Carbon nanotube synthesis apparatus, method, and storage medium

Abstract

The embodiment of the present specification provides a carbon nanotube synthesis device, method and storage medium, the device comprising: a physical synthesis component: comprising a pressure container for accommodating mixed raw materials and heating the mixed raw materials, a preheating system for heating carrier gas, a high-temperature reaction furnace for generating carbon nanotubes, and a gas conveying pipeline connecting the pressure container, the preheating system and the high-temperature reaction furnace; a sensing and monitoring array: for collecting device state data; an execution driving unit: for adjusting device operation parameters; and a controller: electrically connected with the sensing and monitoring array and the execution driving unit; the controller is configured to: based on the device state data, evaluate the gasification process and / or the conveying state of the mixed raw materials; in response to the gasification process and / or the conveying state satisfying a preset condition, control the execution driving unit to adjust the device operation parameters, so as to lock the supply amount of components entering the high-temperature reaction furnace and / or guarantee the conveying stability of the mixed raw materials.

Description

Cross-references

[0001] This application claims priority to Chinese application No. PCT / CN2026 / 109676, filed on July 9, 2026. Technical Field

[0002] This specification relates to the field of carbon nanotube preparation, and in particular to a carbon nanotube synthesis apparatus, method and storage medium. Background Technology

[0003] Carbon nanotubes, due to their superior mechanical, electrical, and thermal properties, have broad application prospects in aerospace, microelectronics, and high-performance composite materials. Chemical vapor deposition (CVD) is currently the mainstream technology for preparing continuous carbon nanotube aggregates. Its core process involves vaporizing a mixture of carbon source, catalyst, and other raw materials, which is then carried by a carrier gas and transported through a gas pipeline to a high-temperature reactor for catalytic pyrolysis. Traditional synthesis apparatuses typically use injection pumps to directly inject liquid raw materials into the high-temperature reaction zone. However, different raw materials require different vaporization temperatures, resulting in a sequential entry into the reaction zone. This prevents them from participating in the catalytic pyrolysis reaction simultaneously, severely reducing the growth efficiency of carbon nanotubes and the uniformity of product quality.

[0004] To overcome the aforementioned shortcomings, subsequent technical solutions improved feed synchronization by pre-gasifying the mixed raw materials and mixing them with preheated carrier gas. However, in actual continuous production, the growth of carbon nanotubes is highly sensitive to temperature stability, atmosphere concentration ratio, and fluid dynamics. Currently, most such devices remain in a semi-automatic stage, suffering from problems such as easy mismatch of raw material flow rates, easy condensation and coking in pipelines, and inaccurate determination of gasification state, making it difficult to guarantee product quality consistency. Meanwhile, the gas delivery pipeline for transporting the mixed gas is a critical weak link in ensuring synthesis stability. During transportation, the mixed raw materials are prone to condensation due to the pipe wall temperature being lower than its dew point, causing liquid carbon source to precipitate on the pipe wall and gradually coke, clogging the pipeline and disrupting the precise ratio of raw material components. Conventional single-layer pipe wall structures or simple heating methods cannot form active isolation inside the pipeline. When the carbon source concentration or system pressure fluctuates, the fluid inside the pipe directly contacts the high-temperature metal wall, posing a risk of premature pyrolysis or catalytic carbon deposition. In addition, the safety interlock protection of existing synthesis units under abnormal operating conditions such as combustible gas leakage is relatively lagging, especially in terms of insufficient consideration for micro-leakage and release safety, making it difficult to fully guarantee the safety of personnel and equipment in continuous production.

[0005] Therefore, it is necessary to provide a carbon nanotube synthesis device, method, and storage medium that can achieve multi-parameter linkage control of temperature, pressure, and flow, actively construct an anti-condensation gas film inside the tube, and implement safety interlocks to solve problems such as raw material flow mismatch, inaccurate gasification state determination, pipeline condensation and carbon buildup blockage, and insufficient safety protection under abnormal operating conditions caused by open-loop control in existing synthesis devices. Summary of the Invention

[0006] This specification provides one or more embodiments of a carbon nanotube synthesis apparatus, the apparatus comprising: a physical synthesis component including a pressure vessel for containing and heating a mixed raw material for vaporization, a preheating system for heating a carrier gas, a high-temperature reactor for generating carbon nanotubes, and a gas supply pipeline connecting the pressure vessel, the preheating system, and the high-temperature reactor; the pressure vessel, the preheating system, and the high-temperature reactor are connected via the gas supply pipeline; a sensor monitoring array for acquiring apparatus status data; an execution drive unit for adjusting apparatus operating parameters; and a controller electrically connected to the sensor monitoring array and the execution drive unit; the controller is configured to: evaluate the vaporization process of the mixed raw material and / or the transport status of the mixed raw material in the gas supply pipeline based on the apparatus status data; and, in response to the vaporization process and / or the transport status meeting preset conditions, control the execution drive unit to adjust the apparatus operating parameters to lock the supply amount of the component entering the high-temperature reactor and / or ensure the transport stability of the mixed raw material in the gas supply pipeline.

[0007] This specification provides one or more embodiments of a carbon nanotube synthesis method, the method being executed by a controller in a carbon nanotube synthesis apparatus; the method includes: evaluating the gasification process of a mixed raw material and / or the transport status of the mixed raw material in a gas delivery pipeline based on apparatus status data; in response to the gasification process and / or the transport status meeting preset conditions, controlling an execution drive unit to adjust apparatus operating parameters to lock the supply amount of components entering the high-temperature reactor and / or ensure the transport stability of the mixed raw material in the gas delivery pipeline.

[0008] This specification provides one or more embodiments of a storage medium storing a computer program, which, when executed by a processor, implements a method for synthesizing carbon nanotubes. Attached Figure Description

[0009] This specification will be further described by way of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting; in these embodiments, the same reference numerals denote the same structures, wherein: Figure 1 This is a schematic diagram of the carbon nanotube synthesis apparatus shown in some embodiments of this specification; Figure 2 These are schematic diagrams of the preheating system and high-temperature reactor shown in some embodiments of this specification; Figure 3 These are schematic diagrams of the preheating system and high-temperature reactor shown in other embodiments of this specification; Figure 4 This is a flowchart illustrating the use of a carbon nanotube synthesis apparatus according to some embodiments of this specification; Figure 5 This is a flowchart illustrating a carbon nanotube synthesis method according to some embodiments of this specification; Figure 6 This is a partial structural schematic diagram of a carbon nanotube synthesis apparatus according to some embodiments of this specification; Figure 7 This is an exemplary flowchart illustrating the generation of heat-tracing gas according to some embodiments of this specification; Figure 8 This is a cross-sectional structural diagram of an axially segmented gas pipeline according to other embodiments of this specification; Figure 9 This is a schematic flowchart illustrating the process of determining the target pump inlet pressure according to some embodiments of this specification; Figure 10 These are schematic diagrams of the interlocking protection system shown in some embodiments of this specification; and Figure 11 This is a schematic diagram of the radial cross-section of a gas transmission pipeline according to some embodiments of this specification. Detailed Implementation

[0010] Exemplary embodiments or implementations will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with this specification. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this specification as detailed in the appended claims.

[0011] The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of this specification. The singular forms “a,” “the,” and “the” as used in this specification and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0012] It should be understood that the terms "first," "second," and similar terms used in this specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms "an" or "a" and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. Unless otherwise stated, the terms "front," "rear," "lower," and / or "upper" and similar terms are for illustrative purposes only and are not limited to a location or spatial orientation. The terms "comprising" or "including" and similar terms mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, but do not exclude other elements or objects.

[0013] This specification provides a carbon nanotube synthesis apparatus, method, and storage medium, primarily applicable to industrial applications of continuous batch production of high-quality single-walled carbon nanotube aggregates (such as carbon nanotube powder), carbon nanotube fibers, and films. Based on chemical vapor deposition (CVD), the apparatus deeply integrates intelligent sensing, closed-loop control, and execution units. It also features a gas delivery pipeline with gas film protection, an intelligent gas path control system, segmented heating components, and a comprehensive interlocking protection and carbon removal control mechanism. This aims to solve core problems in traditional equipment that affect long-term continuous and stable production, such as raw material flow mismatch, ambiguous gasification state, pipeline condensation and carbon buildup, and delayed safety interlocks. It is particularly suitable for large-scale carbon nanotube production lines with stringent requirements for product consistency and safe production.

[0014] Figure 1 This is a schematic diagram of a carbon nanotube synthesis apparatus according to some embodiments of this specification.

[0015] In some embodiments, such as Figure 1 As shown, a carbon nanotube synthesis device includes: a physical synthesis component including a pressure vessel 1 for containing and heating a mixed raw material 5, a preheating system 2 for heating a carrier gas 6, and a high-temperature reactor 3 for generating carbon nanotubes 7; and a gas supply pipe 4 connecting the pressure vessel 1, the preheating system 2, and the high-temperature reactor 3, wherein the pressure vessel 1, the preheating system 2, and the high-temperature reactor 3 are connected via the gas supply pipe 4; a sensor monitoring array for collecting device status data; an execution drive unit for adjusting device operating parameters; and a controller electrically connected to the sensor monitoring array and the execution drive unit.

[0016] In some embodiments, such as Figure 1As shown, pressure vessel 1 is connected to high-temperature reactor 3 via gas pipeline 4, and preheating system 2 is connected to gas pipeline 4; pressure vessel 1, preheating system 2 and high-temperature reactor 3 are connected internally; gaseous mixed raw material formed after heating and gasification is output from pressure vessel 1, and after merging with the heated carrier gas output from preheating system 2 in gas pipeline 4, they enter high-temperature reactor 3 together.

[0017] The physical synthesis components are the basic hardware for realizing carbon nanotube growth, including pressure vessel 1, preheating system 2 and high-temperature reactor 3.

[0018] Pressure vessel 1 is a sealed container capable of withstanding high pressure and can be made of materials such as stainless steel. Pressure vessel 1 is used to contain mixed raw materials, withstand the internal pressure during the gasification process, and provide a detection environment for the first temperature sensor and the first pressure sensor.

[0019] In some embodiments, a pressure gauge is installed on the top of the pressure vessel to monitor its operation. Excessive pressure indicates a danger, while insufficient pressure indicates the exhaustion of the mixed raw materials. The heating temperature for heating and pressurizing the pressure vessel 1 is 200°C–300°C, and the pressurization pressure is 0.001 MPa–10 MPa. In application, this temperature allows the mixed raw materials to vaporize without causing decomposition of the reactants, thus improving the stability of the reactant vaporization process.

[0020] The mixed feedstock refers to the mixture packed inside the pressure vessel 1, which contains at least a gasifiable carbon source, a catalyst, and reaction aids. The mixed feedstock is heated and pressurized in the pressure vessel 1, then vaporized and mixed together to form a gaseous mixed feedstock.

[0021] The carbon source includes any one or any combination of methanol, ethanol, gasoline, n-hexane, toluene, xylene, and tetrahydrofuran; the catalyst includes any one or any combination of ferrocene, nickel acetate, and cobalt acetate; and the reaction promoter includes any one or any combination of thiophene, sulfur, and organometallic molybdenum.

[0022] In some embodiments, the mixed feedstock can be any combination of the following: ethanol / ferrocene / sulfur, toluene / ferrocene / sulfur, xylene / ferrocene / sulfur, n-hexane / ferrocene / sulfur, xylene / ferrocene / thiophene, toluene / ferrocene / thiophene, n-hexane / ferrocene / thiophene, tetrahydrofuran / ferrocene / thiophene.

[0023] In some embodiments, the ratio of carbon source, catalyst, and reaction promoter can be: C:Fe = 10-1000:1 (molar ratio); S:Fe = 0.01-1:1 (molar ratio); where C is the carbon source, Fe is the catalyst, and S is the reaction promoter.

[0024] When applying these materials, the optimal combination of carbon source, catalyst, and reaction aids should be selected according to different needs to improve product quality, reduce costs, and increase economic benefits.

[0025] The preheating system 2 is a component used to preheat the carrier gas to prevent condensation when the cold carrier gas meets the gaseous mixture formed after heating and vaporization.

[0026] Carrier gas refers to the gas used to carry and dilute the gaseous mixed raw materials into the high-temperature reactor and participate in the reaction.

[0027] In some embodiments, the carrier gas includes hydrogen and other gases, and the other gases include any one or any combination of nitrogen, argon, and helium.

[0028] In some embodiments, the composition and volume ratio of the carrier gas are: hydrogen : other gases = 5%-100% : 95%-0%.

[0029] The preheating system 2 heats the carrier gas entering it to obtain heated carrier gas. In some embodiments, the preheating temperature of the carrier gas preheated by the preheating system 2 can be 300°C to 600°C.

[0030] In applications, the components of the aforementioned mixed raw materials and carrier gas are relatively easy to obtain, and their combination according to different needs helps to reduce costs. Therefore, the embodiments in this specification can not only synthesize carbon nanotubes, but also achieve low synthesis costs.

[0031] Figure 2 This is a structural schematic diagram of a preheating system and a high-temperature reactor according to some embodiments of this specification.

[0032] In some embodiments, such as Figure 1 and Figure 2 As shown, the preheating system 2 includes a low-temperature furnace 21, a metal pipe 22, an inlet pipe 23, and an outlet pipe 24. The metal pipe 22 is sleeved on the outer wall of the low-temperature furnace 21. The inlet end of the low-temperature furnace 21 is connected to the inlet pipe 23, and the outlet end of the low-temperature furnace 21 is connected to one end of the outlet pipe 24. The other end of the outlet pipe 24 is connected to the gas transmission pipeline 4.

[0033] In some embodiments, the metal pipe of the preheating system is 1000mm-2000mm long; the diameter of the air inlet pipe is 2mm-6mm, and the diameter of the air outlet pipe is 2mm-4mm.

[0034] The low-temperature furnace 21 is used to provide the heat source required for preheating the carrier gas; the metal pipe 22 is sleeved on the outer wall of the low-temperature furnace 21 to conduct heat; the carrier gas enters the low-temperature furnace 21 through the inlet pipe 23, is heated in the low-temperature furnace, and is output through the outlet pipe 24 to complete the preheating process.

[0035] In some embodiments, the furnace temperature of the low-temperature furnace 21 is 200℃—800℃.

[0036] In some embodiments, a first flow meter may be installed on the outlet pipe 24, and a second flow meter may be installed on the gas delivery pipe 4 between the pressure vessel 1 and the outlet pipe 24. The first flow meter is used to control the input flow rate of the gaseous mixed raw material, and the second flow meter is used to control the input flow rate of the heated carrier gas.

[0037] In some embodiments, the flow rate of the gaseous mixed raw material controlled by the first flow meter is 0.1L-10L / min; the flow rate of the heated carrier gas controlled by the second flow meter is 0.1L-50L / min.

[0038] In some embodiments, the first flow meter and / or the second flow meter may be a rotor flow meter. In application, using a rotor flow meter can improve the accuracy of flow control, reduce the difficulty of controlling the catalytic pyrolysis reaction, and improve the stability of the catalytic pyrolysis reaction.

[0039] Figure 3 This is a structural schematic diagram of a preheating system and a high-temperature reactor according to other embodiments of this specification.

[0040] In some embodiments, such as Figure 3 As shown, the preheating system 2 has a multi-layered nested folding sleeve structure, with the inner core of the folding sleeve structure being a capillary group. The folding sleeve structure is configured to force the carrier gas to flow repeatedly from the outside to the inside in each layer of pipeline, achieving efficient preheating of the carrier gas by increasing the diameter and gradually decreasing the pipe diameter.

[0041] The multi-layer nested folding sleeve structure consists of multiple coaxially arranged sleeve layers, forming an annular flow channel between adjacent sleeves, and the diameter of each flow channel gradually decreases from the outside to the inside; the carrier gas enters from the outermost flow channel, flows into the next inner flow channel through the folding connecting section at the end, and so on, eventually entering the inner core through the serpentine reciprocating flow channel.

[0042] A capillary assembly refers to a collection of parallel or series-parallel flow channels consisting of multiple small-diameter pipes located in the central region of a multi-layered nested folded sleeve structure. It is used to form a small-section flow path in the final stage to improve the carrier gas velocity and heat exchange efficiency.

[0043] Each sleeve layer and capillary assembly can be integrally processed or segmentally welded from heat-resistant metal tubing (such as stainless steel), and the outer periphery is equipped with a heating zone of a second heating module (see the relevant description below) to form a stable heat source for the pipe walls of each flow channel.

[0044] In some embodiments, the carrier gas inlet is located at the beginning of the outermost flow channel, and the communication ports between each layer are only provided at predetermined ends. Structurally, this restricts the carrier gas to enter the inner flow channels sequentially from the outer flow channels, layer by layer, and finally into the capillary assembly. Since the inlets and outlets of each adjacent flow channel are located at opposite ends, the carrier gas flows alternately in opposite directions within each flow channel, thus forming multiple reciprocating paths.

[0045] The multi-layered nested folded sleeve structure combined with the inner core capillary assembly, with a "from the outside to the inside, gradually decreasing pipe diameter, and multiple folds" design, extends the heating path of the carrier gas and increases the heat exchange area without increasing the external volume. The gradually decreasing pipe diameter also enhances the contact efficiency between the gas per unit volume and the pipe wall, enabling the carrier gas to be uniformly and efficiently heated to the required temperature in a short time, laying the foundation for stable mixing with gaseous raw materials.

[0046] High-temperature reactor 3 is the site where catalytic pyrolysis reaction occurs and carbon nanotubes are generated.

[0047] In some embodiments, such as Figures 1-3 As shown, the high-temperature reactor 3 includes a high-temperature furnace 31 and a quartz tube 32 disposed inside the high-temperature furnace 31. The pressure vessel 1 is connected to the quartz tube 32 via a gas supply pipe 4. The quartz tube 32 in the high-temperature reactor 3 serves as the reaction zone, where the gaseous mixed raw material output from the pressure vessel 1 and the heated carrier gas output from the preheating system 2 converge and undergo a catalytic pyrolysis reaction to generate carbon nanotubes.

[0048] In some embodiments, the heating temperature of the high-temperature reactor 3 is 1060°C–1300°C.

[0049] Carbon nanotubes refer to one-dimensional tubular carbon material aggregates with nanoscale dimensions that are grown in a high-temperature reactor 3 by cracking carbon sources through the action of a catalyst.

[0050] Gas pipeline 4 is a closed pipeline used to transport gaseous mixed raw materials and carrier gas. The outlet of pressure vessel 1 is connected to the inlet of high-temperature reactor 3 (i.e., the inlet of quartz tube 32) through gas pipeline 4, while the outlet of preheating system 2 is connected to gas pipeline 4 between pressure vessel 1 and high-temperature reactor 3.

[0051] In some embodiments, pressure vessel 1 is connected to high-temperature reactor 3 via gas pipeline 4, and preheating system 2 is connected to gas pipeline 4; pressure vessel 1, preheating system 2 and high-temperature reactor 3 are connected internally; gaseous mixed raw material formed after heating and gasification is output from pressure vessel 1, and after merging with heated carrier gas output from preheating system 2 in gas pipeline 4, they enter high-temperature reactor 3 together.

[0052] The above embodiments, by setting up a first flow meter and a second flow meter, realize the monitoring and manual or semi-automatic adjustment of the flow rates of the gaseous mixed raw material and the heated carrier gas, ensuring that the gaseous mixed raw material and the heated carrier gas can be delivered synchronously according to a preset ratio. However, the use of a manual flow meter and open-loop heating control lacks the ability to perceive and control the gasification state, component drift, and pipeline condensation in real time.

[0053] To address the aforementioned issues, this specification's embodiments, while retaining and optimizing the aforementioned physical synthesis components, introduce a sensing and monitoring array, an execution drive unit, and a controller to form an intelligent closed-loop control system, thereby significantly improving the stability and product quality of carbon nanotube synthesis.

[0054] The sensor monitoring array is a collection of data acquisition units consisting of multiple sensors, used to provide real-time operating condition data such as temperature and pressure to the controller. The sensor monitoring array includes a first temperature sensor, a first pressure sensor, a second temperature sensor, and a third temperature sensor.

[0055] In some embodiments, such as Figure 1 As shown, the sensing and monitoring array includes a first temperature sensor 11 and a first pressure sensor 12 disposed inside the pressure vessel 1, a second temperature sensor 13 disposed at the outlet of the preheating system 2, and a third temperature sensor 14 disposed inside the high-temperature reactor 3; the execution drive unit includes a first heating module 10 disposed outside the pressure vessel 1, a first electrically controlled valve 8 disposed on the gas pipeline 4 and located between the outlet of the pressure vessel 1 and the access point of the preheating system 2, and a first flow controller 15 disposed on the gas pipeline 4; and the controller is electrically connected to the sensing and monitoring array and the execution drive unit.

[0056] The first temperature sensor 11 is installed inside the pressure vessel 1 to collect the temperature inside the pressure vessel 1.

[0057] The second temperature sensor 13 is located at the outlet of the preheating system 2 and is used to collect the temperature of the heated carrier gas.

[0058] The third temperature sensor 14 is installed inside the high-temperature reactor 3 to collect the temperature inside the high-temperature reactor 3. For example, the first temperature sensor, the second temperature sensor, and the third temperature sensor can all be K-type thermocouples, etc.

[0059] The first pressure sensor 12 is disposed inside the pressure vessel 1 and is used to collect the pressure inside the pressure vessel 1. For example, the first pressure sensor can be a piezoresistive pressure transmitter, etc.

[0060] In some embodiments, the sensor monitoring array is used to collect device status data.

[0061] Device status data refers to real-time measurement data collected by the sensor monitoring array that reflects the operating conditions of each component of the device. In some embodiments, device status data includes container temperature data collected by the first temperature sensor, container pressure data collected by the first pressure sensor, carrier gas temperature data collected by the second temperature sensor, and high-temperature reactor temperature data collected by the third temperature sensor. Device status data may further include mass change rate collected by the weighing module, pipe wall temperature data collected by the heat flux sensor, average fluid density collected by the gas density meter, current fluid pressure, current fluid temperature, combustible gas concentration, pipeline pressure data, flow resistance monitoring data, etc. For related explanations of the above data, please refer to the relevant descriptions below.

[0062] To enable intervention in the physical process, the carbon nanotube synthesis device is equipped with an execution drive unit. The execution drive unit is an assembly of actuators consisting of a first heating module, a first electrically controlled valve, and a first flow controller, used to change the heating, output start / stop, and conveying flow status of the mixed raw materials under the controller's command.

[0063] The first heating module 10 is disposed outside the pressure vessel 1 and is used to provide adjustable heat energy for the gasification of the mixed raw materials. For example, the first heating module can be an electric heating jacket or a heating belt. The output terminal of the controller is connected to the power controller (such as a solid-state relay) of the first heating module to adjust its heating power.

[0064] The first electrically controlled valve 8 is installed on the gas transmission pipeline 4 and located between the outlet of the pressure vessel 1 and the inlet of the preheating system 2. It is used to control the output of the gaseous mixed raw material, that is, to control whether the gaseous mixed raw material in the pressure vessel enters the gas transmission pipeline. For example, the first electrically controlled valve can be a solenoid valve. The controller is connected to the drive circuit of the first electrically controlled valve to control its opening or closing.

[0065] The first flow controller 15 is installed on the gas transmission pipeline 4 and is used to regulate the total output flow rate of the gaseous mixed raw material. For example, the first flow controller can be an electronic mass flow controller, etc. The controller is connected to the first flow controller to control its valve opening.

[0066] In some embodiments, the execution drive unit is used to adjust the device operating parameters.

[0067] Device operating parameters refer to controllable parameters that are adjustable by the drive unit and affect the device's operating state. In some embodiments, device operating parameters include the heating power of the first heating module, the opening and closing status of the first solenoid valve, and the valve opening degree of the first flow controller. Device operating parameters may further include the opening and closing status of the second solenoid valve, the drive duty cycle of the second heating module, the opening degree of the electro-hydraulic pressure regulating valve, the heating power of the gas heater, the opening and closing of the venting solenoid valve and the purging solenoid valve, and the pulse current frequency of the high-frequency excitation coil. For related explanations of the above data, please refer to the relevant descriptions below.

[0068] A controller is a control core electrically connected to the sensor monitoring array and the execution drive unit. It is used to receive sensor data, perform derivative rate of change calculations, determine the critical vaporization point, control overheating, and output control commands. For example, a controller can be a PLC (Programmable Logic Controller) or an industrial MCU (Microcontroller Unit), etc.

[0069] The controller can establish electrical connections with the sensor monitoring array and actuation drive unit through analog input / output modules or fieldbus connections. Furthermore, the controller pre-stores data such as saturation pressure models, fractionation prediction models, fractionation enrichment tables, stage-weight mapping tables, and databases corresponding to the mixed raw materials at different temperatures, for use during control processes. See the relevant descriptions below for details.

[0070] In some embodiments, the controller is configured to: assess the gasification process of the mixed feedstock and / or the transport status of the mixed feedstock in the gas pipeline based on device status data; and control the execution drive unit to adjust the device operating parameters in response to the gasification process and / or transport status meeting preset conditions, so as to lock the supply amount of components entering the high-temperature reactor and / or ensure the transport stability of the mixed feedstock in the gas pipeline.

[0071] The vaporization process refers to the degree to which the mixed raw material in the pressure vessel transforms from a liquid to a gaseous state, including stages such as the liquid phase, critical vaporization point, and superheated state. The transport state refers to the physical state of the gaseous mixed raw material as it flows in the gas pipeline, including whether condensation occurs, whether there is a risk of coking, whether the components are stable, and whether there are leaks or blockages.

[0072] In some embodiments, the controller evaluates the gasification process of the mixed raw material and / or the transport status of the mixed raw material in the gas pipeline based on the device status data, including: acquiring temperature data and pressure data inside the container through a first temperature sensor and a first pressure sensor, calculating the rate of change of pressure with temperature, and determining whether the pressure vessel has reached the critical gasification point; acquiring the average fluid density through a gas density meter and determining whether the average fluid density is greater than a preset density threshold; acquiring the combustible gas concentration through a combustible gas detector and acquiring pipeline pressure data through a pressure sensor to determine whether abnormal conditions are met; and determining whether preset coking conditions are met through flow resistance monitoring data, etc. For detailed explanations of this part, please see the relevant description below.

[0073] The preset conditions corresponding to the vaporization process include: the rate of change of pressure with temperature meets the first preset condition (determining that the critical vaporization point has been reached), and the temperature data inside the container reaches the preset superheating temperature (determining that vaporization is complete and superheating is sufficient, and the first solenoid valve can be opened for output), etc.

[0074] The preset conditions corresponding to the delivery status include: average fluid density greater than a preset density threshold (indicating increased mixed gas concentration, requiring increased heating gas supply capacity); pipe wall heat absorption rate lower than a preset heat balance threshold (indicating sufficient preheating of the gas pipeline, allowing the first solenoid valve to be opened); carrier gas temperature data equal to the target preheating temperature (indicating carrier gas preheating ready, allowing the second solenoid valve to be opened for pipeline preheating); combustible gas concentration and / or pipeline pressure data meeting abnormal conditions (indicating leakage or pressure runaway, triggering purging); deviation meeting drift conditions (indicating micro-leakage, triggering safety replacement action); and flow resistance monitoring data meeting preset coking conditions (indicating carbon buildup inside the pipe, triggering decarbonization operation), etc. See the relevant descriptions below for details.

[0075] In response to the gasification process and / or conveying status meeting preset conditions, the control and execution drive unit adjusts the operating parameters of the device to lock the supply of components entering the high-temperature reactor and / or ensure the conveying stability of the mixed raw materials in the gas pipeline. This includes: generating a power adjustment signal to drive the first heating module to continue heating to a preset superheat temperature; generating a first drive command to open the first electrically controlled valve; driving the valve opening of the first flow controller based on a preset molar ratio to lock the absolute molar supply of key components; fine-tuning the opening of the first flow controller based on the fractionation enrichment degree to compensate for enrichment errors; generating a second drive command to open the second electrically controlled valve for pipeline preheating; and using PID control... The proportional-integral-derivative (PID) algorithm is used to adjust the drive duty cycle of the second heating module; the gas heater is controlled to heat the inert gas to the target temperature, and the electro-hydraulic pressure regulating valve is controlled to open to the target opening degree so that the tracing gas is pumped into the sealed annular jacket; the tracing gas is pumped into the buffer section, shielding section, and excitation section at the first pressure and first temperature, the second pressure and second temperature, and the third temperature, respectively; the venting solenoid valve and the purging solenoid valve are opened to perform purging; the safe replacement action of the tracing gas is triggered; an isobaric hot gas seal is established and pulsed venting is performed; a high-frequency pulse current is injected into the high-frequency excitation coil to remove carbon.

[0076] In some embodiments, the controller may be further configured to perform the following operations to control the gasification and conveying states of the mixed raw materials: acquiring container temperature data fed back by a first temperature sensor and container pressure data fed back by a first pressure sensor; calculating the rate of change of pressure with temperature based on the container temperature data and container pressure data; determining that the pressure container 1 has reached a critical gasification point in response to the rate of change satisfying a first preset condition; generating and outputting a power adjustment signal to drive the first heating module to continue heating until the container temperature data reaches a preset superheated temperature, which is higher than the theoretical boiling point of the highest boiling point component in the mixed raw materials; after the container temperature data reaches the preset superheated temperature, generating a first drive command to open the first electrically controlled valve, and driving the valve opening of the first flow controller based on the preset molar ratio of the components of the mixed raw materials, thereby adjusting the total output flow of the gaseous mixed raw materials to lock the absolute molar supply of the key components entering the high-temperature reactor 3, and sending the mixed gas flow formed by the merging of the gaseous mixed raw materials and the heated carrier gas into the high-temperature reactor 3. (For more information on this part, please refer to...) Figure 5 Related descriptions.

[0077] Figure 4 This is a flowchart illustrating the use of a carbon nanotube synthesis apparatus according to some embodiments of this specification.

[0078] In some embodiments, such as Figure 4As shown, the carbon nanotube synthesis apparatus is used as follows: First, the mixed raw material 5 is placed into the pressure vessel 1. The mixed raw material 5 includes a carbon source, a catalyst, and a reaction aid. Then, the pressure vessel 1 is heated and pressurized to obtain a gaseous mixed raw material. At the same time, the carrier gas 6 is input into the preheating system 2 to preheat the carrier gas 6, thereby obtaining a heated carrier gas. Subsequently, the gaseous mixed raw material and the heated carrier gas obtained above are input together into the high-temperature reactor 3, and the high-temperature reactor 3 is heated to obtain carbon nanotubes 7.

[0079] In application, the carbon source, catalyst, and reaction aids are first mixed according to the required proportions to form a mixed raw material. This mixed raw material is then placed into a pressure vessel, which is heated and pressurized. Under high temperature and pressure, the mixed raw material is vaporized into molecules of varying sizes. The vaporized molecules are uniformly mixed together to obtain a gaseous mixed raw material. Simultaneously, hydrogen and other gases are mixed according to the required proportions to form a carrier gas, which is introduced into a cryogenic furnace through the inlet. The cryogenic furnace is heated using metal pipes to preheat the carrier gas, resulting in a heated carrier gas. The vaporization and preheating processes are performed simultaneously, significantly reducing operational steps and time. After the vaporization and preheating processes are completed, the mixture is then... The control of the first electrically controlled valve ensures that the gaseous mixed raw material and the heated carrier gas achieve the optimal ratio. The gaseous mixed raw material and the heated carrier gas are fed together into a high-temperature reactor, where the reactor is heated. Simultaneously, the mixed raw material grows on a quartz tube to obtain carbon nanotubes. Because the mixed raw material is uniformly vaporized and then simultaneously introduced into the high-temperature reactor, uneven carbon nanotube reaction is avoided due to sequential entry into the reactor, improving reaction uniformity. This results in synthesized carbon nanotubes of uniform quality and high purity, and avoids the reduction in synthesis efficiency caused by requiring different vaporization operations for different raw materials. This not only saves operation time and improves operation efficiency but also enhances the quality of carbon nanotubes. Therefore, the embodiments in this specification not only exhibit high efficiency in catalytic growth of carbon nanotubes but also produce high-quality synthesized carbon nanotubes.

[0080] At each stage of this method of use, the controller performs closed-loop intelligent control of the gasification, preheating, conveying and reaction processes by executing the drive unit based on feedback from the sensor monitoring array.

[0081] Figure 5 This is a flowchart illustrating a carbon nanotube synthesis method according to some embodiments of this specification. This method is the core control logic executed by the controller in the aforementioned carbon nanotube synthesis apparatus, aiming to solve the problems of ambiguous determination of the gasification state of the mixed raw materials, inaccurate timing of gaseous mixed raw material output, and unstable mixed raw material ratio in traditional methods. This method is executed by the controller, and the corresponding process 500 includes steps 510 to 550.

[0082] Step 510: Obtain the container internal temperature data fed back by the first temperature sensor and the container internal pressure data fed back by the first pressure sensor.

[0083] The container internal temperature data refers to the parameter characterizing the temperature of the vaporization space inside the pressure vessel 1, which is collected in real time by the first temperature sensor. In some embodiments, the controller can read the container internal temperature data T(i) uploaded by the first temperature sensor in real time, where i represents the sampling time, and the sampling time interval between adjacent sampling times is a fixed sampling period, which can be preset manually, for example, 0.2s or 1s.

[0084] The container internal pressure data refers to the parameters characterizing the internal pressure of pressure vessel 1, which are collected in real time by the first pressure sensor. In some embodiments, the controller can read the container internal pressure data P(i) uploaded by the first pressure sensor in real time.

[0085] Step 520: Calculate the rate of change of pressure with temperature based on the temperature data and pressure data inside the container.

[0086] The rate of change of pressure with temperature is the derivative of pressure data with respect to temperature data, i.e., dP / dT. It characterizes the degree of drastic change in pressure with temperature during the heating process of pressure vessel 1.

[0087] In some embodiments, the controller can calculate the rate of change of pressure with temperature using the discrete difference method based on the container's internal temperature and pressure data. For example, the rate of change of pressure with temperature is K(i) = [P(i) - P(i-1)] / [T(i) - T(i-1)]. To avoid single-point fluctuations, the controller performs window smoothing on the calculated K(i) at multiple sampling times to obtain a stable rate of change sequence Ks(i).

[0088] Step 530: In response to the change rate satisfying the first preset condition, it is determined that the pressure vessel 1 has reached the critical vaporization point.

[0089] If the rate of change meets the first preset condition, it means that the liquid mixture in pressure vessel 1 has been basically completely vaporized.

[0090] The first preset condition is the condition for determining that the mixed raw materials have completed the liquid-gas phase transition. In some embodiments, the controller continuously monitors the rate of change sequence Ks(i), continuously calculates the mean K_pre of Ks(i) from time 0 to time i / 2 and the mean K_post of Ks(i) from time i / 2 to time i. When the decrease (K_pre-K_post) reaches or exceeds the preset step threshold ΔK_step, Ks(i) is continuously read within the first preset time window Tw. If all Ks(i) within the first preset time window Tw satisfy |Ks(i)-K_post|≤ the preset low-level fluctuation threshold δK, then the rate of change is confirmed to meet the first preset condition. The first preset time window, the preset step threshold, and the preset low-level fluctuation threshold can be manually preset.

[0091] The critical vaporization point is the moment when the liquid phase completely disappears and the mixed raw materials change from a liquid state or a liquid-gas mixture state to a fully gaseous state.

[0092] In some embodiments, the controller records the moment when the rate of change meets a first preset condition as the critical vaporization point t_c.

[0093] If the rate of change does not meet the first preset condition, it means that the mixed raw materials have not been completely gasified. The controller will continue to heat and monitor without performing any subsequent operations until the rate of change meets the first preset condition.

[0094] Step 540: In response to the critical vaporization point being reached inside the pressure vessel 1, a power adjustment signal is generated and output to drive the first heating module to continue heating until the temperature data inside the vessel reaches the preset superheat temperature.

[0095] When the critical vaporization point is reached inside pressure vessel 1, it means the liquid mixture has just disappeared. However, tiny droplets or unsublimated solid catalyst particles may still be suspended inside pressure vessel 1, and stable superheated vapor has not yet formed. Further heating is required to completely vaporize it and ensure superheating to prevent condensation during subsequent transport. At this time, the controller does not immediately open the first electrically controlled valve, but instead generates a power regulation signal.

[0096] The power adjustment signal is a control signal sent by the controller to the first heating module, used to set or adjust the heating power of the first heating module.

[0097] The controller drives the first heating module to continue heating, aiming to push the temperature inside the container to the preset superheated temperature. The preset superheated temperature is higher than the theoretical boiling point of the highest-boiling component in the mixture. This preset superheated temperature is a pre-set value stored in the controller. For example, if the highest-boiling component in the mixture is ferrocene, with a theoretical boiling point of approximately 249°C, the preset superheated temperature can be 20°C-30°C higher to ensure that all components in the mixture exist in a stable superheated gaseous state.

[0098] If the critical vaporization point is not reached in pressure vessel 1, it indicates that a large amount of liquid is still present. The controller will maintain the current heating state and continue heating without executing the overheating step.

[0099] Step 550: After the temperature data inside the container reaches the preset superheat temperature, a first driving command is generated to open the first electrically controlled valve, and the valve opening of the first flow controller is driven based on the preset molar ratio of the components of the mixed raw materials. The total output flow of the gaseous mixed raw materials is adjusted to lock the absolute molar supply of the key components entering the high-temperature reactor 3, and the mixed gas flow formed by the gaseous mixed raw materials and the heated carrier gas is sent into the high-temperature reactor 3.

[0100] Once the temperature inside the container reaches the preset superheat temperature, the controller generates the first drive command. The first drive command is a valve opening control command issued by the controller after confirming that the preset superheat temperature has been reached. It is used to open the first electrically controlled valve, switching it from the closed state to the open state, thus establishing an output path for the gaseous mixed raw material.

[0101] The components of a mixed raw material refer to the types and proportions of each substance in the mixed raw material. Simultaneously with opening the first electrically controlled valve, the controller will drive the valve opening of the first flow controller based on the preset molar ratio of the components of the mixed raw material.

[0102] The preset molar ratio refers to the ideal molar proportions of key components in the gaseous mixed raw material entering the high-temperature reactor 3, determined during the process development stage to ensure optimal growth of carbon nanotubes. For example, the molar ratio of carbon source to catalyst (C:Fe) is set to 100:1, and the molar ratio of sulfur to iron (S:Fe) is set to 0.5:1. The preset molar ratio is determined manually in advance and stored in the controller.

[0103] Valve opening degree refers to the amount of opening action of the regulating valve inside the first flow controller relative to the fully open state. For example, a valve opening degree of 50% means that the valve is opened to 50% of its fully open state.

[0104] Key components refer to precursor substances in the mixed feedstock that play a decisive role in the growth of carbon nanotubes and whose concentration is prone to drift during gasification due to differences in volatile partial pressure. In this specification, key components refer to catalyst precursors (such as ferrocene) or their decomposition products.

[0105] Absolute molar supply refers to the number of moles of the key components that need to enter the high-temperature reactor 3 per unit time in order to maintain a constant ratio. It is a process target that needs to be locked by controlling the total output throughput of the gaseous mixed raw materials.

[0106] The total output flux of the gaseous mixed feedstock refers to the total volume or mass flow rate of the gaseous mixed feedstock output per unit time, as regulated by the first flow controller.

[0107] Due to the component fractionation effect during the continuous output of the mixed raw materials, the actual molar concentration of key components in the gaseous mixed raw materials dynamically drifts over time. The controller does not directly change the component ratio of the gas in the pressure vessel, but instead executes "flow-concentration compensation" logic to lock the absolute molar supply: the controller estimates the actual molar concentration of key components in the gaseous mixed raw materials in real time based on the subsequently determined fractionation enrichment degree; based on the actual molar concentration and the absolute molar supply, it calculates the required total output flux setpoint of the gaseous mixed raw materials in reverse. The total output flux setpoint refers to the total volume or mass flow rate of the gaseous mixed raw materials that the first flow controller needs to output per unit time to achieve the absolute molar supply; the controller generates corresponding control commands and sends them to the first flow controller to drive its internal regulating valve to reach the corresponding valve opening, thereby achieving precise adjustment of the total output flux of the gaseous mixed raw materials and locking the absolute molar supply of key components entering the high-temperature reactor 3.

[0108] The embodiments in this specification accurately identify the critical vaporization point by using the rate of change of the derivative of pressure with respect to temperature. After the liquid phase has completely disappeared, the temperature is continued to be heated to the superheated temperature. Then, the first electrically controlled valve is opened and the gaseous mixed raw material is output. At the same time, the total output throughput is dynamically controlled based on the preset molar ratio to lock the absolute molar supply of key components. This can significantly reduce droplet entrainment and transport condensation, improve the stability and compositional consistency of the mixed raw material when it enters the high-temperature reactor, and thus facilitate the continuous preparation of carbon nanotube aggregates with more stable quality.

[0109] Furthermore, in order to address the component fractionation effect caused by the different volatilization rates of the components in the mixed raw materials during continuous production, pressure vessel 1 is mounted on a weighing module. The weighing module is connected to the controller signal to monitor the rate of mass change of the mixed raw materials in pressure vessel 1, so that the controller can obtain mass change data to characterize the component fractionation effect, thereby enabling real-time assessment and active suppression of the fractionation state.

[0110] In some embodiments, the controller is further configured to: determine the fractionation enrichment state of the components of the mixed raw material in the pressure vessel 1 based on the temperature data, pressure data and mass change rate in the container, using a fractionation prediction model; and adjust the heating power of the first heating module based on the fractionation enrichment state to compensate for the output concentration fluctuations caused by the difference in volatile partial pressure of different components, thereby suppressing the component fractionation effect in the pressure vessel 1.

[0111] like Figure 1 As shown, the weighing module 16 is a weight detection unit located at the bottom of the pressure vessel 1, used to measure the mass data M(i) of the pressure vessel and the mixed raw materials inside it. For example, the weighing module can be a high-precision weight sensor (such as a strain gauge load cell).

[0112] To prevent thermal drift during the operation of the first heating module from affecting weighing accuracy, a heat insulation pad 17 is installed between the weighing module and the pressure vessel base (e.g., Figure 1 As shown in the figure, zero-point drift correction is performed on the symmetrical weighing signal within the controller.

[0113] The rate of mass change refers to the amount of mass loss per unit time calculated by the controller based on the mass data output by the weighing module, and is used to characterize the gasification output speed of the mixed feedstock. For example, the rate of mass change Vm_raw(i) = [M(i-1) - M(i)] / Δt, where Δt is the sampling time interval, i.e., the sampling period. To avoid instantaneous fluctuations interfering with the subsequent fractionation prediction model, the controller performs a moving average on the calculated Vm_raw(i) to obtain a smoothed rate of mass change Vm(i).

[0114] Fractionation prediction models are machine learning models used to determine fractionation enrichment states. For example, a fractionation prediction model can be a trained back propagation (BP) neural network or a support vector machine model.

[0115] In some embodiments, the fractionation prediction model takes the container temperature data, container pressure data, and mass change rate as inputs and outputs the fractionation enrichment state of the components of the mixed feedstock in pressure vessel 1.

[0116] Fractionation enrichment state refers to the qualitative description and classification of the degree of component shift caused by the fractionation effect during the continuous gasification of a mixed feedstock. For example, fractionation enrichment state can be classified into "equilibrium output state", "premature escape state of light components", "accumulation and enrichment state of heavy components", and "critical risk state of condensation".

[0117] The equilibrium output state refers to a state in which the temperature and pressure data inside the container are in high agreement with the saturated pressure model, the content of key components in the gaseous mixed feedstock is within the fluctuation range allowed by the preset molar ratio, and there is no significant tendency for fractionation.

[0118] Premature escape of light components refers to a state in which, during the initial stage of gasification, excessively rapid heating or inaccurate temperature control leads to the large-scale gasification and escape of light components such as carbon sources. This results in a temporarily high concentration of carbon sources in the gaseous mixture, while the concentration of heavy components begins to accumulate within pressure vessel 1. Light components refer to components in the mixture with lower boiling points that are preferentially gasified, such as carbon sources. Heavy components refer to components in the mixture with higher boiling points that are difficult to gasify, such as catalysts.

[0119] The accumulation and enrichment state of heavy components refers to the state in which, after a large amount of light components are consumed in the middle and late stages of gasification, the concentration of heavy components such as catalyst in pressure vessel 1 increases significantly, resulting in the proportion of key components in the gaseous mixed feedstock exceeding the preset molar ratio.

[0120] The critical risk state of condensation refers to the state in which the concentration of heavy components in pressure vessel 1 is too high, and there is a high risk of condensation and precipitation of gaseous mixed raw materials during subsequent transportation.

[0121] In some embodiments, the training process of the fractionation prediction model is as follows: During the device development stage, the true component concentrations of key components in the gaseous mixed feedstock at different times under different operating conditions are obtained through pre-experiments using online mass spectrometry analysis or condensation sampling detection; the measured true component concentrations are compared with the preset molar ratio in real time to calculate the relative deviation percentage of component concentrations; the continuous concentration deviation value sequence (i.e., the sequence composed of the relative deviation percentages of component concentrations at different times) is divided into several discretized state levels corresponding to each category of fractionation enrichment state, and each is assigned a corresponding classification label; finally, these classification labels are synchronized with the physical feature data such as container temperature data, container pressure data, mass change rate, and cumulative mass loss (see description below) recorded at the corresponding sampling time according to the timestamp, to construct a feature-label mapping dataset for supervised learning training of the model, which includes a large number of training samples and training labels.

[0122] In some embodiments, multiple training samples with training labels are input into an initial fractionation prediction model. A loss function is constructed based on the training labels and the results of the initial fractionation prediction model. The parameters of the initial fractionation prediction model are iteratively updated based on the loss function using gradient descent or other methods. Training is completed when preset training conditions are met, resulting in a trained fractionation prediction model. These preset training conditions may include loss function convergence, the number of iterations reaching a threshold, etc.

[0123] In some embodiments, the controller dynamically adjusts the heating power of the first heating module based on the fractionation enrichment state predicted by the fractionation prediction model. For example, when it is determined to be a "premature escape state of light components," the heating power is appropriately reduced to slow down the volatilization of light components; when it is determined to be a "cumulative enrichment state of heavy components," the heating power is increased to forcibly increase the saturated vapor pressure of heavy components and promote their output; when it is determined to be a "critical risk state of condensation," the controller fine-tunes the heating power and maintains the superheated state, while simultaneously reducing the valve opening of the first electrically controlled valve to prioritize ensuring that the gaseous mixed raw material in pressure vessel 1 does not undergo internal condensation and precipitation, and by reducing the flow rate in conjunction with the adjustment of the heating power. The adjustment range of the heating power can be preset manually.

[0124] Volatile partial pressure difference refers to the different tendencies and abilities of different components to change from liquid or solid to gas at the same temperature.

[0125] Output concentration fluctuation refers to the phenomenon that the relative content of each component in the gaseous mixed raw material output per unit time deviates from the preset molar ratio due to the difference in the volatilization partial pressure of different components.

[0126] The component fractionation effect refers to the phenomenon that during the continuous gasification of a mixed feedstock, lighter components such as carbon sources preferentially escape while heavier components such as catalysts relatively accumulate, resulting in a gradual deviation of the residual liquid phase and subsequent output gaseous mixed feedstock components from a preset molar ratio. In some embodiments, the controller can actively compensate for differences in volatile partial pressure by dynamically adjusting the heating power of the first heating module, thereby suppressing the component fractionation effect.

[0127] The embodiments in this specification introduce a weighing module and incorporate the rate of mass change into the heating control. This can suppress the component fractionation effect caused by the preferential volatilization of light components at the source without adding complex online component analysis equipment, thereby improving the component stability in the continuous gasification stage and enhancing the consistency of the gaseous mixed raw materials that subsequently enter the high-temperature reactor.

[0128] Furthermore, in addition to suppressing fractionation at the source, it is also necessary to accurately compensate for component drift that has already occurred during the output process. To this end, the controller is also configured to perform a dynamic component compensation operation based on the component fractionation effect.

[0129] In some embodiments, the controller has a pre-stored saturation pressure model of the mixed raw material at different temperatures; the controller is further configured to: acquire the theoretical saturation pressure value corresponding to the temperature data inside the container during the process of the first electrically controlled valve opening and continuously outputting the gaseous mixed raw material; determine the temperature-pressure deviation based on the pressure data inside the container and the theoretical saturation pressure value; determine the fractionation enrichment degree of the mixed raw material in the pressure vessel 1 based on the system running time and the temperature-pressure deviation; and generate a component correction command based on the fractionation enrichment degree and transmit it to the first flow controller, thereby adjusting the total output flow of the gaseous mixed raw material by finely adjusting the opening of the internal regulating valve of the first flow controller to compensate for the enrichment error of the key components entering the high-temperature reactor 3.

[0130] The saturation pressure model is a pre-stored function model or lookup table within the controller that characterizes the theoretical saturation pressure of the mixed feedstock at different temperatures. The saturation pressure model can be implemented using any of the following methods: empirical fitting formula, piecewise polynomial, or temperature-pressure lookup table. For example, for a given mixed feedstock, the saturation pressure model defines a theoretical saturation pressure of 2.5 MPa at 200°C and 4.0 MPa at 250°C. The saturation pressure model can be pre-determined and stored in the controller through experimental data fitting or theoretical calculation during the equipment commissioning or mixed feedstock formulation setting phase.

[0131] The theoretical saturation pressure value refers to the saturated vapor pressure that the mixed raw material should reach at a specific temperature under ideal equilibrium conditions. It is used as a reference benchmark to determine whether the current actual gasification state deviates from the ideal state. When the first electrically controlled valve opens and continuously outputs gaseous mixed raw material, the controller reads the temperature data T(i) inside the container in each sampling cycle and inputs it into the saturation pressure model to obtain the corresponding theoretical saturation pressure value Psat(i).

[0132] Temperature-pressure deviation refers to the deviation of the pressure data inside the container from the theoretical saturation pressure value, and is used to characterize the difference between the current state of the mixed feedstock and the ideal gasification equilibrium state.

[0133] In some embodiments, the controller can determine the temperature-pressure deviation based on the pressure data inside the container and the theoretical saturation pressure value. For example, the formula for calculating the temperature-pressure deviation is Dtp(i) = [P(i) - Psat(i)] / Psat(i), where P(i) is the pressure data inside the container and Psat(i) is the theoretical saturation pressure value. If Dtp(i) is consistently positive, it indicates that the current pressure data inside the container is higher than the ideal state; if it is consistently negative, it indicates that it is relatively lower.

[0134] The system running time refers to the cumulative continuous running time from the moment the first solenoid valve opens and begins to continuously output gaseous mixed raw materials. The controller starts accumulating the system running time from the moment the first solenoid valve opens, t_run(i) = t(i) - t_open, where t(i) is the current sampling time.

[0135] Fractionation enrichment is a parameter that quantitatively characterizes the segregation depth of key components in the output gaseous mixed feedstock relative to a preset molar ratio. The higher the value, the more severe the component deviation.

[0136] In some embodiments, the controller determines the current fractionation enrichment level by combining system operating time and temperature / pressure deviation. For example, the controller has a pre-stored fractionation enrichment level table, constructed using a matrix structure. This table divides the system operating time into several stages such as "initial," "middle," and "late," and classifies the temperature / pressure deviation into several levels such as "normal," "slight deviation," and "significant deviation," forming multiple orthogonal control quadrants. The specific values ​​in the table are obtained based on historical experimental calibration, and the construction principle follows the physical characteristic that "late stage has a higher weight than early stage, and high deviation has a higher weight than low deviation." The controller retrieves the corresponding fractionation enrichment level E_frac(i) from this table based on the current system operating time and temperature / pressure deviation. The fractionation enrichment level is a dimensionless value; a higher value indicates a more severe deviation of the component.

[0137] Furthermore, in order to more accurately assess the fractionation risk caused by the component fractionation effect, the controller also incorporates cumulative mass loss and real-time stage characteristics for weighted correction when determining the degree of fractionation enrichment.

[0138] In some embodiments, when determining the degree of fractionation enrichment, the controller is further configured to perform the following operations: obtain the cumulative mass loss fed back by the weighing module; determine the real-time stage characteristics of the gaseous mixed feed output based on the cumulative mass loss; retrieve the fractionation correction weights corresponding to the real-time stage characteristics, and weight the temperature and pressure deviations based on the fractionation correction weights to obtain the weighted deviation; and determine the degree of fractionation enrichment based on the weighted deviation.

[0139] The cumulative mass loss refers to the decrease in the total mass of the pressure vessel detected by the weighing module relative to the initial total mass since the first solenoid valve opens and begins to continuously output gaseous mixed raw materials. At the moment the first solenoid valve opens (t_open), the controller records the initial total mass M0; thereafter, in each sampling cycle, it reads the current mass data M(i) and calculates the cumulative mass loss ΔM_acc(i) = M0 - M(i). The cumulative mass loss directly reflects the total amount of mixed raw materials output, and therefore reflects the consumption process of the mixed raw materials better than the system running time.

[0140] Real-time stage characteristics are labels or parameters that characterize the current stage of the gaseous feedstock output. For example, real-time stage characteristics may include the initial output stage, the intermediate stable stage, and the late enrichment stage. In some embodiments, the controller can compare the cumulative mass loss ΔM_acc(i) with preset stage division thresholds (such as M1, M2, where M1 < M2, which can be set manually based on experience): when ΔM_acc(i) < M1, it is determined to be the initial output stage; when M1 ≤ ΔM_acc(i) < M2, it is determined to be the intermediate stable stage; and when ΔM_acc(i) ≥ M2, it is determined to be the late enrichment stage. This division allows the controller to distinguish the different fractionation risks represented by the same temperature and pressure deviation at different feedstock consumption stages.

[0141] Fractionation correction weights are preset weight coefficients for different real-time stage characteristics, used to adjust the influence of temperature and pressure deviations on the calculation of fractionation enrichment. The controller internally stores a stage-weight mapping table. In this table, the initial output stage corresponds to a fractionation correction weight w1=1, the intermediate stable stage corresponds to a fractionation correction weight w2=1.5, and the later enrichment stage corresponds to a fractionation correction weight w3=3, satisfying w1<w2<w3 to reflect the higher risk of fractionation in later stages. The stage-weight mapping table and its fractionation correction weight values ​​can be obtained and adjusted through experimental calibration during the device commissioning phase. After determining the characteristics of the current real-time stage, the controller can query and retrieve the corresponding fractionation correction weight w from the stage-weight mapping table.

[0142] The weighted deviation is the temperature and pressure deviation after fractionation correction weighting, which better reflects the fractionation risk at the current stage. In some embodiments, the controller retrieves the corresponding fractionation correction weight w based on the characteristics of the current real-time stage, and then multiplies the temperature and pressure deviation Dtp(i) by the fractionation correction weight to obtain the weighted deviation D_wt(i) = w·Dtp(i).

[0143] In some embodiments, the controller uses the weighted deviation D_wt(i) instead of the original temperature and pressure deviation Dtp(i) as input, and combines it with the system running time to look up the final fractionation enrichment level E_frac(i) in the fractionation enrichment level table. By introducing fractionation correction weights, in the later stages, the same temperature and pressure deviation will be given a higher fractionation enrichment interpretation strength, making the compensation control more consistent with the physical process of mixed feedstock consumption, and greatly improving the accuracy of identifying heavy component enrichment under high-risk conditions in the later stages.

[0144] This embodiment incorporates the cumulative mass loss into the fractionation assessment, allowing the stage information of mixed feedstock consumption to be included in the control decision. This makes the fractionation assessment no longer solely dependent on instantaneous temperature and pressure deviations, thereby significantly improving the accuracy of identifying the risk of enrichment of heavy components in the later stages and enhancing the pertinence of dynamic compensation.

[0145] The component correction command is a correction control signal sent by the controller to the first flow controller. It is used to adjust the total output flux of the gaseous mixed feedstock by increment or decrement based on the current flow setpoint of the first flow controller. The current flow setpoint refers to the target flow value that the controller calculates in real time and sends to the first flow controller to lock the absolute molar supply of the key components.

[0146] In some embodiments, the controller generates a component correction command based on the fractionation enrichment degree E_frac(i). For example, the controller can calculate the corrected opening degree ΔO = Kc·E_frac(i) of the internal regulating valve of the first flow controller based on the fractionation enrichment degree E_frac(i), where Kc is a preset correction coefficient, a positive value of ΔO indicates an increase in opening degree, and a negative value of ΔO indicates a decrease in opening degree; then, the corrected opening degree ΔO is sent to the first flow controller as a component correction command.

[0147] The internal regulating valve is located in the internal flow channel of the first flow controller and controls the flow rate of the gaseous mixed raw material flowing through the first flow controller by changing its own opening degree.

[0148] In some embodiments, the controller sends a component correction command to a first flow controller, which then drives its internal regulating valve to increase or decrease its opening by a correction value ΔO based on the current opening. For example, if E_frac indicates that heavy components such as catalysts are accumulating, it means that the concentration of key components in the current gaseous feedstock is too high. To maintain a constant absolute molar supply, the controller generates a component correction command (with a negative correction value ΔO) to reduce the total output flux, and the internal regulating valve correspondingly reduces its opening. The reduction in the opening of the internal regulating valve directly reduces the flow cross-sectional area of ​​the gaseous feedstock, thereby achieving a downward adjustment of the total output flux.

[0149] Enrichment error refers to the deviation of the actual number of moles of the key component entering the high-temperature reactor per unit time from the absolute molar supply determined based on the preset molar ratio, caused by component fractionation effects. The aforementioned operation of adjusting the total output flux of the gaseous mixed feedstock is precisely to compensate for this enrichment error. This compensation does not change the opening state of the first electrically controlled valve, but only changes the total output flux of the gaseous mixed feedstock by continuously fine-tuning the first flow controller, thereby suppressing the impact of the relative enrichment of the key component in the later stage caused by component fractionation effects on the reaction stability.

[0150] The embodiments in this specification evaluate the fractionation enrichment degree by jointly assessing the temperature and pressure deviation and system running time, and further introduce cumulative mass loss for weighted correction. This enables precise and timely closed-loop compensation for component drift during continuous output, effectively suppressing the ratio deviation caused by the enrichment of heavy components in the later stage, thereby significantly improving the stability of the composition of gaseous mixed raw materials fed into the high-temperature reactor and ensuring the consistency and quality of carbon nanotube products.

[0151] After resolving the control issues at the raw material mixing end, another key challenge lies in preventing the overheated and vaporized gaseous raw material from condensing due to encountering "cold walls" in the delivery pipeline. To address this, the sensing and monitoring array of the carbon nanotube synthesis device also includes a second electrically controlled valve, a second heating module, and a heat flow sensor, with the controller configured to execute a pipeline preheating strategy.

[0152] In some embodiments, such as Figure 1 As shown, the sensing and monitoring array also includes: a second electrically controlled valve 9 disposed at the outlet of the preheating system 2, a second heating module 19 disposed within the preheating system 2, and a heat flow sensor 18 attached to the outer wall of the gas transmission pipeline 4; the controller is further configured to: generate a second drive command to open the second electrically controlled valve before generating a first drive command to open the first electrically controlled valve, so as to allow the heated carrier gas output from the preheating system 2 to flow through the gas transmission pipeline 4; acquire the pipe wall temperature data fed back by the heat flow sensor and calculate the pipe wall heat absorption rate; and generate a first drive command to control the opening of the first electrically controlled valve in response to the pipe wall heat absorption rate being lower than a preset thermal balance threshold.

[0153] If overheated gaseous mixed raw material suddenly enters a cold gas delivery pipeline, it is prone to condensation and precipitation on the pipe wall, forming droplets or coke-like substances, leading to blockage and severely affecting the concentration of gaseous mixed raw material entering the high-temperature reactor 3. To solve this problem, before outputting the gaseous mixed raw material, the gas delivery pipeline 4 is preheated and flushed with heated carrier gas.

[0154] The second electrically controlled valve 9 refers to the controllable opening and closing valve at the outlet of the preheating system 2, used to control whether the heated carrier gas enters the gas delivery pipeline 4. For example, the second electrically controlled valve can be a solenoid valve. The output of the controller is connected to the drive circuit of the second electrically controlled valve to control its opening or closing.

[0155] The second heating module 19 refers to a heating component installed inside the preheating system 2 for providing heat to the carrier gas. For example, the second heating module can be an electric heating wire or a heating rod. The output of the controller is connected to the power controller (such as a solid-state relay) of the second heating module to adjust its heating power.

[0156] The heat flow sensor 18 is a sensor attached to the outer wall of the gas pipeline 4 to sense changes in the pipe wall temperature and reflect the heat absorption process of the pipeline. In some embodiments, the heat flow sensor is attached to the outer wall of the gas pipeline 4 near the gaseous mixed raw material confluence section or a critical cold spot. The input of the controller is connected to the heat flow sensor to form a closed-loop monitoring link for the preheating process of the gas pipeline.

[0157] The second drive command is an opening control signal sent by the controller to the second solenoid valve. It is issued before the first solenoid valve opens and is used to allow the heated carrier gas to flow through the entire gas pipeline 4 before the gaseous mixed raw material. In some embodiments, after confirming that the temperature data inside the container has reached the preset superheat temperature, the controller does not immediately open the first solenoid valve, but instead generates the second drive command to open the second solenoid valve, so that the device can start the pipeline preheating.

[0158] The pipe wall temperature data refers to the temperature value of the outer wall of the gas pipeline 4 output by the heat flux sensor. After the second electrically controlled valve is opened, the controller begins to periodically collect the pipe wall temperature data Tw(i) output by the heat flux sensor, where i represents the sampling time.

[0159] The pipe wall heat absorption rate is a parameter used to characterize the rate of change of the heat absorption state of the gas transmission pipeline 4 during the pipeline preheating process. In some embodiments, the controller reads the pipe wall temperature data Tw(i) at the current moment and the pipe wall temperature data Tw(i-1) at the previous moment, reads the sampling time interval Δt, and calculates the pipe wall temperature rise rate Rw(i) = [Tw(i) - Tw(i-1)] / Δt; then, Rw(i) is smoothed by a window to obtain a stable pipe wall heat absorption rate Rh(i). In the initial stage of pipeline preheating, the gas transmission pipeline 4 is relatively cold, and Rh(i) is usually large; as the gas transmission pipeline gradually heats up and approaches the temperature of the heated carrier gas, Rh(i) gradually decreases.

[0160] The preset heat balance threshold refers to the threshold value at which the gas pipeline 4 transitions from the rapid heat absorption stage to the near-steady-state heat balance stage. When the heat absorption rate of the pipe wall is lower than the preset heat balance threshold, the gas pipeline 4 is considered to have basically completed preheating. In some embodiments, the preset heat balance threshold is a pre-calibrated, near-zero temperature rise rate value, for example, Rth = 0.5℃ / min.

[0161] Furthermore, in order to adapt to different mixed feedstock formulations and operating conditions, the preset heat balance threshold is dynamically adjusted by the controller based on the composition of the mixed feedstock, the current transportation risk, the gasification output pressure, and the ambient temperature, so as to solve the drawbacks of fixed thresholds being unable to adapt to different formulations and outputs.

[0162] Current transport risk refers to the risk level or risk parameter of condensation, segregation, or transport instability of the gaseous mixture during transport. In some embodiments, the current transport risk is obtained by the controller based on the degree of fractionation enrichment; the more severe the fractionation enrichment, the higher the current transport risk.

[0163] The vaporization output pressure refers to the current pressure state parameter corresponding to the upstream of the first solenoid valve or the output side of pressure vessel 1, that is, the pressure data P(i) inside the vessel collected by the first pressure sensor. The higher the vaporization output pressure, the easier it is for the gaseous mixed raw materials to condense, and the higher the requirement for thermal balance.

[0164] Ambient temperature refers to the temperature data of the environment in which the gas pipeline 4 is located, and is used to reflect the heat dissipation conditions of the gas pipeline 4. In some embodiments, the ambient temperature can be collected by an ambient temperature sensor installed in the environment, or a preset ambient temperature parameter can be used when there is no ambient temperature sensor. The lower the ambient temperature, the faster the pipeline dissipates heat, and the higher the requirement for thermal balance.

[0165] In some embodiments, the controller determines a matching heat balance threshold Rth by querying a database based on the composition of the mixed feedstock, the current transport risk, the vaporization output pressure, and the ambient temperature. The database is constructed as follows: during historical experiments or early operation, operating condition data is recorded for each successful opening of the first electrically controlled valve without condensation. Each data point includes the composition of the mixed feedstock, transport risk, vaporization output pressure, ambient temperature, and the actual measured pipe wall heat absorption rate. This measured pipe wall heat absorption rate is used as the heat balance threshold corresponding to that data point and stored in the database along with the other operating condition parameters. During operation, the controller uses the current composition of the mixed feedstock, the current transport risk, the vaporization output pressure, and the ambient temperature as query conditions to match the closest (e.g., shortest vector distance) historical operating condition data in the database and retrieves the corresponding heat balance threshold as the Rth used for current control.

[0166] The embodiments in this specification dynamically link a preset thermal equilibrium threshold with parameters such as the composition of the mixed raw materials, the current transportation risk, and the gasification output pressure. This ensures that under high condensation risk conditions with high catalyst concentration and high pressure, the gas transmission pipeline must reach a strict thermal equilibrium state before gas transmission is allowed. This effectively prevents the instantaneous condensation and precipitation of key components on the pipe wall, achieving a balance between transportation stability and production efficiency.

[0167] In some embodiments, the controller continuously compares the pipe wall heat absorption rate Rh(i) with a preset thermal balance threshold Rth. When Rh(i) ≤ Rth, and this condition is maintained for at least a preset confirmation time, it indicates that the gas pipeline has been sufficiently preheated. At this point, the controller generates a first drive command to open the first electrically controlled valve, allowing the gaseous mixed raw material to be introduced into the preheated gas pipeline, thereby reducing the risk of condensation. If the condition is not met, it indicates that the pipe wall of the gas pipeline is still relatively cold, posing a risk of condensation. The controller will maintain the current state, allowing the heated carrier gas to continue preheating the gas pipeline until Rh(i) ≤ Rth is met, and this condition is maintained for at least a preset confirmation time. The preset confirmation time is manually preset, for example, 5 seconds.

[0168] The embodiments in this specification preheat the gas pipeline with heated carrier gas before outputting the gaseous mixed raw material, and use the heat absorption rate of the pipe wall as the criterion for opening the gaseous mixed raw material output. This can significantly reduce the risk of condensation and blockage caused by cold pipe walls and improve the stability and continuity of gaseous mixed raw material transportation.

[0169] To ensure the efficiency and safety of pipeline preheating, the controller is also equipped with a closed-loop adaptive matching function for carrier gas temperature, namely temperature difference adaptive matching operation, before performing pipeline preheating operation.

[0170] In some embodiments, the controller is further configured to: determine the target preheating temperature of the carrier gas based on the temperature data inside the container and a preset thermal redundancy deviation value; adjust the drive duty cycle of the second heating module through a proportional-integral-differential algorithm so that the carrier gas temperature data fed back by the second temperature sensor is equal to the target preheating temperature; and generate a second drive command to open the second electrically controlled valve in response to the carrier gas temperature data being equal to the target preheating temperature, so as to allow the heated carrier gas output by the preheating system 2 to flow through the gas delivery pipe 4, thereby ensuring that the temperature difference between the heated carrier gas and the gaseous mixed raw material is within a preset temperature difference tolerance when they converge.

[0171] The confluence point refers to the location in the gas pipeline 4 where the gaseous mixed raw material from the pressure vessel 1 and the heated carrier gas from the preheating system 2 meet and mix.

[0172] The thermal redundancy deviation value refers to the preset temperature increment value used to compensate for heat transfer losses of the carrier gas between the outlet of preheating system 2 and the confluence point. If the target preheating temperature of the carrier gas is set to a fixed value, it will not be able to adapt to changes in the temperature of the gaseous mixture, and an excessive temperature difference between the two will also cause thermal shock or condensation at the confluence. This embodiment uses a temperature difference adaptive matching operation to allow the carrier gas temperature to follow the temperature of the gaseous mixture. The thermal redundancy deviation value can be a positive temperature increment set manually based on experience, such as +15°C, to ensure that the carrier gas temperature is always slightly higher than the temperature of the gaseous mixture.

[0173] The target preheating temperature refers to the target temperature of the carrier gas preset in the pipeline, which serves as the control target for the second heating module. In some embodiments, the target preheating temperature is calculated from the temperature data inside the container and the thermal redundancy deviation value. For example, the target preheating temperature T_tar = T(i) + ΔTr, where ΔTr is the thermal redundancy deviation value.

[0174] The carrier gas temperature data refers to the actual temperature value Tg(i) of the carrier gas at the outlet of the preheating system 2, fed back by the second temperature sensor. In some embodiments, the controller reads the carrier gas temperature data uploaded by the second temperature sensor in real time for PID closed-loop control.

[0175] The Proportional-Integral-Derivative (PID) algorithm is a closed-loop control algorithm that calculates the temperature deviation using proportional, integral, and derivative terms and outputs the control quantity.

[0176] In some embodiments, the controller calculates the temperature deviation e(i) = T_tar - Tg(i) between the target preheating temperature T_tar and the carrier gas temperature data Tg(i) fed back by the second temperature sensor, and then calculates the control quantity U(i) through a linear combination of the proportional, integral and derivative terms: U(i) = Kp·e(i) + Ki·Σe(i)·Δt + Kd·[e(i) - e(i-1)] / Δt, where Kp, Ki and Kd are the preset proportional coefficient, integral coefficient and derivative coefficient, respectively.

[0177] The drive duty cycle refers to the drive parameter that controls the on / off time ratio of the second heating module, and is used to adjust the average heating power of the second heating module.

[0178] In some embodiments, the controller uses a normalized linear mapping method to convert the control quantity U(i) into the drive duty cycle D(i) of the second heating module. For example, D(i) = (U(i) / U_max) × 100%, where U_max is the maximum output value of the control quantity, a preset parameter corresponding to a 100% drive duty cycle. When the calculated result exceeds the range of 0% to 100%, the controller performs amplitude limiting to ensure that D(i) is within the range of 0% to 100%. The second heating module operates according to this drive duty cycle. The controller continuously adjusts the drive duty cycle through a PID algorithm, forming a closed loop, ultimately making the carrier gas temperature data Tg(i) precisely equal to the dynamically changing target preheating temperature T_tar.

[0179] When |e(i)| remains within the PID tolerance range and maintains a preset stabilization time, the controller determines that the carrier gas temperature data equals the target preheating temperature, meaning the carrier gas preheating is ready. The PID tolerance range refers to the allowable temperature deviation range in PID control. Its value can be preset manually, usually set to a small value (e.g., ±1℃) to ensure that the carrier gas temperature accurately tracks the target preheating temperature. The preset stabilization time can also be preset manually, for example, 3 seconds. At this point, the controller generates the aforementioned second drive command, opening the second electronically controlled valve to allow the heated carrier gas to enter the gas delivery pipeline 4 for pipeline preheating, thereby ensuring that the temperature difference between the heated carrier gas and the gaseous mixed raw material is within the preset temperature difference tolerance when they converge.

[0180] The preset temperature difference tolerance refers to the maximum permissible temperature difference range between the heated carrier gas and the gaseous mixture when they merge. When the temperature difference between the heated carrier gas and the gaseous mixture is within the preset temperature difference tolerance, the gaseous mixture will not cool down and condense due to a significant temperature difference. In some embodiments, the preset temperature difference tolerance can be manually preset based on experience; for example, the preset temperature difference tolerance can be ±5°C.

[0181] If the carrier gas temperature data is not equal to the target preheating temperature, the controller will continuously adjust the drive duty cycle of the second heating module through the PID algorithm until the carrier gas temperature data equals the target preheating temperature.

[0182] The embodiments in this specification adaptively set the target preheating temperature of the carrier gas based on the temperature data inside the container, and use PID closed-loop control of the second heating module. This allows the carrier gas temperature to more accurately match the temperature of the gaseous mixed raw materials, reducing condensation and thermal shock caused by temperature differences at the junction, thereby further improving the stability of the transport and the consistency of the continuous reaction.

[0183] Figure 6 This is a partial structural schematic diagram of a carbon nanotube synthesis apparatus according to some embodiments of this specification. Figure 11 This is a schematic diagram of the radial cross-section of a gas transmission pipeline according to some embodiments of this specification.

[0184] In some embodiments, such as Figure 6 As shown, the actuation drive unit includes a pneumatic control system 40. (As indicated...) Figure 11 As shown, the gas pipeline 4 adopts a coaxial double-layer nested structure, including an inner porous metal pipe 51, an outer dense heat tracing pipe 52, and a sealed annular interlayer 53 located between the porous metal pipe 51 and the dense heat tracing pipe 52; the gas circuit control system 40 is configured to continuously pump inert gas into the sealed annular interlayer 53 after heating it, so that the heat tracing gas permeates through the porous metal pipe 51 and flows inward, thereby forming a gas film boundary layer 54 on the inner wall surface of the porous metal pipe 51.

[0185] In some embodiments, such as Figure 6 As shown, the gaseous mixed raw material output from pressure vessel 1 and the heated carrier gas output from preheating system 2 are transported to high-temperature reactor 3 through gas pipeline 4, where a catalytic pyrolysis reaction occurs to generate carbon nanotubes.

[0186] In some embodiments, such as Figure 11 As shown, the gas transmission pipeline 4 adopts a coaxial double-layer nested structure, including an inner porous metal pipe 51, an outer dense heat tracing pipe 52, and a sealing annular interlayer 53 located between the porous metal pipe 51 and the dense heat tracing pipe 52.

[0187] The coaxial double-layer nested structure is a pipeline topology consisting of two tubular physical components with a common central axis. The coaxial double-layer nested structure is formed by placing a porous metal tube 51 inside a dense heat tracing tube 52, ensuring that the central axes of the two tubes coincide. The two ends of the tubes are sealed by welding.

[0188] The porous metal tube 51 is a metal pipe with a microporous structure in its wall that allows gas to pass through, serving as the main channel for transporting mixed gases. The porous metal tube 51 can be manufactured using processes such as powder metallurgy sintering or multi-layer metal wire mesh sintering. Its wall has uniformly distributed nano- or micro-sized pores, allowing gas molecules to pass through under pressure difference, but it has a blocking effect on liquids or large molecular particles.

[0189] The dense heat tracing pipe 52 is a pipe wrapped around the outside of the porous metal pipe 51, with no pores in the pipe wall, serving as an outer protective shell and heat tracing cavity. The dense heat tracing pipe 52 is made of dense metal materials such as stainless steel, and the space formed between its inner wall and the outer wall of the porous metal pipe 51 is the sealing annular interlayer 53.

[0190] The sealed annular interlayer 53 is a closed space formed between the outer wall of the porous metal tube 51 and the inner wall of the dense heat tracing tube 52. Gas inside the sealed annular interlayer 53 cannot escape through the dense heat tracing tube 52, but can only permeate into the porous metal tube 51 through the pores of the porous metal tube 51.

[0191] The gas path control system 40 is a control module comprising a pump body, valves, sensors, and a microprocessor, used to adjust the supply parameters and flow direction of the heating gas. In some embodiments, it is combined with... Figure 6 and Figure 11 As shown, the gas path control system 40 is configured to continuously pump an inert gas into the sealed annular jacket 53 after heating it, so that the heated gas can permeate inward through the porous metal pipe 51, thereby forming a gas film boundary layer 54 on the inner wall surface of the porous metal pipe 51.

[0192] Inert gases are chemically stable gases that do not react with the mixed raw materials or carbon nanotubes. Examples include argon or nitrogen.

[0193] Heat tracing gas is a high-temperature inert gas used to provide heat and act as a gas barrier. Heat tracing gas is essentially a heated inert gas, such as argon or nitrogen heated to 300°C to 600°C.

[0194] In some embodiments, the gas path control system 40 continuously pumps the heating gas into the sealed annular jacket 53. The gas pressure inside the sealed annular jacket 53 is greater than the pressure of the mixed gas inside the porous metal tube 51, forming a radial pressure difference. Driven by the radial pressure difference, the heating gas passes through the micropores of the porous metal tube 51, precipitates on the inner wall of the porous metal tube 51, and covers the inner wall surface, forming a gas film boundary layer 54. For an explanation of how the gas path control system 40 continuously pumps the heating gas into the sealed annular jacket 53, please refer to the relevant description below.

[0195] The gas film boundary layer 54 is a thin film of gas formed on the inner wall surface of the porous metal pipe 51 after the heated gas permeates inward through the porous metal pipe 51. This gas film boundary layer acts as a physical barrier, preventing condensable components such as carbon sources in the mixed gas from directly contacting the inner wall surface of the porous metal pipe 51. This avoids condensation caused by the pipe wall temperature being lower than the dew point of the mixed gas, and also avoids carbon buildup and coking caused by excessively high pipe wall temperatures. At the same time, it also weakens the catalytic decomposition effect of the high-temperature metal wall on the reactants to a certain extent, ensuring stable delivery of the mixed raw materials.

[0196] This specification describes an embodiment that constructs a coaxial double-layer nested gas delivery pipeline with a sealed annular interlayer. Inert gas is actively heated and continuously pumped into the sealed annular interlayer as a heat-tracing gas. This allows the heat-tracing gas to permeate through a porous metal pipe and form a gas film boundary layer on the inner wall surface of the porous metal pipe. This achieves non-contact physical isolation and dynamic thermal compensation of the mixed gas, effectively solving the technical problem of easy condensation and carbon buildup in the gas delivery pipeline during continuous carbon nanotube production. It also significantly improves the stability of the mixed gas supply and the long-term operational reliability of the device.

[0197] In some embodiments, such as Figure 6 As shown, the gas circuit control system 40 includes a gas density meter 41 located at the inlet of the gas pipeline 4, and an electro-hydraulic pressure regulating valve 42 and a gas heater 43 located on the inert gas pumping pipeline.

[0198] Gas density meter 41 is a detection instrument used to measure the average fluid density of the mixed gas in the gas transmission pipeline 4 in real time, such as a Coriolis mass flow density meter or a vibrating cylinder density meter. Gas density meter 41 is installed at the inlet of gas transmission pipeline 4, that is, the section of the pipe after the gaseous mixed raw material and the heated carrier gas merge and before entering the porous metal pipe, and is used for feedforward sensing of the concentration change of the mixed gas entering the gas transmission pipeline.

[0199] The inert gas pumping line is a fluid passage connecting the inert gas source 601 and the sealed annular jacket. The inlet end of the pumping line is connected to the inert gas source 601, and the outlet end is connected to the opening on the dense heat tracing pipe. An electro-hydraulic pressure regulating valve 42 and a gas heater 43 are also installed on the pumping line.

[0200] The electro-hydraulic pressure regulating valve 42 is a regulating valve that controls the fluid pressure through an electrical signal, used to regulate the pressure of the inert gas entering the sealed annular jacket.

[0201] Gas heater 43 is a device for rapidly heating inert gas, such as an electric heating belt or a coil-type gas heater. Gas heater 43 is located after electro-hydraulic pressure regulating valve 42 and is used to control the temperature of pressurized inert gas to obtain a heated gas.

[0202] like Figure 6 As shown, an inert gas source provides inert gas. The inlet end of the inert gas pumping pipeline is connected to the inert gas source 601. The inert gas is delivered to the electro-hydraulic pressure regulating valve 42 through the pumping pipeline. The pressurized inert gas obtained by the electro-hydraulic pressure regulating valve 42 is delivered to the gas heater 43 through the pumping pipeline. The pressurized and heated inert gas obtained by the gas heater 43 is the heat tracing gas. The heat tracing gas is delivered to the gas transmission pipeline 4 through the pumping pipeline. The outlet end of the pumping pipeline is connected to the opening on the dense heat tracing pipe so that the heat tracing gas can enter the sealed annular jacket.

[0203] In some embodiments, the pneumatic control system is further configured to perform Figure 7 The process shown in step 700 is to obtain the heated gas.

[0204] Figure 7 This is an exemplary flowchart illustrating the generation of heat-tracing gas according to some embodiments of this specification. Figure 7 As shown, process 700 includes steps 710-770.

[0205] Step 710: Obtain the average fluid density of the mixed gas transported in the gas pipeline using a gas density meter.

[0206] Average fluid density refers to the average density of the mixed gas after detection by a gas density meter and filtering. In some embodiments, the gas path control system receives multiple continuous detection signals (i.e., multiple continuously acquired densities of the mixed gas) output by the gas density meter and performs moving average or low-pass filtering on the multiple continuous detection signals to obtain the average fluid density. For details regarding the mixed gas, please refer to [link / reference]. Figure 6 Related descriptions.

[0207] Step 720: In response to the average fluid density being greater than a preset density threshold, the current fluid pressure and current fluid temperature of the mixed gas are obtained.

[0208] A preset density threshold is a critical density constant used to characterize the risk of wall condensation or carbon buildup when the concentration of a gas mixture rises to a level that may trigger such an increase. The preset density threshold can be manually calibrated based on historical data.

[0209] When the average fluid density exceeds a preset density threshold, it indicates a significant increase in the concentration of condensable components such as carbon sources entering the gas pipeline. The current supply parameters of the heating gas (such as current pump pressure and current temperature) may be insufficient to maintain a stable gas film boundary layer, posing a high risk of condensation. In this situation, the gas path control system must proactively increase the supply capacity of the heating gas to cope with the operating conditions. In response, the gas path control system immediately reads the pressure and temperature sensors installed within the gas pipeline to obtain the current fluid pressure and temperature of the mixed gas.

[0210] If the average fluid density is not greater than the preset density threshold, it means that the concentration of the mixed gas is within the normal range. The gas circuit control system can maintain the current gas supply parameters of the heating gas unchanged and continue monitoring.

[0211] Current fluid pressure refers to the real-time pressure value of the gas mixture at the current moment, which is collected by a pressure sensor installed inside the gas transmission pipeline. Current fluid temperature refers to the real-time temperature value of the gas mixture at the current moment, which is collected by a temperature sensor installed inside the gas transmission pipeline.

[0212] Step 730: Determine the target pump inlet pressure based on the average fluid density, current fluid pressure, and current fluid temperature.

[0213] The target pump-in pressure refers to the pressure setting required for the heating gas to enter the sealed annular interlayer. The target pump-in pressure determines the stiffness and radial penetration resistance of the gas film boundary layer. A higher target pump-in pressure results in a greater radial momentum flux of the heating gas flowing inward, leading to a denser gas film boundary layer and stronger resistance to condensation penetration. However, an excessively high target pump-in pressure may cause excessive consumption of the heating gas or damage to the micropores of the porous metal tube; therefore, a suitable target pump-in pressure needs to be determined based on the actual operating conditions.

[0214] In some embodiments, the gas path control system can determine the target pump inlet pressure based on average fluid density, current fluid pressure, and current fluid temperature in various ways. For example, the gas path control system internally stores a pre-calibrated pressure regulation mapping table. This pressure regulation mapping table is a multi-dimensional array that takes average fluid density, current fluid pressure, and current fluid temperature as input query parameters, and can directly output the target pump inlet pressure by looking up the table. The higher the average fluid density, the higher the current fluid pressure, and the lower the current fluid temperature, the higher the output target pump inlet pressure.

[0215] In some embodiments, the gas path control system is further configured to: output radial diffusion pressure based on the average fluid density, current fluid pressure, and current fluid temperature using a dew point prediction model, the dew point prediction model being constructed based on the molecular weight of each component of the mixed gas and the vapor pressure equation parameters of each component; and determine the target pumping pressure based on the current fluid pressure, radial diffusion pressure, and a preset pressure margin. (For more information on this section, please refer to...) Figure 9 Related explanations.

[0216] Step 740: Determine the target opening degree of the electro-hydraulic pressure regulating valve based on the target pump inlet pressure.

[0217] The target opening degree refers to the degree to which the valve core of the electro-hydraulic pressure regulating valve is open. The target opening degree can be expressed as a percentage, with 0% representing fully closed and 100% representing fully open.

[0218] In some embodiments, the pneumatic control system internally stores the pressure-opening characteristic curve of the electro-hydraulic pressure regulating valve. The target pump inlet pressure is substituted into this pressure-opening characteristic curve for interpolation calculation to obtain the corresponding target opening. The pressure-opening characteristic curve can be determined experimentally during factory calibration or on-site commissioning, reflecting the correspondence between the valve opening and output pressure of the electro-hydraulic pressure regulating valve; the higher the pump inlet pressure, the larger the corresponding valve opening.

[0219] Step 750: Control the electro-hydraulic pressure regulating valve to open to the target opening degree so that the pumping pressure of the inert gas reaches the target pumping pressure.

[0220] In some embodiments, the gas path control system generates a pulse width modulated drive current corresponding to the target opening degree and sends this pulse width modulated drive current to the solenoid coil of the electro-hydraulic pressure regulating valve. The solenoid coil drives the valve core to move to the position corresponding to the target opening degree, thereby adjusting the flow cross-sectional area so that the pumping pressure of the inert gas reaches the target pumping pressure.

[0221] Step 760: Determine the target temperature based on the average fluid density, current fluid pressure, and type of carbon source.

[0222] The type of carbon source refers to the type of carbon source substance used, such as methane, ethylene, ethanol, toluene, xylene, etc. The type of carbon source is manually set and transmitted to the gas path control system.

[0223] The target temperature is the setpoint temperature that the gas heater outputs for the tracing gas. Heating the inert gas to the target temperature aims to create a dynamic thermal barrier on the inner wall of the porous metal tube, ensuring that the mixed gas remains within a safe temperature window. The safe temperature window refers to the temperature range within which the mixed gas neither condenses nor prematurely pyrolyzes. Its lower limit is the dew point temperature of the mixed gas (the temperature at which the gaseous carbon source in the mixed gas begins to liquefy and precipitate droplets), and its upper limit is the pyrolysis critical temperature of the carbon source (the temperature at which the gaseous carbon source begins to break chemical bonds and undergo thermal decomposition). Setting the target temperature within this safe temperature window prevents the carbon source from precipitating droplets due to temperature decreases and also avoids premature pyrolysis of the carbon source due to localized overheating.

[0224] In some embodiments, the gas path control system internally stores phase transition surface data corresponding to different carbon source types. Phase transition surface data is a set of critical temperatures used to describe the phase transition (condensation or pyrolysis) of the mixed gas under different density and pressure conditions. The gas path control system can retrieve the corresponding phase transition surface data based on the type of carbon source.

[0225] The phase transition surface data includes two surfaces: Surface A is the dew point temperature surface, with the X-axis representing the average fluid density, the Y-axis representing the current fluid pressure, and the Z-axis representing the dew point temperature of the mixed gas; Surface B is the pyrolysis critical temperature surface, with the X-axis representing the average fluid density, the Y-axis representing the current fluid pressure, and the Z-axis representing the pyrolysis critical temperature of the carbon source. The gas path control system uses the acquired average fluid density and current fluid pressure as input coordinates (X, Y), performs bilinear interpolation on surfaces A and B respectively, searches for and calculates the corresponding dew point temperature and pyrolysis critical temperature; then, the average of the two is taken as the phase transition critical temperature, and a preset safety temperature difference constant (e.g., +15℃) is added to this phase transition critical temperature to obtain the target temperature.

[0226] Step 770: Control the gas heater to heat the pressurized inert gas to the target temperature to obtain the heat-tracing gas.

[0227] In some embodiments, the gas path control system generates a power control signal based on the target temperature and sends it to the gas heater. The gas heater increases or decreases its operating power according to the power control signal to heat the pressurized inert gas, and uses a built-in temperature sensor for closed-loop feedback to maintain the temperature at the target level, thus obtaining the heat-tracing gas. At this point, the precisely pressurized and temperature-controlled inert gas is the qualified heat-tracing gas, which is continuously pumped into the sealed annular interlayer to maintain the stability of the gas film boundary layer.

[0228] This specification's embodiments introduce average fluid density as a feedforward parameter, enabling the gas path control system to adaptively increase the pressure and temperature of the heating gas under conditions of increased mixed gas concentration. This control strategy avoids blind energy consumption during low-load operation while ensuring the stiffness of the gas film boundary layer and the stability of the temperature field at high loads, achieving dual protection against condensation and pyrolysis, as well as energy efficiency optimization.

[0229] Although a basic gas film boundary layer can be formed by pumping in heated gas using uniform gas supply parameters, a significant axial temperature gradient exists at both ends of the gas pipeline during continuous production. The inlet end of the gas pipeline connects to the junction of the gaseous mixed raw material and the heated carrier gas, while the outlet end connects to the inlet end of the high-temperature reactor. Using a single gas supply pressure and temperature makes it difficult to simultaneously meet the different needs of upstream anti-condensation, mid-stage thermal insulation, and downstream efficient preheating. To address this issue, the gas pipeline is functionally segmented axially and differentiated parameter control is implemented.

[0230] Figure 8 This is a cross-sectional structural diagram of an axially segmented gas pipeline according to other embodiments of this specification.

[0231] In some embodiments, such as Figure 8As shown, the dense heat tracing pipe 52 includes a buffer section 521, a shielding section 522, and an excitation section 523. The buffer section 521, the shielding section 522, and the excitation section 523 are connected in pairs via heat-insulating flanges 55. The gas path control system is further configured to: pump heat tracing gas at a first temperature T1 into the sealed annular interlayer of the buffer section 521 at a first pressure P1; pump heat tracing gas at a second temperature T2 into the sealed annular interlayer of the shielding section 522 at a second pressure P2; wherein the second temperature T2 is lower than the first temperature T1, and the second pressure P2 is greater than the first pressure P1, to form a pneumatic insulation layer; and pump heat tracing gas at a third temperature T3 into the sealed annular interlayer of the excitation section 523, so that the heat tracing gas passes through the porous metal pipe 51 to heat the mixed gas inside the porous metal pipe 51, wherein the third temperature T3 is greater than the inlet temperature of the high-temperature reactor.

[0232] Buffer section 521 is the first functional pipe section near the inlet of the gas pipeline, with its internal porous metal pipes remaining continuously connected. Buffer section 521 can provide a temperature and pressure buffer transition zone for the mixed gas that has just entered the gas pipeline, and uses heated gas at the first temperature and first pressure to consolidate the initial gas film boundary layer.

[0233] The shielding section 522 is an intermediate pipe section located between the buffer section 521 and the excitation section 523. The shielding section 522 is used to form a barrier to block heat conduction, blocking the axial heat transfer from the excitation section 523 to the buffer section 521.

[0234] The activation section 523 is the last functional pipe section near the outlet of the gas pipeline, i.e., near the inlet of the high-temperature reactor. The activation section provides a final, efficient, and rapid heating of the mixed gas before it enters the high-temperature reactor, ensuring a uniform temperature distribution and reaching above the reactor's inlet temperature. The reactor's inlet temperature is the lower limit of the temperature that the mixed raw materials must reach before entering the reactor, and it is preset by the process engineers.

[0235] The heat insulation flange 55 is a connector made of a low thermal conductivity material (such as ceramic or asbestos composite material) that is clamped at the connection of each section of the gas transmission pipeline. It is used to block axial solid heat conduction between the buffer section 521, the shield section 522 and the excitation section 523, so as to ensure that the temperature and pressure control of each section does not interfere with each other.

[0236] The first pressure P1 is the input pressure of the heated gas pumped into the sealed annular jacket of the buffer section 521. The first temperature T1 is the input temperature of the heated gas pumped into the buffer section 521. The first temperature T1 provides basic insulation for the mixed gas, preventing the carbon source from condensing and precipitating due to excessively low temperature; the first pressure P1 provides a stable radial pressure difference for the buffer section 521, maintaining the structural integrity of the gas film boundary layer.

[0237] In some embodiments, the gas path control system is further configured to: determine a first temperature and a first pressure every first preset period based on the average fluid density, the current fluid pressure, the current fluid temperature, and the type of carbon source.

[0238] The first preset cycle is the time interval for dynamically adjusting the first temperature and the first pressure, for example, 2 seconds. Setting a shorter first preset cycle is to achieve dynamic adjustment of the first temperature and the first pressure to adapt to real-time disturbances caused by material feeding or pressure fluctuations during the production process.

[0239] In some embodiments, every first preset cycle, the gas path control system acquires the current average fluid density, current fluid pressure, current fluid temperature, and carbon source type. Then, based on... Figure 7 The method described in steps 730 and 750 substitutes the above parameters into the calculation to obtain new target temperature and target pump inlet pressure, which are respectively used as the first temperature and the first pressure. Through periodic calculation, the first temperature and the first pressure follow the real-time operating conditions, providing basic protection for the inlet section (i.e., the buffer section) of the gas pipeline that matches the current operating conditions.

[0240] The embodiments described in this specification, through periodic adjustment of the first temperature and the first pressure, can adapt to disturbances caused by feeding or pressure fluctuations during the production process. This adjustment mechanism prevents transient imbalances from damaging the gas film boundary layer of the buffer section, providing a stable fluid environment for the subsequent shielding and excitation sections.

[0241] The second pressure P2 is the input pressure of the heating gas pumped into the shielded section 522. The second temperature T2 is the input temperature of the heating gas pumped into the shielded section 522.

[0242] In some embodiments, the second temperature T2 is lower than the first temperature T1, and the second pressure P2 is greater than the first pressure P1. This low-pressure, high-temperature configuration, followed by high-pressure, low-temperature configuration, allows the shielding section to forcefully inject the low-temperature heating gas into the sealed annular interlayer at a higher second pressure. A large amount of low-temperature heating gas permeates inward through the porous metal pipe, forming a high-velocity, low-temperature airflow layer on the inner wall surface of the porous metal pipe. This airflow layer is the pneumatic insulation layer. The pneumatic insulation layer is an airflow layer formed by the heating gas within the shielding section to block heat conduction. Utilizing the radial momentum and convection of the high-speed, low-temperature airflow, the pneumatic insulation layer effectively blocks axial heat transfer from the excitation section to the buffer section, protecting the temperature-sensitive carbon source within the buffer section from premature pyrolysis or coking.

[0243] In some embodiments, the gas path control system is further configured to: every second preset period, construct a fluid transfer map based on the physical segmentation of the gas pipeline, the current fluid pressure, the current fluid temperature, the first pressure, the first temperature, the third temperature, and the flow resistance monitoring data; and determine the second pressure and the second temperature based on the fluid transfer map and a fluid transfer model, wherein the fluid transfer model is a machine learning model.

[0244] The second preset cycle is the time interval for dynamically adjusting the second pressure and the second temperature. For example, 5 minutes. Since the optimization of the gas supply parameters of the shielded section requires a comprehensive evaluation based on the relatively stable thermodynamic state and flow resistance characteristics of each section of the gas transmission pipeline, the second preset cycle is longer than the first preset cycle.

[0245] The physical segmentation of a gas pipeline refers to the clearly defined axial division information of the three segments: buffer segment, shielding segment, and excitation segment.

[0246] Flow resistance monitoring data is characteristic data reflecting the magnitude of resistance when a mixed gas flows through a gas transmission pipeline. In some embodiments, pressure sensors are installed at the inlet and outlet ends of the gas transmission pipeline to acquire the inlet and outlet pressures, and the pressure difference between the inlet and outlet pressures is calculated. Simultaneously, the current flow rate of the mixed gas is acquired through a flow meter, and the pressure difference is divided by the current flow rate to calculate the flow resistance monitoring data.

[0247] A fluid transport map is a graphical topology describing the correlation of heat, pressure, and carbon buildup risk between different physical sections of a gas pipeline. In some embodiments, the gas path control system constructs a topology map using a buffer section, a shield section, and an excitation section as nodes v1, v2, and v3, respectively. Current fluid pressure and current fluid temperature are injected as node features into each node. A first temperature and a first pressure are injected into node v1, together with the current fluid pressure and current fluid temperature, to form the node feature vector of node v1. The current fluid pressure and current fluid temperature are together to form the node feature vector of node v2. A third temperature and the high-temperature reactor inlet temperature are injected into node v3, together with the current fluid pressure and current fluid temperature, to form the node feature vector of node v3. The thermal insulation flange between the buffer section and the shield section is used as the edge between node v1 and node v2, and the thermal insulation flange between the shield section and the excitation section is used as the edge between node v2 and node v3. Based on flow resistance monitoring data, the flow resistance difference between adjacent nodes is calculated, and this flow resistance difference and the thermal resistance coefficient of the thermal insulation flange are used as the edge features of the corresponding edges, thus completing the construction of the fluid transport map. For information on current fluid pressure, current fluid temperature, third temperature, and high-temperature reactor inlet temperature, please see [link to documentation]. Figure 7 and Figure 8 Related descriptions.

[0248] A fluid transport model is used to determine the second pressure and the second temperature. In some embodiments, the fluid transport model is a machine learning model, such as a graph neural network (GNN) model. The fluid transport model deduces the second pressure and the second temperature required for the shielding section based on the node features and edge features in the fluid transport graph.

[0249] In some embodiments, the input to the fluid transport model is a fluid transport map, and the output is the node feature vector of node v2, namely the second pressure and the second temperature.

[0250] In some embodiments, the fluid transport model can be obtained based on transport training samples and transport labels. The transport training samples are sample fluid transport maps constructed under multiple historical or simulated operating conditions. The transport labels are the optimal sample second pressure and sample second temperature corresponding to the sample node corresponding to the shielding section in the sample fluid transport map.

[0251] The transfer label is constructed as follows: Different combinations of sample second pressure and sample second temperature are set, and multiple reaction experiments are conducted under the corresponding operating conditions of the sample fluid transfer spectrum. The reaction experiment with the smallest variance in flow resistance monitoring data and the highest quality carbon nanotubes produced by the high-temperature reactor during the reaction experiment period is selected. The sample second pressure and sample second temperature combination set in this reaction experiment serves as the transfer label for this transfer training sample. The highest quality carbon nanotubes can be manually assessed by observing the uniformity of carbon nanotube morphology. Multiple transfer training samples with transfer labels are input into the initial fluid transfer model, and the model parameters are optimized through iterative training to obtain the trained fluid transfer model.

[0252] In some embodiments, a fluid transport map is input into a trained fluid transport model to output a second pressure and a second temperature.

[0253] This specification's embodiments introduce a fluid transfer model, enabling the shielding section control to utilize the segmented topology of the gas pipeline to anticipate the thermal backflow effect of the high temperature in the excitation section on the shielding section and the operational fluctuations in the buffer section. The second pressure determined by the fluid transfer model not only maintains the aerodynamic insulation layer but also dynamically enhances the radial scouring force of the gas film based on the trend of flow resistance monitoring data, precisely balancing the core contradiction between thermal insulation and carbon buildup prevention.

[0254] The third temperature T3 is the input temperature of the heating gas in the excitation section 523. In some embodiments, the third temperature T3 is greater than the inlet temperature of the high-temperature reactor.

[0255] The third temperature, being higher than the inlet temperature of the high-temperature reactor, is to create a sufficient heat transfer temperature difference. This ensures that the tracing gas, after passing through the porous metal tube, can rapidly heat the mixed gas to above the inlet temperature of the high-temperature reactor within the excitation section, allowing it to enter the reaction zone in optimal condition. The third temperature needs to be determined through heat transfer calculations or experimental calibration based on parameters such as the length of the excitation section, the flow rate of the mixed gas, and the wall thickness of the porous metal tube. For example, the third temperature can be 50°C to 150°C higher than the inlet temperature of the high-temperature reactor.

[0256] In practice, the gas path control system uses independent pressure regulating valves and heaters to precisely control the pressure and temperature of the heated gas pumped into the sealed annular interlayer of the buffer section, shielding section and excitation section respectively, so as to achieve the above-mentioned differentiated injection.

[0257] This specification's embodiments construct a functional gradient of buffering, insulation, and activation within the gas transmission pipeline by using axial segmentation of the dense heat tracing pipe and differentiated settings for the first pressure, first temperature, second pressure, second temperature, and third temperature. In particular, the shielding section, through parameter settings where the second temperature is lower than the first temperature and the second pressure is higher than the first pressure, forms an aerodynamic insulation layer, cleverly blocking reverse heat transfer from the activation section to the front buffer section. This prevents premature pyrolysis and coking of the carbon source in the buffer section due to excessively high temperatures, while ensuring that the mixed gas is efficiently and uniformly heated to above the inlet temperature of the high-temperature reactor in the activation section. This fundamentally solves the problem of precise temperature management during long-distance transportation.

[0258] Figure 9 This is a schematic diagram of the process for determining the target pump inlet pressure according to some embodiments of this specification.

[0259] In some embodiments, such as Figure 9 As shown, the gas path control system is further configured to: output radial diffusion pressure 450 based on average fluid density 410, current fluid pressure 420 and current fluid temperature 430 through dew point prediction model 440, which is constructed based on the molecular weight 460 of each component of the mixed gas and the vapor pressure equation parameters 470 of each component; and determine the target pumping pressure 490 based on the current fluid pressure 420, radial diffusion pressure 450 and preset pressure margin 480.

[0260] For information on average fluid density, current fluid pressure, current fluid temperature, gas mixture, and target pump inlet pressure, please refer to [link / reference]. Figure 7 Related descriptions.

[0261] Radial diffusion pressure refers to the minimum pressure required for the heated gas to seep inward from the wall of a porous metal tube to resist the condensation of the mixed gas.

[0262] The dew point prediction model is a computational model based on physicochemical principles deployed within the gas path control system to extrapolate the condensation pressure requirements of the mixed gas. In some embodiments, the inputs to the dew point prediction model 440 are the average fluid density 410, the current fluid pressure 420, and the current fluid temperature 430, and the output is the radial diffusion pressure 450.

[0263] The molecular weight of each component refers to the molar mass of each component in the gas mixture, such as the molar mass of the carbon source (46 g / mol for ethanol). The vapor pressure equation parameters for each component refer to the characteristic coefficients in the Antoine equation, which describes the change of the saturated vapor pressure of each component with temperature. Both the molecular weight and vapor pressure equation parameters for each component can be obtained from chemical engineering handbooks or databases.

[0264] In some embodiments, the dew point prediction model 440 is constructed based on the molecular weight 460 of each component of the mixed gas and the vapor pressure equation parameters 470 of each component. The construction method is as follows: based on the molecular weight of each component and the proportion of each component in the mixed raw material, the average molecular weight of the mixed gas and the mole fraction of the easily condensable component in the mixed gas are calculated. The easily condensable component is typically a carbon source. The actual gas law and the Antoine equation are used as the core calculation equations of the dew point prediction model. The vapor pressure equation parameters of each component are pre-set in the Antoine equation and used to calculate the actual partial pressure and saturated vapor pressure of the easily condensable component, respectively. The difference between the two is the radial diffusion pressure, thereby constructing the dew point prediction model.

[0265] The equation of state for a real gas is: . Z is the actual partial pressure of the easily condensable component, that is, the actual partial pressure exhibited by the easily condensable component; Z is the actual gas compressibility factor, which is a preset constant used to correct the deviation between the actual gas and the ideal gas. The actual gas is a gas mixture, while the ideal gas is a hypothetical gas that conforms to the ideal gas law. The ideal gas law is a theoretical model describing the behavior of an ideal gas. The average fluid density is obtained using a gas density meter. The ideal gas constant is a pre-defined constant used to correlate physical quantities such as temperature and density with pressure. The current fluid temperature is obtained via a temperature sensor; The average molecular weight of the mixed gas is calculated as a weighted average based on the molecular weight of each component and the proportion of each component in the mixed raw material. This represents the mole fraction of the easily condensable component in the mixed gas, calculated based on the ratio of the amounts of each component in the mixed raw material.

[0266] Antoine's equation is: ; This is the saturated vapor pressure of the easily condensable component, i.e., the vapor pressure of the easily condensable component when it reaches vapor-liquid equilibrium at the current fluid temperature; , , The parameters for the vapor pressure equations of each component are indicated by subscripts. Used to index the vapor pressure equation parameters corresponding to different components, when calculating the saturated vapor pressure of easily condensable components. Refers to components that are easily condensable; This represents the current fluid temperature.

[0267] In some embodiments, the process of outputting radial diffusion pressure through a dew point prediction model involves: taking the average fluid density, the current fluid temperature, and the average molecular weight calculated above. mole fraction of easily condensable components Substituting into the real gas law, we obtain the actual partial pressure of the easily condensable component. ; Combine the current fluid temperature with the Antoine equation parameters for the easily condensable component ( , , Substituting into the Antoine equation, we obtain the saturated vapor pressure of the easily condensable component. ; the actual voltage division Subtract saturated vapor pressure This difference is the radial diffusion pressure. , .

[0268] The preset pressure margin is an additional pressure constant set manually to cope with system fluctuations and modeling errors, ensuring safety redundancy in engineering. The preset pressure margin can be manually set based on experience and stored in the gas path control system.

[0269] In some embodiments, after obtaining the radial diffusion pressure, the gas path control system sums the current fluid pressure, the radial diffusion pressure, and a preset pressure margin to calculate the target pump-in pressure: Target pump-in pressure = Current fluid pressure + Radial diffusion pressure + Preset pressure margin. This calculation method ensures that after offsetting the current fluid pressure of the mixed gas, the remaining net pressure difference of the pump-in pressure of the heated gas is sufficient to overcome the osmotic pressure that causes condensation of the mixed gas, and provides an additional safety margin, thereby stably maintaining the gas film boundary layer.

[0270] The embodiments in this specification utilize a dew point prediction model based on physicochemical principles to precisely quantify anti-condensation requirements as radial diffusion pressure. This pressure is then superimposed with the current fluid pressure and a preset pressure margin to achieve accurate setting of the target pump inlet pressure. This method balances theoretical anti-condensation calculations with engineering safety redundancy, resulting in enhanced adaptability to operating conditions and improved control precision.

[0271] Figure 10This is a structural schematic diagram of an interlocking protection system according to some embodiments of this specification.

[0272] After resolving the issues of anti-condensation and thermal management during normal production, the synthesis unit is also equipped with an independent interlocking protection system to ensure absolute safety under abnormal operating conditions.

[0273] In some embodiments, such as Figure 10 As shown, the synthesis apparatus also includes an interlocking protection system 60, which includes a combustible gas detector 61 located outside the gas pipeline 4, a pressure sensor 62 located inside the gas pipeline 4, a venting solenoid valve 63 located at the outlet side of the gas pipeline 4, and a purging solenoid valve 64 located at the inlet side of the gas pipeline 4. The combustible gas detector 61 is configured to acquire the combustible gas concentration; the pressure sensor 62 is configured to acquire pipeline pressure data; the interlocking protection system 60 is configured to: in response to abnormal conditions met by the combustible gas concentration and / or pipeline pressure data: heat the purging gas to a preset temperature range through the heating pipeline 70 located on the purging gas source side; open the venting solenoid valve 63 and the purging solenoid valve 64 to inject the heated purging gas into the porous metal tube to perform purging.

[0274] The interlock protection system 60 is an independent control module for performing safety monitoring and response. It is independent of the gas circuit control system or as a high-priority subsystem of it. It has the highest control authority over the safety actuators to ensure forced intervention in emergency situations.

[0275] Combustible gas detector 61 is a sensor used to monitor the concentration of gases outside the gas pipeline 4, such as a catalytic combustion type or an infrared type. The combustible gas detector is installed near potential leak points such as connecting flanges and valves outside the gas pipeline to obtain the concentration of combustible gases. The concentration of combustible gases is usually expressed as a percentage of the lower explosive limit (LEL), which is the lowest volume percentage concentration of a combustible gas that can explode in air, and can be retrieved from the standard gas database built into the combustible gas detector.

[0276] Combustible gas concentration refers to the real-time concentration value of combustible gas in the external environment of the gas pipeline, which is used to determine whether combustible gas leakage has occurred in the synthesis unit.

[0277] Pressure sensor 62 is a sensor used to monitor the internal pressure of gas pipeline 4 in real time, such as a piezoresistive pressure transmitter. The pressure sensor is installed inside the porous metal pipe to acquire pipeline pressure data.

[0278] Pipeline pressure data refers to the real-time pressure value of the mixed gas inside the gas pipeline, which is used to determine whether the gas pipeline is blocked, leaking, or experiencing pressure runaway.

[0279] The venting solenoid valve 63 is a normally closed safety actuator valve installed on the outlet side of the gas pipeline 4 (near the high-temperature reactor end). It is used to open in an emergency to guide the mixed gas in the gas pipeline to the exhaust gas treatment tower or safety flare and other tail gas treatment systems for venting.

[0280] The purge solenoid valve 64 is a normally closed safety actuator valve installed on the inlet side of the gas pipeline 4 (near the junction of the gaseous mixed raw material and the heated carrier gas). It is used to open in an emergency to quickly inject purge gas into the porous metal tube to perform replacement and purging.

[0281] Abnormal conditions are the criteria for triggering a safety response, including pressure surges and gas anomalies. A pressure surge refers to a pressure change rate (the amount of change in pipeline pressure data over time) calculated by a pressure sensor exceeding a preset safety threshold. A gas anomaly refers to a combustible gas concentration obtained by a combustible gas detector exceeding a preset safe concentration range (e.g., exceeding 25% LEL). Both the safety threshold and the safe concentration range are preset manually based on historical data or experimental calibration.

[0282] When the combustible gas concentration and / or pipeline pressure data meet abnormal conditions, it indicates that the synthesis unit may have experienced a serious leak or internal pressure runaway, posing a high risk of combustion or explosion. In this case, the interlock protection system will shut down the gas circuit control system and switch to purging mode.

[0283] The heating pipe 70 is a pipe section located on the purge gas source side, and its outer wall surface is wrapped with an electric heating element. The purge gas source side refers to the source end where the purge gas is stored or supplied, and is used to provide cold purge gas when the purge mode is started.

[0284] Purge gas is an inert gas, such as high-purity nitrogen or argon, used to displace a gas mixture within a porous metal pipe. The purge gas does not react with any component of the gas mixture and is used to safely remove the gas mixture from the pipeline in emergency situations.

[0285] The preset temperature range is the safe temperature range that the purge gas must reach before purging, such as 300°C to 400°C. The preset temperature range can be manually set based on experience and stored in the interlocking protection system. Its purpose is to prevent cold purge gas from causing thermal stress impact on the high-temperature porous metal pipe wall.

[0286] After the purging mode is activated, the interlocking protection system first controls the heating pipe (located at a safe distance from the gas transmission pipe) to operate at maximum power, heating the flowing purging gas through electric heating elements wrapped around the outer surface of the heating pipe. Simultaneously, closed-loop control is performed based on real-time temperature feedback from thermocouples installed inside the heating pipe, rapidly heating the cold purging gas until its temperature is maintained within a preset range. Subsequently, the interlocking protection system synchronously generates an opening command, driving the venting solenoid valve and the purging solenoid valve to fully open. Since both ends of the gas transmission pipe are opened simultaneously, the heated purging gas flows into the inner cavity of the porous metal pipe at a high flow rate from the inlet side, physically pushing out the residues (including carbon-containing combustible gas mixtures and reaction intermediates) from the outlet side of the porous metal pipe through the venting solenoid valve, discharging them into exhaust gas treatment towers or safety flares or other tail gas treatment systems, completing the rapid and thorough replacement of the combustible gas mixture remaining in the porous metal pipe.

[0287] The embodiments in this specification employ a hot purge displacement operation with a preset temperature range. This rapidly empties the residual mixed gas inside the porous metal tube while avoiding the thermal stress impact caused by the cold purge gas on the high-temperature porous metal tube wall. Thus, in emergency situations, this ensures both the safety of the synthesis unit and the structural lifespan of the gas pipeline.

[0288] In addition to dealing with sudden macroscopic anomalies, the interlocking protection system also has the corresponding monitoring capability for micro-leakage that is difficult to detect with the naked eye.

[0289] In some embodiments, the interlocking protection system is further configured to: acquire the temperature change rate corresponding to the current heating power of the gas heater and the feeding rate of the gas pipeline; call the van der Waals constant and Antoine equation parameters corresponding to the carbon source type; calculate the theoretical pressure change rate based on the temperature change rate, feeding rate, van der Waals constant and Antoine equation parameters, using the differential form of the van der Waals expansion equation; collect the actual pressure change rate in the gas pipeline; calculate the deviation between the actual pressure change rate and the theoretical pressure change rate; and, in response to the deviation satisfying the drift condition, generate a micro-leakage judgment signal and trigger a safe replacement action of the heated gas.

[0290] For information regarding gas heaters, gas pipelines, and heat tracing gases, please see [link / details]. Figure 6 and Figure 7 Related descriptions.

[0291] The current heating power is the actual operating power of the gas heater at the current moment, which can be read directly from the controller built into the gas heater.

[0292] The rate of temperature change refers to the change in temperature of the heated gas over time, caused by the current heating power of the gas heater. In some embodiments, the rate of temperature change corresponding to the current heating power can be obtained by continuously collecting temperature data of the heated gas through a temperature sensor installed at the outlet of the gas heater and performing a first-order difference operation on the collected temperature data.

[0293] The feed rate refers to the amount of mixed raw material input into the gas delivery pipeline per unit time. In some embodiments, the feed rate can be read directly from a flow meter installed at the outlet of the pressure vessel.

[0294] The van der Waals constant is a constant used to correct for intermolecular attraction and volume in real gases. Antoine equation parameters are characteristic parameters used to calculate saturated vapor pressure. In some embodiments, the van der Waals constant and Antoine equation parameters corresponding to different carbon source types can be retrieved from a property parameter database. This database is pre-installed within the interlocking protection system and stores the van der Waals constant and Antoine equation parameters corresponding to different carbon source types; the data is derived from chemical engineering handbooks or experimental calibrations.

[0295] The differential form of the van der Waals expansion equation is a mathematical derivative that reflects the dynamic relationship between pressure and temperature and material quantity. In some embodiments, the interlocking protection system uses the acquired temperature change rate, feeding rate, van der Waals constant, and Antoine equation parameters as input variables, substitutes them into the differential form of the van der Waals expansion equation for floating-point calculation, and obtains the theoretical pressure change rate. The theoretical pressure change rate refers to the theoretically expected rate of pressure change within a gas pipeline.

[0296] Actual pressure change rate This is the actual rate of pressure change within the gas pipeline. In some embodiments, the actual rate of pressure change can be obtained by performing a first-order differential calculation on the real-time readings of the pressure sensors in the interlocking protection system.

[0297] The deviation between the actual pressure change rate and the theoretical pressure change rate can be expressed as the difference between the actual pressure change rate and the theoretical pressure change rate, i.e., the deviation. .

[0298] The drift condition is used to determine whether the deviation continuously exhibits a negative growth trend. For example, an interlocking protection system continuously measures and calculates N deviations, where N is a preset positive integer. If all N consecutive deviations are less than zero (i.e., the actual pressure change rate is always less than the theoretical pressure change rate), and the average absolute value of the N deviations exceeds the inherent measurement noise level of the pressure sensor, then the deviation is determined to meet the drift condition. The inherent measurement noise level of the pressure sensor refers to the random fluctuation amplitude of the output signal of the pressure sensor under stable operating conditions, which can be obtained from the pressure sensor's manufacturer's technical manual.

[0299] If the deviation meets the drift condition, it means that there is a small leak in the gas pipeline, which causes the internal pressure of the gas pipeline to increase less than expected. Therefore, the interlock protection system needs to immediately generate a micro-leakage judgment signal and trigger the safe replacement action of the heating gas.

[0300] The micro-leakage detection signal is a digital signal generated by the interlocking protection system when the detection deviation meets the drift condition. It is used to characterize the presence of a tiny leak in the gas pipeline. After the micro-leakage detection signal is generated, a safety replacement action will be forcibly triggered, that is, the aforementioned interlocking protection process will be triggered: the venting solenoid valve and the purging solenoid valve will be opened, and heated purging gas will be used to replace the gas in the gas pipeline to cut off the source of flammable material at the micro-leakage point and prevent the situation from escalating.

[0301] The embodiments in this specification use the differential form of the van der Waals expansion equation to separate the theoretical pressure change rate caused by temperature changes and material supply under normal operating conditions from the total pressure change. This can accurately identify abnormal phenomena where the actual pressure change rate is consistently lower than the theoretical pressure change rate due to minor leaks, significantly improving the interlocking protection system's early monitoring and proactive defense capabilities against hidden micro-leakage points.

[0302] During emergency venting, directly releasing a high-temperature, high-concentration flammable gas mixture poses a high risk of combustion and explosion. Therefore, the interlocking protection system incorporates further safety features in its venting operation design.

[0303] In some embodiments, such as Figure 10 As shown, the outlet side of the venting solenoid valve 63 is connected to a direct connection pipe 80 for heated gas; when the venting solenoid valve 63 is opened, the interlock protection system 60 is configured to: inject heated gas with a pressure greater than the current fluid pressure of the mixed gas into the direct connection pipe 80 to establish an isobaric hot gas seal 101 in the pressure relief channel 90 located at the outlet of the venting solenoid valve; and control the venting solenoid valve 63 to open in a pulse manner so that the mixed gas in the porous metal pipe released in a single pulse is combined and diluted with the heated gas.

[0304] For information regarding mixed gas, current fluid pressure, and heating gas, please see [link / details]. Figure 6 and Figure 7 Related descriptions.

[0305] The vent outlet side refers to the side of the vent solenoid valve that is not connected to the perforated metal pipe, i.e., the side leading to the waste gas treatment.

[0306] The direct connection pipe 80 is a bypass pipe that connects the heat tracing gas source to the outlet of the relief solenoid valve, and is used to lead the heat tracing gas to the outlet of the relief solenoid valve.

[0307] Just before the venting solenoid valve opens, the interlocking protection system first reads the current fluid pressure in the porous metal pipe, then controls the gas supply valve connected to the direct connection line to fully open, injecting heated gas with a pressure higher than the current fluid pressure into the direct connection line. Because the heated gas pressure is higher, it fills and seals the pressure relief channel on the outlet side of the venting solenoid valve, forming a physical isolation section that completely empties oxygen and creates a positive pressure barrier against the outside air—this is called an isobaric thermal gas seal. The isobaric thermal gas seal ensures that the released combustible mixture is immediately enveloped by inert gas upon leaving the venting solenoid valve, completely isolating it from oxygen.

[0308] After the isobaric thermal gas seal is established, the interlocking protection system outputs periodic opening and closing pulse control signals to the venting solenoid valve (e.g., alternating between 0.5 seconds on and 1 second off). During a single pulse venting, the mixed fluid in the gas pipeline is forced out of the venting solenoid valve and immediately enters the isobaric thermal gas seal established by continuously injected heated gas. The small amount of mixed gas released in a single pulse merges and dilutes with the large amount of heated gas, instantly reducing the mixed gas concentration to below its explosive limit. It is then heated to maintain its gaseous state and safely discharged into subsequent exhaust gas treatment systems such as waste gas treatment towers or safety flares.

[0309] This embodiment of the specification establishes an isobaric thermal gas seal at the outlet of the venting solenoid valve in advance, and, in conjunction with a pulse venting method, cuts and separates the continuously released large volume of combustible gas mixture into smaller streams of combustible gas mixture, which are then combined with a large amount of heated gas for dilution. This operation blocks the contact between oxygen and the combustible gas mixture at the source and reduces the instantaneous concentration of combustible gas released, ensuring the safety of the emergency depressurization process.

[0310] Although the gas film boundary layer reduces condensation and carbon buildup, after prolonged continuous operation, the microporous surface of the porous metal tube may still generate early carbon deposits due to trace amounts of carbon source decomposition or impurity deposition, leading to increased flow resistance. To address this issue without shutting down the plant, this synthesis unit is also equipped with a carbon removal control system.

[0311] In some embodiments, such as Figure 11 As shown, a high-frequency excitation coil 111 is fixed around the gas pipeline 4. The synthesis device also includes a carbon removal control system, which is configured to: determine a target pulse frequency based on the average fluid density in response to flow resistance monitoring data meeting preset coking conditions; and inject a high-frequency pulse current corresponding to the target pulse frequency into the high-frequency excitation coil.

[0312] For information on flow resistance monitoring data and average fluid density, please refer to the relevant descriptions above.

[0313] The high-frequency excitation coil 111 is a coil component made of multiple turns of high-temperature resistant wire, which is coaxially wound and fixed around the dense heat tracing pipe 52 of the gas pipeline 4. After high-frequency alternating current is applied, the high-frequency excitation coil 111 can generate an alternating electromagnetic field that penetrates the wall of the outer dense heat tracing pipe 52 and acts on the inner porous metal pipe 51.

[0314] The carbon removal control system is a control module used to monitor pipeline fouling and control the descaling process. It can be integrated into the gas path control system or used as an independent subsystem.

[0315] The preset coking condition is a criterion for determining when carbon deposits begin to form inside a porous metal tube, leading to an abnormal increase in resistance. In some embodiments, the preset coking condition can be that the flow resistance monitoring data is greater than the flow resistance threshold, which can be preset manually based on historical data or experimental calibration.

[0316] If the flow resistance monitoring data meets the preset coking conditions, it means that tiny solid carbon particles have begun to adhere inside or on the surface of the micropores of the porous metal tube, requiring the triggering of a decarbonization operation.

[0317] The target pulse frequency refers to the alternating current frequency used to excite the porous metal tube to generate mechanical resonance. The mixed gas inside the porous metal tube acts as a damping medium; its average fluid density varies, altering the tube's natural frequency. A higher average fluid density results in a more significant damping effect from the mixed gas, leading to a lower natural frequency for the porous metal tube. Therefore, the target pulse frequency should be adjusted accordingly to ensure optimal excitation.

[0318] In some embodiments, the carbon removal control system has a preset acoustic damping-resonance frequency mapping function. By substituting the average fluid density into this mapping function, the target pulse frequency that enables the porous metal tube to generate the maximum amplitude under the current mixed gas environment can be calculated.

[0319] In some embodiments, the carbon removal control system sends a target pulse frequency to a high-power solid-state inverter generator. The solid-state inverter generator modulates the grid DC power into a high-frequency pulse current with the same frequency as the target pulse frequency, and feeds it directly into a high-frequency excitation coil. The high-frequency pulse current excites an alternating electromagnetic field in the high-frequency excitation coil. This alternating electromagnetic field penetrates the dense heat tracing pipe and acts on the porous metal tube inside. Under the action of the alternating electromagnetic field, the porous metal tube undergoes high-frequency magnetostrictive vibration, causing the attached carbon particles to fatigue and break apart and peel off from the tube wall. The peeled carbon particles are then washed away by the flowing mixed gas, thereby achieving online physical carbon removal and restoring the micropore permeability of the porous metal tube.

[0320] When the flow resistance monitoring data does not meet the preset coking conditions, it means that the porous metal tube is in normal operation. The carbon removal control system remains in standby monitoring and does not inject high-frequency pulse current into the high-frequency excitation coil.

[0321] The embodiments described in this specification utilize real-time capture of flow resistance monitoring data and dynamic adaptive tracking of resonant frequency based on average fluid density. By using a high-frequency electromagnetic field to excite micro-vibrations in the porous metal tube, it is possible to break up and peel off carbon deposits in the early stages of their formation. This not only effectively protects the micropores of the porous metal tube from complete blockage but also extends the maintenance cycle of the synthesis unit without disassembly and cleaning, providing a strong guarantee for long-term continuous and stable production.

[0322] In some embodiments, a carbon nanotube synthesis method is executed by a controller in the aforementioned carbon nanotube synthesis apparatus; the method includes: evaluating the gasification process of the mixed raw materials and / or the transport status of the mixed raw materials in the gas delivery pipeline based on apparatus status data; and, in response to the gasification process and / or transport status meeting preset conditions, controlling the execution drive unit to adjust the apparatus operating parameters to lock the supply amount of components entering the high-temperature reactor and / or ensure the transport stability of the mixed raw materials in the gas delivery pipeline. (See above for more details.) Figures 1-11 Related descriptions.

[0323] In some embodiments, the controller is a core processing module integrating the gas path control system, interlock protection system, and carbon removal control system of the aforementioned carbon nanotube synthesis device. The controller is configured to execute the corresponding functions of the aforementioned gas path control system, interlock protection system, and carbon removal control system. The controller is connected to components such as a gas density meter, electro-hydraulic pressure regulating valve, gas heater, combustible gas detector, pressure sensor, venting solenoid valve, purging solenoid valve, and high-frequency excitation coil to execute the control logic configured in each of the aforementioned systems.

[0324] In some embodiments, the carbon nanotube synthesis method further includes: heating an inert gas and continuously pumping it into a sealed annular interlayer as a heat tracing gas, so that the heat tracing gas permeates inward through the porous metal tube, thereby forming a gas film boundary layer on the inner wall surface of the porous metal tube.

[0325] In some embodiments, the controller may also perform the following operations to generate the heat-tracing gas: obtaining the average fluid density of the mixed gas transported in the gas pipeline using a gas density meter; obtaining the current fluid pressure and current fluid temperature of the mixed gas in response to the average fluid density being greater than a preset density threshold; determining a target temperature based on the average fluid density, current fluid pressure, and carbon source type; controlling the gas heater to heat the inert gas to the target temperature; determining a target pumping pressure based on the average fluid density, current fluid pressure, and current fluid temperature; determining a target opening degree of the electro-hydraulic pressure regulating valve based on the target pumping pressure; and controlling the electro-hydraulic pressure regulating valve to open to the target opening degree so that the pumping pressure of the heated inert gas reaches the target pumping pressure, thereby obtaining the heat-tracing gas.

[0326] In some embodiments, the controller may also perform the following operations to determine the target pump inlet pressure: outputting radial diffusion pressure based on the average fluid density, current fluid pressure, and current fluid temperature using a dew point prediction model; and determining the target pump inlet pressure based on the current fluid pressure, radial diffusion pressure, and a preset pressure margin.

[0327] In some embodiments, the controller may also perform the following interlocking protection operations: acquire combustible gas concentration and pipeline pressure data; in response to abnormal conditions met by the combustible gas concentration and / or pipeline pressure data: heat the purge gas to a preset temperature range through a heating pipeline located on the purge gas source side; open the venting solenoid valve and the purge solenoid valve to inject the heated purge gas into a porous metal tube to perform purging.

[0328] In some embodiments, the controller may also perform the following decarbonization operation: in response to flow resistance monitoring data meeting preset coking conditions, a target pulse frequency is determined based on the average fluid density; a high-frequency pulse current corresponding to the target pulse frequency is injected into the high-frequency excitation coil.

[0329] For details on the specific implementation methods of the above operations, please refer to [link / reference]. Figures 6 to 11 Related descriptions.

[0330] The basic concepts have been described above. Obviously, for those skilled in the art, the detailed disclosure above is merely illustrative and does not constitute a limitation of this specification. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this specification. Such modifications, improvements, and corrections are suggested in this specification and therefore remain within the spirit and scope of the exemplary embodiments described herein.

[0331] Furthermore, unless expressly stated in the claims, the order of processing elements and sequences, the use of numbers and letters, or other names described in this specification are not intended to limit the order of the processes and methods described herein. Although various examples have been discussed in the foregoing disclosure of embodiments that are currently considered useful, it should be understood that such details are for illustrative purposes only, and the appended claims are not limited to the disclosed embodiments; rather, the claims are intended to cover all modifications and equivalent combinations that conform to the substance and scope of the embodiments described herein. For example, while the system components described above can be implemented using hardware devices, they can also be implemented solely using software solutions, such as installing the described system on existing servers or mobile devices.

[0332] Similarly, it should be noted that, in order to simplify the descriptions disclosed herein and thus aid in the understanding of one or more embodiments, the foregoing description of embodiments in this specification sometimes combines multiple features into a single embodiment, drawing, or description thereof. However, this method of disclosure does not imply that the subject matter of this specification requires more features than those mentioned in the claims. In fact, the embodiments contain fewer features than all the features of the single embodiments disclosed above.

[0333] Finally, it should be understood that the embodiments described in this specification are merely illustrative of the principles of the embodiments described herein. Other variations may also fall within the scope of this specification. Therefore, alternative configurations of the embodiments described herein are intended to be illustrative rather than limiting, and should be considered consistent with the teachings of this specification. Accordingly, the embodiments described herein are not limited to those explicitly introduced and described herein.

Claims

1. A carbon nanotube synthesis apparatus, characterized in that, The device includes: Physical synthesis components include a pressure vessel for containing and heating the mixed raw materials, a preheating system for heating the carrier gas, a high-temperature reactor for generating carbon nanotubes, and a gas supply pipeline connecting the pressure vessel, the preheating system, and the high-temperature reactor; the pressure vessel, the preheating system, and the high-temperature reactor are connected through the gas supply pipeline. Sensor monitoring array: used to collect device status data; Execution drive unit: used to adjust the operating parameters of the device; and, Controller: Electrically connected to the sensor monitoring array and the execution drive unit; The controller is configured to: Based on the device status data, assess the gasification process of the mixed feedstock and / or the transport status of the mixed feedstock in the gas pipeline; In response to the gasification process and / or the conveying status meeting preset conditions, the execution drive unit is controlled to adjust the device operating parameters to lock the supply amount of components entering the high-temperature reactor and / or ensure the conveying stability of the mixed raw materials in the gas pipeline.

2. The apparatus according to claim 1, characterized in that, The sensing and monitoring array includes a first temperature sensor and a first pressure sensor disposed inside the pressure vessel, a second temperature sensor disposed at the outlet of the preheating system, and a third temperature sensor disposed inside the high-temperature reactor. The execution drive unit includes a first heating module disposed outside the pressure vessel, a first electrically controlled valve disposed on the gas transmission pipeline and located between the outlet of the pressure vessel and the access point of the preheating system, and a first flow controller disposed on the gas transmission pipeline. The controller is further configured to perform the following operations to control the gasification state and conveying state of the mixed feedstock: Acquire the container internal temperature data fed back by the first temperature sensor and the container internal pressure data fed back by the first pressure sensor; Based on the temperature data and pressure data inside the container, calculate the rate of change of pressure with temperature; In response to the rate of change satisfying a first preset condition, it is determined that the pressure vessel has reached the critical vaporization point. In response to the critical vaporization point being reached inside the pressure vessel, a power adjustment signal is generated and output to drive the first heating module to continue heating until the temperature data inside the vessel reaches a preset superheat temperature, which is higher than the theoretical boiling point of the highest boiling point component in the mixed raw material. After the temperature data inside the container reaches the preset superheat temperature, a first driving command is generated to open the first electrically controlled valve, and the valve opening of the first flow controller is driven based on the preset molar ratio of the components of the mixed raw material. The total output flow of the gaseous mixed raw material is adjusted to lock the absolute molar supply of the key components entering the high-temperature reactor, and the mixed gas formed by the gaseous mixed raw material and the heated carrier gas is sent into the high-temperature reactor.

3. The apparatus according to claim 1, characterized in that, The preheating system has a multi-layered nested folded sleeve structure, the inner core of which is a capillary group; the folded sleeve structure is configured to force the carrier gas to flow repeatedly from the outside to the inside in each layer of pipeline, and to achieve efficient preheating of the carrier gas by increasing the diameter and gradually decreasing the pipe diameter.

4. The apparatus according to claim 2, characterized in that, The pressure vessel is mounted on the weighing module, which is connected to the controller signal to monitor the rate of mass change of the mixed raw material inside the pressure vessel. The controller is further configured to: Based on the temperature data inside the container, the pressure data inside the container, and the rate of mass change, the fractionation enrichment state of the components of the mixed raw material inside the pressure vessel is determined by a fractionation prediction model, wherein the fractionation prediction model is a machine learning model. The heating power of the first heating module is adjusted based on the fractionation enrichment state to compensate for the output concentration fluctuations caused by the difference in volatilization partial pressure of different components and to suppress the component fractionation effect in the pressure vessel.

5. The apparatus according to claim 2, characterized in that, The controller has a pre-stored model of the saturation pressure of the mixed raw materials at different temperatures. The controller is further configured to: During the process of the first electrically controlled valve opening and continuously outputting the gaseous mixed raw material, the theoretical saturation pressure value corresponding to the temperature data inside the container is obtained. The temperature-pressure deviation is determined based on the pressure data inside the container and the theoretical saturation pressure value. Based on the system running time and the temperature and pressure deviation, the degree of fractionation and enrichment of the mixed raw materials in the pressure vessel is determined; Based on the fractionation enrichment level, a component correction command is generated and transmitted to the first flow controller. By fine-tuning the opening of the internal regulating valve of the first flow controller, the total output throughput of the gaseous mixed raw material is adjusted to compensate for the enrichment error of the key components entering the high-temperature reactor.

6. The apparatus according to claim 5, characterized in that, When determining the fractionation enrichment level, the controller is further configured to perform the following operations: Obtain the cumulative mass loss fed back by the weighing module; Based on the cumulative mass loss, the real-time stage characteristics of the gaseous mixed raw material output are determined; The fractionation correction weights corresponding to the real-time stage characteristics are retrieved, and the temperature and pressure deviations are weighted based on the fractionation correction weights to obtain the weighted deviations. The fractionation enrichment degree is determined based on the weighted deviation.

7. The apparatus according to claim 2, characterized in that, The sensing and monitoring array also includes: A second electrically controlled valve is installed at the outlet of the preheating system, a second heating module is installed inside the preheating system, and a heat flow sensor is attached to the outer wall of the gas transmission pipeline; The controller is further configured to: Before generating the first drive command to open the first electrically controlled valve, a second drive command is generated to open the second electrically controlled valve, so as to allow the heated carrier gas output by the preheating system to flow through the gas delivery pipeline; The pipe wall temperature data fed back by the heat flow sensor is obtained, and the pipe wall heat absorption rate is calculated. In response to the pipe wall heat absorption rate being lower than a preset thermal balance threshold, the first drive command is generated to control the opening of the first electrically controlled valve.

8. The apparatus according to claim 7, characterized in that, The preset thermal balance threshold is adjusted by the controller based on the composition of the mixed raw material, the current transport risk, the gasification output pressure, and the ambient temperature.

9. The apparatus according to claim 7, characterized in that, The controller is further configured as follows: Based on the temperature data inside the container and the preset thermal redundancy deviation value, the target preheating temperature of the carrier gas is determined. The drive duty cycle of the second heating module is adjusted by a proportional-integral-differential algorithm so that the carrier gas temperature data fed back by the second temperature sensor is equal to the target preheating temperature. In response to the carrier gas temperature data being equal to the target preheating temperature, a second drive command is generated to open the second electronically controlled valve, allowing the heated carrier gas output by the preheating system to flow through the gas delivery pipeline, thereby ensuring that the temperature difference between the heated carrier gas and the gaseous mixed raw material is within a preset temperature difference tolerance when they converge.

10. The apparatus according to claim 1, characterized in that, The gas transmission pipeline adopts a coaxial double-layer nested structure, including an inner porous metal pipe, an outer dense heat tracing pipe, and a sealing annular interlayer located between the porous metal pipe and the dense heat tracing pipe. The execution drive unit includes a pneumatic control system; The gas path control system is configured to continuously pump an inert gas into the sealed annular interlayer after heating it, so that the heating gas can permeate inward through the porous metal tube, thereby forming a gas film boundary layer on the inner wall surface of the porous metal tube.

11. The apparatus according to claim 10, characterized in that, The gas path control system includes a gas density meter located at the inlet of the gas pipeline, and an electro-hydraulic pressure regulating valve and a gas heater located on the pumping pipeline of the inert gas; the gas path control system is further configured to: The average fluid density of the mixed gas transported in the gas pipeline is obtained by the gas density meter. In response to the average fluid density being greater than a preset density threshold, the current fluid pressure and current fluid temperature of the mixed gas are obtained; The target temperature is determined based on the average fluid density, the current fluid pressure, and the type of carbon source. The gas heater is controlled to heat the inert gas to the target temperature; The target pumping pressure is determined based on the average fluid density, the current fluid pressure, and the current fluid temperature. Based on the target pump inlet pressure, determine the target opening degree of the electro-hydraulic pressure regulating valve; The electro-hydraulic pressure regulating valve is controlled to open to the target opening degree so that the pumping pressure of the heated inert gas reaches the target pumping pressure, thereby obtaining the heat-tracing gas.

12. The apparatus according to claim 11, characterized in that, The dense heat tracing pipe includes a buffer section, a shielding section, and an excitation section, wherein the buffer section, the shielding section, and the excitation section are connected in pairs via heat-insulating flanges; the gas path control system is further configured to: The heat-tracing gas at a first temperature is pumped into the sealed annular interlayer of the buffer section at a first pressure. The heat-tracing gas at a second temperature is pumped into the sealed annular interlayer of the shielding section at a second pressure; wherein the second temperature is lower than the first temperature and the second pressure is greater than the first pressure, to form a pneumatic insulation layer. The heating gas at a third temperature is pumped into the sealed annular interlayer of the excitation section so that the heating gas passes through the porous metal tube to heat the mixed gas inside the porous metal tube. The third temperature is greater than the inlet temperature of the high-temperature reactor.

13. The apparatus according to claim 12, characterized in that, The gas path control system is further configured to: Every first preset period, the first temperature and the first pressure are determined based on the average fluid density, the current fluid pressure, the current fluid temperature, and the type of carbon source.

14. The apparatus according to claim 12, characterized in that, The gas path control system is further configured to: Every second preset period, a fluid transport map is constructed based on the physical segmentation of the gas pipeline, the current fluid pressure, the current fluid temperature, the first pressure, the first temperature, the third temperature, and flow resistance monitoring data. Based on the fluid transport map, the second pressure and the second temperature are determined using a fluid transport model, which is a machine learning model.

15. The apparatus according to claim 11, characterized in that, The gas path control system is further configured to: Based on the average fluid density, the current fluid pressure, and the current fluid temperature, the radial diffusion pressure is output through a dew point prediction model, which is constructed based on the molecular weight of each component of the mixed gas and the vapor pressure equation parameters of each component. The target pumping pressure is determined based on the current fluid pressure, the radial diffusion pressure, and the preset pressure margin.

16. The apparatus according to claim 10, characterized in that, It also includes an interlocking protection system, which includes a combustible gas detector located outside the gas pipeline, a pressure sensor located inside the gas pipeline, a venting solenoid valve located at the outlet side of the gas pipeline, and a purging solenoid valve located at the inlet side of the gas pipeline; the combustible gas detector is configured to acquire combustible gas concentration; the pressure sensor is configured to acquire pipeline pressure data; The interlocking protection system is configured as follows: In response to the combustible gas concentration and / or the pipeline pressure data meeting abnormal conditions: The purge gas is heated to a preset temperature range via a heating pipe located on the purge gas source side. Open the venting solenoid valve and the purging solenoid valve to inject heated purging gas into the porous metal tube to perform purging.

17. The apparatus according to claim 16, characterized in that, The interlocking protection system is further configured as follows: Obtain the temperature change rate corresponding to the current heating power of the gas heater and the feeding rate of the gas pipeline; Call the van der Waals constant and Antoine equation parameters corresponding to the carbon source type; Based on the temperature change rate, the feeding rate, the van der Waals constant, and the Antoine equation parameters, the theoretical pressure change rate is calculated using the differential form of the van der Waals expansion equation. Collect the actual pressure change rate within the gas transmission pipeline; Calculate the deviation between the actual pressure change rate and the theoretical pressure change rate; In response to the deviation satisfying the drift condition, a micro-leakage determination signal is generated and the safe replacement action of the heating gas is triggered.

18. The apparatus according to claim 16, characterized in that, The discharge outlet side of the solenoid valve is connected to a direct pipeline for the heated gas; the interlock protection system is configured to: Injecting a heated gas with a pressure greater than the current fluid pressure of the mixed gas into the direct connection pipeline to establish an isobaric thermal gas seal in the pressure relief channel located at the outlet of the relief solenoid valve; The solenoid valve is controlled to open in a pulse manner so that the mixed gas in the porous metal tube released in a single pulse is combined with and diluted with the heating gas.

19. The apparatus according to claim 10, characterized in that, A high-frequency excitation coil is fixed around the periphery of the gas transmission pipeline; the device also includes a carbon removal control system, which is configured as follows: In response to the flow resistance monitoring data meeting the preset coking conditions, the target pulse frequency is determined based on the average fluid density; A high-frequency pulse current corresponding to the target pulse frequency is injected into the high-frequency excitation coil.

20. A method for synthesizing carbon nanotubes, characterized in that, The method is executed by a controller in a carbon nanotube synthesis apparatus according to claim 1; the method includes: Based on the equipment status data, assess the gasification process of the mixed feedstock and / or the transport status of the mixed feedstock in the gas pipeline; In response to the gasification process and / or the conveying state meeting preset conditions, the control and execution drive unit adjusts the operating parameters of the device to lock the supply amount of components entering the high-temperature reactor and / or ensure the conveying stability of the mixed raw materials in the gas pipeline.

21. A storage medium, characterized in that, The storage medium stores a computer program, which, when executed by a processor, implements the carbon nanotube synthesis method as described in claim 20.

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