Electromagnetic heating device and control method thereof

Abstract

The application provides an electromagnetic heating device and a control method thereof. The electromagnetic heating device comprises K groups of induction heating units. Each group of induction heating units comprises two first induction coils located above a slab passage and two second induction coils located below the slab passage. In a first direction, the two first induction coils and the two second induction coils of each group of induction heating units are arranged correspondingly. The two first induction coils are arranged adjacently on the slab, and the two second induction coils are arranged adjacently below the slab. The coil plane of each induction coil is perpendicular to the first direction. The control units of the induction coils located at the same relative position in each group of induction heating units are the same control unit, and the control units of the induction coils located at different relative positions in each group of induction heating units are different control units, or the control units of the induction coils are independently arranged.

Description

Technical Field

[0001] This invention relates to an electromagnetic heating device and its control method, and more particularly to an electromagnetic heating device and its control method for metal plates. Background Technology

[0002] With the advancement of technology, the production of special-performance steel plates, such as high-strength steel with excellent weldability, steel for high-rise buildings, and steel for large ships, using continuous casting and rolling processes has become a sought-after goal. However, rolling continuously cast billets into strips of different shapes and specifications requires reheating of the billets before further processing. Rapid online heating of the strip has a significant impact on the material microstructure transformation of the strip and is crucial to its final properties. Therefore, achieving rapid online heating of the strip is one of the key technologies for obtaining high-performance special-purpose strips.

[0003] Traditional gas-fired or resistance wire radiant tube heating technologies are gradually being phased out due to their high environmental pollution and low heating efficiency. Induction heating technology, which utilizes the Joule heating effect of eddy currents in a metal conductor to heat the metal itself, has rapidly developed in industrial production due to its advantages such as fast heating speed, high efficiency, precise temperature control, good uniformity, and low pollution. Based on the type of magnetic field generated by the induction heater, it can be divided into longitudinal magnetic fields and transverse magnetic fields, both of which are used in metal sheets. In longitudinal magnetic field induction heating, the magnetic field lines are parallel to the upper and lower surfaces of the metal sheet, and the induced eddy currents are equal in magnitude but opposite in direction at the center of the slab. Therefore, the eddy currents at the center cancel each other out, resulting in lower heating efficiency for longitudinal magnetic field induction heating on ultra-thin sheets and strips (the thinner the slab, the more the eddy currents on the upper and lower surfaces cancel each other out, and the lower the heating efficiency). In transverse magnetic field induction, the magnetic field lines generated by the induction heater are perpendicular to the surface of the metal sheet being heated, and the eddy currents at the center of the sheet do not cancel each other out, resulting in high energy utilization. However, transverse magnetic eddy currents tend to accumulate at the edges of the metal sheet, causing edge overheating.

[0004] To achieve continuous, efficient, and uniform heating of metal sheets of different specifications and sizes on the same production line, patents CN 104775021A and CN 111278182A employ a combination of longitudinal and transverse magnetic induction heaters to solve the problem of uniform heating of slabs of different specifications. However, both their transverse and longitudinal magnetic heating structures are specialized structures, and for different types of slabs, the same inductor cannot switch between transverse and longitudinal magnetic heating modes, resulting in poor adaptability. Patent CN113923808A uses coils arranged at different positions on the slab being heated to eliminate the problem of overheating at the edges in the width direction of the slab, thus ensuring the uniformity of heating temperature. This solution requires high precision and is structurally complex and difficult to implement. Summary of the Invention

[0005] The purpose of this invention is to address the problem that the sensors in existing induction heating devices using a combination of transverse and longitudinal magnetic heating cannot switch between transverse and longitudinal magnetic heating modes, resulting in poor adaptability. This invention provides an electromagnetic heating device and its control method.

[0006] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0007] An electromagnetic heating device, defining the channel through which the slab passes as the slab channel, defining a first direction as the height / width direction of the slab channel, and defining a second direction as the width / height direction of the slab channel;

[0008] The electromagnetic heating device is characterized in that it comprises K groups of induction heating units, where K ≥ 1; when K ≥ 2, the K groups of induction heating units are spaced apart along the slab running direction; each group of induction heating units comprises two first induction coils and two second induction coils; the two first induction coils are located above the slab channel and are arranged adjacent to each other in the slab running direction; the two second induction coils are located below the slab channel and are arranged adjacent to each other in the slab running direction; in the first direction, the two first induction coils and the two second induction coils of each group of induction heating units are respectively arranged correspondingly; the coil plane of each induction coil is perpendicular to the first direction.

[0009] In this application, through the above-described configuration, the current of the induction coil can be controlled by the control unit. This allows for adjustment of the magnetic poles (N and S poles) of each induction coil as needed, thereby generating different magnetic fields (e.g., longitudinal or transverse magnetic) to heat the slab. This application enables convenient switching between longitudinal and transverse magnetic heating modes on the same production line using the same heating device.

[0010] In the above technical solution: the projection of each induction coil onto the slab plane (the coil plane is parallel to the upper surface of the slab, which is the upper surface of the slab in the top view of this embodiment) is composed of a first connecting segment, a second connecting segment, a third connecting segment, and a fourth connecting segment; the first connecting segment and the second connecting segment are arranged opposite to each other in the slab running direction; the third connecting segment and the fourth connecting segment are arranged opposite to each other in a second direction; one end of the first connecting segment and one end of the second connecting segment are connected to each other through the third connecting segment; the other end of the first connecting segment and the other end of the second connecting segment are connected to each other through the fourth connecting segment; the third connecting segment and / or the fourth connecting segment are bulging segments, and the shape formed by the bulging segments protrudes from the connection point of the bulging segment and the first connecting segment in a direction away from the second connecting segment, and from the connection point of the bulging segment and the second connecting segment in a direction away from the first connecting segment, and in the second direction protrudes to the side away from the area between the third connecting segment and the fourth connecting segment.

[0011] By including at least a bulging section in the induction coil, the bulging section disperses the eddy currents formed by the coil in the slab area (the area inside or near the slab) as the slab passes through the slab channel, reducing the effect of edge overheating caused by the concentration of eddy currents on the side of the slab (i.e., the edge of the slab).

[0012] In the above technical solution: both the first connecting segment and the second connecting segment are straight line segments parallel to the second direction;

[0013] The bulging section is an arc-shaped section, and the radius of curvature of the arc-shaped section is greater than half the distance between the first connecting section and the second connecting section; or

[0014] The bulging section forms a trapezoidal shape; or

[0015] The bulging section forms a rectangular shape.

[0016] In the above technical solution: the third connecting segment is a bulging segment, and the fourth connecting segment is a straight segment;

[0017] The third connecting segments of each induction coil in each group of induction heating units are located on the same side in the second direction, and the third connecting segments of each induction coil in each group of induction heating units are located on opposite sides in the second direction from the third connecting segments of each induction coil in the adjacent group of induction heating units; or

[0018] In each group of induction heating units, the third connecting segments corresponding to the two first induction coils are located on opposite sides in the second direction, while the third connecting segments corresponding to the first and second induction coils in each group of induction heating units are located on the same side in the second direction.

[0019] With the above arrangement, the number of third connecting sections corresponding to each induction coil in the electromagnetic heating device located on one side and the other side in the second direction (e.g., on the left and right sides in the width direction) is arranged more evenly, so that the heating effect on the slab is more uniform.

[0020] In the above technical solution: each group of induction heating units includes a mounting base, a first coil fixing frame for accommodating two first induction coils, and a second coil fixing frame for accommodating two second induction coils;

[0021] The first coil fixing frame is located above the second coil fixing frame;

[0022] The first coil fixing frame and the second coil fixing frame of each induction heating unit are respectively installed on the mounting base.

[0023] In the above technical solution: the mounting base of each group of induction heating units is also equipped with a first position adjustment mechanism and / or a second position adjustment mechanism; the first position adjustment mechanism is used to adjust the position of the first coil fixing frame and / or the second coil fixing frame in a first direction; the second position adjustment mechanism is used to adjust the position of the first coil fixing frame and / or the second coil fixing frame in a second direction.

[0024] With the above settings, when the size of the slab in the first direction is large, the spacing between the first induction coil and the second induction coil in the first direction can be adjusted by the first position adjustment mechanism to prevent the large slab from being unable to enter the channel or from colliding with the electromagnetic heating device and damaging the device. When the first induction coil and the second induction coil need to be repaired or maintained, the position of the first coil fixing frame and the second coil fixing frame in the second direction can be adjusted by the second position adjustment mechanism so that the corresponding first induction coil and second induction coil are aligned when they are not aligned, or the first coil fixing frame and the second coil fixing frame are staggered when the electromagnetic heating device is not working, thereby facilitating repair or maintenance.

[0025] In the above technical solution, the control unit of the induction coil located at the same relative position in each group of induction heating units is the same control unit, and the control unit of the induction coil located at different relative positions in each group of induction heating units is a different control unit, or the control unit of each induction coil in each group of induction heating units is set independently.

[0026] In the above technical solution: the mounting base is also equipped with a U-shaped magnetic field shielding structure; in the second direction, the opening of the U-shaped magnetic field shielding structure faces the slab located in the slab channel and is adapted to the size of the slab.

[0027] Through the above settings, the U-shaped magnetic field shielding structure is used to protect the side of the slab, shielding part or all of the magnetic field on the side of the slab, thereby reducing the impact of side overheating caused by eddy currents concentrating on the side of the slab.

[0028] In the above technical solution: the U-shaped magnetic field shielding structure includes a shielding structure shell, the shielding structure shell is made of conductive material, a flow channel is formed inside the shielding structure shell, and the flow channel contains a liquid cooling medium.

[0029] The above settings can shield the magnetic field, cool the shielding structure shell, and also cool the sides to reduce the impact of side overheating.

[0030] In the above technical solution: the first coil fixing frame and the second coil fixing frame are respectively fixedly connected to the first telescopic mechanism fixing seat and the second telescopic mechanism fixing seat; the first induction coil is wound on the outside of the corresponding first iron core, and the second induction coil is wound on the outside of the corresponding second iron core; the projected size of the first iron core in the second direction is smaller than the projected size of the inner circumferential area of ​​the corresponding first induction coil in the second direction; the projected size of the second iron core in the second direction is smaller than the projected size of the inner circumferential area of ​​the corresponding second induction coil in the second direction; a first telescopic mechanism is connected between each first iron core and the first telescopic mechanism fixing seat, and a second telescopic mechanism is connected between each second iron core and the second telescopic mechanism fixing seat; both the first telescopic mechanism and the second telescopic mechanism extend in the second direction.

[0031] With the above settings, the position of the first iron core / second iron core in the second direction can be adjusted in the inner circumferential region of the first induction coil / second induction coil, thereby adjusting the magnetic field or eddy current distribution.

[0032] In the above technical solution: both the first coil fixing frame and the second coil fixing frame are box-shaped structures;

[0033] The first telescopic mechanism fixing seat is a first U-shaped heat insulation cover fixed to the side wall of the first coil fixing frame. The fixed end of the first telescopic mechanism is fixed to the inner wall of the first U-shaped heat insulation cover. The telescopic end of the first telescopic mechanism passes through the side wall of the first coil fixing frame, thereby being fixedly connected to the corresponding first iron core.

[0034] The second telescopic mechanism fixing seat is a second U-shaped heat insulation cover fixed to the side wall of the second coil fixing frame. The fixed end of the second telescopic mechanism is fixed to the inner wall of the second U-shaped heat insulation cover. The telescopic end of the second telescopic mechanism passes through the side wall of the second coil fixing frame, thereby being fixedly connected to the corresponding second iron core.

[0035] Through the above settings, the first U-shaped heat shield / second U-shaped heat shield is used to protect the first telescopic mechanism / second telescopic mechanism, reducing the impact of the overheated working environment on the telescopic mechanism.

[0036] In the above technical solution: the control unit of the induction coil located at the same relative position in each group of induction heating units is the same control unit, and the control unit of the induction coil located at different relative positions in each group of induction heating units is a different control unit, or the control unit of each induction coil in each group of induction heating units is set independently.

[0037] The present invention also provides an electromagnetic heating control method using the above-mentioned electromagnetic heating device. The electromagnetic heating control method includes a coil current control step and / or a position adjustment step.

[0038] The coil current control step includes setting the induction heating unit to a first current adjustment mode or a second current adjustment mode.

[0039] The first current adjustment mode is to adjust the current direction in each first induction coil and each second induction coil in the induction heating unit so that the magnetic pole positions formed by the first induction coil and the second induction coil set in the first direction are the same in the first direction.

[0040] The second current adjustment mode is as follows: the current direction in each first induction coil and each second induction coil in the induction heating unit is adjusted so that the magnetic pole positions formed by two adjacent first induction coils in the first direction are opposite, the magnetic pole positions formed by two adjacent second induction coils in the first direction are opposite, and the magnetic pole positions formed by the corresponding first induction coils and second induction coils in the first direction are opposite.

[0041] The position adjustment step includes setting the induction heating unit to a first position adjustment mode or a second position adjustment mode;

[0042] The first position adjustment mode is: adjusting the position of each induction coil in the second direction so that the center of each induction coil in the second direction is located on the longitudinal axis of the slab;

[0043] The second position adjustment mode is: adjusting the position of each induction coil in the second direction, so that the projection of the fourth connecting segment corresponding to each induction coil on the coil plane is located in the projection area of ​​the slab on the coil plane, and satisfying one of the first condition, the second condition, and the third condition.

[0044] The first condition is that the projection of the third connecting segment corresponding to each induction coil on the coil plane coincides with or is tangent to at least one boundary of the projection area of ​​the slab on the coil plane; the second condition is that the projection of the third connecting segment corresponding to each induction coil on the coil plane is located outside the projection area of ​​the slab on the coil plane, and the distance between the projection of the third connecting segment on the coil plane and the projection area of ​​the slab is not greater than a first preset distance; the third condition is that the projection of the third connecting segment (100C) corresponding to each induction coil on the coil plane is located within the projection area of ​​the slab on the coil plane, and the distance between the projection of the third connecting segment on the coil plane and the projection area of ​​the slab is not greater than the first preset distance.

[0045] When the electromagnetic heating control method includes a position adjustment step:

[0046] The projection of each induction coil onto the coil plane is composed of a first connecting segment, a second connecting segment, a third connecting segment, and a fourth connecting segment; the first connecting segment and the second connecting segment are arranged opposite to each other in the slab running direction; the third connecting segment and the fourth connecting segment are arranged opposite to each other in a second direction; one end of the first connecting segment and one end of the second connecting segment are connected to each other through the third connecting segment, and the other ends of the first connecting segment and the second connecting segment are connected to each other through the fourth connecting segment; the third connecting segment is a bulging segment, and the fourth connecting segment is a straight segment; the shape formed by the bulging segment protrudes from the connection point of the bulging segment and the first connecting segment in a direction away from the second connecting segment, and from the connection point of the bulging segment and the second connecting segment in a direction away from the first connecting segment, and in the second direction protrudes towards the side away from the area between the third connecting segment and the fourth connecting segment.

[0047] In this application, through the above-described configuration, the current direction of the induction coil can be adjusted using the coil current control step. This allows most of the magnetic field lines to pass through the first direction from the two first induction coils to the corresponding two second induction coils, or to pass through the second direction from one induction coil to its adjacent induction coil. When needed, the first position adjustment mode can be used to center each coil in the second direction, or the second position adjustment mode can be used to disperse the eddy currents on the side of the slab, reducing the risk of overheating caused by the easy concentration of eddy currents on the side of the slab.

[0048] In the above technical solution: the coil current control step further includes: for a group of induction heating units, determining whether D3 < D2 or D3 ≤ D2 is true;

[0049] If it is determined that D3 < D2 or D3 ≤ D2, then the induction heating unit is set to the first current adjustment mode;

[0050] If it is determined that D3≥D2 or D3>D2, then the induction heating unit is set to the second current adjustment mode;

[0051] Where D3 is the distance between the bottom of the first induction coil and the top of the second induction coil, and D2 is the distance between two adjacent first induction coils.

[0052] With the above settings, when D3 < D2 or D3 ≤ D2, that is, when the distance between the first and second induction coils in the first direction is less than the distance between the two induction coils in the second direction, the first current adjustment mode is adopted, so that most of the magnetic field lines pass through the shorter (or equal) first direction, avoiding the problems of large losses and low heating efficiency caused by the magnetic field having too long a path in the air. Similarly, when D3 ≥ D2 or D3 > D2, the second current adjustment mode is adopted, so that most of the magnetic field lines pass through the shorter (or equal) second direction.

[0053] In the above technical solution: each set of induction heating unit mounting base is also equipped with a U-shaped magnetic field shielding structure; in the second direction, the openings of the two U-shaped magnetic field shielding structures are opposite to each other and both face the slab located in the slab channel, and are adapted to the size of the slab;

[0054] The electromagnetic heating control method further includes:

[0055] When the induction heating unit is in the first current adjustment mode, the position of the U-shaped magnetic field shielding structure in the second direction is adjusted so that the distance between the inner wall of the opening of the U-shaped magnetic field shielding structure and the side of the slab is the second preset distance.

[0056] When the first current adjustment mode is used, the side of the slab is prone to overheating. The above settings protect the side of the slab with a U-shaped magnetic field shielding structure, reducing the overheating effect caused by eddy current accumulation on the side of the slab.

[0057] In the above technical solution: the position adjustment step further includes: for a group of induction heating units, determining whether L1 < L2 or L1 ≤ L2 is true;

[0058] If it is determined that L1 < L2 or L1 ≤ L2, the induction heating unit is set to the first position adjustment mode, and the position of the U-shaped magnetic field shielding structure in the second direction is adjusted so that the distance between the inner wall of the opening of the U-shaped magnetic field shielding structure and the side of the corresponding slab is the second preset distance.

[0059] If it is determined that L1≥L2 or L1>L2, then the induction heating unit is set to the second position adjustment mode;

[0060] Wherein, L1 is the dimension of the slab in the second direction, and the projected dimensions of the first induction coil and the second induction coil in the second direction are both L2.

[0061] With the above settings, when L1 < L2 or L1 ≤ L2, i.e., when the coil completely or basically covers the slab, to reduce the problem of overheating on the side of the slab, the coil and iron core are centered in the second direction, and a U-shaped magnetic field shielding structure is used to shield the magnetic field on the side of the slab, reducing the impact of overheating. When L1 ≥ L2 or L1 > L2, the third connecting section (i.e., the bulging section) is placed close to the side of the slab, while the second connecting section is placed far away from the side of the slab and located within the slab's projection area. This disperses the eddy currents on the side of the slab, reducing the risk of overheating caused by the easy concentration of eddy currents on the side of the slab.

[0062] In the above technical solution: the first induction coil is wound around the outside of the corresponding first iron core, and the second induction coil is wound around the outside of the corresponding second iron core;

[0063] The first position adjustment mode further includes: adjusting the position of each iron core in the second direction so that the center of each iron core in the second direction and the center of each induction coil in the second direction are located on the longitudinal axis of the slab.

[0064] By setting the iron core and coil in the center, the magnetic lines of force are concentrated on the longitudinal axis of the slab (i.e., the center of the slab in the second direction) through the iron core, thereby minimizing the impact of edge overheating.

[0065] In the above technical solution: the first induction coil is wound around the outside of the corresponding first iron core, and the second induction coil is wound around the outside of the corresponding second iron core;

[0066] The second position adjustment mode also includes: adjusting the position of each iron core in the second direction so that the distance between each iron core and the corresponding fourth connecting segment is minimized.

[0067] By setting it up as described above, the iron core can be kept away from the edge (side) of the slab, reducing the overheating effect caused by eddy currents accumulating at the edge of the slab.

[0068] In the above technical solution, the position adjustment step is executed before the coil current control step.

[0069] By setting it up as described above, the position of the components in the induction heating unit can be adjusted in advance to avoid safety hazards caused by moving the coil position when the power is on.

[0070] In the above technical solution, the electromagnetic heating control method further includes:

[0071] When it is detected that the distance between the front end of the slab and the slab channel entrance in the slab running direction is less than or less than or equal to the first preset distance, the position of the first coil fixing frame for accommodating the first induction coil and the position of the second coil fixing frame for accommodating the second induction coil in the first direction of the induction heating unit are adjusted so that when the slab enters the slab channel, there is a gap between the end of the first coil fixing frame near the slab and the slab, and there is a gap between the end of the second coil fixing frame near the slab and the slab.

[0072] When the slab is detected to have entered the slab channel, the positions of the first coil fixing frame and the second coil fixing frame in the first direction are adjusted so that the distance between the first coil fixing frame and the second coil fixing frame in the first direction is the second preset distance.

[0073] With the above settings, the position of the coil fixing frame is adjusted in the first direction before the slab enters the slab channel, thereby preventing the tilted slab from colliding with the electromagnetic heating device and damaging it.

[0074] In the above technical solution, the coil current control step further includes:

[0075] Before the slab enters the slab channel, determine whether T2-T1≥Tr is true;

[0076] If the judgment result is yes, then for the K1 group of induction heating units starting from the last end of the slab running direction, the induction heating unit is set to the first current adjustment mode.

[0077] Where T2 is the temperature at the center of the slab in the second direction, T1 is the temperature at the edge of the slab, Tr is the preset temperature, and K1 is the preset value.

[0078] With the above settings, when the edge temperature is too low, the K1 group of induction heating units can be adjusted to the first current adjustment mode, thereby using transverse magnetic heating to supplement the heat of the edge, so as to increase the edge temperature and avoid cracks caused by the edge temperature being too low.

[0079] Compared with the prior art, the beneficial effects of this invention are:

[0080] (1) The same induction heating system can realize both horizontal magnetic heating mode and vertical magnetic heating mode, which improves the utilization rate of the equipment and greatly reduces the amount of equipment maintenance.

[0081] (2) It solves the technical problem of overheating of the side (i.e. edge) of the slab, and avoids material waste caused by cutting off the overheated slab strip.

[0082] This invention utilizes an electromagnetic heating device and its control method, which can achieve efficient, rapid and continuous heating of slabs to obtain high-performance strips, and can also be flexibly applied to online induction heating of slabs of different specifications, thereby improving equipment utilization, saving production costs, improving product quality and market competitiveness, and has broad application prospects. Attached Figure Description

[0083] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0084] Figure 1 This is a schematic diagram of the overall structure of the electromagnetic heating device according to an embodiment of the present invention (the slab is located in the slab channel).

[0085] Figure 2 for Figure 1 A schematic diagram of the structure of a group of induction heating units;

[0086] Figure 3-1 for Figure 2 A schematic diagram of the structure of two first induction coils / two second induction coils, a first iron core / a second iron core, and a first telescopic mechanism / a second telescopic mechanism in one embodiment;

[0087] Figure 3-2 for Figure 2 A schematic diagram of the structure of two first induction coils / two second induction coils, a first iron core / a second iron core, and a first telescopic mechanism / a second telescopic mechanism in another embodiment of the invention;

[0088] Figure 4-1 for Figure 3-1 A cross-sectional view of the two first induction coils and the two second induction coils located within the first coil fixing frame and the second coil fixing frame;

[0089] Figure 4-2 for Figure 3-1 A schematic diagram of the eddy current distribution generated by an induction coil structure is shown.

[0090] Figure 4-3 This is a schematic diagram of the eddy current distribution generated by an induction coil in the prior art;

[0091] Figure 5 for Figure 2 Schematic diagram of the upper and middle sensors;

[0092] Figure 6 for Figure 5 A schematic diagram of the structure after removing the lifting plate, the third telescopic mechanism, and the transverse support;

[0093] Figure 7 for Figure 2 Schematic diagram of the middle and lower sensors;

[0094] Figure 8 for Figure 1 A schematic diagram of the U-shaped magnetic field shielding structure;

[0095] Figure 9 for Figure 2 Schematic diagram of the middle mounting base;

[0096] Figure 10 This is a flowchart illustrating the process of Embodiment 2 of the present invention;

[0097] Figure 11-1 , Figure 11-2 These refer to the current direction and magnetic field direction of a transverse magnetic circuit heating mode according to Embodiment 2 of the present invention;

[0098] Figure 11-3 The current direction is for another transverse magnetic circuit heating mode in Embodiment 2 of the present invention;

[0099] Figure 12-1 , Figure 12-2 These refer to the current direction and magnetic field line direction of the longitudinal magnetic circuit heating mode in Embodiment 2 of the present invention, respectively.

[0100] Figure 13 This is a schematic diagram showing the relative position of the first induction coil and the slab when preventing overheating of the slab edge in Embodiment 2 of the present invention.

[0101] Figure 14 This is a schematic diagram showing the relative position of the first induction coil and the slab when supplementing the edge temperature in Embodiment 2 of the present invention;

[0102] Figure 15 This is a schematic diagram of the edge temperature and middle temperature of the slab in Embodiment 3 of the present invention;

[0103] Figure 16 This is a schematic diagram showing the relative positions of the two first induction coils, the two second induction coils, and the slab in Embodiment 4 of the present invention;

[0104] Figure 17 This is a schematic diagram of the projected shape of the induction coil in Embodiment 5 of the present invention;

[0105] Figure 18-1 , Figure 18-2 These are schematic diagrams of the projected shape of the induction coil and the corresponding eddy current distribution of Embodiment 6 of the present invention, respectively.

[0106] Figure 19-1 , Figure 19-2 These are schematic diagrams of the projected shape of the induction coil in the prior art, which serves as a comparative example of Example 6, and corresponding schematic diagrams of the eddy current distribution.

[0107] Figure 20 This is a schematic diagram of the projected shape of the induction coil in Embodiment 7 of the present invention.

[0108] In the above attached figures:

[0109] 1-Induction heating unit; 2-Slab;

[0110] 11-Mounting base; 12-Upper sensor; 13-U-shaped magnetic field shielding structure; 14-Lower sensor; 15-Rail; 161-First guide through hole; 162-Second guide through hole; 17-Screw;

[0111] 1200 - First coil fixing frame; 1200A - Second coil fixing frame; 1201 - First induction coil; 1201A - Second induction coil; 12010 - Coil lead wire; 1202 - First iron core; 1202A - Second iron core; 1203 - Lifting plate; 1204 - Lifting pile; 1205 - First telescopic mechanism; 1205A - Second telescopic mechanism; 1206 - Third telescopic mechanism; 1207 - First telescopic mechanism fixing seat; 1208 - First bolt; 1209 - First washer; 1210 - Lateral support; 1211 - Slide groove; 1213 - Guide column; 1214 - Second washer; 1215 - Second bolt; 1216 - Third bolt; 1217 - Fixing pile; 1205A - Second telescopic mechanism; 1207A - Second telescopic mechanism fixing seat;

[0112] 1301 - Vertical sliding support; 1302 - Fifth telescopic mechanism; 1303 - Shielding structure shell;

[0113] 1401-Fixed support; 1402-Fourth telescopic mechanism; 1403-Pulley; 1404-Pulley support; 1405-Pulley bearing; 1406-Pulley connecting rod;

[0114] The symbol "+" indicates that current enters the paper, and the symbol "·" indicates that current flows out of the paper. Detailed Implementation

[0115] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0116] Example 1

[0117] like Figure 1 , Figure 2 This embodiment provides an electromagnetic heating device, defining the channel through which the slab 2 passes as the slab channel, and defining the first direction and the second direction as the height direction and width direction of the slab channel, respectively, or the width direction and height direction of the slab channel, respectively. Figure 1 In the embodiment shown, the first direction is the height of the slab and the second direction is the width of the slab.

[0118] The electromagnetic heating device includes K groups of induction heating units 1, where K ≥ 1. When K ≥ 2, the K groups of induction heating units 1 are spaced apart along the running direction of the slab 2. Each group of induction heating units 1 includes two first induction coils 1201 and two second induction coils 1201A. The two first induction coils 1201 are located above the slab channel and are arranged adjacent to each other in the running direction of the slab 2. The two second induction coils 1201A are located below the slab channel and are arranged adjacent to each other in the running direction of the slab 2. In the first direction, the two first induction coils 1201 and the two second induction coils 1201A of each group of induction heating units are respectively arranged correspondingly; the coil plane of each induction coil is perpendicular to the first direction. In this embodiment, the running direction of the slab is the length direction of the slab channel. A support roller conveyor (not shown in the figure) can be set in the slab channel to transport the slab.

[0119] In each group of induction heating units 1, the control units for induction coils located at the same relative position are the same control unit, while the control units for induction coils located at different relative positions in each group of induction heating units 1 are different control units, or the control units for each induction coil in each group of induction heating units 1 are independently set. For example, in the same group of induction heating units, the two first induction coils are respectively located at the upper left and upper right relative positions, and the two second induction coils are respectively located at the lower left and lower right relative positions. The control unit for induction coils located at the same relative position in each group of induction heating units 1 is the same control unit, meaning that the induction coil located at the upper left, upper right, lower left, and lower right in each group of induction heating units 1 is controlled by the same control unit.

[0120] like Figure 4-1As shown, the projection of each induction coil onto the coil plane is composed of a first connecting segment 100A, a second connecting segment 100B, a third connecting segment 100C, and a fourth connecting segment 100D. The first connecting segment 100A and the second connecting segment 100B are arranged opposite each other in the running direction of the slab 2. The third connecting segment 100C and the fourth connecting segment 100D are arranged opposite each other in a second direction. One end of the first connecting segment 100A and one end of the second connecting segment 100B are connected to each other via the third connecting segment 100C. The other ends of the first connecting segment 100A and the second connecting segment 100B are connected to each other via the fourth connecting segment 100D. The third connecting segment 100C and / or the fourth connecting segment 100D are bulging segments. The shape Z1 formed by the bulging segments protrudes from the connection point between the bulging segment and the first connecting segment 100A in a direction away from the second connecting segment 100B, and from the connection point between the bulging segment and the second connecting segment 100B in a direction away from the first connecting segment 100A, and in a second direction protrudes towards the side of the region Z2 between the third connecting segment 100C and the fourth connecting segment 100D.

[0121] A virtual connection is formed between the connection point of the bulging section and the first connecting section 100A, and between the connection point of the bulging section and the second connecting section 100B. This virtual connection and the bulging section together form the shape Z1 enclosed by the bulging section. The maximum projected size of the shape enclosed by the bulging section on the slab 2 is greater than the maximum distance between the first connecting section 100A and the second connecting section 100B.

[0122] Both the first connecting segment 100A and the second connecting segment 100B are straight line segments parallel to the second direction; the bulging segment is an arc-shaped segment, and the radius of curvature of the arc-shaped segment is greater than half of the distance between the first connecting segment 100A and the second connecting segment 100B. Preferably, the arc-shaped segment is a superior arc segment.

[0123] The third connecting segment 100C is a bulging segment, and the fourth connecting segment 100D is a straight segment.

[0124] like Figure 3-1 As shown, in one embodiment, the third connecting segment 100C of each induction coil in each group of induction heating units 1 is located on the same side in the second direction, and the third connecting segment 100C of each induction coil in each group of induction heating units 1 is located on opposite sides in the second direction from the third connecting segment 100C of each induction coil in the adjacent group of induction heating units 1. For example, Figure 3-1 In the embodiment shown, in this group of induction heating units, the third connecting segment 100C of each induction coil is located to the left of the fourth connecting segment in the second direction, while in this group of induction heating units, the third connecting segment 100C of each induction coil can be located to the right of the fourth connecting segment in the second direction.

[0125] like Figure 3-2As shown, in another embodiment, the third connecting segments 100C corresponding to the two first induction coils 1201 in each group of induction heating units 1 are located on opposite sides in the second direction, while the third connecting segments 100C corresponding to the first induction coil 1201 and the second induction coil 1201A respectively arranged in the first direction in each group of induction heating units 1 are located on the same side in the second direction. For example, Figure 3-1 In the embodiment shown, for each group of induction heating units, a first induction coil 1201 and a third connecting segment 100C of a second induction coil 1201A corresponding to it in the first direction are both located to the left of the fourth connecting segment in the second direction, and another first induction coil 1201 and a third connecting segment 100C of another second induction coil 1201A corresponding to it in the first direction are both located to the right of the fourth connecting segment in the second direction.

[0126] The bulging section formed by the first induction coil 1201 and the bulging section formed by the second induction coil 1201A, which are respectively arranged in the first direction, can be located on the same side in the second direction.

[0127] With the above arrangement, an alternating arrangement is achieved in the running direction (i.e., the third connection section of some induction coils is located on the left and the third connection section of some induction coils is located on the right), so as to complement each other's edge temperature without causing edge overheating.

[0128] like Figure 2 , Figure 5 , Figure 7 , Figure 9 As shown, each induction heating unit 1 includes a mounting base 11, a first coil fixing frame 1200 for accommodating two first induction coils 1201, and a second coil fixing frame 1200A for accommodating two second induction coils 1201A. The mounting base 11 may be a U-shaped frame structure. The first coil fixing frame 1200 is located above the second coil fixing frame 1200A. The first coil fixing frame 1200 and the second coil fixing frame 1200A of each induction heating unit 1 are respectively mounted on the mounting base 11.

[0129] Each set of induction heating unit 1 is also equipped with a first position adjustment mechanism and / or a second position adjustment mechanism on its mounting base 11;

[0130] The first position adjustment mechanism is used to adjust the position of the first coil fixing frame 1200 and / or the second coil fixing frame 1200A in a first direction. The second position adjustment mechanism is used to adjust the position of the first coil fixing frame 1200 and / or the second coil fixing frame 1200A in a second direction.

[0131] In this embodiment, the first position adjustment mechanism includes a third telescopic mechanism 1206 that extends and retracts in the first direction. The fixed end and telescopic end of the third telescopic mechanism 1206 are respectively fixedly connected to the transverse support 1210 and the first coil fixing frame 1200. The transverse support 1210 is mounted on the mounting base 11 and can slide along the first guide through hole 161 in the second direction, thereby adjusting the position of the first coil fixing frame 1200 in the second direction.

[0132] The first position adjustment mechanism may also include a sliding structure that can slide along the second guide hole 162 in the first direction. Figure 7 The fixed support 1401 can slide along the first direction. The fixed support 1401 can be connected to the second coil fixing frame 1200A through the fourth telescopic mechanism 1402 that extends and retracts in the second direction.

[0133] The second position adjustment mechanism may include a transverse support 1210, a track 15 mounted on the inner bottom surface of the mounting base 11, and a pulley 1403 cooperating with the track 15. The pulley 1403 is mounted on the second coil fixing frame 1200A. The second coil fixing frame 1200A slides in the second direction, thereby adjusting the position of the second coil fixing frame 1200A in the second direction. Using the transverse support 1210, the track 15, and the pulley 1403, the relative position of the first coil fixing frame 1200 and the second coil fixing frame 1200A in the second direction can also be adjusted.

[0134] like Figure 2 , Figure 8 As shown, the mounting base 11 is also equipped with a U-shaped magnetic field shielding structure 13; in the second direction, the opening of the U-shaped magnetic field shielding structure 13 faces the slab 2 located in the slab channel and is adapted to the size of the slab 2.

[0135] The U-shaped magnetic field shielding structure 13 includes a shielding structure shell 1303, which is made of conductive material. A flow channel is formed inside the shielding structure shell 1303, and the flow channel contains a liquid cooling medium.

[0136] The shielding structure housing 1303 is connected to the vertical support 1301 via a fifth telescopic mechanism that can extend and retract in the second direction. The vertical support 1301 is mounted on the mounting base 11 and can slide along the first direction. The above structure enables the position adjustment of the shielding structure housing 1303 in the first and second directions.

[0137] like Figure 6 , Figure 7The first coil fixing frame 1200 and the second coil fixing frame 1200A are respectively fixedly connected to the first telescopic mechanism fixing seat 1207 and the second telescopic mechanism fixing seat 1207A; the first induction coil 1201 is wound on the outside of the corresponding first iron core 1202, and the second induction coil 1201A is wound on the outside of the corresponding second iron core 1202A.

[0138] The projected size of the first iron core 1202 in the second direction is smaller than the projected size of the inner circumferential region of the corresponding first induction coil 1201 in the second direction (i.e., the area enclosed by the first induction coil 1201 forms a telescopic space in which the first iron core 1202 can expand and contract in the second direction). The projected size of the second iron core 1202A in the second direction is smaller than the projected size of the inner circumferential region of the corresponding second induction coil 1201A in the second direction (i.e., the area enclosed by the second induction coil 1201A forms a telescopic space in which the first iron core 1202A can expand and contract in the second direction).

[0139] Each first iron core 1202 is connected to a first telescopic mechanism 1205 between itself and the first telescopic mechanism fixing seat 1207, and each second iron core 1202A is connected to a second telescopic mechanism 1205A between itself and the second telescopic mechanism fixing seat 1207A; the first telescopic mechanism 1205 and the second telescopic mechanism 1205A both extend in the second direction.

[0140] Both the first coil fixing frame 1200 and the second coil fixing frame 1200A are box-shaped structures.

[0141] The first telescopic mechanism fixing seat 1207 is a first U-shaped heat insulation cover fixed to the side wall of the first coil fixing frame 1200. The fixed end of the first telescopic mechanism 1205 is fixed to the inner wall of the first U-shaped heat insulation cover. The telescopic end of the first telescopic mechanism 1205 passes through the side wall of the first coil fixing frame 1200, thereby being fixedly connected to the corresponding first iron core 1202.

[0142] The second telescopic mechanism fixing seat 1207A is a second U-shaped heat insulation cover fixed to the side wall of the second coil fixing frame 1200A. The fixed end of the second telescopic mechanism 1205A is fixed to the inner wall of the second U-shaped heat insulation cover. The telescopic end of the second telescopic mechanism 1205A passes through the side wall of the second coil fixing frame 1200A, thereby being fixedly connected to the corresponding second iron core 1202A.

[0143] The following is a more detailed description of Example 1:

[0144] like Figure 2As shown, the electromagnetic heating device consists of a mounting base, an upper inductor, a lower inductor, and eddy current adjustment units (i.e., U-shaped magnetic field shielding structures) located on the left and right sides. The upper inductor, the lower inductor, and the left and right eddy current adjustment units can all be mounted on the mounting base with bolts, and can be moved relative to the slab position using a hydraulic drive system.

[0145] like Figure 5 As shown, the upper sensor comprises a housing (i.e., the first coil fixing frame), a second bolt 1215, a slide groove, a cylinder fixing heat insulation cover (i.e., the first telescopic mechanism fixing seat), a cylinder (i.e., the first telescopic mechanism), and a first bolt 1208. The cylinder is hydraulically driven to move the position of the iron core inside the induction heater, and finally, the second bolt 1215 (i.e., the iron core fixing bolt) is used to fix the position of the iron core. The main function of the cylinder fixing heat insulation cover is to protect the cylinder from damage caused by high-temperature heat radiation. The positions of the iron cores of both the upper and lower sensors within the coils are adjustable.

[0146] like Figure 4-1 , Figure 4-2 , Figure 5 As shown, the internal structure of the sensor mainly consists of a coil, an iron core, and refractory material for fixing the coil. The coil is fixed inside the outer casing, and the refractory material is poured to fix the coil's position. The refractory material wraps the coil, and this refractory-wrapped coil structure is placed inside the sensor casing (i.e., the first and second coil fixing frames), and then the entire structure is placed inside the frame (i.e., the mounting base 11). The iron core moves within the slide groove 1211 under the drive of the hydraulic system via guide posts 1213. The coil inside the sensor adopts a bidirectional large-head structure design, allowing the head coil size to be larger than the tail size.

[0147] Refractory material is provided between the first induction coil 1201 and the inner wall of the first coil fixing frame 1200, and between the second induction coil 1201A and the inner wall of the second coil fixing frame 1200A.

[0148] The large-head structure design disperses the vortices at the edges, solving the problem of vortex concentration at the edges in the large-head section. The large-head structure also takes into account the low edge temperature when entering the induction heater, appropriately increasing the edge temperature as well.

[0149] Each inductor contains a dual-coil structure. The large ends of the two coils can be on the same side or not. This mainly depends on the number of inductors and the requirements for heating temperature uniformity of the slab. If there are fewer heaters and high temperature uniformity is required, the large ends of the two coils are arranged on different sides, resulting in higher temperature uniformity than if they are all on the same side. Furthermore, if multiple inductors (one inductor is one induction heating unit) are used on the production line, each inductor typically has its dual-coil large ends on the same side, but the large ends are alternated between inductors to ensure uniform eddy current distribution.

[0150] like Figure 4-2 This application uses an induction coil with a large-head structure (having a bulging section) and Figure 4-3 A comparison of eddy current distribution in induction coils without the bulging section. By adopting a large-head structure design, the eddy currents at the edge of the slab are dispersed, solving the problem of eddy current concentration at the edge of the slab.

[0151] like Figure 6 , Figure 7 As shown, the upper sensor 12 is equipped with a lifting plate 1203, a transverse support 1210, and a hydraulic cylinder (i.e., the third telescopic mechanism 1206). The upper sensor is suspended on the mounting base 11 by the transverse support 1210, and the distance between the upper sensor and the upper surface of the slab is adjusted by the drive of the hydraulic cylinder.

[0152] The adjustment of the distance between the upper sensor 12 and the lower sensor 14 is mainly to ensure that the upper and lower sensors open when the slab head and tail enter and move away from the sensors, so as to prevent the slab head and tail from tilting and damaging the sensors. In addition, when the tilted head passes through the sensors, the upper and lower sensors close and move close to the slab surface to avoid large losses of the magnetic field generated by the sensors in the air. The close distance between the upper and lower sensors ensures heating efficiency.

[0153] The distance between the two first induction coils 1201 of the upper sensor 12 is equal to the distance between the two second induction coils 1201A of the lower sensor 14.

[0154] In addition, the distance between the lower sensor and the lower surface of the slab does not need to be adjusted; the distance between the upper and lower sensors can be adjusted by opening the upper sensor as wide as possible.

[0155] When the slab 2 has a large size and a high running speed, or when a high heating temperature is required, multiple inductors (i.e., multiple sets of induction heating units) can be installed side by side. Of course, equipment cost will also be considered. Figure 1As shown, in this embodiment 1, four sensors are arranged. The requirements for each sensor (or heater) are based on the temperature and operating speed. The operating speed determines the residence time within the sensor, and the temperature determines the required heating power. The sensor closest to the slab channel inlet can be set to operate at its rated maximum power, and the subsequent sensors output power according to the required heating temperature.

[0156] like Figure 7 As shown, the lower sensor moves within the mounting base 11 using pulleys, which are mounted at the bottom of the lower sensor (i.e., at the bottom of the second coil fixing frame).

[0157] like Figure 8 As shown, the eddy current regulating unit (i.e., the U-shaped magnetic field shielding structure) located on the side consists of a vertical moving support, a hydraulic cylinder (i.e., the fifth telescopic mechanism), and a side conductive plate (i.e., the shielding structure shell). The side conductive plate is composed of hollow copper plates with internal water cooling, primarily used to shield the magnetic field at the edge of the slab when the edge temperature is too high, reducing edge overheating. The U-shaped shielding structure shell has an internal water-cooling structure. The shielding structure shell can be made of a material with high electrical conductivity (such as copper plate) and employs a hollow, water-cooled structure.

[0158] The specific location of the eddy current regulating unit can be determined based on the edge temperature and the middle temperature of the slab. The eddy current regulating unit is used in conjunction with transverse magnetic induction heating and is generally shielded within 50mm of the edge of the slab, that is, at the concave part of the temperature curve (i.e., the position with the lowest temperature in the width direction of the slab).

[0159] By wrapping the sides of the slab with a U-shaped magnetic field shielding structure, the magnetic field at the edges is partially shielded, thus regulating eddy currents and reducing edge overheating. The U-shaped magnetic field shielding structure can be used selectively as needed. Generally, it is only necessary to wrap the sides of the slab with a U-shaped magnetic field shielding structure when the edge temperature is high.

[0160] In this application: 1. The entire production line can be equipped with alternating longitudinal and transverse magnetic configurations. By simply changing the direction of the current within the inductor, the heating mode of the heater can be either longitudinal or transverse magnetic. 2. Each inductor has a dual-coil structure design, which is mainly to facilitate changing the current to achieve longitudinal and transverse magnetic heating modes. 3. The coil has a large-head structure design on one side, which disperses the distribution of eddy currents within the slab and solves the problem of overheating at the edges. 4. An iron core is added in the middle of the coil to concentrate the magnetic field, which is also to solve the problem of overheating at the edges and to concentrate the magnetic lines of force in the middle of the slab.

[0161] Example 2

[0162] This embodiment 2 provides an electromagnetic heating control method using the electromagnetic heating device of embodiment 1. The electromagnetic heating control method includes a coil current control step and / or a position adjustment step.

[0163] The coil current control steps include setting the induction heating unit 1 to a first current adjustment mode or a second current adjustment mode.

[0164] The first current adjustment mode is to adjust the current direction in each first induction coil 1201 and each second induction coil 1201A in the induction heating unit 1 so that the magnetic pole positions formed by the first induction coil (1201) and the second induction coil (1201A) set in the first direction are the same in the first direction.

[0165] In the first current adjustment mode: in the first direction, the magnetic pole positions formed by the two first induction coils 1201 are the same, and the magnetic pole positions formed by the two second induction coils 1201A are the same (e.g., Figure 11-1 Alternatively, in the first direction, the magnetic poles formed by the two first induction coils 1201 are in opposite positions, and the magnetic poles formed by the two second induction coils 1201A are in opposite positions (e.g., Figure 11-3 ).

[0166] When the magnetic poles formed by two induction coils are in the same position, it means that the N poles formed by the two induction coils are either below the S pole or above the S pole; conversely, it means that the N pole formed by one induction coil is below the S pole, and the N pole formed by the other induction coil is above the S pole.

[0167] The second current adjustment mode is as follows: the current direction in each of the first induction coils 1201 and each of the second induction coils 1201A in the induction heating unit 1 is adjusted so that the magnetic pole positions formed by two adjacent first induction coils 1201 in the first direction are opposite, and the magnetic pole positions formed by two adjacent second induction coils 1201A in the first direction are opposite. In the second current adjustment mode, the magnetic pole positions formed by the corresponding first induction coils 1201 and second induction coils 1201A in the first direction are opposite.

[0168] The position adjustment step includes setting the induction heating unit 1 to a first position adjustment mode or a second position adjustment mode.

[0169] The first position adjustment mode is to adjust the position of each induction coil in the second direction so that the center of each induction coil in the second direction is located on the longitudinal axis LCA of the slab (i.e., the center line of the slab).

[0170] The second position adjustment mode is: adjusting the position of each induction coil in the second direction so that the projection of the fourth connecting segment 100D corresponding to each induction coil on the coil plane is located in the projection area of ​​the slab on the coil plane (i.e., making the fourth connecting segment 100D far away from the edge of the slab), and satisfying one of the first condition, the second condition, and the third condition.

[0171] The first condition is that the projection of the third connecting segment 100C corresponding to each induction coil on the coil plane coincides with or is tangent to at least one boundary of the projection area of ​​the slab 2 on the coil plane; the second condition is that the projection of the third connecting segment 100C corresponding to each induction coil on the coil plane is located outside the projection area of ​​the slab on the coil plane, and the distance between the projection of the third connecting segment 100C on the coil plane and the projection area of ​​the slab is not greater than a first preset distance; the third condition is that the projection of the third connecting segment 100C corresponding to each induction coil on the coil plane is located within the projection area of ​​the slab on the coil plane, and the distance between the projection of the third connecting segment 100C on the coil plane and the projection area of ​​the slab is not greater than the first preset distance. When the third connecting segment is arc-shaped, the boundary between the third connecting segment 100C and the slab 2 can be tangent; when the bulge segment is trapezoidal or rectangular, the boundary between the third connecting segment 100C and the slab 2 can coincide. Regarding the second condition, the first preset distance can be set according to actual needs, so that the eddies formed by the third connecting section (100C) can both heat the edge of the slab to a certain extent (avoiding excessive distance) and prevent eddy concentration at the edge. The first preset distance can be 30mm. If the edge temperature is lower than the target temperature, the second condition can be met, i.e., the large-head structure extends beyond the edge of the slab. If the edge temperature is higher than the target temperature, the large-head structure can be located within the projected area of ​​the slab. The third straight segment 100C (i.e., the large-head structure) is usually moved within a range of ±30mm tangent to the edge of the slab.

[0172] When the electromagnetic heating control method includes a position adjustment step:

[0173] The projection of each induction coil onto the coil plane is composed of a first connecting segment 100A, a second connecting segment 100B, a third connecting segment 100C, and a fourth connecting segment 100D; the first connecting segment 100A and the second connecting segment 100B are arranged opposite to each other in the running direction of the slab 2; the third connecting segment 100C and the fourth connecting segment 100D are arranged opposite to each other in the second direction; one end of the first connecting segment 100A and one end of the second connecting segment 100B are connected to each other through the third connecting segment 100C, and the other end of the first connecting segment 100A... The other end of the second connecting segment 100B is connected to each other through the fourth connecting segment 100D; the third connecting segment 100C is a bulging segment, and the fourth connecting segment 100D is a straight segment; the shape formed by the bulging segment protrudes from the connection point of the bulging segment and the first connecting segment 100A in a direction away from the second connecting segment 100B, and from the connection point of the bulging segment and the second connecting segment 100B in a direction away from the first connecting segment 100A, and in a second direction protrudes towards the side away from the area between the third connecting segment 100C and the fourth connecting segment 100D.

[0174] The coil current control step further includes: for a group of induction heating units 1, determining whether D3 < D2 or D3 ≤ D2 is true;

[0175] If it is determined that D3 < D2 or D3 ≤ D2, then the induction heating unit 1 is set to the first current adjustment mode;

[0176] If it is determined that D3≥D2 or D3>D2, then the induction heating unit 1 is set to the second current adjustment mode;

[0177] Where D3 is the distance between the bottom end of the first induction coil 1201 and the top end of the second induction coil 1201A, and D2 is the distance between two adjacent first induction coils 1201. The bottom ends of the two first induction coils 1201 can be at the same height, and the top ends of the two second induction coils 1201A can be at the same height. D2 is the distance between the axes of the two first induction coils (i.e., the axes parallel to the second direction).

[0178] Each set of induction heating unit 1 is also equipped with a U-shaped magnetic field shielding structure 13 on the mounting base 11; in the second direction, the openings of the two U-shaped magnetic field shielding structures 13 (i.e. the openings formed by the shielding structure shell 1303) are opposite to each other and both face the slab 2 located in the slab channel and are adapted to the size of the slab 2.

[0179] The electromagnetic heating control method further includes: when the induction heating unit 1 is in the first current adjustment mode, adjusting the position of the U-shaped magnetic field shielding structure 13 in the second direction, so that the distance between the inner wall of the opening of the U-shaped magnetic field shielding structure 13 and the side of the slab 2 is a second preset distance. The second preset distance can be set according to the requirement of preventing overheating of the edges. The second preset distance can be 50mm. In this application, the edges of the slab and the side of the slab have the same meaning.

[0180] The position adjustment step also includes: for a set of induction heating units 1, determining whether L1 < L2 or L1 ≤ L2 is true;

[0181] If it is determined that L1 < L2 or L1 ≤ L2, then the induction heating unit 1 is set to the first position adjustment mode, and the position of the U-shaped magnetic field shielding structure in the second direction is adjusted so that the distance between the inner wall of the opening of the U-shaped magnetic field shielding structure and the side of the corresponding slab is the second preset distance.

[0182] If it is determined that L1≥L2 or L1>L2, then the induction heating unit 1 is set to the second position adjustment mode.

[0183] L1 is the dimension of the slab 2 in the second direction (i.e., the width of the slab 2). The projected dimensions of the first induction coil 1201 and the second induction coil 1201 in the second direction are both L2 (i.e., the coverage area of ​​the induction coil in the width direction of the slab 2).

[0184] The first induction coil 1201 is wound around the outside of the corresponding first iron core 1202, and the second induction coil 1201A is wound around the outside of the corresponding second iron core 1202A.

[0185] The first position adjustment mode further includes: adjusting the position of each iron core in the second direction so that the center of each iron core in the second direction and the center of each induction coil in the second direction are located on the longitudinal axis LCA of the slab.

[0186] The first induction coil 1201 is wound around the outside of the corresponding first iron core 1202, and the second induction coil 1201A is wound around the outside of the corresponding second iron core 1202A.

[0187] The second position adjustment mode also includes: adjusting the position of each iron core in the second direction so that the distance between each iron core and the corresponding fourth connecting segment 100D is minimized (i.e., adjusting the position of the iron core in the induction coil so that the iron core is located close to the fourth connecting segment 100D and far away from the third connecting segment 100C, i.e., the iron core is located in the induction coil at the position with the smallest distance from the corresponding fourth connecting segment 100D).

[0188] The position adjustment step is performed before the coil current control step.

[0189] The electromagnetic heating control method further includes:

[0190] When the distance between the front end of slab 2 and the slab channel entrance in the running direction of slab 2 is detected to be less than or equal to the first preset distance (i.e., when slab 2 is about to enter the slab channel), the position of the first coil fixing frame 1200 for accommodating the first induction coil 1201 and the position of the second coil fixing frame 1200A for accommodating the second induction coil 1201A in the first direction are adjusted, so that when slab 2 enters the slab channel, there is a gap between the end of the first coil fixing frame 1200 near slab 2 and slab 2, and there is also a gap between the end of the second coil fixing frame 1200A near slab 2 and slab 2. The first preset distance can be set according to actual needs.

[0191] When the blank 2 is detected to enter the blank channel, the positions of the first coil fixing frame 1200 and the second coil fixing frame 1200A in the first direction are adjusted so that the distance between the first coil fixing frame 1200 and the second coil fixing frame 1200A in the first direction is the second preset distance (that is, the distance is adjusted to the normal working distance of the first induction coil and the second induction coil).

[0192] like Figure 10As shown, the electromagnetic heating device of this application includes: a continuous rolling mill, a continuous rolling mill control system, an induction heating system, a signal acquisition system, a temperature measurement system, a data processing system, and a rolled material quality inspection system. The slab passes continuously on the continuous rolling mill. Before entering the induction heating furnace, the signal acquisition system first collects the slab's dimensional parameters, such as width, length, thickness, running speed, and temperature rise requirements, from the continuous rolling mill control system in real time. The collected data is then compared with data from an expert database.

[0193] (i) If there are corresponding process parameters in the expert database, the stirring parameters corresponding to these process parameters in the history of the expert database shall be called first.

[0194] (ii) If there are no identical process parameters in the metallurgical database, the operating parameters of the induction heating system shall be calculated and determined by the function processing system.

[0195] After passing through the induction heater, the quality grade of the slab can be evaluated by the rolling quality inspection system. If the slab is unqualified, an alarm will be triggered to remind and handle it. The quality grade of qualified slabs is determined and transmitted to the expert database in a one-to-one correspondence with the process inputs and heater operating parameters for storage, so as to be called up in the next production stage.

[0196] 1. Steps to determine the direction of current in the sensor

[0197] 1-1. When the distance between the upper and lower inductors, D3, is less than the distance between the two coils, a transverse magnetic circuit (or transverse magnetic field) heating mode is used. Adjust the direction of the current in the lower inductor coil to ensure that the current directions of the upper and lower inductors are the same, such as... Figure 11-1 , Figure 11-2 .

[0198] Considering heating efficiency, when D3 < D2, a transverse magnetic circuit heating is set. Because D3 < D2, the magnetic field is generated as much as possible in the D3 direction to avoid the magnetic field having to travel too far in the air, which would result in large magnetic field loss and low heating efficiency.

[0199] like Figure 11-2 As shown, the magnetic field starts from the N pole and returns to the S pole, forming a magnetic circuit. Figure 11-2 In the middle, most of the magnetic field lines pass through the blank from the N pole of the first induction coil 1201 of the upper inductor and return to the S pole of the second induction coil 1201A of the lower inductor, thus forming Figure 11-2 Magnetic field line structure.

[0200] 1-2. When the distance between the upper and lower inductors, D3, is greater than or equal to the distance between the two coils, a longitudinal magnetic circuit (or longitudinal magnetic field) heating mode is used. Adjust the direction of the current in the lower inductor coil to ensure that the current directions of the upper and lower inductors are opposite, such as... Figure 12-1 , Figure 12-2 As shown.

[0201] When D3 ≥ D2, longitudinal magnetic circuit heating is used. This means the magnetic field lines follow the shortest path, reducing magnetic field loss in the air and improving heating efficiency. Considering the relatively complex positional movement involved in transverse magnetic heating, when D3 = D2, and the efficiency of transverse and longitudinal magnetic heating are the same, longitudinal magnetic heating can be used for simplification when D3 = D2.

[0202] When longitudinal magnetic heating is used, the eddy current adjustment unit can be disabled because the longitudinal magnet is less affected by edge overheating.

[0203] D3 (the distance between the upper and lower sensors) refers to the distance between the bottom of the upper coil and the top of the lower coil.

[0204] Figure 12-2 Since D3≥D2, most of the magnetic field lines return from the N pole of the first induction coil 1201 of the upper sensor to the S pole of another adjacent first induction coil 1201 of the upper sensor, that is, the magnetic field lines do not penetrate the slab (the magnetic field lines choose to take the shortest path).

[0205] In this application, different heating modes are achieved by changing the direction of the current and altering the magnetic field poles of one side of the coil. This allows the magnetic field lines to take the shortest path, improving heating efficiency.

[0206] 2. Steps to determine the location of the sensor

[0207] 2-1. When the plate width L1 ≤ coil length L2, the coil and iron core are centered, and their centers coincide with the center of the plate blank. The eddy current adjustment units on both sides are close to the steel plate to prevent overheating at the edges. Figure 13 As shown.

[0208] Since L1≤L2, the coil fully covers the slab blank, which leads to the problem of overheating at the ends.

[0209] 2-2. When the board width L1 > coil length L2, the coils are installed in a staggered manner, with the large arc side flush with the edge, and the circular side of the coil and the iron core away from the edge. Figure 14 As shown.

[0210] In this application, determining the magnitude relationship between L1 and L2 only affects the coil arrangement and does not affect the selection of transverse and longitudinal magnets. Since the slab has three surfaces for heat dissipation, heat dissipation is faster. When L1 > L2, this arrangement can both utilize the high temperature of the transverse magnet edge to supplement the edge heat and avoid overheating of the edge.

[0211] In this application, the large arc-shaped side (i.e., the large head structure) disperses the vortices mapped onto the slab, reducing overheating at the edge. If the circular side (i.e., the fourth connecting section) is close to the edge, it is easy for the vortices to concentrate at the edge. Therefore, the fourth connecting section is kept away from the edge.

[0212] In the actual implementation of this application, the position of the heater (i.e., the coil mounting frame and iron core) can be moved first, and then the current direction of the heater can be determined by energizing it to heat the slab, thereby avoiding the safety hazards caused by moving it while energized. Depending on the actual working conditions, only the heater can be moved, or only the current flow in the coil can be controlled to select the heating mode.

[0213] Example 3

[0214] like Figure 15 As shown, the difference between this embodiment 3 and embodiment 2 is that before the slab enters the slab channel, it is determined whether T2-T1≥Tr is true; if the determination result is yes, then for the K1 group of induction heating units 1 starting from the last end of the running direction of the slab 2, the induction heating unit 1 is set to the first current adjustment mode.

[0215] Where T2 is the temperature at the center of slab 2 in the second direction, T1 is the temperature at the edge of slab 2, Tr is the preset temperature, and K1 is the preset value. Tr can be 50°C. K1 ≥ 1. For example, K1 can be 1, 2, or 3.

[0216] In this embodiment 3, when the temperature difference between the side of the slab and the middle position of the slab in the second direction is large, for the K1 group of induction heating units 1 (i.e., the K1 group of induction heating units that start at the end of the running direction of the slab 2) (i.e., the K1 group of induction heating units that start near the slab channel entrance), the heating mode is not determined according to the size of D3 and D2, but the first current adjustment mode (i.e., the transverse magnetic heating mode) is directly adopted to increase the temperature of the side of the slab.

[0217] Before the slab enters the slab channel, the surface temperature of the slab's edge and the surface temperature of the slab's middle width are compared. If the surface temperature of the slab's edge is significantly lower than that of the slab's middle width (i.e., there is a large temperature difference between the edge and the middle width), transverse magnetic heating is forcibly applied to raise the edge temperature and prevent cracks caused by excessively low edge temperatures. If there is no significant temperature difference, transverse or longitudinal magnetic heating can still be selected based on the relationship between D1 and D2 as determined in Example 2.

[0218] Example 4

[0219] like Figure 16 As shown, the difference between Embodiment 4 and Embodiment 1 is that the structure of each induction coil does not include a bulging section. That is, the projection of the induction coil on the coil plane is composed of a first connecting segment (straight line segment), a second connecting segment (straight line segment), a third connecting segment (arc segment), and a fourth connecting segment (arc segment).

[0220] Example 5

[0221] like Figure 17As shown, the difference between Embodiment 5 and Embodiment 1 is that the bulging segment is trapezoidal in shape. Specifically, one base of the trapezoid is a virtual line connecting the two connection points M1 and M2, and the other base is larger than the first base and located on the side away from the first base, away from region Z2. In other words, the bulging segment is composed of two sides connected to the first connecting segment 100A and the second connecting segment 100B, respectively, and the second base.

[0222] Example 6

[0223] like Figure 18-1 As shown, the difference between Embodiment 6 and Embodiment 1 is that the bulging section (i.e., the third connecting section 100C) forms a rectangle (i.e., region Z1 in the figure). That is, the dimension of the rectangle formed by the bulging section in the slab running direction is greater than the dimension of region Z2 in the slab running direction. Figure 18-2 To and Figure 18-1 A schematic diagram of the eddy current distribution corresponding to the structure.

[0224] Figure 19-1 , Figure 19-2 These are schematic diagrams showing the projected shape of an induction coil in the prior art, serving as a comparative example of Example 6, and the corresponding eddy current distribution. The distribution of eddy currents on the slab is determined by the amount of contact between the coil and the edge of the slab. Due to the edge effect, the induced eddy currents of the coil on the slab will choose to flow through the edge as much as possible, thus easily accumulating at the edge. Figure 18-2 The red part of the vortex on the right, Figure 19-2 The red portion of the vortex on the right is the area where the vortex is concentrated. Figure 18-1 The width (i.e., the dimension in the running direction) of the Z2 section of the coil structure and Figure 19-2 When the width (i.e., the dimension in the running direction) of the existing coil structure is equal, when Figure 18-1 , Figure 19-1 When both coil structures have the right side flush with the side edge of the slab and the left side located inside the side edge of the slab, it is obvious that the existing technology... Figure 19-1 The eddy currents are more concentrated on the right side of the coil structure (e.g.) Figure 19-2 (The red area along the direction of travel), while in this embodiment Figure 18-1 In the coil structure, the portion of the third connecting section 100C along the running direction has a larger dimension, thus the eddy currents are more dispersed (e.g., Figure 18-2 (The red area along the running direction), therefore, compared with the prior art, the structure of this embodiment is less likely to cause edge overheating.

[0225] Example 7

[0226] like Figure 20As shown, the difference between Embodiment 7 and Embodiment 1 is that the projection of the induction coil consists of two bulging segments and two straight segments. That is, the first connecting segment 100A and the second connecting segment 100B are both straight segments, while the third connecting segment 100C and the fourth connecting segment 100D are both bulging segments. The area enclosed by the third connecting segment 100C is Z1, and the area enclosed by the fourth connecting segment 100D is Z3.

[0227] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0228] The embodiments of the present invention have been described in detail above, but the content described is only a preferred embodiment of the present invention and should not be considered as limiting the scope of the present invention.

Claims

1. An electromagnetic heating device, defining a passage for a slab (2) passing through as a slab passage, defining a first direction as a slab passage height direction, and defining a second direction as a slab passage width direction; characterized in that, the electromagnetic heating device comprises K groups of induction heating units (1), K≥1; when K≥2, the K groups of induction heating units (1) are arranged at intervals along the running direction of the slab (2); each group of induction heating units (1) comprises two first induction coils (1201) and two second induction coils (1201A); the two first induction coils (1201) are arranged adjacent to each other in the running direction of the slab (2) above the slab passage; the two second induction coils (1201A) are arranged adjacent to each other in the running direction of the slab (2) below the slab passage; in the first direction, the two first induction coils (1201) and the two second induction coils (1201A) of each group of induction heating units are arranged correspondingly; the coil plane of each induction coil is perpendicular to the first direction; the projection of each induction coil on the coil plane is composed of a first connecting segment (100A), a second connecting segment (100B), a third connecting segment (100C), and a fourth connecting segment (100D); the first connecting segment (100A) and the second connecting segment (100B) are arranged opposite to each other in the running direction of the slab (2); the third connecting segment (100C) and the fourth connecting segment (100D) are arranged opposite to each other in the second direction; one end of the first connecting segment (100A) and one end of the second connecting segment (100B) are connected to each other through the third connecting segment (100C); the other end of the first connecting segment (100A) and the other end of the second connecting segment (100B) are connected to each other through the fourth connecting segment (100D); the third connecting segment (100C) and / or the fourth connecting segment (100D) is a bulging segment, the shape enclosed by the bulging segment protrudes away from the second connecting segment (100B) at the connection between the bulging segment and the first connecting segment (100A), and protrudes away from the first connecting segment (100A) at the connection between the bulging segment and the second connecting segment (100B), and protrudes away from the side of the region (Z2) between the third connecting segment (100C) and the fourth connecting segment (100D) in the second direction.

2. The electromagnetic heating device according to claim 1, characterized in that: the first connecting segment (100A) and the second connecting segment (100B) are both straight line segments parallel to the second direction; the bulging segment is an arc segment, and the curvature radius of the arc segment is greater than half the distance between the first connecting segment (100A) and the second connecting segment (100B); or the shape enclosed by the bulging segment is a trapezoidal shape; or the shape enclosed by the bulging segment is a rectangular shape.

3. The electromagnetic heating device according to claim 1, characterized in that: the third connecting segment (100C) is a bulging segment, and the fourth connecting segment (100D) is a straight line segment. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The third connection sections (100C) of the respective induction coils of each group of induction heating units (1) are located on the same side in the second direction, and the third connection sections (100C) of the respective induction coils of each group of induction heating units (1) and the third connection sections (100C) of the respective induction coils of the adjacent group of induction heating units (1) are located on different sides in the second direction; or The third connection sections (100C) corresponding to the two first induction coils (1201) in each group of induction heating units (1) are located on different sides in the second direction, and the third connection sections (100C) corresponding to the first induction coils (1201) and the second induction coils (1201A) arranged correspondingly in the first direction are located on the same side in the second direction.

4. The electromagnetic heating device according to claim 1, characterized in that: The control units of the induction coils located at the same relative position in each group of induction heating units (1) are the same control unit, and the control units of the induction coils located at different relative positions in each group of induction heating units (1) are different control units, or the control units of the respective induction coils of each group of induction heating units (1) are independently arranged.

5. The electromagnetic heating device according to any one of claims 1-4, characterized in that: Each group of induction heating units (1) comprises a mounting seat (11), a first coil fixing frame (1200) for accommodating two first induction coils (1201), and a second coil fixing frame (1200A) for accommodating two second induction coils (1201A); The first coil fixing frame (1200) is located above the second coil fixing frame (1200A); The first coil fixing frame (1200) and the second coil fixing frame (1200A) of each group of induction heating units (1) are respectively mounted on the mounting seat (11).

6. The electromagnetic heating device according to claim 5, characterized in that: The mounting seat (11) of each group of induction heating units (1) is further provided with a first position adjusting mechanism and / or a second position adjusting mechanism; The first position adjusting mechanism is used to adjust the position of the first coil fixing frame (1200) and / or the second coil fixing frame (1200A) in the first direction; The second position adjusting mechanism is used to adjust the position of the first coil fixing frame (1200) and / or the second coil fixing frame (1200A) in the second direction.

7. An electromagnetic heating control method using the electromagnetic heating device according to any one of claims 1-6, characterized in that: The electromagnetic heating control method comprises a coil current control step and / or a position adjusting step; The coil current control step comprises setting the induction heating unit (1) to a first current adjustment mode or a second current adjustment mode; The first current adjustment mode is to adjust the current direction in each first induction coil (1201) and each second induction coil (1201A) in the induction heating unit (1), so that the magnetic pole positions formed by the first induction coil (1201) and the second induction coil (1201A) arranged correspondingly in the first direction are the same in the first direction. The second current adjustment mode is to adjust the current direction in each first induction coil (1201) and each second induction coil (1201A) in the induction heating unit (1), so that the magnetic pole positions formed by two adjacent first induction coils (1201) in the first direction are opposite, the magnetic pole positions formed by two adjacent second induction coils (1201A) in the first direction are opposite, and the magnetic pole positions formed by the first induction coil (1201) and the second induction coil (1201A) arranged correspondingly in the first direction are opposite in the first direction; The position adjustment step includes setting the induction heating unit (1) to a first position adjustment mode or a second position adjustment mode; The first position adjustment mode is to adjust the position of each induction coil in the second direction, so that the center of each induction coil in the second direction is located on the slab longitudinal axis (LCA); The second position adjustment mode is to adjust the position of each induction coil in the second direction, so that the projection of the fourth connecting segment (100D) corresponding to each induction coil on the coil plane is located in the projection area of the slab on the coil plane, and so that one of the first condition, the second condition and the third condition is met; The first condition is that the projection of the third connecting segment (100C) corresponding to each induction coil on the coil plane coincides with or is tangent to at least one boundary of the projection area of the slab (2) on the coil plane; the second condition is that the projection of the third connecting segment (100C) corresponding to each induction coil on the coil plane is located outside the projection area of the slab on the coil plane, and the distance between the projection of the third connecting segment (100C) on the coil plane and the slab projection area is not greater than a first preset distance; the third condition is that the projection of the third connecting segment (100C) corresponding to each induction coil on the coil plane is located in the projection area of the slab on the coil plane, and the distance between the projection of the third connecting segment (100C) on the coil plane and the slab projection area is not greater than a first preset distance; When the electromagnetic heating control method includes a position adjustment step: The projection of each induction coil on the coil plane is composed of a first connecting section (100A), a second connecting section (100B), a third connecting section (100C) and a fourth connecting section (100D); the first connecting section (100A) and the second connecting section (100B) are oppositely arranged in the running direction of the slab (2); the third connecting section (100C) and the fourth connecting section (100D) are oppositely arranged in the second direction; one end of the first connecting section (100A) and one end of the second connecting section (100B) are connected to each other through the third connecting section (100C), and the other end of the first connecting section (100A) and the other end of the second connecting section (100B) are connected to each other through the fourth connecting section (100D); the third connecting section (100C) is a bulging section, and the fourth connecting section (100D) is a straight section; the shape surrounded by the bulging section protrudes away from the second connecting section (100B) at the connection between the bulging section and the first connecting section (100A), and protrudes away from the first connecting section (100A) at the connection between the bulging section and the second connecting section (100B), and protrudes away from the side of the region between the third connecting section (100C) and the fourth connecting section (100D) in the second direction.

8. The electromagnetic heating control method of claim 7, wherein: The coil current control step further comprises: for a group of induction heating units (1), judging whether D3 < D2 or D3 ≤ D2 is true; if D3 < D2 or D3 ≤ D2 is true, setting the induction heating unit (1) to the first current adjustment mode; if D3 ≥ D2 or D3 > D2 is true, setting the induction heating unit (1) to the second current adjustment mode; Wherein, D3 is the distance between the bottom end of the first induction coil (1201) and the top end of the second induction coil (1201A), and D2 is the distance between two adjacent first induction coils (1201).

9. The electromagnetic heating control method according to claim 8, characterized in that: Each group of induction heating units (1) comprises a mounting seat (11), a first coil fixing frame (1200) for accommodating two first induction coils (1201), and a second coil fixing frame (1200A) for accommodating two second induction coils (1201A); The first coil fixing frame (1200) is located above the second coil fixing frame (1200A); The first coil fixing frame (1200) and the second coil fixing frame (1200A) of each group of induction heating units (1) are respectively installed on the mounting seat (11); The mounting seat (11) of each group of induction heating units (1) is further provided with a U-shaped magnetic field shielding structure (13); in the second direction, the openings of the two U-shaped magnetic field shielding structures (13) are opposite to each other and both face the slab (2) located in the slab passage and are adapted to the size of the slab (2); The electromagnetic heating control method further comprises: when the induction heating unit (1) is in the first current adjustment mode, adjusting the position of the U-shaped magnetic field shielding structure (13) in the second direction so that the distance between the inner wall surface of the opening of the U-shaped magnetic field shielding structure (13) and the side surface of the slab (2) is the second preset distance.

10. The electromagnetic heating control method according to claim 9, characterized in that: The position adjustment step further comprises: for a group of induction heating units (1), judging whether L1 < L2 or L1 ≤ L2 is true; if L1 < L2 or L1 ≤ L2 is true, setting the induction heating unit (1) to the first position adjustment mode, and adjusting the position of the U-shaped magnetic field shielding structure in the second direction so that the distance between the inner wall surface of the opening of the U-shaped magnetic field shielding structure and the corresponding slab side surface is the second preset distance; if L1 ≥ L2 or L1 > L2 is true, setting the induction heating unit (1) to the second position adjustment mode; Wherein, L1 is the size of the slab (2) in the second direction, and the projection size of the first induction coil (1201) and the second induction coil (1201A) in the second direction is L2.

11. The electromagnetic heating control method according to any one of claims 7-10, characterized in that: The first induction coil (1201) is wound outside the corresponding first core (1202), and the second induction coil (1201A) is wound outside the corresponding second core (1202A); The first position adjustment mode further comprises: adjusting the position of each core in the second direction so that the center of each core in the second direction and the center of each induction coil in the second direction are located on the slab longitudinal axis (LCA).

12. The electromagnetic heating control method according to any one of claims 7-10, characterized in that: The first induction coil (1201) is wound outside the corresponding first core (1202), and the second induction coil (1201A) is wound outside the corresponding second core (1202A); The second position adjustment mode further comprises: adjusting the position of each core in the second direction so that the distance between each core and the corresponding fourth connecting segment (100D) is the smallest.

13. The electromagnetic heating control method according to any one of claims 7-10, characterized in that: The position adjustment step is performed before the coil current control step.

14. The electromagnetic heating control method according to any one of claims 7-10, characterized in that: The electromagnetic heating control method further comprises: When it is detected that the distance between the front end of the slab (2) and the entrance of the slab passage in the running direction of the slab (2) is less than or equal to the first preset distance, the positions of the first coil fixing frame (1200) for accommodating the first induction coil (1201) and the second coil fixing frame (1200A) for accommodating the second induction coil (1201A) in the first direction are adjusted in the group of induction heating units (1), so that when the slab (2) enters the slab passage, the end of the first coil fixing frame (1200) close to the slab (2) has a gap with the slab (2), and the end of the second coil fixing frame (1200A) close to the slab (2) has a gap with the slab (2); When it is detected that the slab (2) enters the slab passage, the positions of the first coil fixing frame (1200) and the second coil fixing frame (1200A) in the first direction are adjusted, so that the distance between the first coil fixing frame (1200) and the second coil fixing frame (1200A) in the first direction is the second preset distance.

15. The electromagnetic heating control method according to any one of claims 7-10, characterized in that: The coil current control step further comprises: Before the slab enters the slab passage, it is determined whether T2-T1≥Tr is true; If the result of the determination is yes, for K1 groups of induction heating units (1) starting from the rear of the running direction of the slab (2), the induction heating units (1) are set to the first current adjustment mode; Wherein, T2 is the center position temperature of the slab (2) in the second direction, T1 is the edge position temperature of the slab (2), Tr is a preset temperature, and K1 is a preset value.

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