A nuclear fusion superconducting coil heat treatment temperature control system and method

Abstract

The present invention discloses a temperature control system and method for the heat treatment of nuclear fusion superconducting coils. The temperature control system includes: a gas heating control subsystem, an electric heating control subsystem, a wind speed control subsystem, a temperature acquisition subsystem, and a temperature analysis and feedback subsystem. The temperature control method includes: performing a temperature control process for electric heating zones during the heat treatment heating phase; and performing a coordinated temperature control process for gas heating and electric heating zones during the heat treatment insulation phase. The present invention significantly reduces peak power load while dynamically allocating the power ratio of gas and electric heating, making it suitable for the heat treatment of nuclear fusion superconducting coils. The actual temperature of each temperature control zone of the heating furnace and superconducting coil is detected in real time and compared with the preset target temperature value of the corresponding process temperature curve. The top layer dynamically adjusts the stirring fan speed to complement the gas-electric power, forming a closed-loop feedback chain from the local to the overall system, effectively improving response speed and stability.

Description

Technical Field

[0001] The present invention relates to the technical field of superconducting coil heat treatment, and in particular to a temperature control system and method for heat treatment of a nuclear fusion superconducting coil. Background Art

[0002] During the manufacturing process for the superconducting coils for nuclear fusion power, due to the unique properties of Nb3Sn material, which is sensitive to stress and strain, the coils will be manufactured using a "winding first, then reaction" technique. This means that after winding, the coils must undergo heat treatment to initiate a solid-state diffusion reaction that forms the A15-type Nb3Sn superconducting phase, thereby generating superconductivity. The formation of the superconducting phase in the Nb3Sn system is highly dependent on the heat treatment process, requiring the superconducting coils to be heat-treated at temperatures of several hundred degrees for dozens of days or more. Current heat treatment methods primarily involve placing the coils in dedicated heat treatment equipment and continuously heating them in a vacuum.

[0003] Temperature uniformity is a key technical indicator for the heat treatment of Nb3Sn superconducting coils. In existing metal forming heat treatment furnaces, the temperature control system of electric-powered heating furnaces uses the coil surface temperature as feedback, controlling the coil temperature through a power controller that controls the power of the heating element. While this system offers high temperature control accuracy, since it relies solely on electricity as the heating source, large superconducting coil heat treatment processes require a very high power reserve and a backup power supply to prevent power failures and loss of heating capacity. Gas-fired heating furnaces, on the other hand, control temperature by adjusting the flow rate of the combustible gas. This involves adjusting the ratio of the fuel gas to the oxidant, or the total flow rate of the mixed gas, based on the power requirements of each stage. However, due to the rapid release of fuel gas power, the power-temperature control accuracy (especially at low temperatures) is low, resulting in poor heat treatment results. Summary of the Invention

[0004] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0005] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a nuclear fusion superconducting coil heat treatment temperature control system and method.

[0006] In order to achieve the above objectives, in a first aspect, the present invention provides a temperature control system for heat treatment of a nuclear fusion superconducting coil, comprising:

[0007] The gas heating control subsystem includes a gas power control module, which is used to control the heating and insulation working parameters of the gas nozzle;

[0008] The electric heating control subsystem includes an electric heating power control module, which is used to control the heating and heat preservation working parameters of the electric heater;

[0009] The wind speed control subsystem includes a fan speed control module, which is used to control the speed operating parameters of the stirring fan;

[0010] A temperature acquisition subsystem, including a thermocouple, which is used to collect temperature parameters of the vacuum crucible and the superconducting coil;

[0011] The temperature analysis feedback subsystem includes a temperature analysis feedback module, which is electrically connected to the gas power control module, the electric heating power control module, the fan speed control module and the thermocouple. The temperature analysis feedback module is used to monitor the temperature of the vacuum crucible and the superconducting coil, analyze the target preset operating parameters and generate a feedback control plan for the heat treatment adjustment process.

[0012] In some embodiments, the superconducting coil is placed inside the vacuum crucible, the inner wall of the vacuum crucible is provided with an electric heater, a heating furnace body is provided outside the vacuum crucible, the inner wall of the heating furnace body is provided with a gas nozzle, a stirring fan is installed on the top of the heating furnace body, and the stirring fan is rotatably connected to the centrifugal impeller through a stirring shaft.

[0013] In some embodiments, the gas nozzle includes a top nozzle, a middle nozzle and a bottom nozzle, dividing the heating furnace body into a top area, a middle area and a bottom area, and the gas nozzles are symmetrically distributed along the longitudinal vertical center section of the heating furnace body. The gas nozzle is connected to a control valve, and the control valve includes a high-temperature electric butterfly valve, an air-fuel ratio valve and a gas solenoid valve. The control valve is electrically connected to the gas power control module.

[0014] In some embodiments, the thermocouple includes a furnace body couple and a workpiece couple, the furnace body couple is arranged on the inner wall of the vacuum crucible, and the furnace body couple is arranged in a circular manner at equal angles along the longitudinal vertical center of the heating furnace body, and the workpiece couple is arranged on the superconducting coil, and the workpiece couple is arranged in a circular manner at equal angles along the longitudinal vertical center of the superconducting coil.

[0015] In a second aspect, the present invention further provides a method for controlling the temperature of a nuclear fusion superconducting coil heat treatment, which is performed by the nuclear fusion superconducting coil heat treatment temperature control system as described in the first aspect. The temperature control method comprises:

[0016] S100, inputting the user's target temperature curve and uniform heating parameter process for heat treatment;

[0017] S200, performing the electric heating zone temperature control process during the low-temperature stage of heat treatment, and real-time detection and judgment on whether to switch to the heating or insulation process;

[0018] S300: Perform the coordinated temperature control process of gas heating and electric heating in the high-temperature stage of heat treatment, and detect and judge in real time whether to switch to the heating or insulation process and the temperature equalization process.

[0019] In some embodiments, the S100 includes:

[0020] S110, importing or inputting a target process temperature curve through an input interface and setting temperature uniformity parameters;

[0021] S120, analyzing the temperature curve and temperature uniformity parameters, and generating a feedback control scheme for the heat treatment adjustment process.

[0022] In some embodiments, the S200 includes:

[0023] S210, self-checking the working status of all temperature-controlled zone thermocouples and reading the first process temperature curve;

[0024] S220: Real-time detection of the temperature values ​​of the heating furnace and superconducting coils fed back by thermocouples in all temperature-controlled zones, and analysis of the current temperature change trend;

[0025] S230, based on the feedback control scheme of the heat treatment adjustment process, converting it into a first target preset operating parameter temperature control instruction sequence, sending a state switching signal control signal to adjust the heating operating parameters of the electric heater;

[0026] S240, the electric heater runs a heating or keeping warm process based on a heating state or keeping warm state switching signal, and the stirring fan runs a temperature equalization process based on a heating state or keeping warm state switching signal.

[0027] In some embodiments, the first target preset operating condition parameter temperature control instruction sequence includes:

[0028] Real-time detection of the actual temperature of each temperature-controlled zone of the heating furnace body and the superconducting coil, and real-time comparison with the preset target temperature value of the first process temperature curve;

[0029] When the difference between the actual temperature change curve and the target temperature of the process curve is greater than the first temperature range, the heating state is automatically switched to the heat preservation state, and the output power working condition parameters of the electric heater of the PID control algorithm are adjusted;

[0030] When the difference between the actual temperature change curve and the target temperature of the process curve is less than the second temperature range, the current heating process continues to run;

[0031] When the absolute value of the difference between the highest or lowest temperature of the superconducting coil and the user's target temperature is less than or equal to the user's required temperature difference, and the absolute value of the difference increases, the stirring fan speed is increased.

[0032] In some embodiments, the S300 includes:

[0033] S310, self-check the working status of all temperature-controlled zone gas nozzles and read the second process temperature curve;

[0034] S320: Real-time detection of the temperature values ​​of the heating furnace and superconducting coils fed back by thermocouples in all temperature-controlled zones, and analysis of the current temperature change trend;

[0035] S330, based on the feedback control scheme for the heat treatment adjustment process, converting the sequence of temperature control instructions to the second target preset operating parameters, and sending a state switching signal control signal to adjust the heating operating parameters of the electric heater, the gas nozzle, and the stirring fan;

[0036] S340, the electric heater and the gas nozzle run a heating or keeping warm process based on the heating state or keeping warm state switching signal, and the stirring fan runs a temperature equalization process based on the temperature.

[0037] In some embodiments, the second target preset operating condition parameter temperature control instruction sequence includes:

[0038] Real-time detection of the actual temperature of each temperature-controlled zone of the heating furnace body and superconducting coil, and real-time comparison with the preset target temperature value of the second process temperature curve;

[0039] When the difference between the actual temperature change curve and the target temperature of the process curve is greater than the first temperature preset value, the heating state is automatically switched to the heat preservation state, and the output power working condition parameters of the electric heater of the PID control algorithm are adjusted;

[0040] When the difference between the actual temperature change curve and the target temperature of the process curve is less than the second temperature preset value, the current heating process continues to run;

[0041] When the absolute value of the difference between the highest or lowest temperature of the superconducting coil and the user's target temperature is less than or equal to the user's required temperature difference, and the absolute value of the difference increases, the stirring fan speed is increased.

[0042] The present invention has the following beneficial effects:

[0043] 1. This invention uses an electric heating system in the low-temperature stage to fully utilize its high-precision temperature control capabilities and avoid temperature fluctuations caused by premature gas introduction. In the high-temperature stage, gas heating is introduced to supplement high power demand, utilizing the high energy density of gas combustion to significantly reduce peak power loads. At the same time, by dynamically allocating the power ratio of gas and electric heating, energy utilization efficiency is maximized. This makes it suitable for complex heat treatment scenarios such as nuclear fusion superconducting coils, which require both large size and high uniformity.

[0044] 2. The present invention detects the actual temperature of each temperature-controlled zone of the heating furnace body and the superconducting coil in real time, and compares it with the preset target temperature value of the corresponding process temperature curve in real time. The top layer is combined with dynamic adjustment of the stirring fan speed and gas-electric power complementation to form a closed-loop feedback chain from the local to the whole, effectively improving the response speed and stability. It is suitable for superconducting coil heat treatment processes with long cycles and high uniformity requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a principle block diagram of the nuclear fusion superconducting coil heat treatment temperature control system proposed by the present invention;

[0046] Figure 2 This is the process flow chart of the nuclear fusion superconducting coil heat treatment temperature control method proposed by the present invention Figure 1 ;

[0047] Figure 3 This is the process flow chart of the nuclear fusion superconducting coil heat treatment temperature control method proposed by the present invention Figure 2 ;

[0048] Figure 4 This is the process flow chart of the nuclear fusion superconducting coil heat treatment temperature control method proposed by the present invention Figure 3 ;

[0049] Figure 5 This is the process flow chart of the nuclear fusion superconducting coil heat treatment temperature control method proposed by the present invention Figure 4 .

[0050] Legend:

[0051] 1. Gas heating control subsystem; 11. Gas power control module; 12. Gas nozzle; 2. Electric heating control subsystem; 21. Electric heating power control module; 22. Electric heater; 3. Wind speed control subsystem; 31. Fan speed control module; 32. Stirring fan; 33. Stirring shaft; 34. Centrifugal impeller; 4. Temperature acquisition subsystem; 41. Thermocouple; 5. Temperature analysis feedback subsystem; 51. Temperature analysis feedback module; 6. Vacuum crucible; 7. Superconducting coil; 8. Heating furnace body. DETAILED DESCRIPTION

[0052] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0053] The embodiment of the present application provides a temperature control system and method for the heat treatment of nuclear fusion superconducting coils, which solves the problem that the existing electric heating furnace needs to be equipped with a very high power reserve for the heat treatment process of large superconducting coils, and a backup power supply is configured to prevent the loss of heating capacity due to power failure; the gas heating furnace has low power temperature control accuracy, resulting in poor heat treatment effect. The present application uses an electric heating system in the low-temperature stage to give full play to its high-precision temperature control capability and avoid temperature fluctuations caused by premature gas introduction; introduces gas heating in the high-temperature stage to supplement the high power demand, and utilizes the high energy density characteristics of gas combustion to significantly reduce the peak power load. At the same time, by dynamically allocating the power ratio of gas and electric heating, the energy utilization efficiency is maximized. It is suitable for complex heat treatment scenarios such as nuclear fusion superconducting coils that require both large size and high uniformity.

[0054] Please refer to the following examples for details:

[0055] Reference Figure 1 The present invention provides an embodiment of a nuclear fusion superconducting coil heat treatment temperature control system, the specific structure of which includes: a gas heating control subsystem 1, an electric heating control subsystem 2, a wind speed control subsystem 3, a temperature acquisition subsystem 4 and a temperature analysis and feedback subsystem 5, wherein:

[0056] (1) Gas heating control subsystem 1: With the gas power control module 11 as the core, it ensures that the heat energy output during the heat treatment process accurately matches the process requirements by precisely controlling the heating and insulation parameters of the gas nozzles 12. Specifically, the gas nozzles 12 are divided into three groups: the top zone, the middle zone, and the bottom zone, and are symmetrically distributed along the longitudinal vertical center section of the heating furnace body 8. Each group of nozzles is equipped with an independent high-temperature electric butterfly valve, an air-fuel ratio valve, and a gas solenoid valve (as a prior art, not shown in the figure); the high-temperature electric butterfly valve controls the combustion efficiency by adjusting the air intake volume, and the air-fuel ratio valve dynamically adjusts the mixing ratio of gas and air (for example, 1:10-1:15) to ensure sufficient combustion without carbon deposits; the gas solenoid valve acts as a safety switch and is only turned on when the system detects that the lowest coil temperature is greater than a preset value (for example, a temperature ≥300°C), to avoid accidental start-up of the gas in the low-temperature stage.

[0057] For example, during the insulation phase (temperature > 300°C), the gas power control module 11 proportionally distributes the gas flow (e.g., a 200kW gap corresponds to a 60% increase in the gas valve opening) based on the difference between the target power demand (e.g., 500kW) and the remaining electric heating power. Simultaneously, it monitors the maximum crucible temperature in real time to ensure it does not exceed the minimum coil temperature. This hierarchical control strategy ensures combustion stability while enabling continuous adjustment of gas power, significantly reducing peak power load (approximately 30%-40%) and making it suitable for high-power superconducting coil 7 heat treatment scenarios.

[0058] (2) Electric Heating Control Subsystem 2: The core is the electric heating power control module 21, which achieves high-precision temperature regulation through zoned independent temperature control technology. Specifically, the electric heater 22 is embedded in the inner wall of the vacuum crucible 6 in a ring-shaped layout. The coil shape is divided into multiple independent temperature zones (such as the top zone, the middle zone, and the bottom zone). Each temperature zone is equipped with an independent PID controller and power regulation unit.

[0059] For example, in the low-temperature stage (temperature ≤ 300°C), the system prioritizes electric heating, and each temperature zone dynamically adjusts the output power through the PID algorithm based on the temperature data fed back by the N-type thermocouple 41. For example, when the actual temperature in a temperature zone is 5°C lower than the target value, the PID controller increases the power to 80% of the rated value and calculates the integral error in real time to eliminate steady-state deviations. If the temperature difference exceeds ±10°C, an alarm is triggered and the temperature increase is suspended. The partitioned design of the electric heater 22, combined with a closed-loop feedback mechanism, can stabilize the local temperature control accuracy within ±3°C and the overall uniformity below ±5°C. It is particularly suitable for the heat treatment of superconducting coils 7 made of Nb3Sn material that is sensitive to thermal stress.

[0060] It is understandable that the electric heating system works in conjunction with gas heating in the high-temperature stage, further improving the system's anti-interference ability by dynamically compensating for gas power fluctuations (for example, when a sudden increase in gas causes local overtemperature, the electric heating power is automatically reduced).

[0061] (3) Wind Speed ​​Control Subsystem 3: Dynamically adjusts the operating parameters of the stirring fan 32 through the fan speed control module 31 to optimize the airflow distribution within the furnace and eliminate temperature gradients. Specifically, the stirring fan 32 is installed on the top of the heating furnace body 8 and is rotatably connected to the centrifugal impeller 34 via the stirring shaft 33. The stirring fan 32 then adjusts its speed according to the instructions of the temperature analysis feedback module 51.

[0062] For example, when the maximum coil temperature is detected to deviate from the target value by more than 5°C, the fan speed is increased linearly (10% for every 2°C temperature difference), forcing the airflow to circulate along the guide channel, focusing on improving heat transfer efficiency in low-temperature areas. Understandably, the fan system is linked to the gas-electric heating subsystem and starts simultaneously during the insulation phase. By enhancing convective heat transfer and reducing the effects of thermal inertia, the temperature uniformity within the furnace is improved to within ±3°C. This intelligent speed regulation mechanism not only shortens temperature equilibration time but also reduces fan energy consumption, making it suitable for long-cycle, high-uniformity heat treatment processes.

[0063] (4) Temperature acquisition subsystem 4: It consists of a network of high-precision thermocouples 41, including two types of temperature sensors: furnace body thermocouples and workpiece thermocouples. Specifically, the furnace body thermocouples are evenly distributed on the inner wall of the vacuum crucible 6, arranged in a circular pattern with equal angles along the longitudinal vertical centerline (for example, one group is arranged every 30-60 degrees), and monitor the surface temperature of the inner wall of each area of ​​the crucible in real time. Correspondingly, the workpiece thermocouples are directly set inside the superconducting coil 7, and are evenly spaced along the axial direction of the coil (for example, one group is arranged every 30-60 degrees), and accurately feedback the temperature field distribution of the coil body.

[0064] For example, all thermocouple 41 signals are transmitted via shielded cables to an industrial computer acquisition system with a sampling frequency of 10Hz, ensuring real-time data. During the heating phase, by comparing the furnace thermocouple and workpiece thermocouple data (e.g., crucible temperature 320°C - coil temperature 305°C), the heating strategy is dynamically adjusted to avoid temperature control deviations caused by heat conduction delays. The dual-sensor redundant design further enhances reliability. If a sensor fails, the system automatically switches to the backup signal and triggers a maintenance alarm, ensuring process continuity.

[0065] (5) Temperature analysis and feedback subsystem 5: As the control center, the temperature analysis and feedback module 51 runs the temperature control algorithm (such as PID temperature control algorithm, etc.) to analyze the temperature curve and temperature uniformity parameters, and generates a feedback control scheme for the heat treatment adjustment process. Specifically, the temperature analysis and feedback module 51 is electrically connected to the gas power control module 11, the electric heating power control module 21, the fan speed control module 31 and the thermocouple 41 through a data transmission line to achieve real-time communication, thereby building a hierarchical closed-loop control system.

[0066] It can be understood that the superconducting coil 7 is placed inside the vacuum crucible 6, an electric heater 22 is arranged around the outer wall of the crucible, a gas nozzle 12 is arranged on the inner wall of the heating furnace body 8, and a stirring fan 32 is installed on the top, forming a "electric-gas-wind" three-in-one heating and temperature equalization system: in the low temperature stage, the electric heating system relies on the zoned PID temperature control capability to accurately operate the temperature control process curve; when the temperature exceeds the 300°C threshold, the gas system intervenes to supplement the high power demand through the coordinated combustion of multi-zone nozzles, and at the same time, the temperature field is balanced by forced circulating airflow through the fan, which can effectively eliminate the axial temperature gradient and improve the local and overall temperature control accuracy, effectively adapting to the high-standard heat treatment requirements of the large superconducting coil 7 of the nuclear fusion device.

[0067] Reference Figure 2-Figure 5 The present invention further provides an embodiment of a method for controlling the heat treatment temperature of a nuclear fusion superconducting coil 7, which is executed by the temperature control system for the heat treatment of the nuclear fusion superconducting coil 7 in the above embodiment. The temperature control method includes:

[0068] S100, inputting the user's target temperature curve and uniform heating parameter process for heat treatment;

[0069] S200, performing the electric heating zone temperature control process during the low-temperature stage of heat treatment, and real-time detection and judgment on whether to switch to the heating or insulation process;

[0070] S300: Perform the coordinated temperature control process of gas heating and electric heating in the high-temperature stage of heat treatment, and detect and judge in real time whether to switch to the heating or insulation process and the temperature equalization process.

[0071] For example, when setting the user target temperature curve and uniformity heating parameter process of heat treatment, a preset temperature process curve is imported, which includes key parameters such as heating rate, holding temperature and holding time, and the temperature uniformity requirements are set at the same time. These parameters will then be automatically analyzed and a corresponding feedback control scheme will be generated; when performing the electric heating zone temperature control process in the heat treatment heating stage and the gas heating and electric heating zone collaborative temperature control process in the heat treatment insulation stage, multi-system collaborative control is used to ensure that the temperature uniformity is always maintained within the range of process requirements. This method effectively solves the problems of temperature uniformity and temperature control accuracy during the heat treatment process of large superconducting coil 7 through intelligent hierarchical temperature control and dynamic collaboration of multiple systems.

[0072] Please continue reading Figure 3 In this embodiment, S100 includes:

[0073] S110, importing or inputting a target process temperature curve through an input interface and setting temperature uniformity parameters;

[0074] S120, analyzing the temperature curve and temperature uniformity parameters, and generating a feedback control scheme for the heat treatment adjustment process.

[0075] For example, during the initial configuration of a heat treatment process, operators can use the industrial computer's human-machine interface (HMI) or dedicated control software to import pre-existing standardized process temperature curve templates or manually enter customized temperature control parameters based on the specific requirements of the workpiece being processed. These parameters include, but are not limited to, key process indicators such as the initial temperature, multi-stage heating rates (e.g., 50°C / h to 300°C, 100°C / h to 650°C), target temperatures for each holding stage (e.g., 300°C, 450°C, 650°C), corresponding holding times, and maximum allowable cooling rates. Temperature uniformity control parameters also need to be set, including the maximum allowable temperature difference across the workpiece surface (e.g., ±5°C) and uniformity tolerances for different temperature ranges (e.g., ±8°C below 300°C, ±5°C above 300°C). The system then performs format and logic checks on the input parameters to ensure the continuity and enforceability of the process curve.

[0076] Subsequently, based on the built-in thermodynamic model and process knowledge base, combined with the structural characteristics of the current heat treatment furnace, the heating power configuration, the size specifications of the superconducting coil 7 to be treated (for example, a diameter of 5m, a weight of 8 tons, etc.) and the material properties (for example, the heat capacity and thermal conductivity of Nb3Sn, etc.), the optimal temperature regulation strategy is automatically analyzed and calculated, and finally a heat treatment regulation process feedback control plan is generated, which includes control parameters such as the electric heating power distribution plan, the timing of gas intervention, and the fan speed regulation strategy.

[0077] Please continue reading Figure 4 In this embodiment, S200 includes:

[0078] S210, self-checking the working status of all temperature-controlled zone thermocouples 41 and reading the first process temperature curve;

[0079] S220, real-time detection of the temperature values ​​of the heating furnace body 8 and the superconducting coil 7 fed back by the thermocouples 41 of all temperature-controlled zones, and analysis of the current temperature change trend;

[0080] S230, based on the feedback control scheme of the heat treatment adjustment process, converting it into a first target preset operating parameter temperature control instruction sequence, sending a state switching signal control signal to adjust the heating operating parameters of the electric heater 22;

[0081] S240, the electric heater 22 runs a heating process or a heat preservation process based on a heating state or a heat preservation state switching signal, and the stirring fan 32 runs a temperature equalization process based on a heating state or a heat preservation state switching signal.

[0082] For example, during the electric heating zone temperature control process during the heat treatment heating stage, a self-test program is first executed to perform a comprehensive status test on the multiple groups of N-type thermocouples 41 distributed at the corresponding positions of the vacuum crucible 6 and the superconducting coil 7 in the temperature control zone, including checking the sensor line impedance (normal range 0-10Ω), signal transmission stability (fluctuation amplitude <0.1mV) and cold end compensation accuracy (error <±0.5℃); at the same time, a pre-set first process temperature curve is called from the process database, which sets the temperature in steps from room temperature to 300℃ in detail. The system calculates the temperature rise gradient of each section (e.g. 50°C / h in the 0-200°C range, 30°C / h in the 200-300°C range) and the holding time requirements for each temperature node; after confirming that all thermocouples 41 are working properly, the internal ambient temperature of the furnace body and the surface temperature data of the superconducting coil 7 fed back by the thermocouples 41 of each partition are synchronously obtained, and the operating parameters such as the temperature rise rate, maximum temperature difference and temperature distribution standard deviation of each partition are calculated in real time. When it is detected that the temperature rise rate of a partition deviates from the set value by more than 15% or the temperature difference between adjacent partitions exceeds 20°C, the system will trigger the early warning mechanism.

[0083] It should be explained in detail that the first target preset operating condition parameter temperature control instruction sequence includes:

[0084] Real-time detection of the actual temperature of each temperature-controlled zone of the heating furnace body 8 and the superconducting coil 7, and real-time comparison with the preset target temperature value of the first process temperature curve;

[0085] When the difference between the actual temperature change curve and the target temperature of the process curve is greater than the first temperature range, the heating state is automatically switched to the heat preservation state, and the output power operating parameters of the electric heater 22 of the PID control algorithm are adjusted;

[0086] When the difference between the actual temperature change curve and the target temperature of the process curve is less than the second temperature range, the current heating process continues to run;

[0087] When the absolute value of the difference between the highest or lowest temperature of the superconducting coil 7 and the user's target temperature is less than or equal to the user's required temperature difference, and the absolute value of the difference increases, the rotation speed of the stirring fan 32 is increased.

[0088] For example, based on the above real-time monitoring data, the system will dynamically generate a first target preset operating condition parameter temperature control instruction sequence according to the pre-generated heat treatment adjustment process feedback control scheme. Specifically, the core control logic of the instruction sequence includes:

[0089] 1) Establish a multi-level temperature comparison mechanism to compare the actual temperature of each temperature control zone with the target value at the corresponding time node in the first process temperature curve in real time;

[0090] 2) When the deviation between the actual temperature and the target value in any zone exceeds a first temperature range (e.g., greater than ±10°C), the system immediately interrupts the preset heating program and automatically switches to the insulation control mode. At this time, the temperature control algorithm activates a three-level response mechanism: first, the fuzzy PID controller (e.g., proportional coefficient Kp = 0.8, integral time Ti = 120s, differential time Td = 20s) quickly adjusts the output power of the electric heater 22 in that zone (e.g., adjustment range of 5%-20%), and simultaneously links the heating elements of the two adjacent zones for coordinated compensation (e.g., the power adjustment range is 50% of the abnormal zone);

[0091] 3) When the system detects that the temperature deviations of all zones have fallen back to the second temperature range (e.g., ±5°C) and remain stable for more than one sampling period (e.g., 30 seconds), it automatically resumes the original heating process to ensure that there will be no power mutation (e.g., a single adjustment range of less than 25%) or over-temperature risk (e.g., the maximum temperature is less than the material's maximum temperature resistance).

[0092] Please continue reading Figure 5 In this embodiment, S300 includes:

[0093] S310, self-checking the working status of all temperature-controlled zone gas nozzles 12 and reading the second process temperature curve;

[0094] S320, real-time detection of the temperature values ​​of the heating furnace body 8 and the superconducting coil 7 fed back by the thermocouples 41 of all temperature-controlled zones, and analysis of the current temperature change trend;

[0095] S330, based on the feedback control scheme of the heat treatment adjustment process, converting it into a second target preset operating parameter temperature control instruction sequence, sending a state switching signal control signal to adjust the heating operating parameters of the electric heater 22, the gas nozzle 12 and the stirring fan 32;

[0096] S340, the electric heater 22 and the gas nozzle 12 run the heating or keeping warm process based on the heating state or keeping warm state switching signal, and the stirring fan 32 runs the temperature equalization process based on the temperature.

[0097] For example, in the gas-electric heating coordinated temperature control process during the heat treatment insulation stage, the gas system self-test program is first executed to perform status detection on multiple groups of temperature-controlled zoned gas nozzles 12 distributed at corresponding positions of the heating furnace body 8, including solenoid valve response time test (e.g., response time <500ms), air-fuel ratio valve opening calibration (e.g., opening error <±2%), gas pressure monitoring (e.g., maintained at 0.25±0.05MPa), etc.; at the same time, the second process temperature curve is retrieved from the process database, which sets in detail the temperature rise gradient from 300°C to the final temperature (e.g., 650°C) (e.g., 40°C / h in the 300-500°C range, 20°C / h in the 500-650°C range) and the temperature uniformity requirements (e.g., temperature fluctuation in the 650°C insulation stage must be controlled within ±3°C).

[0098] After entering the real-time monitoring stage, the distributed temperature acquisition network composed of thermocouples 41 is used to collect the real-time temperatures of different temperature-controlled areas in the heating furnace body 8 and the vacuum crucible 6, and the temperature gradient distribution, heat flux density change trend and response lag time of each control loop are calculated in real time. When the system recognizes abnormal temperature characteristics (such as a sudden change in the temperature rise rate in a certain area greater than 10°C / min or a temperature difference between adjacent nozzles greater than 25°C), the diagnostic subroutine is immediately started to locate the potential fault source.

[0099] It should be explained in detail that the second target preset operating condition parameter temperature control instruction sequence includes:

[0100] Real-time detection of the actual temperature of each temperature-controlled zone of the heating furnace body 8 and the superconducting coil 7, and real-time comparison with the preset target temperature value of the second process temperature curve;

[0101] When the difference between the actual temperature change curve and the target temperature of the process curve is greater than the first temperature preset value, the heating state is automatically switched to the heat preservation state, and the output power operating parameters of the electric heater 22 of the PID control algorithm are adjusted;

[0102] When the difference between the actual temperature change curve and the target temperature of the process curve is less than the second temperature preset value, the current heating process continues to run;

[0103] When the absolute value of the difference between the highest or lowest temperature of the superconducting coil 7 and the user's target temperature is less than or equal to the user's required temperature difference, and the absolute value of the difference increases, the rotation speed of the stirring fan 32 is increased.

[0104] For example, a second target preset operating condition parameter temperature control instruction sequence is generated based on the real-time analysis result, and the sequence includes a multi-level control strategy:

[0105] 1) Temperature-power closed-loop regulation: When the deviation between the actual temperature and the target value detected in any temperature-controlled zone exceeds a first preset value (e.g., >+3°C), a gradient power reduction strategy is implemented, first reducing the electric heating power of the corresponding zone (in steps of 10% / time), while adjusting the air-fuel ratio of the gas nozzle 12 (in steps of 0.5%), and starting the compensatory heating of the two adjacent zones. When the temperature difference narrows to within a second preset value (e.g., <-3°C), a gradient power increase strategy is implemented, first increasing the electric heating power of the corresponding zone (in steps of 10% / time), while adjusting the air-fuel ratio of the gas nozzle 12 (in steps of 0.5%), and turning off the compensatory heating of the two adjacent zones.

[0106] 2) Dynamic wind field control: The deviation ΔT between the maximum / minimum coil surface temperature and the set value is calculated in real time. When the absolute value of the difference between the maximum or minimum coil temperature and the user's target temperature is less than the target requirement value (for example, ±5°C), the fan speed is adjusted in stages according to the change rate (the base speed is 800 rpm, and each 0.5°C / min change corresponds to an increase of 100 rpm).

[0107] Through the above technical solution, the present application uses an electric heating system in the low-temperature stage to give full play to its high-precision temperature control capability and avoid temperature fluctuations caused by premature gas intervention; introduces gas heating in the high-temperature stage to supplement high-power demand, and utilizes the high energy density characteristics of gas combustion to significantly reduce the peak power load. At the same time, by dynamically allocating the power ratio of gas and electric heating, energy utilization efficiency is maximized, which is suitable for complex heat treatment scenarios such as nuclear fusion superconducting coils 7 that require both large size and high uniformity; real-time detection of the actual temperature of each temperature control zone of the heating furnace body 8 and the superconducting coil 7, and real-time comparison with the preset target temperature value of the corresponding process temperature curve, the top layer is combined with the dynamic adjustment of the speed of the stirring fan 32 and the gas-electric power complementation to form a closed-loop feedback chain from the local to the whole, which effectively improves the response speed and stability, and is suitable for long-cycle, high-uniformity superconducting coil 7 heat treatment processes.

[0108] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A control method for a nuclear fusion superconducting coil heat treatment temperature control system, characterized in that: The control system includes: The gas heating control subsystem includes a gas power control module, which is used to control the heating and insulation working parameters of the gas nozzle; The electric heating control subsystem includes an electric heating power control module, which is used to control the heating and heat preservation working parameters of the electric heater; The wind speed control subsystem includes a fan speed control module, which is used to control the speed operating parameters of the stirring fan; A temperature acquisition subsystem, including a thermocouple, which is used to collect temperature parameters of the vacuum crucible and the superconducting coil; A temperature analysis and feedback subsystem, comprising a temperature analysis and feedback module, which is electrically connected to the gas power control module, the electric heating power control module, the fan speed control module, and the thermocouple. The temperature analysis and feedback module is used to monitor the temperature of the vacuum crucible and the superconducting coil, analyze target preset operating parameters, and generate a feedback control plan for the heat treatment adjustment process; The control method includes: S100, inputting the user's target temperature curve and uniform heating parameter process for heat treatment; S200, performing the electric heating zone temperature control process during the low-temperature stage of heat treatment, and real-time detection and judgment on whether to switch to the heating or insulation process; S300: Performing the coordinated temperature control process of gas heating and electric heating in the high-temperature stage of heat treatment, and real-time detection and judgment on whether to switch to the heating or insulation process and the temperature equalization process; The S200 includes: S210, self-checking the working status of all temperature-controlled zone thermocouples and reading the first process temperature curve; S220: Real-time detection of the temperature values ​​of the heating furnace and superconducting coils fed back by thermocouples in all temperature-controlled zones, and analysis of the current temperature change trend; S230, based on the feedback control scheme of the heat treatment adjustment process, converting it into a first target preset operating parameter temperature control instruction sequence, sending a state switching signal control signal to adjust the heating operating parameters of the electric heater; S240, the electric heater runs a heating or keeping warm process based on the heating state or keeping warm state switching signal, and the stirring fan runs a temperature equalization process based on the temperature; The S300 includes: S310, self-check the working status of all temperature-controlled zone gas nozzles and read the second process temperature curve; S320: Real-time detection of the temperature values ​​of the heating furnace and superconducting coils fed back by thermocouples in all temperature-controlled zones, and analysis of the current temperature change trend; S330, based on the feedback control scheme for the heat treatment adjustment process, converting the sequence of temperature control instructions to the second target preset operating parameters, and sending a state switching signal control signal to adjust the heating operating parameters of the electric heater, the gas nozzle, and the stirring fan; S340, the electric heater and the gas nozzle run a heating or keeping warm process based on the heating state or keeping warm state switching signal, and the stirring fan runs a temperature equalization process based on the temperature.

2. The control method of the nuclear fusion superconducting coil heat treatment temperature control system according to claim 1, characterized in that: The superconducting coil is placed inside the vacuum crucible, an electric heater is arranged around the inner wall of the vacuum crucible, a heating furnace body is arranged outside the vacuum crucible, a gas nozzle is arranged around the inner wall of the heating furnace body, a stirring fan is installed on the top of the heating furnace body, and the stirring fan is rotatably connected to the centrifugal impeller through a stirring shaft.

3. The control method of the nuclear fusion superconducting coil heat treatment temperature control system according to claim 2, characterized in that: The gas nozzle includes a top nozzle, a middle nozzle and a bottom nozzle, which divide the heating furnace body into the top, middle and bottom areas. The gas nozzles are symmetrically distributed along the longitudinal vertical center section of the heating furnace body. The gas nozzle is connected to a control valve, which includes a high-temperature electric butterfly valve, an air-fuel ratio valve and a gas solenoid valve. The control valve is electrically connected to the gas power control module.

4. The control method of the nuclear fusion superconducting coil heat treatment temperature control system according to claim 1, characterized in that: The thermocouple includes a furnace body couple and a workpiece couple. The furnace body couple is arranged on the inner wall of the vacuum crucible, and the furnace body couple is arranged in a circular direction at equal angles along the longitudinal vertical center of the heating furnace body. The workpiece couple is arranged on the superconducting coil, and the workpiece couple is arranged in a circular direction at equal angles along the longitudinal vertical center of the superconducting coil.

5. The control method of the nuclear fusion superconducting coil heat treatment temperature control system according to claim 1, characterized in that: The S100 includes: S110, importing or inputting a target process temperature curve through an input interface and setting temperature uniformity parameters; S120, analyzing the temperature curve and temperature uniformity parameters, and generating a feedback control scheme for the heat treatment adjustment process.

6. The control method of the nuclear fusion superconducting coil heat treatment temperature control system according to claim 1, characterized in that: The first target preset operating condition parameter temperature control instruction sequence includes: Real-time detection of the actual temperature of each temperature-controlled zone of the heating furnace body and the superconducting coil, and real-time comparison with the preset target temperature value of the first process temperature curve; When the difference between the actual temperature change curve and the target temperature of the process curve is greater than the first temperature range, the heating state is automatically switched to the heat preservation state, and the output power operating condition parameters of the electric heater of the PID control algorithm are adjusted; When the difference between the actual temperature change curve and the target temperature of the process curve is less than the second temperature range, the current heating process continues to run; When the absolute value of the difference between the highest or lowest temperature of the superconducting coil and the user's target temperature is less than or equal to the user's required temperature difference, and the absolute value of the difference increases, the stirring fan speed is increased.

7. The control method of the nuclear fusion superconducting coil heat treatment temperature control system according to claim 1, characterized in that: The second target preset operating condition parameter temperature control instruction sequence includes: Real-time detection of the actual temperature of each temperature-controlled zone of the heating furnace body and superconducting coil, and real-time comparison with the preset target temperature value of the second process temperature curve; When the difference between the actual temperature change curve and the target temperature of the process curve is greater than the first temperature preset value, the heating state is automatically switched to the heat preservation state, and the output power working condition parameters of the electric heater of the PID control algorithm are adjusted; When the difference between the actual temperature change curve and the target temperature of the process curve is less than the second temperature preset value, the current heating process continues to run; When the absolute value of the difference between the highest or lowest temperature of the superconducting coil and the user's target temperature is less than or equal to the user's required temperature difference, and the absolute value of the difference increases, the stirring fan speed is increased.

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