Sensor, detection method and device for impurities in oil

Abstract

The invention provides an oil impurity sensor and a detection method and device. Comprising a sensing electrode and a reference electrode, and the sensing electrode and the reference electrode are configured to at least supply oil to flow through the surfaces of the sensing electrode and the reference electrode; wherein the sensing electrode is used for being in oil-solid contact with oil for electrification so as to generate a sensing voltage signal, and the reference electrode is used for being in contact with the oil so as to generate a reference voltage signal; the sensing electrode is made of an oleophobic material, and the reference electrode is made of a lipophilic material.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of industrial mineral oil quality monitoring, and particularly relates to an oil impurity sensor, a detection method and a device. BACKGROUND

[0002] Mineral insulating oil plays an important role in insulation and cooling in oil-immersed power transmission and distribution equipment, and mineral fuel is the main fuel of aerospace vehicles. However, mineral oil inevitably contacts various external factors during production, transportation and use, thereby introducing various impurities, which have a significant impact on the normal operation of the equipment and the performance of the fuel. Therefore, detecting the type and content of impurities in the mineral oil is crucial for ensuring the stable operation of the power equipment and prolonging the service life of the fuel engine.

[0003] The traditional mineral oil impurity detection method relies on laboratory chromatographic analysis, which has the following defects: 1) sampling error: the oil sample is easily contaminated by external gas during collection and transportation, resulting in distorted data of water content, acid value, etc.; 2) poor timeliness: periodic detection cannot timely find early faults of the equipment; 3) complex equipment structure: the DGA (dissolved gas analysis) system needs a constant temperature room environment, and has low field applicability. In view of the above problems, the application provides an in-situ detection technology for mineral oil impurities based on oil-solid contact electrification, which realizes in-situ rapid monitoring and analysis of the liquid composition of the mineral oil by optimizing the sensor structure and the friction-sensitive layer. SUMMARY

[0004] Therefore, the application provides an oil impurity sensor, a detection method and a device, which aims to detect the impurities in the oil.

[0005] In a first aspect, the application provides an oil impurity sensor, comprising: a sensing electrode and a reference electrode, the sensing electrode and the reference electrode being configured to at least allow oil to flow over their surfaces; The sensing electrode is configured to generate a sensing voltage signal by oil-solid contact electrification with the oil, and the reference electrode is configured to generate a reference voltage signal by contacting the oil. The sensing electrode is formed of an oleophobic material, and the reference electrode is formed of an oleophilic material.

[0006] Optionally, the sensing electrode comprises a laminated electrode layer, a substrate layer and an oleophobic coating layer.

[0007] Optionally, the reference electrode comprises a laminated electrode layer and a substrate layer.

[0008] Optionally, the mineral static contact angle of the oleophobic coating layer is greater than 120℃.

[0009] Optionally, the oleophobic coating is obtained by spraying an oleophobic coating material, and the oleophobic coating material comprises a PTFE nanoparticle aqueous solution.

[0010] Optionally, the base layer comprises a polydimethylsiloxane layer.

[0011] Optionally, the thickness of the oleophobic coating is 200 μm to 400 μm.

[0012] Optionally, the oil impurity sensor further comprises: a first cover plate, an oil passage cavity, a second cover plate, and a navigation plug; The first cover plate, the oil passage cavity, and the second cover plate enclose a closed cavity; the oil passage cavity is provided with an oil inlet and an oil outlet on the side surface; The sensing electrode is arranged on the inner surface of the first cover plate, and the reference electrode is arranged on the inner surface of the second cover plate; The navigation plug is used to guide the signals collected by the sensing electrode and the reference electrode.

[0013] In a second aspect, the application provides a method for detecting impurities in oil, which is applied to the oil impurity sensor as described in any one of the above aspects, and comprises: acquiring a sensing voltage signal output by the sensing electrode; acquiring a reference voltage signal output by the reference electrode; determining the impurity components in the mineral oil according to the sensing voltage signal and the reference voltage signal.

[0014] In a third aspect, the application provides an oil impurity detection device, which comprises the oil impurity sensor as described in any one of the above aspects.

[0015] The technical scheme provided by the application has the beneficial effects including: The application provides an oil impurity sensor, which comprises a sensing electrode and a reference electrode.

[0016] In addition, the reference electrode is used to generate the reference voltage signal by contacting the oil, and the accuracy is higher and the adaptability to the environment is stronger than that of the reference voltage signal generated by the ground electrode (the ground electrode is disturbed by environmental factors such as a magnetic field, so that the reference voltage signal generated by the ground electrode fluctuates. The reference electrode is provided in the application, and the voltage signal generated by the reference electrode is generated by contacting the oil. In addition, the reference electrode is oleophilic material, so that the reference voltage signal generated by the reference electrode is weak and will not change due to environmental factors, and can be used as a reference for the sensing voltage signal. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the application or the prior art, the drawings needed in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0018] Figure 1 A structural schematic diagram of an oil impurity sensor provided by an embodiment of the application.

[0019] Figure 2 A structural schematic diagram of a sensing electrode provided by an embodiment of the application.

[0020] Figure 3 A structural schematic diagram of a reference electrode provided by an embodiment of the application.

[0021] Figure 4The flow chart of the method for detecting impurities in oil provided by an embodiment of the application.

[0022] Figure 5 The structural block diagram of the device for detecting impurities in oil provided by an embodiment of the application.

[0023] Figure 6 The structural schematic diagram of the sensor data acquisition module provided by an embodiment of the application.

[0024] Figure 7 The structural schematic diagram of the oil circuit and the control module thereof provided by an embodiment of the application.

[0025] Figure 8 The schematic diagram of the device for detecting impurities in oil provided by an embodiment of the application in use.

[0026] The reference signs are as follows: 10: impurity sensor in oil; 100: device for detecting impurities in oil; 11: sensing electrode; 111: insulation layer; 112: electrode layer; 113: substrate layer; 114: oil-repellent coating; 12: reference electrode; 13: first cover plate; 14: oil circuit cavity; 141: oil inlet; 142: oil outlet; 15: second cover plate; 16: plug; 20: sensor data acquisition module; 201: interface board; 202: M6Y2C core board; 203: 4G APN board; 204: power supply board; 205: indicator light module.

[0027] 31: oil circulation loop; 32: oil sample measurement loop; 33: oil return unit loop; 34: emptying pipeline; 35: breathing pipeline; 301: manual valve; 302: automatic valve; 303: filter; 304: oil pump; 305: pressure sensor; 306: oil tank; 307: one-way valve; 41: transformer; 42: power supply; 401: flange; 402: oil inlet pipeline; 403: oil outlet pipeline; 404: cable. DETAILED DESCRIPTION

[0028] In order to make the objectives, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below with reference to the drawings in the present application. Obviously, the described embodiments are some embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0029] Figure 1 The structural schematic diagram of the impurity sensor in oil provided by the present application. Referring to Figure 1 , comprising: Sensing electrode 11 and reference electrode 12; The sensing electrode 11 is configured to generate electrical signals through immersion and oil-solid friction, and the reference electrode 12 is configured to sense the electrical signals generated during immersion.

[0030] See Figure 2 As an example, the sensing electrode includes: a stacked insulating layer 111, an electrode layer 112, a substrate layer 113, and an oleophobic coating 114.

[0031] See Figure 3 As an example, the reference electrode includes: a stacked insulating layer 111, an electrode layer 112, and a base layer 113.

[0032] As an example, insulation layer 111 is a layer of electrical insulating tape, which mainly serves to insulate against external interference signals.

[0033] As an example, electrode layer 112 is a gold-plated electrode used to connect to a wire to bring out the output signal.

[0034] As an example, the substrate layer 113 includes a polydimethylsiloxane layer.

[0035] As an example, the mineral static contact angle of the oleophobic coating 114 is greater than 120°.

[0036] As an example, the oleophobic coating 114 is obtained by spraying an oleophobic coating comprising an aqueous solution of PTFE nanoparticles.

[0037] As an example, the thickness of the oleophobic coating 114 is 200 μm to 400 μm.

[0038] As an example, oil impurity sensors also include: First cover plate 13, oil passage cavity 14, second cover plate 15, aviation plug 16.

[0039] The first cover plate 13, the oil passage cavity 14, and the second cover plate 15 form a closed cavity. An oil inlet 141 and an oil outlet 142 are provided on the side of the oil passage cavity 14. The sensing electrode 11 is disposed on the inner surface of the first cover plate 13, and the reference electrode 12 is disposed on the inner surface of the second cover plate 15. The aviation plug 16 is used to export the signals collected by the reference electrode and the sensing electrode.

[0040] The signals generated by the sensing electrode 11 and the reference electrode 12 are led out to the pendant 16 via wires.

[0041] It should be noted that oil valves are installed at the oil inlet 141 and the oil outlet 142. The functions of the oil inlet 141 and the oil outlet 142 are to introduce oil and to discharge oil.

[0042] In the embodiment, the working process of the impurity in oil sensor is as follows: the mineral oil flows into the hollow structure inside the oil passage cavity through the oil inlet, and the oil-solid friction electrification occurs between the oil and the sensing electrode under the action of oil pressure to generate a periodic friction electric output voltage signal. At the same time, the reference electrode will generate a stable reference output voltage signal due to immersion in the oil. After the two voltage signals are introduced through the plug, they are output to the data acquisition device in a differential form. When the oil flow contains impurities, the impurity molecules and the oil molecules will compete in the electrification process when the oil flow contacts the sensing electrode, so that the mineral oil containing different impurities will generate different voltage signals. By establishing the correlation between the sensor output voltage signal and the impurity attribute, real-time online monitoring of the composition of the mineral oil liquid is realized.

[0043] Figure 4 A flow chart of a method for detecting impurities in oil is provided for the present application. Referring to Figure 4 , it comprises: S101, acquiring a sensing voltage signal output by a sensing electrode.

[0044] S102, acquiring a reference voltage signal output by a reference electrode.

[0045] S103, determining the impurity composition in the mineral oil according to the sensing voltage signal and the reference voltage signal.

[0046] Figure 5 A structure block diagram of an impurity in oil detection device is provided for an embodiment of the present application. Referring to Figure 5 , it comprises: An impurity in oil sensor 10 and a sensor data acquisition module 20.

[0047] Referring to Figure 6 , as an example, the sensor data acquisition module 20 comprises: An interface board 201: used for acquiring the sensing voltage signal and the reference voltage signal output by the impurity in oil sensor 10 and converting them into digital signals.

[0048] An M6Y2C core board 202: mainly used for data recording and analysis.

[0049] A 4G APN board 203: used for communication, including the function of accepting various action codes issued by computer software.

[0050] A power board 204: including an EMC circuit, an AC-DC power module, and a filter circuit, used for providing power supply for other circuits.

[0051] Indicator light module 205: for indicating that the device is working normally. The sensor data acquisition module can realize the acquisition of the sensor output voltage signal, has wired / 4G APN communication function, can realize the integrated application of the mineral oil impurity sensor, and meets the data acquisition demand.

[0052] Referring to Figure 7 The oil circuit and the control module thereof provided by an embodiment of the present application. Comprise: Oil circulation loop 31, oil sample measurement loop 32, oil return unit loop 33, emptying pipeline 34, breathing pipeline 35.

[0053] Oil circulation (take the latest oil sample) loop 31, oil flows through manual valve 301, automatic valve 302, filter 303, oil micro water 1, oil pump 304, pressure sensor 305 in turn, and flows to the oil return port.

[0054] Oil sample measurement (sensor measurement) loop 32: the oil sample flows from the oil inlet to the oil tank 306.

[0055] Oil return (oil sample backfilling) loop 33: the oil sample flows from the bottom of the oil tank 306 to the oil return port.

[0056] The oil sample flows into the oil tank 306 through the upper part of the oil tank 306, a liquid level detection sensor is arranged in the oil tank 306, and the oil tank input is stopped when the specified liquid level is reached, and the oil discharge (oil return) process is started.

[0057] In order to ensure the safe and stable operation of the equipment, the following designs are made for the device: an alarm liquid level is designed for the oil tank, which alarms when the oil is abnormal, and the system stops working to prevent excessive oil from causing component damage or oil leakage. An oil tank built-in pressure sensor is designed to monitor the oil tank pressure in real time, and the system stops working when it is abnormal. The inlet pipeline is provided with a filter screen to filter particulate matter and prevent damage to the downstream components. The return pipeline is provided with a pressure sensor to detect the pressure of the oil return port to prevent abnormal pressure from causing equipment damage. The oil tank discharge pipeline 34 and the breathing pipeline 35 form a two-way channel, the breathing and emptying are connected to the one-way valve 307, the breathing port is provided with a drying module to prevent external gas humidity from interfering with the internal oil sample. The oil inlet and the oil return port are provided with an oil inlet mark and an oil return mark, which facilitates the connection of the oil sample.

[0058] The oil pump 304 of the oil circuit and the control module thereof is preferably a self-suction gear oil pump, the working frequency of which is 0.5Hz (which can be adjusted according to the test, 0.5Hz-2Hz), and the pump speed is 400mL / min-1300mL / min; the oil tank can store 1.5L of oil, and the maximum running time is 2-3min.

[0059] For Figure 7The oil circuit and its control module in the oil circuit are connected with the oil inlet and the oil return through a bypass, so that the impurity detection can be realized.

[0060] Referring to Figure 8 Further, the connection mode of the oil impurity detection device 100 and the transformer 41 is shown. The oil impurity detection device 100 is connected with the transformer 41 through flanges 401 through oil inlet and outlet pipelines 402 and 403.

[0061] The power supply 42 is electrically connected with the oil impurity detection device 100 through a cable 404.

[0062] The specific steps include: connecting the cable 404, and closing the power supply 42 after the test is correct; closing all valves of the flange 401 of the transformer 41, then disassembling the flange blind plate, installing the customized flange plate according to the original position, connecting the oil inlet and outlet pipelines 403, then slowly opening the valve corresponding to the oil outlet flange, using gravity to discharge the internal air, and connecting the pipeline with the oil inlet of the equipment after the oil is discharged; opening the equipment, discharging the internal air of the equipment; at the same time, discharging the air in the oil return pipe, and then connecting the oil return pipe.

[0063] After the above steps are completed, the starting code is input through the background computer, the device starts the oil sample measurement loop to measure the oil sample, and the oil circulation loop can be started at the same time to realize real-time monitoring. At this time, the sensor will output a voltage signal reflecting the impurity properties in the oil, and the background will realize in-situ detection of impurities in mineral oil according to the signal characteristics and the correlation between the calibrated impurity properties and the voltage signal.

[0064] Finally, it should be noted that the present application has the following advantages: 1) in-situ monitoring: the in-situ detection of impurities in mineral oil can improve the timeliness of sampling and analysis by more than 90%; 2) sensitivity: the friction electric sensor combined with the friction sensitive coating has a detection lower limit of 10 ug / mL for micro water and other impurities in the oil; 3) reliability: the anti-interference and sealing design of the specific sensor interface of the oil impurity can reduce external interference; 4) applicability: no constant temperature room is needed, and it is suitable for mineral oil condition monitoring of oil-immersed high-voltage power distribution equipment and aviation / aerospace engines.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can modify the technical solutions described in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An oil impurity sensor characterized by comprising: The oil impurity sensor comprises: a sensing electrode and a reference electrode, which are configured to at least allow oil to flow over surfaces thereof; wherein the sensing electrode is configured to generate a sensing voltage signal by being electrified by oil-solid contact with the oil, and the reference electrode is configured to generate a reference voltage signal by being in contact with the oil; the sensing electrode is formed of an oleophobic material, and the reference electrode is formed of an oleophilic material.

2. The oil-borne contaminant sensor of claim 1, wherein, The sensing electrode comprises a laminated electrode layer, a substrate layer and an oleophobic coating layer.

3. The oil-borne contaminant sensor of claim 1, wherein, The reference electrode comprises a laminated electrode layer and a substrate layer.

4. The oil-borne contaminant sensor of claim 2 or 3, wherein, The oleophobic coating layer has a mineral static contact angle greater than 120 DEG C.

5. The oil-borne contaminant sensor of claim 2 or 3, wherein, The oleophobic coating layer is obtained by spraying an oleophobic coating material, and the oleophobic coating material comprises a PTFE nanoparticle aqueous solution.

6. The oil-borne contaminant sensor of claim 2 or 3, wherein, The substrate layer comprises a polydimethylsiloxane layer.

7. The oil-borne contaminant sensor of claim 2 or 3, wherein, The thickness of the oleophobic coating layer is 200-400 mu m.

8. The oil-borne contaminant sensor of any one of claims 1 to 3, wherein, The oil impurity sensor further comprises: a first cover plate, an oil passage cavity, a second cover plate and a jack plug; wherein the first cover plate, the oil passage cavity and the second cover plate form a closed cavity; the oil passage cavity is provided with an oil inlet and an oil outlet on a side surface thereof; the sensing electrode is arranged on an inner surface of the first cover plate, and the reference electrode is arranged on an inner surface of the second cover plate; the jack plug is used to lead out signals collected by the sensing electrode and the reference electrode.

9. A method for detecting impurities in oil, characterized by, The method is applied to the oil impurity sensor according to any one of claims 1 to 8, and comprises: obtaining a sensing voltage signal output by the sensing electrode; obtaining a reference voltage signal output by the reference electrode; determining an impurity component in the mineral oil according to the sensing voltage signal and the reference voltage signal.

10. An apparatus for detecting impurities in oil, characterized by comprising: The oil impurity sensor according to any one of claims 1 to 8.

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