A sample piece heating system applied to a vacuum pressure impregnation process of a large cross-section magnet

Abstract

The application provides a sample piece heating system applied to a vacuum pressure impregnation process of a large-section magnet, relates to the technical field of magnet manufacturing equipment, and comprises a mold, an internal heating power supply and a control system, and an external heating power supply and a control system; the mold is internally provided with an internal heating unit, the internal heating unit comprises a plurality of sample piece conductors; the mold is externally provided with an external heating assembly; the internal heating power supply and the control system are electrically connected with each other, and the external heating power supply and the control system are electrically connected with the external heating assembly. The application overcomes the problem of too complex wiring caused by too many conductors, facilitates personnel to control the electrical system, troubleshoot relevant problem points, and synchronously heat all the conductors, is used for temperature supply in the vacuum pressure impregnation process of the sample piece, makes the temperature process curve of the sample piece consistent with that of the formal product manufacturing, and through low-cost sample piece simulation, process defects are found and avoided in advance, and the probability of problems of the real coil in the later heating is reduced.

Description

Technical Field

[0001] This invention relates to the field of magnet manufacturing equipment technology, and more specifically, to a sample heating system applied to the vacuum pressure impregnation process of large cross-section magnets. Background Technology

[0002] Vacuum pressure impregnation (VPI) is a crucial step in the manufacturing of large coils (magnets). This process solidifies the resin, conductor, and insulation layer into a rigid whole. The VPI-impregnated magnet insulation layer exhibits excellent uniformity and sealing, significantly improving its stability under vacuum and low-temperature environments. During VPI, strict temperature control is essential, adhering to the degassing and resin gel curing temperature profiles to achieve higher product quality. To ensure temperature uniformity and shorten production time, large magnets utilize conductor heating and simultaneous external heating during the VPI process.

[0003] Before manufacturing large coils, to verify the feasibility of the vacuum pressure impregnation process and avoid significant economic losses due to substandard magnet insulation performance, it is typically necessary to manufacture a prototype with the same cross-sectional dimensions for complete process verification, considering different insulation structures and magnet cross-sectional dimensions. This prototype must be consistent with the process route of the final product, with precise temperature control being one of the most critical parameters. The prototype usually selects a section of the magnet for verification. The prototype's conductors are single-path and numerous, leading to overly complex wiring, hindering personnel from adjusting the electrical system, troubleshooting related problems, and ensuring simultaneous heating of all conductors. Summary of the Invention

[0004] The present invention aims to solve the problems in the prior art where the wiring is too complicated due to the excessive number of conductors, making it inconvenient for personnel to control the electrical system, troubleshoot related problems, and simultaneously heat all conductors.

[0005] To address the aforementioned problems, this invention provides a sample heating system for a vacuum pressure impregnation process of large cross-section magnets, comprising a mold, an internal heating power supply and control system, and an external heating power supply and control system. The mold is equipped with multiple internal heating units, each of which contains several sample conductors connected in series to form a closed heating circuit; an external heating assembly is provided on the outside of the mold. The internal heating power supply and control system are electrically connected to each internal heating unit, and the external heating power supply and control system are electrically connected to the external heating component, forming a closed-loop temperature control structure for synchronous and uniform heating of the inside and outside of the mold.

[0006] The present invention provides a sample heating system for vacuum pressure impregnation of large cross-section magnets, which, compared with the prior art, has, but is not limited to, the following beneficial effects: This sample heating system, applied to the vacuum pressure impregnation process of large-section magnets, groups the sample conductors within a mold into multiple heating units. Each inner heating unit contains several sample conductors, which are then connected in series to form a closed heating loop. An external heating assembly is installed outside the mold. An internal heating power supply and control system are electrically connected to each inner heating unit, and an external heating power supply and control system are electrically connected to the external heating assembly, forming a closed-loop temperature control structure. The internal heating unit and its control system independently power and control the temperature inside the mold, while the external heating unit and its control system independently control the temperature outside the mold. The control system has independent power supply and temperature control, and the two systems work together. It adopts a multi-circuit internal and external synchronous heating mode to uniformly heat the inside and outside of the mold at the same time, so as to achieve uniform temperature rise. This overcomes the problem of overly complicated wiring caused by a large number of conductors, which makes it easier for personnel to control the electrical system, troubleshoot related problems, and simultaneously heat all conductors. It is used for temperature supply during the vacuum pressure impregnation process of the sample, so that the temperature process curve of the sample is consistent with that of the final product manufacturing. Furthermore, through low-cost sample simulation, process defects can be detected and avoided in advance, reducing the probability of problems occurring in the actual coil during heating later, making the simulation meaningful.

[0007] Furthermore, the mold includes an inner mold and an outer mold. Multiple inner heating units are installed inside the inner mold, and the outer heating components are installed outside the outer mold. The inner mold is made of stainless steel plate and forms an independent, sealed, and high-vacuum-capable closed chamber inside. The outer mold is made of carbon steel and is fitted outside the inner mold to protect the closed chamber of the inner mold.

[0008] Furthermore, each of the internal heating units includes an electrically connected copper plate and an electrode. Several sample conductors in each internal heating unit are arranged in a rectangular array. The sample conductors include an electrode conductor, several heating rod conductors, and several thermocouple conductors. The electrode conductor and the several heating rod conductors are connected in series through the electrically connected copper plate to form a closed heating circuit. The electrode is connected to the electrically connected copper plate and the internal heating power supply and control system, respectively.

[0009] Furthermore, both the heating rod conductor and the electrode conductor have screws at their ends, and locking nuts are threaded onto the screws. The heating rod conductor includes a heating rod and a first cast aluminum shell. The heating rod is integrally formed inside the first cast aluminum shell. The screws are connected to the heating rods. Through holes that mate with the screws are provided on the electrical connection copper plate.

[0010] Furthermore, the thermocouple conductor includes a second cast aluminum shell and a platinum resistance thermometer. A protective sleeve is pre-embedded inside the second cast aluminum shell, and the platinum resistance thermometer is assembled inside the protective sleeve to collect internal temperature data in real time and convert it into an electrical signal that is transmitted to the internal heating power supply and control system via a lead wire.

[0011] Furthermore, a locking bolt is threaded onto the second cast aluminum housing, the end of which is pressed against the outside of the platinum resistance thermometer to limit its movement.

[0012] Furthermore, the external heating assembly includes an insulation blanket and multiple heating plates, the multiple heating plates being fitted and installed around the outer wall of the outer mold, and the insulation blanket covering the outside of the multiple heating plates.

[0013] Furthermore, the heating plate is a cast aluminum plate structure with a heating tube embedded inside and a wiring stud on the outside. The heating tube is connected to an external heating power supply and control system through the wiring stud. Furthermore, a temperature sensor is fixedly installed on the heating plate to collect external temperature data in real time and convert it into an electrical signal, which is then transmitted to the external heating power supply and control system via leads.

[0014] Furthermore, the insulation blanket adopts a high-temperature resistant multi-layer composite structure, with an outer layer of protective heat-resistant cloth and an inner layer of high-efficiency heat-insulating cotton. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the sample heating system applied to the vacuum pressure impregnation process of large cross-section magnets according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the internal heating unit according to an embodiment of the present invention; Figure 3 Embodiments of the present invention Figure 2 A magnified view of position A in the image; Figure 4 This is a schematic diagram showing the position of the conductor in the sample according to an embodiment of the present invention; Figure 5 Embodiments of the present invention Figure 3 A schematic diagram of the structure of the heating rod conductor in the diagram; Figure 6 Embodiments of the present invention Figure 5 A cross-sectional view of the BB position in the diagram; Figure 7 This is a schematic diagram of the structure of a thermocouple conductor according to an embodiment of the present invention; Figure 8 Embodiments of the present invention Figure 7 A cross-sectional view of the CC position in the diagram; Figure 9Embodiments of the present invention Figure 1 The left view.

[0016] Explanation of reference numerals in the attached figures: 1. Mold; 101. Inner mold; 102. Outer mold; 2. Internal heating power supply and control system; 3. External heating power supply and control system; 4. Internal heating unit; 401. Thermocouple conductor; 4011. Second cast aluminum shell; 4012. Platinum resistance thermometer; 4013. Protective sleeve; 4014. Locking bolt; 402. Heating rod conductor; 4021. Heating rod; 4022. First cast aluminum shell; 403. Electrode conductor; 404. Electrical connection copper plate; 405. Electrode; 5. External heating assembly; 501. Insulation blanket; 502. Heating plate; 6. Locking nut; 7. Screw. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, specific embodiments of this application are described clearly and completely below with reference to the accompanying drawings. It should be understood that the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments described in this application without creative effort will fall within the scope of protection of this application.

[0018] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the specification of this application is for the purpose of describing specific embodiments only and is not intended to limit this application; the terms "comprising," "including," "having," "containing," "comprise," etc., in the specification, claims, and accompanying drawings of this application are open-ended terms, indicating that a method comprises one or more steps, or an apparatus comprises one or more elements, but do not exclude the inclusion of other steps or elements. The terms "first," "second," etc., in the specification, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or primary / secondary relationship. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0019] In the description of this application, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0020] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0021] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0022] See Figure 1 The present invention provides a sample heating system for a vacuum pressure impregnation process of large cross-section magnets, comprising a mold 1, an internal heating power supply and control system 2, and an external heating power supply and control system 3. The mold 1 is equipped with multiple internal heating units 4, each internal heating unit 4 containing several sample conductors, which are connected in series to form a closed heating circuit; the mold 1 is equipped with an external heating assembly 5. The internal heating power supply and control system 2 is electrically connected to each internal heating unit 4, and the external heating power supply and control system 3 is electrically connected to the external heating component 5, forming a closed-loop temperature control structure for synchronous and uniform heating of the inside and outside of the mold 1.

[0023] In this embodiment, the sample heating system applied to the vacuum pressure impregnation process of large cross-section magnets divides the sample conductors into multiple heating units 4 within the mold 1, with each inner heating unit 4 containing several sample conductors. These conductors are then connected in series to form a closed heating loop. An external heating assembly 5 is installed outside the mold 1. An internal heating power supply and control system 2 is electrically connected to each inner heating unit 4, and an external heating power supply and control system 3 is electrically connected to the external heating assembly 5, forming a closed-loop temperature control structure. The internal heating power supply and control system 2 independently power and control the temperature inside the mold 1, while the external heating assembly 5 provides independent temperature control for the outside of the mold 1. The external heating power supply and control system 3 provide independent power supply and temperature control. The two systems work together and adopt a multi-circuit internal and external synchronous heating mode to uniformly heat the mold 1 inside and out, thereby overcoming the problem of overly complex wiring caused by a large number of conductors. This facilitates personnel to control the electrical system, troubleshoot related problems, and ensures synchronous heating of all conductors for temperature supply during the vacuum pressure impregnation process of the sample. This ensures that the temperature process curve of the sample is consistent with that of the final product. Furthermore, through low-cost sample simulation, process defects can be detected and avoided in advance, reducing the probability of problems occurring during heating of the real coil later, making the simulation meaningful.

[0024] It should be noted that the external heating power supply and control system 3 has an independent and precise temperature control function, which can work together with the internal heating power supply and control system 2 to effectively reduce the temperature difference between the inside and outside of the coil, ensure uniform and stable temperature throughout the VPI impregnation and curing process, and ensure the smooth completion of the VPI impregnation process of the sample.

[0025] See Figure 1 Optionally, the mold 1 includes an inner mold 101 and an outer mold 102. Multiple internal heating units 4 are installed inside the inner mold 101, and external heating components 5 are installed outside the outer mold 102. The inner mold 101 is made of stainless steel plate and welded together to form an independent, sealed, and high-vacuum-capable closed chamber. The outer mold 102 is made of carbon steel and is fitted outside the inner mold 101 to protect the closed chamber of the inner mold 101.

[0026] In this embodiment, an external heating component 5 is installed on the outside of the outer mold 102 to heat the outside of the outer mold 102, and multiple internal heating units 4 are installed inside the inner mold 101 to heat the inside of the inner mold 101. The inner mold 101 is made of stainless steel plate, such as 2mm thick stainless steel plate, so that the inside of the inner mold 101 forms an independent, sealed, and high-vacuum-capable closed chamber. After high vacuum is drawn, it is convenient to seal the conductor of the sample, and at the same time, it limits the shape and structural size of the sample casting. The outer mold 102 is made of carbon steel and is fitted on the outside of the inner mold 101. This makes it convenient for the outer mold 102 to protect the closed chamber after high vacuum is drawn during the vacuum pressure impregnation (VPI) heating process, prevent the inner mold 101 from deforming, and improve the stability of the closed chamber after high vacuum is drawn.

[0027] See Figures 2-4 Optionally, each internal heating unit 4 includes an electrically connected copper plate 404 and an electrode 405. Several sample conductors in each internal heating unit 4 are arranged in a rectangular array. The sample conductors include an electrode conductor 403, several heating rod conductors 402 and several thermocouple conductors 401. The electrode conductor 403 and several heating rod conductors 402 are connected in series through the electrically connected copper plate 404 to form a closed heating circuit. The electrode 405 is connected to the electrically connected copper plate 404 and the internal heating power supply and control system 2, respectively.

[0028] In this embodiment, for example, four internal heating units 4 are provided inside the inner mold 101. A rectangular array of sample conductors is arranged in each internal heating unit 4. For example, 78 sample conductors are used in each internal heating unit 4, including one electrode conductor 403, four thermocouple conductors 401, and seventy-three heating rod conductors 402. The four thermocouple conductors 401 and the seventy-three heating rod conductors 402 are connected in series via an electrical connection copper plate 404 to form a closed heating circuit. Electrodes 405 are then used to connect the electrical connection copper plate 404 to the internal heating power supply and control system 2. After power is applied, the heating circuit is energized through the electrode conductors 403... As the current inlet and outlet carrier of the series heating circuit, it receives the power supply current connected to the external electrode 405 and distributes the current evenly to all the series-connected heating rod conductors 402 in the unit to form a complete closed heating circuit. After the heating rod conductors 402 are energized, they generate stable heat through electric heating. By dividing the numerous sample conductors into multiple independent internal heating units 4, the sample conductors in the unit are connected in series through the copper plate 404, forming multiple independent heating circuits (because the sample conductors are single-path and numerous, the entire winding is divided into multiple circuits for heating), which facilitates uniform heating inside the inner mold 101.

[0029] It should be noted that high-temperature conductive grease is applied to the contact surfaces of the electrical connection copper plate 404 with the conductor end of the sample and the electrode 405, which effectively reduces contact resistance, prevents oxidation and overheating of the contact surface, and improves conductivity stability. Polyimide tape is used to wrap and fix the connection of the electrode 405, with the other end exposed to connect to the internal heating power supply and control system 2, to ensure the stability of the electrode 405 connection. After sealing the electrode 405 and the inner mold 101, a multimeter is used to measure the wrapped electrode 405 and the inner mold 101 to ensure that they are disconnected.

[0030] See Figure 5 and Figure 6 Optionally, both the heating rod conductor 402 and the electrode conductor 403 are provided with screws 7 at their ends, and locking nuts 6 are threaded onto the screws 7. The heating rod conductor 402 includes a heating rod 4021 and a first cast aluminum shell 4022. The heating rod 4021 is integrated into the first cast aluminum shell 4022 and integrally formed. The screws 7 are connected to the heating rod 4021. The electrical connection copper plate 404 has through holes that cooperate with the screws 7.

[0031] In this embodiment, the screws 7 at the ends of the heating rod conductor 402 and the electrode conductor 403 are passed through the corresponding through holes on the electrical connection copper plate 404 and then locked in place with the locking nut 6. This facilitates the connection of each heating rod conductor 402 and electrode conductor 403 in the inner heating unit 4 to form a complete closed heating circuit (e.g., Figure 3 As shown), the heating rod 4021 (including heating wire, magnesium oxide layer and sleeve) is integrated into the first cast aluminum housing 4022 and integrally formed into the heating rod conductor 402 (the heating rod conductor 402 has the same cross-section as the actual coil). After being energized, the heating rod 4021 heats the inside of the coil. The heat is transferred from the inside to the outside layer to the insulation layer and the entire cavity, providing a stable internal heat source for the VPI process of the sample. Furthermore, by adopting an integral molding process to integrate the heating rod 4021 and the first cast aluminum housing 4022, the processing technology can be effectively simplified and the production cost can be reduced.

[0032] See Figure 7 and Figure 8 Optionally, the thermocouple conductor 401 includes a second cast aluminum housing 4011 and a platinum resistance thermometer 4012. A protective sleeve 4013 is pre-embedded inside the second cast aluminum housing 4011. The platinum resistance thermometer 4012 is assembled inside the protective sleeve 4013 and is used to collect internal temperature data in real time and convert it into an electrical signal, which is transmitted to the internal heating power supply and control system 2 through the lead wire.

[0033] In this embodiment, in each internal heating unit 4, a thermocouple conductor 401 is placed at a key temperature measurement point inside the coil as a high-precision temperature sensor. When the thermocouple conductor 401 (which has the same specifications as the actual coil conductor cross-section) is working, the internal temperature data of the inner mold 101 is collected in real time by the platinum resistance thermometer 4012 and the temperature signal is converted into an electrical signal and transmitted to the internal heating power supply and control system 2 through the lead wire, forming an independent closed-loop temperature control (i.e., using PID closed-loop precise temperature control). The internal heating power supply and control system 2 dynamically adjusts the power supply voltage and current parameters according to the real-time temperature data transmitted by the platinum resistance thermometer 4012, so that the internal temperature rise of the sample strictly follows the preset process curve.

[0034] See Figure 7 and Figure 8 Optionally, a locking bolt 4014 is threaded onto the second cast aluminum housing 4011. The end of the locking bolt 4014 is externally pressed into the platinum resistance thermometer 4012 to limit the position of the platinum resistance thermometer 4012.

[0035] In this embodiment, the thermocouple conductor 401 is based on a second cast aluminum housing 4011, in which a protective sleeve 4013 is pre-embedded. The thermocouple conductor 401 is then installed inside the housing and protected by the protective sleeve 4013. The locking bolt 4014 is tightened by screwing on the second cast aluminum housing 4011 through a threaded connection, so that its end is pressed against the outside of the platinum resistance thermometer 4012, limiting and fixing it to prevent the platinum resistance thermometer 4012 from shifting.

[0036] See Figure 1 and Figure 9 Optionally, the external heating component 5 includes an insulation blanket 501 and multiple heating plates 502. The multiple heating plates 502 are fitted and installed around the outer wall of the outer mold 102, and the insulation blanket 501 covers the outside of the multiple heating plates 502.

[0037] In this embodiment, multiple heating plates 502 are used and attached to the outer wall of the outer mold 102. When the multiple heating plates 502 are heating, efficient heat conduction is ensured, which facilitates heating the outside of the outer mold 102. Then, the heating plates 502 are covered with a heat insulation blanket 501, which plays a good role in heat insulation, reduces heat loss, and improves heating efficiency. Thus, the outer mold 102 is heated by the cooperation of the heating plates 502 and the heat insulation blanket 501. The thermocouple conductor 401 and the heating rod conductor 402 are connected in series through the copper plate 404 to form a closed heating circuit for heating in the inner mold 101, so as to achieve uniform heating of the entire coil.

[0038] See Figure 1Optionally, the heating plate 502 is a cast aluminum plate structure with a heating tube embedded inside and a wiring stud on the outside. The heating tube is connected to the external heating power supply and control system 3 through the wiring stud. In this embodiment, a heating tube is pre-embedded inside a cast aluminum plate structure. The heating tube is then connected to an external heating power supply and control system 3 via wiring studs on the outside of the cast aluminum plate structure. After power is applied, the heating tube generates stable heat through electric heating, which allows multiple heating plates 502 to uniformly heat the outside of the outer mold 102. The heat is then uniformly transferred layer by layer from the outer mold 102 and the inner mold 101 to the entire closed chamber, providing a stable external heat source for the VPI process of the sample.

[0039] Optionally, a temperature sensor is fixedly installed on the heating plate 502 to collect external temperature data in real time and convert it into an electrical signal, which is then transmitted to the external heating power supply and control system 3 via a lead wire.

[0040] In this embodiment, a temperature sensor is fixedly installed on the heating plate 502 to collect the temperature data of the outer wall of the outer mold 102 in real time and convert the temperature signal into an electrical signal, which is then transmitted to the external heating power supply and control system 3 through a lead wire, forming an independent closed-loop temperature control. The external heating power supply and control system 3 analyzes and processes the real-time temperature data transmitted from the temperature sensor and uses it as the core basis for automatically adjusting the output power of the heating plate 502, thereby accurately controlling the temperature rise rate of the heating plate 502, maintaining a constant temperature, and ensuring that the external heating temperature is stable and controllable.

[0041] It should be noted that the external heating power supply in the external heating power supply and control system 3 and the internal heating power supply and control system 2 are adapted to the power requirements of the external heating plate 503 and the internal heating rod conductor 402, respectively, and provide independent power to the two heating systems. Both the internal and external heating power supplies adopt a voltage and current stabilization design, and form a closed-loop linkage with the platinum resistance thermometer 4012, the temperature sensor and the corresponding control system. Based on the real-time received temperature signal, the power supply parameters are automatically adjusted to make the actual temperature rise curve close to the preset temperature rise curve. At the same time, the internal and external heating power supplies have safety protection functions such as over-temperature and over-current protection.

[0042] See Figure 1 Optionally, the thermal insulation blanket 501 adopts a high-temperature resistant multi-layer composite structure, with an outer layer of protective heat-resistant cloth and an inner layer of high-efficiency heat-insulating cotton.

[0043] In this embodiment, the thermal insulation blanket 501 adopts a high-temperature resistant multi-layer composite structure. The outer layer uses a protective heat-resistant cloth, and the inner layer is filled with high-efficiency heat insulation cotton, which can effectively block heat loss, reduce heat loss, reduce temperature fluctuations, and ensure the stability of the coil VPI impregnation temperature.

[0044] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A sample heating system for use in vacuum pressure impregnation processes of large cross-section magnets, characterized in that, Includes mold (1), internal heating power supply and control system (2), and external heating power supply and control system (3); The mold (1) is provided with multiple internal heating units (4), each of the internal heating units (4) contains several sample conductors, which are connected in series to form a closed heating circuit; the mold (1) is provided with an external heating assembly (5). The internal heating power supply and control system (2) is electrically connected to each internal heating unit (4), and the external heating power supply and control system (3) is electrically connected to the external heating component (5), forming a closed-loop temperature control structure for synchronous and uniform heating of the mold (1) inside and out.

2. The sample heating system for vacuum pressure impregnation process of large cross-section magnets according to claim 1, characterized in that, The mold (1) includes an inner mold (101) and an outer mold (102). Multiple inner heating units (4) are installed inside the inner mold (101), and the outer heating components (5) are installed outside the outer mold (102). The inner mold (101) is made of stainless steel plate and has an independent, sealed, and high-vacuum-capable closed chamber inside. The outer mold (102) is made of carbon steel and is fitted outside the inner mold (101) to protect the closed chamber of the inner mold (101).

3. The sample heating system for vacuum pressure impregnation process of large cross-section magnets according to claim 2, characterized in that, Each of the internal heating units (4) includes an electrical connection copper plate (404) and an electrode (405). Several sample conductors in each of the internal heating units (4) are arranged in a rectangular array. Several sample conductors include an electrode conductor (403), several heating rod conductors (402) and several thermocouple conductors (401). The electrode conductor (403) and several heating rod conductors (402) are connected in series through the electrical connection copper plate (404) to form a closed heating circuit. The electrode (405) is connected to the electrical connection copper plate (404) and the internal heating power supply and control system (2) respectively.

4. The sample heating system for vacuum pressure impregnation process of large cross-section magnets according to claim 3, characterized in that, Both the heating rod conductor (402) and the electrode conductor (403) are provided with screws (7) at their ends. A locking nut (6) is threaded onto the screw (7). The heating rod conductor (402) includes a heating rod (4021) and a first cast aluminum shell (4022). The heating rod (4021) is integrally formed inside the first cast aluminum shell (4022). The screw (7) is connected to the heating rod (4021). The electrical connection copper plate (404) has through holes that cooperate with the screw (7).

5. The sample heating system for vacuum pressure impregnation process of large cross-section magnets according to claim 4, characterized in that, The thermocouple conductor (401) includes a second cast aluminum shell (4011) and a platinum resistance thermometer (4012). A protective sleeve (4013) is pre-embedded inside the second cast aluminum shell (4011). The platinum resistance thermometer (4012) is assembled inside the protective sleeve (4013) and is used to collect internal temperature data in real time and convert it into an electrical signal, which is transmitted to the internal heating power supply and control system (2) through the lead wire.

6. The sample heating system for vacuum pressure impregnation process of large cross-section magnets according to claim 5, characterized in that, The second cast aluminum housing (4011) is threaded with a locking bolt (4014), the end of which is pressed into the outside of the platinum resistance thermometer (4012) to limit the position of the platinum resistance thermometer (4012).

7. The sample heating system for vacuum pressure impregnation process of large cross-section magnets according to claim 2, characterized in that, The external heating component (5) includes an insulation blanket (501) and multiple heating plates (502). The multiple heating plates (502) are fitted and installed around the outer wall of the outer mold (102). The insulation blanket (501) covers the outside of the multiple heating plates (502).

8. The sample heating system for vacuum pressure impregnation process of large cross-section magnets according to claim 7, characterized in that, The heating plate (502) is a cast aluminum plate structure with a heating tube embedded inside and a wiring stud on the outside. The heating tube is connected to the external heating power supply and control system (3) through the wiring stud.

9. The sample heating system for vacuum pressure impregnation process of large cross-section magnets according to claim 8, characterized in that, A temperature sensor is fixedly installed on the heating plate (502) to collect external temperature data in real time and convert it into an electrical signal, which is then transmitted to the external heating power supply and control system (3) via a lead wire.

10. The sample heating system for vacuum pressure impregnation process of large cross-section magnets according to claim 7, characterized in that, The thermal insulation blanket (501) adopts a high-temperature resistant multi-layer composite structure, with the outer layer being a protective heat-resistant cloth and the inner layer being a high-efficiency heat-insulating cotton.

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