Solid particle detection and analysis system and method in transformer insulating oil

Abstract

The present invention provides a solid particle detection and analysis system and method in transformer insulating oil, comprising a filtering device, the filtering device comprising a housing and a cover, an upper partition plate is arranged in the housing, a mounting through hole is arranged on the upper partition plate, a funnel is arranged in the mounting through hole, a sample bottle positioning ring is arranged on the upper part of the funnel, a top column is arranged at the center of the sample bottle positioning ring, a sample bottle is installed in the sample bottle positioning ring, the sample bottle comprises a bottle body and a bottom cover connected to the bottom of the bottle body, a liquid leakage channel is arranged on the bottom cover, an elastic mechanical switch assembly is arranged at the liquid leakage channel, a handle is arranged below the funnel, the handle comprises an upper boss, a middle flange and a lower boss, the upper boss is used to place a filter membrane, and the lower boss is used to connect a vacuum bottle. The present invention has the advantages of high efficiency and high automation in sample pre-treatment, and can quickly detect the composition and microscopic morphology of particles in insulating oil, helping staff to quickly determine the source of particle pollutants.

Description

Technical Field

[0001] The present invention mainly relates to the technical field related to transformer maintenance, and specifically relates to a system and method for detecting and analyzing solid particles in insulating oil. Background Art

[0002] The insulating oil in the transformer is made from natural petroleum through distillation and refining. It has the advantages of low viscosity, good insulation and cooling properties. The composition of insulating oil is complex, and its main components are compounds such as alkanes, cycloalkanes and aromatic hydrocarbons. It has a high dielectric breakdown voltage and plays a major role in heat dissipation, insulation protection and arc extinguishing during the operation of equipment such as transformers, reactors or mutual inductors. The quality of insulating oil is directly related to the safe and stable operation of the equipment.

[0003] Impurity particles in insulating oil refer to the granular substances that invade the oil and are insoluble in the oil, also known as particle contamination, which are mainly fiber, carbon and various metal impurity particles. There are mainly the following forms: inherent impurity particles, medium pollution, impurities generated during the operation of the transformer, etc.

[0004] Under the action of non-uniform electric field, these contaminant particles are affected by the dielectrophoretic force and move toward the high electric field area, and can form small solid particle bridges for a period of time, which will greatly affect the electrical properties of the insulating oil. Therefore, in order to ensure the stable operation of equipment such as transformers, reactors or mutual inductors, it is necessary to detect the impurity particle contaminants in the insulating oil.

[0005] At present, particulate pollutants in insulating oil are mainly detected by inductively coupled plasma atomic emission spectroscopy and atomic absorption spectroscopy. These two methods can only measure the content of metal elements, but not non-metallic elements, and cannot know the specific composition and microscopic morphology of particulate pollutants. In addition, the pretreatment of the test sample requires filtering the particles in the insulating oil. Traditionally, this method is mostly manual, using a funnel and a filter membrane, which is inefficient and the process is cumbersome. Summary of the invention

[0006] In order to solve the shortcomings of the current technology, the present invention combines the existing technology and provides a solid particle detection and analysis system and method in insulating oil from the perspective of practical application. The system and method have the advantages of high efficiency and high degree of automation in sample pretreatment, and can quickly detect the composition and microscopic morphology of particles in insulating oil, helping staff to quickly determine the source of particulate pollutants.

[0007] The technical solution of the present invention is as follows:

[0008] According to one aspect of the present invention, a solid particle detection and analysis system in transformer insulating oil is provided, comprising a filtering device, the filtering device comprising a housing and a cover body that can be flipped open, an upper partition is arranged in the housing, a mounting through hole is arranged on the upper partition, a funnel is arranged in the mounting through hole, the funnel is connected to the partition by an elastic mechanical support component so that the funnel can move up and down and reset;

[0009] A sample bottle positioning ring is arranged on the upper part of the funnel, a top column is arranged at the center of the sample bottle positioning ring, a sample bottle is installed in the sample bottle positioning ring, the sample bottle comprises a bottle body and a bottom cover connected to the bottom of the bottle body, a liquid leakage channel is arranged on the bottom cover, an elastic mechanical switch assembly is arranged at the liquid leakage channel, and the elastic mechanical switch assembly enables the liquid leakage channel to be opened under the action of the top column when the sample bottle moves downward;

[0010] A handle is provided below the funnel, and the handle includes an upper boss, a middle flange and a lower boss. The upper boss is used to place the filter membrane, and the lower boss is used to connect the vacuum bottle. A vacuum channel is provided on the handle, and the vacuum channel is connected to a vacuum source provided in the housing.

[0011] The cover body is connected to a lifting mechanism, and a pressure head is provided on the cover body. A stirring shaft is installed on the pressure head, and the stirring shaft is connected to a stirring motor. When the cover body is closed, the position of the pressure head corresponds to the vacuum bottle. When the lifting mechanism drives the cover body to move downward, the pressure head applies force to the sample bottle, so that the sample bottle opens and connects with the funnel, and at the same time, the funnel moves downward and cooperates with the upper boss to clamp and fix the filter membrane. When the lifting mechanism is reset, the sample bottle and the funnel are reset accordingly.

[0012] Furthermore, a groove is provided at the bottom of the bottom cover, and the elastic mechanical switch assembly includes a plug for blocking the leakage channel, a driving block is connected in the middle of the bottom of the plug, a first connecting rod is provided on both sides of the driving block, a first guide rod is fixedly provided in the groove, the first connecting rod is slidably matched with the first guide rod, and a first spring is provided on the first guide rod to apply force to the first connecting rod downward, and the driving block and the first connecting rod are both located in the groove.

[0013] Furthermore, the elastic mechanical support assembly includes a flange and a second guide rod; the flange is fixedly connected to the funnel body, one end of the second guide rod is fixedly connected to the flange, and the other end is slidably matched with a guide hole provided on the upper partition, and a second spring is provided on the second guide rod to apply force to the flange upward.

[0014] Furthermore, the top column is supported by a plurality of second connecting rods fixed to the inner wall of the funnel.

[0015] Furthermore, sealing rings are provided on the top surface of the upper boss and the bottom surface of the funnel.

[0016] Furthermore, a liquid tank and a pressure pump are also provided in the housing, and the liquid tank is used to store the flushing liquid;

[0017] A plurality of nozzles are also arranged on the pressure head, and the nozzles are connected to the liquid tank through a hose;

[0018] A liquid discharge channel is arranged at the bottom of the vacuum bottle, and a liquid discharge valve is arranged on the liquid discharge channel.

[0019] Furthermore, one end opening of the vacuum channel is arranged on the bottom surface of the lower boss, and the other end opening is arranged on the middle flange. A pipeline is installed at the middle flange to connect to the vacuum source, and a tee and an air inlet valve are arranged on the pipeline.

[0020] Furthermore, the filtering device further comprises a filter membrane holder, the filter membrane holder comprising a handheld plate and clamping arms on both sides, and a supporting groove for placing the filter membrane is provided on the clamping arms;

[0021] A sliding groove for sliding the filter membrane frame is arranged on one side of the shell, and after the filter membrane is installed on the filter membrane frame, it can be pushed to the upper boss by the sliding groove.

[0022] Furthermore, it also includes a microscopic imager, which is used to analyze the particles filtered on the filter membrane.

[0023] According to another aspect of the present invention, a method for detecting and analyzing solid particles in transformer insulating oil is provided, comprising the following steps:

[0024] S1. Filter the quantitative insulating oil through the filtering equipment of the above-mentioned detection and analysis system, separate the solid particles in the insulating oil to the filter membrane, and move the filter membrane to the watch glass;

[0025] S2. Use a microanalyzer to count the number of particles, particle size, and the number of pixels contained in the quantitative oil products, calculate the equivalent area circle and equivalent spherical volume of each particle, and thus obtain the equivalent area diameter and equivalent spherical volume diameter of the particle and the circularity parameter. Then, perform graded statistics on all particles to obtain the particle size distribution and circularity distribution information, and determine the actual composition of the particulate pollutants based on the analysis information.

[0026] Beneficial effects of the present invention:

[0027] 1. In the solid particle detection and analysis system of the present invention, the design of the filtering equipment has a high degree of automation. In actual use, the operator only needs to place the filter membrane in a suitable position, and the equipment can realize automatic filtration of solid particles in the sample oil. Therefore, in the early stage of sample preparation, it can greatly improve the preparation efficiency, reduce the degree of manual labor, and make the particles evenly distributed on the filter membrane, ensuring the consistency of the detection effect.

[0028] 2. In the present invention, the overall structural design of the filtering equipment is compact and reasonable. During the actual operation, the filter membrane and the sample bottle are placed in. After the equipment is started, the sample bottle can be automatically opened under the action of the lifting mechanism, and the filter membrane is automatically pressed. After the vacuum source is started, the sample oil is automatically filtered. After the filtration is completed, the particulate matter is retained on the filter membrane. Therefore, it is only necessary to take out the filter membrane for direct analysis. It is suitable for promotion and application in the detection and analysis of solid particles in insulating oil.

[0029] 3. In the present invention, a flushing liquid system is configured to automatically dilute the sample oil, and a stirring structure is configured to improve the mixing effect of the sample oil and the flushing liquid. After the experiment is completed, the liquid can be automatically drained to restore the equipment to its initial state. Compared with the cumbersomeness of the traditional sample pre-preparation, this structure can significantly reduce the complexity of the operation.

[0030] 4. In the present invention, the particle analysis method provided adopts microscopic imaging, which is suitable for the morphology observation and particle size analysis of conventional fault particles in oil (such as copper, iron, silicon, sludge, carbon deposits, fiber, organic matter, etc.), as well as the observation and testing of the surface structure of various opaque objects in oil (such as cellulose). It can quickly detect the composition and microscopic morphology of particulate contaminants in insulating oil, and help staff quickly determine the source of particulate contaminants. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is the overall structure of the filtration equipment Figure 1 ;

[0032] Figure 2 This is the overall structure of the filtration equipment Figure 2 ;

[0033] Figure 3 It is a schematic diagram of the filter device in the open state;

[0034] Figure 4 It is a schematic diagram of the internal structure of the filtering equipment;

[0035] Figure 5 It is a schematic diagram of the housing structure of the filtering equipment part;

[0036] Figure 6 This is a diagram of the funnel and handle structure. Figure 1 ;

[0037] Figure 7 This is a diagram of the funnel and handle structure. Figure 2 ;

[0038] Figure 8 is a schematic diagram of the structure of the filter membrane assembly;

[0039] Fig. 9 is a schematic diagram of the sample bottle structure;

[0040] Fig.10 It is a schematic diagram of the cross-sectional view of the sample bottle;

[0041] Fig.11 It is a schematic diagram of the bottom cover structure;

[0042] Fig.12 It is the process of filtering and microscopic analysis of solid particle samples in insulating oil;

[0043] Fig.13 It is a flow chart of microscopic image analysis of particles in insulation;

[0044] Fig.14 It is a schematic diagram of the distribution and analysis of the particle shape and appearance in oil;

[0045] Fig.15 It is a statistical diagram of particle size and distribution in oil.

[0046] Numbers shown in the accompanying drawings:

[0047] 1. Shell; 2. Cover; 3. Filter membrane assembly; 4. Sample bottle; 5. Liquid storage tank; 6. Vacuum bottle; 7. Funnel; 8. Drag handle; 9. Vacuum source;

[0048] 11. Upper partition; 12. Mounting through hole; 13. Guide hole; 14. Sliding groove;

[0049] 21. Lifting mechanism; 22. Stirring motor; 23. Pressure head; 24. Stirring shaft; 25. Nozzle; 26;

[0050] 31. filter membrane; 32. filter membrane holder;

[0051] 41. Bottle body; 42. Bottom cover; 43. Plug; 44. Driving block; 45. First connecting rod; 46. First guide rod; 47. First spring; 48. Liquid leakage channel; 49. Opening groove;

[0052] 61. Drain valve;

[0053] 71. Sample bottle positioning ring; 72. Flange; 73. Second spring; 74. Second guide rod; 75. Top column; 76. Second connecting rod;

[0054] 81. upper boss; 82. middle flange; 83. lower boss; 84. vacuum channel;

[0055] 91. Intake valve. DETAILED DESCRIPTION

[0056] The present invention will be further described with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope limited by the application.

[0057] Embodiment 1:

[0058] The present embodiment provides a solid particle detection and analysis system in transformer insulating oil, and in particular, a filtering device for preliminary sample preparation and an instrument for analyzing the sample in the detection and analysis system.

[0059] In this embodiment, the main structure of the filtering device is as follows: Figure 1-11 It mainly comprises a housing 1 and a cover 2 which can be flipped open. The cover 2 is arranged on one side of the housing 1 and is hingedly connected to the housing 1 to realize the opening and closing of the cover 2.

[0060] As shown in the figure, an upper partition 11 is arranged inside the shell 1, and the upper partition 11 divides the upper part of the shell 1 into an upper mounting cavity and a lower mounting cavity, and a mounting through hole 12 is arranged on the upper partition 11 (in order to facilitate the arrangement of parts, the mounting through hole 12 is located on one side of the shell 1), and a funnel 7 is arranged in the mounting through hole 12, and the funnel 7 is connected to the partition 11 by an elastic mechanical support component, so that the funnel 7 can move up and down and reset, the upper partition 11 is mainly used to support the funnel 7, and the mounting through hole 12 is used to provide a space for the funnel 7 to move up and down, and the funnel 7 is designed to be a structure that can be moved up and down, which is mainly to form a certain gap between the funnel 7 and the handle 8 below when the funnel 7 is in the upper position, so as to allow the filter membrane 32 to be placed therein, and after the funnel 7 moves downward, it can cooperate with the handle 8 to clamp and fix the filter membrane 32, so as to filter the particles in the sample oil through the filter membrane 32.

[0061] A sample bottle positioning ring 71 is arranged on the upper part of the funnel 7, and a top column 75 is arranged at the center of the sample bottle positioning ring 71. The sample bottle positioning ring 71 is mainly used to place the sample bottle 4. The sample bottle 4 is designed to be a structure that can be opened by the top column 75, and includes a bottle body 41 and a bottom cover 42 connected to the bottom of the bottle body 41, a leakage channel 48 is arranged on the bottom cover 42, and an elastic mechanical switch component is arranged at the leakage channel 48. In the above structural design, after the sample oil is injected into the sample bottle 4, since the bottom cover 42 is in a closed state, the sample oil will not flow out, and when the top column 75 applies force to the elastic mechanical switch component at the bottom cover 42, the bottom cover 42 is opened, and the sample oil can flow out from the bottom.

[0062] A handle 8 is provided below the funnel 7. The handle 8 mainly includes an upper boss 81, a middle flange 82 and a lower boss 83. A liquid channel is provided in the middle of the handle 8. The upper boss 81 is used to place the filter membrane 32. Specifically, the diameter of the upper boss 81 should be smaller than the diameter of the filter membrane 32 to facilitate the placement of the filter membrane 32. The upper boss 81 and the lower boss 83 are directly connected through the middle flange 82. The lower boss 83 is inserted into the vacuum bottle 6 below. A vacuum channel 84 is provided on one side of the integrated channel on the lower boss 83. The other end of the vacuum channel 84 is provided on one side of the middle flange 82 and is connected to the vacuum source 9 provided in the housing 1 through a pipeline. In order to facilitate vacuuming and releasing, corresponding three-way and air inlet valve 91 are provided on the pipeline in this embodiment.

[0063] In this embodiment, the external drive structure is designed on the cover body 2, which can ensure the compactness of the entire device. Specifically, a lifting mechanism is connected to the bottom of the cover body 2, and the lifting mechanism is mainly used to push the cover body 2 up and down (in order not to affect the flipping movement of the cover body 2, a movable plate driven by the lifting mechanism is set on the rear side of the shell 1, and the cover body 2 is hingedly connected to the movable plate). The lifting mechanism can be driven by an electric cylinder or other linear units. A pressure head 23 is provided on the cover body 2, and a stirring shaft 24 is installed on the pressure head 23. The stirring shaft 24 is connected to the stirring motor 22 (in order to make the structure more compact, the stirring motor 22 can be set outside the cover body 2 as shown in the figure). The design of the pressure head 23 is mainly used to drive the sample bottle 4 to move downward. As shown above, when the external force drives the sample bottle 4 to move downward, the sample bottle 4 can be automatically opened under the action of the top column 75, and the external force can also drive the funnel 7 to move.

[0064] As a preferred structure of the present embodiment, a groove 49 is provided at the bottom of the bottom cover 42 (mainly used to hide the elastic mechanical switch assembly), and the elastic mechanical switch assembly is designed according to the following structure: it includes a plug 43 for blocking the leakage channel 48 (in order to ensure the sealing performance, the leakage channel 48 and the plug 32 can be designed as a corresponding conical structure), and a driving block 44 is connected to the middle of the bottom of the plug 43, which is mainly used to cooperate with the top column 75. A first connecting rod 45 is respectively provided on both sides of the driving block 44, and a first guide rod 47 is fixedly provided in the groove 49. The first connecting rod 45 and the first guide rod 47 are slidably matched, and a first spring 47 is provided on the first guide rod 47 to apply force to the first connecting rod 45 downward. The first connecting rod 45 is used to connect the driving block 44 with the first guide rod 47, mainly to facilitate the liquid to flow out through the gap between the first connecting rods 45. In the above structure, in the absence of external force, after the sample bottle 4 is placed on the sample bottle positioning ring 71, the driving block 44 contacts the top column 75. When there is no external force, under the action of the first spring 47, the driving block 44 is at the bottommost position, and the bottom cover 42 is in a closed state. When the cover body 2 moves downward, force is applied to the sample bottle 4. Due to the limiting effect of the top column 75, it will push the driving block 44 to move upward to compress the first spring 47, and the plug 43 will move upward to open the leakage channel 48, and the liquid can flow out through the leakage channel 48. At the same time, under the force of the sample bottle 4, the funnel 7 will be pressed downward until its bottom contacts the handle 8.

[0065] Meanwhile, in this embodiment, as a preferred structure of the elastic mechanical support component, it is designed as follows: it includes a flange 72 and a second guide rod 74; the flange 72 is fixedly connected to the main body of the funnel 7, one end of the second guide rod 74 is fixedly connected to the flange 72, and the other end is slidably matched with the guide hole 13 provided on the upper partition 11, and a second spring 73 is provided on the second guide rod 74 to apply force to the flange 72 upward. In the above structure, in the absence of external force, the second spring 73 applies force to the funnel 7, so that it is always in the uppermost position, and at this time, there is a gap between its bottom and the handle 8 that can place the filter membrane 32, and when subjected to the downward pressure of the sample bottle 4, the second spring 73 is compressed, and the funnel 7 moves downward as a whole.

[0066] like Figure 7 As shown, in this embodiment, the top column 75 is supported by three second connecting rods 76 fixed to the inner wall of the funnel 7, and the liquid flows out through the gaps between the second connecting rods 76.

[0067] In order to ensure the sealing effect of the filtering device, sealing rings can be provided on the top surface of the upper boss 81 and the bottom surface of the funnel 7 .

[0068] When filtering the sample oil, in order to ensure the filtering effect, the sample oil should be diluted with a non-polluting flushing liquid first. After the experiment is completed and during the process, the container can also be cleaned and flushed with the flushing liquid to prevent particles from being retained on the container and affecting the test results. In order to achieve full-automatic filtration of the device, a liquid tank 5 and a pressure pump are also provided in the housing 1. The liquid tank 5 is used to store the flushing liquid, and the pressure pump is used to provide high pressure. At the same time, a plurality of nozzles 23 are provided on the pressure head 3, and the nozzle 23 is connected to the liquid tank 5 through a hose. The flushing liquid is injected into the nozzle 23 through the pressure pump, and is sprayed out by the nozzle 23 and then enters the sample bottle. At the same time, a drainage channel is provided at the bottom of the vacuum bottle 6, and a drainage valve 61 is provided on the drainage channel. The waste liquid after the experiment is completed is discharged through the drainage valve 61.

[0069] Furthermore, in this embodiment, in order to facilitate the use of the device and the removal and installation of the filter membrane 32, the filter membrane 32 is installed on a filter membrane holder 31, and the filter membrane 32 can be conveniently and accurately placed in a suitable position from the outside of the housing 1 through the filter membrane holder 31. Specifically, as shown in the figure, the filter membrane holder 32 includes a handheld plate and clamping arms on both sides, and a support groove for the filter membrane 32 to be placed is provided on the clamping arm (the distance between the clamping arms on both sides should be slightly larger than the diameter of the upper boss 81 and the bottom of the funnel 7); at the same time, a sliding groove 14 for the filter membrane holder 32 to slide is provided on one side of the housing 1. When installing the filter membrane 32, first place the filter membrane on the filter membrane holder 31 with tweezers, and then insert the filter membrane holder 31 into the sliding groove 14. At this time, the filter membrane 31 will be placed exactly in the middle of the upper boss 81.

[0070] In this embodiment, the main working process and principle of the filtering device are as follows.

[0071] 1) First, inject the sample oil into the sample bottle 4, open the cover 2 and put the sample bottle 4 into the sample bottle positioning ring 71, and then close the cover 2, at which time the bottom surface of the pressure head 23 just contacts the top of the sample bottle 4;

[0072] 2) Take out the filter membrane 32 from the filter membrane box, place it on the filter membrane holder 31 with tweezers, and insert the filter membrane holder 31 into the sliding groove 14;

[0073] 3) Turn on the pressure pump and stirring motor 22 of the liquid box 5, the flushing liquid is sprayed into the sample bottle 4 through the nozzle 25, and the stirring shaft 24 rotates to dilute the sample oil with the flushing liquid. After a certain period of time, stop the pressure pump and stirring motor 22;

[0074] 4) Start the lifting mechanism to move the cover 2 downward. At this time, the pressure head 23 presses the sample bottle 4 downward, the leakage channel 48 of the bottom cover 42 is opened, and the funnel 7 moves downward and presses on the filter membrane 31;

[0075] 5) Start the vacuum source 9 to evacuate the vacuum bottle 6. Under the vacuum effect, the liquid in the sample bottle 4 flows into the vacuum bottle 6 through the funnel 7, the filter membrane 32, and the handle 8 in sequence. The particles in the sample oil are retained on the filter membrane 32. After one cycle, the pressure pump of the liquid box 5 can be started again to flush the sample bottle with the flushing liquid to prevent particles from being left on the container;

[0076] 6) Start the lifting mechanism again to move the cover 2 upward, reset the sample bottle 4 and the funnel 7, and take out the filter membrane holder 32 to obtain the particles in the sample oil;

[0077] 7) The waste liquid can be discharged through the drain valve 61.

[0078] For the above steps, evenly distributed particulate matter is obtained on the filter membrane 31. The filter membrane 31 is moved to a watch dish, and the particles are analyzed and counted by a microscopic imager to obtain the size and type of the particles, thereby determining the actual composition of the particles.

[0079] Embodiment 2:

[0080] This embodiment provides a method for analyzing the particles obtained in the above embodiment 1.

[0081] In this embodiment:

[0082] The basic parameters of the microscope are as follows:

[0083] Measuring range: 1-3,000 microns;

[0084] Repeatability error: <3% (excluding the error caused by sample preparation);

[0085] Digital camera: 3 megapixels

[0086] Maximum optical magnification: 1600 times

[0087] Total system magnification: 5000 times, maximum optical magnification 1600 times

[0088] Maximum resolution: 0.1 micron / pixel;

[0089] The basic parameters of digital cameras are as follows:

[0090] Pixel size: 3.2μm x 3.2μm

[0091] Optical size: 1 / 2 inch;

[0092] Signal-to-noise ratio: 43dB;

[0093] Resolution: >1000 lines;

[0094] Programmable control of image size, brightness, gain, frame rate, and exposure time;

[0095] Frequency: <6 frames / second@2048X1536, 10 frames / second@1600X1200, 15 frames / second@1280X1024, 45 frames / second@640X480;

[0096] Sensor type: Line scan CMOS;

[0097] Lens interface: CS, C;

[0098] Dynamic range: 60dB;

[0099] Sensitivity: 1.0V@550nm / lux / s .

[0100] After taking a picture with a digital camera, the image is processed by a series of processes such as grayscale conversion, binarization, segmentation, deletion, cutting, pasting, scaling, and filling. By processing the image, the measurement software automatically counts the number of particles, and then calculates the number of pixels contained in each particle to obtain the particle area, equivalent diameter, equivalent perimeter, actual perimeter, circularity and other parameters. Through particle size classification, the particle size distribution table and distribution diagram required by the user and typical parameters such as d10, d50, d90 are obtained, and the number distribution or volume distribution can be selected as needed; including original data (sample information and test information); analysis data (particle size distribution table / particle size distribution diagram); graphics (frequency distribution histogram and cumulative distribution curve); typical results (median diameter, average diameter, circularity, etc.). According to the above-mentioned microscopic image of particles in oil, its edge is detected, and OpenCV is used to identify various types of particles in the picture. Finally, the above-mentioned extracted images are used as training samples to train the learning vector quantization neural network, and the output of edge pixels and non-edge pixels is completed by using its own powerful learning function and adaptability. All typical images of various types of pollution particles are stored in image files, and computer technology can be used to analyze the typical types and contents of pollution particles in the image files.

[0101] like Fig.14 , 15 , which is a reference diagram related to the morphology, appearance and size distribution statistics of particles in oil provided in this embodiment.

[0102] It can be seen that the detection and analysis system provided by the above embodiment can prepare sample particles quickly and efficiently, which reduces the manual participation in sample pre-processing and simplifies the process. At the same time, image processing technology can be used to analyze the particles in the sample oil, and the composition and microscopic morphology of the particles in the insulating oil can be quickly detected, helping staff to quickly determine the source of particulate contaminants.

Claims

1. A solid particle detection and analysis system in transformer insulating oil, comprising a filtering device, wherein the filtering device comprises a housing and a cover that can be flipped open, characterized in that: An upper partition is provided in the shell, a mounting through hole is provided on the upper partition, a funnel is provided in the mounting through hole, and the funnel is connected to the partition by an elastic mechanical support component so that the funnel can move up and down and reset; A sample bottle positioning ring is arranged on the upper part of the funnel, a top column is arranged at the center of the sample bottle positioning ring, a sample bottle is installed in the sample bottle positioning ring, the sample bottle comprises a bottle body and a bottom cover connected to the bottom of the bottle body, a liquid leakage channel is arranged on the bottom cover, an elastic mechanical switch assembly is arranged at the liquid leakage channel, and the elastic mechanical switch assembly enables the liquid leakage channel to be opened under the action of the top column when the sample bottle moves downward; A handle is provided below the funnel, and the handle includes an upper boss, a middle flange and a lower boss. The upper boss is used to place the filter membrane, and the lower boss is used to connect the vacuum bottle. A vacuum channel is provided on the handle, and the vacuum channel is connected to a vacuum source provided in the housing. The cover is connected to a lifting mechanism, a pressure head is provided on the cover, a stirring shaft is installed on the pressure head, the stirring shaft is connected to the stirring motor, the position of the pressure head corresponds to the vacuum bottle when the cover is closed, when the lifting mechanism drives the cover to move downward, the pressure head applies force to the sample bottle, so that the sample bottle opens and connects with the funnel, and at the same time, the funnel moves downward and cooperates with the upper boss to clamp and fix the filter membrane, and when the lifting mechanism is reset, the sample bottle and the funnel are reset accordingly; The bottom of the bottom cover is provided with a slot, the elastic mechanical switch assembly includes a plug for blocking the leakage channel, a driving block is connected in the middle of the bottom of the plug, first connecting rods are provided on both sides of the driving block, a first guide rod is fixedly provided in the slot, the first connecting rod is slidably matched with the first guide rod, and a first spring is provided on the first guide rod to apply force to the first connecting rod downward, and the driving block and the first connecting rod are both located in the slot; The elastic mechanical support assembly includes a flange and a second guide rod; the flange is fixedly connected to the funnel body, one end of the second guide rod is fixedly connected to the flange, and the other end is slidably matched with a guide hole provided on the upper partition, and a second spring is provided on the second guide rod to apply force to the flange upward; The filtering device also includes a filter membrane holder, which includes a handheld plate and clamping arms on both sides, and a supporting groove for placing the filter membrane is provided on the clamping arms; A sliding groove for sliding the filter membrane frame is arranged on one side of the shell, and after the filter membrane is installed on the filter membrane frame, it can be pushed to the upper boss by the sliding groove.

2. The solid particle detection and analysis system in transformer insulating oil according to claim 1 is characterized in that: The top column is supported by a plurality of second connecting rods fixed to the inner wall of the funnel.

3. The solid particle detection and analysis system in transformer insulating oil according to claim 1 is characterized in that: The top surface of the upper boss and the bottom surface of the funnel are both provided with sealing rings.

4. The solid particle detection and analysis system in transformer insulating oil according to claim 1 is characterized in that: A liquid tank and a pressure pump are also provided in the housing, and the liquid tank is used to store flushing liquid; A plurality of nozzles are also arranged on the pressure head, and the nozzles are connected to the liquid tank through a hose; A liquid discharge channel is arranged at the bottom of the vacuum bottle, and a liquid discharge valve is arranged on the liquid discharge channel.

5. The solid particle detection and analysis system in transformer insulating oil according to claim 1 is characterized in that: One end opening of the vacuum channel is arranged on the bottom surface of the lower boss, and the other end opening is arranged on the middle flange. A pipeline is installed at the middle flange to connect to the vacuum source, and a three-way and an air inlet valve are arranged on the pipeline.

6. The solid particle detection and analysis system in transformer insulating oil according to claim 1 is characterized in that: Also included is a microscopic imager, which is used to analyze the particles filtered on the filter membrane.

7. A method for detecting and analyzing solid particles in transformer insulating oil, characterized in that: The steps include: S1. Filter the quantitative insulating oil through the filtering device of the detection and analysis system according to any one of claims 1 to 6, separate the solid particles in the insulating oil to the filter membrane, and move the filter membrane to a watch glass; S2. Use a microanalyzer to count the number of particles, particle size, and the number of pixels contained in the quantitative oil products, calculate the equivalent area circle and equivalent spherical volume of each particle, and thus obtain the equivalent area diameter and equivalent spherical volume diameter of the particle and the circularity parameter. Then, perform graded statistics on all particles to obtain the particle size distribution and circularity distribution information, and determine the actual composition of the particulate pollutants based on the analysis information.

Images