Combined induction heating system and control method, slab production line

Abstract

The present invention discloses a combined induction heating system and control method, as well as a slab production line. The system includes N groups of transverse magnetic field heating units, M groups of C-type magnetic induction heating units, a first heating power supply, a second heating power supply, a first temperature detection unit, a second temperature detection unit, and a control device. The control device controls the operating power of the N groups of transverse magnetic field heating units or the heating temperature rise of the center portion of the incoming slab via the first heating power supply based on the temperature collected by the first temperature detection unit and a target temperature; and controls the operating power of the M groups of C-type magnetic induction heating units or the heating temperature rise of the edge portion of the incoming slab via the second heating power supply based on the temperature collected by the second temperature detection unit and the target temperature. The present invention ensures uniform temperature of the entire heated slab and avoids overheating of the slab edge caused by the end effect when the transverse magnetic field heater is used alone for heating.

Description

Technical Field

[0001] The present invention belongs to the technical field of slab heating, and in particular relates to a combined induction heating system and a control method, and a slab production line. Background Art

[0002] Producing high-quality products while reducing production costs is a goal pursued by all industries, and the steel industry is no exception. The rise of mini-process steelmaking stems from its ability to reduce production and R&D costs while simultaneously introducing new technologies to produce high-quality, high-performance products. Over the past two decades, mini-process steelmaking technologies such as CSP (Compact Strip Production), ESP (Endless Strip Production), and CEM (Compact Endless Casting and Rolling Mill) for steel strip production have been adopted worldwide.

[0003] Short-process steelmaking technology combines the relatively independent and dispersed processes of smelting, casting, heating, and rolling in the traditional steelmaking process to achieve continuous steel production on a single production line. This integration necessitates the introduction of new technologies that differ from traditional production processes. Compared to traditional heating, electromagnetic induction heating has become an indispensable and irreplaceable technical method in steelmaking due to its advantages: ① Fast heating speed and high production efficiency; ② Less oxidation damage and high steel yield rate; ③ Accurate temperature control area and high temperature control accuracy; ⑤ Utilizing the workpiece's own eddy currents to generate heat, requiring no fuel or pollution; and ⑥ Compact system and small footprint.

[0004] Slab heating is generally performed using two induction heating magnetic fields: a longitudinal magnetic field (helical coil structure) and a transverse magnetic field (flat coil structure). When heating thin slabs with a longitudinal magnetic field, conventional medium-frequency power supplies are used. This results in extremely low heating efficiency due to the mutual cancellation of induced currents, while the use of high-frequency power supplies significantly increases costs. Furthermore, deformation of the slab during production, such as warping and warping, can easily damage the induction heater coils. This high maintenance frequency significantly impacts continuous production, resulting in high labor intensity and high production costs.

[0005] During transverse magnetic field heating, the induction heaters are distributed above and below the heated slab, and the opening and closing degree of the slab channel can be adjusted, avoiding the risk of the slab hitting the equipment. However, during transverse magnetic field heating, the end effect of the magnetic field causes the induced current on the slab to concentrate at the edges in the width direction of the slab, making the temperature at the edges of the slab several tens of degrees higher than the temperature at the center of the slab, that is, there is a magnetic field end effect; on the other hand, when only transverse magnetic field heating is used, the end effect of transverse magnetic field heating needs to be used to compensate for the edges of the slab where heat dissipates the fastest, but this thermal balance is difficult to control accurately, and when the width of the heated slab changes, it cannot be controlled and adjusted, which cannot meet production needs. In other words, the temperature uniformity of the center of the heated slab and the two ends in the width direction of the slab is an extremely difficult problem to solve.

[0006] To address heating uniformity, patent publication CN 111278182 A discloses an alternating transverse and longitudinal magnetic induction heating system and method. This system employs alternating transverse and longitudinal magnetic field induction heaters to ensure temperature uniformity across the heated slab. However, due to the aforementioned shortcomings of longitudinal magnetic field heating, its application in continuous production still presents unavoidable challenges. Patent publication CN 113923808 A discloses a transverse magnetic induction heating temperature uniformity automatic adjustment system and method. This system employs coils positioned at different locations on the heated slab to eliminate overheating at the ends of the slab's width and ensure uniform heating temperature. This method requires highly precise and complex control. Furthermore, when the coils extend beyond the slab, the magnetic field is significantly lost, significantly reducing heating efficiency, resulting in high energy consumption and increased costs. Summary of the Invention

[0007] The object of the present invention is to provide a combined induction heating system and control method, and a slab production line, so as to solve the temperature uniformity problem existing in transverse magnetic field heating.

[0008] The present invention solves the above technical problems through the following technical solutions: a combined induction heating system comprising:

[0009] N groups of transverse magnetic field heating units are arranged at equal intervals in the direction of slab conveyance and are used to heat the center of the slab, each group of the transverse magnetic field heating units includes a first transverse magnetic field heater and a second transverse magnetic field heater arranged opposite each other in an upper and lower direction, the first transverse magnetic field heater is used to heat the upper surface of the slab, and the second transverse magnetic field heater is used to heat the lower surface of the slab;

[0010] M groups of C-shaped magnetic induction heating units are arranged at equal intervals in the direction of slab conveyance and are used to heat the edge of the slab, each group of the C-shaped magnetic induction heating units is located between two adjacent groups of transverse magnetic field heating units, and includes a first C-shaped magnetic induction heater and a second C-shaped magnetic induction heater arranged opposite to each other on the left and right, the first C-shaped magnetic induction heater is used to heat the edge of one side of the slab, and the second C-shaped magnetic induction heater is used to heat the edge of the other side of the slab;

[0011] A first heating power supply device is used to provide required power to N groups of transverse magnetic field heating units;

[0012] The second heating power supply device is used to provide the required power to the M groups of C-type magnetic induction heating units;

[0013] The first temperature detection unit is used to detect the temperature of the center of the incoming slab;

[0014] The second temperature detection unit is used to detect the temperature of the edge of the incoming slab;

[0015] A control device is used to control the output power of the first heating power supply device according to the temperature collected by the first temperature detection unit and the set target temperature, and then control the operating power of the N groups of transverse magnetic field heating units or the heating temperature rise of the center part of the incoming slab, so that the temperature of the center part of the incoming slab reaches the target temperature; control the output power of the second heating power supply device according to the temperature collected by the second temperature detection unit and the set target temperature, and then control the operating power of the M groups of C-type magnetic induction heating units or the heating temperature rise of the edge part of the incoming slab, so that the temperature of the edge part of the incoming slab reaches the target temperature.

[0016] Furthermore, the gap between the first transverse magnetic field heater and the upper surface of the slab, and the gap between the second transverse magnetic field heater and the lower surface of the slab are both 10 to 50 mm; the projections of the first transverse magnetic field heater and the second transverse magnetic field heater in each group of transverse magnetic field heating units on the slab overlap.

[0017] Furthermore, the positional relationship between each group of C-shaped magnetic induction heating units, the transverse magnetic field heating units between two adjacent groups of C-shaped magnetic induction heating units, and the slab is as follows:

[0018] L+2*B>A

[0019] Wherein, B is the yoke width of the first C-type magnetic induction heater or the second C-type magnetic induction heater, L is the coil length of the corresponding first transverse magnetic field heater or the second transverse magnetic field heater, and A is the slab width.

[0020] Furthermore, there is an overlapping area between the projection of the magnetic yoke of the first C-type magnetic induction heater on the vertical plane and the projection of the corresponding first transverse magnetic field heater and the second transverse magnetic field heater on the vertical plane; there is an overlapping area between the projection of the magnetic yoke of the second C-type magnetic induction heater on the vertical plane and the projection of the corresponding first transverse magnetic field heater and the second transverse magnetic field heater on the vertical plane.

[0021] Furthermore, the first temperature detection unit includes a first temperature sensor, a second temperature sensor and a third temperature sensor, the third temperature sensor is arranged at the rear end of the Nth first transverse magnetic field heater or the second transverse magnetic field heater, the second temperature sensor is arranged at the front end entrance of the first first transverse magnetic field heater or the second transverse magnetic field heater, and the first temperature sensor is arranged at the front end of the second temperature sensor; the spacing between the first temperature sensor and the second temperature sensor in the slab conveying direction, and the spacing between the Nth first transverse magnetic field heater or the second transverse magnetic field heater and the third temperature sensor in the slab moving direction are both equal to the spacing between two adjacent groups of transverse magnetic field heating units;

[0022] The second temperature detection unit includes a fourth temperature sensor, a fifth temperature sensor, and a sixth temperature sensor. The sixth temperature sensor is provided at the rear end of the Mth first C-type magnetic induction heater or the second C-type magnetic induction heater, the fifth temperature sensor is provided at the front end entrance of the first C-type magnetic induction heater or the second C-type magnetic induction heater, and the fourth temperature sensor is provided at the front end of the fifth temperature sensor. The spacing between the fourth temperature sensor and the fifth temperature sensor in the slab conveying direction, and the spacing between the Mth first C-type magnetic induction heater or the second C-type magnetic induction heater and the sixth temperature sensor in the slab moving direction are both equal to the spacing between two adjacent groups of C-type magnetic induction heating units.

[0023] Among them, the first first transverse magnetic field heater or the second transverse magnetic field heater, the first first C-type magnetic induction heater or the second C-type magnetic induction heater all refer to heaters close to the incoming material side, and the front end all refers to the end close to the incoming material side.

[0024] Furthermore, the first temperature detection unit includes N+1 seventh temperature sensors, wherein the N seventh temperature sensors correspond one-to-one to the N groups of transverse magnetic field heating units, and each of the seventh temperature sensors is respectively arranged at the front entrance of the corresponding first transverse magnetic field heater or second transverse magnetic field heater, and the N+1th seventh temperature sensor is arranged at the rear end of the Nth first transverse magnetic field heater or second transverse magnetic field heater;

[0025] The second temperature detection unit includes M+1 eighth temperature sensors, wherein the M eighth temperature sensors correspond one-to-one to the M groups of C-type magnetic induction heating units, and each of the eighth temperature sensors is respectively arranged at the front end entrance of the corresponding first C-type magnetic induction heater or the second C-type magnetic induction heater, and the M+1th eighth temperature sensor is arranged at the rear end of the Mth first C-type magnetic induction heater or the second C-type magnetic induction heater.

[0026] Based on the same inventive concept, the present invention further provides a control method for the combined induction heating system as described above, comprising the following steps:

[0027] Acquire the temperatures collected by the first temperature detection unit and the second temperature detection unit;

[0028] controlling the output power of the first heating power supply device based on the temperature collected by the first temperature detection unit and the target temperature, thereby controlling the operating power of the N groups of transverse magnetic field heating units or the heating temperature rise of the center portion of the incoming slab, so that the temperature of the center portion of the incoming slab reaches the target temperature;

[0029] The output power of the second heating power supply device is controlled according to the temperature collected by the second temperature detection unit and the target temperature, thereby controlling the operating power of the M group of C-type magnetic induction heating units or the heating temperature rise of the edge of the incoming slab, so that the temperature of the edge of the incoming slab reaches the target temperature.

[0030] Furthermore, the temperatures collected by the first temperature detection unit include a first temperature collected by the first temperature sensor, a second temperature collected by the second temperature sensor, and a third temperature collected by the third temperature sensor; the temperatures collected by the second temperature detection unit include a fourth temperature collected by the fourth temperature sensor, a fifth temperature collected by the fifth temperature sensor, and a sixth temperature collected by the sixth temperature sensor;

[0031] The heating temperature rise of the first transverse magnetic field heater or the second transverse magnetic field heater in each transverse magnetic field heating unit on the center of the incoming slab is:

[0032]

[0033] Among them, T c T is the temperature rise of the center of the incoming slab by each first transverse magnetic field heater or second transverse magnetic field heater; m is the target temperature; ΔT 12 is the difference between the first temperature and the second temperature; T2 is the second temperature; T ki is the temperature drop compensation between the i-th first transverse magnetic field heater and the i+1-th first transverse magnetic field heater, or the temperature drop compensation between the i-th second transverse magnetic field heater and the i+1-th second transverse magnetic field heater, TkN Compensating for temperature drop between the Nth first transverse magnetic field heater or the second transverse magnetic field heater and the third temperature sensor;

[0034] The heating temperature rise of the edge of the incoming slab by the first C-type magnetic induction heater or the second C-type magnetic induction heater in each group of C-type magnetic induction heating units is:

[0035]

[0036] Among them, T b ΔT is the temperature rise of the edge of the incoming slab by each first C-type magnetic induction heater or second C-type magnetic induction heater; 45 is the difference between the fourth temperature and the fifth temperature; T5 is the fifth temperature; T kj is the temperature drop compensation between the jth first C-type magnetic induction heater and the j+1th first C-type magnetic induction heater, or the temperature drop compensation between the jth second C-type magnetic induction heater and the j+1th second C-type magnetic induction heater, T kM It is a temperature drop compensation between the Mth first C-type magnetic induction heater or the second C-type magnetic induction heater and the sixth temperature sensor.

[0037] Furthermore, the temperature reduction compensation T ki or T kj The specific calculation formula is:

[0038]

[0039]

[0040] Among them, T kx Temperature compensation T ki or T kj , q is the heat flux density, α is the slab cross-sectional width, β is the slab cross-sectional thickness, v is the slab conveying speed, C0 is the slab specific heat capacity, Δm is the slab mass conveyed per unit time, ε is the blackness or emissivity, σ0 is the Stefan-Boltzmann constant, T0 is the slab temperature, T h is the ambient temperature, is the angle factor from heater to slab surface.

[0041] Further, the temperatures collected by the first temperature detection unit include N+1 seventh temperatures collected by N+1 seventh temperature sensors, and the temperatures collected by the second temperature detection unit include M+1 eighth temperatures collected by M+1 eighth temperature sensors;

[0042] The specific control process of the operating power of N groups of transverse magnetic field heating units is as follows:

[0043] When the target temperature Tm With the 1st seventh temperature T 71 When the difference between the first and second transverse magnetic field heaters is greater than the temperature that can be raised by the first transverse magnetic field heater or the second transverse magnetic field heater running at full power, both the first transverse magnetic field heater and the second transverse magnetic field heater run at full power. When the target temperature T m With the 1st seventh temperature T 71 When the difference between the first and second transverse magnetic field heaters is less than or equal to the temperature that can be raised by the first transverse magnetic field heater or the second transverse magnetic field heater when the first transverse magnetic field heater or the second transverse magnetic field heater is fully powered, the first transverse magnetic field heater and the second transverse magnetic field heater are both used to raise the center of the slab from the seventh temperature T 71 Heating to target temperature T m Power required to operate;

[0044] When the target temperature T m and the 2nd seventh temperature T 72 When the difference between the target temperature and the target temperature is greater than the temperature that can be raised by the second first transverse magnetic field heater or the second transverse magnetic field heater running at full power, both the second first transverse magnetic field heater and the second transverse magnetic field heater run at full power. m and the 2nd seventh temperature T 72 When the difference between the second and third transverse magnetic field heaters is less than or equal to the temperature that can be raised by the second first transverse magnetic field heater or the second transverse magnetic field heater when the second first transverse magnetic field heater is fully powered, the second first transverse magnetic field heater and the second transverse magnetic field heater are both powered to raise the center of the slab from the seventh temperature T 72 Heating to target temperature T m Power required to operate;

[0045] Similarly, when the target temperature T m and the seventh temperature T 7i When the difference is greater than the temperature that can be raised by the full power operation of the i-th first transverse magnetic field heater or the second transverse magnetic field heater, the i-th first transverse magnetic field heater and the second transverse magnetic field heater are both operated at full power until the target temperature T m and the seventh temperature T 7i The difference is less than or equal to the temperature that can be raised by the full power operation of the first transverse magnetic field heater or the second transverse magnetic field heater of the i-th device; when the target temperature T m and the seventh temperature T 7i When the difference between the first and second transverse magnetic field heaters is less than or equal to the temperature that can be raised by the full power operation of the i-th first transverse magnetic field heater or the second transverse magnetic field heater, the i-th first transverse magnetic field heater and the second transverse magnetic field heater both raise the center of the slab from the seventh temperature T 7i Heating to target temperature T m Power required to operate;

[0046] The specific control process of the operating power of M groups of C-type magnetic induction heating units is as follows:

[0047] When the target temperature T m With the 1st eighth temperature T 81 When the difference is greater than the temperature that can be raised by the first C-type magnetic induction heater or the second C-type magnetic induction heater running at full power, both the first C-type magnetic induction heater and the second C-type magnetic induction heater run at full power; when the target temperature T m With the 1st eighth temperature T 81 When the difference between the first and second C-type magnetic induction heaters is less than or equal to the temperature that can be raised by the first C-type magnetic induction heater or the second C-type magnetic induction heater when the first C-type magnetic induction heater or the second C-type magnetic induction heater is fully powered, the first C-type magnetic induction heater and the second C-type magnetic induction heater are both powered to raise the edge of the slab from the eighth temperature T 81 Heating to target temperature T m Power required to operate;

[0048] When the target temperature T m and the 2nd eighth temperature T 82 When the difference is greater than the temperature that can be raised by the second first C-type magnetic induction heater or the second C-type magnetic induction heater running at full power, both the second first C-type magnetic induction heater and the second C-type magnetic induction heater run at full power; when the target temperature T m and the 2nd eighth temperature T 82 When the difference between the second and third C-type magnetic induction heaters is less than or equal to the temperature that can be raised by the second first C-type magnetic induction heater or the second C-type magnetic induction heater when the heater is fully powered, the second first C-type magnetic induction heater and the second C-type magnetic induction heater are both used to raise the edge of the slab from the eighth temperature T 82 Heating to target temperature T m Power required to operate;

[0049] Similarly, when the target temperature T m and the eighth temperature T 8i When the difference is greater than the temperature that can be raised by the full power operation of the i-th first C-type magnetic induction heater or the second C-type magnetic induction heater, the i-th first C-type magnetic induction heater and the second C-type magnetic induction heater are both operated at full power until the target temperature T m and the eighth temperature T 8i The difference is less than or equal to the temperature that can be raised by the full power operation of the first C-type magnetic induction heater or the second C-type magnetic induction heater of the i-th unit; when the target temperature T m and the eighth temperature T 8i When the difference between the first and second C-type magnetic induction heaters is less than or equal to the temperature that can be raised by the full power operation of the i-th first C-type magnetic induction heater or the second C-type magnetic induction heater, the i-th first C-type magnetic induction heater and the second C-type magnetic induction heater both raise the edge of the slab from the eighth temperature T8i Heating to target temperature T m Power required to operate.

[0050] Furthermore, when n sets of transverse magnetic field heating units make the temperature of the center of the slab reach the target temperature T m , and when n<N, the (n+1) to (N-1) groups of transverse magnetic field heating units are controlled not to work, and the Nth group of transverse magnetic field heating units is controlled to perform temperature compensation on the center of the slab;

[0051] When the m groups of C-type magnetic induction heating units make the temperature of the edge of the slab reach the target temperature T m , and when m<M, the (m+1)~(M-1) groups of C-type magnetic induction heating units are controlled not to work, and the Mth group of C-type magnetic induction heating units is controlled to perform temperature compensation on the edge of the slab.

[0052] Based on the same inventive concept, the present invention also provides a slab production line, on which a combined induction heating system as described in any one of the above items is provided.

[0053] Beneficial effects

[0054] Compared with the prior art, the advantages of the present invention are:

[0055] The present invention provides a combined induction heating system and control method, and a slab production line, which utilize N groups of transverse magnetic field heating units to heat only the center of the slab, and M groups of C-type magnetic induction heating units to heat only the two sides of the slab in the width direction, and control the operating power of the transverse magnetic field heating unit and the C-type magnetic induction heating unit according to the actual temperature value fed back by the temperature detection unit, to ensure that different positions of the slab have different heating temperature rises (the edge part dissipates heat slightly faster, so the heating temperature rise is slightly higher; the center part dissipates heat slightly slower, so the heating temperature rise is slightly lower), thereby ensuring the uniformity of the overall temperature of the heated slab, and avoiding the overheating temperature of the edge part in the width direction of the slab caused by the end effect when the transverse magnetic field heater is heated alone.

[0056] N groups of transverse magnetic field heating units and M groups of C-type magnetic induction heating units heat the slab in combination, making the heating channel of the slab an open channel, avoiding damage to the equipment caused by slab deformation; the transverse magnetic field heating unit and the C-type magnetic induction heating unit are respectively matched with independent heating power supply devices, and are independently controlled by their own heating power supply devices. Under the control of the control device, the heater in the heating unit can realize the power output corresponding to the actual required temperature rise, ensuring the effective use of electric energy and saving heating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only one embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0058] Figure 1 is a layout diagram of the combined induction heating system in Example 1 of the present invention;

[0059] Figure 2 Schematic diagram of the distribution of N groups of transverse magnetic field heating units and M groups of C-type magnetic induction heating units on the heated slab in Example 1 of the present invention;

[0060] Figure 3 Schematic diagram of the arrangement of the first temperature detection unit in Example 1 of the present invention;

[0061] Figure 4 1 is a side view of the positional relationship between the C-shaped magnetic induction heating unit and the transverse magnetic field heating unit in Example 1 of the present invention;

[0062] Figure 5 This is a schematic diagram of temperature uniformity control in Example 1 of the present invention;

[0063] Figure 6 This is a schematic diagram of the arrangement of the first temperature detection unit in Example 2 of the present invention.

[0064] Among them, 1-slab, 2-transverse magnetic field heating unit, 21-first transverse magnetic field heater, 22-second transverse magnetic field heater, 3-C-type magnetic induction heating unit, 31-first C-type magnetic induction heater, 32-second C-type magnetic induction heater, 4-temperature detection unit, 41-first temperature sensor, 42-second temperature sensor, 43-third temperature sensor, 44-seventh temperature sensor, I-transverse magnetic field heating unit wiring, II-control signal line, III-C-type magnetic induction heating unit wiring. DETAILED DESCRIPTION

[0065] The following is a clear and complete description of the technical solutions of the present invention in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts are within the scope of protection of the present invention.

[0066] The following specific embodiments are used to describe the technical solution of the present application in detail. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0067] Example 1

[0068] like Figures 1 to 3 As shown, a combined induction heating system provided by an embodiment of the present invention includes N groups of transverse magnetic field heating units 2, M groups of C-type magnetic induction heating units 3, a first heating power supply device, a second heating power supply device, a first temperature detection unit, a second temperature detection unit and a control device, the first temperature detection unit and the second temperature detection unit are respectively connected to the input end of the control device, the output end of the control device is connected to the first heating power supply device and the second heating power supply device, the first heating power supply device is connected to the N groups of transverse magnetic field heating units 2, and the second heating power supply device is connected to the M groups of C-type magnetic induction heating units 3.

[0069] N groups of transverse magnetic field heating units 2 are sequentially arranged in the direction of conveyance of the slab 1 and are used to heat the center portion of the slab 1. Each group of transverse magnetic field heating units 2 includes a first transverse magnetic field heater 21 and a second transverse magnetic field heater 22 arranged in a vertically opposed manner. The first transverse magnetic field heater 21 is used to heat the center portion of the upper surface of the slab 1, and the second transverse magnetic field heater 22 is used to heat the center portion of the lower surface of the slab 1. M groups of C-type magnetic induction heating units 3 are sequentially arranged in the direction of conveyance of the slab 1 and are used to heat the edge portions of the slab 1 (i.e., both sides in the width direction of the slab 1). Each group of C-type magnetic induction heating units 3 is located between two adjacent groups of transverse magnetic field heating units 2 and includes a first C-type magnetic induction heater 31 and a second C-type magnetic induction heater 32 arranged in a horizontally opposed manner. The first C-type magnetic induction heater 31 is used to heat the left edge of the slab 1, and the second C-type magnetic induction heater 32 is used to heat the right edge of the slab 1. In this embodiment, M = N-1.

[0070] The first heating power supply device is configured to provide the required power to N groups of transverse magnetic field heating units 2, and can individually control each group of transverse magnetic field heating units 2; the second heating power supply device is configured to provide the required power to M groups of C-type magnetic induction heating units 3, and can individually control each group of C-type magnetic induction heating units 3.

[0071] like Figure 3As shown, the first temperature detection unit includes a first temperature sensor 41, a second temperature sensor 42, and a third temperature sensor 43. The third temperature sensor 43 is located at the rear end of the Nth first transverse magnetic field heater 21 or the second transverse magnetic field heater 22. The second temperature sensor 42 is located at the front end entrance of the first first transverse magnetic field heater 21 or the second transverse magnetic field heater 22. The second temperature sensor 42 is close to the first first transverse magnetic field heater 21 or the second transverse magnetic field heater 22, shortening the distance between the second temperature sensor 42 and the first first transverse magnetic field heater 21 or the second transverse magnetic field heater 22, thereby reducing the temperature drop between the second temperature sensor 42 and the first first transverse magnetic field heater 21 or the second transverse magnetic field heater 22. The first temperature sensor 41 is located at the front end of the second temperature sensor 42. The spacing between the first temperature sensor 41 and the second temperature sensor 42 in the conveying direction of the slab 1, and the spacing between the Nth first transverse magnetic field heater 21 or the second transverse magnetic field heater 22 and the third temperature sensor 43 in the moving direction of the slab 1 are both equal to the spacing between two adjacent groups of transverse magnetic field heating units 2, which is d.

[0072] Since the first transverse magnetic field heater 21 and the second transverse magnetic field heater 22 in each group of transverse magnetic field heating units 2 are symmetrically arranged in the upper and lower parts, it is only necessary to set the first temperature sensor 41, the second temperature sensor 42 and the third temperature sensor 43 at the corresponding positions of the first transverse magnetic field heater 21 or the second transverse magnetic field heater 22. The first transverse magnetic field heater 21 and the second transverse magnetic field heater 22 in each group of transverse magnetic field heating units 2 can be controlled according to the temperatures collected by the first temperature sensor 41, the second temperature sensor 42 and the third temperature sensor 43.

[0073] Similarly, the second temperature detection unit includes a fourth temperature sensor, a fifth temperature sensor and a sixth temperature sensor. The sixth temperature sensor is arranged at the rear end of the Mth first C-type magnetic induction heater 31 or the second C-type magnetic induction heater 32, the fifth temperature sensor is arranged at the front end entrance of the first first C-type magnetic induction heater 31 or the second C-type magnetic induction heater 32, and the fourth temperature sensor is arranged at the front end of the fifth temperature sensor; the distance between the fourth temperature sensor and the fifth temperature sensor in the conveying direction of the slab 1, and the distance between the Mth first C-type magnetic induction heater 31 or the second C-type magnetic induction heater 32 and the sixth temperature sensor in the movement direction of the slab 1 are equal to the distance between the two adjacent groups of C-type magnetic induction heating units 3.

[0074] Since the first C-type magnetic induction heater 31 and the second C-type magnetic induction heater 32 in each group of C-type magnetic induction heating units 3 are arranged symmetrically on the left and right, it is only necessary to set the fourth temperature sensor, the fifth temperature sensor and the sixth temperature sensor at the corresponding positions of the first C-type magnetic induction heater 31 or the second C-type magnetic induction heater 32. The first C-type magnetic induction heater 31 and the second C-type magnetic induction heater 32 in each group of C-type magnetic induction heating units 3 can be controlled according to the temperatures collected by the fourth temperature sensor, the fifth temperature sensor and the sixth temperature sensor.

[0075] In this example, the first transverse magnetic field heater 21 or the second transverse magnetic field heater 22, the first C-shaped magnetic induction heater 31 or the second C-shaped magnetic induction heater 32 all refer to heaters close to the incoming material side, and the front end all refers to the end close to the incoming material side. Figure 3 shown.

[0076] The control device is configured to control the output power of the first heating power supply device according to the temperature collected by the first temperature detection unit and the target temperature, and then control the heating temperature rise of the center part of the incoming slab 1 by the N groups of transverse magnetic field heating units 2, so that after being heated by the N groups of transverse magnetic field heating units 2, the temperature of the center part of the incoming slab 1 reaches the target temperature; control the output power of the second heating power supply device according to the temperature collected by the second temperature detection unit and the target temperature, and then control the heating temperature rise of the edge part of the incoming slab 1 by the M groups of C-type magnetic induction heating units 3, so that after being heated by the M groups of C-type magnetic induction heating units 3, the temperature of the edge part of the incoming slab 1 reaches the target temperature, and the temperature of the center part of the slab 1 is consistent with that of the edge part of the slab 1, thereby realizing the uniformity control of the overall temperature of the slab 1.

[0077] In one embodiment of the present invention, N groups of transverse magnetic field heating units 2 are arranged at equal intervals, and M groups of C-type magnetic induction heating units 3 are arranged at equal intervals. The number of groups of transverse magnetic field heating units 2 and C-type magnetic induction heating units 3, or the spacing between them, depends on the required heating temperature rise of the incoming slab 1 and the length of the slab 1. The spacing between the groups of heating units, or the number of groups of heating units, can also be adjusted based on the heating requirements and the heating capacity of each heater (including the transverse magnetic field heating units 2 and C-type magnetic induction heating units 3).

[0078] In a specific embodiment of the present invention, the gap between the first transverse magnetic field heater 21 and the upper surface of the slab 1, and the gap between the second transverse magnetic field heater 22 and the lower surface of the slab 1 are both 10 to 50 mm; the projections of the first transverse magnetic field heater 21 and the second transverse magnetic field heater 22 in each group of transverse magnetic field heating units 2 on the slab 1 or on the horizontal plane coincide.

[0079] The transverse magnetic induction unit is only used to heat the center part of the slab 1, so the lengths of the first transverse magnetic field heater 21 and the second transverse magnetic field heater 22 are both smaller than the width of the slab 1 to ensure that the two sides or ends of the slab 1 in the width direction are not heated by the transverse magnetic induction unit, that is, there is no end effect when the transverse magnetic induction unit is heated, and overheating will not occur on the two sides or ends of the slab 1 in the width direction.

[0080] In order to achieve heating of the edge portion or both ends of the width direction of the slab 1, the projection of the magnetic yoke of the C-shaped magnetic induction heating unit 3 on the slab 1 needs to cover the edge portion of the slab 1 that is not heated by the transverse magnetic induction unit, such as Figure 4 As shown, the positional relationship between each group of C-shaped magnetic induction heating units 3, the transverse magnetic field heating unit 2 between two adjacent groups of C-shaped magnetic induction heating units 3, and the slab 1 is:

[0081] L+2*B>A (1)

[0082] Among them, B is the yoke width of the first C-type magnetic induction heater 31 or the second C-type magnetic induction heater 32, L is the coil length of the corresponding first transverse magnetic field heater 21 or the second transverse magnetic field heater 22, and A is the width of the slab 1.

[0083] like Figure 4 As shown, the vertical projection of the yoke of the first C-shaped magnetic induction heater 31 overlaps with the vertical projections of the corresponding first and second transverse magnetic field heaters 21 and 22. Similarly, the vertical projection of the yoke of the second C-shaped magnetic induction heater 32 overlaps with the vertical projections of the corresponding first and second transverse magnetic field heaters 21 and 22, ensuring that the entire slab 1 is heated. In this embodiment, the width of the overlapping area is at least 10 mm. The surface on which the incoming slab is located is considered a horizontal surface, while the surface perpendicular to the incoming slab and parallel to its width is considered a vertical surface.

[0084] Based on the same inventive concept, an embodiment of the present invention further provides a control method for the combined induction heating system as described above. Figure 5 As shown, the control method includes the following steps:

[0085] Step 1: The control device receives a first temperature T1 collected by the first temperature sensor, a second temperature T2 collected by the second temperature sensor, and a third temperature T3 collected by the third temperature sensor; receives a fourth temperature T4 collected by the fourth temperature sensor, a fifth temperature T5 collected by the fifth temperature sensor, and a sixth temperature T6 collected by the sixth temperature sensor.

[0086] Step 2: The control device controls the first heating power supply device and N groups of transverse magnetic field heating units

[0087] Let the difference between the first temperature and the second temperature be ΔT 12 =T1-T2, used to calculate the temperature drop when the slab is transferred between adjacent first transverse magnetic field heaters or adjacent second transverse magnetic field heaters. In addition, since the temperature of the slab increases after heating, the temperature difference between the slab and the surrounding environment is larger, and the convection heat transfer is faster. Therefore, when the slab is transferred between transverse magnetic field heating units, in addition to ΔT 12 In addition to the temperature drop, it is also necessary to increase the cooling compensation T due to the accelerated convective heat transfer after heating. ki , the temperature drop compensation between the first group of transverse magnetic field heating units and the second group of transverse magnetic field heating units is T k1 The temperature drop compensation between the second group of transverse magnetic field heating units and the third group of transverse magnetic field heating units is T k2 , ..., the temperature drop compensation between the Nth group of transverse magnetic field heating units and the third temperature sensor is T kN Obviously, T kN >……>T k2 >T k1 However, in the actual heating process, the temperature of the slab does not rise much after being heated by each set of transverse magnetic field heating units. The heating temperature of the slab during continuous casting and rolling is generally around 100°C. In the process of heating the slab by 100°C after the temperature of the slab itself has reached more than 1000°C, it can be approximately considered that T kN =……=T k2 =T k1 , therefore, T kN Can be set and adjusted to T by the control device kN ,……,T k2 、T k1 to ensure that the center of the slab is heated to the target temperature under different ambient temperatures.

[0088] Target temperature T m The difference between the second temperature T2 (T m -T2), N*ΔT 12 、 The sum of the three is the total temperature that needs to be heated by N first transverse magnetic field heaters or N second transverse magnetic field heaters. The temperature that needs to be heated by a single first transverse magnetic field heater or a single second transverse magnetic field heater is:

[0089]

[0090] Among them, T c T is the temperature rise of the center of the incoming slab by each first transverse magnetic field heater or second transverse magnetic field heater; m is the target temperature; ΔT 12 is the difference between the first temperature and the second temperature; T2 is the second temperature; T kiis the temperature drop compensation between the i-th first transverse magnetic field heater and the i+1-th first transverse magnetic field heater, or the temperature drop compensation between the i-th second transverse magnetic field heater and the i+1-th second transverse magnetic field heater, T kN It is a temperature drop compensation between the Nth first transverse magnetic field heater or the second transverse magnetic field heater and the third temperature sensor.

[0091] That is, each of the first transverse magnetic field heater and the second transverse magnetic field heater needs to output energy to increase T c The center of the slab is heated by a power of degrees Celsius to ensure that the center of the slab is heated to the target temperature. The control device controls the operating power of each first transverse magnetic field heater and the second transverse magnetic field heater by controlling the output power of the first heating power supply device, so that the center temperature of the slab heated by each first transverse magnetic field heater or second transverse magnetic field heater increases by T c The second temperature can also be used as the incoming slab temperature.

[0092] Step 3: The control device controls the second heating power supply device and the M groups of C-type magnetic induction heating units

[0093] Let the difference between the fourth temperature and the fifth temperature be ΔT 45 =T4-T5, used to calculate the temperature drop when the slab is transferred between adjacent first C-type magnetic induction heaters or between adjacent second C-type magnetic induction heaters. In addition, since the temperature of the slab increases after heating, the temperature difference between the slab and the surrounding environment is larger, and the convection heat transfer is faster. Therefore, when the slab is transferred between C-type magnetic induction heating units, ΔT is added. 45 In addition to the temperature drop, it is also necessary to increase the cooling compensation T due to the accelerated convective heat transfer after heating. kj , the temperature drop compensation between the first group of C-type magnetic induction heating units and the second group of C-type magnetic induction heating units is T k1 The temperature drop compensation between the second group of C-type magnetic induction heating units and the third group of C-type magnetic induction heating units is T k2 , ..., the temperature drop compensation between the Mth group of C-type magnetic induction heating units and the sixth temperature sensor is T kM Obviously, T kM >……>T k2 >T k1 However, in the actual heating process, the temperature of the slab does not rise much after being heated by each set of C-type magnetic induction heating units. The heating temperature of the slab during continuous casting and rolling is generally around 100°C. In the process of heating the slab by 100°C after the temperature of the slab itself has reached over 1000°C, it can be approximately considered that T kM =……=T k2 =T k1 , therefore, T kM Can be set and adjusted to T by the control device kM,……,T k2 、T k1 to ensure that the edge of the slab is heated to the target temperature under different ambient temperatures.

[0094] Target temperature T m The difference between the fifth temperature T5 (T m -T5)、M*ΔT 45 、 The sum of the three is the total temperature that needs to be heated by M first C-type magnetic induction heaters or N second C-type magnetic induction heaters. The temperature that needs to be heated by a single first C-type magnetic induction heater or a single second C-type magnetic induction heater is:

[0095]

[0096] Among them, T b ΔT is the temperature rise of the edge of the incoming slab by each first C-type magnetic induction heater or second C-type magnetic induction heater; 45 is the difference between the fourth temperature and the fifth temperature; T5 is the fifth temperature; T kj is the temperature drop compensation between the jth first C-type magnetic induction heater and the j+1th first C-type magnetic induction heater, or the temperature drop compensation between the jth second C-type magnetic induction heater and the j+1th second C-type magnetic induction heater, T kM It is a temperature drop compensation between the Mth first C-type magnetic induction heater or the second C-type magnetic induction heater and the sixth temperature sensor.

[0097] That is, each of the first C-type magnetic induction heater and the second C-type magnetic induction heater needs to output energy to increase T b The power of degrees Celsius is used to heat the edge of the slab to ensure that the edge of the slab is heated to the target temperature. The control device controls the operating power of each first C-type magnetic induction heater and the second C-type magnetic induction heater by controlling the output power of the second heating power supply device, so that the edge temperature of the slab heated by each first C-type magnetic induction heater or the second C-type magnetic induction heater is increased by T b .

[0098] Temperature drop compensation T ki or T kj The temperature can be obtained through the basic equation of heat transfer. The temperature reduction is mainly achieved through heat convection and heat radiation. Heat convection is the heat transfer between the fluid (the ambient air in this invention) and the slab surface. The calculation formula is as follows:

[0099] q=η·ΔT (4)

[0100] Where q is the heat flux, η is the convective heat transfer coefficient, and ΔT is the temperature difference between the slab and the surrounding air.

[0101] Thermal radiation cooling refers to the temperature drop caused by the electromagnetic waves radiated by the high-temperature slab to the surrounding environment. The calculation formula is as follows:

[0102]

[0103] The q value in thermal radiation and convection is combined with relevant parameters such as slab size, conveying speed, specific heat capacity, etc., and converted into the corresponding temperature reduction compensation value according to the law of conservation of energy. Specifically:

[0104]

[0105] Among them, T kx Temperature compensation T ki or T kj , q is the heat flux density, α is the width of the slab cross section, β is the thickness of the slab cross section, v is the conveying speed of the slab, C0 is the specific heat capacity of the slab, Δm is the mass of the slab conveyed per unit time (i.e., the production capacity of the slab, kg / s), ε is the blackness or emissivity, σ0 is the Stefan-Boltzmann constant, T0 is the slab temperature, T h is the ambient temperature, is the angle factor from heater to slab surface.

[0106] Example 2

[0107] A combined induction heating system provided in an embodiment of the present invention includes N groups of transverse magnetic field heating units, M groups of C-type magnetic induction heating units, a first heating power supply device, a second heating power supply device, a first temperature detection unit, a second temperature detection unit and a control device, wherein the first temperature detection unit and the second temperature detection unit are respectively connected to the input end of the control device, the output end of the control device is connected to the first heating power supply device and the second heating power supply device, the first heating power supply device is connected to the N groups of transverse magnetic field heating units, and the second heating power supply device is connected to the M groups of C-type magnetic induction heating units.

[0108] N groups of transverse magnetic field heating units are sequentially arranged in the direction of slab conveyance and are used to heat the center of the slab. Each group of transverse magnetic field heating units includes a first transverse magnetic field heater and a second transverse magnetic field heater arranged opposite each other in a vertical direction. The first transverse magnetic field heater is used to heat the center of the upper surface of the slab, and the second transverse magnetic field heater is used to heat the center of the lower surface of the slab. M groups of C-type magnetic induction heating units are sequentially arranged in the direction of slab conveyance and are used to heat the edge portions of the slab (i.e., both sides in the width direction of the slab). Each group of C-type magnetic induction heating units is located between two adjacent groups of transverse magnetic field heating units and includes a first C-type magnetic induction heater and a second C-type magnetic induction heater arranged opposite each other in a horizontal direction. The first C-type magnetic induction heater is used to heat the left edge of the slab, and the second C-type magnetic induction heater is used to heat the right edge of the slab. In this embodiment, M = N-1.

[0109] The first heating power supply device is configured to provide the required power to N groups of transverse magnetic field heating units, and can control each group of transverse magnetic field heating units individually; the second heating power supply device is configured to provide the required power to M groups of C-type magnetic induction heating units, and can control each group of C-type magnetic induction heating units individually.

[0110] like Figure 6 As shown, the first temperature detection unit includes N+1 seventh temperature sensors 44, wherein the N seventh temperature sensors 44 correspond one-to-one to the N groups of transverse magnetic field heating units, and each seventh temperature sensor 44 is respectively arranged at the front end entrance of the corresponding first transverse magnetic field heater or the second transverse magnetic field heater, and the N+1th seventh temperature sensor 44 is arranged at the rear end of the Nth first transverse magnetic field heater or the second transverse magnetic field heater.

[0111] Since the first transverse magnetic field heater and the second transverse magnetic field heater in each group of transverse magnetic field heating units are symmetrically arranged in the upper and lower parts, it is only necessary to set N+1 seventh temperature sensors 44 at the corresponding positions of the first transverse magnetic field heater or the second transverse magnetic field heater. The first transverse magnetic field heater and the second transverse magnetic field heater in each group of transverse magnetic field heating units can be controlled according to the temperatures collected by the N+1 seventh temperature sensors 44.

[0112] Similarly, the second temperature detection unit includes M+1 eighth temperature sensors, wherein the M eighth temperature sensors correspond one-to-one to the M groups of C-type magnetic induction heating units, and each eighth temperature sensor is respectively arranged at the front end entrance of the corresponding first C-type magnetic induction heater or the second C-type magnetic induction heater, and the M+1th eighth temperature sensor is arranged at the rear end of the Mth first C-type magnetic induction heater or the second C-type magnetic induction heater.

[0113] Since the first C-type magnetic induction heater and the second C-type magnetic induction heater in each group of C-type magnetic induction heating units are arranged symmetrically on the left and right, it is only necessary to set M+1 eighth temperature sensors at the corresponding positions of the first C-type magnetic induction heater or the second C-type magnetic induction heater. The first C-type magnetic induction heater and the second C-type magnetic induction heater in each group of C-type magnetic induction heating units can be controlled according to the temperature collected by the M+1 eighth temperature sensors.

[0114] The control device is configured to control the output power of the first heating power supply device according to the temperature collected by the first temperature detection unit and the target temperature, and then control the operating power of the N groups of transverse magnetic field heating units, so that after being heated by the N groups of transverse magnetic field heating units, the temperature of the center part of the incoming slab reaches the target temperature; control the output power of the second heating power supply device according to the temperature collected by the second temperature detection unit and the target temperature, and then control the operating power of the M groups of C-type magnetic induction heating units, so that after being heated by the M groups of C-type magnetic induction heating units, the temperature of the edge part of the incoming slab reaches the target temperature, and the temperature of the center part of the slab is consistent with that of the edge part of the slab, thereby realizing uniformity control of the overall temperature of the slab.

[0115] Based on the same inventive concept, an embodiment of the present invention further provides a control method for the combined induction heating system as described above, the control method comprising the following steps:

[0116] Step 1: The control device receives N+1 seventh temperatures collected by N+1 seventh temperature sensors; and receives M+1 eighth temperatures collected by M+1 eighth temperature sensors.

[0117] Step 2: The control device controls the first heating power supply device and the N groups of transverse magnetic field heating units.

[0118] The specific control process of the operating power of N groups of transverse magnetic field heating units is as follows:

[0119] When the target temperature T m With the 1st seventh temperature T 71 When the difference is greater than the temperature that can be raised by the first transverse magnetic field heater or the second transverse magnetic field heater running at full power, it indicates that even if the first transverse magnetic field heater or the second transverse magnetic field heater runs at full power, the temperature of the center of the slab cannot be raised from the first seventh temperature T 71 To heat to the target temperature, the first transverse magnetic field heater and the second transverse magnetic field heater (ie, the first group of transverse magnetic field heating units) are controlled to operate at full power.

[0120] When the target temperature T m With the 1st seventh temperature T 71 When the difference is less than or equal to the temperature that can be raised by the first transverse magnetic field heater or the second transverse magnetic field heater running at full power, it indicates that the first transverse magnetic field heater or the second transverse magnetic field heater running at full power or less than full power can raise the temperature of the center of the slab from the first seventh temperature T 71 To heat the slab to the target temperature, the first transverse magnetic field heater and the second transverse magnetic field heater are controlled to heat the center of the slab from the seventh temperature T 71 Heating to target temperature T mThe first group of transverse magnetic field heating units can heat the center of the slab to the target temperature, while the second to Nth groups of transverse magnetic field heating units are inoperative. In this case, the first group of transverse magnetic field heating units operates at full power or less than full power (adaptive power).

[0121] When the target temperature T m and the 2nd seventh temperature T 72 When the difference is greater than the temperature that can be raised by the second first transverse magnetic field heater or the second transverse magnetic field heater running at full power, it indicates that even if the second first transverse magnetic field heater or the second transverse magnetic field heater runs at full power, the temperature of the center of the slab cannot be raised from the second seventh temperature T 72 To heat the heater to the target temperature, the first transverse magnetic field heater and the second transverse magnetic field heater are both controlled to operate at full power. In this case, both the first transverse magnetic field heating unit and the second transverse magnetic field heating unit are operated at full power.

[0122] When the target temperature T m and the 2nd seventh temperature T 72 When the difference is less than or equal to the temperature that can be raised by the second first transverse magnetic field heater or the second transverse magnetic field heater running at full power, it indicates that the second first transverse magnetic field heater or the second transverse magnetic field heater running at full power or less than full power can raise the temperature of the center of the slab from the second seventh temperature T 72 To heat the slab to the target temperature, the second first transverse magnetic field heater and the second transverse magnetic field heater are controlled to heat the center of the slab from the seventh temperature T 72 Heating to target temperature T m In this case, the first and second transverse magnetic field heating units can heat the center of the slab to the target temperature, and the third to Nth transverse magnetic field heating units are inoperative. In this case, the first transverse magnetic field heating unit operates at full power, and the second transverse magnetic field heating unit operates at full power or less than full power (adaptive power).

[0123] Similarly, when the target temperature T m and the seventh temperature T 7i When the difference is greater than the temperature that can be raised by the full power operation of the i-th first transverse magnetic field heater or the second transverse magnetic field heater, the i-th first transverse magnetic field heater and the second transverse magnetic field heater are both operated at full power until the target temperature T m and the seventh temperature T 7iThe difference is less than or equal to the temperature that can be raised by the i-th first or second transverse magnetic field heater at full power (i.e., the first i groups of transverse magnetic field heating units can meet the requirement of heating the center of the slab to the target temperature). In this case, the first to i-th groups of transverse magnetic field heating units all operate at full power.

[0124] When the target temperature T m and the seventh temperature T 7i When the difference between the first and second transverse magnetic field heaters is less than or equal to the temperature that can be raised by the full power operation of the i-th first transverse magnetic field heater or the second transverse magnetic field heater, the i-th first transverse magnetic field heater and the second transverse magnetic field heater both raise the center of the slab from the seventh temperature T 7i Heating to target temperature T m In this case, the 1st to ith transverse magnetic field heating units can heat the center of the slab to the target temperature, and the i+1th to Nth transverse magnetic field heating units are inoperative. In this case, the 1st to i-1th transverse magnetic field heating units all operate at full power, and the ith transverse magnetic field heating unit operates at full power or less than full power (adaptive power).

[0125] Step 3: The control device controls the second heating power supply device and the M groups of C-type magnetic induction heating units.

[0126] The specific control process of the operating power of M groups of C-type magnetic induction heating units is as follows:

[0127] When the target temperature T m With the 1st eighth temperature T 81 When the difference is greater than the temperature that can be increased by the first C-type magnetic induction heater or the second C-type magnetic induction heater running at full power, the first C-type magnetic induction heater and the second C-type magnetic induction heater (i.e., the first group of C-type magnetic induction heating units) both run at full power.

[0128] When the target temperature T m With the 1st eighth temperature T 81 When the difference between the first and second C-type magnetic induction heaters is less than or equal to the temperature that can be raised by the first C-type magnetic induction heater or the second C-type magnetic induction heater when the first C-type magnetic induction heater or the second C-type magnetic induction heater is fully powered, the first C-type magnetic induction heater and the second C-type magnetic induction heater are both powered to raise the edge of the slab from the eighth temperature T 81 Heating to target temperature T m In this case, the first group of C-type magnetic induction heating units can heat the edge of the slab to the target temperature, and the second to Nth groups of C-type magnetic induction heating units do not work. In this case, the first group of C-type magnetic induction heating units operates at full power or less than full power (adaptive power).

[0129] When the target temperature Tm and the 2nd eighth temperature T 82 When the difference is greater than the temperature that can be raised by the second first C-type magnetic induction heater or the second C-type magnetic induction heater running at full power, both the second first C-type magnetic induction heater and the second C-type magnetic induction heater are running at full power. In this case, both the first group of C-type magnetic induction heating units and the second group of C-type magnetic induction heating units are running at full power.

[0130] When the target temperature T m and the 2nd eighth temperature T 82 When the difference between the second and third C-type magnetic induction heaters is less than or equal to the temperature that can be raised by the second first C-type magnetic induction heater or the second C-type magnetic induction heater when the heater is fully powered, the second first C-type magnetic induction heater and the second C-type magnetic induction heater are both used to raise the edge of the slab from the eighth temperature T 82 Heating to target temperature T m In this case, the first and second groups of C-type magnetic induction heating units can heat the edge of the slab to the target temperature, and the third to Nth groups of C-type magnetic induction heating units do not work. In this case, the first group of C-type magnetic induction heating units operates at full power, and the second group of C-type magnetic induction heating units operates at full power or less than full power (adaptive power).

[0131] Similarly, when the target temperature T m and the eighth temperature T 8i When the difference is greater than the temperature that can be raised by the full power operation of the i-th first C-type magnetic induction heater or the second C-type magnetic induction heater, the i-th first C-type magnetic induction heater and the second C-type magnetic induction heater are both operated at full power until the target temperature T m and the eighth temperature T 8i The difference is less than or equal to the temperature that can be raised by the i-th first C-type magnetic induction heater or the second C-type magnetic induction heater when operating at full power (i.e., the first i groups of C-type magnetic induction heating units can meet the requirement of heating the edge of the slab to the target temperature). In this case, the first to i-th groups of C-type magnetic induction heating units all operate at full power.

[0132] When the target temperature T m and the eighth temperature T 8i When the difference between the first and second C-type magnetic induction heaters is less than or equal to the temperature that can be raised by the full power operation of the i-th first C-type magnetic induction heater or the second C-type magnetic induction heater, the i-th first C-type magnetic induction heater and the second C-type magnetic induction heater both raise the edge of the slab from the eighth temperature T 8i Heating to target temperature T mIn this case, the 1st to the i-th group of C-type magnetic induction heating units can heat the edge of the slab to the target temperature, and the i+1th to the Nth group of C-type magnetic induction heating units do not work. In this case, the 1st to the i-1th group of C-type magnetic induction heating units all operate at full power, and the i-th group of C-type magnetic induction heating units operates at full power or less than full power (adaptive power).

[0133] When the incoming slab temperature is high, the presence of the first n groups of transverse magnetic field heating units (n < N) and the first m groups of C-type magnetic induction heating units (m < M) can achieve heating of the center and edge of the slab to the target temperature. However, since the slab will inevitably experience a temperature drop when it is transported to the designated location (without heating), the temperature of the center and edge of the slab will be lower than the target temperature, so temperature compensation of the slab is required. In this embodiment, when the n groups of transverse magnetic field heating units make the temperature of the center of the slab reach the target temperature T m , and when n<N, the (n+1)~(N-1) groups of transverse magnetic field heating units are controlled not to work, and the Nth group of transverse magnetic field heating units is controlled to perform temperature compensation on the center of the slab; when the mth group of C-type magnetic induction heating units makes the temperature of the edge of the slab reach the target temperature T m , and when m < M, the (m+1) to (M-1) groups of C-type magnetic induction heating units are controlled to be inoperative, and the Mth group of C-type magnetic induction heating units is controlled to perform temperature compensation on the edge of the slab. That is, the last group of transverse magnetic field heating units and C-type magnetic induction heating units are controlled to perform temperature compensation on the slab, ensuring that the temperature of the slab delivered to the designated location reaches the target temperature.

[0134] In this embodiment, the specific value of temperature compensation can be obtained from the temperature compensation database. The specific construction method of the temperature compensation database is as follows: when the ambient temperature is T h When the temperature drop of the slab from the nth group of transverse magnetic field heating units to the specified position is measured, it is ΔT nN The measured temperature drop of the slab from the mth group of C-type magnetic induction heating units to the designated position is ΔT mM Based on this actual measurement, the temperature drop from different sets of transverse magnetic field heating units and C-shaped magnetic induction heating units to the designated location under different ambient temperatures is obtained and stored in the control device. Based on the different situations, the control device controls the corresponding heating power supply device, causing the last set of transverse magnetic field heating units and C-shaped magnetic induction heating units to output an appropriate power to compensate for the temperature drop of the slab when it is not heated, ensuring that the slab reaches the target temperature again when it is transported to the designated location.

[0135] The above disclosure is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with this technical field can easily think of changes or modifications within the technical scope disclosed in the present invention, and they should all be covered by the scope of protection of the present invention.

Claims

1. A combined induction heating system, characterized in that: The system comprises: N groups of transverse magnetic field heating units are arranged at equal intervals in the direction of slab conveyance and are used to heat the center portion of the slab, each group of the transverse magnetic field heating units includes a first transverse magnetic field heater and a second transverse magnetic field heater arranged in an upper and lower relative manner, the first transverse magnetic field heater is used to heat the upper surface of the slab, and the second transverse magnetic field heater is used to heat the lower surface of the slab, and the projections of the first transverse magnetic field heater and the second transverse magnetic field heater on the slab overlap; M groups of C-type magnetic induction heating units are arranged in sequence and at equal intervals in the direction of slab conveyance and are used to heat the edge of the slab. Each group of C-type magnetic induction heating units is located between two adjacent groups of transverse magnetic field heating units and includes a first C-type magnetic induction heater and a second C-type magnetic induction heater arranged opposite to each other on the left and right. The first C-type magnetic induction heater is used to heat the edge of one side of the slab, and the second C-type magnetic induction heater is used to heat the edge of the other side of the slab. The positional relationship between each group of C-type magnetic induction heating units, the transverse magnetic field heating unit between the two adjacent groups of C-type magnetic induction heating units, and the slabs is as follows: L+2*B>A Wherein, B is the yoke width of the first C-shaped magnetic induction heater or the second C-shaped magnetic induction heater, L is the coil length of the corresponding first transverse magnetic field heater or the second transverse magnetic field heater, and A is the slab width; A first heating power supply device is used to provide required power to N groups of transverse magnetic field heating units; The second heating power supply device is used to provide the required power to the M groups of C-type magnetic induction heating units; The first temperature detection unit is used to detect the temperature of the center of the incoming slab; The second temperature detection unit is used to detect the temperature of the edge of the incoming slab; A control device is used to control the output power of the first heating power supply device according to the temperature collected by the first temperature detection unit and the set target temperature, and then control the operating power of the N groups of transverse magnetic field heating units or the heating temperature rise of the center part of the incoming slab, so that the temperature of the center part of the incoming slab reaches the target temperature; control the output power of the second heating power supply device according to the temperature collected by the second temperature detection unit and the set target temperature, and then control the operating power of the M groups of C-type magnetic induction heating units or the heating temperature rise of the edge part of the incoming slab, so that the temperature of the edge part of the incoming slab reaches the target temperature.

2. The combined induction heating system according to claim 1, characterized in that: The gap between the first transverse magnetic field heater and the upper surface of the slab, and the gap between the second transverse magnetic field heater and the lower surface of the slab are both 10 to 50 mm.

3. The combined induction heating system according to claim 1, characterized in that: There is an overlapping area between the projection of the magnetic yoke of the first C-type magnetic induction heater on the vertical plane and the projection of the corresponding first transverse magnetic field heater and the second transverse magnetic field heater on the vertical plane; there is an overlapping area between the projection of the magnetic yoke of the second C-type magnetic induction heater on the vertical plane and the projection of the corresponding first transverse magnetic field heater and the second transverse magnetic field heater on the vertical plane.

4. The combined induction heating system according to any one of claims 1 to 3, characterized in that: The first temperature detection unit includes a first temperature sensor, a second temperature sensor, and a third temperature sensor. The third temperature sensor is provided at the rear end of the Nth first transverse magnetic field heater or the second transverse magnetic field heater, the second temperature sensor is provided at the front end entrance of the first first transverse magnetic field heater or the second transverse magnetic field heater, and the first temperature sensor is provided at the front end of the second temperature sensor. The spacing between the first temperature sensor and the second temperature sensor in the slab conveying direction, and the spacing between the Nth first transverse magnetic field heater or the second transverse magnetic field heater and the third temperature sensor in the slab moving direction are both equal to the spacing between two adjacent groups of transverse magnetic field heating units. The second temperature detection unit includes a fourth temperature sensor, a fifth temperature sensor, and a sixth temperature sensor. The sixth temperature sensor is provided at the rear end of the Mth first C-type magnetic induction heater or the second C-type magnetic induction heater, the fifth temperature sensor is provided at the front end entrance of the first C-type magnetic induction heater or the second C-type magnetic induction heater, and the fourth temperature sensor is provided at the front end of the fifth temperature sensor. The spacing between the fourth temperature sensor and the fifth temperature sensor in the slab conveying direction, and the spacing between the Mth first C-type magnetic induction heater or the second C-type magnetic induction heater and the sixth temperature sensor in the slab moving direction are both equal to the spacing between two adjacent groups of C-type magnetic induction heating units. Among them, the first first transverse magnetic field heater or the second transverse magnetic field heater, the first first C-type magnetic induction heater or the second C-type magnetic induction heater all refer to heaters close to the incoming material side, and the front end all refers to the end close to the incoming material side.

5. The combined induction heating system according to any one of claims 1 to 3, characterized in that: The first temperature detection unit includes N+1 seventh temperature sensors, wherein the N seventh temperature sensors correspond one-to-one to the N groups of transverse magnetic field heating units, and each of the seventh temperature sensors is respectively disposed at the front entrance of the corresponding first transverse magnetic field heater or second transverse magnetic field heater, and the N+1th seventh temperature sensor is disposed at the rear end of the Nth first transverse magnetic field heater or second transverse magnetic field heater; The second temperature detection unit includes M+1 eighth temperature sensors, wherein the M eighth temperature sensors correspond one-to-one to the M groups of C-type magnetic induction heating units, and each of the eighth temperature sensors is respectively arranged at the front end entrance of the corresponding first C-type magnetic induction heater or the second C-type magnetic induction heater, and the M+1th eighth temperature sensor is arranged at the rear end of the Mth first C-type magnetic induction heater or the second C-type magnetic induction heater.

6. A control method for a combined induction heating system according to any one of claims 1 to 5, characterized in that: The following steps are involved: Acquire the temperature collected by the first temperature detection unit and the second temperature detection unit; controlling the output power of the first heating power supply device based on the temperature collected by the first temperature detection unit and the target temperature, thereby controlling the operating power of the N groups of transverse magnetic field heating units or the heating temperature rise of the center portion of the incoming slab, so that the temperature of the center portion of the incoming slab reaches the target temperature; The output power of the second heating power supply device is controlled according to the temperature collected by the second temperature detection unit and the target temperature, thereby controlling the operating power of the M group of C-type magnetic induction heating units or the heating temperature rise of the edge of the incoming slab, so that the temperature of the edge of the incoming slab reaches the target temperature.

7. The control method of the combined induction heating system according to claim 6, characterized in that: The temperatures collected by the first temperature detection unit include a first temperature collected by the first temperature sensor, a second temperature collected by the second temperature sensor, and a third temperature collected by the third temperature sensor; the temperatures collected by the second temperature detection unit include a fourth temperature collected by the fourth temperature sensor, a fifth temperature collected by the fifth temperature sensor, and a sixth temperature collected by the sixth temperature sensor; The heating temperature rise of the first transverse magnetic field heater or the second transverse magnetic field heater in each transverse magnetic field heating unit on the center of the incoming slab is: Among them, T c T is the temperature rise of the center of the incoming slab by each first transverse magnetic field heater or second transverse magnetic field heater; m is the target temperature; ΔT 12 is the difference between the first temperature and the second temperature; T2 is the second temperature; T ki is the temperature drop compensation between the i-th first transverse magnetic field heater and the i+1-th first transverse magnetic field heater, or the temperature drop compensation between the i-th second transverse magnetic field heater and the i+1-th second transverse magnetic field heater, T kN Compensating for temperature drop between the Nth first transverse magnetic field heater or the second transverse magnetic field heater and the third temperature sensor; The heating temperature rise of the first C-type magnetic induction heater or the second C-type magnetic induction heater in each group of C-type magnetic induction heating units on the edge of the incoming slab is: Among them, T b ΔT is the temperature rise of the edge of the incoming slab by each first C-type magnetic induction heater or second C-type magnetic induction heater; 45 is the difference between the fourth temperature and the fifth temperature; T5 is the fifth temperature; T kj is the temperature drop compensation between the jth first C-type magnetic induction heater and the j+1th first C-type magnetic induction heater, or the temperature drop compensation between the jth second C-type magnetic induction heater and the j+1th second C-type magnetic induction heater, T kM It is a temperature drop compensation between the Mth first C-type magnetic induction heater or the second C-type magnetic induction heater and the sixth temperature sensor.

8. The control method of the combined induction heating system according to claim 7, characterized in that: The temperature reduction compensation T ki or T kj The specific calculation formula is: Among them, T kx Temperature compensation T ki or T kj , q is the heat flux density, α is the slab cross-sectional width, β is the slab cross-sectional thickness, v is the slab conveying speed, C0 is the slab specific heat capacity, Δm is the slab mass conveyed per unit time, ε is the emissivity, σ0 is the Stefan-Boltzmann constant, T0 is the slab temperature, T h is the ambient temperature, is the angle factor from heater to slab surface.

9. The control method of the combined induction heating system according to claim 6, characterized in that: The temperatures collected by the first temperature detection unit include N+1 seventh temperatures collected by N+1 seventh temperature sensors, and the temperatures collected by the second temperature detection unit include M+1 eighth temperatures collected by M+1 eighth temperature sensors; The specific control process of the operating power of N groups of transverse magnetic field heating units is as follows: When the target temperature T m With the 1st seventh temperature T 71 When the difference between the first and second transverse magnetic field heaters is greater than the temperature that can be raised by the first transverse magnetic field heater or the second transverse magnetic field heater running at full power, both the first transverse magnetic field heater and the second transverse magnetic field heater run at full power. When the target temperature T m With the 1st seventh temperature T 71 When the difference between the first and second transverse magnetic field heaters is less than or equal to the temperature that can be raised by the first transverse magnetic field heater or the second transverse magnetic field heater when the first transverse magnetic field heater or the second transverse magnetic field heater is fully powered, the first transverse magnetic field heater and the second transverse magnetic field heater are both used to raise the center of the slab from the seventh temperature T 71 Heating to target temperature T m Power required to operate; When the target temperature T m and the 2nd seventh temperature T 72 When the difference between the target temperature and the target temperature is greater than the temperature that can be raised by the second first transverse magnetic field heater or the second transverse magnetic field heater running at full power, both the second first transverse magnetic field heater and the second transverse magnetic field heater run at full power. m and the 2nd seventh temperature T 72 When the difference between the second and third transverse magnetic field heaters is less than or equal to the temperature that can be raised by the second first transverse magnetic field heater or the second transverse magnetic field heater when the second first transverse magnetic field heater is fully powered, the second first transverse magnetic field heater and the second transverse magnetic field heater are both powered to raise the center of the slab from the seventh temperature T 72 Heating to target temperature T m Power required to operate; Similarly, when the target temperature T m and the seventh temperature T 7i When the difference is greater than the temperature that can be raised by the full power operation of the i-th first transverse magnetic field heater or the second transverse magnetic field heater, the i-th first transverse magnetic field heater and the second transverse magnetic field heater are both operated at full power until the target temperature T m and the seventh temperature T 7i The difference is less than or equal to the temperature that can be raised by the full power operation of the first transverse magnetic field heater or the second transverse magnetic field heater of the i-th device; when the target temperature T m and the seventh temperature T 7i When the difference between the first and second transverse magnetic field heaters is less than or equal to the temperature that can be raised by the full power operation of the i-th first transverse magnetic field heater or the second transverse magnetic field heater, the i-th first transverse magnetic field heater and the second transverse magnetic field heater both raise the center of the slab from the seventh temperature T 7i Heating to target temperature T m Power required to operate; The specific control process of the operating power of M groups of C-type magnetic induction heating units is as follows: When the target temperature T m With the 1st eighth temperature T 81 When the difference is greater than the temperature that can be raised by the first C-type magnetic induction heater or the second C-type magnetic induction heater running at full power, both the first C-type magnetic induction heater and the second C-type magnetic induction heater run at full power; when the target temperature T m With the 1st eighth temperature T 81 When the difference between the first and second C-type magnetic induction heaters is less than or equal to the temperature that can be raised by the first C-type magnetic induction heater or the second C-type magnetic induction heater when the first C-type magnetic induction heater or the second C-type magnetic induction heater is fully powered, the first C-type magnetic induction heater and the second C-type magnetic induction heater are both powered to raise the edge of the slab from the eighth temperature T 81 Heating to target temperature T m Power required to operate; When the target temperature T m and the 2nd eighth temperature T 82 When the difference is greater than the temperature that can be raised by the second first C-type magnetic induction heater or the second C-type magnetic induction heater running at full power, both the second first C-type magnetic induction heater and the second C-type magnetic induction heater run at full power; when the target temperature T m and the 2nd eighth temperature T 82 When the difference between the second and third C-type magnetic induction heaters is less than or equal to the temperature that can be raised by the second first C-type magnetic induction heater or the second C-type magnetic induction heater when the heater is fully powered, the second first C-type magnetic induction heater and the second C-type magnetic induction heater are both used to raise the edge of the slab from the eighth temperature T 82 Heating to target temperature T m Power required to operate; Similarly, when the target temperature T m and the eighth temperature T 8i When the difference is greater than the temperature that can be raised by the full power operation of the i-th first C-type magnetic induction heater or the second C-type magnetic induction heater, the i-th first C-type magnetic induction heater and the second C-type magnetic induction heater are both operated at full power until the target temperature T m and the eighth temperature T 8i The difference is less than or equal to the temperature that can be raised by the full power operation of the first C-type magnetic induction heater or the second C-type magnetic induction heater of the i-th unit; when the target temperature T m and the eighth temperature T 8i When the difference between the first and second C-type magnetic induction heaters is less than or equal to the temperature that can be raised by the full power operation of the i-th first C-type magnetic induction heater or the second C-type magnetic induction heater, the i-th first C-type magnetic induction heater and the second C-type magnetic induction heater both raise the edge of the slab from the eighth temperature T 8i Heating to target temperature T m Power required to operate.

10. The control method of the combined induction heating system according to claim 9, characterized in that: When n groups of transverse magnetic field heating units make the temperature of the center of the slab reach the target temperature T m , and when n<N, the (n+1) to (N-1) groups of transverse magnetic field heating units are controlled not to work, and the Nth group of transverse magnetic field heating units is controlled to perform temperature compensation on the center of the slab; When the m groups of C-type magnetic induction heating units make the temperature of the edge of the slab reach the target temperature T m , and when m<M, the (m+1)~(M-1) groups of C-type magnetic induction heating units are controlled not to work, and the Mth group of C-type magnetic induction heating units is controlled to perform temperature compensation on the edge of the slab.

11. A slab production line, characterized by: A combined induction heating system as claimed in any one of claims 1 to 5 is provided thereon.

Images