A roll shape prediction method for thermal contribution of electromagnetically controlled rolls

Abstract

The present invention provides a method for predicting the roll shape of the thermal contribution of an electromagnetically controlled roller, comprising: analyzing the multi-physical field characteristics of an electromagnetic rod, determining the position of the core heat source area of ​​the electromagnetic rod and the high-temperature points in the area; selecting temperature monitoring points according to the distribution of the core heat source area of ​​the electromagnetic rod; calculating the temperature rise power and temperature rise effect of the contact area of ​​electromagnetic rods of different forms; combining the temperature rise power of the contact area of ​​the electromagnetic rod, comparing the temperature monitoring results, and matching the thermal expansion capacity; calculating the heat source level of the contact area between the rollers according to the temperature rise effect of the contact area, and calculating the real-time distribution of the temperature field in the roller and the thermal expansion of the roller using the finite difference method; calculating the roller contact heat transfer coefficient after the thermal expansion change according to the corresponding relationship between the convexity control ability of the thermal expansion and the contact pressure between the rollers as the control progresses; putting the electromagnetically controlled rollers after the control into the production line, participating in the roller gap shape control, and performing coefficient adaptive adjustment. The present invention can realize the online accurate prediction of the electromagnetically controlled roller shape.

Description

Technical Field

[0001] The invention relates to the field of mechanical technology, and in particular to a method for predicting the thermal contribution roll shape of an electromagnetically controlled rolling roller. Background Art

[0002] Electromagnetic roll shape control technology is a dynamic roll shape control technology based on endogenous thermal hybrid drive. It can rely on the built-in magnetic thermal multi-physics field coupling drive element - electromagnetic rod to achieve micro-scale, multi-segment roll shape flexible control. As the core of its endogenous drive, the temperature rise effect, heat transfer capacity and thermal expansion level of the electromagnetic rod directly affect the formation of the electromagnetically controlled roll shape, and play a key role in the roll gap shape control effect of the plate shape electromagnetically controlled rolling mill.

[0003] At present, the industry has carried out a lot of research and development work on the structural form of electromagnetic rods, the type of electromagnetically controlled rollers, and external auxiliary temperature control strategies, but there are still large gaps in the monitoring and analysis of electromagnetically controlled roller shape. The inventor has applied for the invention patent "A visual sensing electromagnetically controlled roller shape monitoring device and method CN112517647A" and the invention patent "Electromagnetic controlled roller control ability comprehensive test platform and test method CN110508627A", respectively proposing non-contact and contact detection schemes for the roller shape of electromagnetically controlled rollers. Both can be used for the test research of electromagnetically controlled rollers, but cannot be applied to the online detection of such rollers. Taking into account the endogenous thermal bulging characteristics of the roller, traditional roller convexity detection methods such as "A method for compensating the original roll gap shape of the roller CN111438199A", "A method for quickly establishing the thermal convexity of the roller in the cold rolling process CN107661902A" and "Original roll gap setting method based on thermal convexity in ultra-thin strip rolling of cold rolling mill CN105013835A" mostly focus on the thermal convexity of the roller caused by the temperature field outside the roller, but it is difficult to predict the roller shape state of the electromagnetically controlled roller thermal contribution under endogenous thermal drive.

[0004] Therefore, there are the following problems in predicting the thermal contribution roll shape of electromagnetically controlled rolls:

[0005] 1. Traditional prediction methods tend to focus on the thermal crown of the roll caused by external heat input, but are not suitable for the endogenous thermal drive of the electromagnetically controlled roll;

[0006] 2. The comprehensive roll shape of the electromagnetically controlled roll includes the heat-contributed roll shape and the force-contributed roll shape. The heat-contributed roll shape is the roll thermal crown problem driven by the endogenous heat of the roll, while the force-contributed roll shape is the roll force-expanding problem driven by the endogenous force of the roll due to the thermal expansion of the internal components. Both need to be predicted and analyzed.

[0007] 3. The existing roll shape prediction methods of electromagnetically controlled rolling mills are mostly suitable for the technical trial stage, but are difficult to put into practical application. It is urgent to develop more targeted roll shape prediction methods. Summary of the invention

[0008] In view of the above problems, the purpose of the present invention is to provide a method for predicting the roll shape of the thermal contribution of an electromagnetically controlled rolling mill roll. The method can calibrate and predict the thermal contribution roll shape of such rolling mill rolls respectively, and realize comprehensive roll shape prediction and analysis according to the heat transfer structure characteristics of the electromagnetic rod, the characteristics of the heat generation area and the force expansion capability characteristics, so as to provide the rolling mill control system with more accurate roll shape information to facilitate its roll gap shape control.

[0009] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0010] A method for predicting the thermal contribution roll shape of an electromagnetically controlled rolling mill roll comprises the following steps:

[0011] Step 1: Determine the location of the core heat source area of ​​the electromagnetic rod and the high-temperature points in the area by analyzing the multi-physical field characteristics of the electromagnetic rod; the multi-physical field characteristics include magnetic flux form, electromagnetic parameters, structural type, and structural parameters;

[0012] Step 2: Select the temperature monitoring points according to the core heat source area distribution and multi-physical field characteristics of the electromagnetic rod;

[0013] Step 3: Calculate the temperature rise power and temperature rise effect of the contact area of ​​different types of electromagnetic rods according to the input electromagnetic parameters and structure type of the electromagnetic rod;

[0014] Step 4: Combine the temperature rise power of the contact area under the given electromagnetic parameters of various types of electromagnetic rods in step 3, compare the temperature monitoring results of step 2, and match the thermal expansion capacity;

[0015] Step 5: Calculate the heat source level in the contact area between the rollers according to the temperature rise effect in the contact area, calculate the real-time distribution of the temperature field in the roller and the thermal expansion of the roller using the finite difference method, obtain the thermal expansion roller curve, and then solve the secondary crown control ability and the fourth crown control ability of the thermal expansion of various forms of electromagnetic rods;

[0016] Step 6: As the control progresses, the electromagnetically controlled thermal expansion drive of the rollers causes the contact pressure in the contact area between the rollers to increase, and induces a change in the contact relationship between the rollers; based on the corresponding relationship between the convexity control capability of the thermal expansion and the contact pressure between the rollers, the roller contact heat transfer coefficient after the thermal expansion changes is calculated;

[0017] Step seven: put the electromagnetically controlled rolling mill rolls into production line to participate in the roll gap shape control and make coefficient adaptive adjustments.

[0018] Preferably, the step 1 specifically includes:

[0019] Step 1.1 Preliminarily determine the magnetic field distribution law of the electromagnetic rod according to the magnetic flux form of the electromagnetic rod, including longitudinal magnetic flux, transverse magnetic flux and single-conductor heating;

[0020] If it is a longitudinal magnetic flux, its spatial magnetic flux lines are concentrated at the core of the coil and converge at the induction heating area of ​​the longitudinal magnetic flux electromagnetic rod, while the outside is sparse; if it is a transverse magnetic flux, its spatial magnetic field is concentrated at the end of the contact area of ​​the transverse magnetic flux electromagnetic rod, and the external magnetic field can be ignored; if it is a single-conductor heating, the spatial magnetic field is the cylindrical area with the conductor as the central axis;

[0021] Step 1.2: According to the electromagnetic rod structure type and structural parameters, combined with the magnetic field distribution law around the electromagnetic rod in step 1.1, if it is longitudinal magnetic flux and the electromagnetic rod structure is magnetically concentrated, the core heat source area is located in the middle of the induction heating area, and the middle axis position is the high temperature point in the area; if it is longitudinal magnetic flux but the electromagnetic rod structure is not magnetically concentrated, the core heat source area is offset to the contact area of ​​the edge of the electromagnetic rod, and its offset from the middle of the induction heating area is l l-nm =f l-nm (η l-c / e ,J,f,l I ,R r ,R h ); if it is transverse magnetic flux, the core heat source area is located at the end of the transverse magnetic flux electromagnetic rod contact area, and the proximal part of the contact area axis is the high temperature point in the area; if it is single-conductor heating, the core heat source area is the hole wall perforated by the single-conductor, and the axial center of the hole wall is the high temperature point in the area;

[0022] Among them, η l-c / e is the diameter ratio of the contact area of ​​the side of the non-magnetic electromagnetic rod, J is the input current density, f is the input current frequency, l I is the length of the induction heating zone of the longitudinal flux electromagnetic rod, R r is the electromagnetically controlled roller radius, R h It is used to electromagnetically control the roller hole radius.

[0023] Preferably, the step 2 specifically includes:

[0024] Step 2.1 If the magnetic flux is longitudinal and the electromagnetic rod structure is focused, four sets of thermocouples are arranged at equal angles in the middle of the electromagnetic rod induction heating zone, and real-time data is collected and recorded as T l-m1 (t), T l-m2 (t), T l-m3 (t) and T l-m4 (t); and calculate its real-time output data as:

[0025] The weight coefficient

[0026] Step 2.2 If the magnetic flux is longitudinal but the electromagnetic rod structure is not magnetically concentrated, then at a distance of l from the middle of the electromagnetic rod induction heating zone l-nm Four groups of thermocouples are arranged at equal angles at the cross-section position for real-time data acquisition. The data recording and processing form is the same as step 2.1. The real-time data collected is recorded as T l-nm1 (t), T l-nm2 (t), T l-nm3 (t) and T l-nm4 (t), and calculate the real-time output data as:

[0027] The weight coefficient

[0028] Step 2.3 If it is transverse flux, a thermocouple is arranged on one side of the transverse flux electromagnetic rod, and the depth of the thermocouple is

[0029] The thermocouples are arranged in an array of five, wherein four thermocouples are arranged at equal angles, one thermocouple is installed at the axis of the electromagnetic rod, and the insertion depth of the thermocouple is 0.25 times the length of the contact area of ​​the electromagnetic rod; wherein the real-time data of the thermocouples in the four equal-angle arrays is recorded as T t-m1 (t), T t-m2 (t), T t-m3 (t) and T t-m4 (t), the real-time data of the thermocouple installed at the axis of the electromagnetic rod is recorded as Tt-z(t), and the real-time output data is calculated as:

[0030] The weight coefficient

[0031] Among them, ρ ES is the resistivity of the electromagnetic rod material, ν ES is the magnetic permeability of the electromagnetic rod material;

[0032] Step 2.4: If single-wire heating is used, four thermocouples are arranged at equal intervals between the single-wire layers. The insertion depth of the thermocouple is 0.25 times the length of the electromagnetic rod contact area. The thermocouple is pasted on the end face of the electromagnetic rod, and its real-time data is recorded as T s-m1 (t), T s-m2 (t), T s-m3 (t) and T s-m4 (t), and calculate the real-time output data as:

[0033] The weight coefficient

[0034] Preferably, the step three specifically includes:

[0035] Step 3.1 For the longitudinal flux electromagnetic rod, according to the characteristics of the longitudinal flux, calculate the temperature rise power P of the induction heating zone driven by the longitudinal flux induction coil. l-I and the heat transfer efficiency η between the induction heating zone and the contact zone l-IC , combined with the longitudinal flux electromagnetic rod structural characteristics, the influence function g l-structure (η l-a ,η l-r ) and the heat exchange power between the rollers P ECR-change , obtain the temperature rise power P of the contact area of ​​the longitudinal flux electromagnetic rod l-C ;

[0036] Among them, the temperature rise power of the induction heating zone driven by the longitudinal magnetic flux induction coil is calculated as:

[0037] a1 and a2 are the calculation coefficients of temperature rise power in the induction heating zone of the longitudinal magnetic flux electromagnetic rod; the heat transfer efficiency between the induction heating zone and the contact zone is calculated as: The temperature rise power of the longitudinal flux electromagnetic rod contact area is calculated as: P l-C =g l-structure (η l-a ,η l-r ) l-I -P ECR-change ; For the longitudinal flux electromagnetic rod, its axial structure ratio is calculated as Longitudinal structure ratio l c is the contact area length of the longitudinal flux electromagnetic bar;

[0038] Step 3.2 For the transverse flux electromagnetic rod, according to the characteristics of the transverse flux, calculate the temperature rise power P of the induction heating zone driven by the transverse flux induction coil. t-I The internal heat transfer efficiency η of the contact area t-IC , combined with the structural characteristics of the transverse flux electromagnetic rod, the influence coefficient η t-r Heat exchange power between rollers P ECR-change , obtain the temperature rise power P of the transverse flux electromagnetic rod contact area t-C ;

[0039] Among them, the temperature rise power of the induction heating zone driven by the transverse flux induction coil is calculated as:

[0040] a3 and a4 are the power calculation coefficients for the temperature rise in the induction heating zone of the transverse flux electromagnetic rod; for the transverse flux electromagnetic rod, its structural characteristics affect the coefficient The temperature rise power of the transverse flux electromagnetic rod contact area is calculated as P t-C =η t-IC η t-r P t-I -P ECR-change;

[0041] Step 3.3 For the electromagnetic rod structure with a single wire heating, calculate the heat generation rate P around the wire according to the induction heating characteristics of the single wire. s-I , combined with the average temperature influence coefficient η s-I Heat exchange power between rollers P ECR-change , obtain the temperature rise power P of the electromagnetic rod contact area under single wire heating s-C ;

[0042] Among them, the heat generation rate around the conductor a5 and a6 are the power calculation coefficients for the temperature rise of the electromagnetic rod induction heating zone under single wire heating; for the uniform temperature influence coefficient, it is calculated as n s is the number of holes in a single circumference, R s is the wire hole radius; the temperature rise power of the electromagnetic rod contact area heated by a single wire is calculated as P s-C =η s-I P s-I -P ECR-change .

[0043] Preferably, the step 4 specifically includes:

[0044] Step 4.1 Calculate the average temperature rise of the contact area based on the temperature rise power of the contact area

[0045] Among them, P w-C According to the magnetic flux form of the electromagnetic rod, P l-C , P t-C With P s-C , m is the mass of the contact area, c is the specific heat of the electromagnetic rod material;

[0046] Step 4.1.1 If |T r (t)-T w-m (t)|≤10K, the power calculation of the temperature rise in the contact area is consistent with the actual temperature rise, and the thermal expansion capacity can be further derived based on the power of the temperature rise in the contact area;

[0047] Step 4.1.2 If |T r (t)-T w-m (t)|>10K, there is an error between the temperature rise power of the contact area and the actual temperature rise effect. It is necessary to stop the regulation and check the coil status, external AC power supply, roller structure contact status and roller structure integrity status, and then regulate again and compare the electromagnetic rod temperature rise until step 4.1.1 is met;

[0048] Step 4.2 matches the relationship between the temperature rise power of the contact area and the thermal expansion driving capacity of the roller according to the magnetic flux form of the electromagnetic rod;

[0049] Step 4.2.1 If it is a longitudinal flux form or a transverse flux form, the contact area is a solid bulging structure. The secondary convexity control capability C of thermal bulging under the two flux forms can be directly calculated based on the contact area temperature rise power of the two electromagnetic rod flux forms. force-w2 =k w2 P w-C With the ability to adjust the fourth convexity

[0050] Step 4.2.2 If a single wire is heated, its contact area is not a solid bulging structure, and the corresponding relationship between the temperature rise power of the contact area and the thermal bulging driving capacity should take into account the weakening factor of the rigidity characteristics. Therefore, the secondary convexity control capacity C of the thermal bulging under this form is calculated. force-w2 =k w2 P′ s-C With the fourth convexity control capability C force-w4 =k w4 (P′ s-C ) 2 +k′ w4 P′ s-C +k″ w4 ;

[0051] in

[0052] Preferably, the step five specifically includes:

[0053] According to the temperature rise effect of the contact area, calculate the heat source level T of the contact area between the rollers ECR (t) = tP ECR-change R contact +T r (t), where R contact is the roller contact heat transfer coefficient; combined with the finite difference method, the real-time distribution of the temperature field inside the electromagnetically controlled roller and the thermal expansion of the roller can be calculated to obtain the thermal expansion roller shape curve f thermal (x) = b1x 4 +b2x 2 +b3, and then solve the secondary convexity control ability C of various types of electromagnetic rod thermal expansion thermal-w2 With the fourth convexity control capability C thermal-w4 .

[0054] Preferably, the step six specifically includes:

[0055] According to the corresponding relationship between the convexity control ability of thermal expansion and the contact pressure between the rollers, p cs =k cs C force-w2 Calculation of roller contact heat transfer coefficient after thermal expansion changes

[0056] Among them, pcs is the contact pressure between the rollers, k cs is the coordination coefficient between the thermal expansion crown and the contact pressure between the rollers, and p is the initial contact pressure between the rollers.

[0057] Preferably, the step seven specifically includes:

[0058] The electromagnetically regulated roller is put into production line and is involved in the roll gap shape control. The input amount of the electromagnetically regulated roller's roll gap secondary convexity control is C w2 =C force-w2 +C thermal-w2 , the input amount of the fourth convexity control is C w4 =C force-w4 +C thermal-w4 ;According to the thickness of the rolled plate, the control efficiency function of the electromagnetically controlled roller is obtained, and the roll gap shape curve is fitted f RPECT-rg (x) = c1x 4 +c2x 2 +c3, obtain the actual secondary crown control value C of the electromagnetically controlled roller p-w2 and the actual fourth-order convexity control value C p-w4 , compare the actual and calculated values ​​of the second and fourth order convexity control quantities, and make adaptive adjustments to the coefficients:

[0059] If |C w2 -C p-w2 |<10%C w2 And |C w4 -C p-w4 |<30%C w4 , it is considered that the actual control amount is consistent with the calculated amount, and the control can continue;

[0060] If |C w2 -C p-w2 |<10%C w2 , it indicates that there is a difference between the environmental heat transfer capacity of the electromagnetically controlled roller and the parameters of the prediction model, and increasing P in the pre-step ECR-change To the current value times;

[0061] If |C w4 -C p-w4 |<30%C w4 , it indicates that there is a difference between the axial temperature expansion capacity of the electromagnetically controlled roller and the parameters of the prediction model, and it is necessary to adjust the R in the pre-step contact or R c ' ontact To the current value times.

[0062] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0063] The method for predicting the roll shape of the thermal contribution of the electromagnetically controlled rolling roller provided by the present invention is based on the magneto-thermal bulging mechanism of the electromagnetically controlled rolling roller. Starting from the characteristics of endogenous driving, it decouples the magnetic-thermal-mechanical multi-physical field coupling mechanism, and can intuitively analyze the magnetic-thermal coupling effect between the electromagnetic induction of the coil and the temperature rise of the electromagnetic rod induction zone, the thermal conductivity effect between the electromagnetic rod induction zone and the bulging zone, and the thermal-mechanical coupling bulging effect of the electromagnetically controlled rolling roller, and then derive the corresponding relationship between the input parameters such as electromagnetic parameters, structural parameters and temperature control parameters and the comprehensive contribution roll shape of the electromagnetically controlled rolling roller, thereby realizing the online accurate prediction of the electromagnetically controlled roll shape, and expanding new research methods and ideas for the industrial application of this technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0065] Figure 1 It is the principle diagram of the roll shape prediction method of the thermal contribution of the electromagnetically controlled roll;

[0066] Figure 2 This is a schematic diagram of the temperature monitoring points in the core heat source area;

[0067] Figure 3 Schematic diagram of the temperature variation curve of the core heat source area of ​​the electromagnetic rod and the average temperature rise curve of the contact area in Example 1;

[0068] Figure 4 1 is a schematic diagram of a temperature curve of a heat source in a contact heat exchange zone between rollers in Example 1;

[0069] Figure 5 Schematic diagram of the temperature variation curve of the core heat source area of ​​the electromagnetic rod and the average temperature rise curve of the contact area in Example 2;

[0070] Figure 6 It is a schematic diagram of the temperature curve of the heat source in the contact heat exchange zone between rollers in the second embodiment. DETAILED DESCRIPTION

[0071] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0072] The embodiment of the present invention provides a method for predicting the roll shape of a thermal contribution of an electromagnetically controlled roll. Figure 1 As shown, the method comprises the following steps:

[0073] Step 1: Determine the location of the core heat source area of ​​the electromagnetic rod and the high-temperature points in the area by analyzing the multi-physical field characteristics of the electromagnetic rod; the multi-physical field characteristics include magnetic flux form, electromagnetic parameters, structural type, and structural parameters.

[0074] The step 1 specifically includes:

[0075] Step 1.1 Preliminarily determine the magnetic field distribution law of the electromagnetic rod according to the magnetic flux form of the electromagnetic rod, including longitudinal magnetic flux, transverse magnetic flux and single-conductor heating;

[0076] If it is a longitudinal magnetic flux, its spatial magnetic flux lines are concentrated at the core of the coil and converge at the induction heating area of ​​the longitudinal magnetic flux electromagnetic rod, while the outside is sparse; if it is a transverse magnetic flux, its spatial magnetic field is concentrated at the end of the contact area of ​​the transverse magnetic flux electromagnetic rod, and the external magnetic field can be ignored; if it is a single-conductor heating, the spatial magnetic field is the cylindrical area with the conductor as the central axis;

[0077] Step 1.2: According to the electromagnetic rod structure type and structural parameters, combined with the magnetic field distribution law around the electromagnetic rod in step 1.1, if it is longitudinal magnetic flux and the electromagnetic rod structure is magnetically concentrated, the core heat source area is located in the middle of the induction heating area, and the middle axis position is the high temperature point in the area; if it is longitudinal magnetic flux but the electromagnetic rod structure is not magnetically concentrated, the core heat source area is offset to the contact area of ​​the edge of the electromagnetic rod, and its offset from the middle of the induction heating area is l l-nm =f l-nm (η l-c / e ,J,f,l I ,R r ,R h ); if it is transverse magnetic flux, the core heat source area is located at the end of the transverse magnetic flux electromagnetic rod contact area, and the proximal part of the contact area axis is the high temperature point in the area; if it is single-conductor heating, the core heat source area is the hole wall perforated by the single-conductor, and the axial center of the hole wall is the high temperature point in the area;

[0078] Among them, η l-c / e is the diameter ratio of the contact area of ​​the side of the non-magnetic electromagnetic rod, J is the input current density, f is the input current frequency, l I is the length of the induction heating zone of the longitudinal flux electromagnetic rod, R r is the electromagnetically controlled roller radius, R h It is used to electromagnetically control the roller hole radius.

[0079] Step 2: Select the temperature monitoring points based on the core heat source area distribution and multi-physical field characteristics of the electromagnetic rod.

[0080] The step 2 specifically includes:

[0081] Step 2.1 If the magnetic flux is longitudinal and the electromagnetic rod structure is focused, four sets of thermocouples are arranged at equal angles in the middle of the electromagnetic rod induction heating zone, and real-time data is collected and recorded as T l-m1 (t), T l-m2 (t), T l-m3 (t) and T l-m4 (t); and calculate its real-time output data as:

[0082] The weight coefficient

[0083] Step 2.2 If the magnetic flux is longitudinal but the electromagnetic rod structure is not magnetically concentrated, then at a distance of l from the middle of the electromagnetic rod induction heating zone l-nm Four groups of thermocouples are arranged at equal angles at the cross-section position for real-time data acquisition. The data recording and processing form is the same as step 2.1. The real-time data collected is recorded as T l-nm1 (t), T l-nm2 (t), T l-nm3 (t) and T l-nm4 (t), and calculate the real-time output data as:

[0084] The weight coefficient

[0085] Step 2.3 If it is transverse flux, a thermocouple is arranged on one side of the transverse flux electromagnetic rod, and the depth of the thermocouple is

[0086] The thermocouples are arranged in an array of five, wherein four thermocouples are arranged at equal angles, one thermocouple is installed at the axis of the electromagnetic rod, and the insertion depth of the thermocouple is 0.25 times the length of the contact area of ​​the electromagnetic rod; wherein the real-time data of the thermocouples in the four equal-angle arrays is recorded as T t-m1 (t), T t-m2 (t), T t-m3 (t) and T t-m4 (t), the real-time data of the thermocouple installed at the axis of the electromagnetic rod is recorded as Tt-z(t), and the real-time output data is calculated as:

[0087] The weight coefficient

[0088] Among them, ρ ES is the resistivity of the electromagnetic rod material, ν ES is the magnetic permeability of the electromagnetic rod material;

[0089] Step 2.4: If single-wire heating is used, four thermocouples are arranged at equal intervals between the single-wire layers. The insertion depth of the thermocouple is 0.25 times the length of the electromagnetic rod contact area. The thermocouple is pasted on the end face of the electromagnetic rod, and its real-time data is recorded as T s-m1 (t), T s-m2 (t), T s-m3 (t) and T s-m4 (t), and calculate the real-time output data as:

[0090] The weight coefficient

[0091] Figure 2 Schematic diagram of the temperature monitoring points in the core heat source area of ​​various types of electromagnetic rods.

[0092] Step 3: Calculate the temperature rise power and temperature rise effect of the contact area of ​​different types of electromagnetic rods according to the input electromagnetic parameters and structure type of the electromagnetic rod.

[0093] The step three specifically includes:

[0094] Step 3.1 For the longitudinal flux electromagnetic rod, according to the characteristics of the longitudinal flux, calculate the temperature rise power P of the induction heating zone driven by the longitudinal flux induction coil. l-I and the heat transfer efficiency η between the induction heating zone and the contact zone l-IC , combined with the longitudinal flux electromagnetic rod structural characteristics, the influence function g l-structure (η l-a ,η l-r ) and the heat exchange power between the rollers P ECR-change , obtain the temperature rise power P of the contact area of ​​the longitudinal flux electromagnetic rod l-C ;

[0095] Among them, the temperature rise power of the induction heating zone driven by the longitudinal magnetic flux induction coil is calculated as:

[0096] a1 and a2 are the calculation coefficients of temperature rise power in the induction heating zone of the longitudinal magnetic flux electromagnetic rod; the heat transfer efficiency between the induction heating zone and the contact zone is calculated as: The temperature rise power of the longitudinal flux electromagnetic rod contact area is calculated as: P l-C =g l-structure (η l-a ,η l-r ) l-I -P ECR-change ; For the longitudinal flux electromagnetic rod, its axial structure ratio is calculated as Longitudinal structure ratio l c is the contact area length of the longitudinal flux electromagnetic bar;

[0097] Step 3.2 For the transverse flux electromagnetic rod, according to the characteristics of the transverse flux, calculate the temperature rise power P of the induction heating zone driven by the transverse flux induction coil. t-I The internal heat transfer efficiency η of the contact area t-IC , combined with the structural characteristics of the transverse flux electromagnetic rod, the influence coefficient η t-r Heat exchange power between rollers P ECR-change , obtain the temperature rise power P of the transverse flux electromagnetic rod contact area t-C ;

[0098] Among them, the temperature rise power of the induction heating zone driven by the transverse flux induction coil is calculated as:

[0099] a3 and a4 are the power calculation coefficients for the temperature rise in the induction heating zone of the transverse flux electromagnetic rod; for the transverse flux electromagnetic rod, its structural characteristics affect the coefficient The temperature rise power of the transverse flux electromagnetic rod contact area is calculated as P t-C =η t-IC η t-r P t-I -P ECR-change ;

[0100] Step 3.3 For the electromagnetic rod structure with a single wire heating, calculate the heat generation rate P around the wire according to the induction heating characteristics of the single wire. s-I , combined with the average temperature influence coefficient η s-I Heat exchange power between rollers P ECR-change , obtain the temperature rise power P of the electromagnetic rod contact area under single wire heating s-C ;

[0101] Among them, the heat generation rate around the conductor a5 and a6 are the power calculation coefficients for the temperature rise of the electromagnetic rod induction heating zone under single wire heating; for the uniform temperature influence coefficient, it is calculated as n s is the number of holes in a single circumference, R s is the wire hole radius; the temperature rise power of the electromagnetic rod contact area heated by a single wire is calculated as P s-C =η s- I P s-I -P ECR-change .

[0102] Step 4: Combine the temperature rise power of the contact area under the given electromagnetic parameters of various types of electromagnetic rods in step 3, compare with the temperature monitoring results of step 2, and match the thermal expansion capacity.

[0103] The step 4 specifically includes:

[0104] Step 4.1 Calculate the average temperature rise of the contact area based on the temperature rise power of the contact area

[0105] Among them, P w-C According to the magnetic flux form of the electromagnetic rod, P l-C , P t-C With P s-C , m is the mass of the contact area, c is the specific heat of the electromagnetic rod material;

[0106] Step 4.1.1 If |T r (t)-T w-m (t)|≤10K, the power calculation of the temperature rise in the contact area is consistent with the actual temperature rise, and the thermal expansion capacity can be further derived based on the power of the temperature rise in the contact area;

[0107] Step 4.1.2 If |T r (t)-T w-m (t)|>10K, there is an error between the temperature rise power of the contact area and the actual temperature rise effect. It is necessary to stop the regulation and check the coil status, external AC power supply, roller structure contact status and roller structure integrity status, and then regulate again and compare the electromagnetic rod temperature rise until step 4.1.1 is met;

[0108] Step 4.2 matches the relationship between the temperature rise power of the contact area and the thermal expansion driving capacity of the roller according to the magnetic flux form of the electromagnetic rod;

[0109] Step 4.2.1 If it is a longitudinal flux form or a transverse flux form, the contact area is a solid bulging structure. The secondary convexity control capability C of thermal bulging under the two flux forms can be directly calculated based on the contact area temperature rise power of the two electromagnetic rod flux forms. force-w2 =k w2 P w-C With the ability to adjust the fourth convexity

[0110] Step 4.2.2 If a single wire is heated, its contact area is not a solid bulging structure, and the corresponding relationship between the temperature rise power of the contact area and the thermal bulging driving capacity should take into account the weakening factor of the rigidity characteristics. Therefore, the secondary convexity control capacity C of the thermal bulging under this form is calculated. force-w2 =k w2 P′ s-C With the fourth convexity control capability C force-w4 =k w4 (P′ s-C ) 2 +k′ w4 P′ s-C +k″ w4 ;

[0111] in

[0112] Step 5. According to the temperature rise effect in the contact area, calculate the heat source level in the contact area between the rollers, use the finite difference method to calculate the real-time distribution of the temperature field in the roller and the thermal expansion of the roller, obtain the thermal expansion roller curve, and then solve the secondary convexity control ability and fourth convexity control ability of various forms of electromagnetic rod thermal expansion.

[0113] The step five specifically includes:

[0114] According to the temperature rise effect of the contact area, calculate the heat source level T of the contact area between the rollers ECR (t) = tP ECR-change R contact +T r (t), where R contact is the roller contact heat transfer coefficient; combined with the finite difference method, the real-time distribution of the temperature field inside the electromagnetically controlled roller and the thermal expansion of the roller can be calculated to obtain the thermal expansion roller shape curve f thermal (x) = b1x 4 +b2x 2 +b3, and then solve the secondary convexity control ability C of various types of electromagnetic rod thermal expansion thermal-w2 With the fourth convexity control capability C thermal-w4 .

[0115] Step 6: As the control process progresses, the electromagnetically controlled thermal expansion drive of the rolling roller causes the contact pressure in the contact area between the rollers to increase, and induces changes in the contact relationship between the rollers; based on the corresponding relationship between the convexity control ability of the thermal expansion and the contact pressure between the rollers, the roller contact heat transfer coefficient after the thermal expansion change is calculated.

[0116] The step six specifically includes:

[0117] According to the corresponding relationship between the convexity control ability of thermal expansion and the contact pressure between the rollers, p cs =k cs C force-w2 Calculation of roller contact heat transfer coefficient after thermal expansion changes

[0118] Among them, p cs is the contact pressure between the rollers, k cs is the coordination coefficient between the thermal expansion crown and the contact pressure between the rollers, and p is the initial contact pressure between the rollers.

[0119] Step seven: put the electromagnetically controlled rolling mill rolls into production line to participate in the roll gap shape control and make coefficient adaptive adjustments.

[0120] The step seven specifically includes:

[0121] The electromagnetically regulated roller is put into production line and is involved in the roll gap shape control. The input amount of the electromagnetically regulated roller's roll gap secondary convexity control is Cw2 =C force-w2 +C thermal-w2 , the input amount of the fourth convexity control is C w4 =C force-w4 +C thermal-w4 ;According to the thickness of the rolled plate, the control efficiency function of the electromagnetically controlled roller is obtained, and the roll gap shape curve is fitted f RPECT-rg (x) = c1x 4 +c2x 2 +c3, obtain the actual secondary crown control value C of the electromagnetically controlled roller p-w2 and the actual fourth-order convexity control value C p-w4 , compare the actual and calculated values ​​of the second and fourth order convexity control quantities, and make adaptive adjustments to the coefficients:

[0122] If |C w2 -C p-w2 |<10%C w2 And |C w4 -C p-w4 |<30%C w4 , it is considered that the actual control amount is consistent with the calculated amount, and the control can continue;

[0123] If |C w2 -C p-w2 |<10%C w2 , it indicates that there is a difference between the environmental heat transfer capacity of the electromagnetically controlled roller and the parameters of the prediction model, and increasing P in the pre-step ECR-change To the current value times;

[0124] If |C w4 -C p-w4 |<30%C w4 , it indicates that there is a difference between the axial temperature expansion capacity of the electromagnetically controlled roller and the parameters of the prediction model, and it is necessary to adjust the R in the pre-step contact or R′ contact To the current value times.

[0125] The present invention is implemented in the form of longitudinal flux electromagnetic rods and transverse flux electromagnetic rods.

[0126] Embodiment 1: This embodiment uses a fully concentrated longitudinal magnetic flux electromagnetic rod as an endogenous driving element of an electromagnetically controlled roller, and implements thermal contribution roll shape prediction according to the method of the present invention. The specific steps are as follows:

[0127] Step 1: Determine the location of the core heat source area of ​​the electromagnetic rod and the high-temperature points in the area by analyzing the magnetic flux form, structural type, structural parameters and electromagnetic parameters of the electromagnetic rod; because a longitudinal magnetic flux electromagnetic rod is used, its spatial magnetic flux lines are concentrated at the core position of the coil and mainly converge in the induction heating area of ​​the longitudinal magnetic flux electromagnetic rod, while the outside is sparse; because the electromagnetic rod has a magnetic concentrating structure, its core heat source area is located in the middle of the induction heating area, and the middle axis position is the regional high-temperature point.

[0128] Step 2: According to the distribution of the core heat source area and the characteristics of the longitudinal magnetic flux electromagnetic rod, four groups of thermocouples are arranged at equal angles in the middle of the electromagnetic rod induction heating area, and real-time data is collected and recorded. l-m1 (t), T l-m2 (t), T l-m3 (t) and T l-m4 (t);

[0129] The real-time output data is The weight coefficient Real-time output data such as Figure 3 shown.

[0130] Step 3: Based on the input magnetic parameters and structural characteristics of the longitudinal flux electromagnetic rod, the temperature rise power and its temperature rise effect in the contact area can be calculated; where the current density J is 4A / mm 2 , the current frequency f is 400Hz, the relative magnetic permeability ν ES =0.35, resistivity ρ ES 9.78×10 -5 Ω·mm, the temperature rise power calculation coefficient a1 of the longitudinal magnetic flux electromagnetic rod induction heating zone is 0.3 and a2 is 0.7; the length of the electromagnetic rod induction heating zone is l I is 25mm, and its radius R I 25mm; the length of the electromagnetic rod contact area l C is 50mm, and its radius R C 50mm;

[0131] Induction zone temperature rise power P l-I It can be calculated as 438W, and the heat transfer efficiency between the induction heating area and the contact area is η l-IC It can be calculated as 0.5, and the axial structure ratio η l-a It can be calculated as 0.5, the longitudinal structure ratio η l-r It can be calculated as 0.5, the longitudinal flux electromagnetic rod structure characteristic influence function g l-structure (0.5,0.5) can be calculated as 0.7, the heat transfer power between rollers P ECR-change The initial setting is 83W, the contact area temperature rise power P l-C It can be calculated as 223.6W.

[0132] Step 4: Combine the temperature rise power of the contact area under the given magnetic parameters of various electromagnetic rods in step 3, and compare the temperature monitoring results of step 2 first, and then perform thermal expansion capacity matching. Considering the initial temperature T0 is 293.15K, the average temperature rise curve of the contact area can be calculated as follows: Figure 3 As shown. Figure 3 The calculated value and temperature monitoring value of the average temperature rise in the middle contact zone are generally less than 10K, indicating that the power calculation results of the temperature rise in the contact zone are consistent with the actual temperature rise and can be used to derive the thermal bulging capacity;

[0133] According to the longitudinal magnetic flux form characteristics of the electromagnetic rod, the contact area temperature rise power is matched with the roller thermal expansion driving capacity. Considering that the expansion contact area of ​​the longitudinal magnetic flux electromagnetic rod is a solid expansion structure, the contact area temperature rise power can be directly matched, where k w2 The value is 0.3, k w4 The value is 0.00013, k′ w4 The value is 0.0091, k′ w ′4 is 0.405. Further, we can calculate C force-w2 67μm, C force-w4 It is 9.17μm.

[0134] Step 5: According to the temperature rise effect of the contact area, the heat source temperature curve of the contact heat exchange area between the rollers can be calculated, such as Figure 4 As shown. Combined with the finite difference method, the real-time distribution of the temperature field inside the electromagnetically controlled roller and the thermal expansion of the roller can be calculated to obtain the thermal expansion roller curve f thermal (x) = 0.78x 4 +2.85x 2 +0.99, and then solve the secondary convexity control ability C of electromagnetically controlled roller thermal expansion in this embodiment thermal-w2 21μm, fourth-order convexity control capability C thermal-w4 It is 5.8μm.

[0135] Step 6: As the control progresses, the electromagnetically controlled thermal expansion drive of the rollers causes the contact pressure in the contact area to increase significantly, and induces changes in the contact relationship between the rollers. According to the corresponding relationship between the convexity control ability of the thermal expansion and the contact pressure between the rollers, the contact pressure between the rollers can be calculated. cs is 206MPa; considering that the initial roller contact pressure p is about 137MPa and the initial roller heat transfer coefficient is 0.73, the roller heat transfer coefficient R after force bulging can be calculated c ' ontact =1.09.

[0136] Step 7: Put the electromagnetically controlled roller into the production line and make it participate in the roll gap shape control. The input amount of the electromagnetically controlled roller gap secondary convexity control C is recorded. w288μm, four-time convexity control input amount C w4 is 14.97 μm; the control efficiency function of the electromagnetically controlled roller is obtained according to the thickness of the rolled plate, and the roll gap shape curve is fitted according to f RPECT-rg (x) = 1.57x 4 +3.68x 2 +1.0367, obtain the actual secondary crown control value C of the electromagnetically controlled roller p-w2 86μm and the actual fourth-order convexity control amount C p-w4 is 12.6μm. Comparing the actual and calculated values ​​of the second and fourth convexity control values, |C w2 -C p-w2 |=2μm<10%C w2 =8μm, |C w4 -C p-w4 |=2.37μm<30%C w4 =4.491μm, indicating that the actual control amount is basically consistent with the calculated amount, and the control can continue.

[0137] Embodiment 2: This embodiment uses a transverse flux electromagnetic rod as an endogenous driving element of an electromagnetically controlled roller, and implements thermal contribution roller shape prediction according to the method of the present invention. The specific steps are as follows:

[0138] Step 1: Due to the use of transverse flux electromagnetic rods, its spatial magnetic field is affected by the magnetic focusing device and is concentrated at the end of the contact area of ​​the transverse flux electromagnetic rod, with almost no magnetic field outside; its core heat source area is located at the end of the contact area of ​​the transverse flux electromagnetic rod, and the proximal part of the axis of the contact area is the regional high temperature point.

[0139] Step 2: Arrange a thermocouple on one side of the transverse flux electromagnetic rod, with a depth of l t-m The thermocouples are arranged in an array of five, with four thermocouples arranged at equal angles, one thermocouple installed at the axis of the electromagnetic rod, and the insertion depth of a single thermocouple is 12.5 mm. The real-time data of the four thermocouples arranged at equal angles is recorded as T t-m1 (t), T t-m2 (t), T t-m3 (t) and T t-m4 (t), the real-time data of the thermocouple installed at the axis of the electromagnetic rod is recorded as T t-z (t);

[0140] And calculate the real-time output data as The weight coefficient Real-time output data such as Figure 5 The electromagnetic rod material and contact area parameters of this embodiment are the same as those of the first embodiment.

[0141] Step 3: The temperature rise power P of the induction heating part of the transverse flux electromagnetic rod contact area can be calculated t-I is 270W; according to the induction coil diameter R IC is 64 mm, the structural characteristic influence coefficient η can be calculated t-r is 0.64; according to the internal heat transfer efficiency η of the contact area t-IC is 0.93, the temperature rise power P in the contact area of ​​the transverse flux electromagnetic rod can be calculated t-C It is 77.7W.

[0142] Step 4: The initial temperature of the electromagnetically controlled roller in this embodiment is the same as that in the first embodiment. The average temperature rise curve of the contact area of ​​the transverse magnetic flux electromagnetic rod can be calculated as follows: Figure 5 shown; contrast Figure 5 The calculated value and temperature monitoring value of the average temperature rise in the middle contact zone are generally less than 10K, indicating that the power calculation results of the temperature rise in the contact zone are consistent with the actual temperature rise and can be used to derive the thermal bulging capacity;

[0143] According to the transverse magnetic flux form characteristics of the electromagnetic rod, the contact area temperature rise power is matched with the roller thermal bulging driving capacity. Considering that the contact area of ​​the transverse magnetic flux form is a solid bulging structure, the contact area temperature rise power can be directly matched, where k w2 The value is 0.3, k w4 The value is 0.00013, k′ w4 The value is 0.0091, k″ w4 The value is 0.405. Further, C force-w2 23.3μm, C force-w4 It is 1.7μm.

[0144] Step 5: Based on the temperature rise effect of the contact area, the heat source level of the contact area between the rollers can be calculated as follows: Figure 6 As shown. Combined with the finite difference method, the real-time distribution of the temperature field inside the electromagnetically controlled roller and the thermal expansion of the roller can be calculated to obtain the thermal expansion roller curve f thermal (x) = 0.000714x 4 +0.037x 2 +0.253, and then solve the secondary convexity control ability C of thermal expansion in this embodiment thermal-w2 3μm, fourth-order convexity control capability C thermal-w4 0.2μm.

[0145] Step 6: According to the corresponding relationship between the convexity control ability of force bulging and the contact pressure between the rollers, the contact pressure between the rollers p can be calculated. cs is 186MPa; considering that the initial roller contact pressure p is about 137MPa and the initial roller heat transfer coefficient is 0.73, the roller heat transfer coefficient R after force bulging can be calculated c 'ontact =0.99.

[0146] Step 7: Put the electromagnetically controlled roller into the production line and make it participate in the roll gap shape control. The input amount of the electromagnetically controlled roller gap secondary convexity control C is recorded. w2 26.3μm, four-time convexity control input amount C w4 is 1.9 μm; the control efficiency function of the electromagnetically controlled roller is obtained according to the thickness of the rolled plate, and the roll gap shape curve is fitted according to f RPECT-rg (x) = 0.00183x 4 +0.059x 2 +0.427, obtain the actual secondary crown control value C of the electromagnetically controlled roller p-w2 28μm and the actual fourth-order convexity control amount C p-w4 is 1.47μm. Comparing the actual and calculated values ​​of the second and fourth convexity control values, |C w2 -C p-w2 |=1.7μm<10%C w2 =2.63μm, |C w4 -C p-w4 |=0.43μm<30%C w4 =0.57μm, indicating that the actual control amount is basically consistent with the calculated amount, and the control can continue.

[0147] In summary, the new thermal contribution roll shape prediction method proposed in the present invention can decouple the magnetic-thermal-mechanical multi-physical field coupling mechanism based on the characteristics of endogenous driving, and intuitively analyze the magnetic-thermal coupling effect, thermal conductivity effect, and thermal-mechanical coupling bulging effect, which expands new research methods and ideas for the industrial application of this technology.

[0148] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.

[0149] References in the specification to "one embodiment", "an embodiment", "an exemplary embodiment", "some embodiments", etc. indicate that the described embodiments may include a particular feature, structure, or characteristic, but not every embodiment may include the particular feature, structure, or characteristic. In addition, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, it should be within the knowledge of a person skilled in the relevant art to implement such feature, structure, or characteristic in conjunction with other embodiments (whether or not explicitly described).

[0150] The present invention covers any substitution, modification, equivalent method and scheme made on the essence and scope of the present invention. In order to make the public have a thorough understanding of the present invention, specific details are described in detail in the following preferred embodiments of the present invention, but those skilled in the art can fully understand the present invention without the description of these details. In addition, in order to avoid unnecessary confusion about the essence of the present invention, well-known methods, processes, procedures, components and circuits are not described in detail.

[0151] A person skilled in the art will appreciate that all or part of the steps in the above-mentioned embodiment method can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc.

[0152] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for predicting the thermal contribution of an electromagnetically controlled roller, characterized in that: The following steps are involved: Step 1: Determine the location of the core heat source area of ​​the electromagnetic rod and the high-temperature points in the area by analyzing the multi-physical field characteristics of the electromagnetic rod; the multi-physical field characteristics include magnetic flux form, electromagnetic parameters, structural type, and structural parameters; Step 2: Select the temperature monitoring points according to the core heat source area distribution and multi-physical field characteristics of the electromagnetic rod; Step 3: Calculate the temperature rise power and temperature rise effect of the contact area of ​​different types of electromagnetic rods according to the input electromagnetic parameters and structure type of the electromagnetic rod; Step 4: Combine the temperature rise power of the contact area under the given electromagnetic parameters of various types of electromagnetic rods in step 3, compare the temperature monitoring results of step 2, and match the thermal expansion capacity; Step 5: Calculate the heat source level in the contact area between the rollers according to the temperature rise effect in the contact area, calculate the real-time distribution of the temperature field in the roller and the thermal expansion of the roller using the finite difference method, obtain the thermal expansion roller curve, and then solve the secondary crown control ability and the fourth crown control ability of the thermal expansion of various forms of electromagnetic rods; Step 6: As the control progresses, the electromagnetically controlled thermal expansion drive of the rollers causes the contact pressure in the contact area between the rollers to increase, and induces a change in the contact relationship between the rollers; based on the corresponding relationship between the convexity control capability of the thermal expansion and the contact pressure between the rollers, the roller contact heat transfer coefficient after the thermal expansion changes is calculated; Step seven: put the electromagnetically controlled rolling mill rolls into production line to participate in the roll gap shape control and make coefficient adaptive adjustments.

2. The thermal contribution roll shape prediction method according to claim 1, characterized in that: The step 1 specifically includes: Step 1.1 Preliminarily determine the magnetic field distribution law of the electromagnetic rod according to the magnetic flux form of the electromagnetic rod, including longitudinal magnetic flux, transverse magnetic flux and single-conductor heating; If it is a longitudinal magnetic flux, its spatial magnetic flux lines are concentrated at the core of the coil and converge at the induction heating area of ​​the longitudinal magnetic flux electromagnetic rod, while the outside is sparse; if it is a transverse magnetic flux, its spatial magnetic field is concentrated at the end of the contact area of ​​the transverse magnetic flux electromagnetic rod, and the external magnetic field is negligible; if it is a single-conductor heating, the spatial magnetic field is the cylindrical area with the conductor as the central axis; Step 1.2: According to the electromagnetic rod structure type and structural parameters, combined with the magnetic field distribution law around the electromagnetic rod in step 1.1, if it is longitudinal magnetic flux and the electromagnetic rod structure is magnetically concentrated, the core heat source area is located in the middle of the induction heating area, and the middle axis position is the high temperature point in the area; if it is longitudinal magnetic flux but the electromagnetic rod structure is not magnetically concentrated, the core heat source area is offset to the contact area of ​​the edge of the electromagnetic rod, and its offset from the middle of the induction heating area is l l-nm =f l-nm (η l-c / e ,J,f,l I ,R r ,R h ); if it is transverse magnetic flux, the core heat source area is located at the end of the transverse magnetic flux electromagnetic rod contact area, and the proximal part of the contact area axis is the high temperature point in the area; if it is single-conductor heating, the core heat source area is the hole wall perforated by the single-conductor, and the axial center of the hole wall is the high temperature point in the area; Among them, η l-c / e is the diameter ratio of the contact area of ​​the side of the non-magnetic electromagnetic rod, J is the input current density, f is the input current frequency, l I is the length of the induction heating zone of the longitudinal flux electromagnetic rod, R r is the electromagnetically controlled roller radius, R h It is used to electromagnetically control the roller hole radius.

3. The thermal contribution roll shape prediction method according to claim 1, characterized in that: The step 2 specifically includes: Step 2.1 If the magnetic flux is longitudinal and the electromagnetic rod structure is focused, four sets of thermocouples are arranged at equal angles in the middle of the electromagnetic rod induction heating zone, and real-time data is collected and recorded as T l-m1 (t), T l-m2 (t), T l-m3 (t) and T l-m4 (t); and calculate its real-time output data as: The weight coefficient Step 2.2 If the magnetic flux is longitudinal but the electromagnetic rod structure is not magnetically concentrated, then at a distance of l from the middle of the electromagnetic rod induction heating zone l-nm Four groups of thermocouples are arranged at equal angles at the cross-section position for real-time data acquisition. The data recording and processing form is the same as step 2.

1. The real-time data collected is recorded as T l-nm1 (t), T l-nm2 (t), T l-nm3 (t) and T l-nm4 (t), and calculate the real-time output data as: The weight coefficient Step 2.3 If it is transverse flux, a thermocouple is arranged on one side of the transverse flux electromagnetic rod, and the depth of the thermocouple is The thermocouples are arranged in an array of five, wherein four thermocouples are arranged at equal angles, one thermocouple is installed at the axis of the electromagnetic rod, and the insertion depth of the thermocouple is 0.25 times the length of the contact area of ​​the electromagnetic rod; wherein the real-time data of the thermocouples in the four equal-angle arrays is recorded as T t-m1 (t), T t-m2 (t), T t-m3 (t) and T t-m4 (t), the real-time data of the thermocouple installed at the axis of the electromagnetic rod is recorded as T t-z (t), and calculate the real-time output data as: The weight coefficient Among them, ρ ES is the resistivity of the electromagnetic rod material, ν ES is the magnetic permeability of the electromagnetic rod material; Step 2.4: If single-wire heating is used, four thermocouples are arranged at equal intervals between the single-wire layers. The insertion depth of the thermocouple is 0.25 times the length of the electromagnetic rod contact area. The thermocouple is pasted on the end face of the electromagnetic rod, and its real-time data is recorded as T s-m1 (t), T s-m2 (t), T s-m3 (t) and T s-m4 (t), and calculate the real-time output data as: The weight coefficient 4. The thermal contribution roll shape prediction method according to claim 1, characterized in that: The step three specifically includes: Step 3.1 For the longitudinal flux electromagnetic rod, according to the characteristics of the longitudinal flux, calculate the temperature rise power P of the induction heating zone driven by the longitudinal flux induction coil. l-I and the heat transfer efficiency η between the induction heating zone and the contact zone l-IC , combined with the longitudinal flux electromagnetic rod structural characteristics, the influence function g l-structure (η l-a ,η l-r ) and the heat exchange power between the rollers P ECR-change , obtain the temperature rise power P of the contact area of ​​the longitudinal flux electromagnetic rod l-C ; Among them, the temperature rise power of the induction heating zone driven by the longitudinal magnetic flux induction coil is calculated as: a1 and a2 are the calculation coefficients of temperature rise power in the induction heating zone of the longitudinal magnetic flux electromagnetic rod; the heat transfer efficiency between the induction heating zone and the contact zone is calculated as: The temperature rise power of the longitudinal flux electromagnetic rod contact area is calculated as: P l-C =g l-structure (η l-a ,η l-r ) l-I -P ECR-change ; For the longitudinal flux electromagnetic rod, its axial structure ratio is calculated as Longitudinal structure ratio l c is the contact zone length of the longitudinal flux electromagnetic bar; Step 3.2 For the transverse flux electromagnetic rod, according to the characteristics of the transverse flux, calculate the temperature rise power P of the induction heating zone driven by the transverse flux induction coil. t-I The internal heat transfer efficiency η of the contact area t-IC , combined with the structural characteristics of the transverse flux electromagnetic rod, the influence coefficient η t-r Heat exchange power between rollers P ECR-change , obtain the temperature rise power P of the transverse flux electromagnetic rod contact area t-C ; Among them, the temperature rise power of the induction heating zone driven by the transverse flux induction coil is calculated as: a3 and a4 are the power calculation coefficients for the temperature rise in the induction heating zone of the transverse flux electromagnetic rod; for the transverse flux electromagnetic rod, its structural characteristics affect the coefficient The temperature rise power of the transverse flux electromagnetic rod contact area is calculated as P t-C =η t-IC η t-r P t-I -P ECR-change ; Step 3.3 For the electromagnetic rod structure with a single wire heating, calculate the heat generation rate P around the wire according to the induction heating characteristics of the single wire. s-I , combined with the average temperature influence coefficient η s-I Heat exchange power between rollers P ECR-change , obtain the temperature rise power P of the electromagnetic rod contact area under single wire heating s-C ; Among them, the heat generation rate around the conductor a5 and a6 are the power calculation coefficients for the temperature rise of the electromagnetic rod induction heating zone under single wire heating; for the uniform temperature influence coefficient, it is calculated as n s is the number of holes in a single circumference, R s is the wire hole radius; the temperature rise power of the electromagnetic rod contact area heated by a single wire is calculated as P s-C =η s-I P s-I -P ECR-change .

5. The thermal contribution roll shape prediction method according to claim 1, characterized in that: The step 4 specifically includes: Step 4.1 Calculate the average temperature rise of the contact area based on the temperature rise power of the contact area Among them, P w-C According to the magnetic flux form of the electromagnetic rod, P l-C , P t-C With P s-C , m is the mass of the contact area, c is the specific heat of the electromagnetic rod material; Step 4.1.1 If |T r (t)-T w-m (t)|≤10K, the power calculation of the temperature rise in the contact area is consistent with the actual temperature rise, and the thermal expansion capacity is further derived based on the power of the temperature rise in the contact area; Step 4.1.2 If |T r (t)-T w-m (t)|>10K, there is an error between the temperature rise power of the contact area and the actual temperature rise effect. It is necessary to stop the regulation and check the coil status, external AC power supply, roller structure contact status and roller structure integrity status, and then regulate again and compare the electromagnetic rod temperature rise until step 4.1.1 is met; Step 4.2 matches the relationship between the temperature rise power of the contact area and the thermal expansion driving capacity of the roller according to the magnetic flux form of the electromagnetic rod; Step 4.2.1 If it is a longitudinal flux form or a transverse flux form, the contact area is a solid bulging structure. Directly calculate the secondary convexity control capacity C of thermal bulging under the two flux forms according to the contact area temperature rise power of the two electromagnetic rod flux forms. force-w2 =k w2 P w-C With the ability to adjust the fourth convexity Step 4.2.2 If a single wire is heated, its contact area is not a solid bulging structure, and the corresponding relationship between the temperature rise power of the contact area and the driving capacity of the thermal bulging should take into account the weakening factor of the rigidity characteristics. Therefore, the secondary convexity control capacity C of the thermal bulging under this form is calculated. force-w2 =k w2 P s ' -C With the fourth convexity control capability C force-w4 =k w4 (P s ' -C ) 2 +k′ w4 P s ' -C +k′ w '4; in 6. The thermal contribution roll shape prediction method according to claim 1, characterized in that: The step five specifically includes: According to the temperature rise effect of the contact area, calculate the heat source level T of the contact area between the rollers ECR (t) = tP ECR-change R contact +T r (t), where R contact is the roller contact heat transfer coefficient; combined with the finite difference method, the real-time distribution of the temperature field inside the electromagnetically controlled roller and the thermal expansion of the roller can be calculated to obtain the thermal expansion roller shape curve f thermal (x) = b1x 4 +b2x 2 +b3, and then solve the secondary convexity control ability C of various forms of electromagnetic rod thermal expansion thermal-w2 With the fourth convexity control capability C thermal-w4 .

7. The thermal contribution roll shape prediction method according to claim 6, characterized in that: The step six specifically includes: According to the corresponding relationship between the convexity control ability of thermal expansion and the contact pressure between the rollers, p cs =k cs C force-w2 Calculation of roller contact heat transfer coefficient after thermal expansion changes Among them, p cs is the contact pressure between the rollers, k cs is the coordination coefficient between the thermal expansion crown and the contact pressure between the rollers, and p is the initial contact pressure between the rollers.

8. The thermal contribution roll shape prediction method according to claim 7, characterized in that: The step seven specifically includes: The electromagnetically regulated roller is put into production line and is involved in the roll gap shape control. The input amount of the electromagnetically regulated roller's roll gap secondary convexity control is C w2 =C force-w2 +C thermal-w2 , the input amount of the fourth convexity control is C w4 =C force-w4 +C thermal-w4 ;According to the thickness of the rolled plate, the control efficiency function of the electromagnetically controlled roller is obtained, and the roll gap shape curve is fitted f RPECT-rg (x) = c1x 4 +c2x 2 +c3, obtain the actual secondary crown control value C of the electromagnetically controlled roller p-w2 and the actual fourth-order convexity control value C p-w4 , compare the actual and calculated values ​​of the second and fourth order convexity control quantities, and make adaptive adjustments to the coefficients: If |C w2 -C p-w2 |<10%C w2 And |C w4 -C p-w4 |<30%C w4 , it is considered that the actual control amount is consistent with the calculated amount, and the control continues; If |C w2 -C p-w2 |<10%C w2 , it indicates that there is a difference between the environmental heat transfer capacity of the electromagnetically controlled roller and the parameters of the prediction model. ECR-change To the current value times; If |C w4 -C p-w4 |<30%C w4 , it indicates that there is a difference between the axial temperature expansion capacity of the electromagnetically controlled roller and the parameters of the prediction model, and it is necessary to adjust the R in step 6 contact or R c ' ontact To the current value times.

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