A defoaming device for measuring low temperature electrical performance of plant insulating oil

Abstract

The application relates to the technical field of power equipment insulation medium detection, in particular to a defoaming device for measuring the low-temperature electrical performance of plant insulating oil, which comprises an insulating rod, an insulating disc, a bubble guide column, an oil-repellent bubble collecting plate and a PTFE mesh cover, a first through hole is arranged in the center of the PTFE mesh cover, a second through hole is arranged in the center of the oil-repellent bubble collecting plate, a third through hole is arranged in the center of the insulating disc, the insulating rod passes through the first through hole, the second through hole and the third through hole in sequence and is fixedly connected with the PTFE mesh cover, the oil-repellent bubble collecting plate and the insulating disc respectively, a plurality of bubble guide holes are arranged on the insulating disc, one bubble guide column is arranged on each bubble guide hole, one end of the bubble guide column close to the insulating disc is fixedly connected with the insulating disc, and one end of the bubble guide column close to the oil-repellent bubble collecting plate is abutted against the oil-repellent bubble collecting plate. The application has the effects of eliminating bubbles and stabilizing the measured value.

Description

Technical Field

[0001] This application relates to the field of electrical equipment insulation medium testing technology, specifically to a special device for eliminating air bubbles in vegetable insulating oil during electrical performance testing in low-temperature environments, thereby ensuring the accuracy of test data. Background Technology

[0002] Plant-based insulating oils (such as natural ester-based insulating oils) are a novel environmentally friendly medium with good biodegradability and a high flash point, showing broad application prospects in transformers and power equipment. However, under low-temperature conditions, the viscosity of plant-based insulating oils increases significantly, making it difficult for dissolved gases and microbubbles to escape. These gases tend to accumulate in the oil-paper insulation system, thus significantly interfering with electrical performance test results such as partial discharge measurements and breakdown voltage tests. Existing defoaming methods mostly rely on vacuum treatment or long-term static placement, but these methods are inefficient and cannot meet the requirements of real-time electrical performance measurements at low temperatures. Therefore, there is an urgent need for a device that can efficiently eliminate bubbles during low-temperature measurements to ensure the reliability of electrical performance measurements of plant-based insulating oils. Utility Model Content

[0003] To reduce bubble interference and stabilize measurement values, this application provides a defoaming device for measuring the low-temperature electrical properties of plant insulating oil.

[0004] The defoaming device for measuring the low-temperature electrical properties of vegetable insulating oil provided in this application adopts the following technical solution:

[0005] A defoaming device for measuring the low-temperature electrical properties of plant insulating oil includes an insulating rod, an insulating disc, bubble guide columns, an oleophobic bubble collection plate, and a PTFE mesh cover. The PTFE mesh cover has a first through hole in its center, the oleophobic bubble collection plate has a second through hole in its center, and the insulating disc has a third through hole in its center. The insulating rod passes through the first through hole, the second through hole, and the third through hole in sequence, and is fixedly connected to the PTFE mesh cover, the oleophobic bubble collection plate, and the insulating disc, respectively. The insulating disc has a plurality of bubble guide holes, and a bubble guide column is correspondingly provided on each bubble guide hole. The end of the bubble guide column near the insulating disc is fixedly connected to the insulating disc, and the end of the bubble guide column near the oleophobic bubble collection plate abuts against the oleophobic bubble collection plate.

[0006] By adopting the above technical solution, the insulating rod is sequentially fixedly connected to the PTFE mesh cover, the oleophobic bubble collection plate, and the insulating disk. Several bubble-guiding columns are distributed on the insulating disk and connected to the bubble-guiding holes. Under low-temperature conditions, the insulating rod is inserted into the oil, and the insulating disk contacts the liquid surface. Tiny bubbles in the oil enter the bubble-guiding columns along the bubble-guiding holes and rise to the oleophobic bubble collection plate under buoyancy. Guided by the oleophobic bubble collection plate, they gradually coalesce into larger bubbles and escape rapidly through the PTFE mesh cover, preventing bubbles from remaining in the oil-paper insulation system. The entire defoaming process can usually be completed within 10-15 minutes, significantly shortening the time required for traditional static or vacuum defoaming. No additional vacuum equipment or long static treatment is needed to achieve efficient defoaming of oil under low-temperature conditions. After defoaming, the vegetable insulating oil is subjected to low-temperature breakdown voltage testing, dielectric loss factor measurement, and conductivity testing, improving the accuracy and reliability of electrical performance testing.

[0007] Optionally, a sleeve is provided on the side of the third through hole facing the oleophobic bubble collection plate. The sleeve is fixedly connected to the insulating disc. An internal thread is provided inside the sleeve. An external thread is provided at one end of the insulating rod near the sleeve. The insulating rod passes through the sleeve and is threadedly connected to the sleeve.

[0008] By adopting the above technical solution, a sleeve is fixedly installed in the center of the insulating disk, and the sleeve is threadedly connected to the insulating rod. This not only achieves the fixing of the insulating disk on the insulating rod, but also facilitates the disassembly of the insulating disk. The insulating disk and the several bubble guide columns installed on the insulating disk can be cleaned at any time to prevent the bubble guide columns from becoming clogged.

[0009] Optionally, a protective shell is provided around the periphery of several of the bubble-guiding columns, the lower end of the protective shell is snapped into the insulating disc, and the upper end of the protective shell abuts against the oleophobic bubble-collecting plate.

[0010] By adopting the above technical solution, a protective shell is set around the bubble guide column, which can effectively protect the bubble guide column from external collision and wear, and can also effectively prevent oil from entering the gap between several bubble guide columns and causing equipment contamination. The lower end of the protective shell is snapped into the insulating disc, which not only fixes the protective shell to the insulating disc, but also makes the protective shell easy to disassemble, saving time and effort.

[0011] Optionally, the diameter of the insulating disc is larger than the diameter of the PTFE mesh cover.

[0012] By adopting the above technical solution, the diameter of the insulating disk is larger than the diameter of the PTFE mesh cover, which not only provides space for the inclined setting of several bubble-guiding columns, but also increases the area of ​​the insulating disk, allowing the insulating disk to cover more liquid surface, thereby increasing the bubble-guiding area and improving measurement accuracy.

[0013] Optionally, all of the bubble guide columns are inclined toward the center of the insulating disk, with an inclination angle between 30° and 60°.

[0014] By adopting the above technical solution, the bubble guide column is set at an angle, and the buoyancy difference is used to make the bubbles float. This also balances the flow rate and the bubble residence time, which can effectively improve the bubble separation efficiency.

[0015] Optionally, a tapered transition section is provided at the end of the bubble guide column near the oleophobic bubble collection plate.

[0016] By adopting the above technical solution, a conical transition section is set at the end of the bubble guide column to narrow the flow channel and improve the bubble aggregation efficiency, thus preparing it for entry into the PTFE mesh cover.

[0017] Optionally, a fixing cylinder is provided in the first through hole. The outer ring of the fixing cylinder is fixedly connected to the PTFE mesh cover. The inner ring of the fixing cylinder has an internal thread, and the insulating rod has a corresponding external thread. The fixing cylinder is sleeved on the insulating rod and threadedly connected to the insulating rod.

[0018] By adopting the above technical solution, the outer ring of the fixing cylinder is fixedly connected to the PTFE mesh cover, and the inner ring of the fixing cylinder is threadedly connected to the insulating rod, thereby realizing the fixing of the PTFE mesh cover on the insulating rod and facilitating disassembly or replacement.

[0019] In summary, this application includes at least one of the following beneficial technical effects:

[0020] 1. By sequentially fixing the insulating rod to the PTFE mesh cover, the oleophobic bubble collection plate, and the insulating disc, several bubble guide columns are distributed on the insulating disc and connected to the bubble guide holes. Under low temperature conditions, the insulating rod is inserted into the oil, and the insulating disc contacts the liquid surface. Tiny bubbles in the oil enter the bubble guide columns along the bubble guide holes and rise to the oleophobic bubble collection plate under the action of buoyancy. Under the guidance of the oleophobic bubble collection plate, they gradually coalesce into larger bubbles and escape quickly through the PTFE mesh cover, avoiding the bubbles from being trapped in the oil-paper insulation system, thereby improving the accuracy and reliability of electrical performance testing.

[0021] 2. By fixing a sleeve at the center of the insulating disc and connecting the sleeve to the insulating rod with threads, the insulating disc is fixed on the insulating rod, which also facilitates the disassembly of the insulating disc. The insulating disc and the several bubble guide columns set on the insulating disc can be cleaned at any time to prevent the bubble guide columns from becoming clogged.

[0022] 3. By tilting the bubble guide column, the buoyancy difference is used to make the bubbles rise, which can also balance the flow rate and the bubble residence time, thus effectively improving the bubble separation efficiency. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of a defoaming device for measuring the low-temperature electrical properties of plant-based insulating oil, as described in this application.

[0024] Figure 2 This is a partial structural schematic diagram of a defoaming device for measuring the low-temperature electrical properties of plant-based insulating oil, as described in this application.

[0025] Figure 3 This is a schematic diagram of the insulating rod in this application.

[0026] Figure 4 This is a schematic diagram of the structure of the insulating disk and protective shell in this application.

[0027] Explanation of reference numerals in the attached drawings: 1. Insulating rod; 11. External thread one; 12. External thread two; 2. Insulating disc; 21. Third through hole; 22. Bubble guide hole; 23. Slot; 3. Bubble guide column; 4. Oil-repellent bubble collection plate; 41. Second through hole; 5. PTFE mesh cover; 51. First through hole; 6. Sleeve; 61. Internal thread one; 7. Protective shell; 8. Fixing cylinder; 81. Internal thread two. Detailed Implementation

[0028] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail.

[0029] This application discloses a defoaming device for measuring the low-temperature electrical properties of vegetable insulating oil.

[0030] Reference Figure 1 A defoaming device for measuring the low-temperature electrical properties of plant insulating oil includes an insulating rod 1, an insulating disc 2, a bubble-guiding column 3, an oleophobic bubble-collecting plate 4, and a PTFE mesh cover 5. The PTFE mesh cover 5, the oleophobic bubble-collecting plate 4, the bubble-guiding column 3, and the insulating disc 2 are arranged sequentially from top to bottom. The PTFE mesh cover 5 has a first through hole 51 in its center, the oleophobic bubble-collecting plate 4 has a second through hole 41 in its center, and the insulating disc 2 has a third through hole 21 in its center. The insulating rod 1 passes through the first through hole 51, the second through hole 41, and the third through hole 21 in sequence, and is fixedly connected to the PTFE mesh cover 5, the oleophobic bubble-collecting plate 4, and the insulating disc 2, respectively. The insulating disc 2 has a plurality of bubble-guiding holes 22, and a bubble-guiding column 3 is correspondingly arranged on each bubble-guiding hole 22. The end of the bubble-guiding column 3 near the insulating disc 2 is fixedly connected to the insulating disc 2, and the end of the bubble-guiding column 3 near the oleophobic bubble-collecting plate 4 abuts against the oleophobic bubble-collecting plate 4.

[0031] In this application, a standard transformer oil test clamp is selected as the insulating rod 1 in the low-temperature electrical performance measurement device. The insulating rod 1 in this application is made of engineering plastic or ceramic material that is resistant to low temperature and has high insulation strength, so as to ensure structural stability and no thermal shrinkage under low temperature conditions.

[0032] The PTFE mesh cover 5 has a pore size of 50-200μm. The PTFE mesh cover 5 has both oleophobic and breathable properties, which allows microbubbles to coalesce and release in a short time, reducing interference with electrical measurement results.

[0033] The oleophobic bubble collection plate 4 is made of a material with low surface energy and chemical inertness. In this application, PTFE or modified polytetrafluoroethylene is preferred.

[0034] This application utilizes a combined structure of insulating rod 1, insulating disc 2, bubble guiding column 3, oleophobic bubble collecting plate 4, and PTFE mesh cover 5 to achieve efficient migration, coalescence, and escape of bubbles. This effectively eliminates the influence of residual bubbles in the oil on electrical performance test results such as partial discharge measurement, breakdown voltage test, and dielectric loss factor measurement, thereby providing a stable and reliable testing technology guarantee for the low-temperature performance evaluation of plant insulating oil and related power equipment.

[0035] Reference Figure 2 , 3 A sleeve 6 is provided on the side of the third through hole 21 facing the oleophobic bubble collection plate 4. The bottom of the sleeve 6 is fixedly connected to the insulating disc 2. An internal thread 61 is provided inside the sleeve 6. An external thread 11 is provided on the end of the insulating rod 1 near the sleeve 6. The insulating rod 1 passes through the sleeve 6 and is threadedly connected to the sleeve 6, thereby fixing the insulating disc 2 on the insulating rod 1.

[0036] To increase the bubble-conducting area, the diameter of the insulating disk 2 is larger than the diameter of the PTFE mesh cover 5, so that the small bubbles around the insulating rod 1 can be covered and collected.

[0037] Several bubble-guiding columns 3 are inclined towards the center of the insulating disk 2, with an inclination angle between 30° and 60°. The diameter of the bubble-guiding columns 3 is controlled between 30 and 80 μm to ensure smooth bubble migration even when the oil viscosity is high at low temperatures. In addition, the inner surface of the bubble-guiding columns 3 has a smooth structure to reduce resistance during bubble migration.

[0038] In addition, the end of the bubble guide column 3 near the oleophobic bubble collecting plate 4 is set as a conical transition section, which can shrink the flow channel to improve the bubble collection efficiency.

[0039] Reference Figure 2 and Figure 3 A fixing cylinder 8 is provided in the first through hole 51. The upper part of the outer ring of the fixing cylinder 8 is fixedly connected to the top of the PTFE mesh cover 5, and the lower part of the outer ring of the fixing cylinder 8 is fixedly connected to the bottom of the PTFE mesh cover 5. The inner ring of the fixing cylinder 8 is provided with an internal thread 81, and the insulating rod 1 is provided with an external thread 12. The fixing cylinder 8 is sleeved on the insulating rod 1 and threadedly connected to the insulating rod 1.

[0040] Reference Figure 4 A protective shell 7 is provided around several bubble guide columns 3 to effectively prevent oil from entering the gaps between the bubble guide columns 3. The insulating disk 2 faces the oleophobic bubble collection plate 4, and a slot 23 is opened around the circumference of the insulating disk 2. The lower end of the protective shell 7 is inserted into the slot 23 to achieve a snap-fit ​​with the insulating disk 2, and the upper end of the protective shell 7 abuts against the oleophobic bubble collection plate 4.

[0041] The device described in this application is not only suitable for measuring the low-temperature electrical properties of vegetable insulating oils, but can also be extended to electrical testing scenarios for natural esters and high-viscosity synthetic insulating oils. It can maintain good defoaming effect under different oil types and low-temperature conditions, and has strong versatility and applicability. It is of great significance for improving the reliability and efficiency of insulation testing of power equipment.

[0042] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A defoaming device for measuring the low-temperature electrical properties of plant-based insulating oil, characterized in that: The device includes an insulating rod (1), an insulating disc (2), a bubble guide column (3), an oleophobic bubble collection plate (4), and a PTFE mesh cover (5). The PTFE mesh cover (5) has a first through hole (51) in the center, the oleophobic bubble collection plate (4) has a second through hole (41) in the center, and the insulating disc (2) has a third through hole (21) in the center. The insulating rod (1) passes through the first through hole (51), the second through hole (41), and the third through hole (21) in sequence, and is fixedly connected to the PTFE mesh cover (5), the oleophobic bubble collection plate (4), and the insulating disc (2) respectively. The insulating disc (2) has several bubble guide holes (22), and each bubble guide hole (22) is provided with a corresponding bubble guide column (3). The bubble guide column (3) is fixedly connected to the insulating disc (2) at one end near the insulating disc (2), and the bubble guide column (3) abuts against the oleophobic bubble collection plate (4) at one end near the oleophobic bubble collection plate (4).

2. The defoaming device for measuring the low-temperature electrical properties of plant-based insulating oil according to claim 1, characterized in that: The third through hole (21) is provided with a sleeve (6) facing the oleophobic bubble collection plate (4). The sleeve (6) is fixedly connected to the insulating disc (2). The sleeve (6) has an internal thread (61). The insulating rod (1) has an external thread (11) at one end near the sleeve (6). The insulating rod (1) passes through the sleeve (6) and is threadedly connected to the sleeve (6).

3. The defoaming device for measuring the low-temperature electrical properties of plant-based insulating oil according to claim 1, characterized in that: A protective shell (7) is provided around several of the bubble guide columns (3). The lower end of the protective shell (7) is snapped into the insulating disk (2), and the upper end of the protective shell (7) abuts against the oleophobic bubble collection plate (4).

4. The defoaming device for measuring the low-temperature electrical properties of vegetable insulating oil according to claim 1, characterized in that: The diameter of the insulating disk (2) is larger than the diameter of the PTFE mesh cover (5).

5. The defoaming device for measuring the low-temperature electrical properties of vegetable insulating oil according to claim 4, characterized in that: Several of the bubble guide columns (3) are inclined toward the center of the insulating disk (2), with an inclination angle between 30° and 60°.

6. The defoaming device for measuring the low-temperature electrical properties of plant-based insulating oil according to claim 5, characterized in that: The bubble guide column (3) has a tapered transition section at one end near the oleophobic bubble collection plate (4).

7. The defoaming device for measuring the low-temperature electrical properties of vegetable insulating oil according to claim 1, characterized in that: A fixing cylinder (8) is provided in the first through hole (51). The outer ring of the fixing cylinder (8) is fixedly connected to the PTFE mesh cover (5). The inner ring of the fixing cylinder (8) is provided with an internal thread (81). The insulating rod (1) is provided with an external thread (12). The fixing cylinder (8) is sleeved on the insulating rod (1) and threadedly connected to the insulating rod (1).

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