Transformer oil recovery device

Abstract

The method relates to a transformer oil recovery apparatus that provides improved transformer oil recovery using a cartridge system. In addition, the invention relates to a cabinet comprising the transformer oil recovery device. In addition, the invention relates to a transformer oil recovery method using such a cartridge system.

Description

Technical Field

[0001] This method relates to a transformer oil recovery device that provides improved transformer oil recovery. Furthermore, this invention relates to a cabinet incorporating such a transformer oil recovery device. Additionally, this invention relates to a transformer oil recovery method. Background Technology

[0002] For example, transformers are a crucial component of the power grid and, in this case, an essential part of modern society. While they have been standard components used for decades, they continue to be improved. In particular, demands arising from changing needs, such as variations in the amount of renewable energy introduced into such grids and changes in societal electricity demand, create additional burdens that need to be addressed. This refers, for example, to increased electricity consumption and dependence on it by society and industry. For instance, changes in heating systems, such as the introduction of heat exchangers as a common heating source for homes, are expected to only increase this. If the power grid fails during peak winter loads, leaving thousands of homes without heating, significant problems will arise.

[0003] A crucial component of high-power transformers used in power grids is the isolator, essential for ensuring safe and efficient operation. Here, components such as the oil must meet a wide range of requirements to operate at very high temperatures, provide cooling, and offer insulation. Ensuring the long-term use of this oil necessitates its recycling and the removal of contaminants and moisture to maintain its performance. However, existing methods for recycling transformer oil still offer opportunities for further improvement. For example, existing methods have limitations, such as the ability to quickly adapt to changing needs and to provide highly reliable transformer oil recycling to ensure the use of the highest quality transformer oil over extended periods.

[0004] These and further problems are addressed by the products and methods disclosed below and in the claims. Further beneficial embodiments are disclosed in the dependent claims, as well as in the further description and drawings. These benefits can be used to adapt the corresponding solutions to specific needs or to solve additional problems. Summary of the Invention

[0005] According to one aspect, the present invention relates to a transformer oil recovery apparatus for recovering transformer oil, comprising: At least one, more preferably at least two oil cleaning cartridges and at least one oil drying cartridge. At least one oil cleaning cylinder has a height of up to 180 cm and a width of up to 30 cm. The aspect ratio of height to width is at most 12:1. At least one oil drying cylinder has a height of up to 180 cm and a width of up to 30 cm. The aspect ratio of height to width is at most 12:1. At least one of the oil cleaning cartridges contains fuller earth to absorb contaminants from the oil. At least one oil drying cylinder contains a molecular sieve to absorb moisture from the oil.

[0006] Surprisingly, even compared to other systems containing, for example, absorbents (which are considered to offer higher performance, such as activated alumina, bentonite, diatomaceous earth, silica gel, activated carbon, etc.), the system of the present invention, combining an oil cleaning cylinder of a specific size containing bleaching clay and an oil drying cylinder of a specific size containing molecular sieves, provides improved performance. The inventors have noted, surprisingly, that flexible and particularly efficient transformer oil recovery can be achieved using this cylinder. Not only can small transformer oil recovery devices be realized, which are easy to install in existing facilities and can be retrofitted to these facilities using continuous oil recovery, offering significant benefits, for example, compared to discontinuous oil regeneration. Furthermore, the corresponding cylinders can be easily handled using existing equipment, improving the overall safety of personnel responsible for operating the transformer oil recovery device. In particular, it is noteworthy that the reliability of oil recovery using the disclosed transformer oil recovery device is surprisingly high. Typically, it should be expected that using particularly small cylinders would primarily require numerous replacements, which only increases labor without providing any benefit. However, providing such a cylinder-based system, even allowing adaptation to specific needs noted in the short term, surprisingly compensates for this replacement requirement. Adaptive strategies can even be provided, as real-world applications present varying requirements for drying and cleaning capabilities. For example, it is noted that drying requirements typically decrease over time once most moisture has been removed. In such cases, the number of oil cleaning cylinders can be increased to accommodate this changing demand. For instance, in situations where certain maintenance operations require the replacement of transformers or transformer oil, an even greater number of oil drying cylinders can be used to meet this need. Here, the optimal combination of bleaching clay and molecular sieves with specific sizes provides the best approach to this beneficial transformer oil recovery process.

[0007] According to another aspect, the present invention relates to a cabinet incorporating the transformer oil recovery device of the present invention.

[0008] According to another aspect, the present invention relates to a method for recovering transformer oil, wherein the method uses the transformer oil recovery device of the present invention. The method includes the step of removing contaminants from transformer oil using at least one oil cleaning cartridge, and The method includes the step of removing contaminants from transformer oil using at least one oil drying cylinder.

[0009] To simplify the understanding of the invention, reference is made to the following detailed description and accompanying drawings, which are also described herein. The drawings should be understood not to limit the scope of the invention, but rather to disclose preferred embodiments that further explain the invention. Attached Figure Description

[0010] Figure 1 A schematic diagram of a cabinet containing a transformer oil recovery unit is shown. Detailed Implementation

[0011] According to one aspect, the present invention relates to a transformer oil recovery device as described above.

[0012] Those skilled in the art know that bleaching clay is a variety of clays used as absorbents, filters, or bleaching agents. Examples of bleaching clays that have been noted as particularly beneficial for transformer oil recovery processes include COFERMIN bauxite, PETROCHEM bauxite, Newport bauxite, BOUD Minerals bauxite, OILDRI bleaching clay, Curimbaba bleaching clay, Porocel bleaching clay, JVI Minerals bleaching clay, Ashapura bleaching clay, and READE bleaching clay. It is noted that bleaching clay is particularly suitable for use in typical transformers used in power grids. Contaminants observed in these applications are well absorbed and very effectively removed from the corresponding transformer oil. Particularly high-quality oil recovery is achieved even at the end of the life of the corresponding transformer oil cleaning cartridge.

[0013] According to a further embodiment, preferably, the molecular sieve is a 3Å molecular sieve and / or a 4Å molecular sieve. It is noted that the corresponding molecular sieve is well-suited for typical applications.

[0014] According to a further embodiment, preferably, the transformer oil recovery device includes a moisture sensor. Integrating a corresponding moisture sensor allows for further improvement in the possibility of monitoring the state of the corresponding cylinder and ultimately detecting irregularities and the increased need for moisture removal from the oil. While seemingly simple, it is noteworthy that in real-world applications, such a simple additional sensor allows for the detection of abnormal moisture content in the transformer oil. Providing such a typically less useful additional sensor, based on the typical, well-predictable characteristics and moisture content of transformer oil, would be highly beneficial based on indirect inferences that can be derived from it. Typical sources of this moisture, such as paper used in such transformers, release moisture slowly over time due to depolymerization, allowing for a simple calculation of the time when a corresponding moisture absorbent can be used. This makes such a sensor less useful. However, it is noted that corresponding deviations from this calculated characteristic can be used to identify problems at an early stage, or even prevent the development of problems. Typically, preferably, the moisture sensor is located after at least one transformer oil drying cylinder. According to a further embodiment, preferably, based on the expected flow direction of the transformer oil through at least one transformer oil drying cylinder, the transformer oil recovery device includes at least one moisture sensor before at least one transformer oil drying cylinder and at least one moisture sensor after at least one transformer oil drying cylinder. This allows for the safe provision of additional data on the drying characteristics of the transformer oil dryer to provide further insights, such as the saturation of the transformer oil dryer with other substances, thereby providing a deeper understanding of the transformer.

[0015] According to a further embodiment, preferably, at least one oil cleaning cartridge has a height of at least 70 cm measured from the top to the bottom of the oil cleaning cartridge, and a width of at least 10 cm. The aspect ratio of height to width must be at least 4:1. At least one oil drying cylinder has a height of at least 70 cm measured from the top to the bottom of the oil drying cylinder, and a width of at least 10 cm. The aspect ratio of height to width must be at least 4:1. At least one oil cleaning cylinder has a height of at least 80 cm and a width of at least 12 cm. At least one oil drying cylinder has a height of at least 80 cm and a width of at least 12 cm. More preferably, at least one oil cleaning cylinder has a height of at least 100 cm and a width of at least 15 cm. At least one oil drying cylinder has a height of at least 100 cm and a width of at least 15 cm. While their flexibility and versatility in adapting to spontaneous needs remain central to this invention, it is noted that increasing the size of such cylinders provides a far less loss of this flexibility than intended. Furthermore, for typical applications such as high-performance transformers used in power grids, it allows for a significant reduction in the number of oil changes required for transformer oil recovery, easily compensating for losses due to, for example, early replacement of partially used cylinders. This design is particularly beneficial for power grid applications.

[0016] According to a further embodiment, it is preferred that the height-to-width ratio is at least 5:1, and even more preferably at least 6:1. While a higher aspect ratio should be expected to produce contradictory effects, it should be noted that, typically, using such a high aspect ratio is beneficial.

[0017] According to a further embodiment, preferably, at least one oil cleaning cylinder has a height of up to 155 cm and a width of up to 24 cm. At least one oil drying cylinder has a height of up to 155 cm and a width of up to 24 cm. The aspect ratio of height to width is at most 10:1. More preferably, at least one oil cleaning cylinder has a height of up to 140 cm and a width of up to 22 cm. At least one oil drying cylinder has a height of at most 140 cm and a width of at most 22 cm. The aspect ratio of height to width is at most 9:1.

[0018] It is worth noting that this design of the oil cleaning and drying cylinders is particularly suitable for use in cabinets, allowing easy access to the cylinders. While the use of larger cylinders should be expected to be preferred, thus allowing for fewer replacements, this size has been found particularly well-suited for transformer oil recovery, especially for cabinet solutions, because, under real-world conditions, typical personnel responsible for such transformers find solutions of this size highly beneficial. In particular, considering the recent increase in the possibility of remote monitoring of the corresponding transformers and the reduction in the need for responsible personnel due to improved transformer reliability, solutions must be provided that simplify operation, require fewer personnel, and reduce the risk of serious injury in the event of minor errors during operation.

[0019] According to a further embodiment, preferably, the transformer oil recovery equipment is adapted to allow the transformer oil to flow through the transformer oil recovery device in the direction of flow, and the transformer oil recovery device provides a transformer oil inlet and a transformer oil outlet. In cases where there is only one oil drying cylinder, the oil drying cylinder is located at the transformer oil outlet; or in cases where there are two or more oil drying cylinders, at least one of the at least one drying cylinders is located at the transformer oil outlet. It is noted that allowing the transformer oil to flow through the oil drying cylinders last appears to improve the drying process, thereby significantly increasing the oil drying rate. For typical embodiments, it is preferred that, in cases where the transformer oil recovery device includes at least two oil drying cylinders, at least two oil drying cylinders are located at the transformer oil outlet; more preferably, in cases where the transformer oil recovery device includes at least three oil drying cylinders, at least three oil drying cylinders are located at the transformer oil outlet. While a single oil drying cylinder can be placed initially, particularly between at least one oil cleaning cylinder, it is surprisingly advantageous to place more oil drying cylinders at the end. In particular, it is preferable that all oil drying cylinders are located at the transformer oil outlet of the transformer oil recovery device, based on the flow direction of the transformer oil during transformer oil recovery.

[0020] According to a further embodiment, preferably, the transformer oil recovery device is adapted to allow the transformer oil to flow through it in a direction that facilitates the recovery of the transformer oil. The transformer oil recovery device provides a transformer oil inlet and a transformer oil outlet. In cases where there is only one oil cleaning cylinder, the oil cleaning cylinder is located at the transformer oil inlet; or in cases where there are two or more oil cleaning cylinders, at least one of the at least one cleaning cylinders is located at the transformer oil inlet. It should be noted that in typical applications, it can sometimes be difficult to ensure a low moisture content in the bleaching soil. Placing at least one oil cleaning cylinder at the inlet of the transformer oil passage through the transformer oil recovery device allows for easy assurance that the drying effect of the subsequent oil drying cylinder is fully utilized. It also allows for the removal of moisture released by the bleaching soil. In real-world conditions, a real problem arises based on, for example, variations in the moisture content of the bleaching soil or other deviations. For typical embodiments, it is preferred that, based on the transformer oil recovery device's suitability for the flow direction of the supplied transformer oil, in the case where the transformer oil recovery device includes at least two oil cleaning cylinders, at least two cleaning cylinders are located before at least one oil drying cylinder; more preferably, in the case where the transformer oil recovery device includes at least three oil cleaning cylinders, at least three oil cleaning cylinders are located before at least one oil drying cylinder. While it is also possible to place oil cleaning cylinders between at least one oil drying cylinder, it is typically preferred that at least most of the oil cleaning cylinders are placed before the oil drying cylinder. In particular, preferably, based on the flow direction of the transformer oil being supplied by the transformer oil recovery device, all oil cleaning cylinders are located before at least one oil drying cylinder.

[0021] According to a further embodiment, preferably, a cleaning cartridge fastening system is used, and at least one oil drying cartridge is fastened by the drying cartridge fastening system. The cleaning cylinder fastening system and / or drying cylinder fastening system are suitable for replacing at least one cleaning cylinder and / or at least one drying cylinder without the use of tools. It is noted that the use of a cylinder system as described above requires repeated cylinder replacements, which makes this type of fastening mechanism typically advantageous. While the additional effort, such as using a wrench to tighten the corresponding cylinder, is not a significant extra effort, it is noteworthy that this different fastening system, which does not require specific tools, is surprisingly beneficial. In particular, tests have shown that personnel responsible for operating the corresponding transformer oil recovery device often forget or misplace the corresponding tools. If personnel attempt to keep the cylinder in place while reaching for tools that are too far away, it increases safety-related problems. This is easily resolved with the fastening system described above. In this context, it is noted that the fastening system described above is particularly suitable for safety improvements under real-world conditions.

[0022] According to a further embodiment, preferably, the transformer oil recovery device includes a filter, and based on the flow direction of the transformer oil recovery device to allow the transformer oil recovery flow through the device, the filter is located before or after at least one oil cleaning cylinder, preferably after. Typically, preferably, such a filter is located before or after at least one oil cleaning cylinder and at least one oil drying cylinder, preferably after. It is noted that this seemingly simple addition of a filter allows for a significant improvement in the reliability of providing high-quality recovered transformer oil. While it should be expected that small particles should have been safely removed as they pass through the particular cylinder, it is noted that this still provides a significant improvement. It is particularly surprising that the filter is placed after the cylinder. While the invention should not be considered as a limitation based on this theory, the inventors assume that very small particles are passing through or being released from the bleaching soil in the cleaning cylinder. Such a filter is beneficial even when at least one oil drying cylinder is located after at least one cleaning cylinder.

[0023] According to a further embodiment, preferably, the filter provides a pore size of less than 10 micrometers, more preferably less than 6 micrometers, and even more preferably less than 5 micrometers. This pore size can be determined using commonly available methods, such as those specified in ISO 16889. It is noteworthy that transformer oil contains such fine particles, especially after a specific cartridge. Typically, a filter with a particle size of 30-40 micrometers is preferred. This provides a surprising and quite significant further improvement in transformer oil recovery for the transformer oil recovery device of the present invention utilizing such a specific filter.

[0024] According to a further embodiment, preferably, the transformer oil recovery device comprises at least two oil cleaning cartridges. It is noted that using multiple cleaning cartridges provides surprising benefits, easily compensating for even the rare problem—the transformer oil cleaning cartridges providing channels within the bleaching soil, resulting in reduced oil cleaning effectiveness. This modification is surprisingly beneficial since the corresponding problem is believed to be caused by, for example, improper storage or mishandling of the cartridges. Even with a single cartridge providing impaired filtration, it allows for reliable removal of contaminants. It is noted here that this impaired filtration appears to be remedied over time, possibly due to the channels closing during use. This makes it even more advantageous to ensure effective recovery from the outset with this simple solution. For example, it allows for easy local storage of large quantities of the corresponding replacement transformer oil cleaning cartridges. Considering past delivery issues, such as during the COVID-19 pandemic, improving the reliability of the cartridges in this way provides significant benefits, contributing to the overall value of this solution.

[0025] According to a further aspect of the invention, the invention relates to a cabinet as described above.

[0026] According to a further aspect of the invention, the method described above is applicable.

[0027] According to a further embodiment, preferably, before leaving the transformer oil recovery device, if at least one oil drying cylinder is only one oil drying cylinder, the transformer oil finally flows through the oil drying cylinder, or if at least one oil drying cylinder is two or more oil drying cylinders, the transformer oil finally flows through at least one of the at least one drying cylinders.

[0028] Figure 1 A schematic diagram of cabinet 2, containing a transformer oil recovery unit, is shown. This unit is used to recover transformer oil from high-performance transformers used in power grids distributed nationwide. Cabinet 2 includes oil cleaning cylinders 1a and 1b, and an oil drying cylinder 1c. The oil cleaning cylinders 1a and 1b, and the oil drying cylinder 1c, are 120 cm high and 15 cm wide. The oil cleaning cylinder contains bleaching clay, and the oil drying cylinder contains molecular sieves. Pump 4 provides the transformer oil flow through the transformer oil recovery unit. Figure 1 The illustrated embodiment shows a pump based on the flow direction of transformer oil before the oil cleaning cylinders 1a, 1b and the oil drying cylinder 1c.

[0029] Small particles, such as those produced by tearing off paper-like or metal-like materials inside the transformer, are removed from the transformer oil via filter 4. These particles are typically sand-sized. The transformer oil flows through filter 4, as shown in the diagram, typically through a cleaning cartridge 1c and drying cartridges 1a and 1b. This ensures that the oil flowing into the transformer is free of particles.

[0030] After passing through the first transformer oil cleaning cylinder 1a and the second transformer oil cleaning cylinder 1b, the transformer oil enters the transformer oil drying cylinder 1c. Inside the transformer oil drying cylinder 1c, a 3Å molecular sieve is used to remove moisture from the transformer oil. Unless there are irregularities or defects, a constant but low moisture release is typical in this type of transformer. Figure 1 The moisture sensor located after at least one transformer oil drying cylinder is not shown.

[0031] Transformer oil cleaning cartridges 1a and 1b are secured by a cleaning cartridge fastening system, and transformer oil drying cartridge 1c is secured by a drying cartridge fastening system. Here, both the cleaning cartridge fastening system and the drying cartridge fastening system require a wrench to firmly secure the cartridges to the transformer oil recovery device. According to an alternative embodiment of the invention, the cleaning cartridge fastening system and / or the drying cartridge fastening system can be adapted to allow replacement of the transformer oil cleaning cartridge and / or at least one transformer oil drying cartridge without the use of tools.

[0032] The invention has been described in further detail for illustrative purposes only. However, the invention should not be construed as being limited to these embodiments, as they represent embodiments that provide benefits in solving specific problems or meeting specific needs. The scope of protection should be understood to be limited only by the appended claims.

Claims

1. A transformer oil recovery device for recovering transformer oil, comprising: At least one, more preferably at least two oil cleaning cylinders (1a, 1b) and at least one oil drying cylinder (1c). in, The at least one oil cleaning cylinder (1a, 1b) has a height of up to 180 cm and a width of up to 30 cm. The aspect ratio of height to width is at most 12:

1. The at least one oil drying cylinder (1c) has a height of up to 180 cm and a width of up to 30 cm. The aspect ratio of height to width is at most 12:

1. The at least one oil cleaning cylinder (1a, 1b) contains bleaching clay to absorb contaminants from the oil. The at least one oil drying cylinder (1c) contains a molecular sieve to absorb moisture from the oil.

2. The transformer oil recovery device according to any one of the preceding claims, in, The molecular sieve is a 3Å molecular sieve and / or a 4Å molecular sieve.

3. The transformer oil recovery device according to any one of the preceding claims, in, The transformer oil recovery device includes a moisture sensor.

4. The transformer oil recovery device according to any one of the preceding claims, in, The transformer oil recovery device according to any one of the preceding claims The at least one oil cleaning cylinder (1a, 1b) has a height of at least 70 cm measured from the top to the bottom of the oil cleaning cylinder (1a, 1b), and a width of at least 10 cm. The aspect ratio of height to width must be at least 4:

1. The at least one oil drying cylinder (1c) has a height of at least 70 cm measured from the top to the bottom of the oil drying cylinder (1c), and a width of at least 10 cm. The aspect ratio of height to width must be at least 4:

1. The at least one oil cleaning cylinder (1a, 1b) has a height of at least 80 cm and a width of at least 12 cm. The at least one oil drying cylinder (1c) has a height of at least 80 cm and a width of at least 12 cm. More preferably, the at least one oil cleaning cylinder (1a, 1b) has a height of at least 100 cm and a width of at least 15 cm. The at least one oil drying cylinder (1c) has a height of at least 100 cm and a width of at least 15 cm.

5. The transformer oil recovery device according to any one of the preceding claims, in, The aspect ratio of height to width is preferably at least 5:1, and even more preferably at least 6:

1.

6. The transformer oil recovery device according to any one of the preceding claims, in, The transformer oil recovery device according to any one of the preceding claims The at least one oil cleaning cylinder (1a, 1b) has a height of up to 155 cm and a width of up to 24 cm. The at least one oil drying cylinder (1c) has a height of up to 155 cm and a width of up to 24 cm. The aspect ratio of height to width is at most 10:

1. More preferably, the at least one oil cleaning cylinder (1a, 1b) has a height of up to 140 cm and a width of up to 22 cm. The at least one oil drying cylinder (1c) has a height of up to 140 cm and a width of up to 22 cm. The aspect ratio of height to width is at most 9:

1.

7. The transformer oil recovery device according to any one of the preceding claims, in, Based on the fact that the transformer oil recovery device is adapted to allow transformer oil to flow through the device in a specific direction, the transformer oil recovery device provides a transformer oil inlet and a transformer oil outlet. Wherein, if there is only one oil drying cylinder (1c), the oil drying cylinder (1c) is located at the transformer oil outlet; or if there are two or more oil drying cylinders (1c), at least one of the at least one drying cylinders (1c) is located at the transformer oil outlet.

8. The transformer oil recovery device according to any one of the preceding claims, in, Based on the fact that the transformer oil recovery device is adapted to allow transformer oil to flow through the device in a specific direction, the transformer oil recovery device provides a transformer oil inlet and a transformer oil outlet. Wherein, if there is only one oil cleaning cylinder (1a, 1b), the oil cleaning cylinder (1a, 1b) is located at the transformer oil inlet; or if there are two or more oil cleaning cylinders (1a, 1b), at least one of the at least one cleaning cylinders (1a, 1b) is located at the transformer oil inlet.

9. The transformer oil recovery device according to any one of the preceding claims, in, The at least one transformer oil cleaning cylinder (1a, 1b) is secured by a cleaning cylinder (1a, 1b) fastening system, and the at least one transformer oil drying cylinder (1c) is secured by a drying cylinder (1c) fastening system. The cleaning cartridge (1a, 1b) fastening system and / or the drying cartridge (1c) fastening system are adapted to replace at least one cleaning cartridge (1a, 1b) and / or at least one drying cartridge (1c) without the use of tools.

10. The transformer oil recovery device according to any one of the preceding claims, in, The transformer oil recovery device includes at least two oil cleaning cylinders (1a, 1b).

11. The transformer oil recovery device according to any one of the preceding claims, in, The transformer oil recovery device includes a filter (4), which is located before or after the at least one oil cleaning cylinder (1a, 1b) and the at least one other oil drying cylinder (1c), preferably after, based on the flow direction of the transformer oil recovery device being adapted to allow the transformer oil recovery to flow through the transformer oil recovery device.

12. The transformer oil recovery device according to claim 11, wherein, The filter (4) provides a pore size of less than 10 micrometers, more preferably less than 6 micrometers, and even more preferably less than 5 micrometers.

13. A cabinet (2) comprising a transformer oil recovery device according to any one of the preceding claims.

14. A method for recovering transformer oil, wherein, The method utilizes the transformer oil recovery device according to any one of claims 1 to 12 or the cabinet (2) according to claim 13. The method includes the step of removing contaminants from the transformer oil using the at least one oil cleaning cartridge (1a, 1b), and The method includes the step of removing contaminants from the transformer oil using the at least one oil drying cylinder (1c).

15. The method according to claim 14, wherein, Before the transformer oil leaves the transformer oil recovery device, if there is only one oil drying cylinder (1c), the transformer oil will finally flow through the oil drying cylinder (1c), or if there are two or more oil drying cylinders (1c), the transformer oil will finally flow through at least one of the at least one drying cylinders (1c).

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