An online detection device for water and gas content in transformer oil

Abstract

This invention discloses an online detection device for water and gas content in transformer oil, belonging to the field of transformer detection technology. It includes a transformer oil tank with an installation plate at the outer end. The installation plate mounts an oil pump, a pre-filtration unit, and a vortex separation unit. A sensor control unit is mounted on the vortex separation unit, and a hollow probe is located on its inner side. The pre-filtration unit includes a filter container, a coarse filter layer, a fine filter layer, and a pre-separation pressure control plate. The vortex separation unit includes a detection chamber, a conical oil outlet chamber, and a tangential oil inlet pipe. The sensor control unit includes an electromagnet and moisture and gas detection sensors. The hollow probe includes a variable-diameter hollow sleeve, a magnetic piston, and a jet microchannel. Through filtration to remove impurities, active gas separation, and vortex separation concentration, combined with the magnetic piston's active adsorption of gas samples and the purging of sensors, it achieves rapid and accurate online detection of moisture and gas. The device features fast response, high accuracy, and strong stability, meeting the needs of transformer oil trace detection and providing support for safe transformer operation and maintenance.

Description

Technical Field

[0001] This invention relates to the field of transformer testing technology, and more specifically, to an online detection device for the water and gas content in transformer oil. Background Technology

[0002] Transformers are core equipment in power systems, and their operational stability directly affects the safety and reliability of power supply. Transformer oil, as the insulating and cooling medium of the transformer, is crucial to its operating condition. During long-term use, transformer oil is prone to moisture contamination due to factors such as poor sealing and environmental humidity. Simultaneously, organic components in the oil can decompose and produce gases (such as hydrogen and methane) due to aging, or the gas content can abnormally increase due to equipment malfunctions. The presence of moisture severely reduces the insulating performance of the transformer oil, leading to faults such as internal discharge and insulation breakdown. Excessive gas affects the cooling effect of the oil, and the generation of some gases may indicate potential faults such as overheating or partial discharge inside the transformer. If these are not detected and addressed in a timely manner, they may cause serious equipment damage and power accidents.

[0003] Traditional methods for detecting water and gas content in transformer oil have many limitations and cannot meet the needs of intelligent operation and maintenance in power systems. First, while offline detection methods (such as Karl Fischer titration for moisture detection and gas chromatography for gas detection) offer high accuracy, they require manual sampling and delivery to a laboratory for analysis, resulting in long testing cycles. They cannot reflect the true state of the transformer oil in real time, and the sampling process is susceptible to external contamination, affecting the accuracy of the test results. Furthermore, offline detection cannot provide timely warnings for rapid changes in moisture or gas content caused by sudden faults, potentially missing the optimal response time.

[0004] Secondly, existing online detection equipment has significant technical shortcomings. Some online detection devices lack effective impurity filtration and gas extraction structures, allowing impurities in the oil to easily adhere to the sensor surface, leading to decreased detection accuracy and slower response speed. Traditional equipment often relies on natural gas diffusion or infiltration, resulting in low gas extraction efficiency and difficulty in forming stable detection samples. This leads to insufficient sensitivity for detecting trace moisture and gases, and the signal is easily drowned out by noise, failing to meet the requirements for trace detection at the ppm level. Furthermore, moisture and gases are uniformly dispersed in oil, resulting in weak signals when directly detected by the sensor, making accurate quantification difficult. Moreover, after long-term use, the sensor surface is prone to accumulating sludge and colloids, further affecting detection stability and service life.

[0005] To address the aforementioned technical issues, it is necessary to provide an online detection device for the water and gas content in transformer oil. Summary of the Invention

[0006] The purpose of this invention is to provide an online detection device for water and gas content in transformer oil to solve the above-mentioned problems.

[0007] To achieve the above objectives, an embodiment of the present invention provides the following technical solution:

[0008] An online detection device for water and gas content in transformer oil includes a transformer oil tank. A mounting plate is fixedly installed on the outer end of the transformer oil tank. An oil pump is fixedly installed on the upper end of the mounting plate. The oil inlet of the oil pump is connected to the transformer oil tank. An oil outlet pipe is connected to the oil outlet pipe. A pre-filter unit is fixedly installed at the end of the oil outlet pipe away from the oil pump. A vortex separator unit is connected at the end of the pre-filter unit away from the oil outlet pipe, and the lower end of the vortex separator unit is connected to the transformer oil tank. Sensor control units are distributedly installed on the outer end of the vortex separator unit. A hollow probe is fixedly installed at the center of the inner side of the vortex separator unit.

[0009] As a further improvement of the present invention, the pre-filtration unit includes a filter container, on which a coarse filter layer and a fine filter layer are fixedly installed in sequence along the direction close to the vortex separation unit. After filtration by the coarse filter layer and the fine filter layer, impurities in the transformer oil can be intercepted, avoiding interference from impurities in the oil with the detection.

[0010] As a further improvement of the present invention, a pre-separation pressure control plate is fixedly installed at the connection between the filter container and the vortex separation unit. The pre-separation pressure control plate is made of porous material. When the transformer oil passes through the micropores on the pre-separation pressure control plate, a significant throttling effect is generated, forming a local low-pressure zone, which promotes the precipitation of dissolved gas. The huge specific surface area and micropore edges of the pre-separation pressure control plate provide a huge number of nucleation points for bubble nucleation, which greatly promotes the generation efficiency of microbubbles. After passing through the pre-separation pressure control plate, the oil rich in microbubbles is directly injected into the vortex separation chamber at high speed because it is itself confined in the tangential oil inlet pipe. It can actively and efficiently convert dissolved gas into free microbubbles, breaking through the rate limitation of waiting for gas to diffuse / permeate naturally in traditional methods.

[0011] As a further improvement of the present invention, the vortex separation unit includes a vortex separation chamber. A tangential oil inlet pipe is tangentially fixedly installed on the outer surface of the vortex separation chamber and connected to a filter container. A conical oil outlet chamber is fixedly installed at the lower end of the vortex separation chamber. The lower end of the conical oil outlet chamber is connected to the transformer oil tank through a return oil pipe. The vortex separation chamber uses centrifugal force to enrich these dispersed microbubbles into a stable, high-concentration gas nucleus in a short time. This gas nucleus exists stably near the hollow probe, which enables the gas detection sensor to detect samples with significantly amplified concentration and extremely fast updates, resulting in an order-of-magnitude improvement in sensitivity and response speed.

[0012] As a further improvement of the present invention, the sensing control unit includes an electromagnet, a moisture detection sensor, and a gas detection sensor. The electromagnet is fixedly installed at the center of the upper end of the vortex separation chamber. The moisture detection sensor is fixedly installed on the side of the connection between the vortex separation chamber and the conical oil outlet chamber. The gas detection sensor is fixedly installed at the lower end of the electromagnet and located inside the vortex separation chamber. A magnetic shielding sleeve is fixedly installed at the lower end of the electromagnet and is fitted over the gas detection sensor. In the vortex separation chamber, the gas is separated and generates a high-concentration gas nucleus near the hollow probe. The water, which is denser than oil, is thrown towards the inner wall, where it is directly detected by the moisture detection sensor installed on the side wall. With a fixed and repeatable efficiency, the water dispersed in a large amount of oil is collected. The sensor measures this concentrated sample. As long as the concentration ratio is fixed, the sensor reading and the true average value will only differ by a fixed coefficient, regardless of the water content of the incoming oil sample. Traditional online moisture sensors aim to achieve the absolute average value of the water content of every point in the oil tank. This is theoretically perfect, but in practice, it is extremely difficult for trace detection because the signal is too weak and easily drowned out by noise. The present invention, however, amplifies the moisture by focusing it, thereby obtaining the most accurate detection result.

[0013] As a further improvement of the present invention, the hollow probe includes a variable diameter hollow sleeve fixedly installed on the top of the vortex separation chamber, and the variable diameter hollow sleeve is sleeved on the outside of the magnetic shielding sleeve. The upper outer surface of the variable diameter hollow sleeve is provided with a plurality of air intake holes arranged in a ring array, and a waterproof and breathable membrane is fixedly installed in the air intake holes.

[0014] As a further improvement of the present invention, a hollow detection chamber with the same inner diameter at the top and bottom is provided inside the variable diameter hollow sleeve. The outer diameter of the variable diameter hollow sleeve gradually increases from top to bottom in the vertical direction, and the lower surface of the variable diameter hollow sleeve is flush with the connection between the vortex separation chamber and the conical oil outlet chamber. The shape of the hollow probe is characterized by a gradually increasing diameter from top to bottom. Therefore, the oil is more compressed as it goes down. Under the action of centrifugal force, the degree of water accumulation on the inner wall of the vortex separation chamber is higher. At this time, the water detection sensor installed at the boundary between the vortex separation chamber and the conical oil outlet chamber has the highest detection accuracy. At the same time, the gas nucleus at the center can enter the interior of the variable diameter hollow sleeve through the air intake hole and the waterproof and breathable membrane, and then the gas detection sensor can realize gas detection.

[0015] As a further improvement of the present invention, an interference-fit magnetic piston is slidably installed in the hollow detection chamber. A return spring is fixedly installed between the magnetic piston and the bottom wall of the hollow detection chamber. By activating an electromagnet, a repulsive magnetic field is generated against the magnetic piston, causing it to overcome the elastic force of the return spring and move downward. This creates a negative pressure in the upper region, actively adsorbing the gas nuclei on the outside of the variable-diameter hollow sleeve, providing a strong active suction force. This ensures that the gas detection sensor always obtains a sufficient amount of fresh gas sample, unaffected by fluctuations in the mainstream field, resulting in more stable and accurate detection results.

[0016] As a further improvement of the present invention, the magnetic piston includes a piston core, a magnetic base block corresponding to the electromagnet is fixedly installed at the upper end of the piston core, and a wear-resistant sealing ring is fixedly installed at the outer end of the piston core.

[0017] As a further improvement of the present invention, the lower outer surface of the variable-diameter hollow sleeve is provided with multiple annular arrayed jet microchannels. The bottom of the hollow detection chamber is fixedly installed with an annular intercepting net corresponding to the multiple jet microchannels. When the magnetic piston moves downward, the oil below is squeezed out and, after being accelerated by the jet microchannels, is sprayed onto the area of ​​the vortex separation chamber wall facing the moisture detection sensor. This effectively blows away and peels off the sludge, colloids, and air bubbles attached to it, ensuring the detection quality of the moisture detection sensor. After the detection is completed, the magnetic piston is reset under the elastic force of the reset spring, which can discharge the detection gas sample and let it flow away with the oil, avoiding interference with the next detection. At the same time, the oil is re-drawn into the jet microchannels, which can form a suction action in the moisture detection sensor area, sucking away the sludge and other impurities that have just been blown away and peeled off, forming an effect similar to pulsed fluid. Meanwhile, the annular intercepting net can prevent impurities from entering the interior.

[0018] Compared with the prior art, the advantages of this invention are:

[0019] (1) This solution significantly improves the accuracy of trace detection through a concentration and amplification design, solving the problem of weak signals in traditional equipment. Traditional online detection equipment directly detects dispersed moisture and gas, and the signal is easily drowned out by noise. However, this device actively promotes gas precipitation through a pre-separation pressure control plate. The vortex separation chamber uses centrifugal force to concentrate microbubbles into high-concentration gas nuclei and concentrate moisture to the inner wall of the chamber, so that the sensor detects the concentrated sample. The signal intensity is significantly amplified, and even trace moisture and gas at the ppm level can be accurately quantified, and the detection accuracy and sensitivity are improved by orders of magnitude.

[0020] (2) This solution can achieve rapid gas-liquid separation and active detection, significantly improving the response speed. Traditional equipment relies on natural gas diffusion, resulting in low separation efficiency and slow response. However, the pre-separation pressure control plate of this device breaks through the limitations of natural diffusion and quickly generates microbubbles. The vortex separation chamber completes gas-liquid separation and concentration in a short time. Combined with the active adsorption function of the magnetic piston, it ensures that the gas detection sensor can always obtain a sufficient amount of fresh gas sample. The moisture detection sensor directly detects the concentrated sample, greatly improving the overall detection response speed and enabling timely capture of sudden changes in the moisture and gas content in transformer oil.

[0021] (3) This solution has an automatic cleaning and maintenance function to ensure detection stability and equipment lifespan. Traditional equipment sensors are easily affected by impurities and sludge, resulting in poor detection stability. However, the pre-filter unit of this device effectively intercepts impurities and avoids sensor contamination. When the magnetic piston moves down, it sprays oil onto the moisture detection sensor through the jet microchannel to blow away and peel off the surface deposits. When it resets, it sucks away the impurities, forming an automatic cleaning cycle to ensure that the sensor is always in good working condition. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0023] Figure 2 This is a schematic diagram of the pre-filtering unit and the vortex separation unit of the present invention;

[0024] Figure 3 This is a cross-sectional view of the pre-filtering unit of the present invention;

[0025] Figure 4 This is a schematic diagram of the vortex separation unit of the present invention;

[0026] Figure 5 This is a cross-sectional view of the vortex separation unit of the present invention;

[0027] Figure 6 This is a cross-sectional view of the hollow probe in this invention;

[0028] Figure 7 This is a schematic diagram of the structure of the magnetic piston of the present invention.

[0029] Explanation of the labels in the diagram:

[0030] 1. Transformer oil tank; 2. Mounting plate; 3. Oil pump; 4. Pre-filtration unit; 41. Filter container; 42. Coarse filter layer; 43. Fine filter layer; 44. Pre-separation pressure control plate; 5. Vortex separation unit; 51. Vortex separation chamber; 52. Conical oil outlet chamber; 53. Tangential oil inlet pipe; 54. Oil return pipe; 6. Oil outlet pipe; 7. Sensor control unit; 71. Electromagnet; 72. Moisture detection sensor; 73. Gas detection sensor; 74. Magnetic shielding sleeve; 8. Hollow probe; 81. Variable diameter hollow sleeve; 82. Air intake hole; 83. Waterproof and breathable membrane; 84. Magnetic piston; 841. Piston core; 842. Magnetic base block; 843. Wear-resistant sealing ring; 85. Return spring; 86. Jet microchannel; 87. Ring interception net. Detailed Implementation

[0031] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0032] Example 1:

[0033] Please see Figures 1-5 An online detection device for water and gas content in transformer oil includes a transformer oil tank 1. A mounting plate 2 is fixedly installed on the outer end of the transformer oil tank 1. An oil pump 3 is fixedly installed on the upper end of the mounting plate 2. The oil inlet of the oil pump 3 is connected to the transformer oil tank 1. An oil outlet pipe 6 is connected to the oil outlet pipe 3. A pre-filter unit 4 is fixedly installed at the end of the oil outlet pipe 6 away from the oil pump 3. A vortex separation unit 5 is connected at the end of the pre-filter unit 4 away from the oil outlet pipe 6. The lower end of the vortex separation unit 5 is connected to the transformer oil tank 1. Sensor control units 7 are distributedly installed on the outer end of the vortex separation unit 5. A hollow probe 8 is fixedly installed at the center of the inner side of the vortex separation unit 5.

[0034] The pre-filtration unit 4 includes a filter container 41. The filter container 41 is fixedly installed with a coarse filter layer 42 and a fine filter layer 43 in sequence along the direction close to the vortex separation unit 5. After being filtered by the coarse filter layer 42 and the fine filter layer 43, impurities in the transformer oil can be intercepted, avoiding interference from impurities in the oil with the detection.

[0035] The filter container 41 is made of 304 stainless steel through a one-piece molding process, providing good sealing and strong corrosion resistance, protecting the internal filter layer and pre-separation pressure control plate 44 from oil corrosion. Inside the filter container 41, a coarse filter layer 42 and a fine filter layer 43 are fixed sequentially. The coarse filter layer is a stainless steel woven mesh with large openings, capable of intercepting larger impurities in the oil, such as metal fragments and dust particles. The fine filter layer uses a ceramic filter membrane or glass fiber filter material, providing high filtration accuracy and removing tiny suspended solids and colloids from the oil, preventing impurities from adhering to the sensor surface or clogging the flow channels, thus interfering with the detection results.

[0036] A pre-separation pressure control plate 44 is fixedly installed at the connection between the filter container 41 and the vortex separation unit 5. It is made of porous sintered metal material such as stainless steel sintered body. Its interior is full of micropores and has a huge specific surface area. When the transformer oil passes through the micropores on the pre-separation pressure control plate 44, it generates a significant throttling effect, forming a local low-pressure zone, which promotes the precipitation of dissolved gas. The huge specific surface area and micropore edges of the pre-separation pressure control plate 44 provide a huge number of nucleation points for bubble nucleation, which greatly promotes the generation efficiency of microbubbles. After passing through the pre-separation pressure control plate 44, the oil, which is rich in microbubbles, is directly injected into the vortex separation chamber 51 at high speed because it is itself confined in the tangential oil inlet pipe 53. It can actively and efficiently convert dissolved gas into free microbubbles, breaking through the rate limitation of waiting for gas to diffuse / permeate naturally in traditional methods.

[0037] The vortex separation unit 5 includes a vortex separation chamber 51. A tangential oil inlet pipe 53 is tangentially fixed on the upper side of the outer surface of the vortex separation chamber 51 and is connected to the filter container 41. A conical oil outlet chamber 52 is fixedly installed at the lower end of the vortex separation chamber 51. The lower end of the conical oil outlet chamber 52 is connected to the transformer oil tank 1 through a return oil pipe 54. The vortex separation chamber 51 uses centrifugal force to enrich these dispersed microbubbles into a stable, high-concentration gas nucleus in a short time. This gas nucleus exists stably near the hollow probe 8, which enables the gas detection sensor 73 to detect samples with significantly amplified concentration and extremely fast updates, resulting in an order-of-magnitude improvement in sensitivity and response speed.

[0038] The vortex separation chamber 51 is made of 304 stainless steel through spinning, and its inner wall is precision polished to be smooth and burr-free, reducing oil flow resistance and air bubble adhesion. The chamber structure is designed according to fluid mechanics principles, maximizing the use of centrifugal force to improve separation efficiency. A tangential oil inlet pipe 53, made of stainless steel, is fixed tangentially on the outer surface of the vortex separation chamber 51 and seamlessly connected to the pre-filtration unit 4. Oil is injected tangentially into the vortex separation chamber 51 at high speed, forming a strong vortex flow field. A conical oil outlet chamber 52, also made of stainless steel, is fixed at the lower end of the vortex separation chamber 51. The conical structure guides the separated oil smoothly to the return oil pipe 54, while further concentrating any incompletely separated water and impurities, improving detection accuracy.

[0039] The sensing control unit 7 includes an electromagnet 71, a moisture detection sensor 72, and a gas detection sensor 73. The electromagnet 71 is fixedly installed at the center of the upper end of the vortex separation chamber 51. The moisture detection sensor 72 is fixedly installed on the side of the connection between the vortex separation chamber 51 and the conical oil outlet chamber 52. The gas detection sensor 73 is fixedly installed at the lower end of the electromagnet 71 and located inside the vortex separation chamber 51. A magnetic shielding sleeve 74 is fixedly installed at the lower end of the electromagnet 71, and the magnetic shielding sleeve 74 is fitted over the outside of the gas detection sensor 73. In the vortex separation chamber 51, the gas is separated and released into the hollow probe. A high-concentration gas nucleus is generated near needle 8. Water, which is denser than oil, is thrown towards the inner wall, where it is directly detected by the moisture detection sensor 72 installed on the side wall. This allows for consistent and repeatable collection of water dispersed in a large amount of oil. The sensor measures this concentrated sample. As long as the concentration ratio is fixed, regardless of the water content of the incoming oil sample, the sensor reading will differ from the true average value by only a fixed coefficient. Traditional online moisture sensors aim to achieve the absolute average water content at every point in the oil tank. This is theoretically perfect, but in practice, it is extremely difficult to detect trace amounts at the ppm level because the signal is too weak and easily drowned out by noise. This invention, however, amplifies the moisture by focusing it, thus obtaining the most accurate detection result.

[0040] The electromagnet 71 uses electrical pure iron as its core, with high-strength enameled wire wound around it. When energized, it generates a stable repulsive magnetic field, providing precise power to the magnetic piston 84. The magnetic shielding sleeve 74 fixed at the lower end of the electromagnet 71 is made of permalloy, possessing excellent magnetic shielding performance. This prevents the electromagnet's magnetic field from interfering with the operation of the gas detection sensor 73, ensuring a stable detection signal. The moisture detection sensor 72 uses a capacitive or fiber optic moisture sensor. The sensor probe is in direct contact with the oil, and the outer shell is made of stainless steel, making it oil- and corrosion-resistant, and capable of accurately detecting the concentrated moisture content. The gas detection sensor 73 uses an infrared or thermal conductivity gas sensor, offering high sensitivity and fast response, quickly capturing changes in gas concentration within the gas nucleus.

[0041] Example 2:

[0042] Please see Figures 6-7 Based on Example 1, the hollow probe 8 includes a variable diameter hollow sleeve 81 fixedly installed on the top of the vortex separation chamber 51, and the variable diameter hollow sleeve 81 is sleeved on the outside of the magnetic shielding sleeve 74. Multiple air intake holes 82 are arranged in a ring array on the outer surface of the upper end of the variable diameter hollow sleeve 81, and a waterproof and breathable membrane 83 is fixedly installed inside the air intake holes 82.

[0043] The variable-diameter hollow sleeve 81 has a hollow detection chamber with the same inner diameter at the top and bottom. The outer diameter of the variable-diameter hollow sleeve 81 gradually increases from top to bottom in the vertical direction, and the lower surface of the variable-diameter hollow sleeve 81 is flush with the connection between the vortex separation chamber 51 and the conical oil outlet chamber 52. The shape of the hollow probe 8 is characterized by a gradually increasing diameter from top to bottom. Therefore, the oil is more compressed as it goes down. Under the action of centrifugal force, the degree of water accumulation on the inner wall of the vortex separation chamber 51 is higher. At this time, the water detection sensor 72 installed at the boundary between the vortex separation chamber 51 and the conical oil outlet chamber 52 has the highest detection accuracy. At the same time, the gas nucleus at the center can enter the interior of the variable-diameter hollow sleeve 81 through the air intake hole 82 and the waterproof and breathable membrane 83, and then the gas detection sensor 73 can realize gas detection.

[0044] The variable-diameter hollow sleeve 81 of the hollow probe 8 is made of 304 stainless steel through precision machining. Its outer diameter gradually increases from top to bottom vertically. This structure ensures that the oil experiences greater compression force as it descends within the vortex separation chamber 51, leading to a higher degree of water accumulation under centrifugal force, thus providing an optimal detection environment for the moisture detection sensor 72. The air intake hole 82 on the upper outer surface of the variable-diameter hollow sleeve 81 has a uniform pore size. The internally fixed waterproof and breathable membrane 83 is made of polytetrafluoroethylene (PTFE), which has good air permeability and is water-repellent. This allows gas to enter the hollow detection chamber while preventing oil intrusion, protecting the gas detection sensor 73.

[0045] A magnetic piston 84 with an interference fit is slidably installed inside the hollow detection chamber. A return spring 85 is fixedly installed between the magnetic piston 84 and the bottom wall of the hollow detection chamber. By activating the electromagnet 71, a repulsive magnetic field is generated against the magnetic piston 84, causing it to overcome the elastic force of the return spring 85 and move downward. This creates a negative pressure in the upper area, actively adsorbing the gas nuclei on the outside of the variable-diameter hollow sleeve 81, providing a strong active suction force. This ensures that the gas detection sensor 73 always obtains a sufficient amount of fresh gas sample, unaffected by fluctuations in the mainstream field, resulting in more stable and accurate detection results.

[0046] The magnetic piston 84 includes a piston core 841, a magnetic base block 842 corresponding to the electromagnet 71 is fixedly installed on the upper end of the piston core 841, and a wear-resistant sealing ring 843 is fixedly installed on the outer end of the piston core 841.

[0047] The piston core 841 is made of stainless steel, and the magnetic base 842 fixed at its upper end is a neodymium iron boron permanent magnet with high magnetic strength, capable of generating a strong magnetic interaction with the electromagnet 71. The wear-resistant sealing ring 843 fixed at the outer end of the piston core 841 is made of fluororubber, which is oil-resistant, wear-resistant, and has good elasticity, ensuring the sealing performance between the magnetic piston 84 and the wall of the hollow detection chamber, preventing gas leakage or oil seepage. The return spring 85 fixed between the magnetic piston 84 and the bottom wall of the hollow detection chamber is made of stainless steel spring steel, with a stable elastic coefficient, and can quickly drive the magnetic piston to return to its original position after the electromagnet 71 is de-energized.

[0048] Multiple annularly arrayed jet microchannels 86 are formed on the outer surface of the lower end of the variable-diameter hollow sleeve 81. An annular intercepting net 87 corresponding to the multiple jet microchannels 86 is fixedly installed at the bottom of the hollow detection chamber. As the magnetic piston 84 moves downward, the oil below is squeezed out and, after being accelerated by the jet microchannels 86, is sprayed onto the inner wall of the vortex separation chamber 51 in the area facing the moisture detection sensor 72. This effectively blows away and peels off the sludge, colloids, and air bubbles attached to it, ensuring the detection quality of the moisture detection sensor 72. After the detection is completed, the magnetic piston 84 is reset by the elastic force of the return spring 85, which can discharge the detection gas sample and let it flow away with the oil, avoiding interference with the next detection. At the same time, the jet microchannels 86 re-draw oil in, which can form a suction action in the area of ​​the moisture detection sensor 72, sucking away the sludge and other impurities that have just been blown away and peeled off, forming an effect similar to pulsed fluid. Meanwhile, the annular intercepting net 87 can prevent impurities from entering the interior.

[0049] It should be noted that this equipment uses an embedded PLC controller, installed in an independent waterproof and dustproof control box. The control box is made of ABS engineering plastic and has IP54 protection performance, adapting to the complex environment of transformer operation and maintenance sites. The PLC controller establishes electrical connections with oil pump 3, electromagnet 71, moisture detection sensor 72, and gas detection sensor 73 through shielded cables, integrating functions such as oil circulation control, magnetic field drive, signal acquisition, data processing, and result output. It is equipped with an industrial-grade touch screen human-machine interface, allowing operators to intuitively view detection data, set parameters, and monitor equipment operating status.

[0050] In terms of control logic, fully automatic online detection is supported: the controller starts oil pump 3 according to a preset cycle to draw transformer oil into the detection channel; it simultaneously collects real-time signals from moisture detection sensor 72 and gas detection sensor 73. When gas nuclei are detected, the controller drives electromagnet 71 to be energized, generating a repulsive magnetic field that pushes magnetic piston 84 downward, actively attracting gas nuclei and purging moisture detection sensor 72; after detection is completed, the controller controls electromagnet 71 to be de-energized, and magnetic piston 84 is reset under the action of return spring 85, expelling the detected gas sample, and the oil flows back to transformer oil tank 1 through return oil pipe 54. The controller has a built-in data storage and alarm module that can record historical detection data. When the moisture or gas content exceeds the preset threshold, it will promptly issue an audible and visual alarm to remind staff to handle the situation.

[0051] Working principle:

[0052] When in use, first fix the equipment to the outside of the transformer oil tank 1 using the mounting plate 2, ensure that all pipe connections are sealed and leak-free, connect the power supply and start the detection program through the touch screen.

[0053] After the detection is initiated, the PLC controller starts the oil pump 3, which draws transformer oil from the transformer oil tank 1. The oil is then transported to the pre-filtration unit 4 via the oil outlet pipe 6. First, it passes through the coarse filter layer 42 to intercept larger impurities, and then through the fine filter layer 43 to remove tiny suspended solids and colloids, preventing impurities from interfering with subsequent separation and detection. The filtered oil flows through the pre-separation pressure control plate 44, where its porous structure creates a throttling effect, forming a local low-pressure zone. This promotes the rapid release of dissolved gases from the oil, while the micropore edges provide numerous nucleation sites, accelerating the generation of microbubbles and transforming the oil into a microbubble-rich mixture.

[0054] Oil rich in microbubbles is injected tangentially into the vortex separation chamber 51 at high speed through the tangential oil inlet pipe 53, forming a strong vortex flow field within the chamber. Under the action of centrifugal force, microbubbles with a density much smaller than that of the oil are rapidly aggregated to the central region of the chamber, quickly becoming rich into stable, high-concentration gas nuclei, which remain stably near the hollow probe 8. Meanwhile, water with a density greater than that of the oil is thrown towards the inner wall of the vortex separation chamber 51, where it concentrates and accumulates at the connection between the chamber and the conical oil outlet chamber 52, providing a high-concentration detection sample for the moisture detection sensor 72.

[0055] Simultaneously, the PLC controller drives the electromagnet 71 to be energized, generating a repulsive magnetic field that acts on the magnetic base block 842 of the magnetic piston 84, causing the magnetic piston to move downwards against the elastic force of the return spring 85. During the downward movement of the magnetic piston, a negative pressure is formed in the upper part of the hollow detection chamber, which actively attracts the gas nucleus in the center of the chamber through the air intake hole 82 at the upper end of the variable diameter hollow sleeve 81. The gas enters the hollow detection chamber through the waterproof and breathable membrane 83, and the gas content is quickly detected by the gas detection sensor 73. At the same time, the downward movement of the magnetic piston squeezes the oil below. After being accelerated by the jet microchannel 86, the oil is sprayed onto the inner wall of the vortex separation chamber 51 in the area directly opposite the moisture detection sensor 72, blowing away and peeling off the sludge, colloids and air bubbles attached to the sensor surface, ensuring that the moisture detection sensor can accurately detect the concentrated moisture content.

[0056] After the test is completed, the PLC controller de-energizes the electromagnet 71, and the magnetic piston 84 returns to its original position under the elastic force of the return spring 85, expelling the gas sample from the hollow test chamber, which flows along with the oil. During the reset process, a suction action is generated at the jet microchannel 86, sucking away the impurities blown down. The annular interceptor net 87 intercepts the impurities, preventing them from entering the hollow test chamber. The transformer oil, after separating the moisture and gas, flows through the conical oil outlet chamber 52 into the return oil pipe 54, and finally returns to the transformer oil tank 1, completing one test cycle.

[0057] Throughout the testing process, the PLC controller collects signals from the moisture detection sensor 72 and the gas detection sensor 73 in real time. The built-in algorithm is used to calculate the actual moisture and gas content in the transformer oil. The test results are displayed on the touch screen and stored in the device's memory. If the detected value exceeds the preset threshold, the device immediately issues an audible and visual alarm to remind staff to treat the transformer oil in a timely manner to ensure the safe operation of the transformer.

[0058] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and not restrictive.

[0059] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style of the specification is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. An online detection device for water and gas content in transformer oil, comprising a transformer oil tank (1), characterized in that: An installation plate (2) is fixedly installed on the outer end of the transformer oil tank (1). An oil pump (3) is fixedly installed on the upper end of the installation plate (2). The oil inlet of the oil pump (3) is connected to the transformer oil tank (1). An oil outlet pipe (6) is connected to the oil outlet of the oil pump (3). A pre-filter unit (4) is fixedly installed on the end of the oil outlet pipe (6) away from the oil pump (3). The pre-filter unit (4) is connected to a vortex separation unit (5) at the end away from the oil outlet pipe (6), and the lower end of the vortex separation unit (5) is connected to the transformer oil tank (1). A sensor control unit (7) is distributedly installed at the outer end of the vortex separation unit (5), and a hollow probe (8) is fixedly installed at the center of the inner side of the vortex separation unit (5). The pre-filtration unit (4) includes a filter container (41), on which a coarse filter layer (42) and a fine filter layer (43) are fixedly installed in sequence along the direction close to the vortex separation unit (5). A pre-separation pressure control plate (44) is fixedly installed at the connection between the filter container (41) and the vortex separation unit (5). The pre-separation pressure control plate (44) is made of porous material and is used to quickly generate microbubbles.

2. The online detection device for water and gas content in transformer oil according to claim 1, characterized in that: The vortex separation unit (5) includes a vortex separation chamber (51). A tangential oil inlet pipe (53) is tangentially fixedly installed on the outer surface of the vortex separation chamber (51), and the tangential oil inlet pipe (53) is connected to the filter container (41). A conical oil outlet chamber (52) is fixedly installed at the lower end of the vortex separation chamber (51), and the lower end of the conical oil outlet chamber (52) is connected to the transformer oil tank (1) through a return oil pipe (54).

3. The online detection device for water and gas content in transformer oil according to claim 2, characterized in that: The sensing control unit (7) includes an electromagnet (71), a moisture detection sensor (72), and a gas detection sensor (73). The electromagnet (71) is fixedly installed at the center of the upper end of the vortex separation chamber (51). The moisture detection sensor (72) is fixedly installed on the side of the connection between the vortex separation chamber (51) and the conical oil outlet chamber (52). The gas detection sensor (73) is fixedly installed at the lower end of the electromagnet (71) and located inside the vortex separation chamber (51). A magnetic shielding sleeve (74) is fixedly installed at the lower end of the electromagnet (71), and the magnetic shielding sleeve (74) is sleeved on the outside of the gas detection sensor (73).

4. The online detection device for water and gas content in transformer oil according to claim 3, characterized in that: The hollow probe (8) includes a variable diameter hollow sleeve (81) fixedly installed on the top of the vortex separation chamber (51), and the variable diameter hollow sleeve (81) is sleeved on the outside of the magnetic shielding sleeve (74). Multiple air intake holes (82) are arranged in a ring array on the outer surface of the upper end of the variable diameter hollow sleeve (81), and a waterproof and breathable membrane (83) is fixedly installed in the air intake hole (82).

5. The online detection device for water and gas content in transformer oil according to claim 4, characterized in that: The variable-diameter hollow sleeve (81) has a hollow detection chamber with the same inner diameter at the top and bottom. The outer diameter of the variable-diameter hollow sleeve (81) gradually increases from top to bottom in the vertical direction, and the lower surface of the variable-diameter hollow sleeve (81) is flush with the connection between the vortex separation chamber (51) and the conical oil outlet chamber (52).

6. The online detection device for water and gas content in transformer oil according to claim 5, characterized in that: A magnetic piston (84) with interference fit is slidably installed in the hollow detection chamber, and a return spring (85) is fixedly installed between the magnetic piston (84) and the bottom wall of the hollow detection chamber.

7. The online detection device for water and gas content in transformer oil according to claim 6, characterized in that: The magnetic piston (84) includes a piston core (841), a magnetic base block (842) corresponding to the electromagnet (71) is fixedly installed on the upper end of the piston core (841), and a wear-resistant sealing ring (843) is fixedly installed on the outer end of the piston core (841).

8. The online detection device for water and gas content in transformer oil according to claim 7, characterized in that: The lower outer surface of the variable diameter hollow sleeve (81) is provided with multiple annular array-distributed jet microchannels (86), and the bottom of the hollow detection chamber is fixedly installed with an annular interception net (87) corresponding to the multiple jet microchannels (86).

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