Sensor, monitoring system and monitoring method for monitoring leakage of non-conductive oil

Abstract

The invention relates to a sensor, a monitoring system and a monitoring method for monitoring leakage of non-conductive oil. The sensor comprises a conductor which is arranged in the judgment circuit and is made of conductive powder; the judgment circuit judges whether the conductor is electrified or whether the resistance is increased in an electrified state; when the conductive powder is not in contact with the non-conductive oil liquid, the conductor formed by the conductive powder is in a conductive state, and the resistance is not changed; when the conductive powder is in contact with non-conductive oil liquid, the oil liquid is diffused in gaps of the conductive powder due to capillarity, so that the conductor formed by the conductive powder is in a conductive and resistance-increased state or in a non-conductive state. The sensor is simple in structure, and the shape and the size of the sensor can be flexibly designed according to use scenes. Meanwhile, the cost of materials used in the sensor is low. The sensor provided by the invention can be placed at a position where non-conductive oil of industrial equipment or elements is easy to leak, and is used for monitoring whether the problem of oil leakage exists or not.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial sensors, and in particular to a sensor, a monitoring system and a monitoring method for monitoring leakage of non-conductive oil. Background Art

[0002] Industrial equipment is widely used in a variety of oils for fuel, lubrication, transmission, and heat dissipation. Most oils are non-conductive liquids. Oil leakage can cause environmental pollution and equipment failure. Oil leakage is difficult to completely avoid. Therefore, the equipment needs to monitor oil leakage to achieve early detection and early treatment to reduce risks.

[0003] The main methods and shortcomings of existing online monitoring of non-conductive oil leakage are shown in the following table:

[0004] Summary of the invention

[0005] To solve the above problems, the present invention provides a sensor for monitoring non-conductive oil leakage, comprising a conductor formed of conductive powder, which is arranged in a judgment circuit and judged by the judgment circuit whether it is powered on or whether the resistance increases when powered on;

[0006] When not in contact with non-conductive oil, the conductor formed by the conductive powder is in a conductive state with no change in resistance;

[0007] When in contact with non-conductive oil, the conductor formed of the conductive powder is in a conductive state with increased resistance or in a non-conductive state due to a capillary phenomenon.

[0008] Based on the above solution, the conductive powder includes metal powder and / or carbon powder.

[0009] Based on the above scheme, the metal powder is a single metal powder, two or more single metal powders, metal oxide powder and / or alloy powder; the carbon-based powder is at least one of graphite, carbon black, carbon fiber, and graphene.

[0010] Based on the above solution, the particle size of the metal powder is less than 300 μm.

[0011] Based on the above solution, a porous oil-absorbing material layer is provided on the upper part and / or the lower part of the conductor formed by the conductive powder.

[0012] Based on the above solution, the material of the porous oil-absorbing material layer is felt, cloth, sponge, porous plastic, porous metal or porous ceramic.

[0013] On the basis of the above solution, the upper and lower parts of the conductor formed by the conductive powder are both provided with a porous oil-absorbing material layer, and the outside of the sensor is also provided with a shell that allows oil to pass through.

[0014] Based on the above solution, the sum of the thickness of the upper and lower porous oil-absorbing material layers in an uncompressed state plus the thickness of the conductor in an uncompressed state is greater than the height of the cavity inside the shell.

[0015] Based on the above solution, grooves for constraining the conductor formed by the conductive powder are provided on the porous oil-absorbing material layer.

[0016] On the basis of the above scheme, in the uncompressed state, the thickness of the conductor formed by the conductive powder is 0.2mm-2mm, and in the compressed state, the thickness of the conductor formed by the conductive powder is 0.1mm-1.5mm.

[0017] The present application also provides a monitoring system for monitoring non-conductive oil leakage, comprising a judgment circuit and a sensor for monitoring non-conductive oil leakage arranged between two wires of the judgment circuit, wherein the sensor is the above-mentioned sensor;

[0018] When not in contact with non-conductive oil, the conductor of the sensor formed of conductive powder is in a state of being conductive and having no resistance change;

[0019] When contacting with non-conductive oil, the oil diffuses in the gaps of the conductive powder due to the capillary phenomenon, causing the conductor of the sensor formed by the conductive powder to be in a conductive state with increased resistance or in a non-conductive state.

[0020] A method for monitoring non-conductive oil leakage, using the above sensor or the above monitoring system;

[0021] When using:

[0022] (1) When not in contact with non-conductive oil, the conductor formed by the conductive powder is in a conductive state with no change in resistance, and it is judged that the circuit is connected, which is a normal state;

[0023] (2) When there is oil leakage, if the amount of oil leakage is small and not enough to disconnect the conductor formed by the conductive powder, the conductor formed by the conductive powder is in a state where it can conduct electricity and the resistance increases. At this time, the resistance of the judgment circuit increases; as the amount of oil leakage increases, the conductor formed by the conductive powder is in a non-conductive state, and the circuit is judged to be disconnected.

[0024] The sensor of the present invention has a simple structure, and the shape and size of the sensor can be flexibly designed according to the usage scenario. At the same time, the material cost used in the sensor of the present invention is low.

[0025] The working principle of the sensor of the present invention is based on the capillary phenomenon of liquid in a capillary tube. A conductor formed by conductive powder is fixed between two wires of a judgment circuit. Under the action of the conductor, a current path is formed in the judgment circuit. When the leaked non-conductive oil contacts the conductive powder, a capillary phenomenon will occur due to the internal gaps formed by the conductive powder. The non-conductive oil will diffuse between the conductive powder particles and outside the powder, diluting the conductive powder, thereby increasing the resistance of the conductor. As the leaked oil increases, a larger space will be formed between the conductive powder particles, eventually making the conductive powder loose and unable to maintain a conductive state, thereby determining that the circuit of the judgment circuit determination system is disconnected.

[0026] At the same time, the setting of the porous oil-absorbing material layer in the sensor not only forms a certain constraint and fixing effect on the conductor of the sensor, but also accelerates the diffusion and loosening effect of the oil on the conductive powder, effectively improving the sensitivity of the sensor.

[0027] The sensor of the present invention is suitable for monitoring the leakage of non-conductive liquids and does not need to perform chemical reactions according to the chemical components of different oils.

[0028] The sensor of the present invention can be placed at locations where non-conductive oil is prone to leak in industrial equipment or components (such as pipeline connections, valve seals, pump shaft seals, cylinder seals, etc.) to monitor whether there is an oil leakage problem. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 This is a schematic diagram of the structure of a monitoring system in an embodiment of the present application (a porous oil-absorbing material layer is provided below the sensor);

[0031] Figure 2 for Figure 1 Schematic diagram of the cross-sectional structure of the monitoring system (the porous oil-absorbing material layer is provided with grooves);

[0032] Figure 3 for Figure 2 A schematic diagram of the structure of a porous oil-absorbing material layer with grooves used in the invention;

[0033] Figure 4 for Figure 1 Schematic diagram of the state of the sensor in the monitoring system after it contacts the non-conductive oil;

[0034] Figure 5 This is a schematic diagram of the structure of the monitoring system in the embodiment of the present application (with two upper and lower porous oil-absorbing material layers)

[0035] Figure 6 for Figure 5 Schematic diagram of the state of the sensor in the monitoring system after it contacts the non-conductive oil;

[0036] Figure 7 It is a structural schematic diagram of a detection system in an embodiment of the present application (ring wire type);

[0037] Figure 8 It is a structural schematic diagram of a monitoring system in an embodiment of the present application (container type);

[0038] Fig. 9 This is a schematic diagram of the structure of a sensor with a housing in Example 2 of the present application. DETAILED DESCRIPTION

[0039] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0040] Example 1

[0041] like Figure 1 , Figure 2 , Figure 5 , Figure 7 As shown, the present invention provides a sensor for monitoring non-conductive oil leakage, comprising a conductor 2 formed of conductive powder, which is arranged in a judgment circuit and is used by the judgment circuit (1) to judge whether it is powered on or whether its resistance increases when powered on;

[0042] When not in contact with non-conductive oil, the conductor 2 formed by the conductive powder is in a conductive state with no change in resistance;

[0043] When in contact with non-conductive oil, due to the capillary phenomenon, the conductor 2 formed of the conductive powder is in a conductive state with increased resistance or in a non-conductive state.

[0044] The sensor of the present invention is based on the capillary phenomenon of liquid, that is, due to the combined effects of the surface tension, cohesive force and adhesive force of the liquid, the liquid can rise or diffuse in a capillary tube without external power.

[0045] When there is no contact with non-conductive oil, the conductive powder particles in the conductor 2 formed by the conductive powder are in close contact, so that the conductor 2 is in a conductive state; at this time, it is judged that the current of the circuit is in a path state, which is a normal state, and the resistance does not change.

[0046] Since there are gaps between the conductive powder particles of conductor 2, when they come into contact with non-conductive oil, a capillary phenomenon will occur, and the non-conductive oil will diffuse between the conductive powder particles, thereby increasing the resistance of conductor 2 (the resistance is minimum when the conductive powder does not come into contact with the non-conductive oil. Therefore, if the leakage is small and not enough to disconnect the circuit, the leakage can be determined by measuring the change in resistance.); as the leakage of oil increases, an insulating space will be formed between the conductive powder particles (that is, the conductive powder is dispersed in the oil), causing the conductive powder to be in a loose state and the whole to be non-conductive, thereby causing the circuit of the circuit system to be disconnected.

[0047] Using the above principle, a conductor 2 formed of conductive powder is placed between two wires 1-1 of the judgment circuit 1, and the current of the judgment circuit forms a path under the action of the conductor 2. The sensor is placed at the non-conductive oil leakage prone position of industrial equipment or components (such as the connection of the pipeline, the sealing of the valve, the shaft seal of the pump, the sealing of the oil cylinder, etc.) to monitor whether there is an oil leakage problem.

[0048] The above-mentioned conductive powder includes metal powder and / or carbon powder, and the metal powder includes single metal powder (such as copper powder, iron powder, aluminum powder, nickel powder, silver powder, bismuth powder, tungsten powder, cobalt powder, chromium powder, niobium powder, molybdenum powder, tantalum powder, tin powder, etc.), two or more single metal powders, metal oxide powder and / or alloy powder.

[0049] The carbon-based powder includes graphite, carbon black, carbon fiber, graphene, etc.

[0050] The judgment circuit in the present application is a circuit for judging whether a circuit is on or off and judging the change of resistance, which is a conventional technical means of those skilled in the art and is widely used in various judgment circuits such as multimeters, etc. No further description is given here.

[0051] The particle size of the metal powder has a great influence on monitoring. When the particle size of the metal powder is too large, even if the powder with conductive function contacts a large amount of oil, the oil cannot carry and dilute it (that is, the conductive powder cannot be dispersed in the oil). Therefore, as a preferred embodiment, the particle size of the metal powder is less than 300 μm.

[0052] The conductor 2 formed by the conductive powder can be formed by sprinkling the conductive powder between the two wires of the judgment circuit to energize the judgment circuit, or by lightly pressing the top of the powder with a flat plate after sprinkling; the thickness of the conductor 2 should be moderate, specifically, the thickness of the conductor 2 formed by the conductive powder is 0.2mm-2mm without pressing; after lightly pressing with a flat plate, the thickness of the conductor 2 formed by the conductive powder becomes 0.1mm-1.5mm. If the thickness is too thick, the sensitivity of monitoring will be reduced, and if it is too thin, it will affect the conductive effect. There is no specific restriction on the shape of the conductor 2, which can be a long strip, a round cake, or other shapes flexibly designed according to the shape of the monitored part, and can also be flexibly designed according to the shape of the monitored part.

[0053] Example 2

[0054] When the sensor in Example 1 relies solely on the capillary phenomenon of the conductor 2 formed by the conductive powder to monitor oil leakage, the conductive powder needs to be immersed in a relatively large amount of oil and for a relatively long time to achieve the effect of increasing resistance and disconnecting the circuit. Therefore, the sensitivity of the sensor is not high and the overall stability of the sensor is poor.

[0055] In order to shorten the reaction speed, reduce the amount of oil required to identify the leak, and improve the effect of trace monitoring and the sensitivity of monitoring, based on the technical solution in Example 1, as Figure 2 and Figure 5 As shown, a porous oil-absorbing material layer 3 is provided on the upper and / or lower part of the conductor 2 formed of conductive powder. That is, the conductive powder is constrained by the porous oil-absorbing material layer 3 on the upper and / or lower part of the conductor 2 formed of conductive powder, which also improves the stability of the sensor against vibration.

[0056] The conductor 2 formed of conductive powder and the porous oil-absorbing material layer 3 are arranged together, which can shorten the time for identifying a leak, reduce the amount of oil required to identify a leak, and improve the effect of trace monitoring. Figure 4 and Figure 6 As shown, when the leaked non-conductive oil contacts the porous oil-absorbing material layer 3, it will quickly reach the conductor 2 formed by the conductive powder through the porous oil-absorbing material 3 and contact the conductive powder. Then, the leaked oil mixed with the conductive powder will quickly diffuse to the porous material (porous oil-absorbing material 3) through the capillary phenomenon, accelerating the transformation of the conductive powder from conductive to non-conductive. With the porous material, the judgment of trace leakage can be realized.

[0057] The oil absorbing material may be felt, cloth, sponge, or plastic, metal, ceramic or synthetic material. As long as the material has a porous structure, it can diffuse the oil and conductive powder through capillary action.

[0058] Oil-absorbing materials can be made into various shapes according to actual application scenarios.

[0059] As a preferred embodiment, Figure 5 As shown, a porous oil-absorbing material layer 3 is provided on the upper and lower parts of the conductor 2 formed by conductive powder. When in use, the conductive powder is placed on the porous oil-absorbing material layer 3 at the lower part, and then another porous oil-absorbing material layer 3 is placed on the upper part of the conductor 2 formed by the conductive powder. In addition to improving the sensitivity of the sensor, this arrangement can also form a certain constraint and fixation on the conductor 2 formed by the conductive powder by the upper and lower porous oil-absorbing material layers 3.

[0060] In order to further improve the stability of the sensor in this embodiment, Fig. 9 As shown, a housing 5 that allows oil to pass through is also provided outside the sensor.

[0061] The way to allow the oil to pass through can be to open one or more holes 5-1 on the shell 5, and the oil can enter the porous oil-absorbing material layer 3 through the holes 5-1. The use of the shell 5 can improve the stability of the sensor and prevent the position change between the porous oil-absorbing material layer 3 and the conductor 2 due to factors such as vibration and movement. Specifically, the sum of the thickness of the two porous oil-absorbing material layers 3 in the uncompressed state plus the thickness of the conductor 2 in the uncompressed state must be greater than the height of the cavity inside the shell 5. The purpose of such a setting is to achieve compression and fixation of the porous oil-absorbing material layer 3 and the conductive powder by controlling the shell 5. In the uncompressed state, the sum of the thickness of the porous oil-absorbing material layer 3 and the conductor 2 cannot be much greater than the height of the cavity inside the shell 5. If it is too much greater, the conductive powder will be pressed too tightly, which is not conducive to the diffusion of the oil. The uncompressed state refers to the state when the porous oil-absorbing material layer 3 and the conductor 2 are not installed in the shell 5, and the compressed state refers to the state when the porous oil-absorbing material layer 3 and the conductor 2 are assembled in the shell 5.

[0062] As a preferred embodiment, the sum of the thickness of the porous oil-absorbing material layer 3 and the conductor 2 in an uncompressed state is 0.5-10 mm greater than the height of the cavity inside the housing 5 .

[0063] In the uncompressed state, the conductor 2 formed by the conductive powder has a thickness of 0.2 mm to 2 mm. In the compressed state, the conductor 2 formed by the conductive powder has a thickness of 0.1 mm to 1.5 mm.

[0064] When a porous oil-absorbing material layer 3 is provided on the upper part and / or the lower part of the conductor 2 formed of the conductive powder, in order to further enhance the stability of the conductor 2 formed of the conductive powder, as Figure 2 and 3As shown, a groove 3-1 for constraining the conductor 2 formed of conductive powder is provided on the porous oil-absorbing material layer 3. In this way, the conductor 2 formed of conductive powder can be constrained in the groove 3-1, thereby enhancing its stability.

[0065] Example 3

[0066] Based on the sensor for monitoring non-conductive oil leakage in embodiments 1 and 2, as Figure 1 , Figure 2 , Figure 5 , Figure 7 and Fig. 9 As shown, the present application provides a monitoring system for monitoring non-conductive oil leakage, the monitoring system comprising a judgment circuit 1 and a sensor for monitoring non-conductive oil leakage arranged between two wires 1-1 of the judgment circuit 1, the sensor comprising a conductor 2 formed of conductive powder, which is arranged in the judgment circuit and judged by the judgment circuit 1 whether it is powered on or whether the resistance increases when powered on;

[0067] When not in contact with non-conductive oil, the conductor 2 formed by the conductive powder is in a conductive state with no change in resistance;

[0068] When in contact with non-conductive oil, due to the capillary phenomenon, the conductor 2 formed of the conductive powder is in a conductive state with increased resistance or in a non-conductive state.

[0069] Based on the above technical solution, the monitoring system is also provided with an alarm system 4 for sending an alarm signal to the outside when the judgment circuit 1 detects an increase in resistance or when the circuit is disconnected. The alarm system 4 can be an audible or visual alarm signal, or can send a warning signal to a user's mobile phone, computer or other terminal set in advance.

[0070] Figure 8 2 shows the structure of a monitoring system, in which a conductor 2 formed of conductive powder is arranged in a container.

[0071] Example 4

[0072] Based on the sensors in Examples 1 and 2 and the monitoring system in Example 3, the present application provides a method for monitoring leakage of non-conductive oil. Specifically, the sensors in the monitoring system are placed at locations where non-conductive oil of the industrial equipment or components to be monitored is prone to leakage, such as pipe connections, valve seals, pump shaft seals, oil cylinder seals, etc.

[0073] (1) When not in contact with non-conductive oil, the conductor 2 formed by the conductive powder is in a conductive state with no change in resistance, and it is judged that the circuit 1 is connected, which is a normal state;

[0074] (2) When there is oil leakage, if the amount of oil leakage is small and not enough to disconnect the conductor 2 formed by the conductive powder, the conductor 2 formed by the conductive powder is in a state where it can conduct electricity and the resistance increases. At this time, the resistance of the judgment circuit 1 increases; as the amount of oil leakage increases, the conductor 2 formed by the conductive powder is in a non-conductive state, and the circuit of the judgment circuit (1) is disconnected.

[0075] Furthermore, when the resistance of the judgment circuit 1 increases or the circuit is disconnected, the monitoring system will send an alarm signal to the outside.

[0076] Each embodiment in this specification is described in a related manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the scope of protection of the present invention.

Claims

1. A sensor for monitoring non-conductive oil leakage, characterized in that: It comprises a conductor (2) formed of conductive powder and used for being arranged in a judgment circuit and for the judgment circuit (1) to judge whether it is powered on or whether the resistance increases when powered on; When not in contact with non-conductive oil, the conductor (2) formed by the conductive powder is in a conductive state with no change in resistance; When contacting with non-conductive oil, the oil diffuses in the gaps of the conductive powder due to the capillary phenomenon, causing the conductor (2) formed by the conductive powder to be in a conductive state with increased resistance or in a non-conductive state.

2. The sensor for monitoring non-conductive oil leakage according to claim 1, characterized in that: The conductive powder includes metal powder and / or carbon powder.

3. The sensor for monitoring non-conductive oil leakage according to claim 2, characterized in that: The metal powder is a single metal powder, two or more single metal powders, metal oxide powder and / or alloy powder; the carbon-based powder is at least one of graphite, carbon black, carbon fiber and graphene.

4. The sensor for monitoring non-conductive oil leakage according to claim 1, characterized in that: The particle size of the metal powder is less than 300 μm.

5. The sensor for monitoring non-conductive oil leakage according to claim 1, characterized in that: The upper part and / or the lower part of the conductor (2) formed of conductive powder is provided with a porous oil-absorbing material layer (3).

6. The sensor for monitoring non-conductive oil leakage according to claim 5, characterized in that: The material of the porous oil-absorbing material layer (3) is felt, cloth, sponge, porous plastic, porous metal or porous ceramic.

7. The sensor for monitoring non-conductive oil leakage according to claim 5, characterized in that: The upper and lower parts of the conductor (2) formed of conductive powder are both provided with porous oil-absorbing material layers (3), and the outside of the sensor is also provided with a shell (5) that allows oil to pass through.

8. The sensor for monitoring non-conductive oil leakage according to claim 7, characterized in that: The sum of the thickness of the upper and lower porous oil-absorbing material layers (3) in an uncompressed state plus the thickness of the conductor (2) in an uncompressed state is greater than the height of the cavity inside the housing (5).

9. The sensor for monitoring non-conductive oil leakage according to claim 5, characterized in that: The porous oil-absorbing material layer (3) is provided with grooves (3-1) for constraining the conductor (2) formed by conductive powder.

10. The sensor for monitoring non-conductive oil leakage according to claim 8, characterized in that: In an uncompressed state, the thickness of the conductor (2) formed by the conductive powder is 0.2 mm to 2 mm, and in a compressed state, the thickness of the conductor (2) formed by the conductive powder is 0.1 mm to 1.5 mm.

11. A monitoring system for monitoring non-conductive oil leakage, characterized in that: It comprises a judgment circuit (1) and a sensor for monitoring non-conductive oil leakage arranged between two wires (1-1) of the judgment circuit (1), wherein the sensor is the sensor according to any one of claims 1 to 10; When not in contact with non-conductive oil, the conductor (2) of the sensor formed of conductive powder is in a conductive state with no change in resistance; When contacting with non-conductive oil, the oil diffuses in the gaps of the conductive powder due to the capillary phenomenon, causing the conductor (2) of the sensor formed by the conductive powder to be in a conductive state with increased resistance or in a non-conductive state.

12. A method for monitoring non-conductive oil leakage, characterized in that: Using the sensor according to any one of claims 1 to 10, or using the monitoring system according to claim 11; When using: (1) When not in contact with non-conductive oil, the conductor (2) formed by the conductive powder is in a conductive state with no change in resistance, and it is judged that the circuit (1) is connected, which is a normal state; (2) When there is oil leakage, if the amount of oil leakage is small and insufficient to disconnect the conductor (2) formed by the conductive powder, the conductor (2) formed by the conductive powder is in a state where it can conduct electricity and the resistance increases. At this time, the resistance of the judgment circuit (1) increases; as the amount of oil leakage increases, the conductor (2) formed by the conductive powder is in a non-conductive state, and the circuit of the judgment circuit (1) is disconnected.

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