A stage sealing moisture absorber for oil-immersed transformer

Abstract

The utility model relates to a kind of stage sealing moisture absorber for oil-immersed transformer, including: moisture absorber body, including glass cylinder, protective net and moisture absorbent, protective net is set in the inner bottom of glass cylinder, and moisture absorbent is filled in glass cylinder;Upper cover, including upper flange and material mouth cover;Lower cover, including protective cover stud, lower flange, exhaust valve, air inlet valve, exhaust valve spring, air inlet valve spring, first spring support and second spring support;The top of protective cover stud is connected with protective net, and protective cover stud is set between exhaust valve and air inlet valve.The utility model can make transformer under certain internal pressure, isolated from outside atmosphere, and pressure can be adjusted;Reduce the transformation of transformer and atmosphere, extend the replacement cycle of replacement moisture absorbent;Make field operation and maintenance personnel no longer need irregular maintenance;Product can be placed for a long time without failure.

Description

Technical Field

[0001] This utility model relates to the field of dehumidifier technology, and more specifically, to a stage-sealed dehumidifier for oil-immersed transformers. Background Technology

[0002] Oil-immersed transformers contain a large amount of transformer oil, which serves to enhance insulation performance and cool the transformer. The volume of transformer oil changes with temperature; it expands as the temperature rises and contracts as the temperature falls. Therefore, during actual operation, the volume of transformer oil in an oil-immersed transformer changes due to ambient temperature or load. To balance the internal pressure changes caused by these volume changes, oil-immersed transformers use an oil conservator (an auxiliary oil tank) to store the transformer oil that increases in volume due to temperature increases or to replenish the oil that decreases due to temperature decreases. The conservator is mostly filled with transformer oil and a small amount of air. When the oil level rises due to volume expansion, the air is expelled from the conservator and enters the atmosphere; when the oil level falls due to volume contraction, air enters the conservator from the atmosphere, thus balancing the internal pressure of the transformer and preventing damage from excessive pressure or vacuum. During the process of air entering and exiting the transformer's oil conservator, moisture from the air also enters the conservator. If temperature changes occur, this moisture will condense inside the transformer, affecting its insulation performance. To solve this problem, a desiccant is added to the transformer's breathing line during use to absorb the moisture that enters the transformer. This is the desiccant for oil-immersed transformers.

[0003] The technological development of desiccant for oil-immersed transformers has evolved from simple to complex, and from passive to active. Early desiccant-based desiccants primarily used desiccants and other drying materials to absorb moisture from transformer oil through physical adsorption. These desiccant-based desiccants were simple in structure but suffered from drawbacks such as frequent replacement, high maintenance costs, and limited adsorption capacity. With technological advancements, desiccant-based desiccants with indicator functions emerged, using visual methods such as color changes to indicate the saturation level of the desiccant to maintenance personnel, thereby improving the safety and reliability of transformer operation. Furthermore, to improve desiccation efficiency and extend service life, some new desiccant-based desiccants have begun to use molecular sieve materials, which have stronger adsorption capacity and better selectivity, enabling more effective moisture removal. However, regardless of the desiccant used or the desiccant structure, it is impossible to completely absorb moisture from the air. This means that moisture from the air can still enter the transformer, still affecting its performance.

[0004] See Figure 1Existing desiccant for oil-immersed transformers has a simple structure. Its main body is a cavity filled with desiccant. One end of the cavity is connected to the transformer's oil conservator via a pipe, and the other end passes through an oil cup. The transformer oil in the oil cup is isolated from the atmosphere. When there is a pressure change, gas enters or exits the transformer's oil conservator through the oil cup. This structure has the following disadvantages: whenever there is a pressure change inside the transformer, gas will enter or exit the transformer; regular and irregular maintenance is required at the site to ensure that the transformer oil in the oil cup covers the gas outlet of the pipe; long-term storage without use can cause the desiccant to absorb moisture and change color, eventually leading to failure.

[0005] Therefore, there is an urgent need for a stage-sealed desiccant for oil-immersed transformers to solve the problem that moisture in the air can still enter the transformer in the existing technology. Utility Model Content

[0006] In view of this, this utility model proposes a stage-sealed desiccant for oil-immersed transformers, aiming to solve the problem that moisture in the air can still enter the transformer in the prior art.

[0007] This utility model provides a staged sealing desiccant for oil-immersed transformers, comprising:

[0008] The desiccant body includes a glass tube, a protective net, and a desiccant. The protective net is located at the bottom inside the glass tube, the desiccant is filled inside the glass tube, and the desiccant is also located at the top of the protective net.

[0009] The top cover includes an upper flange and a material inlet cover. The upper flange is connected to the top of the glass cylinder. The upper flange is used to connect the breather pipe of the transformer's oil conservator. The material inlet cover is located on the top of the upper flange.

[0010] The lower cover includes a protective cover stud, a lower flange, an exhaust valve, an intake valve, an exhaust valve spring, an intake valve spring, a first spring support, and a second spring support. The top of the protective cover stud is connected to the protective mesh. The protective cover stud is positioned between the exhaust valve and the intake valve. The lower flange has two through holes. The exhaust valve is connected to the lower flange through one of the through holes, and the intake valve is connected to the lower flange through the other through hole. The exhaust valve spring is pressed against the lower flange by the first spring support, and the intake valve spring is pressed against the lower flange by the second spring support.

[0011] Furthermore, the upper cover also includes:

[0012] The mounting stud comprises a first hexagonal nut, a first spring washer, and a flat washer. One end of the mounting stud passes through the upper flange, and the other end passes through the lower flange. The first hexagonal nut is mounted on the mounting stud. The first spring washer and the flat washer are sequentially mounted on the mounting stud from the first hexagonal nut towards the upper flange and from the first hexagonal nut towards the lower flange. The mounting stud and the first hexagonal nut are combined to fix the upper flange, the glass cylinder, and the lower flange.

[0013] Furthermore, the upper cover also includes:

[0014] A rubber ring for the feed inlet is disposed between the feed inlet cover and the upper flange.

[0015] Furthermore, the bottom of the upper cover is provided with a rubber ring groove, and the upper part of the lower cover is also provided with a rubber ring groove. A glass tube rubber ring is provided in the rubber ring groove, and the glass tube rubber ring is also located between the glass tube and the upper cover, and between the glass tube and the lower cover.

[0016] Furthermore, the lower cover also includes:

[0017] A second hexagonal nut and a second spring washer are fitted onto the protective cover stud, and the second hexagonal nut is fitted onto the protective cover stud, with the second hexagonal nut located above the second spring washer.

[0018] Furthermore, the exhaust valve is provided with a rubber ring groove, and an exhaust valve rubber ring is installed in the rubber ring groove of the exhaust valve.

[0019] The intake valve is provided with a rubber ring groove, and an intake valve rubber ring is installed in the rubber ring groove of the intake valve.

[0020] Furthermore, the lower cover also includes:

[0021] A third hexagonal nut and a third spring washer are provided. The third hexagonal nut is located on the exhaust valve and is also located above the first spring support. The third spring washer is located between the first spring support and the third hexagonal nut.

[0022] Furthermore, the lower cover also includes a fourth hexagonal nut and a fourth spring washer. The fourth hexagonal nut is disposed on the intake valve and is also located below the second spring support. The fourth spring washer is disposed between the second spring support and the fourth hexagonal nut.

[0023] Compared with existing technologies, the beneficial effects of this utility model are as follows: This utility model can isolate the transformer from the external atmosphere under a certain internal pressure, and the pressure is adjustable; it reduces the exchange between the transformer and the atmosphere, extending the replacement cycle of the desiccant; it eliminates the need for on-site maintenance personnel to perform irregular maintenance; and it allows the product to be stored for a long time without failure. Specifically, through the design of the protective cover studs, lower flange, exhaust valve, inlet valve, exhaust valve spring, inlet valve spring, first spring support, and second spring support of the lower cover, the valves are tightly sealed under the action of the exhaust valve spring and inlet valve spring, isolating the transformer from the atmosphere when the pressure does not reach the set threshold; adjusting the hexagonal nut changes the spring compression, achieving adjustable pressure, which reduces the amount of air exchange between the transformer and the atmosphere, reduces moisture entry, and extends the replacement cycle of the desiccant; the oil cup structure is eliminated, avoiding irregular maintenance caused by oil cup maintenance and frequent desiccant replacement; when not in use, the valve is sealed, preventing external air from contacting the desiccant and ensuring that the product remains effective even after long-term storage. Attached Figure Description

[0024] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0025] Figure 1 This is a schematic diagram of the structure of a desiccant for an oil-immersed transformer in the prior art.

[0026] Figure 2 A schematic diagram of the structure of a stage-sealed moisture absorber for an oil-immersed transformer provided in an embodiment of this utility model;

[0027] Figure 3 A cross-sectional view of a staged sealing moisture absorber for an oil-immersed transformer provided in an embodiment of this utility model;

[0028] Figure 4 A schematic diagram of the exhaust process of the stage-sealed moisture absorber for an oil-immersed transformer provided in an embodiment of this utility model;

[0029] Figure 5 This is a schematic diagram of the air intake of the stage-sealed desiccant for an oil-immersed transformer provided in an embodiment of this utility model.

[0030] In the diagram: 1. Upper flange; 2. Inlet cover; 3. Inlet rubber ring; 4. Mounting stud; 5. First hexagonal nut; 6. First spring washer; 7. Flat washer; 8. Glass tube rubber ring; 9. Glass tube; 10. Protective cover stud; 11. Second hexagonal nut; 12. Second spring washer; 13. Protective net; 14. Third hexagonal nut; 15. Third spring washer; 16. First spring support; 17. Exhaust valve spring; 18. Exhaust valve rubber ring; 19. Lower flange; 20. Exhaust valve; 21. Fourth hexagonal nut; 22. Fourth spring washer; 23. Second spring support; 24. Inlet valve spring; 25. Inlet valve rubber ring; 26. Inlet valve; 27. Desiccant. Detailed Implementation

[0031] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0032] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", 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.

[0033] 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 technical features indicated. Therefore, a feature defined as "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.

[0034] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" 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 mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0035] See Figure 1Existing desiccant for oil-immersed transformers has a simple structure. Its main body is a cavity filled with desiccant. One end of the cavity is connected to the transformer's oil conservator via a pipe, and the other end passes through an oil cup. The transformer oil in the oil cup is isolated from the atmosphere. When there is a pressure change, gas enters or exits the transformer's oil conservator through the oil cup. This structure has the following disadvantages: whenever there is a pressure change inside the transformer, gas will enter or exit the transformer; regular and irregular maintenance is required at the site to ensure that the transformer oil in the oil cup covers the gas outlet of the pipe; long-term storage without use can cause the desiccant to absorb moisture and change color, eventually leading to failure.

[0036] Therefore, there is an urgent need for a stage-sealed desiccant for oil-immersed transformers to solve the problem that moisture in the air can still enter the transformer in the existing technology.

[0037] See Figure 2-5 As shown, this embodiment provides a staged sealing desiccant for oil-immersed transformers, including a desiccant body, a glass cylinder 9, a protective net 13, and a desiccant 27. The protective net 13 is disposed at the bottom of the inner side of the glass cylinder 9, and the desiccant 27 is filled in the glass cylinder 9. The desiccant 27 is also located above the protective net 13.

[0038] The top cover includes an upper flange 1 and a material inlet cover 2. The upper flange 1 is connected to the top of the glass cylinder 9. The upper flange 1 is used to connect the oil conservator breather pipe of the transformer. The material inlet cover 2 is located on the top of the upper flange 1.

[0039] The lower cover includes a protective cover stud 10, a lower flange 19, an exhaust valve 20, an intake valve 26, an exhaust valve spring 17, an intake valve spring 24, a first spring support 16, and a second spring support 23. The top of the protective cover stud 10 is connected to the protective net 13. The protective cover stud 10 is located between the exhaust valve 20 and the intake valve 26. The lower flange 19 has two through holes. The exhaust valve 20 is connected to the lower flange 19 through one of the through holes, and the intake valve 26 is connected to the lower flange 19 through the other through hole. The exhaust valve spring 17 is pressed onto the lower flange 19 through the first spring support 16, and the intake valve spring 24 is pressed onto the lower flange 19 through the second spring support 23.

[0040] It is understood that this utility model can isolate the transformer from the outside atmosphere under a certain internal pressure, and the pressure is adjustable; it reduces the exchange between the transformer and the atmosphere, extends the replacement cycle of the desiccant 27; eliminates the need for on-site maintenance personnel to perform irregular maintenance; and allows the product to be stored for a long time without failure. Specifically, through the design of the protective cover stud 10, lower flange 19, exhaust valve 20, intake valve 26, exhaust valve spring 17, intake valve spring 24, first spring support 16 and second spring support 23, the valves are tightly sealed under the action of the exhaust valve spring 17 and intake valve spring 24, isolating the transformer from the atmosphere when the pressure does not reach the set threshold; adjusting the hexagonal nut changes the spring compression, achieving adjustable pressure, which reduces the amount of air exchange between the transformer and the atmosphere, reduces moisture entry, and extends the replacement cycle of the desiccant 27; the oil cup structure is eliminated, avoiding irregular maintenance caused by oil cup maintenance and frequent replacement of the desiccant 27; when not in use, the valve is sealed to prevent outside air from contacting the desiccant 27, ensuring that the product can be stored for a long time without failure.

[0041] In some embodiments of this application, the top cover further includes:

[0042] Mounting stud 4, first hexagonal nut 5, first spring washer 6, and flat washer 7 are installed. One end of mounting stud 4 passes through the upper flange 1, and the other end of mounting stud 4 passes through the lower flange 19. The first hexagonal nut 5 is set on the mounting stud 4. The first spring washer 6 and flat washer 7 are set on the mounting stud 4 in sequence from the first hexagonal nut 5 to the upper flange 1 and from the first hexagonal nut 5 to the lower flange 19. The mounting stud 4 and the first hexagonal nut 5 are combined to fix the upper flange 1, the glass cylinder 9, and the lower flange 19.

[0043] In some embodiments of this application, the top cover further includes:

[0044] The feed inlet rubber ring 3 is located between the feed inlet cover 2 and the upper flange 1.

[0045] In some embodiments of this application, a rubber ring groove is provided at the bottom of the upper cover and a rubber ring groove is also provided at the top of the lower cover. A glass tube rubber ring 8 is provided in the rubber ring groove. The glass tube rubber ring 8 is also located between the glass tube 9 and the upper cover, and between the glass tube 9 and the lower cover.

[0046] In some embodiments of this application, the lower cover further includes:

[0047] The second hexagonal nut 11 and the second spring washer 12 are fitted onto the protective cover stud 10, and the second hexagonal nut 11 is fitted onto the protective cover stud 10, with the second hexagonal nut 11 located above the second spring washer 12.

[0048] In some embodiments of this application, an exhaust valve 20 is provided with a rubber ring groove, and an exhaust valve rubber ring 18 is installed in the rubber ring groove of the exhaust valve 20.

[0049] The intake valve 26 is provided with a rubber ring groove, and the intake valve rubber ring 25 is installed in the rubber ring groove of the intake valve 26.

[0050] In some embodiments of this application, the lower cover further includes:

[0051] The third hexagonal nut 14 and the third spring washer 15 are located on the exhaust valve 20. The third hexagonal nut 14 is also located on the upper part of the first spring support 16. The third spring washer 15 is located between the first spring support 16 and the third hexagonal nut 14.

[0052] In some embodiments of this application, the lower cover further includes: a fourth hexagonal nut 21 and a fourth spring washer 22. The fourth hexagonal nut 21 is disposed on the intake valve 26 and is also located at the lower part of the second spring support 23. The fourth spring washer 22 is disposed between the second spring support 23 and the fourth hexagonal nut 21.

[0053] The working principle of this utility model is as follows: When the internal pressure of the transformer increases due to the rise in oil temperature, the transformer oil flows to the oil conservator. The air in the oil conservator is squeezed into the stage sealing desiccant through the breathing pipe. If the internal pressure of the transformer is less than the set pressure threshold of the stage sealing desiccant, the exhaust valve 20 of the stage sealing desiccant is tightly connected to the lower flange 19, reliably sealing and blocking the exchange of air between the transformer and the atmosphere. If the pressure continues to rise, and the internal pressure of the transformer exceeds the set threshold of the stage sealing desiccant, the exhaust valve 20, along with the exhaust valve rubber ring 18, disengages from the lower flange 19 to release air, thereby reducing the internal pressure of the transformer. After the pressure is released, when the internal pressure of the transformer is lower than the set threshold of the stage sealing desiccant, the exhaust valve, along with the exhaust valve rubber ring 18, tightly adheres to the sealing surface of the lower flange 19, resealing the transformer. Under the premise of ensuring that the internal pressure of the transformer is not destructive, the amount of air exchange between the transformer and the atmosphere is reduced, extending the service life of the desiccant 27. When the internal pressure of the transformer decreases due to the drop in oil temperature, the transformer oil flows from the conservator to the oil tank, increasing the cavity inside the conservator and creating a vacuum. This causes the air inside the conservator to be drawn into the stage sealing desiccant through the breathing pipe. If the vacuum level inside the transformer is lower than the set pressure threshold of the stage sealing desiccant, the air inlet valve 26 of the stage sealing desiccant, along with the air inlet valve rubber ring 25, is tightly connected to the lower flange 19, reliably sealing and preventing the exchange of air between the transformer and the atmosphere. If the vacuum level inside the transformer continues to rise, exceeding the set threshold of the stage sealing desiccant, the air inlet valve 26, along with the air inlet valve rubber ring 25, disengages from the sealing surface of the lower flange 19, drawing in air to reduce the internal vacuum level. When the vacuum level drops below the set threshold of the stage sealing desiccant, the air inlet valve 26, along with the air inlet valve rubber ring 25, re-closes tightly to the sealing surface of the lower flange 19. This reduces the amount of air exchange between the transformer and the atmosphere while ensuring that the internal pressure of the transformer is not damaged, thus extending the service life of the desiccant 27.

[0054] It will be understood by those skilled in the art that the above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A stage-sealed desiccant for oil-immersed transformers, characterized in that, include: The desiccant body includes a glass tube, a protective net, and a desiccant. The protective net is located at the bottom inside the glass tube, the desiccant is filled inside the glass tube, and the desiccant is also located at the top of the protective net. The top cover includes an upper flange and a material inlet cover. The upper flange is connected to the top of the glass cylinder. The upper flange is used to connect the breather pipe of the transformer's oil conservator. The material inlet cover is located on the top of the upper flange. The lower cover includes a protective cover stud, a lower flange, an exhaust valve, an intake valve, an exhaust valve spring, an intake valve spring, a first spring support, and a second spring support. The top of the protective cover stud is connected to the protective mesh. The protective cover stud is positioned between the exhaust valve and the intake valve. The lower flange has two through holes. The exhaust valve is connected to the lower flange through one of the through holes, and the intake valve is connected to the lower flange through the other through hole. The exhaust valve spring is pressed against the lower flange by the first spring support, and the intake valve spring is pressed against the lower flange by the second spring support.

2. The stage-sealed desiccant for oil-immersed transformers according to claim 1, characterized in that, The top cover also includes: The mounting stud comprises a first hexagonal nut, a first spring washer, and a flat washer. One end of the mounting stud passes through the upper flange, and the other end passes through the lower flange. The first hexagonal nut is mounted on the mounting stud. The first spring washer and the flat washer are sequentially mounted on the mounting stud from the first hexagonal nut towards the upper flange and from the first hexagonal nut towards the lower flange. The mounting stud and the first hexagonal nut are combined to fix the upper flange, the glass cylinder, and the lower flange.

3. The stage-sealed desiccant for oil-immersed transformers according to claim 1, characterized in that, The top cover also includes: A rubber ring for the feed inlet is disposed between the feed inlet cover and the upper flange.

4. The staged sealing desiccant for oil-immersed transformers according to claim 1, characterized in that, The bottom of the upper cover is provided with a rubber ring groove, and the upper part of the lower cover is also provided with a rubber ring groove. A glass tube rubber ring is provided in the rubber ring groove. The glass tube rubber ring is also located between the glass tube and the upper cover, and between the glass tube and the lower cover.

5. The staged sealing desiccant for oil-immersed transformers according to claim 1, characterized in that, The lower cover also includes: A second hexagonal nut and a second spring washer are fitted onto the protective cover stud, and the second hexagonal nut is fitted onto the protective cover stud, with the second hexagonal nut located above the second spring washer.

6. The staged sealing desiccant for oil-immersed transformers according to claim 1, characterized in that, The exhaust valve is provided with a rubber ring groove, and an exhaust valve rubber ring is installed in the rubber ring groove of the exhaust valve. The intake valve is provided with a rubber ring groove, and an intake valve rubber ring is installed in the rubber ring groove of the intake valve.

7. The staged sealing desiccant for oil-immersed transformers according to claim 1, characterized in that, The lower cover also includes: A third hexagonal nut and a third spring washer are provided. The third hexagonal nut is located on the exhaust valve and is also located above the first spring support. The third spring washer is located between the first spring support and the third hexagonal nut.

8. The staged sealing desiccant for oil-immersed transformers according to claim 1, characterized in that, The lower cover also includes: The fourth hexagonal nut and the fourth spring washer are provided. The fourth hexagonal nut is located on the intake valve and is also located below the second spring support. The fourth spring washer is located between the second spring support and the fourth hexagonal nut.

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