Device and method for rapidly detecting wettability of insulation paper

Abstract

The invention relates to the technical field of insulation detection, in particular to an insulation paper wettability detection device and method. The invention discloses a rapid detection device and method for wettability of insulation paper. The rapid detection device comprises a data processor, a timing detector, a camera, a laser transmitter, a laser receiver, display equipment arranged outside and a liquid storage device arranged on a cross beam, wherein the data processor, the timing detector, the camera, the laser transmitter and the laser receiver carry out data transmission with one another; the bottom of the liquid storage device is provided with a dropping pipette and a dropping nozzle which are communicated with each other, liquid drops drop onto an insulation paper sample from the dropping nozzle, the outer side of the enclosure is provided with a timing detector, the timing detector is provided with a laser receiving and transmitting device, and the lower side of the platform is connected with a collector for collecting liquid through a flow guide pipe. By directly measuring the infiltration time of the liquid drops on the insulation paper, the interference of the pipe diameter of the capillary pipe is avoided, the wettability of the insulation paper can be rapidly and accurately measured, reliable data support is provided for production and maintenance of oil paper insulation equipment, and wide application in the field of electrical equipment manufacturing and detection can be promoted.

Description

Technical Field

[0001] The present invention relates to the technical field of insulating paper detection, and in particular to a device and method for detecting wettability of insulating paper. Background Art

[0002] In the oil-paper insulation system, good wettability between insulating paper and insulating oil is crucial to ensure the safe and stable operation of power equipment.

[0003] The traditional method for detecting the wettability of insulating paper disclosed in the "Effect of the Pore Structure of Electrospun Polyimide Insulation Paper on Its Impregnation and Breakdown Characteristics" in the "Proceedings of the CSEE" is to insert the cardboard into the insulating oil and measure the height of the oil rising in the cardboard. However, this method has inherent defects, because according to the principle of capillary phenomenon, when the force is balanced, the gravitational force of the solid on the liquid is equal to the weight of the rising volume. The thinner the capillary diameter, the higher the capillary height; if the capillary diameter is thicker, the more liquid per unit height, the lower the liquid rises. However, when the actual oil-paper insulation is working, the insulating paper is completely immersed in the insulating oil, not in a partial infiltration state in the capillary, so the degree of infiltration should only be related to the intrinsic wettability between the solid and the liquid, and has nothing to do with external factors such as the capillary diameter. This traditional measurement method is greatly affected by the capillary diameter, resulting in the inability to accurately reflect the true infiltration characteristics of the insulating paper, and it is difficult to meet the current power equipment The demand for accurate detection of insulating materials, there is an urgent need for a new device that can eliminate interference factors and directly measure the wettability of insulating paper.

[0004] Chinese patent CN 109870379 A discloses a detection device and a wettability detection method for detecting wettability, which is used to solve the problem that the wettability test method of battery pole pieces and diaphragms in the prior art is not precise enough and subjective, resulting in inaccurate testing. However, the detection method and structure of the patent are unreasonable, the operation is complicated, and the data is inaccurate. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a rapid detection device and method for the wettability of insulating paper, which drips liquid droplets to the insulating paper sample below at a stable flow rate, and the outlet end can finely adjust the distance from the insulating paper sample with the help of a lifting device, thereby ensuring the consistency of the falling state of the liquid droplets. A rapid detection device and method for the wettability of insulating paper are constructed.

[0006] In order to achieve the above-mentioned invention objectives, the present application provides a device for quickly detecting the wettability of insulating paper, including a data processor for data transmission with each other, a timing detector, a camera, a signal receiving and transmitting device, an external display device and a bracket for fixing and supporting, a liquid reservoir is provided on the crossbeam of the bracket, a dropper and a dropper nozzle connected to each other are provided at the bottom of the liquid reservoir, the outlet end of the dropper nozzle is located directly above the insulating paper sample to be detected, so that droplets drip from the dropper nozzle onto the insulating paper sample, an enclosure made of transparent material is provided on the outside of the insulating paper sample, and two or more corresponding laser transmitters, laser receivers and timing detectors are provided on the outside of the enclosure, the enclosure and the timing detector are both arranged on the same plane of the platform, the timing detector is arranged on the laser transmitter or the laser receiver, and the lower side of the platform is connected to a collector for collecting liquid through a guide tube.

[0007] Preferably, a camera that can be raised and lowered is provided on a bracket above the insulating paper sample.

[0008] Preferably, a liquid level observation window communicating with the interior is provided on one side of the liquid reservoir.

[0009] Preferably, the dripping tube is provided with a regulating valve for controlling the dripping speed.

[0010] Preferably, a valve is provided on the flow guide pipe.

[0011] Preferably, a lifting device for adjusting the height is provided on the lower side of the platform.

[0012] Preferably, the lifting device is arranged on a base plate.

[0013] Preferably, the enclosure is made of transparent material.

[0014] The present invention also provides a detection method using a device for quickly detecting the wettability of insulating paper, comprising the following steps:

[0015] Step 1: Preparation

[0016] Place the bracket firmly on the horizontal platform, fix the dropper vertically on the beam, calibrate the initial drop rate of the drop rate regulating valve, seamlessly fit the insulating paper sample in the middle of the enclosure, start self-test of the timing detector, data processor, laser transmitter, and laser receiver, return all parameters to zero, fine-tune the height of the dropper outlet from the sample platform, and complete the initialization preparation;

[0017] Step 2: Detection and data acquisition phase

[0018] The regulating valve is turned to make the droplet fall. When the droplet falls vertically and touches the insulating paper sample, the laser light path emitted by the laser transmitter is blocked by the droplet. The part of the droplet that is higher than the surface of the insulating paper sample causes the laser to be refracted and reflected, changing the original normally received laser signal. This changed signal triggers the operation of the timing module in the timing detector and subsequent actions. The changed laser signal is input into the data processor, and the timing detector is triggered to start working to monitor the infiltration process of the insulating paper sample; at the same time, the camera is triggered to shoot. When the droplet completely disappears in the insulating paper sample, there is no droplet blocking the laser light path. The signal returns to normal, the timing of the timing detector is terminated, and the timing data of the infiltration of the insulating paper sample is transmitted to the data processor for storage, and the camera is triggered again to shoot.

[0019] Step 3: Data processing phase

[0020] For the image data acquired by the camera, the data processor performs subtraction and filtering on the RGB matrix obtained from the two shots after each test of the sample, removes the pixels with high similarity, and then calculates the number of all non-zero elements after a 2×2 maxpooling operation. The larger the value, the better the wettability, and vice versa.

[0021] Step 4: For the infiltration time data, after collecting multiple sets of infiltration time data, the data processing unit calculates the mean and standard deviation, and after data export, draws a bar chart to visually compare the infiltration differences of each sample, analyzes the quality stability of the insulation paper batch, and the influence of potential factors such as environmental temperature and humidity on the infiltration performance, clarifies the optimization direction of the insulation paper infiltration, and provides data support for subsequent production improvement or equipment operation and maintenance;

[0022] Step 5: Repeat steps 2 and 2 above 5-10 times, changing different batches of samples or adjusting the dripping parameters.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present invention has the advantages of accurate measurement, high efficiency and fast speed, rich data, convenient operation and wide range of mixed applications;

[0025] 2. The device provided by the present invention has a compact and reasonable structure design, humanized operation, and simple and easy sample replacement with low labor cost and time;

[0026] 3. The present invention is helpful for the design and optimization of oil-paper insulation, reduces R&D and production costs, can shorten the R&D cycle, and has certain market competitiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention.

[0028] Figure 1 This is a structural diagram of the device for quickly detecting the wettability of insulating paper according to the present invention;

[0029] Figure 2 The present invention provides a flowchart of the method for quickly detecting the wettability of insulating paper.

[0030] In the figure, 1-liquid reservoir, 2-rod, 3-drip tube, 4-regulating valve, 5-drip nozzle, 6-droplet, 7-insulating paper sample, 8-timing detector, 9-platform, 10-collector, 11-valve, 12-flow guide tube, 13-fine-tuning device, 14-base plate, 15-data processor, 161-laser transmitter, 162-laser receiver, 163-laser optical path, 17-transparent enclosure, 18-camera, 19-bracket, 20-liquid level observation window. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0032] Example 1

[0033] like Figure 1 and 2As shown, the present invention provides a device for quickly detecting the wettability of insulating paper, comprising a data processor 15 for mutually transmitting data, a timing detector 8, a camera 18, a signal receiving and transmitting device, an external display device and a bracket 19 for fixing and supporting, a liquid reservoir 1 is provided on a crossbeam 2 of the bracket 19, a dropper 3 and a dropper 5 connected to each other are provided at the bottom of the liquid reservoir 1, an outlet end of the dropper 5 is located directly above an insulating paper sample 7 to be detected, so that a droplet 6 is dripped from the dropper 5 onto the insulating paper sample 7, and a fence 17 is provided on the outside of the insulating paper sample 7. In this embodiment, the fence 17 is transparent. The outer side of the enclosure 17 is made of a bright material, and two or more corresponding laser emitters 161 and laser receivers 162 are arranged on the outer side of the enclosure 17. The laser receiver 162 can be used to receive the laser emitted by the laser emitter 161 and propagated along the laser optical path 163. When the droplet 6 falls on the straight line of the laser optical path 163 on the surface of the insulating paper sample 7, a bulge will be generated on the surface of the insulating paper sample 7, and the laser optical path 163 will be blocked. The laser receiver 162 on the other side cannot receive the laser signal propagated along the laser optical path 163. The timing detector 8, the enclosure 17 and the timing detector 8 are all arranged on the same plane of the platform 9. In this embodiment, in order to synchronously ensure that the data is transmitted in time, the timing detector 8 is arranged on the laser emitter 161 or the laser receiver 162, and the lower side of the platform 9 is connected to the collector 10 for collecting liquid through the guide tube 12. In order to record and process relevant data, a camera 18 that can be lifted up and down is arranged on the bracket 19 above the insulating paper sample 7. Among them, in order to facilitate the replacement of insulating paper samples of different sizes, the platform 9 on the bracket 19 adopts a detachable structure.

[0034] In order to control and timely adjust the liquid drop 6 dripping from the drip nozzle 5 onto the insulating paper sample 7, a liquid level observation window 20 communicating with the interior is provided on one side of the liquid reservoir 1.

[0035] In order to control and adjust the dripping speed of the droplets 6, a regulating valve 4 for controlling the dripping speed is provided on the dripping tube 3. Preferably, a valve 11 is provided on the guide tube 12. For the convenience of the operator, a lifting device 13 is provided on the lower side of the platform 9 on the bottom plate 14 for adjusting the height.

[0036] Among them, the timing detection module in the timing detector 8 is electrically connected to the dripping mechanism, and starts timing from the moment the droplet falls. The timing starts at the moment the droplet 6 contacts the insulating paper sample 7, and the timing is stopped when the droplet on the insulating paper sample 7 is completely soaked and disappears on the sample surface, and the droplet soaking time is recorded. In this embodiment, the timing detection module in the timing detector 8 adopts a high-precision electronic timer, and the timing accuracy reaches the millisecond level.

[0037] The visual module in the camera 18 is electrically connected to the timing detection module in the timing detector 8 for signal transmission, and is used to capture the droplet wetting process and output an RGB matrix of the droplet wetting image;

[0038] The data processing module in the data processor 15 is in communication with the timing detection module and the visual module, and is used to receive and store data, and can transmit the data to an external display device for display.

[0039] The data processing unit has a data analysis function and can perform statistical analysis on the data of multiple measurements, such as calculating the average value and standard deviation of the infiltration time, and drawing the infiltration time change curve, and statistically analyzing the RGB matrix information of the droplet infiltration image. The statistical analysis of the RGB matrix information of the droplet 7 infiltration image is completed by performing matrix subtraction, filtering, and 2×2 maxpooling operations on the matrix before and after the test, and then summing the number of elements that are not 0.

[0040] The present invention also provides a detection method using a device for quickly detecting the wettability of insulating paper, comprising the following steps:

[0041] Step 1: Preparation

[0042] The bracket 19 made of stainless steel material is firmly placed on the horizontal platform 9, and the liquid reservoir 1 and the dropper 3 in the dripping mechanism made of glass material are installed in sequence, and it is ensured that the liquid reservoir 1 is well sealed, the dropper 3 is vertical and not skewed, and the initial dripping speed of the regulating valve 4 is carefully calibrated; the insulating paper sample 7 fixing platform 9 is accurately embedded in the predetermined position of the frame, and the transparent material annular enclosure 17 is seamlessly fitted, and the pipes of the liquid collection device are tightly connected without leakage to ensure that each valve opens and closes smoothly; the timing detector 8 circuit is correctly connected, the data processor 15, the laser transmitter 161, and the laser receiver 162 are powered on for self-test, all parameters are reset to zero, and the height of the dropper 6 outlet from the sample platform is fine-tuned to complete the initialization preparation; among them, the timing detector 8 and the data processor 15 use the laser communication receiving module and storage module based on STM32, and the visual module uses the OpenMV visual module;

[0043] Select an insulating paper sample 7 of standard size 10.0 cm × 10.0 cm, wipe the surface with a clean, dry soft cloth to remove impurities and dust, and place it stably in the center of the sample fixing platform 9, ensuring that the insulating paper sample 7 is flat without wrinkles or warping, and that an appropriate safety distance is reserved between the edge and the enclosure.

[0044] Step 2: Detection and data acquisition phase

[0045] Turn on the dripping device, turn the regulating valve 4 to let the droplet 6 fall. When the droplet 6 falls vertically and touches the insulating paper sample 7, the laser emitted by the laser transmitter 16 propagates along the laser optical path 163 and is blocked by the droplet 6. The portion of the droplet 6 that is higher than the surface of the insulating paper sample 7 causes the laser to be refracted and reflected, thereby changing the original normally received laser signal. This changed signal triggers the operation of the timing module in the timing detector 8 and subsequent actions. The changed laser signal is input into the data processor 15, and the laser transmitter 16 emits a laser optical path 163. The laser optical path 163 is blocked by the droplet 7, and the signal of the laser optical path 163 is changed. The signal of the laser light path 163 is input into STM32, and the signal of the change of the laser light path 163 is transmitted to the data processor 15, and the timing detector 8 is triggered to start working to monitor the infiltration process of the insulating paper sample 7; at the same time, the camera 18 is triggered to shoot, and when the droplet 7 completely disappears in the insulating paper sample 7, the signal of the laser light path 163 returns to normal, the timing of the timing detector 8 is terminated, and the timing data of the infiltration of the insulating paper sample 7 is transmitted to the data processor 15 for storage, and the camera 18 is triggered again to shoot to obtain the sample data shot, and the operation is repeated 5-10 times, and different batches of samples are replaced or the dripping parameters are adjusted: dripping speed, droplet volume, and the test conditions are expanded;

[0046] Step 3: Data processing phase

[0047] For the image data acquired by the camera 18, the data processor 15 performs subtraction and filtering on the RGB matrix obtained from the two shots after each test of the sample, removes the pixels with high similarity, and then calculates the number of all non-zero elements after a 2×2 maxpooling operation. The larger the value, the better the wettability, and vice versa.

[0048] Step 4: For the infiltration time data, after collecting multiple sets of infiltration time data, the processing module in the data processor 15 calculates the mean and standard deviation, and after the data is exported, draws a bar chart to visually compare the infiltration differences of each sample, analyzes the quality stability of the insulating paper batch, and the influence of the infiltration performance on the potential factors such as environmental temperature and humidity, and clarifies the optimization direction of the infiltration of the insulating paper, so as to provide data support for subsequent production improvement or equipment operation and maintenance;

[0049] Step 5: Repeat steps 2-4 above 5-10 times, changing different batches of samples or adjusting the dripping parameters until the test is completed.

[0050] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0051] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A device for quickly detecting the wettability of insulating paper, comprising a data processor (15) for mutually transmitting data, a timing detector (8), a camera (18), a signal receiving and transmitting device, an external display device and a bracket (19) for fixing and supporting, wherein a liquid reservoir (1) is provided on a crossbeam (2) of the bracket (19), characterized in that: The bottom of the liquid reservoir (1) is provided with a dripping tube (3) and a dripping nozzle (5) which are connected to each other. The outlet end of the dripping nozzle (5) is located directly above the insulating paper sample (7) to be tested. A baffle (17) is provided on the outside of the insulating paper sample (7) to allow the liquid droplets (6) to drip from the dripping nozzle (5) onto the insulating paper sample (7). The outside of the baffle (17) is provided with two or more corresponding laser emitters (161), laser receivers (162) and timing detectors (8). The baffle (17) and the timing detector (8) are both arranged on the same plane of the platform (9). The timing detector (8) is arranged on the laser emitter (161) or the laser receiver (162). The lower side of the platform (9) is connected to a collector (10) for collecting liquid through a guide tube (12).

2. The device for quickly detecting the wettability of insulating paper according to claim 1, characterized in that: A camera (18) that can be lifted up and down is provided on a bracket (19) above the insulating paper sample (7).

3. The device for quickly detecting the wettability of insulating paper according to claim 1, characterized in that: A liquid level observation window (20) communicating with the interior is provided on one side of the liquid storage container (1).

4. The device for quickly detecting the wettability of insulating paper according to claim 1, characterized in that: The dripping tube (3) is provided with a regulating valve (4) for controlling the dripping speed.

5. The device for quickly detecting the wettability of insulating paper according to claim 1, characterized in that: The flow guide pipe (12) is provided with a valve (11).

6. The device for quickly detecting the wettability of insulating paper according to claim 1, characterized in that: A lifting device (13) for adjusting the height is provided on the lower side of the platform (9).

7. The device for quickly detecting the wettability of insulating paper according to claim 1, characterized in that: The lifting device (13) is arranged on a bottom plate (14).

8. The device for quickly detecting the wettability of insulating paper according to claim 1, characterized in that: The enclosure (17) is made of transparent material.

9. A method for detecting the wettability of insulating paper using the device for rapid detection of the wettability of insulating paper as claimed in any one of claims 1 to 8, comprising the following steps: Step 1: Preparation The bracket (19) is stably placed on the horizontal platform (9), the dropper (1) is vertically fixed on the crossbeam (2), the initial drop rate of the dropper speed regulating valve (4) is calibrated, the insulating paper sample (7) is seamlessly attached to the middle of the enclosure (7), the timing detector (8), the data processor (15), the laser transmitter (161) and the laser receiver (162) are powered on and self-checked to determine whether they are working normally, all parameters are reset to zero, and the height of the dropper (3) outlet from the sample platform (9) is finely adjusted to complete the initialization preparation; Step 2: Detection and data acquisition phase The regulating valve (4) is rotated to make the liquid drop (6) fall into a dripping state. When the liquid drop (6) falls vertically and touches the insulating paper sample (7), the laser light path (163) emitted by the laser transmitter (161) is blocked by the liquid drop (6). The portion of the liquid drop (6) that is higher than the surface of the insulating paper sample (7) changes the original normally emitted and received laser signal due to refraction and reflection. The changed signal triggers the operation of the timing module in the timing detector (8) and subsequent actions. The changed laser signal is input into the data processor (15), and the timing detector (8) is triggered to start working to monitor the wetting process of the insulating paper sample (7); at the same time, the camera (18) is triggered to take pictures. When the liquid drop (7) completely disappears in the insulating paper sample (7), the laser light path (163) signal returns to normal, the timing of the timing detector (8) is terminated, and the timing data of the wetting of the insulating paper sample (7) is transmitted to the data processor (15) for storage, and the camera (18) is triggered again to take pictures. Step 3: Data processing phase For the image data acquired by the camera (18), the data processor (15) performs a subtraction operation and filtering on the RGB matrix obtained by the two shots, and removes the pixels with high similarity. After a 2*2 maxpooling operation, the number of all non-zero elements is calculated. The larger the value, the better the wettability, and vice versa. During the operation, the same parts in the two photos are subtracted, and the number of pixels in the remaining different parts is counted, thereby realizing the detection and characterization of the wettability. Step 4: For the infiltration time data, after collecting multiple sets of infiltration time data, the data processing unit calculates the mean and standard deviation, and after data export, draws a bar chart to visually compare the infiltration differences of each sample, analyzes the quality stability of the insulation paper batch, and the influence of potential factors such as environmental temperature and humidity on the infiltration performance, clarifies the optimization direction of the insulation paper infiltration, and provides data support for subsequent production improvement or equipment operation and maintenance; Step 5: Repeat steps 3-4 above 5-10 times, changing different batches of samples or adjusting the dripping parameters for testing.

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