Nuclear fusion superconducting coil heat treatment temperature control system and method

Abstract

The invention discloses a nuclear fusion superconducting coil heat treatment temperature control system and method. The temperature control system comprises a fuel gas heating control subsystem, an electric heating control subsystem, a wind speed control subsystem, a temperature acquisition subsystem and a temperature analysis feedback subsystem. The temperature control method comprises the following steps: performing an electric heating zoning temperature control process in a heat treatment temperature rise stage; and a gas heating and electric heating zoning cooperative temperature control process in the heat treatment heat preservation stage is carried out. According to the method, the power load peak value is remarkably reduced, and meanwhile, the method is suitable for the heat treatment scene of the nuclear fusion superconducting coil by dynamically distributing the power proportion of gas and electric heating; the actual temperature of each temperature control subarea of the heating furnace body and the superconducting coil is detected in real time and compared with the preset target temperature value of the corresponding process temperature curve in real time, the top layer is combined with stirring fan rotating speed dynamic adjustment and gas-electric power complementation, a closed-loop feedback chain from a local part to an overall part is formed, and the response speed and stability are effectively improved.

Description

Technical Field

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

[0002] In the manufacturing and forming process of nuclear fusion superconducting coils, due to the special nature of Nb3Sn materials, which are sensitive to stress and strain, the coils will adopt the technology of "winding first and then reacting" to complete the coil manufacturing. That is, after the coils are wound, they must undergo heat treatment to undergo a solid-state diffusion reaction to form the A15-type Nb3Sn superconducting phase, thereby generating superconductivity. The formation of the Nb3Sn superconducting phase strongly depends on the heat treatment process, and the superconducting coils need to be heat-treated in an environment of several hundred degrees for more than dozens of days. Currently, the main heat treatment method is to place the coils in a dedicated heat treatment device for continuous vacuum heating.

[0003] For the heat treatment of Nb3Sn superconducting coils, temperature uniformity is a key technical index for the heat treatment of Nb3Sn superconducting coils. In existing metal phase heat treatment furnaces, the temperature control system of the electric power source heating furnace uses the temperature on the surface of the coil as feedback, and controls the temperature of the coil by controlling the power of the heating element through a power controller. Although the temperature control accuracy is relatively high, since it uses electricity as the only heating source, a very high power reserve needs to be equipped for the heat treatment process of large superconducting coils, and a backup power source needs to be configured to prevent the loss of heating ability due to power failure; while the gas heating furnace controls the temperature by adjusting the flow rate of combustible gas, that is, by adjusting the ratio of gas and oxidant according to the power requirements in different stages, or by adjusting the total flow rate of the mixed gas. However, the gas power is released rapidly, so the power temperature control accuracy (especially the temperature control accuracy in the low-temperature stage) is relatively low, resulting in poor heat treatment effects. Summary of the Invention

[0004] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

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

[0006] To achieve the above purpose, in the first aspect, the present invention provides a heat treatment temperature control system for a nuclear fusion superconducting coil, including: The gas heating control subsystem includes a gas power control module, and the gas power control module is used to control the heating and heat preservation working condition parameters of the gas nozzle; The electric heating control subsystem includes an electric heating power control module, and the electric heating power control module is used to control the heating and heat preservation working condition parameters of the electric heater; The wind speed control subsystem includes a fan speed control module, and the fan speed control module is used to control the speed working condition parameters of the stirring fan; The temperature acquisition subsystem includes a thermocouple, and the thermocouple is used to acquire the temperature working condition parameters of the vacuum crucible and the superconducting coil; The temperature analysis and feedback subsystem includes a temperature analysis and feedback module. The temperature analysis and feedback module 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 the target preset working condition parameters and generate a feedback control scheme for the heat treatment adjustment process.

[0007] In some embodiments, the superconducting coil is placed inside the vacuum crucible. The inner wall of the vacuum crucible is provided with electric heaters in a circular arrangement. A heating furnace body is arranged outside the vacuum crucible. The inner wall of the heating furnace body is provided with gas nozzles in a circular arrangement. A stirring fan is installed at the top of the heating furnace body. The stirring fan is rotationally connected to a centrifugal impeller through a stirring shaft.

[0008] In some embodiments, the gas nozzle includes a top zone nozzle, a middle zone nozzle and a bottom zone nozzle, dividing the heating furnace body into a top zone, a middle zone and a bottom zone. The gas nozzles are symmetrically distributed along the longitudinal vertical central section of the heating furnace body. The gas nozzle is connected with a control valve. 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.

[0009] In some embodiments, the thermocouple includes a furnace body thermocouple and a workpiece thermocouple. The furnace body thermocouple is arranged on the inner wall of the vacuum crucible and is arranged in an equiangular circumferential manner along the longitudinal vertical center of the heating furnace body. The workpiece thermocouple is arranged on the superconducting coil and is arranged in an equiangular circumferential manner along the longitudinal vertical center of the superconducting coil.

[0010] In a second aspect, the present invention also provides a method for controlling the heat treatment temperature of a nuclear fusion superconducting coil, which is executed via the nuclear fusion superconducting coil heat treatment temperature control system as described in the first aspect. The temperature control method includes: S100, input the heat treatment user target temperature curve and the uniform heating parameter process; S200, perform the electric heating zone temperature control process in the low-temperature stage of the heat treatment, and detect and judge in real time whether to switch to the heating or heat preservation process; In S300, a collaborative temperature control process for gas heating and electric heating in the high-temperature stage of heat treatment is carried out, and it is detected and judged in real time whether to switch to the heating-up or heat-preservation process and the temperature equalization process.

[0011] In some of these embodiments, 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 to generate a feedback control scheme for the heat treatment adjustment process.

[0012] In some of these embodiments, the S200 includes: S210, self-checking the working status of the thermocouples in all temperature control zones and reading the first process temperature curve; S220, detecting in real time the temperature values of the heating furnace body and the superconducting coil feedback by the thermocouples in all temperature control zones and analyzing the current temperature change trend; S230, based on the feedback control scheme of the heat treatment adjustment process, converting it into a control instruction sequence of the first target preset working condition parameters, and sending a status switching signal control signal to adjust the heating working condition parameters of the electric heater; S240, the electric heater runs the heating-up or heat-preservation process based on the heating-up state or heat-preservation state switching signal, and the stirring fan runs the temperature equalization process based on the heating-up state or heat-preservation state switching signal of the temperature.

[0013] In some of these embodiments, the control instruction sequence of the first target preset working condition parameters includes: Detecting in real time the actual temperature of each temperature control zone of the heating furnace body and the superconducting coil, and comparing it in real time 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, automatically switch from the heating-up state to the heat-preservation state, and adjust the working condition parameters of the output power of the electric heater by the PID control algorithm; When the difference between the actual temperature change curve and the target temperature of the process curve is less than the second temperature range, continue to run the current heating-up process; When the absolute value of the difference between the highest or lowest temperature of the superconducting coil and the user target temperature is less than or equal to the user required temperature difference value, and the absolute value of the difference increases, increase the rotation speed of the stirring fan.

[0014] In some of these embodiments, the S300 includes: S310, self-checking the working status of the gas nozzles in all temperature control zones and reading the second process temperature curve; S320, detecting in real time the temperature values of the heating furnace body and the superconducting coil feedback by the thermocouples in all temperature control zones and analyzing the current temperature change trend; S330, based on the feedback control scheme of the heat treatment adjustment process, convert it into a temperature control instruction sequence for the second target preset working condition parameters, and send a status switching signal control signal to adjust the heating working condition parameters of the electric heater, gas nozzle, and stirring fan; S340, the electric heater and gas nozzle operate the heating or heat preservation process based on the heating or heat preservation state switching signal, and the stirring fan operates the temperature equalization process based on the temperature based on the heating or heat preservation state switching signal.

[0015] In some embodiments, the temperature control instruction sequence for the second target preset working condition parameters includes: Real-time detect the actual temperature of each temperature control zone of the heating furnace body and superconducting coil, and compare it in real-time 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, automatically switch from the heating state to the heat preservation state, and adjust the power output working condition parameters of the electric heater by the PID control algorithm; 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, continue to run the current heating process; 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 value, and the absolute value of the difference increases, increase the rotation speed of the stirring fan.

[0016] The present invention has the following beneficial effects: 1. In the present invention, the electric heating system is used in the low-temperature stage to give full play to its high-precision temperature control ability and avoid temperature fluctuations caused by premature gas intervention; in the high-temperature stage, gas heating is introduced to supplement the high-power demand, and the high energy density characteristics of gas combustion are utilized to significantly reduce the peak power load. At the same time, by dynamically distributing the power ratio of gas and electric heating, the maximization of energy utilization efficiency is realized, which is applicable to complex heat treatment scenarios such as nuclear fusion superconducting coils that need to balance large size and high uniformity; 2. In the present invention, the actual temperature of each temperature control zone of the heating furnace body and superconducting coil is detected in real-time, and compared in real-time with the preset target temperature value of the corresponding process temperature curve. The top layer combines the dynamic adjustment of the stirring fan rotation speed and the complementarity of gas-electric power to form a closed-loop feedback chain from local to overall, effectively improving the response speed and stability, and is applicable to the heat treatment process of superconducting coils with long cycles and high uniformity requirements. Description of the Drawings

[0017] Figure 1 It is the principle block diagram of the heat treatment temperature control system for the nuclear fusion superconducting coil proposed by the present invention; Figure 2 It is the flow block of the heat treatment temperature control method for the nuclear fusion superconducting coil proposed by the present invention Figure 1 ; Figure 3 Flow chart of the heat treatment temperature control method for the nuclear fusion superconducting coil proposed by the present invention Figure 2 ; Figure 4 Flow chart of the heat treatment temperature control method for the nuclear fusion superconducting coil proposed by the present invention Figure 3 ; Figure 5 Flow chart of the heat treatment temperature control method for the nuclear fusion superconducting coil proposed by the present invention Figure 4 。

[0018] Legend: 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 and feedback subsystem; 51. Temperature analysis and feedback module; 6. Vacuum crucible; 7. Superconducting coil; 8. Heating furnace body. Detailed implementation manners

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0020] The embodiments of the present application provide a heat treatment temperature control system and method for a nuclear fusion superconducting coil, which solve the problems in the prior art that a power source heating furnace requires a very high power reserve for the heat treatment process of a large superconducting coil and is equipped with a backup power source to prevent the loss of heating ability due to a power failure; the power temperature control accuracy of a gas heating furnace is relatively low, resulting in poor heat treatment effects. The present application uses an electric heating system in the low-temperature stage to give full play to its high-precision temperature control ability and avoid temperature fluctuations caused by premature intervention of gas; in the high-temperature stage, gas heating is introduced to supplement the high-power demand, taking advantage of 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 maximum energy utilization efficiency is achieved, which is applicable to complex heat treatment scenarios such as nuclear fusion superconducting coils that require both large size and high uniformity.

[0021] Please refer to the following specific embodiments for details: Refer to Figure 1, An embodiment of a heat treatment temperature control system for a nuclear fusion superconducting coil provided by the present invention, the specific structure 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, where: (1) Gas heating control subsystem 1: With the gas power control module 11 as the core, by precisely regulating the heating and heat preservation condition parameters of the gas nozzle 12, it ensures that the heat energy output during the heat treatment process precisely matches the process requirements. Specifically, the gas nozzle 12 is divided into three groups: the top area, the middle area, and the bottom area, symmetrically distributed along the longitudinal vertical central section of the heating furnace body 8, and 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 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 (such as 1:10 - 1:15) to ensure full combustion and no carbon deposition; the gas solenoid valve serves as a safety switch and is only opened when the system detects that the lowest temperature of the coil is greater than a preset value (such as temperature ≥ 300°C) to avoid mis-starting of gas in the low-temperature stage.

[0022] Exemplarily, in the heat preservation stage (temperature > 300°C), the gas power control module 11 distributes the gas flow proportionally according to the difference between the target power demand (such as 500 kW) and the remaining power of the electric heating (such as a 200 kW gap corresponding to the gas valve opening being increased to 60%), and simultaneously monitors the highest temperature of the crucible in real time to ensure that it does not exceed the lowest temperature of the coil. It can be understood that this hierarchical control strategy not only ensures the combustion stability but also realizes the continuous adjustability of the gas power, significantly reducing the peak power load (about 30% - 40%), and is applicable to the heat treatment scenario of superconducting coils 7 with high power requirements.

[0023] (2) Electric heating control subsystem 2: The core is the electric heating power control module 21, which realizes high-precision temperature regulation through the independent temperature control technology for each zone. Specifically, the electric heaters 22 are embedded in the inner wall of the vacuum crucible 6 in a ring layout and are divided into multiple independent temperature zones (such as the top area, the middle area, and the bottom area) according to the shape of the coil, and each temperature zone is configured with an independent PID controller and a power adjustment unit.

[0024] Exemplarily, in the low-temperature stage (temperature ≤ 300 °C), the system preferentially activates the electric heating. Each temperature zone dynamically adjusts the output power according to the temperature data fed back by the N-type thermocouple 41 through the PID algorithm. For example, when the actual temperature of a certain 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 the steady-state deviation; if the temperature difference exceeds ±10 °C, an alarm is triggered and the temperature rise is paused. The zoning design of the electric heater 22 combined with the closed-loop feedback mechanism can stabilize the local temperature control accuracy within ±3 °C and the overall uniformity within ±5 °C, which is especially suitable for the heat treatment of the Nb3Sn superconducting coil 7 that is sensitive to thermal stress.

[0025] It can be understood that the electric heating system works in coordination with the gas heating in the high-temperature stage, and further improves the anti-interference ability of the system by dynamically compensating for the gas power fluctuation (for example, when the gas suddenly increases and causes local overheating, the electric heating power automatically decreases).

[0026] (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 gas flow distribution in the furnace and eliminate the temperature gradient. Specifically, the stirring fan 32 is installed on the top of the heating furnace body 8 and is rotationally connected to the centrifugal impeller 34 through the stirring shaft 33, and then adjusts the speed according to the instruction of the temperature analysis feedback module 51.

[0027] Exemplarily, when it is detected that the deviation between the highest temperature of the coil and the target value exceeds 5 °C, the fan speed increases linearly (for every 2 °C increase in temperature difference, the speed increases by 10%), forcing the gas flow to circulate along the diversion channel, and focusing on enhancing the heat transfer efficiency in the low-temperature area. It can be understood that the fan system and the gas-electric heating subsystem are linked and started synchronously in the heat preservation stage. By enhancing the convective heat transfer, the influence of thermal inertia is reduced, and the temperature uniformity in the furnace is improved to within ±3 °C. This intelligent speed control mechanism not only shortens the temperature balance time but also reduces the fan energy consumption, which is suitable for long-cycle and high-uniformity heat treatment processes.

[0028] (4) Temperature acquisition subsystem 4: Consists of a high-precision thermocouple 41 network, including two types of temperature sensors, namely furnace body thermocouples and workpiece thermocouples. Specifically, the furnace body thermocouples are evenly distributed on the inner wall of the vacuum crucible 6, arranged circumferentially at equal angles along the longitudinal vertical center line (for example, one group is arranged every 30 - 60°), and the surface temperature of each area of the inner wall of the crucible is monitored in real time; correspondingly, the workpiece thermocouples are directly set inside the superconducting coil 7 and are distributed at equal intervals along the axial direction of the coil (for example, one group is arranged every 30 - 60°), accurately feedbacking the temperature field distribution of the coil body.

[0029] Exemplarily, all the signals of the thermocouples 41 are transmitted to the industrial computer acquisition system through shielded cables, and the sampling frequency reaches 10 Hz to ensure data real-time performance. During the heating-up stage, by comparing the data of the furnace body thermocouple and the workpiece thermocouple (such as the crucible temperature of 320 °C - the coil temperature of 305 °C), the heating strategy is dynamically corrected to avoid temperature control deviation caused by heat conduction delay. It can be understood that the dual-sensor redundancy design further improves the reliability. When a certain sensor fails, the system automatically switches to the backup signal and triggers a maintenance alarm to ensure process continuity.

[0030] (5) Temperature analysis and feedback subsystem 5: As the control center, the temperature analysis and feedback module 51 runs temperature control algorithms (such as PID temperature control algorithms, 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 data transmission lines to achieve real-time communication, and then constructs a hierarchical closed-loop control system.

[0031] It can be understood that the superconducting coil 7 is placed inside the vacuum crucible 6. The outer wall of the crucible is surrounded by electric heaters 22, the inner wall of the heating furnace body 8 is arranged with gas nozzles 12, and a stirring fan 32 is installed at the top to form an "electric-gas-wind" three-in-one heating and temperature equalization system: In the low-temperature stage, the electric heating system, relying on its ability to control temperature in zones with PID, accurately runs the temperature control process curve; when the temperature breaks through the 300 °C threshold, the gas system intervenes. Through the coordinated combustion of multi-zone nozzles, it supplements the high-power demand, and at the same time, through the forced circulation of the air flow by the fan, the temperature field is balanced, which can effectively eliminate the axial temperature gradient and improve the temperature control accuracy of the local and overall areas, effectively meeting the high-standard heat treatment requirements of the large superconducting coil 7 of the nuclear fusion device.

[0032] Refer to Figures 2 - 5 , the present invention also provides an embodiment of a method for controlling the heat treatment temperature of the superconducting coil 7 of the nuclear fusion device, which is executed by the heat treatment temperature control system of the superconducting coil 7 of the nuclear fusion device as described in the above embodiment. The temperature control method includes: S100, input the user target temperature curve and the uniform heating parameter process of the heat treatment; S200, perform the electric heating zone temperature control process in the low-temperature stage of the heat treatment, and detect and judge in real time whether to switch to the heating-up or heat preservation process; S300, perform the gas heating and electric heating zone coordinated temperature control process in the high-temperature stage of the heat treatment, and detect and judge in real time whether to switch to the heating-up or heat preservation process and the temperature equalization process.

[0033] Exemplarily, when setting the heat treatment user target temperature curve and the uniform heating parameter process, a preset temperature process curve is imported. This curve includes key parameters such as the heating rate, holding temperature, and holding time. At the same time, the temperature uniformity requirement is set, and then these parameters will be automatically analyzed and a corresponding feedback control scheme will be generated; during the electric heating zone temperature control process in the heat treatment heating stage and the gas heating and electric heating zone coordinated temperature control process in the heat treatment holding stage, the temperature uniformity is ensured to be always maintained within the range required by the process through multi-system coordinated control. This method effectively solves the problems of temperature uniformity and temperature control accuracy in the heat treatment process of large superconducting coils 7 through intelligent hierarchical temperature control and multi-system dynamic coordination.

[0034] Please continue to refer to Figure 3 , in this embodiment, S100 includes: S110, import or input the target process temperature curve through the input interface, and set the temperature uniformity parameters; S120, analyze the temperature curve and the temperature uniformity parameters, and generate a feedback control scheme for the heat treatment adjustment process.

[0035] Exemplarily, in the initial configuration stage of the heat treatment process, the operator can select to import a pre-stored standardized process temperature curve template through the human-machine interface (HMI) of the industrial control computer or a dedicated control software, or manually input customized temperature control parameters according to the specific requirements of the current workpiece to be processed. Specifically, these parameters include but are not limited to: initial temperature, multi-stage heating rates (such as 50°C / h to 300°C stage, 100°C / h to 650°C stage, etc.), target temperature values of each holding platform (such as 300°C, 450°C, 650°C, etc.) and corresponding holding durations, maximum allowable cooling rates and other key process indicators; at the same time, temperature uniformity control parameters need to be set, including the maximum temperature difference range allowed on the workpiece surface (such as ±5°C), uniformity tolerances in different temperature ranges (such as ±8°C below 300°C, ±5°C above 300°C, etc.); then the system will perform format verification and logical checks on the input parameters to ensure the continuity and executability of the process curve.

[0036] 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 processed (such as diameter 5m, weight 8 tons, etc.) and material characteristics (such as the heat capacity and thermal conductivity of Nb3Sn, etc.), the optimal temperature adjustment strategy is automatically analyzed and calculated, and finally a feedback control scheme for the heat treatment adjustment process including control parameters such as the electric heating power distribution scheme, the gas intervention timing, and the fan speed adjustment strategy is generated.

[0037] Please continue to refer to Figure 4 , in this embodiment, S200 includes: S210, Self-check the working status of the thermocouples 41 in all temperature control zones, and read the first process temperature curve; S220, Real-time detect the temperature values of the heating furnace body 8 and the superconducting coil 7 fed back by the thermocouples 41 in all temperature control zones, and analyze the current temperature change trend; S230, Based on the feedback control scheme of the heat treatment adjustment process, convert it into a control instruction sequence of the first target preset working condition parameters, and send a status switching signal control signal to adjust the heating working condition parameters of the electric heater 22; S240, The electric heater 22 runs the heating or heat preservation process based on the heating state or heat preservation state switching signal, and the stirring fan 32 runs the temperature equalization process based on the temperature based on the heating state or heat preservation state switching signal.

[0038] Exemplarily, in the electric heating zone temperature control process during the heat treatment heating stage, first execute the self-check program to comprehensively detect the status of multiple groups of N-type thermocouples 41 distributed at corresponding positions of the vacuum crucible 6 and the superconducting coil 7, 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°C); at the same time, call the pre-set first process temperature curve from the process database, which details the heating gradient from room temperature to 300°C (such as 50°C / h in the 0-200°C interval and 30°C / h in the 200-300°C interval) and the holding time requirements for each temperature node; after confirming that all thermocouples 41 are working properly, synchronously obtain the internal environment temperature of the furnace body and the surface temperature data of the superconducting coil 7 fed back by the thermocouples 41 in each zone, and calculate the working condition operation parameters such as the temperature rise rate, maximum temperature difference, and temperature distribution standard deviation in each zone in real time. When it is detected that the temperature rise rate of a certain zone deviates from the set value by more than 15% or the temperature difference between adjacent zones exceeds 20°C, the system will trigger an early warning mechanism.

[0039] It should be noted in detail that the control instruction sequence of the first target preset working condition parameters includes: Real-time detect the actual temperature of each temperature control zone of the heating furnace body 8 and the superconducting coil 7, and compare it with the preset target temperature value of the first process temperature curve in real time; When the difference between the actual temperature change curve and the target temperature of the process curve is greater than the first temperature range, automatically switch from the heating state to the heat preservation state, and adjust the output power working condition parameters of the electric heater 22 by the PID control algorithm; When the difference between the actual temperature change curve and the target temperature of the process curve is less than the second temperature range, continue to run the current heating process; 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 value, and the absolute value of the difference increases, increase the rotation speed of the stirring fan 32.

[0040] Exemplarily, based on the above real-time monitoring data, the system will dynamically generate a control instruction sequence for the first target preset operating condition parameters according to the pre-generated feedback control scheme for the heat treatment adjustment process. Specifically, the core control logic of this instruction sequence includes: 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; 2) When the deviation between the actual temperature and the target value in any zone is detected to exceed the first temperature range (for example, greater than ±10°C), the system immediately interrupts the preset heating program and automatically switches to the heat preservation control mode. At this time, the temperature adjustment algorithm will start a three-level response mechanism: First, quickly adjust the output power of the electric heater 22 in this zone through a fuzzy PID controller (for example, the proportional coefficient Kp = 0.8, the integral time Ti = 120s, and the differential time Td = 20s) (for example, the adjustment range is 5% - 20%), and at the same time, link the heating elements in the adjacent 2 zones for collaborative compensation (for example, the power adjustment range is 50% of the abnormal zone); 3) When the system detects that the temperature deviation in all zones has dropped back within the second temperature range (for example, ±5°C) and remains stable for more than 1 sampling period (for example, 30s), automatically resume the original heating process to ensure that there will be no power mutation (for example, the single adjustment range < 25%) or over-temperature risk (for example, the maximum temperature < the material's ultimate temperature resistance).

[0041] Please continue to refer to Figure 5 , in this embodiment, S300 includes: S310, self-check the working status of the gas nozzles 12 in all temperature control zones and read the second process temperature curve; S320, real-time detect the temperature values of the heating furnace body 8 and the superconducting coil 7 fed back by the thermocouples 41 in all temperature control zones and analyze the current temperature change trend; S330, based on the feedback control scheme for the heat treatment adjustment process, convert it into a control instruction sequence for the second target preset operating condition parameters, and send a status switching signal control signal to adjust the heating condition parameters of the electric heater 22, the gas nozzle 12, and the stirring fan 32; S340, the electric heater 22 and the gas nozzle 12 operate the heating or heat preservation process based on the heating state or heat preservation state switching signal, and the stirring fan 32 operates the temperature equalization process based on the heating state or heat preservation state switching signal.

[0042] Exemplarily, in the gas-electric heating collaborative temperature control process during the heat treatment holding stage, first, the gas system self-check program is executed to detect the status of the gas nozzles 12 in multiple temperature control zones distributed at corresponding positions of the heating furnace body 8, including solenoid valve response time test (e.g., response time < 500 ms), air-fuel ratio valve opening calibration (e.g., opening error < ±2%), gas pressure monitoring (e.g., maintained at 0.25 ± 0.05 MPa), etc.; at the same time, the second process temperature curve is retrieved from the process database, and this curve details the heating rate (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 during the 650 °C holding stage needs to be controlled within ±3 °C) from 300 °C to the final temperature (such as 650 °C).

[0043] After entering the real-time monitoring stage, through the distributed temperature acquisition network composed of thermocouples 41, the real-time temperatures of different temperature control zones in the heating furnace body 8 and the vacuum crucible 6 are collected, 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 identifies abnormal temperature characteristics (such as the sudden change in the temperature rise rate in a certain area is greater than 10 °C / min or the temperature difference between adjacent nozzles is greater than 25 °C), the diagnostic subroutine is immediately started to locate the potential fault source.

[0044] It should be elaborated in detail that the second target preset working condition parameter temperature control instruction sequence includes: Real-time detect the actual temperatures of each temperature control zone of the heating furnace body 8 and the superconducting coil 7, and compare them with the preset target temperature values of the second process temperature curve in real time; 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, automatically switch from the heating state to the holding state, and adjust the output power working condition parameters of the PID control algorithm electric heater 22; 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, continue to run the current heating process; 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 value, and the absolute value of the difference increases, increase the rotation speed of the stirring fan 32.

[0045] Exemplarily, based on the real-time analysis results, a second target preset working condition parameter temperature control instruction sequence is generated, and this sequence contains multi-level control strategies: 1) Temperature-power closed-loop regulation: When the deviation between the actual temperature and the target value detected in any temperature control zone exceeds the first preset value (for example, > +3°C), a gradient power reduction strategy is executed. First, reduce the electric heating power in the corresponding zone (step size 10% per time), and at the same time adjust the air-fuel ratio of the gas nozzle 12 (0.5% step adjustment), and start the compensation heating of the adjacent 2 zones; when the temperature difference shrinks within the second preset value (for example, < -3°C), a gradient power increase strategy is executed. First, increase the electric heating power in the corresponding zone (step size 10% per time), and at the same time adjust the air-fuel ratio of the gas nozzle 12 (0.5% step adjustment), and turn off the compensation heating of the adjacent 2 zones. 2) Dynamic wind field regulation: Calculate in real time the deviation ΔT between the highest / lowest temperature on the coil surface and the set value. When the absolute value of the difference between the highest or lowest temperature of the coil and the user's target temperature is less than the target requirement value (for example, ±5°C), adjust the fan speed in grades according to the change rate (basic speed 800 rpm, and an increase of 100 rpm corresponds to a change amount of 0.5°C / min).

[0046] Through the above technical solutions, the present application uses the electric heating system in the low-temperature stage, giving full play to its high-precision temperature control ability and avoiding temperature fluctuations caused by premature gas intervention; in the high-temperature stage, gas heating is introduced to supplement the high-power demand, taking advantage of the high energy density characteristics of gas combustion, significantly reducing the peak power load. At the same time, by dynamically distributing the power ratio of gas and electric heating, the maximization of energy utilization efficiency is achieved, which is applicable to 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 combines the dynamic adjustment of the stirring fan 32 speed and the complementarity of gas-electric power to form a closed-loop feedback chain from local to overall, effectively improving the response speed and stability, and is applicable to the heat treatment process of superconducting coils 7 with long cycles and high uniformity requirements.

[0047] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A heat treatment temperature control system for a nuclear fusion superconducting coil, characterized in that, Comprising: A gas heating control subsystem, including a gas power control module, which is used to control the heating and heat preservation condition parameters of the gas nozzle; An electric heating control subsystem, including an electric heating power control module, which is used to control the heating and heat preservation condition parameters of the electric heater; An air velocity control subsystem, including a fan speed control module, which is used to control the speed condition parameters of the stirring fan; A temperature acquisition subsystem, including a thermocouple, which is used to acquire the temperature condition parameters of the vacuum crucible and the superconducting coil; A temperature analysis and feedback subsystem, including 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 the target preset condition parameters and generate a heat treatment adjustment process feedback control scheme.

2. The heat treatment temperature control system for the nuclear fusion superconducting coil according to claim 1, wherein The superconducting coil is placed inside the vacuum crucible. The inner wall of the vacuum crucible is annularly provided with an electric heater. A heating furnace body is arranged outside the vacuum crucible. The inner wall of the heating furnace body is annularly provided with gas nozzles. A stirring fan is installed on the top of the heating furnace body. The stirring fan is rotationally connected to a centrifugal impeller through a stirring shaft.

3. The heat treatment temperature control system of the nuclear fusion superconducting coil according to claim 2, wherein The gas nozzle includes a top zone nozzle, a middle zone nozzle and a bottom zone nozzle, which divide the heating furnace body into a top zone, a middle zone and a bottom zone. The gas nozzles are symmetrically distributed along the longitudinal vertical central section of the heating furnace body. The gas nozzle is connected with 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.

4. The heat treatment temperature control system for the nuclear fusion superconducting coil according to claim 1, wherein The thermocouple includes a furnace body thermocouple and a workpiece thermocouple. The furnace body thermocouple is arranged on the inner wall of the vacuum crucible and is annularly arranged at equal angles along the longitudinal vertical center of the heating furnace body. The workpiece thermocouple is arranged on the superconducting coil and is annularly arranged at equal angles along the longitudinal vertical center of the superconducting coil.

5. A method for controlling the heat treatment temperature of a nuclear fusion superconducting coil, characterized in that, The temperature control method is executed by the nuclear fusion superconducting coil heat treatment temperature control system according to any one of claims 1 to 4. The temperature control method includes: S100, inputting a heat treatment user target temperature curve and a uniform heating parameter process; S200, performing an electric heating zone temperature control process in the low-temperature stage of heat treatment, and real-time detecting and judging whether to switch to a heating or heat preservation process; S300, performing a gas heating and electric heating zone collaborative temperature control process in the high-temperature stage of heat treatment, and real-time detecting and judging whether to switch to a heating or heat preservation process and a temperature equalization process.

6. The heat treatment temperature control method for the nuclear fusion superconducting coil according to claim 5, 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 heat treatment adjustment process feedback control scheme.

7. The heat treatment temperature control method for the nuclear fusion superconducting coil according to claim 5, wherein, The S200 includes: S210, self-checking the working state of all temperature control zone thermocouples and reading the first process temperature curve; S220, real-time detecting the temperature values of the heating furnace body and the superconducting coil fed back by all temperature control zone thermocouples, and analyzing the current temperature change trend; S230, based on the feedback control scheme of the heat treatment adjustment process, convert it into a control instruction sequence for the first target preset working condition parameters, and send a status switching signal control signal to adjust the heating working condition parameters of the electric heater; S240, the electric heater operates the heating or heat preservation process based on the heating state or heat preservation state switching signal, and the stirring fan operates the temperature equalization process based on the temperature based on the heating state or heat preservation state switching signal.

8. The heat treatment temperature control method for the nuclear fusion superconducting coil according to claim 7, characterized in that, The first target preset working condition parameter control instruction sequence includes: Real-time detect the actual temperature of each temperature control zone of the heating furnace body and the superconducting coil, and compare it with the preset target temperature value of the first process temperature curve in real time; When the difference between the actual temperature change curve and the target temperature of the process curve is greater than the first temperature range, automatically switch from the heating state to the heat preservation state, and adjust the output power working condition parameters of the electric heater by the PID control algorithm; When the difference between the actual temperature change curve and the target temperature of the process curve is less than the second temperature range, continue to run the current heating process; 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 value, and the absolute value of the difference increases, increase the rotation speed of the stirring fan.

9. The heat treatment temperature control method of the nuclear fusion superconducting coil according to claim 5, characterized in that, The S300 includes: S310, self-check the working status of the gas nozzles in all temperature control zones, and read the second process temperature curve; S320, real-time detect the temperature values of the heating furnace body and the superconducting coil fed back by the thermocouples in all temperature control zones, and analyze the current temperature change trend; S330, based on the feedback control scheme of the heat treatment adjustment process, convert it into a control instruction sequence for the second target preset working condition parameters, and send a status switching signal control signal to adjust the heating working condition parameters of the electric heater, gas nozzle and stirring fan; S340, the electric heater and the gas nozzle operate the heating or heat preservation process based on the heating state or heat preservation state switching signal, and the stirring fan operates the temperature equalization process based on the temperature based on the heating state or heat preservation state switching signal.

10. The heat treatment temperature control method for the nuclear fusion superconducting coil according to claim 9, characterized in that, The second target preset working condition parameter control instruction sequence includes: Real-time detect the actual temperature of each temperature control zone of the heating furnace body and the superconducting coil, and compare it with the preset target temperature value of the second process temperature curve in real time; 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, automatically switch from the heating state to the heat preservation state, and adjust the output power working condition parameters of the electric heater by the PID control algorithm; 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, continue to run the current heating process; 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 value, and the absolute value of the difference increases, increase the rotation speed of the stirring fan.

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