Vertical external oil metal corrugated oil conservator for high-capacity transformer

Abstract

The utility model belongs to the technical field of transformer oil storage compensation equipment in the electric power transformation industry, and particularly relates to a vertical external oil metal corrugated oil conservator for a high-capacity transformer, which adopts an arrangement mode that a metal corrugated expansion core body is transversely arranged, so that the length of the oil conservator is greatly reduced, the oil conservator is more convenient to produce, transport and install, and the production cost is reduced. A plurality of cabinet legs do not need to be arranged; the length-width ratio of the oil conservator is optimized, so that more reinforcing structures do not need to be designed to improve the bending resistance of the oil conservator, the manufacturing cost of the large-capacity oil conservator is greatly reduced, and the large-capacity oil conservator is more suitable for large transformation equipment. According to the metal corrugated oil conservator, the length of the metal corrugated oil conservator body is shortened, the width of the metal corrugated oil conservator body is increased, the length-width ratio of the oil conservator is small, the overall appearance of the oil conservator is shorter, the bending resistance of the metal corrugated oil conservator legs is increased by geometric multiples, many bending resistance auxiliary structures can be omitted, and the manufacturing cost of the metal corrugated oil conservator is correspondingly reduced.

Description

Technical Field

[0001] This utility model belongs to the technical field of transformer oil storage compensation equipment in the power substation industry. Specifically, it is a vertical external metal corrugated oil storage tank for large-capacity transformers, which can be applied to substation systems. Background Technology

[0002] In substation systems, oil-immersed transformers are typically equipped with metal corrugated oil conservators to address a series of problems caused by changes in the volume of transformer oil due to temperature variations.

[0003] Currently, the application of corrugated metal oil conservators is relatively mature, mainly in two forms: internal oil type and external oil type. Internal oil type refers to storing transformer oil inside the corrugated metal expansion core of the conservator, while external oil type refers to storing transformer oil in the cavity formed between the outer surface of the corrugated metal expansion core and the conservator body. Internal oil conservators are more widely used due to their simpler manufacturing process.

[0004] Because the corrugated expansion core of a corrugated metal oil tank is an elastic element, the characteristics of elastic elements determine that a circular or near-circular cross-section has better stability and durability. Therefore, the cross-section of the corrugated expansion core inside a corrugated metal oil tank is usually a perfect circle or a near-circular racetrack shape, such as... Figure 1 As shown, the aspect ratio of the cross-section of the corrugated metal expansion core 2 is approximately 2:1. Due to limitations in material properties and processing equipment, the maximum cross-sectional size of the corrugated metal expansion core is usually no more than 3 meters; and to ensure good elasticity, the corrugation number of the corrugated metal expansion core should not be too high, and the unfolded height is usually within 1.5 meters. Therefore, the maximum compensation volume of a single corrugated metal expansion core is usually around 3 cubic meters.

[0005] When selecting an oil conservator for a transformer with high oil storage requirements, a single corrugated metal expansion core cannot meet the needs. The conventional design solution is as follows: Figure 2 , Figure 3 As shown, multiple corrugated metal expansion cores 2 are connected in parallel through oil pipelines 4 to form a multi-core corrugated metal oil tank. The multiple cores are connected through oil pipelines 4 to obtain a larger capacity.

[0006] The arrangement of multiple cores is usually parallel along the length of the racetrack-shaped corrugated metal expansion core, resulting in a slender overall appearance with a large length-to-width ratio, similar to the common parallel corrugated metal oil tanks on the market.

[0007] In recent years, with the upgrading of my country's power transmission and transformation system, the voltage level and oil storage compensation requirements of transformers have been increasing, with some ultra-high voltage and ultra-large capacity transformers requiring compensation of over 15 cubic meters. When using metal corrugated oil conservators for some ultra-high voltage and ultra-large capacity transformers, conventional design schemes have some shortcomings. These are mainly reflected in the following points:

[0008] 1. The oil tank is too long. To achieve a compensation capacity of 15 cubic meters or more, at least five cores need to be connected in parallel. If they are connected in parallel along the length of the racetrack-shaped corrugated metal expansion cores, the length-to-width ratio of the entire oil tank will reach 10:1, and the length of the oil tank will be more than 15 meters; this is very inconvenient during production, transportation and installation.

[0009] 2. Corrugated metal oil tanks are usually connected to transformers via steel legs. Excessively long oil tanks require more legs due to insufficient support, and the arrangement and production of multiple legs are quite difficult.

[0010] 3. An excessively large length-to-width ratio reduces the bending resistance of the cabinet structure, especially during lifting, when the cabinet is subjected to a large bending moment, which can easily cause cabinet deformation or weld leakage; therefore, more materials and structures are needed to improve bending resistance, which increases manufacturing costs.

[0011] 4. Multiple cores are connected by oil pipelines, requiring a large number of oil pipelines. More connection points bring more potential leakage risks.

[0012] 5. Multiple cores are connected in parallel through oil pipelines. Due to the pressure difference in the pipelines, the synchronization of the cores is poor, which may lead to inaccurate oil levels and pose a safety hazard to the transformer.

[0013] 6. Due to the increased oil storage capacity, the oil drainage rate is too low when it is necessary to drain the transformer oil in case of an emergency. Utility Model Content

[0014] To address the problems of excessively large aspect ratio, poor core synchronization, and excessively low oil discharge speed in large-capacity corrugated metal oil conservators, this utility model provides a vertical external metal corrugated metal oil conservator for large-capacity transformers.

[0015] The objective of this utility model is achieved through the following technical solution:

[0016] This utility model includes a closed cabinet and at least three corrugated metal expansion cores disposed within the closed cabinet. The corrugated metal expansion cores are arranged side-by-side along the length of the closed cabinet, and the length direction of each corrugated metal expansion core is in the same direction as the width direction of the closed cabinet. The upper end of each corrugated metal expansion core is mounted on the closed cabinet, and the lower end of each corrugated metal expansion core is a free end. The expansion and contraction direction of each corrugated metal expansion core is vertical. A breathing pipe is provided at the top of the closed cabinet, and the breathing pipe communicates with the interior of each corrugated metal expansion core. An oil supply pipe and an exhaust pipe are respectively installed at the bottom of the closed cabinet. One end of the oil supply pipe communicates with an oil cavity formed by the interior of the closed cabinet and the exterior of each corrugated metal expansion core, and the other end of the oil supply pipe is sealed and connected to a transformer. One end of the exhaust pipe communicates with the upper part of the closed cabinet, and the other end of the exhaust pipe is open to the outside atmosphere.

[0017] Wherein: the breathing pipeline is equipped with an air pump for replenishing air during rapid oil drainage. The breathing pipeline and the air pump are both located outside the enclosed cabinet. Each of the metal corrugated expansion cores is equipped with a breathing pipe on its upper part. The breathing pipes are connected in parallel to form a breathing pipeline.

[0018] Each of the breathing tubes passes through the top of the enclosed cabinet.

[0019] The other end of the oil pipeline is provided with a tee. The first port of the tee is connected to the other end of the oil pipeline, the second port of the tee is connected to the transformer through the pipeline, the third port of the tee is connected to the input end of the oil discharge pump, and the output end of the oil discharge pump is connected to the buffer container.

[0020] An oil discharge valve is provided between the input end of the oil discharge pump and the third port of the tee.

[0021] The bottom of the enclosed cabinet is equipped with cabinet feet.

[0022] The advantages and positive effects of this utility model are as follows:

[0023] 1. This utility model significantly shortens the length of the cabinet compared to the traditional parallel-type corrugated metal oil tank, greatly facilitating the production, transportation and installation of the corrugated metal oil tank.

[0024] 2. The oil storage tank of this utility model has a small length-to-width ratio and a shorter overall shape, which greatly reduces the difficulty of arranging the tank legs and manufacturing.

[0025] 3. This utility model shortens the length of the metal corrugated oil tank body and increases the width of the metal corrugated oil tank body, which increases the bending resistance of the metal corrugated oil tank legs geometrically. Many bending-resistant auxiliary structures can be omitted, and the manufacturing cost is reduced accordingly.

[0026] 4. The various corrugated metal expansion cores of this invention are not connected by oil pipelines, which greatly reduces the risk of pipeline leakage.

[0027] 5. This utility model adopts an external oil structure, with different metal corrugated expansion cores connected by a breathing pipe, resulting in a small pressure difference and high synchronization of each metal corrugated expansion core, eliminating the hidden danger of poor core synchronization and inaccurate oil level; the external breathing pipe reduces the dead zone volume of traditional oil tanks and improves the effective compensation amount.

[0028] 6. This utility model adopts an external oil structure, with the breathing pipe passing through the oil tank cabinet and connecting to the core, without occupying the internal space of the core, which is equivalent to increasing the effective compensation volume.

[0029] 7. This utility model adds an oil drain pump for rapid oil drainage and an air pump for replenishing air, thereby achieving rapid oil drainage and improving the oil tank's ability to withstand accidental leaks or fires. Attached Figure Description

[0030] Figure 1 A schematic diagram of the cross-section of a racetrack-shaped corrugated metal expansion core;

[0031] Figure 2 A schematic diagram of a traditional multi-core oil tank connected in parallel along the length of a corrugated metal expansion core.

[0032] Figure 3 for Figure 2 Top view;

[0033] Figure 4 This is a schematic diagram of the overall structure of this utility model;

[0034] Figure 5 for Figure 4 Top view;

[0035] Among them: 1 is the enclosed cabinet, 2 is the corrugated metal expansion core, 3 is the breathing pipe, 4 is the oil supply pipe, 5 is the cabinet foot, 6 is the exhaust pipe, 7 is the air pump, 8 is the oil drain pump, 9 is the oil drain valve, 10 is the slow-release container, 11 is the transformer, and 12 is the tee. Detailed Implementation

[0036] The present invention will now be described in further detail with reference to the accompanying drawings.

[0037] like Figure 4 , Figure 5As shown, this utility model includes a closed cabinet 1 and at least three corrugated metal expansion cores 2 disposed within the closed cabinet 1. The corrugated metal expansion cores 2 are arranged side-by-side along the length of the closed cabinet 1, and the length direction of each corrugated metal expansion core 2 is in the same direction as the width direction of the closed cabinet 1. The upper end of each corrugated metal expansion core 2 is mounted on the closed cabinet 1, and the lower end of each corrugated metal expansion core 2 is a free end. The expansion and contraction direction of each corrugated metal expansion core 2 is vertical. A breathing tube 3 is provided at the top of the closed cabinet 1 for breathing... Pipeline 3 is connected to the interior of each metal corrugated expansion core 2; oil supply pipeline 4 and exhaust pipeline 6 are respectively installed at the bottom of the enclosed cabinet 1. One end of oil supply pipeline 4 is connected to the oil cavity formed by the interior of the enclosed cabinet 1 and the exterior of each metal corrugated expansion core 2, and the other end of oil supply pipeline 4 is sealed and connected to transformer 11; one end (top) of exhaust pipeline 6 is connected to the upper part of the enclosed cabinet 1, and the other end (bottom) of exhaust pipeline 6 extends from the bottom of the enclosed cabinet 1 and is connected to the outside atmosphere, used to discharge the gas in the enclosed cabinet 1 during the first oil filling.

[0038] In this embodiment, there are five corrugated metal expansion cores 2 with a racetrack-shaped cross-section. There is no oil pipeline connection between the five corrugated metal expansion cores 2. By using five corrugated metal expansion cores 2, a large compensation volume (reaching 15 cubic meters or more) is obtained, which meets the compensation requirements of large-capacity transformers.

[0039] In this embodiment, the breathing tubing 3 is equipped with an air pump 7 for replenishing air during rapid oil drainage. Both the breathing tubing 3 and the air pump 7 are located outside the enclosed cabinet 1. Each corrugated metal expansion core 2 has a breathing tube on its upper part, and each breathing tube passes through the top of the enclosed cabinet 1. The breathing tubes are connected in parallel to form the breathing tubing 3, which is used for the breathing of each corrugated metal expansion core 2 during operation. The air pump 7 is powered by electricity.

[0040] In this embodiment, the space enclosed by the outer surface of each corrugated metal expansion core 2 and the inner surface of the enclosed cabinet 1 constitutes the expansion space of the corrugated metal expansion core 2. In this embodiment, only the oil supply pipeline 4, which is sealed and connected to the transformer 11, is installed at the bottom of the enclosed cabinet 1, forming a fully sealed oil circuit. A tee 12 is provided at the other end of the oil supply pipeline 4. The first port of the tee 12 is connected to the other end of the oil supply pipeline 4, the second port of the tee 12 is connected to the transformer 11 via a pipeline, and the third port of the tee is connected to the input end of the oil discharge pump 8. The output end of the oil discharge pump 8 is connected to the buffer container 10. An oil discharge valve 9 is provided between the input end of the oil discharge pump 8 and the third port of the tee. The oil discharge pump 8 is powered by electricity and is used for rapid oil discharge.

[0041] In this embodiment, cabinet feet 5 are provided at the bottom of the enclosed cabinet 1.

[0042] The working principle of this utility model is as follows:

[0043] This utility model uses multiple corrugated metal expansion cores 2 as compensation devices. The corrugated metal expansion cores 2 and the enclosed cabinet 1 form a sealed structure to store transformer oil. The expansion and contraction of the multiple corrugated metal expansion cores 2 compensate for changes in the volume of the transformer oil.

[0044] When the temperature of transformer 11 rises, the transformer oil expands, and the excess oil enters the enclosed cabinet 1 through the oil supply pipe 4. At this time, each metal corrugated expansion core 2 moves vertically upward synchronously and is in a contracted state. The gas inside each metal corrugated expansion core 2 is discharged to the atmosphere through the breather pipe 3. When the temperature of transformer 11 decreases, the transformer oil contracts, and the transformer oil in the enclosed cabinet 1 flows back into transformer 11 through the oil supply pipe 4. At this time, each metal corrugated expansion core 2 moves vertically downward and is in an expanded state, using the change in volume to compensate for the change in the volume of the transformer oil in the enclosed cabinet 1. At this time, a brief low pressure appears inside each metal corrugated expansion core 4, and the atmosphere compensates for this by flowing into the metal corrugated expansion core 2 through the breather pipe 3.

[0045] When rapid oil drainage is required, air pump 7 starts, injecting air into each metal corrugated expansion core 2 through breather pipe 3; simultaneously, oil drain pump 8 starts, oil drain valve 9 opens, and transformer oil in the enclosed cabinet 1 is quickly drained into buffer container 10 through oil delivery pipe 4. This rapid oil drainage prevents losses due to transformer oil leakage or fire caused by accidental leaks or fire.

[0046] This invention, based on existing multi-core corrugated metal oil tanks, modifies the arrangement of the corrugated expansion cores 2 to solve a series of problems caused by the excessive length of large-capacity multi-core corrugated metal oil tanks; and adopts an external oil structure, solving the problems of multiple connecting pipelines and poor core synchronization. This invention also adds a rapid oil discharge structure to solve the problem of excessively low oil discharge speed when oil discharge is required in special circumstances.

Claims

1. A vertical external metal corrugated oil conservator for a large-capacity transformer, comprising a closed cabinet (1) and at least three metal corrugated expansion cores (2) disposed within the closed cabinet (1), characterized in that: Each of the aforementioned corrugated metal expansion cores (2) is arranged side by side along the length direction of the enclosed cabinet (1), and the length direction of each of the aforementioned corrugated metal expansion cores (2) is in the same direction as the width direction of the enclosed cabinet (1); the upper end of each of the aforementioned corrugated metal expansion cores (2) is mounted on the enclosed cabinet (1), the lower end of each of the aforementioned corrugated metal expansion cores (2) is a free end, and the expansion and contraction direction of each of the aforementioned corrugated metal expansion cores (2) is vertical; a breathing tube (3) is provided at the top of the enclosed cabinet (1), and the breathing tube... The oil pipeline (3) is connected to the interior of each metal corrugated expansion core (2); the bottom of the enclosed cabinet (1) is respectively equipped with an oil pipeline (4) and an exhaust pipeline (6). One end of the oil pipeline (4) is connected to the oil cavity formed by the interior of the enclosed cabinet (1) and the exterior of each metal corrugated expansion core (2), and the other end of the oil pipeline (4) is sealed and connected to the transformer (11); one end of the exhaust pipeline (6) is connected to the upper part inside the enclosed cabinet (1), and the other end of the exhaust pipeline (6) is connected to the outside atmosphere.

2. The vertical external metal corrugated oil conservator for large-capacity transformers according to claim 1, characterized in that: The breathing tubing (3) is equipped with an air pump (7) for replenishing air during rapid oil drainage. The breathing tubing (3) and the air pump (7) are both located outside the enclosed cabinet (1). Each of the metal corrugated expansion cores (2) is equipped with a breathing tube on its upper part. The breathing tubes are connected in parallel to form the breathing tubing (3).

3. The vertical external metal corrugated oil conservator for large-capacity transformers according to claim 2, characterized in that: Each of the breathing tubes passes through the top of the enclosed cabinet (1).

4. The vertical external metal corrugated oil conservator for large-capacity transformers according to claim 1, characterized in that: The other end of the oil pipeline (4) is provided with a tee (12). The first port of the tee (12) is connected to the other end of the oil pipeline (4). The second port of the tee (12) is connected to the transformer (11) through the pipeline. The third port of the tee is connected to the input end of the oil discharge pump (8). The output end of the oil discharge pump (8) is connected to the buffer container (10).

5. The vertical external metal corrugated oil conservator for large-capacity transformers according to claim 4, characterized in that: An oil discharge valve (9) is provided between the input end of the oil discharge pump (8) and the third port of the tee.

6. The vertical external metal corrugated oil conservator for large-capacity transformers according to claim 1, characterized in that: The bottom of the enclosed cabinet (1) is provided with cabinet feet (5).

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