction to adjust the heating power.

[0050] T reactor temperature control thermocouple 3: installed inside the stainless steel reactor 1, measuring the temperature inside the reactor in real time. Connected with the TC main controller 4, transmitting the temperature signal.

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

[0052] T2 gas pack heater thermocouple 8: installed on the gas pack heating furnace body 12, measuring the temperature of the gas pack heating furnace body 12. Connected with the T2C gas pack heating controller 9, transmitting the temperature signal.

[0053] TC main controller 4: a PLC controller with logic judgment function. Receiving the temperature signal of the T reactor temperature control thermocouple 3, and connected with the T1C reactor heating controller 6 and the T2C gas pack heating controller 9, transmitting the control instruction.

[0054] T1C reactor heating controller 6: receiving the temperature signal of the T1 reactor heating furnace body thermocouple 5 and the signal of the TC main controller 4, generating the control instruction. Connected with the reactor heating power regulator 7, transmitting the control instruction.

[0055] T2C gas pocket heating controller 9: receives temperature signals from T2 gas pocket heater thermocouple 8 and signals from TC main controller 4, and generates control instructions. The control instructions are transmitted to gas pocket heating power regulator 10.

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

[0057] Stainless steel reactor 1 is tightly attached to reactor heating furnace body 2, and reactor heating furnace body 2 heats stainless steel reactor 1.

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

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

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

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

[0062] The above components constitute a main temperature cascade control subsystem and a secondary temperature cascade control subsystem, wherein the main temperature cascade control subsystem mainly includes the following components:

[0063] T reactor temperature control thermocouple 3: installed inside 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 temperature signals transmitted by T reactor temperature control thermocouple 3, and comparing them with preset process temperatures, and generating control instructions according to the comparison results.

[0065] T1 reactor heating furnace body thermocouple 5: installed on reactor heating furnace body 2, used to measure the temperature of the furnace body to monitor the heating effect.

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

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

[0068] The connection relationship is as follows:

[0069] T reactor temperature control thermocouple 3 is directly connected to TC main controller 4, and transmits real-time temperature signals.

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

[0071] T1C reactor heating controller 6 is connected to reactor heating power regulator 7, and transmits specific heating power adjustment instructions.

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

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

[0074] T reactor temperature control thermocouple 3: also installed inside 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 temperature signals transmitted by T reactor temperature control thermocouple 3, and generates corresponding control instructions.

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

[0077] T2C gas pocket heating controller 9: receives temperature signals from T2 gas pocket heater thermocouple 8 and instructions from TC main controller 4, and generates heating power adjustment instructions for gas pocket heating furnace body 12.

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

[0079] The connection relationship is as follows:

[0080] T reactor temperature control thermocouple 3 is also directly connected to TC main controller 4, and transmits real-time temperature signals.

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

[0082] T2C gas pocket heating controller 9 is connected with gas pocket heating power regulator 10, and transmits specific heating power adjustment instructions.

[0083] The secondary temperature cascade control subsystem also forms a closed-loop control system. It indirectly affects the temperature in the reactor by adjusting the heating power of the gas pocket heating furnace body 12 to preheat the gas entering the reactor. When the internal temperature of the reactor fluctuates, the TC main controller 4 will adjust the heating power of the gas pocket 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 secondary temperature cascade control subsystem can be seen as a supplement and refinement of the main temperature cascade control subsystem, working together to ensure accurate control of the reactor temperature.

[0084] The present application also provides a method for temperature control of a carbon nanotube fluidized bed temperature cascade control system, aiming to improve the production efficiency and product quality of carbon nanotubes through precise temperature control. The method mainly includes system startup, control process of the main temperature cascade control subsystem and control process of the secondary temperature cascade control subsystem. The following is a detailed step introduction:

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

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

[0087] Control process of the 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 the TC main controller 4:

[0089] T reactor temperature control thermocouple 3 as a key temperature sensor, real-time monitoring the temperature inside the stainless steel reactor 1, and accurately transmits the temperature signal to the TC main controller 4.

[0090] S22, 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] TC main controller 4 receives the temperature signal, immediately compares and analyzes the preset process temperature, and determines 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 quickly generates a corresponding control instruction to 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] T1 reactor heating furnace body thermocouple 5 monitors the temperature of the heating furnace body to ensure that the furnace body temperature is maintained within the appropriate range, and transmits the temperature signal to T1C reactor heating controller 6.

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

[0097] T1C reactor heating controller 6 receives the instructions and signals, generates specific control instructions, and adjusts the heating power of the heating furnace body through reactor heating power regulator 7, thereby realizing accurate adjustment of the reactor temperature.

[0098] Control process of the secondary 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 the TC main controller 4:

[0100] The same as the main temperature cascade control subsystem, T reactor temperature control thermocouple 3 continues to monitor the temperature inside the reactor in real time and transmits the signal to the TC main controller 4.

[0101] S32, 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] TC main controller 4 again compares and analyzes the temperature signal 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 secondary temperature cascade control subsystem:

[0104] If the temperature deviates from the SV2 value, the TC master controller 4 will generate a control instruction to adjust the set value SV2 of the secondary temperature cascade control subsystem.

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

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

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

[0108] The T2C gas blanket heating controller 9 generates a control instruction according to the received instruction and signal, adjusts the heating power through the gas blanket heating power regulator 10, realizes accurate preheating of the gas, and indirectly affects the reactor temperature, so as to achieve the purpose of stable control.

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

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

[0111] S41: data collection and processing;

[0112] In the S41 step, the TC master controller 4 (a 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 index 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 blanket heater thermocouple 8: measures the temperature of the gas blanket heating furnace body 12, which is crucial for preheating the reaction gas.

[0116] Power grid voltage: monitors the voltage provided by the power grid, because voltage fluctuations will directly affect the power output of the heating equipment.

[0117] Gas flow: monitors the gas flow into the reactor, because changes in flow will affect the heat balance in the reactor.

[0118] The main controller processes and analyzes these 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 potential fluctuations in grid voltage or changes in gas flow, which are considered as disturbance factors that may affect the reactor temperature.

[0119] S42: Predicting disturbances and generating control instructions;

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

[0121] Subsequently, the main controller will generate corresponding control instructions according to the predicted type and degree of disturbance. These instructions aim to adjust the set values of the main 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 it is predicted that the grid voltage will decrease, 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 instructions to the T1C reactor heating controller 6 and the T2C gas pocket heating controller 9. These two controllers are responsible for adjusting the heating power of the reactor heating furnace body 2 and the gas pocket heating furnace body 12, respectively.

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

[0125] T2C gas pocket heating controller 9: Similarly, it receives instructions from the TC main controller 4 and adjusts the parameters of the gas pocket heating power regulator 10 to change the heating power of the gas pocket heating furnace body 12, thereby preheating the gas entering the reactor and affecting the reactor temperature.

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

[0127] Main temperature cascade control system temperature set value (SV1): 800℃; Secondary temperature cascade control system temperature set value (SV2): 750℃; Grid voltage normal value: 220V; Gas flow normal value: 50L / min;

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

[0129] T reactor control temperature thermocouple 3: current measured temperature is 795℃; T1 reactor furnace body thermocouple 5: current measured temperature is 820℃; T2 gas pocket heater thermocouple 8: current measured temperature is 745℃; Grid voltage: current voltage is 222V (slightly fluctuating); Gas flow: current flow is 48L / min (slightly decreasing);

[0130] The main controller processes and analyzes these data, and identifies the following trends:

[0131] Temperature: The internal temperature of the reactor is close to the set value, but slightly lower; The furnace body temperature and the gas pocket heater body 12 temperature are slightly higher than the set value.

[0132] Grid voltage: From the normal value 220V to 222V, there is an upward trend.

[0133] Gas flow: From the normal value 50L / min to 48L / min, there is a downward trend.

[0134] Based on these trends, the main controller predicts:

[0135] The rise of grid voltage may lead to an increase in heating power, which in turn may cause the reactor temperature to rise.

[0136] The decrease in gas flow may lead to a decrease in internal reactor temperature, as reduced gas flow means less heat is carried away.

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

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

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

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

[0141] SV1 = 798℃ is transmitted to T1C reactor heating controller 6.

[0142] SV2 = 752℃ is transmitted to T2C gas pocket heating controller 9.

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

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

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

[0146] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A carbon nanotube fluidized bed temperature cascade control method, comprising a stainless steel reactor as a main chemical reaction device; a reactor heating furnace body wrapped outside the stainless steel reactor for heating the stainless steel reactor; a gas cabinet for storing and supplying reaction required gas; a gas pack heating furnace body for preheating the gas; characterized in that, a main temperature cascade control subsystem and a secondary temperature cascade control subsystem are arranged in the system, wherein: the main temperature cascade control subsystem comprises 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 with the TC main controller, the TC main controller is connected with the T1 reactor heating furnace body thermocouple and the T1C reactor heating controller respectively, the T1C reactor heating controller is connected with the reactor heating power regulator again, forming a first closed loop cascade control subsystem; the secondary temperature cascade control subsystem comprises a T reactor temperature control thermocouple, a TC main controller, a T2 gas pack heater thermocouple, a T2C gas pack heating controller, and a gas pack heating power regulator; wherein: the T reactor temperature control thermocouple is connected with the TC main controller, the TC main controller is connected with the T2 gas pack heater thermocouple and the T2C gas pack heating controller respectively, the T2C gas pack heating controller is connected with the gas pack heating power regulator again, forming a second closed loop cascade control system; the control method is carried out according to the following steps: S1, system starts, presetting a temperature set value SV1 of the main temperature cascade control system and a temperature set value SV2 of the secondary temperature cascade control system; the control process S2 of the main temperature cascade control subsystem is carried out synchronously with the control process S3 of the secondary temperature cascade control subsystem, and the specific process of S2 comprises: S21, the 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, and judges 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, the T1 reactor heating furnace body thermocouple measures the furnace body temperature and transmits the signal to the 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; the specific process of S3 comprises: S31, the 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, and judges 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 secondary temperature cascade control subsystem; S34, the T2 gas pack heater thermocouple measures the gas pack heating furnace body temperature and transmits the signal to the T2C gas pack heating controller; ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ S35, T2C controller receives instructions from TC master controller and signals from T2 thermocouple, generates control instructions, adjusts the heating power of the gas pocket heating furnace body through the gas pocket heating power regulator, preheats the gas, and further affects the temperature of the reactor.

2. The method of claim 1, wherein, Further comprising a feedforward control step S4, as follows: S41, the TC master controller continuously collects temperature data from the T reactor temperature control thermocouple, T1 reactor furnace body thermocouple and T2 gas pocket heater thermocouple, power grid voltage, gas flow data, and the master controller processes and analyzes the collected data to identify the change trend of temperature, power grid voltage and gas flow parameters, and predict potential disturbances of power grid voltage fluctuations or gas flow changes; S42, the TC master controller generates control instructions according to the predicted disturbance type and degree, and adjusts SV1 and SV2 in advance to cope with the impending disturbance; S43, the TC master controller transmits the generated control instructions to the T1C reactor heating controller and the T2C gas pocket heating controller, and the T1C reactor heating controller and the T2C gas pocket heating controller adjust their respective heating power parameters according to the instructions.

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