Annealing method and device for new energy large-capacity amorphous three-dimensional core

Abstract

The application provides an annealing method and device for a new energy large-capacity amorphous three-dimensional iron core, which comprises the following steps: placing the large-capacity amorphous three-dimensional iron core in a three-dimensional adjustable heating cavity; adjusting the pressure value and oxygen content of the three-dimensional adjustable heating cavity to a set range; increasing the temperature of the three-dimensional adjustable heating cavity to an annealing temperature at a set temperature increasing rate, and then keeping the temperature for a set time; applying a weak alternating magnetic field in the keeping temperature stage to induce the magnetic domains to be orderly arranged along the magnetic path direction; and cooling to room temperature at a set gradient cooling rate after the keeping temperature stage is over, so that the annealing of the large-capacity amorphous three-dimensional iron core is completed. The three key process targets of stress elimination, magnetic domain ordering and thermal stress control in the amorphous three-dimensional iron core are precisely coupled on the time axis, so that the consistency and stability of the magnetic performance are ensured.

Description

Technical Field

[0001] This invention belongs to the field of heat treatment technology for amorphous alloy materials, specifically relating to an annealing method and apparatus for large-capacity amorphous three-dimensional iron cores for new energy. Background Technology

[0002] Amorphous alloys, due to their low hysteresis loss, high permeability, and excellent soft magnetic properties, are widely used in core components such as high-efficiency energy-saving distribution transformers, reactors in new energy power generation systems, and high-frequency transformers. Among them, three-dimensional wound amorphous iron cores, due to their advantages such as symmetrical structure, closed magnetic circuit, and three-phase magnetic flux balance, have become a key component of the new generation of high-efficiency distribution transformers. However, amorphous alloys exhibit internal stress during manufacturing, which severely affects their magnetic properties. Precisely controlled annealing processes are necessary to eliminate stress and induce magnetic domain orientation, thereby obtaining optimal soft magnetic characteristics. Traditional annealing equipment is mostly designed for planar wound iron cores, making it difficult to meet the spatial structure requirements of large-capacity (rated capacity ≥ 2500 kVA) three-dimensional iron cores. Furthermore, existing equipment generally suffers from problems such as uneven temperature field, low atmosphere control precision, and uncontrollable cooling rate, resulting in poor consistency of the magnetic properties of the iron core after annealing, and even localized crystallization failure.

[0003] Therefore, there is an urgent need to develop an annealing equipment and supporting annealing method specifically for large-capacity amorphous three-dimensional iron cores for new energy, so as to achieve uniform heating, precise temperature control, inert atmosphere protection and gradient cooling, and ensure that the overall magnetic properties of the iron core meet the standards and are stable. Summary of the Invention

[0004] The purpose of this invention is to provide an annealing method and apparatus for large-capacity amorphous three-dimensional iron cores for new energy, which solves the problems of uneven annealing temperature, poor atmosphere control, and uncontrollable cooling process in the prior art, and improves the magnetic performance consistency and yield of large-capacity amorphous three-dimensional iron cores.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides an annealing method for large-capacity amorphous three-dimensional iron cores for new energy applications, comprising the following steps: A large-capacity amorphous three-dimensional iron core is placed in a three-dimensional adjustable heating cavity; Adjust the pressure and oxygen content of the three-dimensional adjustable heating chamber to the set range; The temperature of the three-dimensional adjustable heating chamber is raised to the annealing temperature at a set heating rate, and then held at that temperature for a set time. A weak alternating magnetic field is applied during the heat preservation stage to induce the magnetic domains to align in an orderly manner along the magnetic circuit direction; After the heat preservation is completed, the core is cooled to room temperature at a set gradient cooling rate to complete the annealing of the large-capacity amorphous solid iron core.

[0006] Preferably, the pressure value of the three-dimensional adjustable heating cavity is less than or equal to 10 Pa.

[0007] Preferably, the oxygen content of the three-dimensional adjustable heating cavity is less than or equal to 10 ppm.

[0008] Preferably, the temperature of the three-dimensional adjustable heating chamber is raised to the annealing temperature at a set heating rate, and then held at that temperature for a set time. The specific process parameters are: The temperature of the three-dimensional adjustable heating chamber is raised to the annealing temperature at a heating rate of 1–3℃ / min, and then held at that temperature for 1–4 hours.

[0009] Preferably, the frequency of the weak alternating magnetic field is 50–400 Hz and the intensity is 0.5–2 Oe.

[0010] Preferably, the cooling process is carried out at a set gradient cooling rate to room temperature. Specific process parameters are as follows: First, cool to 50°C below the Curie temperature at a rate of 2–5°C / min; Next, it is slowly cooled to 150°C at a rate of 0.5–1°C / min; Finally, allow it to cool naturally to room temperature.

[0011] In a first aspect, the present invention provides an annealing apparatus for large-capacity amorphous three-dimensional iron cores in new energy applications, based on the aforementioned annealing method, comprising a three-dimensional adjustable heating cavity, an inert atmosphere circulation assembly, a magnetic shielding support frame, and a gradient cooling assembly, wherein: The magnetic shielding support frame is placed inside the cavity of the three-dimensional adjustable heating cavity to support the amorphous three-dimensional iron core; The outlet of the inert atmosphere circulation assembly is connected to the inlet of the three-dimensional adjustable heating cavity to provide inert gas to the three-dimensional adjustable heating cavity, thereby adjusting the oxygen content in the three-dimensional adjustable heating cavity. The cold air outlet on the gradient cooling component is connected to the cold air inlet of the three-dimensional adjustable heating cavity to provide cooling gas to the three-dimensional adjustable heating cavity.

[0012] Preferably, the inner cavity of the three-dimensional adjustable heating cavity is divided into a top temperature control zone, a middle temperature control zone and a bottom temperature control zone from top to bottom. Each of the top temperature control zone, the middle temperature control zone and the bottom temperature control zone is provided with an infrared radiation heating unit. The multiple infrared radiation heating units in the inner cavity are arranged in a three-dimensional symmetrical manner around the amorphous three-dimensional iron core. Each temperature control zone is equipped with multiple thermocouples, which are evenly distributed around the amorphous three-dimensional iron core. The infrared radiation heating unit and thermocouple in each temperature control zone are connected to the PID controller.

[0013] Preferably, the annealing device includes an excitation coil mounted on the outer wall of the three-dimensional adjustable heating chamber, and the excitation coil is connected to an AC power supply.

[0014] Preferably, the inert atmosphere circulation assembly includes an air supply unit, a circulating fan, and an exhaust gas purification unit, wherein: The air supply unit is connected to the air inlet on the three-dimensional adjustable heating cavity via a circulating fan; The air outlet on the three-dimensional adjustable heating cavity is connected to the air supply unit via the exhaust gas purification unit.

[0015] Compared with the prior art, the beneficial effects of the present invention are: This invention provides an annealing method for large-capacity amorphous three-dimensional iron cores in new energy applications. Through an ordered and parameterized sequence of operations—pressure and oxygen content adjustment, heating and holding, magnetic field induction, and gradient cooling—the three key process objectives of eliminating internal stress, ordering magnetic domains, and controlling thermal stress in the amorphous three-dimensional iron core are precisely coupled on the time axis, thereby ensuring the consistency and stability of magnetic properties. At the same time, this invention effectively solves the systemic defects of traditional annealing devices, such as uneven temperature field and uncontrollable cooling. Its beneficial effects are directly reflected in the overall performance and process adaptability of the device. Detailed Implementation

[0016] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0017] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0018] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0019] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0020] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0021] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0022] Example 1 This embodiment provides an annealing device for large-capacity amorphous three-dimensional iron cores in new energy applications, comprising a three-dimensional adjustable heating cavity, an inert atmosphere circulation assembly, a magnetic shielding support frame, and a gradient cooling assembly, wherein: The magnetic shielding support frame is placed inside the cavity of the three-dimensional adjustable heating cavity to support the amorphous three-dimensional iron core; The outlet of the inert atmosphere circulation assembly is connected to the inlet of the three-dimensional adjustable heating cavity to provide inert gas to the three-dimensional adjustable heating cavity, thereby adjusting the oxygen content in the three-dimensional adjustable heating cavity. The cold air outlet on the gradient cooling component is connected to the cold air inlet of the three-dimensional adjustable heating cavity to provide cooling gas to the three-dimensional adjustable heating cavity.

[0023] Example 2 Based on Example 1, this example provides an annealing device for a large-capacity amorphous three-dimensional iron core in new energy. The three-dimensional adjustable heating cavity includes an outer shell with an octahedral or cubic structure. The inner cavity of the outer shell is divided into a top temperature control zone, a middle temperature control zone, and a bottom temperature control zone from top to bottom. Each of the top, middle, and bottom temperature control zones is equipped with an infrared radiation heating unit. Multiple infrared radiation heating units in the inner cavity are arranged in a three-dimensional symmetrical manner around the amorphous three-dimensional iron core to form a 360° uniform thermal field around the amorphous three-dimensional iron core.

[0024] Each temperature control zone is equipped with multiple thermocouples, which are evenly distributed around the amorphous three-dimensional iron core to monitor the temperature of the 360° uniform thermal field of the amorphous three-dimensional iron core.

[0025] The infrared radiation heating unit and thermocouple in each temperature control zone are connected to the PID controller.

[0026] The temperature of each zone is precisely controlled independently in a closed loop using a PID controller with a preset process curve, ensuring temperature uniformity within the cavity.

[0027] In this embodiment, the temperature deviation of the large-size three-dimensional iron core is ≤±3℃ throughout by three-dimensional symmetrical heating and multi-zone temperature control.

[0028] Example 3 Based on Example 1, this example provides an annealing device for large-capacity amorphous three-dimensional iron cores in new energy applications. The inert atmosphere circulation assembly includes a gas supply unit, a gas flow meter, a circulating fan, and an exhaust gas purification unit, wherein: The air supply unit is connected to the air inlet on the three-dimensional adjustable heating cavity via a circulating fan.

[0029] A gas flow meter is installed on the connecting pipeline between the gas supply unit and the air inlet on the three-dimensional adjustable heating cavity.

[0030] The air outlet on the three-dimensional adjustable heating cavity is connected to the air supply unit via the exhaust gas purification unit.

[0031] In this embodiment, during the heat preservation and cooling stages, the circulating gas is continuously purified to adsorb trace amounts of moisture, oxygen, hydrocarbons and other impurities that may be released by the materials or seals, thereby maintaining the purity of the gas inside the cavity.

[0032] In this embodiment, the high-purity inert atmosphere effectively prevents the oxidation and crystallization of the amorphous ribbon.

[0033] Example 4 Based on Example 1, this example provides an annealing device for large-capacity amorphous three-dimensional iron cores in new energy. The magnetic shielding support frame is made of non-magnetic stainless steel and is used to support the iron core and prevent external magnetic fields from interfering with the magnetic domain orientation during the annealing process.

[0034] Example 5 Based on Example 1, this example provides an annealing device for large-capacity amorphous three-dimensional iron cores in new energy applications. The gradient cooling assembly includes a cooling fan and a liquid nitrogen-assisted cooling nozzle, wherein: The outlet of the cooling fan is connected to the cold air inlet of the three-dimensional adjustable heating cavity, which is used to deliver room temperature or low temperature circulating gas into the cavity for basic cooling. The inlets of the multiple liquid nitrogen auxiliary cooling nozzles are connected to a liquid nitrogen source via branch lines, and their outlets merge with the main cooling pipeline, or are directly arranged at a specific cold gas inlet of the three-dimensional adjustable heating cavity.

[0035] In this embodiment, gradient cooling avoids thermal stress concentration and prevents core deformation or cracking.

[0036] Example 6 Based on Example 1, this example provides an annealing device for a large-capacity amorphous three-dimensional iron core for new energy. The annealing device includes an excitation coil installed on the outer wall of a three-dimensional adjustable heating chamber. The excitation coil is connected to an AC power supply to generate a uniform alternating magnetic field with a frequency of 50-400 Hz and an intensity of 0.5-2 Oe that is adjustable.

[0037] In this embodiment, weak magnetic field-assisted annealing significantly improves magnetic permeability and reduces iron loss (typical value: P1.3 / ). 50 ≤ 0.7W / kg).

[0038] Example 7 This embodiment provides an annealing method for large-capacity amorphous three-dimensional iron cores in new energy applications, comprising the following steps: A large-capacity amorphous three-dimensional iron core is placed in a three-dimensional adjustable heating cavity; Adjust the pressure and oxygen content of the three-dimensional adjustable heating chamber to the set range; The temperature of the three-dimensional adjustable heating chamber is raised to the annealing temperature at a set heating rate, and then held at that temperature for a set time. A weak alternating magnetic field is applied during the heat preservation stage to induce the magnetic domains to align in an orderly manner along the magnetic circuit direction; After the heat preservation is completed, the core is cooled to room temperature at a set gradient cooling rate to complete the annealing of the large-capacity amorphous solid iron core.

[0039] Example 8 This embodiment provides an annealing method for large-capacity amorphous three-dimensional iron cores in new energy applications, comprising the following steps: S1. Place the large-capacity amorphous three-dimensional iron core on the magnetic shielding support frame, install it into the three-dimensional adjustable heating cavity, and seal the cavity door of the three-dimensional adjustable heating cavity; S2. Evacuate the three-dimensional adjustable heating chamber to make the pressure inside the three-dimensional adjustable heating chamber ≤10 Pa, and purge it three times with high-purity inert gas to establish a protective atmosphere with an oxygen content ≤10 ppm. S3. Start the heating program: raise the temperature to the annealing temperature T1 (usually 360–420℃) at a heating rate of 1–3℃ / min, and hold for 1–4 hours; S4. During the heat preservation stage, a weak alternating magnetic field with a frequency of 50–400 Hz and an intensity of 0.5–2 Oe is applied to induce the magnetic domains to align in an orderly manner along the magnetic circuit direction; At the annealing temperature, the activity of magnetic domains in amorphous alloys is enhanced. Applying a weak external alternating magnetic field is equivalent to giving the magnetic domains a "guiding force", which causes the easy magnetization axis of the magnetic domains to align along the direction of the external field. This orientation is then "frozen" during the subsequent cooling process, thereby obtaining high permeability along the magnetic circuit direction.

[0040] S5. After the heat preservation is completed, start the gradient cooling program: first cool at a rate of 2–5℃ / min to 50℃ below the Curie temperature, then slowly cool at a rate of 0.5–1℃ / min to 150℃, and finally cool naturally to room temperature; S6. After cooling is complete, release the pressure, open the cavity, and remove the annealed core.

[0041] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. An annealing method for large-capacity amorphous three-dimensional iron cores for new energy applications, characterized in that, Includes the following steps: A large-capacity amorphous three-dimensional iron core is placed in a three-dimensional adjustable heating cavity; Adjust the pressure and oxygen content of the three-dimensional adjustable heating chamber to the set range; The temperature of the three-dimensional adjustable heating chamber is raised to the annealing temperature at a set heating rate, and then held at that temperature for a set time. A weak alternating magnetic field is applied during the heat preservation stage to induce the magnetic domains to align in an orderly manner along the magnetic circuit direction; After the heat preservation is completed, the core is cooled to room temperature at a set gradient cooling rate to complete the annealing of the large-capacity amorphous solid iron core.

2. The annealing method for a large-capacity amorphous three-dimensional iron core for new energy according to claim 1, characterized in that, The pressure value of the three-dimensional adjustable heating chamber is less than or equal to 10 Pa.

3. The annealing method for a large-capacity amorphous three-dimensional iron core for new energy according to claim 1, characterized in that, The oxygen content of the three-dimensional adjustable heating chamber is less than or equal to 10 ppm.

4. The annealing method for a large-capacity amorphous three-dimensional iron core for new energy according to claim 1, characterized in that, The temperature of the three-dimensional adjustable heating chamber is raised to the annealing temperature at a set heating rate, and then held at that temperature for a set time. The specific process parameters are: The temperature of the three-dimensional adjustable heating chamber is raised to the annealing temperature at a heating rate of 1–3℃ / min, and then held at that temperature for 1–4 hours.

5. The annealing method for a large-capacity amorphous three-dimensional iron core for new energy according to claim 1, characterized in that, The weak alternating magnetic field has a frequency of 50–400 Hz and an intensity of 0.5–2 Oe.

6. The annealing method for a large-capacity amorphous three-dimensional iron core for new energy according to claim 1, characterized in that, Cool to room temperature using a set gradient cooling rate. Specific process parameters: First, cool to 50°C below the Curie temperature at a rate of 2–5°C / min; Next, it is slowly cooled to 150°C at a rate of 0.5–1°C / min; Finally, allow it to cool naturally to room temperature.

7. An annealing device for large-capacity amorphous three-dimensional iron cores in new energy applications, characterized in that, The annealing method according to claim 1 includes a three-dimensional adjustable heating cavity, an inert atmosphere circulation assembly, a magnetic shielding support frame, and a gradient cooling assembly, wherein: The magnetic shielding support frame is placed inside the cavity of the three-dimensional adjustable heating cavity to support the amorphous three-dimensional iron core; The outlet of the inert atmosphere circulation assembly is connected to the inlet of the three-dimensional adjustable heating cavity to provide inert gas to the three-dimensional adjustable heating cavity, thereby adjusting the oxygen content in the three-dimensional adjustable heating cavity. The cold air outlet on the gradient cooling component is connected to the cold air inlet of the three-dimensional adjustable heating cavity to provide cooling gas to the three-dimensional adjustable heating cavity.

8. An annealing device for large-capacity amorphous three-dimensional iron cores in new energy applications according to claim 7, characterized in that, The inner cavity of the three-dimensional adjustable heating cavity is divided into a top temperature control zone, a middle temperature control zone and a bottom temperature control zone from top to bottom. Each of the top temperature control zone, the middle temperature control zone and the bottom temperature control zone is equipped with an infrared radiation heating unit. Multiple infrared radiation heating units in the inner cavity are arranged in a three-dimensional symmetrical manner around the amorphous three-dimensional iron core. Each temperature control zone is equipped with multiple thermocouples, which are evenly distributed around the amorphous three-dimensional iron core. The infrared radiation heating unit and thermocouple in each temperature control zone are connected to the PID controller.

9. An annealing device for large-capacity amorphous three-dimensional iron cores in new energy applications according to claim 7, characterized in that, The annealing device includes an excitation coil installed on the outer wall of a three-dimensional adjustable heating chamber, and the excitation coil is connected to an AC power supply.

10. An annealing device for large-capacity amorphous three-dimensional iron cores in new energy applications according to claim 7, characterized in that, The inert atmosphere circulation assembly includes an air supply unit, a circulating fan, and an exhaust gas purification unit, wherein: The air supply unit is connected to the air inlet on the three-dimensional adjustable heating cavity via a circulating fan; The air outlet on the three-dimensional adjustable heating cavity is connected to the air supply unit via the exhaust gas purification unit.