A triboelectric sensing device for pipeline leak detection and its preparation method

Abstract

The present invention provides a triboelectric sensing device for pipeline leak detection and a preparation method thereof. The device includes: a triboelectric power generation device disposed on the inner wall of the pipeline, which is a laminated structure composed of a base layer, an electrode layer, and a friction layer from outside to inside in sequence. The friction layer includes a positive friction layer and a negative friction layer; a receiving device integrated in the base layer of the triboelectric power generation device, which is used to receive the voltage signal generated by the triboelectric power generation device, rectify it through a series voltage division and then through a bridge rectifier circuit and perform capacitor filtering to generate a DC signal, and provide an electrical emission alarm signal to a Bluetooth transmitter. By arranging each layer of the laminated structure of the triboelectric power generation device on a flexible wood layer, the present invention achieves the effect of freely stretching and bending, perfectly fits the inner wall of the pipeline, can effectively monitor and warn the pipeline breakage condition and the health state of the pipeline, does not require external power supply, can achieve the effect of self-power supply, and has the advantages of convenient disassembly, simple operation, fast detection speed, high detection accuracy, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline leak detection, and particularly to a triboelectric sensing device for pipeline leak detection and a preparation method thereof. Background Art

[0002] Pipeline transportation has become the fifth largest means of transportation in the world. With the rapid development of the economy and the continuous acceleration of the industrialization process, pipeline transportation is widely used in various fields. In sharp contrast, as the service life of pipelines increases, pipeline leakage incidents occur from time to time. For pipelines transporting energy such as oil and gas, the leakage of flammable substances not only wastes resources but also pollutes the environment, and may even threaten the lives and property safety of the surrounding people. Due to the flammable and explosive characteristics of the media in oil and gas transportation pipelines, once a leakage occurs, it is extremely easy to trigger accidents such as fires and explosions, causing casualties, property losses and environmental pollution. Therefore, it has great practical significance to study the relevant theories and technologies of oil and gas pipeline leakage detection and positioning.

[0003] The pipeline leak detection technology field is divided into internal detection methods and external detection methods. The internal detection method is to continuously monitor the state of parameters such as pressure, temperature, flow rate, sound velocity, viscosity, density or other pipeline parameters, and infer whether a leakage occurs based on the change amount of these parameters. The main internal detection methods include: negative pressure wave method, real-time transient model method, statistical analysis method, pressure / flow monitoring and analysis method, volume balance method, mass balance method, line balance method, etc. The external detection method is a physical detection method based on the change of the external environment parameters of the pipeline caused by the leakage medium through various sensing devices or cables, and mainly includes: optical fiber sensing technology, acoustic wave detection method, hydrocarbon vapor or liquid induction tube, infrared camera, etc. Among them, the leakage detection systems based on distributed optical fiber sensing technology, negative pressure wave technology and real-time transient model technology are commonly used and have relatively good effects in long-distance oil and gas pipelines.

[0004] At the present stage in the field of pipeline leak detection, most of the leak detection methods have limitations such as poor anti-interference ability and inability to achieve distributed real-time detection, which results in the existing methods not being able to fully meet the leak detection requirements. And the pipeline detection device based on triboelectric power generation has advantages such as small volume, self-powered, anti-electromagnetic interference, wavelength division multiplexing, high precision, corrosion resistance, etc., which can effectively solve the above problems. At present, the method of detecting pipeline gas leakage based on triboelectric power generation devices in China has not been widely popularized. Compared with the existing technology, detecting pipeline leakage based on triboelectric power generation has far-reaching significance and is one of the main means for detecting pipeline leakage problems and the health status of pipelines.

[0005] Therefore, there is an urgent need for a triboelectric sensing device for pipeline leak detection to solve the above problems. Summary of the Invention

[0006] According to the above-mentioned technical problems, a triboelectric sensing device for pipeline leak detection and its preparation method are provided. In the present invention, each layer of the laminated structure of the triboelectric generator is arranged on a flexible wood layer, which can freely stretch and bend, and can perfectly fit the inner wall of the pipeline, breaking through the limitations of the existing technology. It can effectively monitor and warn the pipeline damage condition and the health status of the pipeline. Without external power supply, it can achieve the effect of self-power supply, and has the advantages of convenient disassembly, simple operation, fast detection speed, high detection accuracy, etc.

[0007] The technical means adopted in the present invention are as follows:

[0008] A triboelectric sensing device for pipeline leak detection, comprising:

[0009] A triboelectric generator, arranged on the inner wall of the pipeline, is a laminated structure composed of a base layer, an electrode layer and a friction layer from outside to inside in sequence. The friction layer includes a positive friction layer and a negative friction layer;

[0010] A receiving device, integrated on the base layer of the triboelectric generator, is used to receive the voltage signal generated by the triboelectric generator. After series voltage division, it is rectified by a bridge rectifier circuit and filtered by a capacitor to generate a DC signal, which provides an electrical emission alarm signal for the Bluetooth transmitter.

[0011] Further, the receiving device is assembled by a single-chip microcomputer, diodes, capacitors and resistor elements. The friction layer of the triboelectric generator generates a peak signal through the lateral friction of the positive friction layer and the negative friction layer, and is received by the receiving device and subjected to curve analysis.

[0012] Further, the material of the friction layer uses wood material as the positive friction layer and polytetrafluoroethylene as the negative friction layer. The material of the electrode layer uses conductive metal, and the material of the base layer uses polyimide.

[0013] Further, the material of the electrode layer is selected from one of Cu, Ag, Au, Al or Pt.

[0014] Further, the thickness of the polyimide or polytetrafluoroethylene film is 30 nm to 180 nm.

[0015] The present invention also discloses a preparation method of a triboelectric sensing device for pipeline leak detection as described above. Connect the electrode layer to the external negative wire and the external positive wire respectively, and then stack and combine the base layer, the electrode layer and the friction layer from outside to inside in sequence. Among them, the thin film materials of the base layer, the electrode layer and the friction layer are all placed on a flexible wood layer, and the thickness ratio of the flexible wood layers adhered by the base layer, the electrode layer and the friction layer is 2:1:3; the base layer and the electrode layer adopt a face-to-face gluing process; the electrode layer and the friction layer adopt a non-gluing process.

[0016] Further, the flexible wood layer is obtained by cutting wood into pieces. First, soak the cut wood in a boiling solution containing KOH and Na2SO3 to dissolve lignin, and then use sodium chlorite solution to dissolve the remaining lignin. Add glacial acetic acid to adjust the pH, heat and stir until the wood is bleached white. Finally, wash with water and soak with ethanol, and then press and dry the wood for standby.

[0017] Further, the solution of KOH and Na2SO3 is mixed in the range of (90 - 60) g: 20 g, placed in a beaker, and 100 - 120 mL of water is added after mixing. At the same time, the cut wood is heated on a heating table at 100 °C for 11 - 18 hours.

[0018] Further, for the dissolution of the remaining lignin, add 3 - 5 g of sodium chlorite, stir well, add 80 ml - 120 ml of water, stir again, add glacial acetic acid to adjust the pH after stirring, and measure the pH value with a pH meter at the same time. Stop adding glacial acetic acid when the pH reaches below 4.5; place the beaker on the heating table again, adjust the heating table parameters to 100 °C, add a magnetic stirrer at the same time, and heat for 2 - 6 hours, depending on the thickness of the flexible wood layer. For a 1 mm thick flexible wood layer, heat for 2 hours, and the heating time increases sequentially for each additional 1 mm.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] 1. The friction layer of the present invention is the core part of the triboelectric sensing device. Most of the existing friction sensing devices use PET or PVC as the friction layer. Compared with the existing friction inductive devices, the friction layer of the present invention can be freely stretched and bent with wood materials and PEFT materials, and can be continuously used, breaking through the limitations of production and realizing the reuse of materials.

[0021] 2. The triboelectric sensing device provided by the present invention can output a high voltage to measure potential problems in pipelines and can accurately and quickly display the problems to the detector.

[0022] 3. Due to the flexibility of the structure of the triboelectric sensing device provided by the present invention, when the triboelectric power generation devices are evenly arranged, the measuring device will not be displaced or deformed due to a strong impact force. By setting the lateral sliding speed of the triboelectric power generation device, the charging and discharging time can be longer and the interference of external vibration can be eliminated. When receiving signals through the device, since the speed is slow, a more complex waveform can be output for analyzing internal problems and feeding back to the friction layer to control the speed, thereby increasing the duration of self-power supply.

[0023] 4. The present invention does not require an external power supply system, and through an integrated structure, not only the device structure is simplified, but also it is convenient to carry and easy to install and place.

[0024] In summary, the triboelectric sensing device provided by the present invention can be arrayed on the inner wall of the pipeline, is easy to disassemble, convenient to use, and easy to promote. Using flexible wood materials as the raw material of the triboelectric power generation and sensing device can achieve stable self-power supply and ensure the accuracy of detecting pipeline hidden dangers.

[0025] For the above reasons, the present invention can be widely promoted in the technical field of pipeline leak detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 It is an exploded view of the structure of the triboelectric sensing device of the present invention.

[0028] Figure 2 It is a schematic diagram of the structure of the triboelectric sensing device of the present invention.

[0029] Figure 3 It is a schematic diagram of the structure of the installation of the triboelectric sensing device of the present invention and the pipeline.

[0030] Figure 4 It is a circuit diagram of the receiving device of the present invention.

[0031] Figure 5 It is a schematic diagram of the high and low generated voltage of the triboelectric power generation device of the present invention from 0 to 25 s.

[0032] Figure 6 It is a schematic diagram of the high and low generated voltage of the triboelectric power generation device of the present invention from 0 to 50 s.

[0033] Figure 7Schematic diagram of the highest generated voltage reached by the triboelectric power generation device of the present invention within 0 - 25 s.

[0034] In the figure: 1. Triboelectric power generation device; 2. Wire; 3. Friction layer; 4. Positive friction layer; 5. Negative friction layer; 6. Electrode layer; 7. Substrate layer; 8. Triboelectric sensing device; 9. Pipeline. Specific embodiments

[0035] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0036] As Figure 1 and Figure 2 、 Figure 3 shown, the present invention discloses a triboelectric sensing device 8 for pipeline leak detection, including:

[0037] A triboelectric power generation device 1, disposed on the inner wall of the pipeline 9, and having a laminated structure composed of a substrate layer 7, an electrode layer 6, and a friction layer 3 from outside to inside in sequence, wherein the friction layer 3 includes a positive friction layer 4 and a negative friction layer 5;

[0038] A receiving device, integrated on the substrate layer 7 of the triboelectric power generation device 1, connected to an external device through a wire 2, and used to receive the voltage signal generated by the triboelectric power generation device 1. The circuit of the receiving device generates a DC signal after series resistance voltage division, rectification through a bridge rectifier circuit, and capacitor filtering through a capacitor. At the same time, an external light-emitting diode is used for signal lamp indication, and finally an electric emission alarm signal is provided by the Bluetooth transmitter in the single-chip microcomputer (as Figure 4 shown).

[0039] Specifically, the receiving device is assembled from a single-chip microcomputer, a diode, a capacitor, and a resistor element. The friction layer 3 of the triboelectric power generation device 1 generates a peak signal through the lateral friction of the positive friction layer 4 and the negative friction layer 5, and the signal is received by the receiving device and subjected to curve analysis.

[0040] The materials of the friction layer 3 are wood as the positive friction layer 4 and polytetrafluoroethylene as the negative friction layer 5. Most of the existing friction sensing devices use PET or PVC as the friction layer. Compared with the existing friction inductance devices, the friction layer made of wood and PEFT materials can be freely stretched and bent, and can be continuously used, breaking through the limitations of production and realizing the reuse of materials.

[0041] The material of the electrode layer 6 is a conductive metal selected from one of Cu, Ag, Au, Al or Pt; the material of the base layer 7 is polyimide.

[0042] Preferably, the polyimide or polytetrafluoroethylene film has a thickness of 30 nm to 180 nm.

[0043] The present invention also discloses a method for preparing a triboelectric sensor device 8 for pipeline leak detection as described above, wherein the electrode layer 6 is connected to an external negative electrode wire and an external positive electrode wire respectively using epoxy conductive adhesive, and then the base layer 7, the electrode layer 6 and the friction layer 3 are stacked in sequence from the outside to the inside, wherein the base layer 7 and the electrode layer 6 are bonded face to face; the electrode layer 6 and the friction layer 3 are bonded using a non-bonding process to provide movement space for self-power supply.

[0044] The thin film materials of the base layer 7, the electrode layer 6 and the friction layer 3 are all placed on the flexible wood layer, and the thickness ratio of the base layer, the electrode layer and the flexible wood layer to which the friction layer is adhered is 2:1:3.

[0045] Specifically, the flexible wood layer is made by cutting wood into blocks. In this embodiment, the wood is cut into 40*40 blocks. The cut wood is first immersed in a boiling solution containing KOH and Na2SO3, and then the remaining lignin is dissolved with sodium chlorite solution. After the lignin is dissolved, glacial acetic acid is added to adjust the pH, and the wood is heated and stirred until it is bleached white. Finally, it is washed with clean water and soaked in ethanol, and then the wood is flattened and dried for use.

[0046] Preferably, the KOH and Na2SO3 solutions are mixed in a ratio of 9:2 and placed in a beaker. After mixing, 90 ml of water is added. At the same time, the cut wood is heated at 100 degrees Celsius on a heating table for 11-18 hours. The setting time requirement is not strict and is determined according to the thickness of the wood. In order to prevent uneven stirring of the solution, a magnetic stirrer can be added to ensure that the solution can be fully stirred.

[0047] Preferably, 3.5 g of sodium chlorite is added, and after sufficient stirring, 90 ml of water is added, and the mixture is stirred again. After stirring, glacial acetic acid is added to adjust the pH value, and the pH value is measured by a pH meter. When the pH value reaches below 4.5, the addition of glacial acetic acid can be stopped; the beaker is placed on the heating table again, and the heating table parameters are adjusted to 100 degrees Celsius. A magnetic stirrer is added at the same time, and the mixture is heated for about 2 to 6 hours, depending on the thickness of the flexible wood layer. A 1 mm thick flexible wood layer is heated for 2 hours, and the heating time increases successively with each increase of 1 mm.

[0048] Finally, remove the heated beaker, pour the liquid in the beaker into the waste liquid tank, soak the wood samples in clear water for 6 hours for cleaning. After cleaning, pour them into the ethanol solution and soak for 12 hours. After soaking, put them into a dryer, set the drying temperature to 60 degrees, and flatten the wood samples after drying to obtain the required samples.

[0049] The core part of the triboelectric sensing device of the present invention is the friction layer 3, whose main function is to achieve the effect of charge separation. The friction layer 3 generates a potential difference based on the ability of wood and PTFE to gain and lose electrons, realizing electron transfer. Through the lateral sliding mode, the relative displacement between wood and PTFE generates a signal. Among them, positive charges are generated in the wood, which is called the positive friction layer 4; negative charges are generated in the PTFE, which is called the negative friction layer 5. Energy is captured between the positive friction layer 4 and the negative friction layer 5 by an external force (wind energy). The electrode layer 6 is the conductive layer of the triboelectric sensing device, which is made of a conductive metal material and functions to export the charges generated by the friction layer 3 to form a sensing signal. The electrode layer 6 is usually divided into two parts, the positive electrode and the negative electrode, which are respectively connected to the positive and negative charges of the friction layer 3, and function to export the charges generated by the friction layer 3 to form a sensing signal, which is received by the receiving device; the base layer 7 is located outside the electrode layer 6 and is the support layer of the pipeline leak detection triboelectric sensing device 8, and at the same time has an insulating effect.

[0050] Example 1

[0051] The detector evenly distributes multiple triboelectric sensing devices 8 provided by the present invention on the inner wall of the pipeline 9. When different parameters of contact area, force, frequency, and speed are applied, the triboelectric sensing device 8 will output corresponding sensing data according to different parameters.

[0052] Taking the wind speed of 2 m / s as an example, the triboelectric power generation device starts to operate, and the output voltage is 5V. As the wind speed increases, the output voltage gradually increases. Since the speed of the gas is not constant, the two polar friction plates will come into contact and separate again continuously. Based on the principle of triboelectrification and electrostatic induction coupling, an induced potential difference will be generated between the two electrodes. The induced potential difference drives electrons to flow between the two electrodes through the external circuit, thus forming a current, realizing the conversion of the kinetic energy of gas molecules into electrical energy, and then the health state of the pipeline can be measured. When encountering the position of pipeline leakage, obvious mutations and unevenness can be seen in the output voltage. From this information, the leakage position of the pipeline can be obtained.

[0053] Therefore, as Figures 5-7 is the voltage fluctuation value and the maximum voltage fluctuation value when there is a gas leakage in the pipeline. It is not difficult to find from Figure 7 that when there is a gas leakage in the pipeline, the measured maximum voltage can reach 110V. It can be seen from this that the present invention has achieved remarkable measurement effects.

[0054] The above embodiments are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A triboelectric sensing device for pipeline leak detection, characterized in that, Including: A triboelectric power generation device is provided on the inner wall of the pipeline. It has a laminated structure composed of a base layer, an electrode layer, and a friction layer from outside to inside. The friction layer includes a positive friction layer and a negative friction layer; A receiving device is integrated on the base layer of the triboelectric power generation device. It is used to receive the voltage signal generated by the triboelectric power generation device, rectify it through a series voltage division and then through a bridge rectifier circuit and perform capacitor filtering to generate a DC signal, and provide an electrical emission alarm signal to the Bluetooth transmitter; The material of the friction layer uses wood material as the positive friction layer and polytetrafluoroethylene as the negative friction layer. The material of the electrode layer uses conductive metal, and the material of the base layer uses polyimide; the thickness of the polyimide or polytetrafluoroethylene film is 30nm to 180nm; The thin film materials of the base layer, electrode layer, and friction layer are all placed on a flexible wood layer. The thickness ratio of the flexible wood layer adhered by the base layer, electrode layer, and friction layer is 2:1:

3.

2. The triboelectric sensing device for pipeline leak detection according to claim 1, wherein The receiving device is assembled by a single-chip microcomputer, diodes, capacitors, and resistor elements. The friction layer of the triboelectric power generation device generates a peak signal through the lateral friction of the positive friction layer and the negative friction layer, and is received by the receiving device and analyzed for the curve.

3. The triboelectric sensing device for pipeline leak detection according to claim 1, wherein The material of the electrode layer is selected from one of Cu, Ag, Au, Al, or Pt.

4. A method for preparing a triboelectric sensing device for pipeline leak detection according to any one of claims 1-3, characterized in that, Connect the electrode layer to the external negative wire and the external positive wire respectively, and then stack and combine the base layer, electrode layer, and friction layer from outside to inside. Among them, the thin film materials of the base layer, electrode layer, and friction layer are all placed on a flexible wood layer. The thickness ratio of the flexible wood layer adhered by the base layer, electrode layer, and friction layer is 2:1:3; the base layer and the electrode layer adopt a face-to-face gluing process; the electrode layer and the friction layer adopt a non-gluing process.

5. The preparation method according to claim 4, characterized in that, The flexible wood layer is obtained by cutting wood into pieces. First, soak the cut wood in a boiling solution containing KOH and Na2SO3 to dissolve the lignin, then use sodium chlorite solution to dissolve the remaining lignin, add glacial acetic acid to adjust the pH, heat and stir until the wood is bleached white, finally wash it with water and soak it in ethanol, and then press and dry the wood for standby.

6. The preparation method according to claim 5, characterized in that, The solution of KOH and Na2SO3 is mixed in the range of (90 - 60) g: 20 g, placed in a beaker, and 100 - 120 mL of water is added after mixing. At the same time, the cut wood is heated on a heating table at 100 degrees Celsius for 11 - 18 hours.

7. The preparation method according to claim 5, characterized in that, For the dissolution of the remaining lignin, add 3 - 5 g of sodium chlorite, stir well and then add 80 ml - 120 ml of water, stir again, add glacial acetic acid to adjust the pH after stirring, and measure the pH value with a pH meter at the same time. Stop adding glacial acetic acid when the pH value reaches below 4.5; place the beaker on the heating table again, and adjust the heating table parameters to 100 degrees Celsius. At the same time, add a magnetic stir bar and heat for 2 - 6 hours, depending on the thickness of the flexible wood layer. For a 1 mm thick flexible wood layer, heat for 2 hours, and the heating time increases sequentially for each additional 1 mm.

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