Multi-stage speed intelligent temperature control type induction heating device

Abstract

This invention belongs to the field of temperature-controlled induction heating technology, specifically a multi-segment intelligent temperature-controlled induction heating device. The proposed solution includes an electromagnetic coil and a first temperature measuring instrument located at the tail end of the electromagnetic coil. Three sets of electromagnetic coils are configured: a preheating coil, a through-heating coil, and a soaking coil. Gaps are left between the preheating coil, through-heating coil, and soaking coil. A second, third, and fourth temperature measuring instrument are respectively installed at the beginning of each of the preheating coil, through-heating coil, and soaking coil. A central controller is also included. This invention, by employing a three-segment axially spaced layout of the preheating coil, through-heating coil, and soaking coil, fundamentally reduces the surface temperature difference and thermal stress caused by rapid heating. Based on the total adjustment calculated from the final temperature deviation, intelligent dynamic redistribution is performed according to the efficiency of each coil, giving the system strong adaptive fault tolerance and effectively improving the uniformity and effectiveness of heating.

Description

Technical Field

[0001] This invention relates to the field of temperature-controlled induction heating technology, and more particularly to a multi-speed intelligent temperature-controlled induction heating device. Background Technology

[0002] In fields such as oil extraction and machinery manufacturing, heat treatment (quenching + high-temperature tempering) is a key process for improving the strength, toughness and service life of long shaft metal workpieces such as sucker rods and drill pipes. Electromagnetic induction heating is usually used.

[0003] However, existing induction heating tempering equipment typically uses a single induction coil to heat continuously passing workpieces in a single operation. Due to the inherent "skin effect" of induction heating, rapid heating can easily lead to an excessive temperature difference between the workpiece surface and core, generating huge thermal stress, which can cause workpiece deformation or even cracking, seriously affecting product quality. Summary of the Invention

[0004] Based on the technical problems in the background technology, the present invention proposes a multi-speed intelligent temperature control induction heating device.

[0005] This invention proposes a multi-segment speed intelligent temperature control induction heating device, comprising an electromagnetic coil and a first temperature measuring instrument located at the tail end of the electromagnetic coil. The electromagnetic coil is configured with three sets: a preheating coil, a through-heating coil, and a heat-spreading coil, with gaps between them. A second, third, and fourth temperature measuring instrument are respectively installed at the head ends of the preheating coil, through-heating coil, and heat-spreading coil. The device also includes a central controller, which is connected to the heating power supply of the preheating coil, through-heating coil, and heat-spreading coil, the first, second, third, and fourth temperature measuring instruments, and an encoder signal for monitoring the workpiece conveying speed.

[0006] The central controller is configured as follows:

[0007] A. Synchronously collect temperature data from each thermometer, speed data from the encoder, and operating status data from each heating power source;

[0008] B. Based on the deviation between the final outlet temperature and the target temperature, and combined with the real-time operating performance evaluation results of each coil, generate and dynamically allocate the temperature adjustment amount to each coil to determine the real-time temperature setpoint of each coil.

[0009] C. For each coil, the power command to drive its heating is calculated based on its real-time temperature setpoint, speed data, inlet temperature and heating power supply status.

[0010] Preferably, in step B, the performance evaluation specifically involves: for each electromagnetic coil, using a preset thermodynamic feedforward coefficient, real-time speed data, and the difference between the previous dynamic temperature setpoint and the current inlet temperature, estimating the theoretical power requirement required to heat the workpiece section; then comparing the theoretical power requirement with the actual electrical power input fed back in real time by the heating power supply corresponding to the coil, to obtain a performance factor characterizing the current energy conversion efficiency of the coil.

[0011] Preferably, in step B, the dynamic allocation method of the temperature adjustment amount is as follows: the real-time efficiency factor of each coil is used as part of the weight for proportional allocation, and the coil with the higher efficiency factor receives a larger adjustment amount. The final adjustment amount is then determined by combining the preset fixed allocation coefficient.

[0012] Preferably, in step C, the power command is calculated as follows: the feedforward power term is calculated based on the real-time temperature setpoint, speed, and inlet temperature; the feedback power term is calculated based on the deviation between the real-time temperature setpoint and the outlet temperature using the feedback controller; the compensation power term is calculated based on whether the current of the heating power supply and the device temperature exceed the safety threshold; and the feedforward, feedback, and compensation power terms are added together to obtain the final power command.

[0013] Preferably, the calculation of the compensation power term includes: when the output current of the heating power supply exceeds the safe current threshold, generating a negative current compensation value based on the magnitude of the excess; when the temperature of the key components inside the power supply exceeds the safe temperature threshold, generating a negative temperature compensation value based on the magnitude of the excess; the compensation power term is the sum of the current compensation value and the temperature compensation value.

[0014] Preferably, the first, second, third, and fourth thermometers are all located above the electromagnetic coil, and each of the first, second, third, and fourth thermometers is connected to an electric guide rail, which carries the first, second, third, and fourth thermometers to reciprocate in the radial direction of the electromagnetic coil.

[0015] Preferably, both ends of the third and fourth thermometers are provided with vertically extending shielding boxes, the shielding boxes correspond to the gaps between adjacent electromagnetic coils, the end face of the shielding box facing the gap is set in a V-shaped structure, the two inclined surfaces of the V-shaped structure face the electromagnetic coils, a mounting base is fixed between the bottom of the shielding box and the frame, a connecting pipe for air extraction is provided inside the shielding box, a fan is connected to the top of the connecting pipe, and multiple vertically distributed air pipes are provided on the two inclined surfaces of the V-shaped structure, and the air pipes are connected to the connecting pipe.

[0016] The central controller is also connected to the exhaust fan signal and is further configured to perform the following controls:

[0017] D. Determine the desired temperature of the gap region based on the real-time temperature setpoints and working efficiency of the coils on both sides of the gap;

[0018] E. Adjust the exhaust fan intensity based on the deviation between the desired temperature and the actual average temperature measured by the temperature sensor;

[0019] F. A comprehensive health index is generated based on gap temperature uniformity, workpiece surface temperature uniformity, normalized energy efficiency ratio, and coil current imbalance, which is used for equipment early warning and fault location.

[0020] Preferably, in step D, the desired temperature is determined by: calculating the average value of the real-time temperature setpoints of the two coils as a basis, and then weighting and correcting the base value according to the working efficiency of the two coils.

[0021] Preferably, in step F, the comprehensive health index is generated by normalizing four characteristic parameters: gap temperature uniformity, workpiece surface temperature uniformity, normalized energy efficiency ratio, and current imbalance, and then performing a weighted summation.

[0022] The beneficial effects of this invention are as follows:

[0023] 1. In this invention, by adopting a three-segment axially spaced layout of preheating coil, through-heating coil, and heat-spreading coil, the temperature difference and thermal stress caused by rapid heating are fundamentally reduced. The total adjustment amount calculated based on the final temperature deviation is intelligently and dynamically redistributed according to the efficiency of each coil. The coil with higher efficiency assumes more control responsibility, thereby automatically compensating for the performance degradation caused by coil aging, decreased cooling efficiency, etc., giving the system a strong adaptive fault tolerance capability and effectively improving the uniformity and effectiveness of heating.

[0024] 2. In this invention, a shielding box with a V-shaped slope and air extraction function is set at the coil gap to ensure the high uniformity and stability of the axial temperature of long shaft workpieces during continuous movement. It also constructs a health characteristic system with four dimensions: gap temperature uniformity, surface heating uniformity, normalized region energy efficiency ratio, and current imbalance, which greatly reduces unplanned downtime and maintenance costs. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of a multi-segment speed intelligent temperature control induction heating device proposed in this invention.

[0026] Figure 2 This is a schematic diagram of the coil distribution structure of a multi-segment speed intelligent temperature control induction heating device proposed in this invention;

[0027] Figure 3 This is a schematic diagram of the electric guide rail position structure of a multi-speed intelligent temperature control induction heating device proposed in this invention.

[0028] Figure 4 This is a schematic diagram of the shielding box structure of a multi-speed intelligent temperature control induction heating device proposed in this invention;

[0029] Figure 5 This is a flowchart illustrating the intelligent conditioning and heating control process of a multi-segment speed intelligent temperature control induction heating device proposed in this invention.

[0030] Figure 6 This is a flowchart illustrating the intermittent thermal management and predictive diagnostics of a multi-segment speed intelligent temperature-controlled induction heating device proposed in this invention.

[0031] In the diagram: 1. Frame, 2. Preheating coil, 3. Through-heating coil, 4. Heat dissipation coil, 5. First temperature measuring instrument, 6. Second temperature measuring instrument, 7. Third temperature measuring instrument, 8. Fourth temperature measuring instrument, 9. Electric guide rail, 10. Shielding box, 11. Mounting base, 12. Connecting pipe, 13. Air pipe. Detailed Implementation

[0032] Example 1: Refer to Figures 1-4 A multi-segment speed intelligent temperature control induction heating device includes an electromagnetic coil mounted on a frame 1 and a first thermometer 5 located at the tail end of the electromagnetic coil. The electromagnetic coil is provided in three sets, namely a preheating coil 2, a through-heating coil 3, and a heat-spreading coil 4. The preheating coil 2, through-heating coil 3, and heat-spreading coil 4 are evenly distributed from the beginning to the end. The first thermometer 5 is located at the end of the heat-spreading coil 4 away from the through-heating coil 3. There is a gap between the preheating coil 2, through-heating coil 3, and heat-spreading coil 4. A second thermometer 6, a third thermometer 7, and a fourth thermometer 8 are respectively provided at the beginning ends of the preheating coil 2, through-heating coil 3, and heat-spreading coil 4. The first thermometer 5, the second thermometer 6, the third thermometer 7, and the fourth thermometer 8 are all non-contact infrared thermometers.

[0033] It also includes a central controller, which is connected to the heating power supplies of the preheating coil 2, the through-heating coil 3, and the heat spreader coil 4, as well as the first temperature measuring instrument 5, the second temperature measuring instrument 6, the third temperature measuring instrument 7, the fourth temperature measuring instrument 8, and an encoder signal used to monitor the workpiece conveying speed. The three sets of coils for preheating, through-heating, and heat spreader are each driven by three independent medium-frequency induction heating power supplies. Each power supply has communication capabilities and can provide real-time feedback to the central controller on its output power, output current, and the temperature status data of key internal power devices.

[0034] The central controller is configured as follows:

[0035] A. Synchronously collect temperature data from each thermometer, speed data from the encoder, and operating status data from each heating power source, and filter the data.

[0036] B. Based on the deviation between the final outlet temperature and the target temperature, and combined with the real-time operating performance evaluation results of each coil, generate and dynamically allocate the temperature adjustment amount to each coil to determine the real-time temperature setpoint of each coil.

[0037] The work efficiency evaluation is as follows: For each electromagnetic coil, the theoretical power requirement for heating the workpiece section is estimated by using the preset thermodynamic feedforward coefficient, real-time speed data, and the difference between the dynamic temperature setpoint of the coil at the previous moment and the current inlet temperature; then the theoretical power requirement is compared with the actual electrical power input fed back in real time by the heating power supply corresponding to the coil to obtain the efficiency factor characterizing the current energy conversion efficiency of the coil, wherein the efficiency factor is normalized to a predetermined numerical range;

[0038] The dynamic allocation method of temperature adjustment is as follows: the real-time efficiency factor of each coil is used as part of the weight for proportional allocation. Coils with higher efficiency factors receive a larger adjustment amount, and the final adjustment amount is determined by combining the preset fixed allocation coefficient.

[0039] C. For each coil, based on its own real-time temperature setpoint, speed data, inlet temperature and heating power supply status, calculate the power command to drive its heating.

[0040] The power command is calculated as follows: the feedforward power term is calculated based on the real-time temperature setpoint, speed, and inlet temperature; the feedback power term is calculated based on the deviation between the real-time temperature setpoint and the outlet temperature through the feedback controller; the compensation power term is calculated based on whether the current of the heating power supply and the device temperature exceed the safety threshold; and the feedforward, feedback, and compensation power terms are added together to obtain the final power command.

[0041] Specifically:

[0042] Step 1: Synchronous Data Acquisition and Standardized Processing Across the Entire Data Chain

[0043] 1. Temperature signal acquisition and conversion: The analog input module reads the 4-20mA current signals from four thermometers; according to the preset range (e.g., 0-1200℃), the signals are linearly converted to obtain four temperature values: T5 (final temperature), T6 (initial temperature), T7 (temperature after preheating), and T8 (temperature after heat penetration).

[0044] 2. Speed ​​signal acquisition and calculation: Read the number of encoder pulses accumulated by the high-speed counting module in the previous cycle. The number of pulses per encoder revolution is known. and roller conveyor circumference According to the formula Calculate real-time linear velocity .in To control the cycle;

[0045] 3. Equipment Status Data Acquisition: Real-time data packets are read from the three heating power supplies via industrial Ethernet or fieldbus, and the preheating coil power supply status is obtained through parsing. , , The power supply of the incandescent coil , , The power supply of the heat spreader coil , , ; Represents active power. Represents the output current. This represents the temperature of key components.

[0046] Step 2: Intelligent decision-making for dynamic temperature setpoints based on equipment performance evaluation:

[0047] 1. Online evaluation of the real-time performance factor H of each coil:

[0048] 1.1 Theoretical heat demand calculation: The core of performance evaluation is to compare "expected energy consumption with actual energy consumption";

[0049] Taking a preheating coil as an example, the system needs to calculate the theoretical heat required to heat a section of workpiece from the inlet temperature to the target temperature;

[0050] First, it is necessary to determine the fixed period. Inside, the workpiece mass passing through the preheating coil , ,in For the density of the workpiece, For cross-sectional area, For speed;

[0051] Secondly, calculate the heat required for the theoretical temperature rise of this section of the workpiece. ,

[0052] ,in The specific heat capacity of the workpiece. This is the set value from the previous cycle. To achieve the target temperature rise;

[0053] To facilitate comparison with electrical power, heat is... Converted to theoretical average power , ;according to And substitution The formula yields the following;

[0054] make It combines the physical properties of the workpiece with the heating efficiency of the coil segment, namely the thermodynamic feedforward coefficient, which can be obtained by process calculation or system identification.

[0055] Therefore, the theoretical power demand formula simplifies to:

[0056] .

[0057] 1.2 Obtaining actual electrical power input: Directly read the active power value from the preheating coil power supply. .

[0058] 1.3 Calculation of Real-Time Performance Factor: Performance Factor Defined as the ratio of theoretical demand to actual input, it characterizes the efficiency of converting energy from electrical energy into workpiece thermal energy.

[0059] The calculation formula is: ;

[0060] in It is a very small positive number (such as 0.001) to prevent division by zero errors; This is a dimensionless number, ideally close to 1.0. If it consistently falls below 0.85, it strongly suggests a decrease in the efficiency of the preheating coil. Similarly, calculations... and .

[0061] In the induction heating control, an online quantitative assessment of the health and efficiency of the actuator (induction coil) is introduced, which can reflect the performance degradation of the coil caused by aging, poor cooling, and changes in inter-turn insulation in real time.

[0062] 2. Calculate the global deviation and the basic temperature adjustment:

[0063] 2.1 Final temperature deviation: ,in This is the preset process target temperature.

[0064] 2.2 Basic adjustment amount: Incremental digital PID algorithm is used;

[0065] First, calculate the proportional term. ,in For proportional gain, This is the deviation from the previous cycle;

[0066] Integral term , This is the integral gain;

[0067] Differential term , For differential gain, This represents the deviation from the first two cycles;

[0068] Base temperature adjustment The sum of the three: .

[0069] 3. Performance-weighted dynamic temperature setpoint generation:

[0070] 3.1 Dynamic weight calculation: The system calculates the dynamic weight of each coil based on its real-time performance, and the total weight is 1. The coil with higher performance has a larger weight.

[0071] For example, the dynamic weight of the preheating coil is .

[0072] 3.2 Adjustment of Quantity Allocation and Generation of Setpoints: Combined with preset fixed allocation coefficients ( (The sum is 1), calculate the final adjustment amount for each coil;

[0073] Preheating coil adjustment amount: ;

[0074] Similarly, the adjustment amount for the heating coil: ;

[0075] Adjustment amount of heat spreader coil: ;

[0076] Real-time temperature setpoints for each coil From the basic settings Adding the adjustment amount gives:

[0077] Preheating coil settings: .

[0078] Similarly, ;

[0079] .

[0080] By weighted allocation of efficiency, the control system acquires adaptive fault tolerance; even if the efficiency of a certain coil slowly declines, the system can automatically adjust the task allocation, allowing the healthy coils to take on more work, thereby maintaining the stability of the final process temperature during equipment performance fluctuations, which greatly improves the robustness and long-term reliability of the system.

[0081] Step 3: Synthesis and output of composite power command integrating multiple factors: For each coil, the central controller calculates three power components in parallel and synthesizes them into the final command;

[0082] 1. Calculation of feedforward power term FF: The feedforward term is used to directly respond to process requirements;

[0083] Taking the preheating coil as an example, its power command should be able to achieve the temperature rise set in the current cycle. ;

[0084] The calculation formula is similar to the theoretical heat demand, but uses the set value for the current cycle:

[0085] .

[0086] It achieves advanced compensation for major disturbances (speed changes, incoming material temperature fluctuations), making the system response speed several times faster than pure feedback control, and effectively suppressing temperature overshoot or undershoot caused by disturbances.

[0087] 2. Feedback power term FB calculation: The feedback term is used to correct errors and unknown disturbances in the feedforward model;

[0088] Calculate the actual temperature deviation at the outlet of this section: ;

[0089] Input this deviation into a PI controller specifically tuned for the preheating coil:

[0090] Proportional term: ;

[0091] Integral term: ,in This indicates the accumulation of historical deviations;

[0092] Feedback power term: .

[0093] This is used to eliminate the inaccuracies of the feedforward model and the steady-state errors caused by unmodeled disturbances, ensuring that the outlet temperature converges precisely to the set value.

[0094] 3. Equipment Status Compensation Power Item SC Calculation: This compensation item is designed to protect the equipment and prevent overload.

[0095] 3.1 Overcurrent Compensation When the current Exceeding the safety threshold When the rated current is 90%, the power is reduced proportionally.

[0096] The calculation formula is: ;in This is the current suppression coefficient; the negative sign indicates reduction.

[0097] 3.2 Overheat Compensation When the device temperature Exceeding the safety threshold (e.g., at 75℃) compensation is performed;

[0098] The calculation formula is: ;in This is the temperature compensation coefficient.

[0099] 3.3 Total Compensation Items: .

[0100] The compensation item of this invention performs "soft" power suppression as soon as the risk first appears, which can prevent equipment overload damage and ensure that the production process is not interrupted, thus achieving a balance between safety and production and improving equipment availability.

[0101] 4. Power Command Synthesis and Issuance: The final power command for the preheating coil. The sum of the three terms: ;

[0102] The controller sends this power command value to the heating power supply of the preheating coil via analog output or communication.

[0103] Induction coil ( ) and heat spreader coil ( The power commands are executed with exactly the same logic, substituting their respective parameters ( , T8, P2, I2 (etc.) to perform calculations and distribute.

[0104] Through the triple coordination of feedforward (rapid disturbance rejection), feedback (precise correction), and compensation (active safety protection), the power control of this invention achieves the best balance between speed, accuracy, and safety; it can not only cope with external process disturbances, but also adapt to changes in the state of internal equipment.

[0105] Example 2: Refer to Figures 1-4 A multi-speed intelligent temperature-controlled induction heating device, based on Embodiment 1, includes a first thermometer 5, a second thermometer 6, a third thermometer 7, and a fourth thermometer 8, all located above an electromagnetic coil. Each of these thermometers is connected to an electric guide rail 9. The electric guide rail 9 moves the thermometers 5, 6, 7, and 8 reciprocally in the radial direction of the electromagnetic coil. The electric guide rail 9 can be configured as a linear guide rail perpendicular to the extension direction of the rod, or it can be configured as an arc-shaped structure adapted to the electromagnetic coil. This reciprocating movement of the electric guide rail 9 allows for the calculation of the average temperature of the rod at different locations based on measurement data from different points, thereby improving the accuracy of measurement and corresponding control.

[0106] In this invention, both ends of the third thermometer 7 and the fourth thermometer 8 are provided with vertically extending shielding boxes 10. The shielding box 10 corresponds to the gap position between the adjacent electromagnetic coils. The end face of the shielding box 10 facing the gap is set into a V-shaped structure. Both sides of the V-shaped structure face the electromagnetic coils. The bottom of the shielding box 10 is fixed with a mounting base 11 between it and the frame 1. A connecting pipe 12 for air extraction is provided inside the shielding box 10. The top end of the connecting pipe 12 is connected to an exhaust fan. Both sides of the V-shaped structure are provided with multiple vertically distributed air pipes 13. The air pipes 13 are connected to the connecting pipe 12. The air extraction operation of the air pipes 13 on the V-shaped structure causes the temperature generated by the heating of the electromagnetic coils on both sides of the gap position to diffuse towards the gap position, thereby ensuring that the gap position can be accurately monitored while ensuring the heating stability of the rod.

[0107] In this invention, the central controller is also connected to the exhaust fan and temperature sensor. The temperature sensor is integrated on the V-shaped structure of the shield box 10, and multiple sensors are usually distributed vertically on both sides of the inclined surface to form a temperature sensor array. These sensors are directly exposed to the airflow environment of the gap area through the mounting point near the air pipe 13 to monitor the thermal environment of the gap area between the coils.

[0108] The central controller is further configured to perform the following controls:

[0109] D. Determine the desired temperature of the gap region based on the real-time temperature setpoints and working efficiency of the coils on both sides of the gap;

[0110] The desired temperature is determined by: calculating the average value of the real-time temperature setpoints of both coils as a basis, and then weighting and correcting the base value based on the working efficiency of both coils;

[0111] E. Adjust the exhaust fan intensity based on the deviation between the desired temperature and the actual average temperature measured by the temperature sensor;

[0112] F. A comprehensive health index is generated based on gap temperature uniformity, workpiece surface temperature uniformity, normalized energy efficiency ratio, and coil current imbalance, which is used for equipment early warning and fault location.

[0113] The comprehensive health index is generated by normalizing four characteristic parameters: gap temperature uniformity, workpiece surface temperature uniformity, normalized energy efficiency ratio, and current imbalance, and then summing them by weight.

[0114] Specifically:

[0115] Step 4: Active thermal environment equalization control in the gap region:

[0116] 1. Calculate the dynamic desired temperature of the gap. :

[0117] Taking the preheating-through gap as an example; first, calculate the basic expected value. That is, the midpoint between the target temperatures of the two coils: ;

[0118] Then, considering the impact of the actual efficiency of both coils on the heating contribution, if the efficiency of one side is low, its heating capacity will be reduced; therefore, an efficiency-weighted correction is applied to the base value:

[0119] .

[0120] in and These are preset weighting coefficients, and their sum is 1.

[0121] The desired temperature of the gap is no longer a fixed value, but is dynamically related to the process objectives and real-time performance of the adjacent coils. When the performance of one coil decreases, the system will rationally adjust the heating requirements for that gap area to avoid energy waste and unrealistic control targets, reflecting the intelligence of global energy management.

[0122] 2. Closed-loop regulation of exhaust fan speed:

[0123] 2.1 Calculate the actual average temperature of the gap based on the readings of N thermocouples inside the shielding box. : .

[0124] 2.2 Calculation of temperature deviation .

[0125] 2.3 Using a PI controller to adjust the fan speed :

[0126] Proportional term: ;

[0127] Integral term: ;

[0128] Final speed command: ;

[0129] The base rotational speed required to maintain minimum airflow.

[0130] Step 5: Predictive Health Diagnosis of Devices through Multi-Dimensional Feature Fusion

[0131] 1. Calculation of characteristic quantities:

[0132] 1.1 Gap temperature uniformity : Calculate all The standard deviation reflects whether the heat distribution within the gap is uniform.

[0133] The calculation formula is: .

[0134] 1.2 Temperature uniformity of workpiece surface : Use a temperature measuring instrument (such as the third temperature measuring instrument 7) mounted on the electric guide rail to scan along the radial direction of the workpiece. Points are used to obtain the temperature array. ;

[0135] Calculate its standard deviation: ,in This represents the average temperature during the scan.

[0136] 1.3 Normalized Regional Energy Efficiency Ratio This is a more purely reflective indicator of the "electricity-heat-environment" conversion efficiency;

[0137] Heat output (can be considered as temperature rise): ;in Ambient temperature;

[0138] Combined electrical input: Multiplying it by the efficiency factor is to offset the fluctuations in the power supply's own efficiency.

[0139] Normalization: To avoid the influence of absolute power values, a reference power is introduced. (e.g., 100kW) is normalized;

[0140] The calculation formula is: ;in It is a very small constant. It is a dimensionless ratio, and its decreasing trend may indicate that heat exchange is obstructed.

[0141] 1.4 Current imbalance : ; Calculate the degree of difference in current between two adjacent coils. An abnormal increase in this value is a sensitive indicator of coil faults (such as inter-turn short circuits); among which This is the rated current of the coil.

[0142] 2. Comprehensive Health Index (HI) Generation and Alarm Decision-Making:

[0143] 2.1 Feature normalization: Mapping four features of different dimensions to the interval [0,1];

[0144] For example, for Set an experience threshold (e.g., 10℃), normalized value ;

[0145] when hour, A value of 1 indicates the worst-case scenario;

[0146] The same applies to other features.

[0147] 2.2 Index Calculation: ;

[0148] in These are the weighting coefficients, and their sum is 1. Because The higher the level, the healthier, so we take the opposite approach.

[0149] 2.3 Decision-making and positioning:

[0150] Warning: When the 10-period moving average of HI... When the value exceeds 0.25, a "Health Warning for XX Interval Area" message will be displayed on the user interface.

[0151] Alarm and location: When the instantaneous HI value exceeds 0.5 or When the value exceeds 0.4, an advanced alarm is triggered;

[0152] System Analysis , , , The contribution percentage of the four sub-items in HI, if and The combined percentages exceeded 70%, and If the low-temperature zone found during the calculation is at a fixed angle in the scan data (such as the 4-8 o'clock direction), the system will generate a precise alarm message: "Fault location: Preheating-heating gap area, there is suspected inter-turn short circuit or severe poor cooling on the downstream side of the heat-transmitting coil (4-8 o'clock direction), it is recommended to check immediately."

[0153] The system can issue early warnings at the nascent stage of a fault (such as slight local overheating of the coil or slight blockage of the cooling water) and has the ability to accurately locate the fault point; significantly reducing maintenance costs and improving the overall efficiency of the equipment.

[0154] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A multi-speed intelligent temperature-controlled induction heating device, comprising an electromagnetic coil and a first temperature measuring instrument (5) located at the tail end of the electromagnetic coil, characterized in that, The electromagnetic coil is provided in three sets, namely a preheating coil (2), a through-heating coil (3), and a heat-spreading coil (4). There is a gap between the preheating coil (2), the through-heating coil (3), and the heat-spreading coil (4). A second thermometer (6), a third thermometer (7), and a fourth thermometer (8) are respectively provided at the beginning of the preheating coil (2), the through-heating coil (3), and the heat-spreading coil (4). It also includes a central controller, which is connected to the heating power supply of the preheating coil (2), the heat transmission coil (3), the heat dissipation coil (4), the first temperature measuring instrument (5), the second temperature measuring instrument (6), the third temperature measuring instrument (7), the fourth temperature measuring instrument (8), and the encoder signal used to monitor the workpiece conveying speed. The central controller performs the following steps: A. Synchronously collect temperature data from each thermometer, speed data from the encoder, and operating status data from each heating power source; B. Based on the deviation between the final outlet temperature and the target temperature, and combined with the real-time operating performance evaluation results of each coil, generate and dynamically allocate the temperature adjustment amount to each coil to determine the real-time temperature setpoint of each coil. C. For each coil, based on its own real-time temperature setpoint, speed data, inlet temperature and heating power supply status, calculate the power command to drive its heating. The first thermometer (5), the second thermometer (6), the third thermometer (7), and the fourth thermometer (8) are all located above the electromagnetic coil, and each of the first thermometer (5), the second thermometer (6), the third thermometer (7), and the fourth thermometer (8) is connected to an electric guide rail (9). The electric guide rail (9) moves the first thermometer (5), the second thermometer (6), the third thermometer (7), and the fourth thermometer (8) back and forth in the radial direction of the electromagnetic coil. Both ends of the third thermometer (7) and the fourth thermometer (8) are provided with vertically extending shielding boxes (10). Corresponding to the gap position between adjacent electromagnetic coils, the end face of the shielding box (10) facing the gap is set in a V-shape, and both sides of the V-shape face the electromagnetic coil. The bottom of the shielding box (10) is fixed with a mounting base (11) between it and the frame (1). A connecting pipe (12) for air extraction is provided inside the shielding box (10). A fan is connected to the top of the connecting pipe (12). Multiple vertically distributed air pipes (13) are provided on both sides of the V-shape. The air pipes (13) are connected to the connecting pipe (12). The central controller is also connected to the fan signal and further performs the following steps: D. Determine the desired temperature of the gap region based on the real-time temperature setpoints and working efficiency of the coils on both sides of the gap. In step D, the desired temperature is determined by: calculating the average value of the real-time temperature setpoints of the coils on both sides as the base value, and then weighting and correcting the base value based on the working efficiency of the coils on both sides. E. Adjust the exhaust fan intensity based on the deviation between the desired temperature and the actual average temperature measured by the temperature sensor, where the actual average temperature... It is based on the readings of N thermocouples inside the shielding box. calculate: ; F. A comprehensive health index is generated based on gap temperature uniformity, workpiece surface temperature uniformity, normalized energy efficiency ratio, and coil current imbalance, which is used for equipment early warning and fault location. Among them, the uniformity of gap temperature The calculation formula is: ; Workpiece surface temperature uniformity It utilizes a temperature measuring instrument mounted on an electric guide rail to scan the workpiece radially. Points are used to obtain the temperature array. The calculation formula is: , The average temperature is the scanned temperature. Normalized energy efficiency ratio The calculation formula is: ,in , For ambient temperature, It is the sum of the active power of two adjacent coil power sources. It is a very small constant. Reference power; Coil current imbalance It calculates the degree of difference in current between two adjacent coils; In step F, the comprehensive health index is generated by normalizing four characteristic parameters: gap temperature uniformity, workpiece surface temperature uniformity, normalized energy efficiency ratio, and current imbalance, and then performing a weighted summation.

2. The multi-speed intelligent temperature control induction heating device according to claim 1, characterized in that, In step B, the work performance evaluation specifically includes: For each electromagnetic coil, the theoretical power requirement for heating the workpiece is estimated by using the preset thermodynamic feedforward coefficient, real-time speed data, and the difference between the previous dynamic temperature setpoint of the coil and the current inlet temperature. The theoretical power requirement is then compared with the actual electrical power input fed back in real time by the heating power supply corresponding to the coil to obtain the efficiency factor characterizing the current energy conversion efficiency of the coil.

3. The multi-speed intelligent temperature control induction heating device according to claim 1, characterized in that, In step B, the dynamic allocation method of temperature adjustment is as follows: the real-time efficiency factor of each coil is used as part of the weight for proportional allocation, and the coil with higher efficiency factor receives a larger adjustment amount. The final adjustment amount is then determined by combining the preset fixed allocation coefficient.

4. The multi-speed intelligent temperature control induction heating device according to claim 1, characterized in that, In step C, the power command is calculated as follows: the feedforward power term is calculated based on the real-time temperature setpoint, speed, and inlet temperature. The feedback power term is calculated by the feedback controller based on the deviation between the real-time temperature setpoint and the outlet temperature. The compensation power term is calculated based on whether the current of the heating power supply and the temperature of the device exceed the safety threshold. The final power command is obtained by adding the power of feedforward, feedback, and compensation.

5. The multi-speed intelligent temperature control induction heating device according to claim 4, characterized in that, The calculation of the compensation power term includes: When the output current of the heating power supply exceeds the safe current threshold, a negative current compensation value is generated based on the magnitude of the excess. When the temperature of critical components inside the power supply exceeds the safe temperature threshold, a negative temperature compensation value is generated based on the magnitude of the exceedance. The compensation power term is the sum of the current compensation value and the temperature compensation value.

Images