Continuous casting device for processing copper-aluminum composite plate strip

Abstract

The invention relates to the technical field of non-ferrous metal materials, and discloses a continuous casting device for processing a copper-aluminum composite plate strip, which comprises a hot mold, a crystallizer is sleeved outside the other end of the hot mold, a tractor is arranged outside the other end of the hot mold, and a first thermocouple is arranged in the hot mold and near the convergence position of a copper smelting furnace and an aluminum smelting furnace. A third thermocouple and a fourth thermocouple are arranged at the inlet end and the outlet end of the crystallizer respectively, the third thermocouple is used for obtaining temperature parameters of the liquid inlet end of the crystallizer in real time, the fourth thermocouple is used for obtaining temperature parameters of the liquid outlet end of the crystallizer in real time, and the temperature difference obtained by the third thermocouple and the fourth thermocouple feeds back and controls the circulating liquid flow speed of the crystallizer. Thermocouples are respectively arranged at an inlet and an outlet of the crystallizer to detect temperature, temperature parameters of a plate blank at an outlet of the crystallizer are combined and replaced by temperature difference parameters of the inlet and the outlet of cooling liquid, combined control is realized with the temperature of the outlet of the plate blank, and the hysteresis of system control can be reduced by at least more than 1s.

Description

Technical Field

[0001] The invention relates to the technical field of nonferrous metal materials, in particular to a continuous casting device for processing copper-aluminum composite plates and strips. Background Art

[0002] Copper and aluminum are important nonferrous metals. Copper has excellent electrical and thermal conductivity, as well as corrosion resistance, while aluminum has excellent electrical and thermal conductivity. Copper-aluminum composite sheet and strip combines the advantages of copper and aluminum, offering high conductivity, good corrosion resistance, low density, and easy connection. It can replace pure copper sheet and strip in a wide range of applications, including electronics and communications, petrochemicals, transportation, decorative building materials, aerospace, and defense.

[0003] The copper-aluminum composite plate and strip manufactured by bimetallic horizontal continuous casting has the advantages of short process flow, high production efficiency, and metallurgical bonding of the composite interface. The basic principle of the process is: the copper liquid and the aluminum liquid are heated and kept warm respectively. When the temperature reaches the predetermined hot melting temperature, the copper plate is cast by a traction machine. The copper plate and strip are cast first, and then the aluminum liquid is discharged. Under the cooling effect of the crystallizer, the aluminum liquid solidifies on the copper plate. The copper plate and the aluminum liquid are directly compounded in the casting mold, thereby achieving metallurgical bonding.

[0004] When molten aluminum and copper sheets are combined, a bonding interface layer is formed. The thicker this interface layer, the more intermetallic compounds there are, and the lower the bond strength of the composite strip, requiring strict temperature control during the solidification process. Existing processes all rely on installing a temperature measuring device at the exit of the crystallizer to continuously collect real-time temperature data from the continuous-cast copper-aluminum composite slab online. This data is then fed back to the integrated control system, which compares it with the target rated temperature data and formulates a control strategy to adjust the cooling water flow rate of the crystallizer and the continuous casting speed of the traction machine.

[0005] This control strategy uses the real-time temperature of the slab at the crystallizer outlet as a reference for temperature control adjustments. However, since the pulling machine's pulling rate is generally controlled at 800-1500 mm / min, the distance between the solidification point and the outlet causes a constant lag in the outlet temperature feedback. The delayed onset of feedback adjustment prolongs the lag time, causing a lag in interface temperature control. This prevents timely response to abnormal operating conditions in the continuous casting equipment, affecting the quality assurance of the continuously cast products. This application aims to address this lag problem. Summary of the Invention

[0006] In response to the shortcomings of the crystallizer temperature control system of the existing continuous casting equipment raised in the background technology during use, the present invention provides a continuous casting device for processing copper-aluminum composite plates and strips, which has the advantages of improving the timeliness of temperature feedback control and correcting the accumulated temperature difference error, thereby solving the technical problems raised in the background technology.

[0007] The present invention provides the following technical solution: a continuous casting device for processing copper-aluminum composite plates and strips, comprising a hot mold, a copper melting furnace is provided at one end of the hot mold, an aluminum melting furnace is provided at the top of the hot mold, a crystallizer is provided on the outside of the other end of the hot mold, and a traction machine is provided on the outside of the other end of the hot mold, a first thermocouple is provided in the hot mold and near the confluence of the copper melting furnace and the aluminum melting furnace, the first thermocouple is used to obtain the temperature parameters at the point in real time, a second thermocouple is provided near the outlet end of the hot mold, the second thermocouple is used to obtain the real-time temperature parameters of the slab at the outlet of the hot mold, a third thermocouple and a fourth thermocouple are respectively provided at the inlet and outlet ends of the crystallizer, the third thermocouple is used to obtain the temperature parameters of the liquid inlet end of the crystallizer in real time, and the fourth thermocouple is used to obtain the temperature parameters of the liquid outlet end of the crystallizer in real time, the temperature difference obtained by the third thermocouple and the fourth thermocouple is feedback controlled to control the circulating liquid flow rate of the crystallizer, if the temperature difference is larger than the rated value, the circulating flow rate is increased, otherwise the circulating flow rate of the crystallizer is reduced.

[0008] Preferably, when the temperature difference is normal, the real-time temperature parameter obtained by the second thermocouple is compared with the rated value. When normal, the current working state of the equipment is maintained; when abnormal, the traction speed of the traction machine is adjusted.

[0009] Preferably, the circulating liquid flow rate of the crystallizer is regularly corrected, and the correction method is as follows: The first thermocouple, the second thermocouple, the third thermocouple, and the fourth thermocouple are used to obtain the corresponding billet starting section temperature T1, billet outlet section temperature T2, coolant inlet temperature K1, and coolant outlet temperature K2, respectively. The timestamps of T1 and T2 are recorded. The current time t n , obtain T1 through the first thermocouple and the second thermocouple n 、T2 n , retrieve the casting billet t with the timestamp n-1 Time T1 n-1 , calculate the corrected temperature difference ΔTcorrect = T1 n-1 -T2 n , calculate the current temperature difference ΔT = T1 n -T2 n , calculate the correction coefficient η according to the following formula: η=(ΔT 矫 -ΔT 目 ) / ΔT 目 ; Adjust the coolant flow rate according to the correction factor.

[0010] Preferably, when η is a positive value, the cycle cooling rate should be reduced according to the correction coefficient, and vice versa.

[0011] Preferably, the T1 n-1 The value of t is taken as the reference of the current traction speed of the traction machine.n Time and t n-1 The time difference is set as the time taken for the billet to move at the current traction speed of the traction machine.

[0012] Preferably, the positive and negative values ​​of η are in a critical range with a range value near 0, a positive value exceeding the range, and a negative value below the range.

[0013] Preferably, a fifth thermocouple is provided at the outlet end of the crystallizer and located near the top of the aluminum material. The second thermocouple and the fifth thermocouple respectively obtain the outlet section temperature parameters near copper and aluminum, and the average value of the two temperature parameters is taken to replace the original billet outlet section temperature T2 parameter value.

[0014] The present invention has the following beneficial effects: 1. The present invention sets thermocouples to detect the temperature at the inlet and outlet of the crystallizer respectively, and combines the temperature parameters of the slab at the outlet of the crystallizer with the temperature difference parameter of the coolant inlet and outlet as a substitute to achieve joint control with the slab outlet temperature. This can reduce the hysteresis of the system control by at least 1s. At the same time, it can also preliminarily determine whether the cooling system steady flow abnormality or the billet drawing system traction abnormality is to alert the supervisory personnel.

[0015] 2. The present invention obtains the temperature difference between the initial and outlet of a certain point in the metal melt according to the drawing speed, and uses this temperature difference as the correction temperature difference. The temperature difference at the starting and outlet of the slab engraved at the same time is compared to obtain a correction coefficient, and the coolant flow rate is adjusted in time with the correction coefficient, so as to achieve the actual temperature difference between the starting and ending points of the slab close to the target temperature difference, thereby improving the temperature control accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the process principle of the present invention; Figure 2 This is a logic diagram of the joint control of multiple temperature parameters of the present invention; Figure 3 This is a control diagram of the correction cooling system of the present invention.

[0017] In the figure: 1. hot mold; 2. copper melting furnace; 3. aluminum melting furnace; 4. insulation device; 5. crystallizer; 6. traction machine; 7. first thermocouple; 8. second thermocouple; 9. third thermocouple; 10. fourth thermocouple; 11. fifth thermocouple. DETAILED DESCRIPTION

[0018] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0019] See also Figure 1 A continuous casting device for processing copper-aluminum composite plates and strips includes a hot mold 1. A copper melting furnace 2 is provided at one end of the hot mold 1. An aluminum melting furnace 3 is provided at the top of the hot mold 1. The liquid inlet of the aluminum melting furnace 3 in the hot mold 1 is located above the inner liquid inlet of the copper melting furnace 2 in the hot mold 1. The copper melting furnace 2 heats the molten copper liquid into the hot mold 1, and the aluminum melting furnace 3 heats the molten aluminum liquid into the hot mold 1. An insulation device 4 is also provided on the hot mold 1. After the molten metal in the copper melting furnace 2 is fed in, the insulation device 4 keeps it warm. A crystallizer 5 is provided on the outside of the other end of the hot mold 1. The crystallizer 5 is used to rapidly cool the outlet section of the hot mold 1, so that the hot molten metal in the hot mold 1 gradually cools and solidifies. A traction machine 6 is provided on the outside of the other end of the hot mold 1. The traction machine 6 is used to slowly pull out the solidified metal in the outlet section of the hot mold 1 to form a slab. A first thermocouple 7 is provided in the hot mold 1 and near the confluence of the copper melting furnace 2 and the aluminum melting furnace 3. The first thermocouple 7 is used to obtain the temperature parameters at this point in real time. A second thermocouple 8 is provided near the outlet end of the hot mold 1. The second thermocouple 8 is used to obtain the real-time temperature parameters of the slab at the outlet of the hot mold 1.

[0020] The above is the process principle and structure of the traditional copper-aluminum composite plate and strip continuous casting device.

[0021] In the present application, a third thermocouple 9 and a fourth thermocouple 10 are respectively provided at the inlet and outlet ends of the crystallizer 5. The third thermocouple 9 is used to obtain the temperature parameters of the liquid inlet end of the crystallizer 5 in real time, and the fourth thermocouple 10 is used to obtain the temperature parameters of the liquid outlet end of the crystallizer 5 in real time. Under normal and stable working conditions, the traction speed of the slab by the traction machine 6 is stable, the inlet temperature detected at the first thermocouple 7 is constant, and the coolant circulation in the crystallizer 5 is constant. Therefore, the temperature difference between the third thermocouple 9 and the fourth thermocouple 10 is constant and changes with the increase of the circulation flow rate, that is, there is a rated corresponding relationship between the circulation flow rate and the temperature difference between the third thermocouple 9 and the fourth thermocouple 10.

[0022] Since the circulating liquid flow rate in the crystallizer 5 is higher than the pulling speed of the slab, the temperature difference between the inlet and outlet of the circulating liquid in the crystallizer 5 is used to replace the temperature difference between the slab at the outlet of the crystallizer 5 and the rated temperature, which can more timely feedback the temperature change. The time advance caused by the travel speed difference between the circulating liquid and the slab per unit time is the timeliness optimization after the two are replaced.

[0023] Furthermore, based on the temperature parameters of the slab outlet section, combined with the aforementioned determination of the circulating fluid temperature difference, if the circulating fluid temperature difference is normal, it indicates that the total heat supply that the circulating fluid in the crystallizer 5 can absorb is constant when the slab passes through the crystallizer 5 (i.e., the heat supply is supersaturated). At this point, the temperature parameters of the slab outlet section are further determined. If normal, the equipment is operating normally. If abnormal, the slab pulling speed may be too fast, causing the slab temperature parameters at the outlet to rise. This is because if the pulling speed is too slow (compared to normal operating conditions), that is, the solidification section stays in the crystallizer 5 longer than normal, then the heat absorbed by the circulating fluid fluctuates, and the circulating fluid temperature difference changes. Based on this, a joint determination can be achieved, on the one hand, timely adjusting the feedback system parameters, and on the other hand, determining the cause of some abnormalities, making timely adjustments, and notifying relevant personnel for on-site inspections.

[0024] The following is a parameterized description of the above process: See Figure 1 and Figure 2 First, the first thermocouple 7, the second thermocouple 8, the third thermocouple 9, and the fourth thermocouple 10 respectively obtain the corresponding ingot (the "ingot" and "slab" used in this application are the same terms) starting section temperature T1, ingot outlet section temperature T2, coolant inlet temperature K1, and coolant outlet temperature K2, and calculate the working temperature difference of the coolant (K2-K1). The temperature difference corresponding to the current circulating liquid flow rate is compared to determine whether it is abnormal. If the temperature difference is abnormal, the coolant flow rate is adjusted. Among them, if the temperature difference becomes larger, it means that a circulation section absorbs high heat, the circulation flow rate is slow, the residence time in the crystallizer 5 is long, the unit volume of circulating liquid takes away more heat, the temperature rise is high, and the temperature difference is large; if the temperature difference becomes smaller, it means that a circulation section absorbs low heat, the circulation flow rate is fast, the residence time in the crystallizer 5 is short, the unit volume of circulating liquid takes away less heat, the temperature rise is low, and the temperature difference is small.

[0025] If the temperature difference of the coolant is normal, then the temperature T2 of the billet outlet section is further compared with the rated temperature. If normal, the equipment is operating normally and the current working state can be maintained; if abnormal, the billet pulling speed is too fast and the billet pulling speed is adjusted.

[0026] As the equipment runs for a long time, the coolant flow rate is controlled by the temperature difference. The accumulated error of the temperature difference control will cause the circulating fluid flow rate control to be disordered. This application proposes a correction method: See Figure 1 and Figure 3 Similarly, the first thermocouple 7, the second thermocouple 8, the third thermocouple 9, and the fourth thermocouple 10 respectively obtain the corresponding billet starting section temperature T1, billet outlet section temperature T2, coolant inlet temperature K1, and coolant outlet temperature K2. Here, the timestamps of T1 and T2 need to be recorded, that is, each temperature parameter is bound to a time point. For the current time tn , obtain T1 through the first thermocouple 7 and the second thermocouple 8 n 、T2 n , T1 n Indicates t n At this moment, the temperature of the initial section of the casting billet measured by the first thermocouple 7 is T2 n Indicates t n At this moment, the second thermocouple 8 measures the temperature of the billet outlet section, and then calls the billet t n-1 Time T1 n-1 , T1 n-1 Indicates t n-1 At this moment, the temperature of the starting section of the casting billet measured by the first thermocouple 7 is used to calculate the corrected temperature difference ΔTcorrection = T1 n-1 -T2 n , calculate the current temperature difference ΔT = T1 n -T2 n , calculate the correction coefficient η according to the following formula: η=(ΔT 矫 -ΔT 目 ) / ΔT 目 ; Adjust the coolant flow rate according to the correction coefficient. If η is a positive value, the actual temperature of the outlet section is too low and the circulating fluid takes away too much heat. The circulating cooling rate should be reduced according to the correction coefficient, otherwise it should be increased according to the correction coefficient.

[0027] More accurate correction parameters, T1 n-1 The value of is taken as reference to the current traction speed of the traction machine 6. Specifically, the rated distance between the first thermocouple 7 and the second thermocouple 8 is set to s, and the traction speed of the traction machine 6 is set to v. Then the time from the starting point to the end point of a certain section of the billet is t0=s / v, that is, t n Time and t n-1 The time difference between the two moments is set as t0, thus simulating the actual temperature difference ΔT at a certain point of the billet from the starting section to the exit section. 矫 , and the current detected temperature difference ΔT 目 is the target temperature difference. Therefore, η is a positive value, and the actual temperature difference ΔT 矫 Higher than the target temperature difference ΔT 目 , the actual temperature of the outlet section is too low, the circulating fluid takes away too much heat, and the circulating cooling rate should be reduced according to the correction coefficient; η is a negative value, the actual temperature difference ΔT 矫 Lower than the target temperature difference ΔT 目 , the actual outlet temperature is too high, the circulating fluid removes too little heat, and the circulating cooling rate needs to be increased by the correction factor. Of course, due to the accuracy of the equipment's detection parameters, the positive and negative values ​​may not be zero as the critical point, but rather a range around zero as the critical range. Values ​​exceeding the range are positive, and values ​​below the range are negative.

[0028] By adding a third thermocouple 9 and a fourth thermocouple 10 at both ends of the liquid inlet and outlet of the crystallizer 5 respectively, and using this to measure the temperature difference instead of the traditional parameter value of the temperature T2 of the outlet section of the ingot, the corresponding adjustment after the system obtains the parameters can be staggered in advance, which appropriately solves the defects of the original lag performance, thereby ensuring the accuracy of the temperature adjustment and having a significant impact on the bonding of the ingot interface layer.

[0029] Among them, in order to further improve the parameter accuracy, a fifth thermocouple 11 is provided at the outlet end of the crystallizer 5 and near the top of the aluminum material. The second thermocouple 8 and the fifth thermocouple 11 respectively obtain the outlet section temperature parameters near copper and aluminum. After the parameters are obtained, the average value is taken to assign a value to replace the parameter value of the original billet outlet section temperature T2. This can solve the temperature difference caused by the cooling difference of the bimetallic material, making the outlet section temperature parameters more representative.

Claims

1. A continuous casting device for processing copper-aluminum composite plates and strips, comprising a hot mold (1), a copper melting furnace (2) provided at one end of the hot mold (1), an aluminum melting furnace (3) provided at the top of the hot mold (1), a crystallizer (5) provided on the outside of the other end of the hot mold (1), and a traction machine (6) provided on the outside of the other end of the hot mold (1), characterized in that: A first thermocouple (7) is provided in the hot mold (1) and near the confluence of the copper melting furnace (2) and the aluminum melting furnace (3). The first thermocouple (7) is used to obtain the temperature parameter at the point in real time. A second thermocouple (8) is provided near the outlet end of the hot mold (1). The second thermocouple (8) is used to obtain the real-time temperature parameter of the slab at the outlet of the hot mold (1). A third thermocouple (9) and a fourth thermocouple (10) are provided at the inlet and outlet ends of the crystallizer (5), respectively. The third thermocouple (9) is used to obtain the temperature parameter of the liquid inlet end of the crystallizer (5) in real time. The fourth thermocouple (10) is used to obtain the temperature parameter of the liquid outlet end of the crystallizer (5) in real time. The temperature difference obtained by the third thermocouple (9) and the fourth thermocouple (10) is used to feedback control the circulating liquid flow rate of the crystallizer (5). If the temperature difference is greater than the rated value, the circulating flow rate is increased, and vice versa, the circulating flow rate of the crystallizer (5) is reduced.

2. The continuous casting device for processing copper-aluminum composite plates and strips according to claim 1, characterized in that: When the temperature difference is normal, the real-time temperature parameter obtained by the second thermocouple (8) is compared with the rated value. When normal, the current working state of the equipment is maintained. When abnormal, the traction speed of the traction machine (6) is adjusted.

3. The continuous casting device for processing copper-aluminum composite plates and strips according to claim 1, characterized in that: The circulating liquid flow rate of the crystallizer (5) is regularly corrected, and the correction method is as follows: The first thermocouple (7), the second thermocouple (8), the third thermocouple (9), and the fourth thermocouple (10) respectively obtain the corresponding billet starting section temperature T1, billet outlet section temperature T2, coolant inlet temperature K1, and coolant outlet temperature K2, and record the timestamps of T1 and T2. The current time t n , obtain T1 through the first thermocouple (7) and the second thermocouple (8) n 、T2 n , retrieve the casting billet t with the timestamp n-1 Time T1 n-1 , calculate the corrected temperature difference ΔTcorrect = T1 n-1 -T2 n , calculate the current temperature difference ΔT = T1 n -T2 n , calculate the correction coefficient η according to the following formula: η=(ΔT 矫 -ΔT 目 ) / ΔT 目 ; Adjust the coolant flow rate according to the correction factor.

4. The continuous casting device for processing copper-aluminum composite plates and strips according to claim 3, characterized in that: If η is a positive value, the cycle cooling rate should be reduced according to the correction factor, otherwise it should be increased according to the correction factor.

5. The continuous casting device for processing copper-aluminum composite plates and strips according to claim 3, characterized in that: The T1 n-1 The value of t is taken as the reference of the current traction speed of the traction machine (6). n Time and t n-1 The time difference is set as the time taken for the casting billet to move at the current pulling speed of the pulling machine (6).

6. The continuous casting device for processing copper-aluminum composite plates and strips according to claim 4, characterized in that: The positive and negative values ​​of η are in the range of 0 as the critical range, the value exceeding the range is positive, and the value below the range is negative.

7. The continuous casting device for processing copper-aluminum composite plates and strips according to claim 2, characterized in that: A fifth thermocouple (11) is provided at the outlet end of the crystallizer (5) and near the top of the aluminum material. The second thermocouple (8) and the fifth thermocouple (11) respectively obtain the outlet section temperature parameters near the copper and aluminum, and the average value of the two temperature parameters is taken to replace the original billet outlet section temperature T2 parameter value.

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