An integrated sensor system for selective monitoring of particulate matter in lubricating oil

Abstract

The application discloses an integrated sensor system for selectively monitoring particulate matters in lubricating oil, and belongs to the technical field of sensors.The integrated sensor system comprises at least four groups of triboelectric sensors with different coatings, including a triboelectric sensor with a strong magnetic particle response coating, a triboelectric sensor with a weak magnetic particle response coating, a triboelectric sensor with a non-magnetic oil-repellent coating, and a triboelectric sensor without surface treatment; an energy storage module; a signal processing module; and a user control module.The integrated sensor system defined in the application adopts multiple groups of triboelectric sensors, is optimally designed for different particulate matters in lubricating oil, and performs data integration and analysis through the signal processing module; wherein the surface of the triboelectric sensor is specially designed to enhance the detection capability of magnetic particles, so that the integrated sensor system can distinguish between magnetic and non-magnetic particles and identify particles with different magnetism; the user control end is responsible for displaying real-time detection results and controlling the sensor system; in addition, the signal acquisition and processing algorithm and the alarm mechanism of the system realize real-time monitoring and early warning of magnetic particles in lubricating oil, and improve the automation and intelligent level of monitoring.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of sensors, and particularly relates to an integrated sensor system for selectively monitoring particulate matter in lubricating oil. BACKGROUND

[0002] In industrial production, lubricating oil is a key factor to ensure the normal operation of equipment, and its quality is directly related to the stability and service life of the equipment. Contaminants in lubricating oil, such as metal abrasives, carbon deposits and dust, are important indicators of equipment wear and external pollution. The particulate matter contaminants in the lubricating oil cause great harm to the equipment, as they can enter the internal lubrication system, causing abrasive wear, metal indentation and scratch, metal fatigue and other problems. Particulate matter can be generated during equipment operation, such as fine metal particles, and the size of fine particulate matter is generally tens to hundreds of microns.

[0003] These particles have a certain hardness and are small enough to pass through the gap between parts, circulating inside the equipment and causing continuous wear. Particle wear increases the metal powder content in the oil, which further wears the equipment and can cause damage to the equipment such as bearings, causing noise, vibration or increased energy consumption, and even frequent shutdowns and replacement of parts, which has a serious impact on production efficiency and safety. In addition, wear particles can also affect the overall performance of the system, and particles can clog the lubrication system, limiting the flow of lubricating oil, thereby increasing friction and heat generation, further accelerating the wear process. Moreover, these particles can also damage seals and filters, leading to lubricating oil contamination.

[0004] Current methods for monitoring oil particulate matter mainly fall into two categories: offline monitoring and online monitoring. Offline monitoring involves collecting oil samples and sending them to a laboratory for testing and analysis. Offline monitoring mainly uses ferrography and spectroscopy. However, since offline methods require sample collection for analysis, they are not suitable for real-time monitoring of machine operating conditions. Online monitoring technology is mainly achieved through optical, ultrasonic, capacitive, inductive, electromagnetic and other methods. The presence of abrasive particles significantly changes the dielectric constant, magnetic permeability, electrical conductivity and optical properties of lubricating oil, and online monitoring technology detects the corresponding characteristic information to detect particulate matter. Although existing monitoring technologies can provide some information about the state of lubricating oil to some extent, they often have problems such as low monitoring accuracy, inability to achieve continuous real-time monitoring, inability of sensors to selectively detect particulate matter, and insufficient intelligence level.

[0005] Therefore, there is an urgent need to develop a sensor system that can accurately monitor particulate contaminants, which can further promote the development of lubricating oil monitoring technology and improve monitoring accuracy and efficiency. SUMMARY

[0006] In view of the above technical problems, the application provides an integrated sensor system for selectively monitoring particulate matters in lubricating oil.

[0007] To achieve the above object, the application provides the following technical scheme.

[0008] An integrated sensor system for selectively monitoring particulate matters in lubricating oil comprises:

[0009] At least four groups of triboelectric sensors with different coatings, including a triboelectric sensor with a strong magnetic particle response coating, a triboelectric sensor with a weak magnetic particle response coating, a triboelectric sensor with a non-magnetic oil-repellent coating, and a triboelectric sensor without any surface treatment.

[0010] An energy storage module for storing the electric energy generated by the triboelectric sensors.

[0011] A signal processing module for integrating signals from the triboelectric sensors and processing the signals through a signal processing algorithm.

[0012] A user control module including a user interface for converting the electric signals obtained by the signal processing module into an output current for displaying real-time detection results of magnetic particles in the lubricating oil, and for controlling different modules of the integrated sensor system.

[0013] Beneficial effects: The integrated sensor system defined in the application adopts multiple groups of triboelectric sensors, which are optimally designed for different particulate matters in the lubricating oil and are subjected to data integration and analysis through a signal processing module. The surface of the triboelectric sensor is specially designed to enhance the detection capability of magnetic particles, including a magnetic surface, an unmodified surface, and an oil-repellent surface. In addition, the triboelectric sensor disclosed in the application can distinguish between magnetic and non-magnetic particles and identify particles with different magnetism. The user control module is responsible for displaying real-time detection results and controlling the sensor system. That is, the integrated sensor system of the application realizes real-time monitoring and early warning of magnetic particles in the lubricating oil through a signal acquisition and processing algorithm and an alarm mechanism, thereby improving the automation and intelligent level of monitoring.

[0014] Optionally, according to the magnetic strength of the surface coating of the triboelectric sensor, the triboelectric sensors with different coatings are integrated into a triboelectric sensor array.

[0015] The triboelectric sensor array includes a triboelectric sensor with a strong magnetic particle response coating and a triboelectric sensor with a weak magnetic particle response coating, so as to divide the lubricating oil into a strong magnetic region and a weak magnetic region.

[0016] Optionally, the triboelectric sensor without any surface treatment includes an electrode layer and a friction layer.

[0017] Further, the material of the electrode layer is selected from at least one of gold, silver, aluminum, copper, titanium, chromium, selenium, iron, manganese, platinum, nickel, palladium, copper alloy or aluminum alloy.

[0018] Further, the material of the friction layer is selected from at least one of polydimethylsiloxane, polyethylene, polypropylene, polyvinylidene fluoride, perfluoroethylene propylene, vinylidene fluoride-acrylonitrile copolymer, polytetrafluoroethylene, polyvinyl chloride, polytrifluorochloroethylene, polychlorobutadiene, polyisobutylene, polyformaldehyde, polyamide or polyimide.

[0019] Optionally, the preparation process of the triboelectric sensor with the strong magnetic particle response coating and the triboelectric sensor with the weak magnetic particle response coating is as follows:

[0020] The surfactant and fluorine-containing silane are added into the dispersion liquid containing the magnetic nanoparticles to form an aqueous solution, which is then sprayed on the surface of the triboelectric sensor and dried to form a magnetic particle response coating, thereby obtaining the triboelectric sensor with the oleophobic and magnetic particle response coating.

[0021] Further, the roughness of the surface with the oleophobic and magnetic particle response coating is 3-5 μm, and the thickness of the coating is 5-15 μm.

[0022] Further, the magnetic nanoparticles include at least one of ferroferric oxide particles, ferromanganic oxide particles, composite metal graphene particles, composite metal oxide particles or composite carbon nanotubes, and the particle size is 10-100 nm.

[0023] Optionally, when the coating has a strong magnetic particle response, the mass ratio of the magnetic nanoparticles to water in the dispersion liquid containing the magnetic nanoparticles is 1:20-30, and the spraying frequency is 6 times.

[0024] When the coating has a weak magnetic particle response, the mass ratio of the magnetic nanoparticles to water in the dispersion liquid containing the magnetic nanoparticles is 1:35-45, and the spraying frequency is 4 times.

[0025] The present application can distinguish the strong and weak magnetism by controlling the different concentrations and different spraying frequencies of the dispersion liquid containing the magnetic nanoparticles.

[0026] Further, the surfactant is an anionic fluorocarbon surfactant; and / or

[0027] The fluorine-containing silane is selected from at least one of (3,3,3-trifluoropropyl)methyl dichlorosilane, (3,3,3-trifluoropropyl)methyl dimethoxysilane, (3,3,3-trifluoropropyl)methyl diethoxysilane, 1,3,5-trimethyl-1,3,5-tris(3,3,3-trifluoropropyl)-cyclotrisiloxane, (3,3,3-trifluoropropyl)trimethoxysilane, heptadecafluorodecyltriethoxysilane, tridecafluorooctyltriethoxysilane, trifluoromethyltrimethylsilane, or 1H,1H,2H,2H-perfluorodecyltriethoxysilane.

[0028] Further, the mass ratio of the anionic fluorocarbon surfactant and the fluorine-containing silane is (4-7) g: 10 mg.

[0029] Optionally, the preparation process of the triboelectric sensor with a non-magnetic oleophobic coating is as follows:

[0030] Spraying an aqueous solution containing nanoparticles and a surfactant on the surface of the triboelectric sensor to obtain a triboelectric sensor with a non-magnetic oleophobic coating.

[0031] Further, the nanoparticles are selected from at least one of silica nanoparticles, titanium dioxide particles, polystyrene nanoparticles, carbon nanotubes, or composite graphene particles; wherein the particle size of the nanoparticles is 20-100 nm.

[0032] Further, in the aqueous solution, the mass ratio of the nanoparticles and water is 1:30-40.

[0033] Optionally, the signal processing algorithm includes at least one of empirical mode decomposition, wavelet change, low-pass / high-pass filtering, or a machine learning algorithm.

[0034] Optionally, the user control module further includes an alarm module, which is automatically started when the output current is less than a preset threshold, so that the staff can maintain the machine and replace the new lubricating oil.

[0035] Compared with the prior art, the integrated sensor system for selectively monitoring particulate matter in lubricating oil has the following advantages and technical effects:

[0036] 1. High detection accuracy and self-power supply capability: By using different friction materials and electrode designs, the monitoring sensitivity of magnetic particles in the lubricating oil is improved; the sensor system is provided with an energy storage module to realize self-power supply, thereby reducing the dependence on external power supply and improving the stability and practicality of the system.

[0037] 2. Selective identification of particulate matter: Different surface designs can selectively monitor non-magnetic particles, magnetic particles (including magnetic particles with different magnetism).

[0038] 3. Real-time monitoring and early warning: The integrated signal recognition module can analyze the content of magnetic particles in lubricating oil in real time, and display the real-time detection results through the user interface, improving the automation and intelligence level of monitoring. BRIEF DESCRIPTION OF DRAWINGS

[0039] The accompanying drawings, which form a part of this description, illustrate the present application and serve to explain the principles of the present application. The present description along with the accompanying drawings make known the exemplary embodiments of the present application. In the drawings:

[0040] Figure 1 A schematic diagram of a triboelectric sensor with a magnetic particle responsive coating in Example 1 of the present application;

[0041] Figure 2 A distribution diagram of four groups of triboelectric sensors with different surface characteristic coatings in Example 1 of the present application;

[0042] Figure 3 A distribution diagram of four groups of triboelectric sensors with different surface characteristic coatings in Example 2 of the present application;

[0043] Figure 4 A signal output result diagram of the integrated sensor system in Example 1 of the present application at different concentrations of particulate matter;

[0044] Wherein, the left graph is 10 μg / mL, and the right graph is 50 μg / mL;

[0045] Figure 5 A workflow diagram of an integrated sensor system for selectively monitoring particulate matter in lubricating oil according to the present application;

[0046] Figure 6 A structural diagram of an integrated sensor system for selectively monitoring particulate matter in lubricating oil according to the present application;

[0047] Wherein, 1- at least four groups of triboelectric sensors containing different coatings; 2- energy storage module; 3- signal processing module; 4- user control module; 5- user interface; 6- alarm module. DETAILED DESCRIPTION

[0048] The various illustrative embodiments of the present application will now be described in detail in connection with the accompanying drawings. This description is made for illustrative purposes only and is not intended to limit the scope of the present application.

[0049] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. Additionally, for a range of values of, an intermediate value of the upper limit and the lower limit of the range is specifically disclosed. Each smaller range between any stated value or inferred value and any other stated value or inferred value in the stated range is also specifically disclosed. The upper and lower limits of these smaller ranges can independently be included or excluded in the ranges.

[0050] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Although preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application. All documents mentioned herein are incorporated by reference to disclose and describe in full the methods and / or materials which are described therein. In the case of conflict between the present specification and any document incorporated by reference, the present specification controls.

[0051] Many modifications and variations of the present application described in the specific embodiments of the application can be made by those skilled in the art without departing from the spirit or scope of the application. Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application. The specification and examples are illustrative only.

[0052] As used herein, the terms "comprise", "comprising", "include", "including", "have", "having" and the like are open-ended terms that are intended to mean "including but not limited to".

[0053] The embodiments of the present application provide an integrated sensor system for selectively monitoring particulate matter in lubricating oil, which can be operated stably for a long time, realizes real-time monitoring of magnetic particles in lubricating oil, and has high energy output and self-power supply capability.

[0054] The preparation method of the integrated sensor system comprises the following steps:

[0055] (1) preparing different surface characteristic coatings;

[0056] (2) the designed triboelectric sensor monitors the magnetic particles in the lubricating oil;

[0057] (3) constructing an integrated sensor system for selectively monitoring particulate matter in lubricating oil;

[0058] In step (1), a magnetic coating is prepared:

[0059] A nano-magnetic material with suitable magnetic properties is selected, with a particle size of 10-100 nm; the nano-magnetic particles include but are not limited to ferroferric oxide particles, manganese tetroxide particles, composite metal graphene particles, composite metal oxide particles, and composite carbon nanotubes;

[0060] The magnetic nano-particles are dispersed in deionized water at a mass ratio of 1:10-40 to form a dispersion liquid containing magnetic nano-particles;

[0061] Under stirring conditions, the anionic fluorocarbon surfactant and the fluorine-containing silane are dissolved in the dispersion liquid containing magnetic nano-particles, and stirring is continued for 30-60 minutes to form a uniform aqueous solution;

[0062] The aqueous solution is sprayed on the triboelectric sensor surface and dried in air, and the spraying process is repeated to form a magnetic nano-sensing coating;

[0063] to obtain a magnetic coating with oleophobicity;

[0064] In some optional embodiments, the fluorine-containing silane includes but is not limited to (3,3,3-trifluoropropyl)methyl dichlorosilane, (3,3,3-trifluoropropyl)methyl dimethoxysilane, (3,3,3-trifluoropropyl)methyl diethoxysilane, 1,3,5-trimethyl-1,3,5-tris(3,3,3-trifluoropropyl)-cyclotrisiloxane, (3,3,3-trifluoropropyl)trimethoxysilane, heptadecafluorodecyltriethoxysilane, tridecafluorooctyltriethoxysilane, trifluoromethyltrimethylsilane, or 1H,1H,2H,2H-perfluorodecyltriethoxysilane.

[0065] In some optional embodiments, the surface roughness of the magnetic coating with oleophobicity is controlled at 3-5 μm, and the coating thickness is 5-15 μm, to optimize the adsorption capacity of the sensor to the magnetic particles and the generation of electrical signals.

[0066] In step (1), a non-magnetic oleophobic coating is prepared:

[0067] The nano-particles are dispersed in deionized water at a mass ratio of 1:30-40; the nano-particle size is 20-100 nm;

[0068] Under stirring conditions, the anionic fluorocarbon surfactant is dissolved in the solution containing nano-particles, and stirring is continued to form an aqueous solution, with stirring for 30-60 minutes;

[0069] The aqueous solution is sprayed on the triboelectric sensor surface and dried in air, and the spraying process is repeated to form a non-magnetic oleophobic coating;

[0070] In some alternative embodiments, the nanoparticles include, but are not limited to, silica nanoparticles, titanium dioxide particles, polystyrene nanoparticles, carbon nanotubes, composite graphene particles.

[0071] In step (2), the triboelectric sensor with different surface coating includes an electrode layer, a triboelectric layer, and a coating.

[0072] In some alternative embodiments, the electrode material includes, but is not limited to, gold, silver, aluminum, copper, titanium, chromium, selenium, iron, manganese, platinum, nickel, palladium, copper alloy, or aluminum alloy.

[0073] In some alternative embodiments, the triboelectric layer material includes, but is not limited to, polydimethylsiloxane, polyethylene, polypropylene, polyvinylidene fluoride, perfluoroethylene propylene, vinylidene fluoride-acrylonitrile copolymer, polytetrafluoroethylene, polyvinyl chloride, polychlorotrifluoroethylene, polychloroprene, polyisobutylene, polyformaldehyde, polyamide, or polyimide.

[0074] In some alternative embodiments, the coating includes, but is not limited to, different magnetic strength coatings, only oleophobic surface coatings, composite coatings, or combined coatings.

[0075] In some alternative embodiments, the triboelectric sensor (without any surface treatment) is composed of a sheet-shaped triboelectric layer and a sheet-shaped electrode, with one end of the electrode grounded, forming a triboelectric sensor that generates an electric current signal based on the triboelectric effect and electrostatic induction principle.

[0076] The working principle of the multiple triboelectric sensors with different surface coatings is as follows:

[0077] The electrode is partially submerged as the oil rises. According to the electron transfer theory, the polytetrafluoroethylene surface forms bound charges with the oil due to the triboelectric effect. Due to the asymmetric distribution of charges, electron transfer occurs from the grounded end to the electrode, and then from the electrode to the grounded end until the surface is completely submerged in oil.

[0078] Conversely, when the oil falls, the potential distribution changes from the electrode end to the grounded end.

[0079] By using magnetic surface adsorption particles, the magnetic and non-magnetic particles are distinguished through the adsorption capacity of the magnetic nanoparticle layer. Magnetic particles are more easily adsorbed on the surface, causing fluctuations in the electric signal, achieving the purpose of monitoring.

[0080] By using the adsorption capacity of the magnetic nanoparticle layer with different surface designs, strong and weak magnetic particles are distinguished. Strong and weak magnetic particles have different adsorption properties and effects on different magnetic surfaces, and different magnetic surface sensors produce different signal fluctuations, achieving selective detection.

[0081] To detect magnetic particles, the current of the triboelectric sensor under different magnetic particle content is measured.

[0082] As the content of magnetic particles increases, the current output signal decreases. When magnetic particles first appear in the oil, the triboelectric sensor can detect that the contaminant is a magnetic particle.

[0083] In step (3), the integrated sensor system for selective monitoring of lubricating oil particulate matter includes at least 4 sets of triboelectric sensors (i.e., oil-repellent surfaces with strong and weak magnetic particle responses, no ferromagnetic particle responses, and no surface treatment), an energy storage module, a signal processing module, and a user control module.

[0084] The signal processing module is used to integrate signals from various groups of triboelectric sensors and perform signal processing through signal processing algorithms.

[0085] Signal processing algorithms include, but are not limited to, empirical mode decomposition, wavelet transform, low-pass / high-pass filtering, and machine learning algorithms.

[0086] The user control module includes a user interface for displaying real-time detection results of magnetic particles in the lubricating oil, as well as controlling different modules of the integrated sensor.

[0087] The integrated sensor system transmits the generated current signal to the user's computer terminal, and the current signal of pollutant content under various operating conditions is obtained through pre-testing.

[0088] Based on the current or composition change trend, the system provides early warning of the particle state in the lubricating oil. When the current is less than the preset threshold, the alarm system is automatically activated, and the staff can then maintain the machine and replace the lubricating oil.

[0089] All raw materials used in this invention were purchased commercially. The fluorinated silanes used in the following examples were purchased from Aladdin, specifically 1H,1H,2H,2H-perfluorodecyltriethoxysilane, with the molecular formula: C1H,1H,2H,2H-perfluorodecyltriethoxysilane. 16 F 17 H 19 O3Si, molecular weight: 610.38.

[0090] It should be noted that technologies not described in detail in the embodiments of the present invention, such as signal processing modules, user control modules, user computer terminals, energy storage modules, alarm modules, etc., can all be achieved using conventional methods in the prior art and are not key points of the invention. They will not be elaborated upon in the embodiments.

[0091] The technical solution of the present invention will be further illustrated by the following embodiments.

[0092] Example 1

[0093] like Figure 6As shown, an integrated sensor system for selective monitoring of particulate matter in lubricating oil includes four groups of triboelectric sensors 1 (i.e. with strong magnetic particle response, with weak magnetic particle response, with non-magnetic oleophobic coating, without any treatment surface), an energy storage module 2, a signal processing module 3 and a user control module 4; the user control module 4 further includes a user interface 5 and an alarm module 6;

[0094] The preparation process of the four groups of triboelectric sensors with different surface characteristic coatings is as follows:

[0095] (1) Triboelectric sensor without any treatment surface

[0096] The triboelectric sensor is composed of a sheet-shaped copper electrode and a sheet-shaped polytetrafluoroethylene rubbing layer; the electrode and rubbing layer materials of the following three groups of triboelectric sensors with different characteristic coatings are the same as this group;

[0097] (2) Triboelectric sensor with strong magnetic particle response coating

[0098] Magnetic nano-magnetic material magnetite particles with magnetic properties are selected, with a particle size of 25 nm;

[0099] By dispersing 1 g of magnetic nano-particles in 30 g of deionized water, a dispersion liquid containing magnetic nano-particles is formed;

[0100] Under stirring conditions, 6 g of anionic fluorocarbon surfactant (Capstone FS-61) and 10 mg of fluorine-containing silane are dissolved in the above dispersion liquid containing magnetic nano-particles, and stirring is continued for 30 minutes to form a uniform aqueous dispersion liquid;

[0101] Then the above aqueous dispersion liquid is sprayed on the surface of the triboelectric sensor and dried in air, and the spraying process is repeated 6 times to form a magnetic nano-sensing coating;

[0102] The roughness of the coating surface is 5 μm, and the coating thickness is 10 μm;

[0103] (3) Triboelectric sensor with weak magnetic particle response coating

[0104] Magnetic nano-magnetic material magnetite particles with magnetic properties are selected, with a particle size of 25 nm;

[0105] By dispersing 1 g of magnetic nano-particles in 40 g of deionized water, a dispersion liquid containing magnetic nano-particles is formed;

[0106] Under stirring conditions, 6 g of anionic fluorocarbon surfactant (Capstone FS-61) and 10 mg of fluorine-containing silane are dissolved in the above dispersion liquid containing magnetic nano-particles, and stirring is continued for 30 minutes to form a uniform aqueous solution;

[0107] The aqueous solution is then sprayed on the triboelectric sensor surface and dried in air, and the spraying process is repeated 4 times to form a magnetic nano-sensing coating;

[0108] The roughness of the coating surface is 4 pm, and the coating thickness is 10 pm;

[0109] (4) Triboelectric sensor with non-magnetic oleophobic coating

[0110] 1 g of silica nanoparticles is dispersed in 30 g of deionized water; the particle size of the nanoparticles is 25 nm;

[0111] Under stirring conditions, the anionic fluorocarbon surfactant (Capstone FS-61) is dissolved in the nanoparticle-containing solution, and the ratio of the anionic fluorocarbon surfactant to the nanoparticles is 1:15, and the stirring is continued to form an aqueous solution, and the stirring is continued for 60 minutes;

[0112] The aqueous solution is then sprayed on the triboelectric sensor surface and dried in air, and the spraying process is repeated 4 times to form a nano-oleophobic coating, and the roughness of the coating surface is 5 pm, and the coating thickness is 10 pm.

[0113] The working principle of the integrated sensor system of the present embodiment is as follows:

[0114] As shown in Figure 2 The four groups of triboelectric sensors prepared above are inserted into the lubricating oil (a cuboid type solid container), and are arranged according to different coatings, and then the strong magnetic region and the weak magnetic region are distinguished in the lubricating oil, wherein the triboelectric sensors of the (2) group and the (4) group are located in the strong magnetic region; the triboelectric sensors of the (3) group and the (1) group are located in the weak magnetic region;

[0115] Then one end of the copper electrode is grounded, and an electric current signal is generated based on the principle of triboelectricity and electrostatic induction;

[0116] The electrode is partially submerged as the oil rises, and according to the electron transfer theory, the polytetrafluoroethylene surface forms bound charges due to the triboelectric effect; due to the asymmetric distribution of charges, the electrode and the free electrons of the ground end transfer from the ground end to the electrode, until the surface is completely submerged by the oil;

[0117] On the contrary, when the oil falls, the potential distribution changes from the electrode end to the ground end;

[0118] The magnetic surface adsorbs particles, and by the adsorption capacity of the magnetic nanoparticle layer, magnetic and non-magnetic particles are distinguished, and magnetic particles are more easily adsorbed on the surface, causing fluctuations in the electrical signal, achieving the purpose of monitoring;

[0119] The adsorption capacity of the magnetic nano-layer with different surface designs is used to distinguish between strong and weak magnetic particles. Strong and weak magnetic particles have different adsorption properties and effects on different magnetic surfaces, and different magnetic surface sensors produce different signal fluctuations, enabling selective detection.

[0120] To detect magnetic particles, the output current of the triboelectric sensor is measured under different magnetic particle content;

[0121] As the content of magnetic particles increases, the current output signal decreases, and the triboelectric sensor can monitor the presence of magnetic particles in the oil;

[0122] The signal processing module is used to integrate signals from each group of triboelectric sensors and process signals using machine learning algorithms.

[0123] The user control module includes a user interface for displaying real-time detection results of magnetic particles in lubricating oil and controlling different modules of the integrated sensor.

[0124] The integrated sensor system transmits the generated current signal to the user computer terminal, and through pre-test, the current signal of each working condition is obtained. Figure 4 as shown;

[0125] According to the current or component variation trend, a warning is given for the state of particles in the lubricating oil. When the current is less than the preset threshold, the alarm system automatically starts, and the staff maintains the machine and replaces the new lubricating oil. The overall workflow is shown in Figure 5 .

[0126] Example 2

[0127] An integrated sensor system for selectively monitoring particles in lubricating oil,

[0128] The difference between this example and Example 1 is that the preparation process of the four groups of triboelectric sensors is different.

[0129] In this example, the preparation process of the four groups of triboelectric sensors with different surface characteristics is as follows:

[0130] (1) Triboelectric sensor without any treatment

[0131] The triboelectric sensor is composed of a sheet-shaped aluminum electrode and a sheet-shaped polyimide rubbing layer. The electrode and rubbing layer materials of the following three groups of coated triboelectric sensors are the same as this group.

[0132] (2) Triboelectric sensor with strong magnetic particle response coating

[0133] The selected magnetic nanomaterial is manganese tetroxide with a particle size of 40 nm.

[0134] An aqueous solution was formed by dispersing 1g of magnetic nanoparticles in 30g of deionized water;

[0135] Under stirring conditions, anionic fluorocarbon surfactant (Capstone FS-61) and 10 mg of fluorosilane were dissolved in a solution containing nanoparticles, and the mixture was stirred for 35 minutes to form a homogeneous aqueous solution.

[0136] The aqueous solution was sprayed onto the surface of the triboelectric sensor and dried in air. The spraying was repeated 6 times to form a magnetic nanosensing coating.

[0137] The surface roughness of the coating is 5 μm, and the coating thickness is 10 μm.

[0138] (3) Triboelectric sensor with weakly magnetic particle-responsive coating

[0139] The selected magnetic nanomaterial is manganese tetroxide with a particle size of 40 nm.

[0140] An aqueous solution was formed by dispersing 1g of magnetic nanoparticles in 40g of deionized water;

[0141] Under stirring conditions, anionic fluorocarbon surfactant (Capstone FS-61) and 10 mg of fluorosilane were dissolved in a solution containing nanoparticles, and the mixture was stirred for 35 minutes to form a homogeneous aqueous solution.

[0142] The aqueous solution was sprayed onto the surface of the triboelectric sensor and dried in air. The spraying process was repeated four times to form a weakly magnetic nanosensing coating.

[0143] The surface roughness of the coating is 4 μm, and the coating thickness is 10 μm;

[0144] (4) Triboelectric sensor with non-magnetic oleophobic coating

[0145] 1g of silica nanoparticles were dispersed in 30g of deionized water; the nanoparticle size was 40nm.

[0146] Under stirring conditions, anionic fluorocarbon surfactant (Capstone FS-61) was dissolved in a solution containing nanoparticles at a mass ratio of 1:15, and the mixture was continuously stirred to form an aqueous solution for 30 minutes.

[0147] The aqueous solution is sprayed onto the surface of the triboelectric sensing device and dried in air. The spraying process is repeated to form a nano-oleophobic coating with a surface roughness of 5 μm and a coating thickness of 10 μm.

[0148] The working principle of the integrated sensor system of the present embodiment is as follows:

[0149] As shown in Figure 3 The four groups of triboelectric sensors prepared above are inserted into the lubricating oil (pipeline), and are arranged according to different coatings, so as to distinguish strong magnetic and weak magnetic zones in the lubricating oil, wherein the triboelectric sensors of the (2)th group and the (4)th group are located in the strong magnetic zone; the triboelectric sensors of the (3)th group and the (1)th group are located in the weak magnetic zone;

[0150] Then one end of the aluminum electrode is grounded, and an electric current signal is generated based on the principle of triboelectricity and electrostatic induction;

[0151] The electrode is partially submerged when it contacts the oil. According to the electron transfer theory, the polyimide surface forms bound charges due to the triboelectric effect with the oil. Due to the asymmetric distribution of charges, electron transfer occurs from the grounded end to the electrode, and from the electrode end to the grounded end until the surface is completely submerged in oil.

[0152] On the contrary, when the oil flows, the potential distribution changes from the electrode end to the grounded end.

[0153] Magnetic particles are adsorbed on the surface by using a magnetic surface. By the adsorption capacity of the magnetic nanoparticle layer, magnetic and non-magnetic particles are distinguished. Magnetic particles are more easily adsorbed on the surface, causing fluctuations in the electrical signal, achieving the purpose of monitoring.

[0154] By the adsorption capacity of the magnetic nanoparticle layer designed on different surfaces, strong and weak magnetic particles are distinguished. Strong and weak magnetic particles have different adsorption properties and effects on different magnetic surfaces. Different magnetic surface sensors produce different signal fluctuations, achieving selective detection.

[0155] To detect magnetic particles, the current signal of the triboelectric sensor under different magnetic particle content is measured.

[0156] As the content of magnetic particles increases, the current output signal decreases. When magnetic particles appear in the oil, the triboelectric sensor can monitor the contamination of magnetic particles.

[0157] The signal processing module is used to integrate signals from each group of triboelectric sensors and process signals using machine learning algorithms.

[0158] The user control module includes a user interface for displaying real-time detection results of magnetic particles in the lubricating oil and controlling different modules of the integrated sensor.

[0159] The integrated sensor system transmits the generated current signal to the user computer terminal, and through pre-test, the current signal of each working condition is obtained.

[0160] According to the current or component variation trend, the state of particles in the lubricating oil is warned, when the current is less than the preset threshold, the alarm system is automatically started, the staff maintains the machine and replaces the new lubricating oil, and the overall working process is as shown in Figure 5

[0161] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.​

Claims

1. An integrated sensor system for selectively monitoring particulate matter in lubricating oil, characterized in that, include: At least four sets of triboelectric sensors containing different coatings are included, including triboelectric sensors with a strongly magnetic particle-responsive coating, triboelectric sensors with a weakly magnetic particle-responsive coating, triboelectric sensors with a non-magnetic oleophobic coating, and triboelectric sensors without surface treatment; the fabrication processes of the triboelectric sensors with the strongly magnetic particle-responsive coating and the triboelectric sensors with the weakly magnetic particle-responsive coating are both as follows: A surfactant and a fluorinated silane are added to a dispersion containing magnetic nanoparticles to form an aqueous solution, which is then sprayed onto the surface of a triboelectric sensor and dried to form a magnetic particle responsive coating, resulting in a triboelectric sensor that is oleophobic and has a magnetic particle responsive coating. When the coating has a strong magnetic particle response, the mass ratio of magnetic nanoparticles to water in the dispersion containing magnetic nanoparticles is 1:20-30, and the number of spraying times is 6. When the coating has a weak magnetic particle response, the mass ratio of magnetic nanoparticles to water in the dispersion containing magnetic nanoparticles is 1:35-45, and the number of spraying times is 4. The surfactant is an anionic fluorocarbon surfactant; The fluorinated silane is selected from at least one of (3,3,3-trifluoropropyl)methyldichlorosilane, (3,3,3-trifluoropropyl)methyldimethoxysilane, (3,3,3-trifluoropropyl)methyldiethoxysilane, 1,3,5-trimethyl-1,3,5-tris(3,3,3-trifluoropropyl)-cyclotrisiloxane, (3,3,3-trifluoropropyl)trimethoxysilane, perfluorodecyltrimethoxysilane, heptadecyltriethoxysilane, tridecafluorooctyltriethoxysilane, trifluoromethyltrimethylsilane, or 1H,1H,2H,2H-perfluorodecyltriethoxysilane. Energy storage module, which stores the electrical energy generated by the triboelectric sensor; The signal processing module is used to integrate signals from the triboelectric sensor and perform signal processing algorithms. The user control module includes a user interface, which converts the electrical signals obtained by the signal processing module into output current to display the real-time detection results of magnetic particles in the lubricating oil; and controls different modules of the integrated sensor system.

2. The integrated sensor system for selectively monitoring particulate matter in lubricating oil according to claim 1, characterized in that, The surface roughness of the oleophobic and magnetically responsive coating is 3-5 μm, and the coating thickness is 5-15 μm.

3. The integrated sensor system for selectively monitoring particulate matter in lubricating oil according to claim 1, characterized in that, The magnetic nanoparticles include at least one of the following: iron oxide particles, manganese oxide particles, composite metal graphene particles, composite metal oxide particles, or composite carbon nanotubes.

4. An integrated sensor system for selectively monitoring particulate matter in lubricating oil according to claim 1, characterized in that, The fabrication process of the triboelectric sensor with a non-magnetic oleophobic coating is as follows: An aqueous solution containing nanoparticles and surfactants is sprayed onto the surface of a triboelectric sensor to obtain a triboelectric sensor with a non-magnetic oleophobic coating.

5. An integrated sensor system for selectively monitoring particulate matter in lubricating oil according to claim 4, characterized in that, The nanoparticles are selected from at least one of silica nanoparticles, titanium dioxide nanoparticles, polystyrene nanoparticles, carbon nanotubes, or composite graphene particles. The nanoparticles have a particle size of 20-100 nm.

6. An integrated sensor system for selectively monitoring particulate matter in lubricating oil according to claim 1, characterized in that, The signal processing algorithm includes at least one of empirical mode decomposition, wavelet transform, low-pass / high-pass filtering, or machine learning algorithm.

7. An integrated sensor system for selectively monitoring particulate matter in lubricating oil according to claim 1, characterized in that, The user control module also includes an alarm module. When the output current is less than a preset threshold, the alarm module is automatically activated, and the staff can perform maintenance on the machine and replace the lubricating oil.

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