Process parameter optimization method and system applied to wire and cable conductor

Abstract

The invention relates to the technical field of material processing, in particular to a process parameter optimization method applied to a wire and cable conductor. The method comprises the following steps: measuring the surface temperature of a conductor before entering an annealing furnace and the surface temperature of the conductor after exiting from the annealing furnace in real time, and recording the running speed and the diameter of the conductor at the same time; when the conductor passes through the annealing furnace, a temperature detection device is used for contacting the surface of the conductor and measuring the actual temperature to obtain temperature distribution data of the conductor in the annealing furnace; calculating the heat capacity characteristic value of the conductor according to the running speed and the diameter of the conductor, and calculating the temperature change rate between the adjacent temperature detection devices in combination with the temperature distribution data; and according to the deviation between the surface temperature after exiting the annealing furnace and the preset target temperature, the heating power of each temperature zone of the annealing furnace is reversely adjusted. According to the invention, optimization of the wire and cable conductor process parameters is realized, and the product quality problem caused by unstable process parameters can be effectively avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of material processing, and in particular to a method and system for optimizing process parameters of a wire and cable conductor. BACKGROUND

[0002] In the production workshop of ultra-fine enameled wire, the process stability of the conductor annealing process directly determines the matching degree of the product conductivity and mechanical properties. The current mainstream process adopts a segmented annealing furnace to realize the control of the copper wire crystallization process through multi-temperature zone combination. The operator usually sets the reference value of each temperature zone according to experience, and then adjusts it according to the offline sampling detection results. This control mode can still meet the needs in the production of conventional size wires, but when facing ultra-fine specifications with a wire diameter less than 0.05 mm, the temperature gradient effect of the conductor surface and the core will significantly affect the recrystallization process.

[0003] The prior art relies on fixed thermocouples installed on the wall of the annealing furnace for temperature monitoring. This measurement method has essential limitations. Because the actual temperature of the ultra-fine conductor deviates significantly from the detection value of the furnace wall when it passes through the annealing furnace at high speed (typical wire speed up to 200-300 meters / minute). SUMMARY

[0004] Therefore, it is necessary to provide a method and system for optimizing process parameters of a wire and cable conductor to solve at least one of the above technical problems.

[0005] To achieve the above-mentioned purpose, a method for optimizing process parameters of a wire and cable conductor comprises the following steps: Step S1: Real-time measurement of the surface temperature before the conductor enters the annealing furnace and the surface temperature after the conductor exits the annealing furnace, recording the running speed of the conductor and the diameter of the conductor; Step S2: Contacting the conductor surface with a temperature detection device and measuring the actual temperature when the conductor passes through the annealing furnace to obtain the temperature distribution data of the conductor in the annealing furnace; Step S3: Calculating the heat capacity characteristic value of the conductor according to its running speed and diameter, and calculating the temperature change rate between adjacent temperature detection devices in combination with the temperature distribution data; Step S4: Reverse adjustment of the heating power of each temperature zone of the annealing furnace according to the deviation of the surface temperature after exiting the annealing furnace from the preset target temperature; Step S5: Adjustment of the contact pressure of the adjustable thermocouple according to the product of the temperature change rate and the heat capacity characteristic value; Step S6: Repeating steps S1 to S5 until the surface temperature after exiting the annealing furnace falls within the target temperature range and the fluctuation amplitude of the temperature change rate is less than the allowable error in three consecutive measurements, and finally determining the optimal heating power parameters of each temperature zone.

[0006] Preferably, the application also provides an application for wire and cable conductor process parameter optimization system for executing the application for wire and cable conductor process parameter optimization method as described above, the application for wire and cable conductor process parameter optimization system comprises: a temperature measurement module for measuring the surface temperature before the conductor enters the annealing furnace and the surface temperature after the conductor exits the annealing furnace in real time, and recording the running speed of the conductor and the diameter of the conductor; a temperature detection module for contacting the surface of the conductor with the temperature detection device and measuring the actual temperature when the conductor passes through the annealing furnace, and obtaining the temperature distribution data of the conductor in the annealing furnace; a heat capacity calculation module for calculating the heat capacity characteristic value of the conductor according to the running speed of the conductor and the diameter of the conductor, and combining the temperature distribution data to calculate the temperature change rate between adjacent temperature detection devices; a power adjustment module for reversely adjusting the heating power of each temperature zone of the annealing furnace according to the deviation of the surface temperature after the conductor exits the annealing furnace from the preset target temperature; a pressure adjustment module for adjusting the contact pressure of the adjustable thermocouple according to the product of the temperature change rate and the heat capacity characteristic value; an optimization cycle module for repeating steps S1 to S5 until the surface temperature after the conductor exits the annealing furnace in the continuous three measurements falls within the target temperature range and the fluctuation amplitude of the temperature change rate is less than the allowable error, and finally determining the optimal heating power parameters of each temperature zone.

[0007] The application has the following beneficial effects: On the one hand, the actual temperature of the conductor can be more accurately obtained by contacting the surface of the conductor with the temperature detection device compared with the measurement method of the fixed thermocouple installed on the wall of the annealing furnace in the prior art, effectively solving the problem of significant deviation between the actual temperature of the ultra-fine conductor and the detection value of the furnace wall when the conductor passes through the annealing furnace at high speed, and providing a more reliable data basis for the subsequent optimization of process parameters.

[0008] On the other hand, the heating power of each temperature zone of the annealing furnace is reversely adjusted according to the deviation of the surface temperature after the conductor exits the annealing furnace from the preset target temperature, and the contact pressure of the adjustable thermocouple is adjusted according to the product of the temperature change rate and the heat capacity characteristic value, so that the adjustment of the heating power is more accurate and can better adapt to conductors of different diameters and running speeds, effectively improving the stability and controllability of the annealing process.

[0009] On the other hand, by repeating the measurement and adjustment until the surface temperature after the conductor exits the annealing furnace in the continuous three measurements falls within the target temperature range and the fluctuation amplitude of the temperature change rate is less than the allowable error, the optimal heating power parameters of each temperature zone are finally determined, the optimization of the process parameters of the wire and cable conductor is realized, the product quality problems caused by unstable process parameters can be effectively avoided, and the quality and consistency of the products are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Other features, objects and advantages of the present invention will become more apparent from reading the detailed description made with reference to the following drawings: Fig. 1 A schematic flow chart of the steps of a method for optimizing process parameters of wire and cable conductors according to one embodiment is shown.

[0011] Fig. 2 A schematic flow chart showing detailed steps of a method for calculating a heat capacity characteristic value according to an embodiment is shown.

[0012] Fig. 3 A schematic structural diagram of a temperature detection device contact control system according to an embodiment is shown.

[0013] Fig. 4 A physical schematic diagram of a wire and cable conductor according to an embodiment is shown. DETAILED DESCRIPTION

[0014] The following is a clear and complete description of the technical method of the present invention in conjunction with the accompanying drawings. It is obvious that the embodiments described are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts are within the scope of protection of the present invention.

[0015] In addition, the accompanying drawings are merely schematic illustrations of the present invention and are not necessarily drawn to scale. Identical reference numerals in the figures denote identical or similar parts, and thus repetitive descriptions thereof will be omitted. Some of the block diagrams shown in the accompanying drawings are functional entities that do not necessarily correspond to physically or logically separate entities. These functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor and / or microcontroller approaches.

[0016] It should be understood that although the terms "first," "second," and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used solely to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element, without departing from the scope of the exemplary embodiments. The term "and / or" as used herein includes any and all combinations of one or more of the listed associated items.

[0017] To achieve this, please refer to Figs. 1 to 4 The present invention provides a method for optimizing process parameters of wire and cable conductors, comprising the following steps: Step S1: Real-time measure the surface temperature before the conductor enters the annealing furnace and after the conductor exits the annealing furnace, record the running speed of the conductor and the diameter of the conductor at the same time; Step S2: Contact the surface of the conductor with the temperature detection device when the conductor passes through the annealing furnace and measure the actual temperature to obtain the temperature distribution data of the conductor in the annealing furnace; Step S3: Calculate the heat capacity characteristic value of the conductor according to the running speed of the conductor and the diameter of the conductor, and calculate the temperature change rate between adjacent temperature detection devices in combination with the temperature distribution data; Step S4: According to the deviation of the surface temperature after the conductor exits the annealing furnace from the preset target temperature, adjust the heating power of each temperature zone of the annealing furnace in reverse; Step S5: Adjust the contact pressure of the adjustable thermocouple according to the product of the temperature change rate and the heat capacity characteristic value; Step S6: Repeat steps S1 to S5 until the surface temperature after the conductor exits the annealing furnace in the last three consecutive measurements falls within the target temperature range and the fluctuation amplitude of the temperature change rate is less than the allowable error, and finally determine the optimal heating power parameters of each temperature zone.

[0018] Preferably, the locking condition of the optimal process parameters further includes: After the surface temperature after the conductor exits the annealing furnace and the temperature change rate in the last three consecutive detections meet the preset standard, a conductor sample is cut from the current running section of the production line, and the conductor sample is immediately placed in a constant temperature and humidity environment to cool to 25±1℃; In one implementation manner of the embodiment of the present application, it is assumed that in a certain one of the last three consecutive detections, the surface temperature after the conductor exits the annealing furnace is 200℃, 201℃ and 200.5℃ respectively, and the temperature change rate is 0.05℃ / s, 0.06℃ / s and 0.05℃ / s respectively, all of which meet the preset standard (the preset surface temperature range is 195℃-205℃, and the allowable error of the temperature change rate is ±0.07℃ / s). At this time, a conductor sample with a length of 1 meter is cut from the current running section of the production line, and is placed in a constant temperature and humidity box, the target temperature is set to 25℃, the humidity is set to 50%RH, and the cooling program is started. After 10 minutes of cooling, the temperature of the conductor sample stabilizes at 25℃.

[0019] The conductor sample is subjected to a tensile test, and the maximum tensile strength value before breaking is recorded, and the conductivity of the sample is measured at the same time; The measured tensile strength value is compared with the preset standard strength value, and the relative deviation percentage of the tensile strength value is calculated; The measured conductivity value is compared with the preset standard conductivity value, and the relative deviation percentage of the conductivity value is calculated; In the embodiment of the present application, the conductor sample is subjected to a tensile test, and the maximum tensile strength value before fracture is recorded, and the conductivity of the sample is measured. Specifically, the tensile test is performed on a standard material testing machine, and a gradually increasing tensile force is applied to the conductor sample according to the test method specified in the international standard (such as ISO 6892-1), until the sample is broken, and the maximum tensile strength value before fracture is recorded. The measurement of the conductivity is carried out in a constant temperature and humidity environment, and the conductivity tester is used to measure the conductor sample.

[0020] In one implementation of the embodiment of the present application, the maximum tensile strength value before fracture of the conductor sample is measured to be 220 MPa, and the conductivity is measured to be 58 MS / m. Assuming that the preset standard strength value is 210 MPa and the preset standard conductivity is 60 MS / m, the relative deviation percentage of the tensile strength value is , and the relative deviation percentage of the conductivity value is Since the relative deviation percentage of the tensile strength value is not more than 5%, and the relative deviation percentage of the conductivity value is not more than 3%, the preset standard is met.

[0021] If the relative deviation percentage of the tensile strength value is not more than 5% and the relative deviation percentage of the conductivity value is not more than 3%, a process parameter locking instruction is generated, and the power parameters of the current temperature zones, the thermocouple contact pressures, and the detection period parameters are written into the non-volatile memory. If either of the relative deviation percentage of the tensile strength value and the relative deviation percentage of the conductivity value exceeds the tolerance range, the last three detection data are cleared, the annealing furnace power is reset to the initial default value, and the optimization process is restarted from step S1.

[0022] In one implementation of the embodiment of the present application, according to the tensile test and conductivity measurement results described above, since the relative deviation percentage of the tensile strength value is 4.76% and the relative deviation percentage of the conductivity value is 3.33%, both of which do not exceed the tolerance range, a process parameter locking instruction is generated, and the power parameters of the current temperature zones, the thermocouple contact pressures, and the detection period parameters are written into the non-volatile memory. Assuming that the power parameters of the current temperature zones are 150 kW, 120 kW, and 100 kW respectively, the thermocouple contact pressures are 0.5 N, 0.6 N, and 0.7 N respectively, and the detection period is 10 seconds, these parameters are successfully written into the non-volatile memory, and the locking of the optimal process parameters is completed.

[0023] In another implementation of the embodiment of the application, it is assumed that in a certain detection, the relative deviation percentage of the measured tensile strength value is 6%, and the relative deviation percentage of the conductivity value is 4%, which exceeds the preset standard. At this time, the last three detection data are cleared, the annealing furnace power is reset to the initial default value (assuming 100 kW, 80 kW and 60 kW), and the optimization process is restarted from step S1.

[0024] Preferably, the temperature detection device in step S2 comprises adjustable thermocouples symmetrically distributed on both sides of the furnace wall, and the contact control of the adjustable thermocouples comprises: The contact pressure of each adjustable thermocouple is set to an initial pressure value, and the conductor diameter is calibrated by a laser diameter gauge before the conductor enters the annealing furnace to generate a calibrated conductor diameter. In one implementation of the embodiment of the application, it is assumed that the initial pressure value is set to 0.3 N. Before the conductor enters the annealing furnace, the laser diameter gauge measures the conductor diameter to be 0.045 mm, and the calibrated conductor diameter is generated to be 0.045 mm. The control system sets the contact pressure of each adjustable thermocouple to 0.3 N according to the preset initial pressure value.

[0025] When the conductor passes through, if the calibrated conductor diameter is less than a preset first threshold value, the contact pressure of the adjustable thermocouple is maintained at the initial pressure value, and if the calibrated conductor diameter is within a range from the preset first threshold value to a preset second threshold value, the contact pressure is increased by 0.1 N for each increase of 0.01 mm in diameter, and the maximum is not more than a preset maximum pressure value. If the calibrated conductor diameter exceeds the preset second threshold value, the contact pressure of the adjustable thermocouple is fixed to the preset maximum pressure value.

[0026] In one implementation of the embodiment of the application, it is assumed that the preset first threshold value is 0.05 mm, the preset second threshold value is 0.07 mm, and the preset maximum pressure value is 0.8 N. When the conductor passes through the annealing furnace, the laser diameter gauge measures the conductor diameter in real time to be 0.06 mm. According to the preset rule, the contact pressure is increased by 0.1 N for each increase of 0.01 mm in diameter. Therefore, the contact pressure is increased from the initial 0.3 N to 0.5 N (0.3 N + 0.2 N = 0.5 N). If the conductor diameter is 0.08 mm, which exceeds the preset second threshold value, the contact pressure will be fixed to 0.8 N.

[0027] Especially important is that after adjusting the contact pressure of the adjustable thermocouple, it further comprises: The response time of the adjustable thermocouple is recorded synchronously, and if the response time exceeds 50 ms, the current detection is stopped, the adjustable thermocouple is retracted to the initial position, the compressed air injection device is started to clean the contact end of the adjustable thermocouple for 1 second, and after the cleaning is completed, the adjustable thermocouple is re-extended and the contact pressure is reset to the initial pressure value. In one implementation of the embodiment of the application, assume that in a certain detection, the adjusted contact pressure is 0.5 N, and the response time of the thermocouple is 60 ms, which exceeds the preset 50 ms. The control system stops the current detection, controls the retractable thermocouple to retract to the initial position, and starts the compressed air jet device to clean the contact end of the thermocouple for 1 second. After cleaning, the retractable thermocouple is extended again, and the contact pressure is reset to the initial pressure value of 0.3 N.

[0028] If the response time still exceeds the limit after three consecutive self-cleaning, the retractable thermocouple is marked as a fault state and a backup detection unit is enabled.

[0029] In one implementation of the embodiment of the application, assume that after three consecutive cleanings, the response times of the thermocouple are 65 ms, 62 ms, and 68 ms, respectively, all of which exceed the preset 50 ms. The control system marks the retractable thermocouple as a fault state and enables a backup detection unit to continue temperature detection.

[0030] Preferably, the trigger condition of contact pressure adjustment in step S5 includes: When the product of the temperature change rate and the heat capacity characteristic value exceeds a preset first product threshold, the current contact pressure value of the retractable thermocouple is increased by a preset proportion, and the adjusted contact pressure value is recorded; at the same time, real-time monitoring of the contact pressure is started, and if the adjusted contact pressure value exceeds a preset upper limit, a pressure over-limit alarm is triggered and the process parameter optimization process is suspended. In one implementation of the embodiment of the application, assume that in a certain detection, the temperature change rate is 0.08℃ / s, and the heat capacity characteristic value is 15 J / (kg·℃), so the product is 1.2. The preset first product threshold is 1.2, the preset proportion is 10%, and the preset upper limit is 1.0 N. The current contact pressure value is 0.8 N. According to the trigger condition, the contact pressure value is increased by 10%, i.e. 0.08 N, and the adjusted contact pressure value is 0.88 N. The control system records the adjusted contact pressure value and starts real-time monitoring of the contact pressure. If the adjusted contact pressure value exceeds 1.0 N, a pressure over-limit alarm is triggered and the process parameter optimization process is suspended.

[0031] When the product of the temperature change rate and the heat capacity characteristic value is lower than a preset second product threshold, the current contact pressure value of the retractable thermocouple is decreased by a preset proportion, and the adjusted contact pressure value is recorded; if the adjusted contact pressure value is lower than a preset lower limit, a pressure deficiency alarm is triggered and the contact pressure is automatically reset to the initial pressure value.

[0032] In an embodiment of the present invention, when the product of the temperature change rate and the heat capacity characteristic value is lower than a preset second product threshold, the current contact pressure value of the adjustable thermocouple is reduced by a preset ratio, and the adjusted contact pressure value is recorded; if the adjusted contact pressure value is lower than the preset lower limit, an insufficient pressure alarm is triggered and the contact pressure is automatically reset to the initial pressure value. It is particularly important that after each contact pressure adjustment, it also includes checking whether the adjusted contact pressure value is within the valid range of 0.2 N to 1.0 N; if it exceeds the valid range, the current process parameters are locked and an abnormality log is generated; if it is within the valid range, the process parameter optimization process of step S6 is continued. Specifically, the preset second product threshold is 0.8, the preset ratio is 10%, and the preset lower limit is 0.2 N. The control system calculates the product of the temperature change rate and the heat capacity characteristic value in real time, and adjusts the contact pressure of the thermocouple according to the product value.

[0033] In one implementation of an embodiment of the present invention, assuming that in a certain detection, the temperature change rate is 0.04°C / s, and the heat capacity characteristic value is 10J / (kg·°C), the product is 0.4. The preset second product threshold is 0.8, the preset ratio is 10%, and the preset lower limit is 0.2 Newtons. The current contact pressure value is 0.6 Newtons. According to the trigger condition, the contact pressure value is reduced by 10%, that is, reduced by 0.06 Newtons, and the adjusted contact pressure value is 0.54 Newtons. The control system records the adjusted contact pressure value. If the adjusted contact pressure value is lower than 0.2 Newtons, the insufficient pressure alarm is triggered and the contact pressure is automatically reset to the initial pressure value of 0.3 Newtons. After adjustment, the control system verifies whether the contact pressure value is within the valid range of 0.2 Newtons to 1.0 Newtons. If it exceeds the valid range, the current process parameters are locked and an abnormality log is generated; if it is within the valid range, the process parameter optimization process of step S6 is continued.

[0034] It is especially important that after each contact pressure adjustment, also include: Verify whether the adjusted contact pressure value is within the valid range of 0.2 N to 1.0 N; if it is outside the valid range, lock the current process parameters and generate an abnormality log; if it is within the valid range, continue to execute the process parameter optimization process of step S6.

[0035] Preferably, the method for calculating the heat capacity characteristic value in step S3 includes: The pre-stored heat capacity coefficient comparison table is queried based on the conductor diameter and operating speed. The heat capacity coefficient comparison table is generated by calibrating the steady-state thermal balance data of conductors of different diameters at typical operating speeds in the laboratory. The closest diameter and speed gear are matched to obtain the benchmark heat capacity value. In one implementation of the embodiment of the present application, it is assumed that the current conductor diameter is 0.06 mm and the running speed is 250 m / min. The thermal capacity coefficient table records the reference thermal capacity values at different diameters (0.05 mm, 0.06 mm, 0.07 mm, etc.) and different speeds (200 m / min, 250 m / min, 300 m / min, etc.). The system matches the reference thermal capacity value of 0.08 J / (kg·℃) at the diameter of 0.06 mm and the running speed of 250 m / min.

[0036] extracting a maximum temperature difference between adjacent detection devices in the temperature distribution data, and when the maximum temperature difference exceeds a preset threshold temperature difference; If the maximum temperature difference is located in the high-temperature section of the annealing furnace, the quotient of the maximum temperature difference divided by the reference temperature difference value of the high-temperature section is taken as the first correction value. If the maximum temperature difference is located in the low-temperature section of the annealing furnace, the quotient of the maximum temperature difference divided by the reference temperature difference value of the low-temperature section is taken as the second correction value. In the embodiment of the present application, the preset threshold temperature difference is 5℃. If the maximum temperature difference is located in the high-temperature section of the annealing furnace, the quotient of the maximum temperature difference divided by the reference temperature difference value of the high-temperature section is taken as the first correction value. If the maximum temperature difference is located in the low-temperature section of the annealing furnace, the quotient of the maximum temperature difference divided by the reference temperature difference value of the low-temperature section is taken as the second correction value. The reference temperature difference value of the high-temperature section is 10℃, and the reference temperature difference value of the low-temperature section is 8℃.

[0037] In one implementation of the embodiment of the present application, it is assumed that the temperature distribution data shows that the maximum temperature difference between adjacent detection devices is 6℃, and the maximum temperature difference is located in the high-temperature section of the annealing furnace. The reference temperature difference value of the high-temperature section is 10℃, so the first correction value is If the maximum temperature difference is 7℃ and located in the low-temperature section, the reference temperature difference value of the low-temperature section is 8℃, so the second correction value is .

[0038] The reference thermal capacity value is multiplied by the first correction value or the second correction value to obtain a final thermal capacity characteristic value. The reference temperature difference value of the high-temperature section is the maximum allowable temperature difference of the high-temperature section of the annealing furnace under standard working conditions, and the reference temperature difference value of the low-temperature section is the maximum allowable temperature difference of the low-temperature section of the annealing furnace under standard working conditions.

[0039] In the embodiment of the present application, the reference thermal capacity value is multiplied by the first correction value or the second correction value to obtain a final thermal capacity characteristic value. Specifically, the corresponding correction value is selected according to the section where the maximum temperature difference is located, and multiplied by the reference thermal capacity value to obtain the final thermal capacity characteristic value.

[0040] In one implementation of the embodiment of the application, it is assumed that the reference heat capacity value is 0.08 J / (kg·℃), and the first correction value is 0.6 (the maximum temperature difference is located in the high-temperature section). The final heat capacity characteristic value is 0.08*0.6=0.048 J / (kg·℃). If the maximum temperature difference is located in the low-temperature section, the second correction value is 0.875, and the final heat capacity characteristic value is 0.08*0.875=0.07 J / (kg·℃).

[0041] Preferably, the specific rule of reverse adjustment of the heating power in step S4 comprises: If the surface temperature deviation after the conductor exits the annealing furnace is a positive value and the temperature change rate exceeds the preset first change rate, the power of the high-temperature section of the annealing furnace is reduced by a preset first proportion, and the power of the low-temperature section is increased by a preset second proportion, wherein the surface temperature deviation is the difference between the actual surface temperature of the conductor after it exits the annealing furnace and the middle value of the preset target temperature interval. In one implementation of the embodiment of the application, it is assumed that the middle value of the preset target temperature interval is 200℃, and the actual surface temperature of the conductor after it exits the annealing furnace is 205℃, and the surface temperature deviation is +5℃. At the same time, the temperature change rate is 0.12℃ / s, which exceeds the preset first change rate of 0.1℃ / s. According to the rule, the power of the high-temperature section of the annealing furnace is reduced by 10%, and the power of the low-temperature section is increased by 5%. Assuming that the initial power of the high-temperature section is 150kW and the initial power of the low-temperature section is 100kW, the adjusted powers are 135kW and 105kW, respectively.

[0042] If the surface temperature deviation after the conductor exits the annealing furnace is a negative value and the temperature change rate is lower than the preset second change rate, the power of the high-temperature section of the annealing furnace is increased by a preset third proportion, and the power of the low-temperature section is reduced by a preset fourth proportion. The preset first change rate is greater than the preset second change rate, and at least 30 seconds of stable operation time is required after each adjustment, during which all detection and adjustment operations are suspended. In the embodiment of the application, if the surface temperature deviation after the conductor exits the annealing furnace is a negative value and the temperature change rate is lower than the preset second change rate, the power of the high-temperature section of the annealing furnace is increased by a preset third proportion, and the power of the low-temperature section is reduced by a preset fourth proportion. Specifically, the preset second change rate is 0.05℃ / s, the preset third proportion is 15%, and the preset fourth proportion is 10%. The control system automatically adjusts the heating power of each temperature section according to the real-time data of the surface temperature deviation and the temperature change rate.

[0043] In one implementation of the embodiment of the application, it is assumed that the preset target temperature interval is 200℃, the actual surface temperature of the conductor after exiting the annealing furnace is 195℃, and the surface temperature deviation is -5℃. At the same time, the temperature change rate is 0.04℃ / s, which is lower than the preset second change rate 0.05℃ / s. According to the rule, the power of the high-temperature zone of the annealing furnace is increased by 15%, and the power of the low-temperature zone is decreased by 10%. Assuming that the initial power of the high-temperature zone is 150kW and the initial power of the low-temperature zone is 100kW, the adjusted powers are 172.5kW and 90kW, respectively.

[0044] When the temperature change rate is between the preset second change rate and the preset first change rate, the current power of each temperature zone is maintained unchanged.

[0045] In one implementation of the embodiment of the application, it is assumed that in a certain detection, the temperature change rate is 0.08℃ / s, which is between the preset second change rate 0.05℃ / s and the preset first change rate 0.1℃ / s. At this time, the control system maintains the current power of each temperature zone unchanged. Assuming that the current power of the high-temperature zone is 150kW and the power of the low-temperature zone is 100kW, these powers remain unchanged in the next 30 seconds, and the control system suspends all detection and adjustment operations during this period to ensure stable operation of the heating power after adjustment.

[0046] Preferably, the method for setting the allowable error in step S6 comprises: determining a basic error threshold according to the diameter of the conductor; In the embodiment of the application, the method for setting the allowable error in step S6 comprises determining a basic error threshold according to the diameter of the conductor. Specifically, the basic error threshold is preset according to the diameter of the conductor, and different diameters of the conductor correspond to different basic error thresholds. These values are stored in the database of the system, and by inputting the diameter of the current conductor, the system automatically matches the corresponding basic error threshold.

[0047] In one implementation of the embodiment of the application, it is assumed that the current diameter of the conductor is 0.06mm. The preset basic error threshold in the system database is: the diameter of 0.05mm corresponds to the basic error threshold ±1.0℃, the diameter of 0.06mm corresponds to the basic error threshold ±1.2℃, and the diameter of 0.07mm corresponds to the basic error threshold ±1.4℃. Therefore, the system matches the basic error threshold of the diameter of 0.06mm to ±1.2℃.

[0048] If the running speed increases by a preset speed increment threshold, the basic error threshold is tightened by 0.1℃ to generate a corrected error threshold; If the running speed is reduced by a preset speed decrement threshold, the base error threshold is relaxed by 0.1 degrees Celsius to generate a modified error threshold; wherein the modified error threshold needs to meet a minimum allowable error of ±0.5 degrees Celsius and a maximum allowable error of ±3 degrees Celsius; In an implementation manner of the embodiment of the present application, it is assumed that the current running speed is 250 m / min, the preset speed increment threshold is 50 m / min, and the preset speed decrement threshold is 50 m / min. The base error threshold is ±1.2 degrees Celsius. If the running speed is increased to 300 m / min, which is increased by 50 m / min, the base error threshold is tightened by 0.1 degrees Celsius, and the modified error threshold is ±1.1 degrees Celsius. If the running speed is reduced to 200 m / min, which is reduced by 50 m / min, the base error threshold is relaxed by 0.1 degrees Celsius, and the modified error threshold is ±1.3 degrees Celsius.

[0049] In the continuous three detections, if the surface temperatures after exiting the annealing furnace all fall within the range of the modified error threshold, it is determined that the process parameter optimization is completed.

[0050] In the embodiment of the present application, the modified error threshold needs to meet a minimum allowable error of ±0.5 degrees Celsius and a maximum allowable error of ±3 degrees Celsius. In the continuous three detections, if the surface temperatures after exiting the annealing furnace all fall within the range of the modified error threshold, it is determined that the process parameter optimization is completed. Specifically, the control system checks whether the minimum and maximum allowable error ranges are met after adjusting the error threshold each time, and records whether the surface temperatures are within the range of the modified error threshold in the continuous three detections.

[0051] In an implementation manner of the embodiment of the present application, it is assumed that the adjusted modified error threshold is ±1.1 degrees Celsius, which meets the requirements of the minimum allowable error of ±0.5 degrees Celsius and the maximum allowable error of ±3 degrees Celsius. In the continuous three detections, the surface temperatures after exiting the annealing furnace are 200.3℃, 200.4℃ and 199.8℃ respectively, and the preset target temperature is 200℃, so the surface temperatures of the three detections are all within the range of the modified error threshold of ±1.1 degrees Celsius. Therefore, the control system determines that the process parameter optimization is completed.

[0052] Preferably, step S1 comprises: A first infrared temperature measuring instrument is installed at the entrance of the annealing furnace, and the optical axis thereof forms a first included angle with the running direction of the conductor, so as to measure the surface temperature of the conductor before entering the annealing furnace in real time, wherein the range of the first included angle is 25 degrees to 35 degrees; In an implementation manner of the embodiment of the present application, it is assumed that the first included angle is set to 30 degrees. The first infrared temperature measuring instrument is installed at the entrance of the annealing furnace, and the optical axis thereof forms a 30-degree angle with the running direction of the conductor. When the conductor enters the annealing furnace, the first infrared temperature measuring instrument measures the surface temperature of the conductor in real time, and the measurement result shows that the surface temperature of the conductor is 180℃.

[0053] A second infrared temperature measuring instrument is installed at the outlet of the annealing furnace, and the optical axis of the second infrared temperature measuring instrument forms a second included angle with the running direction of the conductor, and the surface temperature of the conductor after exiting the annealing furnace is measured in real time, wherein the second included angle ranges from 40 degrees to 50 degrees. In an implementation manner of the embodiment of the present application, it is assumed that the second included angle is set to 45 degrees. The second infrared temperature measuring instrument is installed at the outlet of the annealing furnace, and the optical axis of the second infrared temperature measuring instrument forms a 45-degree angle with the running direction of the conductor. When the conductor exits the annealing furnace, the second infrared temperature measuring instrument measures the surface temperature of the conductor in real time, and the measurement result shows that the surface temperature of the conductor is 205 DEG C.

[0054] The running speed of the conductor is collected in real time by the encoder installed at the inlet side of the annealing furnace. In an implementation manner of the embodiment of the present application, it is assumed that the encoder is installed on the conductor transmission device at the inlet side of the annealing furnace. When the conductor enters the annealing furnace, the encoder collects the running speed of the conductor in real time, and the measurement result shows that the running speed of the conductor is 250 meters per minute.

[0055] Before the conductor enters the annealing furnace, the conductor diameter of the conductor is measured by the laser diameter measuring instrument for three times continuously, and the average value of the three measurement results is taken as the conductor diameter of the conductor.

[0056] In an implementation manner of the embodiment of the present application, it is assumed that the laser diameter measuring instrument is installed at the inlet of the annealing furnace. Before the conductor enters the annealing furnace, the laser diameter measuring instrument measures the conductor diameter for three times continuously, and the measurement results are 0.061 millimeters, 0.060 millimeters and 0.062 millimeters respectively. The average value of the three measurement results is taken to calculate the conductor diameter of the conductor as 0.061 millimeters.

[0057] Preferably, the abnormality processing step is further included after the step S6: When the fluctuation amplitude of the temperature change rate is detected to exceed 150% of the allowable error threshold value for two times continuously, the conductor feeding is paused and the power parameters of each temperature zone of the annealing furnace are locked; In the embodiment of the present application, the abnormality processing step is further included after the step S6: when the fluctuation amplitude of the temperature change rate is detected to exceed 150% of the allowable error threshold value for two times continuously, the conductor feeding is paused and the power parameters of each temperature zone of the annealing furnace are locked. Specifically, the control system monitors the fluctuation amplitude of the temperature change rate in real time, and compares the fluctuation amplitude with the allowable error threshold value. Once it is found that the fluctuation amplitude exceeds 150% of the allowable error threshold value for two times continuously, the pause and locking operations are immediately performed.

[0058] In an implementation manner of the embodiment of the present application, it is assumed that the allowable error threshold is ±0.5℃ / s. In two consecutive detections, the fluctuation amplitudes of the temperature change rates are 0.8℃ / s and 0.9℃ / s respectively, both of which exceed 150% of the allowable error threshold (i.e. 0.75℃ / s). At this time, the control system suspends the conductor feeding, and locks the power parameters of the temperature zones of the annealing furnace, to ensure that the system is in a safe state.

[0059] The auxiliary heater is started to preheat the annealing furnace in an empty state, the preheating temperature is the upper limit value of the current conductor target temperature interval plus 50 degrees Celsius, and the preheating duration is 5 minutes. In an implementation manner of the embodiment of the present application, it is assumed that the upper limit value of the current conductor target temperature interval is 250℃. The preheating temperature is set to 250℃+50℃=300℃. The auxiliary heater is started to preheat the annealing furnace in an empty state, and the preheating duration is 5 minutes. During the preheating process, the control system monitors the furnace temperature in real time to ensure that the preheating temperature reaches 300℃.

[0060] During the preheating process, the following self-checking steps are performed on each temperature detection device in turn: The non-contact infrared thermometer is calibrated by a black body, and the calibration temperature is the preheating temperature; In an implementation manner of the embodiment of the present application, it is assumed that the preheating temperature is 300℃. During the preheating process, the non-contact infrared thermometer is calibrated by a black body, and the calibration temperature is 300℃. The adjustable thermocouple is subjected to a contact pressure cyclic test, and the test range is 0.2N to 1.0N with a test interval of 0.1N. The test results show that the contact pressures of all adjustable thermocouples are within the effective range, and the self-checking steps are completed.

[0061] The adjustable thermocouple is subjected to a contact pressure cyclic test, and the test range is 0.2N to 1.0N with a test interval of 0.1N; After the preheating is completed, all detection devices are reinitialized, and the conductor feeding is resumed to start the process parameter optimization process again with the initial contact pressure value.

[0062] In the embodiment of the present application, after the preheating is completed, the control system automatically reinitializes all detection devices, including the infrared thermometer and the adjustable thermocouple, to ensure that all devices are in a normal working state. The conductor feeding is resumed, and the process parameter optimization process is started again with the initial contact pressure value.

[0063] In an implementation manner of the embodiment of the present application, it is assumed that the initial contact pressure value is 0.3N. After the preheating is completed, the control system reinitializes all detection devices, including the infrared thermometer and the adjustable thermocouple. After confirming that all devices are normal, the conductor feeding is resumed, and the contact pressure of the adjustable thermocouple is set to 0.3N to start the process parameter optimization process again.

[0064] Preferably, the present application also provides an electric wire and cable conductor process parameter optimization system for performing the electric wire and cable conductor process parameter optimization method as described above, the electric wire and cable conductor process parameter optimization system comprising: a temperature measurement module for measuring the surface temperature before the conductor enters the annealing furnace and the surface temperature after the conductor exits the annealing furnace in real time, and recording the running speed of the conductor and the diameter of the conductor; a temperature detection module for contacting the surface of the conductor with a temperature detection device and measuring the actual temperature when the conductor passes through the annealing furnace, to obtain the temperature distribution data of the conductor in the annealing furnace; a heat capacity calculation module for calculating the heat capacity characteristic value of the conductor according to the running speed of the conductor and the diameter of the conductor, and combining the temperature distribution data to calculate the temperature change rate between adjacent temperature detection devices; a power adjustment module for reversely adjusting the heating power of each temperature zone of the annealing furnace according to the deviation of the surface temperature after the conductor exits the annealing furnace from the preset target temperature; a pressure adjustment module for adjusting the contact pressure of the adjustable thermocouple according to the product of the temperature change rate and the heat capacity characteristic value; an optimization cycle module for repeating steps S1 to S5 until the surface temperature after the conductor exits the annealing furnace falls within the target temperature range and the fluctuation amplitude of the temperature change rate is less than the allowable error in three consecutive measurements, and finally determining the optimal heating power parameters of each temperature zone.

[0065] Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, the scope of the present application being defined by the appended claims rather than the above description, and it is intended to encompass all variations falling within the meaning and scope of the equivalent elements of the application file.

[0066] The above description is merely one specific implementation of the application, which enables those skilled in the art to understand or implement the application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for optimizing process parameters of wire and cable conductors, characterized in that: The following steps are involved: Step S1: measuring the surface temperature of the conductor before entering the annealing furnace and after exiting the annealing furnace in real time, and recording the running speed and diameter of the conductor at the same time; Step S2: When the conductor passes through the annealing furnace, a temperature detection device is used to contact the surface of the conductor and measure the actual temperature to obtain temperature distribution data of the conductor in the annealing furnace; Step S3: Calculating the heat capacity characteristic value of the conductor according to the running speed and diameter of the conductor, and calculating the temperature change rate between adjacent temperature detection devices in combination with the temperature distribution data; Step S4: According to the deviation between the surface temperature after exiting the annealing furnace and the preset target temperature, reversely adjust the heating power of each temperature zone of the annealing furnace; Step S5: adjusting the contact pressure of the adjustable thermocouple according to the product of the temperature change rate and the heat capacity characteristic value; Step S6: Repeat steps S1 to S5 until the surface temperature after exiting the annealing furnace falls within the target temperature range in three consecutive measurements and the fluctuation amplitude of the temperature change rate is less than the allowable error, and finally determine the optimal heating power parameters for each temperature zone.

2. The method for optimizing process parameters of wire and cable conductors according to claim 1, characterized in that: The locking conditions for the optimal process parameters also include: When the surface temperature and temperature change rate after exiting the annealing furnace meet the preset standards in three consecutive tests, a conductor sample is cut from the current running section of the production line and immediately placed in a constant temperature and humidity environment to cool to 25±1°C; Conduct a tensile test on the conductor sample, record the maximum tensile strength value before fracture, and simultaneously measure the conductivity of the sample; Compare the measured tensile strength value with the preset standard strength value and calculate the relative deviation percentage of the tensile strength value; Compare the measured conductivity value with the preset standard conductivity value and calculate the relative deviation percentage of the conductivity value; If the relative deviation percentage of the tensile strength value does not exceed 5% and the relative deviation percentage of the conductivity value does not exceed 3%, a process parameter lock instruction is generated to write the current power parameters, thermocouple contact pressure and detection cycle parameters of each temperature zone into the non-volatile memory; If either the relative deviation percentage of the tensile strength value or the relative deviation percentage of the conductivity value exceeds the tolerance range, the latest three test data are cleared, the annealing furnace power is reset to the initial default value, and the process returns to step S1 to restart the optimization process.

3. The method for optimizing process parameters of wire and cable conductors according to claim 1, characterized in that: The temperature detection device in step S2 includes adjustable thermocouples symmetrically distributed on both sides of the furnace wall. The contact control of the adjustable thermocouples includes: The contact pressure of each adjustable thermocouple is set to an initial pressure value, and the conductor diameter is calibrated by a laser caliper before the conductor enters the annealing furnace to generate a calibrated conductor diameter; When the conductor passes through, if the diameter of the calibration conductor is less than the preset first threshold, the contact pressure of the adjustable thermocouple is maintained at the initial pressure value. If the diameter of the calibration conductor is within the range from the preset first threshold to the preset second threshold, the contact pressure is increased by 0.1 Newton for every 0.01 mm increase in diameter, up to a maximum pressure value not exceeding the preset maximum pressure value; If the diameter of the calibration conductor exceeds a preset second threshold value, the contact pressure of the adjustable thermocouple is fixed to a preset maximum pressure value.

4. The method for optimizing process parameters of wire and cable conductors according to claim 1, characterized in that: The triggering conditions for contact pressure adjustment in step S5 include: When the product of the temperature change rate and the heat capacity characteristic value exceeds a preset first product threshold, the current contact pressure value of the adjustable thermocouple is increased by a preset ratio, and the adjusted contact pressure value is recorded; at the same time, real-time monitoring of the contact pressure is started. If the adjusted contact pressure value exceeds the preset upper limit, a pressure over-limit alarm is triggered and the process parameter optimization process is suspended; When the product of the temperature change rate and the heat capacity characteristic value is lower than the preset second product threshold, the current contact pressure value of the adjustable thermocouple is reduced by a preset ratio, and the adjusted contact pressure value is recorded; if the adjusted contact pressure value is lower than the preset lower limit, an insufficient pressure alarm is triggered and the contact pressure is automatically reset to the initial pressure value.

5. The method for optimizing process parameters of wire and cable conductors according to claim 1, characterized in that: The calculation method of the heat capacity characteristic value in step S3 includes: The pre-stored heat capacity coefficient comparison table is queried based on the conductor diameter and operating speed. The heat capacity coefficient comparison table is generated by calibrating the steady-state thermal balance data of conductors of different diameters at typical operating speeds in the laboratory. The closest diameter and speed gear are matched to obtain the benchmark heat capacity value. Extracting the maximum temperature difference between adjacent detection devices in the temperature distribution data, when the maximum temperature difference exceeds a preset threshold temperature difference; If the maximum temperature difference is in the high temperature section of the annealing furnace, the quotient of the maximum temperature difference divided by the reference temperature difference value of the high temperature section is used as the first correction value; If the maximum temperature difference is in the low temperature section of the annealing furnace, the quotient of the maximum temperature difference divided by the reference temperature difference value of the low temperature section is used as the second correction value; Multiply the reference heat capacity value by the first correction value or the second correction value to obtain the final heat capacity characteristic value; among which, the high-temperature section reference temperature difference value is the maximum allowable temperature difference of the high-temperature section of the annealing furnace under standard operating conditions, and the low-temperature section reference temperature difference value is the maximum allowable temperature difference of the low-temperature section of the annealing furnace under standard operating conditions.

6. The method for optimizing process parameters of wire and cable conductors according to claim 1, characterized in that: The specific rules for reversely regulating the heating power in step S4 include: If the surface temperature deviation after exiting the annealing furnace is positive and the temperature change rate exceeds a preset first change rate, the power of the high temperature zone of the annealing furnace is reduced by a preset first ratio, while the power of the low temperature zone is increased by a preset second ratio, wherein the surface temperature deviation is the difference between the actual surface temperature of the conductor after exiting the annealing furnace and the median of the preset target temperature range; If the surface temperature deviation after exiting the annealing furnace is negative and the temperature change rate is lower than the preset second change rate, the power of the high temperature zone of the annealing furnace is increased by a preset third ratio, and the power of the low temperature zone is reduced by a preset fourth ratio; The preset first change rate is greater than the preset second change rate, and after each adjustment, a stable operation time of at least 30 seconds must be waited for, during which all detection and adjustment operations are suspended; When the temperature change rate is between the preset second change rate and the preset first change rate, the current power of each temperature zone is maintained unchanged.

7. The method for optimizing process parameters of wire and cable conductors according to claim 1, characterized in that: The method for setting the allowable error in step S6 includes: Determine the basic error threshold based on the conductor diameter; If the running speed increases by the preset speed increment threshold, the basic error threshold is tightened by 0.1 degrees Celsius to generate a corrected error threshold; If the running speed decreases by the preset speed decrement threshold, the basic error threshold is relaxed by 0.1 degrees Celsius to generate a corrected error threshold; wherein, the corrected error threshold must meet the minimum allowable error of ±0.5 degrees Celsius and the maximum allowable error of ±3 degrees Celsius; In three consecutive tests, if the surface temperature after exiting the annealing furnace falls within the correction error threshold range, it is determined that the process parameter optimization is completed.

8. The method for optimizing process parameters of wire and cable conductors according to claim 1, characterized in that: Step S1 includes: A first infrared thermometer is installed at the entrance of the annealing furnace, with its optical axis forming a first angle with the direction of travel of the conductor, to measure the surface temperature of the conductor before entering the annealing furnace in real time, wherein the range of the first angle is 25 degrees to 35 degrees; A second infrared thermometer is installed at the exit of the annealing furnace, with its optical axis forming a second angle with the direction of travel of the conductor, to measure the surface temperature of the conductor after exiting the annealing furnace in real time, wherein the range of the second angle is 40 degrees to 50 degrees; The running speed of the conductor is collected in real time by an encoder installed at the entrance side of the annealing furnace; Before the conductor enters the annealing furnace, the conductor diameter of the conductor is measured three times continuously by a laser diameter gauge, and the average value of the three measurement results is taken as the conductor diameter of the conductor.

9. The method for optimizing process parameters of wire and cable conductors according to claim 1, characterized in that: After step S6, the following exception handling steps are also included: When it is detected that the fluctuation amplitude of the temperature change rate exceeds 150% of the allowable error threshold for two consecutive times, the conductor feeding is suspended and the power parameters of each temperature zone of the annealing furnace are locked; Start the auxiliary heater to preheat the annealing furnace at no load. The preheating temperature is the upper limit of the current conductor target temperature range plus 50 degrees Celsius, and the preheating time is 5 minutes. During the preheating process, the following self-test steps are performed on each temperature detection device in turn: Perform blackbody calibration on the non-contact infrared thermometer, and the calibration temperature is the preheating temperature; Perform contact pressure cycling tests on adjustable thermocouples with a test range of 0.2 N to 1.0 N and a test interval of 0.1 N. After preheating is complete, all detection devices are reinitialized and the conductor feed is resumed, and the process parameter optimization process begins again with the initial contact pressure value.

10. A process parameter optimization system for wire and cable conductors, characterized in that: Used to execute the method for optimizing process parameters of wire and cable conductors according to claim 1, the system for optimizing process parameters of wire and cable conductors comprises: Temperature measurement module, used to measure the surface temperature of the conductor before entering the annealing furnace and after exiting the annealing furnace in real time, and record the running speed and diameter of the conductor at the same time; The temperature detection module is used to contact the surface of the conductor and measure the actual temperature when the conductor passes through the annealing furnace using a temperature detection device to obtain temperature distribution data of the conductor in the annealing furnace; A heat capacity calculation module is used to calculate the heat capacity characteristic value of the conductor based on the running speed and diameter of the conductor, and to calculate the temperature change rate between adjacent temperature detection devices in combination with the temperature distribution data; The power regulation module is used to reversely adjust the heating power of each temperature zone of the annealing furnace according to the deviation between the surface temperature after exiting the annealing furnace and the preset target temperature; A pressure adjustment module, used for adjusting the contact pressure of the adjustable thermocouple according to the product of the temperature change rate and the heat capacity characteristic value; The optimization cycle module is used to repeat steps S1 to S5 until the surface temperature after exiting the annealing furnace falls within the target temperature range in three consecutive measurements and the fluctuation amplitude of the temperature change rate is less than the allowable error, and finally determine the optimal heating power parameters for each temperature zone.

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