Oil-immersed inverted current transformer vacuum drying and oiling device and use method

Abstract

The application discloses an oil-immersed inverted current transformer vacuum drying and oil injection device and a use method thereof. The device comprises a vacuum tank for accommodating an oil-immersed inverted current transformer; a drying system in communication with the vacuum tank and configured to deliver drying medium steam into the vacuum tank for drying treatment through condensation and phase change heat release of the drying medium steam on the surface of the oil-immersed inverted current transformer; and an oil injection system comprising an oil injection pipeline extending through the side wall of the vacuum tank to the inside of the vacuum tank. The oil-immersed inverted current transformer vacuum drying and oil injection device is configured to sequentially perform drying treatment and oil injection operation under the vacuum state in the vacuum tank. The application realizes continuous drying treatment and oil injection operation of the oil-immersed inverted current transformer in the same vacuum environment, improves production efficiency and ensures product quality.

Description

Technical Field

[0001] This invention relates to the field of drying and oil filling technology for current transformers, and particularly to a vacuum drying and oil filling device and its usage method for an oil-immersed inverted current transformer. Background Technology

[0002] Currently, in the manufacturing process of oil-immersed inverted current transformers, insulation drying and vacuum oil filling processes directly affect the product's electrical performance. Existing drying and oil filling methods typically use air as the drying medium, employing hot air circulation or transformer methods within a vacuum tank for drying. However, traditional air-based drying methods suffer from low heating efficiency, long drying times, and difficulty in penetrating deep into the insulation layer, leading to uneven drying. Furthermore, in traditional processes, the drying and oil filling steps are often performed separately. After drying, equipment needs to be transferred or the vacuum environment broken for final assembly and oil filling. This process is not only time-consuming but also prone to secondary moisture absorption of the insulation material during transfer, affecting product quality. Therefore, there is an urgent need for an integrated drying and oil filling device and method that can improve drying efficiency, shorten the process flow, and effectively prevent insulation moisture absorption. Summary of the Invention

[0003] The purpose of this invention is to provide a vacuum drying and oil injection device and method for oil-immersed inverted current transformers, so as to solve the problems of low drying efficiency, cumbersome procedures and easy insulation moisture in the prior art. This invention realizes continuous drying and oil injection of oil-immersed inverted current transformers under the same vacuum environment, which improves production efficiency and ensures product quality.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A vacuum drying and oil injection device for an oil-immersed inverted current transformer includes: Vacuum tank for housing oil-immersed inverted current transformers; A drying system, connected to the vacuum tank, is configured to deliver drying medium vapor into the vacuum tank, and to perform drying treatment by condensing the drying medium vapor on the surface of the oil-immersed inverted current transformer and releasing heat through a phase change. The oil injection system includes an oil injection pipeline that extends through the side wall of the vacuum tank into the interior of the vacuum tank. The oil-immersed inverted current transformer vacuum drying and oil injection device is configured to sequentially perform drying and oil injection operations while maintaining a vacuum state inside the vacuum tank.

[0005] Furthermore, the drying system is a kerosene vapor-phase drying system, configured to heat kerosene to generate kerosene vapor as the drying medium vapor.

[0006] Furthermore, the kerosene vapor phase drying system includes: A kerosene heating assembly configured to heat kerosene to generate kerosene vapor; A condensation recovery component, connected to the vacuum tank, is configured to condense kerosene vapor in the vacuum tank into liquid kerosene and recycle it. The kerosene heating assembly is connected to the vacuum tank via a pipeline to deliver the generated kerosene vapor into the vacuum tank.

[0007] Furthermore, the oil filling line is configured to extend into the vacuum tank and connect to the oil filling port of the oil-immersed inverted current transformer.

[0008] Furthermore, the oil injection system also includes: Oil storage tanks are used to store insulating oil; An oil injection pump is installed on the oil injection pipeline and is configured to transport insulating oil in the oil storage tank to the inside of the oil-immersed inverted current transformer through the oil injection pipeline. One end of the oil injection pipeline is connected to the oil storage tank, and the other end extends through the side wall of the vacuum tank into the interior of the vacuum tank.

[0009] Furthermore, it also includes a temperature control system configured to detect and adjust the temperature inside the vacuum tank and the heating temperature of the drying system.

[0010] Furthermore, it also includes a control unit, which is electrically connected to the drying system and the oiling system and configured to control the drying system and the oiling system to operate in coordination.

[0011] A method for using a vacuum drying and oil injection device for an oil-immersed inverted current transformer includes: The oil-immersed inverted current transformer is placed inside a vacuum chamber; The vacuum container is evacuated. While maintaining a vacuum state inside the vacuum tank, a drying medium vapor is supplied into the vacuum tank through a drying system for drying treatment. After the drying process is completed, while the vacuum tank is kept under vacuum, an oil injection operation is performed through the oil injection system. The oil injection operation is to inject insulating oil into the oil-immersed inverted current transformer. Release the pressure inside the vacuum tank and remove the oil-immersed inverted current transformer.

[0012] Furthermore, after the drying process is completed, the oil injection operation is performed directly in the vacuum tank while maintaining a vacuum state, and the vacuum degree in the vacuum tank is maintained continuously between the drying process and the oil injection operation.

[0013] Furthermore, the drying process is carried out at a temperature range of 120°C to 135°C.

[0014] Compared with the prior art, the present invention has the following beneficial technical effects: This invention uses dry medium steam (such as kerosene steam) to condense and release heat on the surface of an oil-immersed inverted current transformer. The heat exchange intensity is much higher than that of traditional hot air circulation, and the heating rate is fast. The steam can penetrate the dead corners and deep layers of the oil-immersed inverted current transformer to achieve synchronous heating inside and outside. The overall temperature difference is extremely small, avoiding the problem of hot air being difficult to penetrate.

[0015] This invention uses a vacuum tank as both a drying container and an oil filling container, achieving integrated drying and oil filling operations. It eliminates the need to transfer the oil-immersed inverted current transformer midway, avoiding secondary pollution and insulation dampness after drying, and significantly improving operational efficiency and processing quality.

[0016] This invention can raise the heating temperature to 120-135℃ in a vacuum environment, ensuring oxygen-free and non-aging insulation, significantly increasing the moisture diffusion rate, and ultimately resulting in lower moisture content; the entire process is in oxygen-free vacuum, protecting the insulation material from oxidation and aging, and combining cleaning and protection functions.

[0017] The condensation recovery assembly of the present invention can recycle the drying medium (such as kerosene), reducing raw material waste, lowering production costs and avoiding environmental pollution. Attached Figure Description

[0018] The accompanying drawings are provided to further understand the invention and constitute a part of this invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0019] Figure 1 This is a schematic diagram of a vacuum drying and oil injection device for an oil-immersed inverted current transformer according to the present invention.

[0020] The components include: 1. Vacuum tank; 2. Oil-immersed inverted current transformer; 3. Kerosene heating assembly; 4. Condensation recovery assembly; 5. Oil storage tank; 6. Oil injection pump; 7. Temperature control system; 8. Control unit; 9. Signal cable; 10. Vacuum pump set; 11. Sealing strip; 12. Vacuum tank door. Detailed Implementation

[0021] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0022] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0023] Example 1 like Figure 1 As shown, this embodiment provides a vacuum drying and oil injection device for an oil-immersed inverted current transformer, including a vacuum tank 1, a drying system, and an oil injection system. The vacuum tank 1 is used to house the oil-immersed inverted current transformer 2; the drying system is connected to the vacuum tank 1 and configured to supply drying medium vapor into the vacuum tank 1, whereby the drying medium vapor condenses and undergoes a phase change, releasing heat on the surface of the oil-immersed inverted current transformer 2 for drying treatment; the oil injection system includes an oil injection pipeline that extends through the side wall of the vacuum tank 1 into the interior of the vacuum tank 1; wherein, the vacuum drying and oil injection device for the oil-immersed inverted current transformer is configured to sequentially perform drying and oil injection operations while maintaining a vacuum state within the vacuum tank 1.

[0024] The vacuum tank 1, serving as the container for the entire process, possesses excellent sealing performance, maintaining an internal vacuum environment. It includes the tank body and the vacuum tank door 12, which are sealed together by a sealing strip 11. An oil-immersed inverted current transformer 2 is placed inside the vacuum tank 1.

[0025] The drying system is connected to the interior of vacuum tank 1 via pipelines. During the drying stage, the drying system generates drying medium vapor and delivers it into vacuum tank 1. The drying medium vapor referred to here is a gaseous medium capable of undergoing a phase change at a specific temperature. When the high-temperature drying medium vapor comes into contact with the cooler surface of the oil-immersed inverted current transformer 2, condensation occurs, changing from a gaseous state to a liquid state, while releasing a large amount of latent heat of phase change. This phase change heat release method has significant advantages compared to traditional hot air convection heating: firstly, the drying medium vapor can penetrate deep into the oil-immersed inverted current transformer 2 and into dead corners, achieving uniform heating and avoiding the external heat and internal cold phenomenon present in hot air heating; secondly, the heat release intensity of the latent heat of phase change is large, which can significantly improve the heating rate and drying efficiency. The drying medium can be selected in various ways, such as kerosene vapor, water vapor, or other organic solvent vapors, as long as its physical properties meet the requirement of being able to condense and release heat in a vacuum environment without damaging the oil-immersed inverted current transformer 2. Preferably, kerosene vapor is used in this invention.

[0026] One of the core components of the oil injection system is the oil injection pipeline. One end of the oil injection pipeline is located outside the vacuum tank 1, used to connect to the insulating oil source, while the other end extends through the side wall of the vacuum tank 1 into its interior. This design, extending through the side wall, is one of the key structural features of this embodiment. With this design, the oil injection pipeline can be directly connected to the oil injection port of the oil-immersed inverted current transformer 2 inside the vacuum tank 1, thus enabling the injection of insulating oil without opening the vacuum tank door 12 or disrupting the vacuum environment. This ensures that the oil injection operation can be seamlessly performed after the drying process, avoiding the problem of secondary moisture absorption of the insulating material caused by equipment transfer or vacuum breaking in traditional processes.

[0027] The oil-immersed inverted current transformer vacuum drying and oil injection device in this embodiment is configured to sequentially perform drying and oil injection operations while maintaining a vacuum state within the vacuum tank 1. That is, from the start of vacuuming, through the drying process, until the oil injection is completed, the vacuum level within the vacuum tank 1 is maintained within a set range, with no vacuum breaking in between. This integrated structural design and process flow arrangement enables continuous operation of drying and oil injection, significantly shortening the process cycle and fundamentally eliminating the risk of moisture absorption in intermediate stages, thus improving the quality of the processed product.

[0028] Example 2 Based on Embodiment 1, this embodiment further defines the specific form of the drying system. The drying system is a kerosene vapor-phase drying system, configured to heat kerosene to generate kerosene vapor as the drying medium vapor. The kerosene vapor-phase drying system includes a kerosene heating component 3 and a condensation recovery component 4. The kerosene heating component 3 is configured to heat kerosene to generate kerosene vapor; the condensation recovery component 4 is connected to a vacuum tank 1 and configured to condense the kerosene vapor in the vacuum tank 1 into liquid kerosene for recycling; wherein, the kerosene heating component 3 is connected to the vacuum tank 1 through a pipeline to transport the generated kerosene vapor into the vacuum tank 1.

[0029] More specifically, the kerosene heating assembly 3 typically includes an evaporator. Inside the evaporator, liquid kerosene is heated to a boiling state, generating high-temperature kerosene vapor. Because the saturated vapor pressure of kerosene in a vacuum environment is much lower than that of water, and its latent heat of vaporization is relatively large, kerosene vapor serves as an excellent drying medium, carrying a significant amount of heat into the vacuum tank 1. Once inside the vacuum tank 1 through the pipeline, the kerosene vapor possesses extremely strong penetrating power, reaching deep into the insulating material and structural dead zones of the oil-immersed inverted current transformer 2. When the kerosene vapor comes into contact with the cooler surface of the insulating material, a condensation phase change occurs, transforming from a gaseous state to a liquid state, releasing a substantial latent heat of condensation. This phase change heat release method is fundamentally different from traditional hot air convection heating: hot air heating only reaches the surface and has low thermal efficiency; while kerosene vapor phase change heat release achieves uniform heating without dead zones and has an extremely high heat exchange coefficient, rapidly increasing the internal temperature of the insulating material and significantly improving the diffusion rate of moisture.

[0030] The condensation recovery assembly 4 constitutes a closed-loop circulation system for the drying medium. The condensation recovery assembly 4 typically includes a condenser and a collection tank. After the kerosene vapor completes its exothermic condensation in the vacuum tank 1, the mixed gas (containing water vapor and a small amount of uncondensed kerosene vapor) is extracted from the vacuum tank and enters the condenser. In the condenser, the kerosene vapor and water vapor are cooled and liquefied. Due to the different densities of kerosene and water and their immiscibility, they naturally separate into layers in the collection tank. The upper layer is liquid kerosene, and the lower layer is water. The liquid kerosene is transported back to the kerosene heating assembly 3 through pipelines for reheating and reuse, thus realizing the recycling of the drying medium. This design not only reduces operating costs but also avoids environmental pollution caused by kerosene emissions.

[0031] It should be understood that although kerosene is used as the preferred drying medium in this embodiment, the choice of drying medium is not limited to this in practical applications. Any organic solvent vapor that can dry insulating materials through phase change exothermicly in a vacuum environment without impairing the properties of the insulating materials should be within the scope of protection of this invention. Furthermore, the specific structural form of the kerosene heating assembly can also vary; it can employ a heating tank with a built-in heater or a circulating heating method using an external heat exchanger, as long as it can achieve the function of generating stable kerosene vapor.

[0032] Example 3 Based on Embodiment 1, this embodiment provides a detailed description of the specific structure of the oil injection system. The oil injection pipeline is configured to extend into the vacuum tank 1 and connect to the oil injection port of the oil-immersed inverted current transformer 2. Specifically, after penetrating the side wall of the vacuum tank 1, a section of pipeline is reserved inside the vacuum tank 1. The end of this pipeline is equipped with a quick connector or flange interface for sealing connection with the oil injection port of the oil-immersed inverted current transformer 2. This design, which directly connects the oil injection port inside the vacuum tank 1, allows insulating oil to be directly injected into the oil-immersed inverted current transformer 2, avoiding splashing and uneven oil-gas mixing during the oil injection process. It also provides the necessary physical channel for oil injection in a vacuum environment.

[0033] Furthermore, the oil injection system also includes an oil storage tank 5 and an oil injection pump 6. The oil storage tank 5 stores insulating oil; the oil injection pump 6 is located on the oil injection pipeline and is configured to transport the insulating oil from the oil storage tank 5 to the inside of the oil-immersed inverted current transformer 2 via the oil injection pipeline. One end of the oil injection pipeline is connected to the oil storage tank 5, and the other end extends through the side wall of the vacuum tank 1 into the interior of the vacuum tank 1. The oil storage tank 5 is typically located outside the vacuum tank for easy observation of the oil level and replenishment of insulating oil. The oil injection pump 6, as a power source, is located on the oil injection pipeline outside the vacuum tank 1. After drying, the vacuum tank 1 is maintained at a high vacuum, while the oil storage tank 5 is at atmospheric pressure or a slight positive pressure. After the oil injection pump 6 is started, it stably pressurizes the insulating oil into the inside of the oil-immersed inverted current transformer 2. In addition, the oil injection pump 6 can be used in conjunction with a flow meter or control valve to achieve precise control of the oil injection speed and quantity. In this embodiment, the oil storage tank 5, the oil injection pump 6, and the oil injection pipeline that penetrates the side wall of the vacuum tank 1 are coordinated to ensure that the oil injection operation can be carried out smoothly without disrupting the vacuum environment inside the vacuum tank 1. This ensures that the dried insulating material will not become damp due to contact with the outside air during the oil injection process, and significantly improves the insulation performance and overall quality of the product.

[0034] Example 4 Based on Embodiment 1, the oil-immersed inverted current transformer vacuum drying and oil injection device also includes a temperature control system. This system is configured to detect and adjust the temperature inside the vacuum tank 1 and the heating temperature of the drying system. Specifically, the temperature control system mainly consists of a temperature sensor, a temperature controller, and a heater. The temperature sensor is typically installed on the inner wall of the vacuum tank 1 or extends into the tank body to monitor the ambient temperature inside the vacuum tank 1 in real time. Simultaneously, a temperature sensor is also installed at the kerosene heating assembly 3 of the drying system. The temperature control system feeds back the detected temperature signal to the temperature controller and compares it with a preset process temperature curve. When the detected temperature is less than or equal to the set value, the temperature control system controls the heater to increase its power; when the detected temperature is higher than the set value, it reduces the power or stops heating. For kerosene vapor-phase drying, precise temperature control directly affects the saturation of kerosene vapor and the phase change heat release efficiency. Excessive temperature fluctuations may lead to uneven drying or damage to the insulation material. Precise adjustment by the temperature control system ensures that the temperature inside the vacuum tank is always maintained within the optimal process range, thereby guaranteeing consistent drying quality.

[0035] Furthermore, the device also includes a control unit, which is electrically connected to the drying system and the oil injection system, configured to control the coordinated operation of the drying system and the oil injection system. The control unit can be implemented in hardware such as a programmable logic controller (PLC), a microcontroller, or an industrial computer. The control unit is connected to the vacuum pump group 10, the kerosene heating assembly 3, the oil injection pump 6, various valves, and the temperature control system via signal cable 9. In actual operation, the control unit automatically executes each process step according to the preset program logic: first, it controls the vacuum pump group 10 to start until the preset vacuum level is reached; then, it starts the drying system for heating and drying, receiving feedback from the temperature control system in real time and adjusting the heating power accordingly; after drying, it automatically shuts down the drying system and starts the oil injection pump 6 for oil injection. This coordinated control not only achieves seamless connection between the subsystems, avoiding errors or timing mistakes that may occur during manual operation, but also enables the entire drying and oil injection process to achieve unattended automated operation, greatly improving production efficiency and process stability.

[0036] Example 5 This embodiment provides a method for drying and oiling an oil-immersed inverted current transformer using a vacuum drying and oiling device as described in any of the above embodiments. This method emphasizes the logical execution of timing steps, achieving an integrated drying and oiling process through the coordinated operation of the various systems within the device.

[0037] Specifically, the following steps are included: Step S100: Place the oil-immersed inverted current transformer 2 inside the vacuum tank 1. In this step, the operator opens the vacuum tank door 12 of the vacuum tank 1 and places the oil-immersed inverted current transformer 2 stably on the support frame inside the vacuum tank 1. The oil-immersed inverted current transformer 2 is usually placed upright, i.e., with its head facing down or in its normal working posture, to facilitate subsequent oil filling operations. While placing the oil-immersed inverted current transformer 2, the oil filling pipeline of the oil filling system needs to be pre-connected to the oil filling interface of the oil-immersed inverted current transformer 2 to ensure a good seal, preparing for subsequent oil filling in a vacuum environment.

[0038] Step S200: Vacuum tank 1 is evacuated. After closing and locking the vacuum tank door 12, the vacuum pump unit 10 is started to evacuate the inside of vacuum tank 1. The purpose of this step is to remove air and moisture from inside vacuum tank 1 and the surface of the oil-immersed inverted current transformer 2, creating the necessary vacuum environment for subsequent vapor-phase drying. The evacuation process usually continues until the vacuum level inside vacuum tank 1 reaches the preset process requirements to ensure that the drying medium vapor can smoothly enter and condense on the surface of the oil-immersed inverted current transformer 2.

[0039] Step S300: While maintaining a vacuum in vacuum tank 1, drying medium vapor is supplied to vacuum tank 1 via a drying system for drying treatment. This is one of the core steps of this embodiment. After the vacuum environment is established, the drying system is activated, supplying high-temperature drying medium vapor (such as kerosene vapor) to vacuum tank 1. Due to the negative pressure inside vacuum tank 1, the vapor can quickly diffuse and penetrate deep into the insulating material of the oil-immersed inverted current transformer 2. When the vapor comes into contact with the cooler surface of the oil-immersed inverted current transformer 2, a condensation phase change occurs, releasing a large amount of latent heat, thereby achieving rapid and uniform heating of the oil-immersed inverted current transformer 2 and removing moisture from the insulating material. During this process, vacuum tank 1 maintains a vacuum state throughout, eliminating the need to break the vacuum or transfer equipment midway as in traditional processes, ensuring the continuity and efficiency of the drying process.

[0040] Step S400: After the drying process is completed, while maintaining a vacuum in vacuum tank 1, an oil injection system is used to inject insulating oil into the oil-immersed inverted current transformer 2. This step, immediately following the drying step, is a key step demonstrating the technological advantages of this invention. When the drying process is complete and vacuum tank 1 is still under high vacuum, the oil injection system is directly activated, injecting insulating oil into the oil-immersed inverted current transformer 2 through pre-connected oil injection pipelines. Because the drying process and oil injection are performed sequentially within the same vacuum tank 1 and under the same vacuum environment, there is no vacuum breaking in between, thus completely eliminating the opportunity for the insulating material to come into contact with external humid air after drying and before oil injection, effectively preventing secondary moisture absorption of the insulating material. Simultaneously, the oil injection process under vacuum also helps to expel residual gas inside the oil-immersed inverted current transformer 2, improving the filling quality of the insulating oil.

[0041] In step S500, the pressure inside the vacuum tank 1 is released and the oil-immersed inverted current transformer 2 is removed. After the oil filling operation is completed and the insulating oil has fully permeated the tank, the pressure inside the vacuum tank 1 is slowly released through the pressure relief valve of the vacuum system to restore it to atmospheric pressure. Then, the vacuum tank door 12 is opened, the oil filling pipeline connection is disconnected, and the processed oil-immersed inverted current transformer 2 can be removed. At this point, the oil-immersed inverted current transformer 2 has completed a high-quality drying and oil filling process.

[0042] Through the above method, this embodiment achieves continuous drying and oiling operations within the same sealed vacuum environment. This optimized process not only significantly shortens the production cycle but, more importantly, eliminates the risk of insulation moisture damage caused by process transitions in traditional processes, thus significantly improving the electrical performance and reliability of the product.

[0043] Example 6 Based on Example 5, this example further optimizes the key parameters and process flow of the drying and oiling process. Specifically, after the drying process is completed, the oiling operation is performed directly while maintaining a vacuum state in the vacuum tank 1, and the vacuum level in the vacuum tank 1 remains continuous between the drying process and the oiling operation.

[0044] The core advantage of this process lies in its complete isolation from external moisture interference. At the end of the drying process, the insulating material of the oil-immersed inverted current transformer 2 is in a high-temperature and extremely dry state. At this time, the pores inside the insulating material are open, exhibiting a strong ability to absorb moisture. If a traditional process is used, the vacuum environment is disrupted and the equipment is moved after drying, causing the high-temperature insulating material to instantly absorb moisture from the air, resulting in a significant reduction in the drying effect, or even complete failure. This embodiment maintains the continuity of the vacuum level, allowing seamless switching between the drying and oiling processes in a completely sealed vacuum environment. The insulating material is coated or filled with insulating oil without contacting the outside air, thereby fundamentally eliminating the risk of secondary moisture absorption and ensuring that the insulation performance of the final product reaches its optimal level.

[0045] Furthermore, in this embodiment, the temperature range of the drying process is controlled between 120°C and 135°C. 120°C to 135°C is a preferred process window that balances drying efficiency and material safety.

[0046] The above description only illustrates embodiments of the present invention, but should not be construed as covering the entire scope of protection of the present invention. Equivalent changes or modifications, or proportional enlargements or reductions made by the paradigm based on the design spirit of the present invention should all be considered to fall within the protection scope of the present invention.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit its scope of protection. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that after reading the present invention, they can still make various changes, modifications or equivalent substitutions to the specific implementation of the invention, but these changes, modifications or equivalent substitutions are all within the scope of protection of the pending claims of the invention.

Claims

1. A vacuum drying and oil injection device for an oil-immersed inverted current transformer, characterized in that, include: Vacuum container (1) is used to house oil-immersed inverted current transformer (2). The drying system is connected to the vacuum tank (1) and is configured to deliver drying medium vapor into the vacuum tank (1), and to perform drying treatment by condensing the drying medium vapor on the surface of the oil-immersed inverted current transformer (2) and releasing heat through phase change. The oil injection system includes an oil injection pipeline that extends through the side wall of the vacuum tank (1) into the interior of the vacuum tank (1); The oil-immersed inverted current transformer vacuum drying and oil injection device is configured to perform drying and oil injection operations sequentially while maintaining a vacuum state inside the vacuum tank (1).

2. The vacuum drying and oil injection device for an oil-immersed inverted current transformer according to claim 1, characterized in that, The drying system is a kerosene vapor-phase drying system, configured to heat kerosene to generate kerosene vapor as the drying medium vapor.

3. The vacuum drying and oil injection device for an oil-immersed inverted current transformer according to claim 2, characterized in that, The kerosene vapor phase drying system includes: Kerosene heating assembly (3) is configured to heat kerosene to generate kerosene vapor; The condensation recovery component (4) is connected to the vacuum tank (1) and is configured to condense the kerosene vapor in the vacuum tank (1) into liquid kerosene and recycle it. The kerosene heating component (3) is connected to the vacuum tank (1) through a pipeline to deliver the generated kerosene vapor into the vacuum tank (1).

4. The vacuum drying and oil injection device for an oil-immersed inverted current transformer according to claim 1, characterized in that, The oil filling line is configured to extend into the vacuum tank (1) and connect to the oil filling port of the oil-immersed inverted current transformer (2).

5. The vacuum drying and oil injection device for an oil-immersed inverted current transformer according to claim 4, characterized in that, The oil injection system also includes: Oil storage tank (5) is used to store insulating oil; An oil pump (6) is installed on the oil injection pipeline and is configured to transport the insulating oil in the oil storage tank (5) to the inside of the oil-immersed inverted current transformer (2) through the oil injection pipeline. One end of the oil injection pipeline is connected to the oil storage tank (5), and the other end extends through the side wall of the vacuum tank (1) into the interior of the vacuum tank (1).

6. The vacuum drying and oil injection device for an oil-immersed inverted current transformer according to claim 1, characterized in that, It also includes a temperature control system (7) configured to detect and adjust the temperature inside the vacuum tank (1) and the heating temperature of the drying system.

7. The vacuum drying and oil injection device for an oil-immersed inverted current transformer according to claim 1, characterized in that, It also includes a control unit (8), which is electrically connected to the drying system and the oil injection system and is configured to control the drying system and the oil injection system to operate in coordination.

8. The method of using the vacuum drying and oil injection device for an oil-immersed inverted current transformer according to any one of claims 1-7, characterized in that, include: The oil-immersed inverted current transformer (2) is placed inside the vacuum tank (1); The vacuum container (1) is subjected to a vacuum process; While maintaining a vacuum inside the vacuum tank (1), a drying medium vapor is supplied to the vacuum tank (1) through a drying system for drying treatment; After the drying process is completed, the vacuum tank (1) is kept under vacuum and oil injection is performed by the oil injection system. The oil injection is to inject insulating oil into the oil-immersed inverted current transformer (2). Release the pressure inside the vacuum tank (1) and remove the oil-immersed inverted current transformer (2).

9. The method of using the vacuum drying and oil injection device for an oil-immersed inverted current transformer according to claim 8, characterized in that, After the drying process is completed, the oil injection operation is carried out directly in the vacuum tank (1) while maintaining a vacuum state. The vacuum degree in the vacuum tank (1) is maintained continuously between the drying process and the oil injection operation.

10. The method of using the vacuum drying and oil injection device for an oil-immersed inverted current transformer according to claim 8, characterized in that, The drying process is performed at a temperature range of 120°C to 135°C.

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