An open-type oil-immersed transformer

Abstract

The present application relates to the technical field of transformer, and particularly discloses an open oil-immersed transformer, which comprises an oil tank, an oil pillow in communication with the oil tank, a transformer body arranged in the oil tank, and a compensation assembly arranged in the oil pillow, and the oil pillow has an air cavity above the insulating oil. The compensation assembly comprises a mounting pipeline and a floating sealing element, the floating sealing element is slidingly arranged in the mounting pipeline and rises and falls with the volume change of the insulating oil, the mounting pipeline is provided with a containing groove filled with granular desiccant, the containing groove has an inlet and an outlet, and the floating sealing element is provided with a diaphragm. When the floating sealing element is at the lower limit position, the diaphragm is concave and the desiccant falls to the edge of the diaphragm to form a moisture absorption layer; when the floating sealing element is at the upper limit position, the diaphragm is convex and the desiccant returns to the containing groove. The structure can adsorb and isolate the moisture between the air cavity and the insulating oil during the oil level compensation process, reduces the moisture absorption and oxidation speed of the insulating oil, and prolongs the service life.

Description

Technical Field

[0001] This invention relates to the field of transformer technology, and specifically to an open-type oil-immersed transformer. Background Technology

[0002] Oil-immersed transformers are commonly used electrical equipment in power transmission and distribution systems. They typically consist of an oil tank, an iron core and windings housed within the tank, and insulating oil filling the tank. The insulating oil serves multiple functions, including insulation, heat dissipation, and arc extinguishing. For open-type oil-immersed transformers with an oil conservator, the conservator compensates for volume changes in the insulating oil due to temperature variations. An air space is usually maintained above the insulating oil within the conservator, and pressure is balanced with the external environment through a breathing structure. When the insulating oil expands due to load changes or ambient temperature variations, air is expelled from the conservator; when the insulating oil contracts, outside air enters the conservator, preventing the tank and conservator from experiencing excessive positive or negative pressure.

[0003] Chinese patent application CN202410513084.2 discloses an oil-immersed transformer insulating oil replacement device, which includes an oil pump, filter, valves, and pipelines. It can extract insulating oil from the transformer and introduce new or purified insulating oil, thereby achieving the replacement, filtration, and maintenance of the insulating oil. This type of technical solution is mainly aimed at the maintenance treatment of insulating oil that has deteriorated or become contaminated. By improving the oil quality through external replacement and purification equipment, it can restore the insulating and heat dissipation properties of the insulating oil to a certain extent.

[0004] However, in the long-term operation of open-type oil-immersed transformers, the deterioration of insulating oil is not only due to post-operation contamination, but also related to the continuous entry of outside air during the oil conservator's "breathing" process. Outside air contains moisture and oxygen; when humid air enters the oil conservator, it easily comes into contact with the insulating oil, causing it to gradually absorb moisture and oxidize. This leads to increased dielectric loss, decreased breakdown voltage, and accelerated insulation aging. While replacing or purifying the insulating oil only after it has deteriorated can improve its quality, the maintenance cost is high, and the downtime or maintenance cycle is also affected. Therefore, a structure is needed that can adapt to the oil level compensation process of open-type oil-immersed transformers and reduce the probability of humid air contacting the insulating oil inside the oil conservator, thereby slowing down the rate of moisture absorption and oxidation of the insulating oil and extending its service life. Summary of the Invention

[0005] This invention provides an open-type oil-immersed transformer, which aims to solve the problem in related technologies that external humid air can easily enter and contact the insulating oil during the oil conservator's breathing process, leading to moisture absorption, oxidation of the insulating oil and increased maintenance costs.

[0006] An open-type oil-immersed transformer includes an oil tank, an oil conservator connected to the oil tank, and a transformer body disposed within the oil tank. The oil conservator has an air cavity above the insulating oil. A compensation assembly is disposed within the oil conservator, comprising an installation pipe and a floating seal. The floating seal is slidably disposed on the installation pipe and rises and falls with the volume change of the insulating oil to isolate the insulating oil from the air cavity. The installation pipe has a receiving groove filled with granular desiccant, and the receiving groove has an inlet and an outlet. A diaphragm is disposed on the floating seal. When the floating seal is at its lower limit, the diaphragm indents due to the pressure difference, and its edge is lower than the outlet, allowing the desiccant to fall onto the diaphragm and form a moisture-absorbing layer between the edge of the diaphragm and the installation pipe. When the floating seal is at its upper limit, the diaphragm bulges due to the pressure difference, and its edge aligns with the inlet, allowing the desiccant to enter the receiving groove. The effect is that the floating seal within the oil conservator can rise and fall synchronously with the oil level changes caused by the thermal expansion and contraction of the insulating oil, forming a dynamic isolation structure between the insulating oil surface and the air cavity, reducing the area of ​​direct contact between the gas in the air cavity and the insulating oil. As the insulating oil volume decreases and the floating seal descends to its lower limit, the pressure inside the air cavity continues to decrease. Under the pressure difference, the diaphragm indents, allowing the granular desiccant in the receiving tank to fall from the outlet to the edge of the diaphragm, forming a moisture-absorbing layer between the diaphragm edge and the installation pipe. This moisture-absorbing layer, located in the inner gap of the floating seal, can absorb moisture that may enter the insulating oil side through the periphery of the installation pipe. When the insulating oil volume increases, the floating seal rises to its upper limit, and the diaphragm bulges under the pressure difference, causing the desiccant to re-enter the receiving tank. This oil level compensation process achieves the placement and recovery of the desiccant without the need for a complex additional drive mechanism. It maintains the pressure compensation capability of the open-type oil-immersed transformer while slowing down the moisture absorption and oxidation rate of the insulating oil, reducing the frequency of subsequent oil changes and maintenance.

[0007] Preferably, the receiving tank is arranged in a ring shape, with both the inlet and outlet extending circumferentially along the installation pipe to form a ring. The advantage of this is that the ring-shaped receiving tank allows for continuous arrangement of desiccant around the installation pipe, ensuring uniform distribution and recovery of the desiccant along the circumference of the floating seal, thus avoiding uneven circumferential sealing and moisture-proofing effects caused by the formation of only localized moisture-absorbing areas.

[0008] Preferably, a heating device is installed in the receiving tank to heat and regenerate the desiccant entering the receiving tank. The effect is that the desiccant, after returning to the receiving tank, can be heated by the heating device, causing the desiccant that has absorbed moisture to desorb and regenerate, improving the desiccant's reusability and reducing the frequency of manual desiccant replacement.

[0009] Preferably, the heating device includes an annular heating element disposed inside the receiving tank, the annular heating element extending circumferentially along the receiving tank. The advantage is that the annular heating element is adapted to the shape of the annular receiving tank, enabling more uniform heating of the desiccant circumferentially, reducing problems such as insufficient local desiccant regeneration or excessively high local temperatures.

[0010] Preferably, a baffle ring is provided on the diaphragm to prevent the desiccant from moving towards the center of the diaphragm. The effect is that the baffle ring limits the movement range of the desiccant on the diaphragm, causing the desiccant to mainly remain in the edge area of ​​the diaphragm, thereby forming a moisture-absorbing layer between the edge of the diaphragm and the installation pipe, reducing the impact of desiccant accumulation in the center of the diaphragm on diaphragm deformation.

[0011] Preferably, a guide ramp is provided at the inlet to guide the desiccant on the diaphragm into the receiving tank. The effect is that when the diaphragm protrudes and aligns with the inlet, the guide ramp can smoothly guide the desiccant into the receiving tank, reducing the possibility of desiccant remaining at the inlet or insufficient recovery.

[0012] Preferably, the outlet is positioned towards the edge of the diaphragm to allow the desiccant to fall between the outer side of the baffle ring and the edge of the diaphragm. This has the advantage that the outlet can directly guide the desiccant to the location where the moisture-absorbing layer needs to be formed, resulting in a shorter desiccant drop path, more accurate drop location, and, together with the baffle ring, limiting the desiccant accumulation area.

[0013] Preferably, a drying chamber is installed on the oil conservator, and the drying chamber is filled with desiccant. The drying chamber is connected to the air cavity. The effect is that the outside air can be pre-dried in the drying chamber before entering the air cavity, reducing the moisture content of the air entering the air cavity and further reducing the possibility of moisture diffusing to the insulating oil side.

[0014] Preferably, an exhaust pipe is provided on the oil conservator, and the bottom of the exhaust pipe is connected to the air chamber through an exhaust one-way valve. The exhaust one-way valve only allows gas in the air chamber to be discharged outward through the exhaust pipe. An intake one-way valve is provided at the connection between the drying chamber and the air chamber, allowing outside air to enter the air chamber only through the drying chamber. The effect is that air intake and exhaust are carried out through different one-way channels. When the air chamber is under negative pressure, outside air can only enter through the drying chamber, and when the air chamber is under positive pressure, the internal gas can only be discharged through the exhaust pipe, avoiding mutual interference between the intake and exhaust paths.

[0015] Preferably, the middle of the receiving tank is connected to an exhaust chamber, the annular heating element is located below the exhaust chamber, and a filter screen is provided between the receiving tank and the exhaust chamber to prevent the desiccant from passing through. The exhaust chamber is connected to a connecting channel that connects to an air chamber. The effect is that the moisture generated during the heating and regeneration of the desiccant can enter the exhaust chamber through the filter screen, then enter the air chamber through the connecting channel, and be discharged with the gas when the air chamber is vented; the filter screen can prevent particulate desiccant from entering the exhaust chamber and the connecting channel, ensuring that the desiccant remains in the receiving tank for recycling.

[0016] The beneficial effects of the present invention using the above technical solution are as follows: The present invention, by setting a floating seal within the oil conservator that can rise and fall with changes in the volume of the insulating oil, continuously isolates the insulating oil from the air cavity during oil level compensation. Simultaneously, utilizing the pressure difference deformation of the diaphragm after its upper and lower limits, the granular desiccant forms a moisture-absorbing layer at the edge of the diaphragm and returns to the receiving tank when the oil level recovers, thus achieving automatic arrangement, moisture absorption, and recovery of the desiccant. Through the cooperation of the heating device, drying chamber, inlet one-way valve, and exhaust one-way valve, the recovered desiccant can also be regenerated, and the air entering the air cavity is first dried, thereby reducing the degree to which the insulating oil is affected by humid air. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0018] Figure 2 This is a cross-sectional view of the oil pillow and compensation component in the moisture-absorbing layer formation state of the present invention.

[0019] Figure 3 for Figure 2 A magnified schematic diagram of the structure at point A in the middle.

[0020] Figure 4 This is a cross-sectional view of the oil reservoir in the desiccant recovery state of the present invention.

[0021] Figure 5 This is a schematic diagram of the diaphragm in the recessed state in this invention.

[0022] Figure 6 This is a schematic diagram of the diaphragm in the bulging state in this invention.

[0023] Figure label: 1. Oil tank; 2. Oil conservator; 21. Air chamber; 3. Compensation assembly; 31. Installation pipe; 311. Receiving tank; 312. Inlet; 313. Outlet; 314. Guide slope; 315. Exhaust chamber; 316. Filter screen; 317. Connecting channel; 32. Floating seal; 33. Desiccant; 34. Diaphragm; 35. Moisture-absorbing layer; 36. Annular heating element; 37. Material retaining ring; 4. Drying box; 41. Inlet check valve; 5. Exhaust pipe; 51. Exhaust check valve; 6. Insulating oil. Detailed Implementation

[0024] Embodiments of the present invention are described in detail below, with examples of the embodiments illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0025] like Figures 1 to 6As shown, the system includes an oil tank 1, an oil conservator 2, a transformer body, and a compensation assembly 3. The oil conservator 2 is positioned above and connected to the oil tank 1, the transformer body is located inside the oil tank 1, and the compensation assembly 3 is located inside the oil conservator 2. The oil tank 1 is filled with insulating oil 6, and the oil conservator 2 contains insulating oil 6 and an air cavity 21 located above the insulating oil 6. The air cavity 21 provides pressure compensation space when the volume of the insulating oil 6 changes. The oil conservator 2 is equipped with an oil injection structure for replenishing insulating oil 6 into the oil tank 1 or the oil conservator 2. The oil conservator 2 is also equipped with a safety pressure balancing structure, which includes a safety venting channel and a safety air replenishment channel. The safety venting channel is used to expel gas from the air cavity 21 when the pressure in the air cavity 21 rises abnormally, and the safety air replenishment channel is used to replenish air into the air cavity 21 when the pressure in the air cavity 21 drops abnormally.

[0026] The oil tank 1 is used to contain the transformer body and insulating oil 6. The transformer body includes the iron core and windings. The insulating oil 6 covers the outside of the transformer body and is used for insulation and heat dissipation. After the oil conservator 2 is connected to the oil tank 1, the insulating oil 6 in the oil tank 1 can enter the oil conservator 2 when the temperature rises and expands. When the insulating oil 6 in the oil tank 1 contracts when the temperature drops, the insulating oil 6 in the oil conservator 2 can flow back to the oil tank 1, so that the liquid level and internal pressure of the insulating oil 6 in the oil tank 1 are maintained within the allowable range.

[0027] The compensation component 3 includes an installation conduit 31 and a floating seal 32. The installation conduit 31 is vertically disposed within the oil conservator 2, and its interior or periphery can form a ventilation space associated with the air cavity 21. The floating seal 32 is slidably disposed on the installation conduit 31 and rises and falls within the oil conservator 2 as the volume of the insulating oil 6 changes. The floating seal 32 can cover the oil surface of the insulating oil 6, thereby isolating the insulating oil 6 from the air cavity 21 and reducing direct contact between air in the air cavity 21 and the insulating oil 6.

[0028] The installation pipe 31 is provided with a receiving tank 311, which is filled with granular desiccant 33. The receiving tank 311 has an inlet 312 and an outlet 313. The desiccant 33 can be silica gel desiccant 33, molecular sieve desiccant 33, or other granular moisture-absorbing materials that can absorb moisture and are regenerable. The receiving tank 311 is used for temporary storage of the desiccant 33, the outlet 313 is used to release the desiccant 33 onto the diaphragm 34 when it is necessary to form a moisture-absorbing layer 35, and the inlet 312 is used to recover the desiccant 33 on the diaphragm 34 after the floating seal 32 rises.

[0029] A diaphragm 34 is provided on the floating seal 32. The diaphragm 34 is a flexible membrane capable of elastic deformation, and its edge area can be concave or convex depending on the pressure difference between the air cavity 21 and the lower side of the floating seal 32. When the floating seal 32 is in the lower limit position, if the volume of the insulating oil 6 continues to shrink, the pressure in the air cavity 21 decreases accordingly. Under the action of the pressure difference, the diaphragm 34 is concave, and the edge of the diaphragm 34 drops to a position below the outlet 313, allowing the desiccant 33 in the receiving tank 311 to fall onto the diaphragm 34 through the outlet 313, and accumulate between the edge of the diaphragm 34 and the mounting pipe 31 to form a moisture-absorbing layer 35. The moisture-absorbing layer 35 is located on the side of the mounting pipe 31 where gas may enter the insulating oil 6, and can adsorb moisture in that area.

[0030] When the floating seal 32 is at its upper limit, if the volume of the insulating oil 6 continues to increase, the pressure inside the air cavity 21 will rise accordingly. Under the pressure difference, the diaphragm 34 will bulge, and its edge will move upwards and align with the inlet 312. At this time, the desiccant 33 on the diaphragm 34 will move towards the inlet 312 under the inclined guiding action of the bulge, and enter the receiving groove 311 through the inlet 312, allowing the desiccant 33 to return from the moisture-absorbing layer 35 to the receiving groove 311. Thus, the rising and falling of the floating seal 32 and the deformation of the diaphragm 34 can jointly complete the release and recovery of the desiccant 33.

[0031] In this embodiment, the receiving tank 311 is arranged in an annular shape, with both the inlet 312 and the outlet 313 extending circumferentially along the mounting pipe 31 to form an annular structure. The annular receiving tank 311 can store desiccant 33 around the mounting pipe 31, and the annular outlet 313 can release desiccant 33 circumferentially, allowing the moisture-absorbing layer 35 to be continuously formed circumferentially along the mounting pipe 31. The annular inlet 312 can receive desiccant 33 returning from the edge of the diaphragm 34 circumferentially, reducing the problem of insufficient local recovery.

[0032] A heating device is installed inside the receiving tank 311 to heat and regenerate the desiccant 33 entering the receiving tank 311. The heating device includes an annular heating element 36 disposed inside the receiving tank 311, extending circumferentially along the receiving tank 311. The annular heating element 36 can be an electric heating wire, an annular heating plate, or other components capable of heating the desiccant 33. After the desiccant 33 enters the receiving tank 311 through the inlet 312, the annular heating element 36 can circumferentially heat the desiccant 33, causing the moisture adsorbed by the desiccant 33 to desorb, thereby restoring the moisture absorption capacity of the desiccant 33.

[0033] A baffle ring 37 is provided on the diaphragm 34 to prevent the desiccant 33 from moving towards the center of the diaphragm 34. The baffle ring 37 is located on the upper surface of the diaphragm 34 and inside the edge of the diaphragm 34. When the desiccant 33 falls onto the diaphragm 34 from the outlet 313, the baffle ring 37 can limit the desiccant 33, so that the desiccant 33 mainly stays between the outer side of the baffle ring 37 and the edge of the diaphragm 34, preventing the desiccant 33 from moving towards the center of the diaphragm 34 and affecting the diaphragm 34's depression and bulge deformation.

[0034] A guide ramp 314 is provided at the inlet 312 to guide the desiccant 33 on the diaphragm 34 into the receiving tank 311. The guide ramp 314 can be formed on the lower edge of the inlet 312 or on the inner wall of the inlet 312. When the diaphragm 34 is in the convex state, the edge of the diaphragm 34 abuts against the inlet 312, and the desiccant 33 moves from the surface of the diaphragm 34 towards the inlet 312, and then enters the receiving tank 311 under the guidance of the guide ramp 314. The guide ramp 314 can reduce the accumulation of desiccant 33 at the inlet 312, making the desiccant 33 recovery process smoother.

[0035] The outlet 313 is positioned towards the edge of the diaphragm 34 to allow the desiccant 33 to fall between the outer side of the baffle ring 37 and the edge of the diaphragm 34. The opening direction of the outlet 313 can be downward or obliquely downward towards the edge region of the diaphragm 34, allowing the desiccant 33 to fall directly to the location where the moisture-absorbing layer 35 needs to be formed after leaving the receiving tank 311. Through the cooperation between the position of the outlet 313 and the position of the baffle ring 37, the desiccant 33 can form a relatively concentrated annular accumulation area at the edge of the diaphragm 34, thereby improving the coverage of the moisture-absorbing layer 35 over the circumferential gap of the installation pipe 31.

[0036] A drying chamber 4 is installed on the oil conservator 2, filled with desiccant 33, and connected to the air chamber 21. The drying chamber 4 is used to pre-dry the outside air entering the air chamber 21. An exhaust pipe 5 is also installed on the oil conservator 2, with its bottom connected to the air chamber 21 via an exhaust check valve 51. The exhaust check valve 51 only allows gas from the air chamber 21 to be discharged outwards through the exhaust pipe 5. An intake check valve 41 is installed at the connection between the drying chamber 4 and the air chamber 21, allowing outside air to enter the air chamber 21 only through the drying chamber 4. When the air chamber 21 experiences negative pressure, the intake check valve 41 opens, allowing outside air to enter the air chamber 21 after dehumidification by the drying chamber 4; when the air chamber 21 experiences positive pressure, the exhaust check valve 51 opens, allowing gas from the air chamber 21 to be discharged through the exhaust pipe 5.

[0037] An exhaust chamber 315 is connected to the middle of the receiving tank 311. An annular heating element 36 is located below the exhaust chamber 315. A filter screen 316 is provided between the receiving tank 311 and the exhaust chamber 315 to prevent the desiccant 33 from passing through. The exhaust chamber 315 is connected to a connecting channel 317 that connects to the air chamber 21. The filter screen 316 allows gas and water vapor to pass through, but prevents particulate desiccant 33 from entering the exhaust chamber 315. When the annular heating element 36 heats and regenerates the desiccant 33 in the receiving tank 311, the moisture released by the desiccant 33 can enter the exhaust chamber 315 through the filter screen 316, and then enter the air chamber 21 through the connecting channel 317. Subsequently, it is discharged through the exhaust pipe 5 when the air chamber 21 exhausts gas outward.

[0038] Working principle: During normal operation, the floating seal 32 covers the insulating oil 6 and rises and falls with the level of the insulating oil 6 in the oil tank 2, keeping the insulating oil 6 isolated from the air cavity 21. The pressure in the air cavity 21 changes with the volume of the insulating oil 6. The inlet check valve 41 and the exhaust check valve 51 control the inlet and exhaust directions respectively, so that the air cavity 21 can maintain pressure balance. When the ambient temperature decreases or the transformer load decreases, the volume of the insulating oil 6 shrinks, and the floating seal 32 descends with the insulating oil 6. When the floating seal 32 descends to the lower limit, if the insulating oil 6 continues to shrink, the diaphragm 34 is indented under the action of pressure difference. The edge of the diaphragm 34 is lower than the outlet 313, and the desiccant 33 falls from the receiving tank 311 through the outlet 313 to the edge of the diaphragm 34, forming a moisture-absorbing layer 35 between the edge of the diaphragm 34 and the installation pipe 31. At the same time, negative pressure is formed in the air cavity 21, the air inlet one-way valve 41 is opened, and the outside air enters the air cavity 21 after being dried by the drying box 4. The moisture-absorbing layer 35 continues to adsorb the water vapor that may enter the insulating oil 6 side around the installation pipe 31.

[0039] When the ambient temperature rises or the transformer load increases, the insulating oil 6 expands in volume, and the floating seal 32 rises with the insulating oil 6. When the floating seal 32 rises to its upper limit, if the insulating oil 6 continues to expand, the diaphragm 34 bulges under the action of pressure difference, and the edge of the diaphragm 34 aligns with the inlet 312. The desiccant 33 on the diaphragm 34 enters the receiving tank 311 through the guide slope 314. Subsequently, the annular heating element 36 heats and regenerates the desiccant 33 in the receiving tank 311. The moisture released by the desiccant 33 enters the exhaust chamber 315 through the filter screen 316, and then enters the air chamber 21 through the connecting channel 317. After the pressure in the air chamber 21 increases, the exhaust check valve 51 opens, and the gas in the air chamber 21 is discharged to the outside through the exhaust pipe 5. Through the above process, the compensation component 3 can automatically complete the release, moisture absorption, recovery, and regeneration of the desiccant 33 by utilizing the lifting motion generated by the volume change of the insulating oil 6, reducing the probability of the insulating oil 6 coming into contact with humid air and delaying the moisture absorption and oxidation of the insulating oil 6.

[0040] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An open-type oil-immersed transformer, comprising an oil tank, an oil conservator communicating with the oil tank, and a transformer body disposed within the oil tank, wherein the oil conservator has an air cavity located above the insulating oil, characterized in that: A compensation component is provided within the oil conservator. The compensation component includes an installation pipe and a floating seal. The installation pipe is vertically disposed within the oil conservator, and its interior or periphery forms a ventilation space related to the air cavity. The floating seal covers the surface of the insulating oil and is slidably disposed within the installation pipe, rising and falling with the volume change of the insulating oil to isolate the insulating oil from the air cavity. The installation pipe is provided with a receiving groove filled with granular desiccant, and the receiving groove has an inlet and an outlet. A diaphragm is provided on the floating seal. When the floating seal is at its lower limit position, the diaphragm is recessed due to the pressure difference, and its edge is lower than the outlet, so that the desiccant falls onto the diaphragm and forms a moisture-absorbing layer between the edge of the diaphragm and the installation pipe. When the floating seal is at its upper limit position, the diaphragm bulges due to the pressure difference, and its edge aligns with the inlet, so that the desiccant enters the receiving groove.

2. The open-type oil-immersed transformer according to claim 1, characterized in that, The receiving groove is arranged in a ring shape, and both the inlet and the outlet extend circumferentially along the installation pipe to form a ring.

3. The open-type oil-immersed transformer according to claim 2, characterized in that, The container is equipped with a heating device, which is used to heat and regenerate the desiccant entering the container.

4. The open-type oil-immersed transformer according to claim 3, characterized in that, The heating device includes an annular heating element disposed inside the receiving groove, the annular heating element extending circumferentially along the receiving groove.

5. The open-type oil-immersed transformer according to claim 4, characterized in that, A baffle ring is provided on the diaphragm to prevent the desiccant from moving toward the center of the diaphragm.

6. The open-type oil-immersed transformer according to claim 1, characterized in that, The inlet is provided with a guide slope, which is used to guide the desiccant on the diaphragm into the receiving tank.

7. The open-type oil-immersed transformer according to claim 5, characterized in that, The outlet is positioned toward the edge of the diaphragm to allow the desiccant to fall between the outer side of the baffle ring and the edge of the diaphragm.

8. The open-type oil-immersed transformer according to claim 4, characterized in that, A drying chamber is installed on the oil reservoir, the drying chamber is filled with desiccant, and the drying chamber is connected to the air cavity.

9. The open-type oil-immersed transformer according to claim 8, characterized in that, An exhaust pipe is provided on the oil tank. The bottom of the exhaust pipe is connected to the air chamber through an exhaust one-way valve. The exhaust one-way valve only allows the gas in the air chamber to be discharged outward through the exhaust pipe. An air inlet one-way valve is provided at the connection between the drying chamber and the air chamber. The air inlet one-way valve only allows outside air to enter the air chamber through the drying chamber.

10. The open-type oil-immersed transformer according to claim 9, characterized in that, The middle part of the receiving tank is connected to an exhaust chamber, the annular heating element is located below the exhaust chamber, a filter screen is provided between the receiving tank and the exhaust chamber to block the passage of desiccant, and the exhaust chamber is connected to a connecting channel that connects to the air chamber.

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