Leak detector for underground pipe network

Abstract

The utility model discloses an underground pipe network leak detector belongs to leak detector technical field, this underground pipe network leak detector includes: detection head, probe rod and controller, detection head has interdigital capacitor, and one end of probe rod is connected with detection head, is equipped with a plurality of interval arrangement detection unit on the probe rod, and each detection unit is used to detect the humidity and temperature of the corresponding position soil, and the controller is installed in the probe rod, and the controller is connected with interdigital capacitor and detection unit communication respectively, and the underground pipe network leak detector can realize accurate judgment to whether the underground pipe network leaks, and reduces the false alarm risk.

Description

Technical Field

[0001] This utility model relates to the field of leak detector technology, and more specifically, to an underground pipeline leak detector. Background Technology

[0002] Underground plastic pipe networks are widely used in municipal and industrial fields due to their advantages such as corrosion resistance, light weight and convenient construction. However, leakage problems in buried environments have long plagued operation and maintenance work.

[0003] Current mainstream leak detection technology usually uses soil moisture detection, but its measurement response is slow, it is easily affected by environmental factors such as rainfall and evaporation, its detection accuracy is poor, and it is prone to false alarms. Utility Model Content

[0004] This invention aims to at least partially solve one of the aforementioned technical problems in the prior art. To this end, this invention proposes an underground pipeline leak detector, which can accurately determine whether an underground pipeline is leaking and reduce the risk of false alarms.

[0005] According to some embodiments of this utility model, the underground pipeline leak detector includes: a detection head having an interdigitated capacitor; a probe rod having one end connected to the detection head, and a plurality of spaced detection units arranged on the probe rod, each detection unit being used to detect the moisture and temperature of the soil at its corresponding location; and a controller installed on the probe rod, the controller being communicatively connected to the interdigitated capacitor and the detection units respectively.

[0006] According to the underground pipeline leak detector of this utility model embodiment, one end of the probe rod is connected to the detection head, and multiple detection units are arranged at intervals on the probe rod. Each detection unit is used to detect the humidity and temperature of the soil at its corresponding location. The controller is connected to the interdigitated capacitor of the detection head and the detection unit for communication. The underground pipeline leak detector can accurately determine whether the underground pipeline is leaking and reduce the risk of false alarms.

[0007] According to some embodiments of the present invention, a plurality of the detection units are arranged in a spiral pattern at intervals along the outer surface of the probe.

[0008] According to some embodiments of the present invention, in the axial direction of the probe rod, a plurality of detection units are distributed at equal intervals, and in the circumferential direction of the probe rod, two adjacent detection units have the same phase difference.

[0009] According to some embodiments of the present invention, the distance between two adjacent detection units in the axial direction of the probe is 10mm to 50mm, and the phase difference between two adjacent detection units in the circumferential direction of the probe is 5° to 30°.

[0010] According to some embodiments of the present invention, the detection unit includes a temperature sensor and a humidity sensor encapsulated in a coplanar manner.

[0011] According to some embodiments of this utility model, the probe rod is constructed as a telescopic rod.

[0012] According to some embodiments of the present invention, the probe includes: a shape memory alloy skeleton, a carbon fiber layer, and a heater. The carbon fiber layer is adhered to the shape memory alloy skeleton, and the heater is used to heat the shape memory alloy skeleton to cause it to shrink.

[0013] According to some embodiments of this utility model, the probe rod is a hollow rod, and the interdigitated capacitor and the detection unit are communicatively connected to the controller through their respective signal lines, the signal lines being located in the hollow area inside the probe rod.

[0014] According to some embodiments of the present invention, the interdigitated capacitor includes: a ceramic substrate connected to one end of the probe; and a plurality of finger electrodes arranged at intervals along the length of the ceramic substrate, wherein one of two adjacent finger electrodes is a driving electrode and the other is a sensing electrode.

[0015] According to some embodiments of the present invention, in the length direction of the ceramic substrate, the width of the finger electrode is 0.1 mm to 0.5 mm, and the spacing between two adjacent finger electrodes is 0.5 mm to 5 mm.

[0016] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] Figure 1 This is a structural schematic diagram of an underground pipeline leak detector according to an embodiment of the present utility model.

[0018] Figure label: Detection head 1; interdigital capacitor 11; ceramic substrate 111; finger electrode 112; Probe 2, Detection Unit 21; Controller 3; 10. Underground pipe network leak detector. Detailed Implementation

[0019] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0020] In the description of this utility model, it should be understood that the terms "length", "width", "thickness", "upper", "lower", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0022] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0023] The underground pipeline leak detector 10 according to an embodiment of the present invention is described in detail below with reference to the accompanying drawings.

[0024] Reference Figure 1 As shown, the underground pipeline leak detector 10 includes: a detection head 1, a probe 2, and a controller 3. The detection head 1 has an interdigital capacitor 11. One end of the probe 2 is connected to the detection head 1. The probe 2 is provided with multiple spaced detection units 21. Each detection unit 21 is used to detect the moisture and temperature of the soil at its corresponding location. The controller 3 is installed on the probe 2 and is communicatively connected to the interdigital capacitor 11 and the detection unit 21.

[0025] Specifically, the underground pipe network leak detector 10 can detect whether there is a leak in the underground plastic pipe network. When in use, the detection head 1 of the underground pipe network leak detector 10 can be facing downwards and the probe 2 can be inserted into the soil. The interdigitated capacitor 11 of the detection head 1 can accurately detect the soil moisture. The multiple detection units 21 on the probe 2 can detect the changes in soil moisture and temperature at their corresponding locations. The interdigitated capacitor 11 and the detection units 21 are all connected to the controller 3. The controller 3 can receive the data detected by the interdigitated capacitor 11 and the detection units 21, thereby determining whether there is a leak in the underground pipe network.

[0026] Understandably, when there is a leak in the underground pipe network, the leaked water will spread outward from the leak point, causing the soil to form a "wet ball" area with abnormal humidity centered on the leak point, and the closer the area is to the leak point, the greater the soil humidity.

[0027] The interdigitated capacitor 11 of the detection head 1 can measure soil moisture based on the characteristic that the dielectric constant of soil changes with moisture content. When the interdigitated capacitor 11 is inserted into the soil, its electric field will pass through the surrounding soil medium. Since the dielectric constant of water is much higher than that of soil and air, the overall dielectric constant of soil will increase significantly with the increase of moisture. The controller 3 can indirectly reflect the dielectric constant of the soil by obtaining the capacitance value of the interdigitated capacitor 11. Then, the capacitance value is converted into the corresponding volumetric moisture content through the pre-established calibration relationship, so as to realize the rapid and accurate detection of soil moisture.

[0028] Meanwhile, at least a portion of each detection unit 21 is located outside the probe 2. The detection unit 21 can detect the temperature and humidity of the soil in contact with it. The controller 3 can obtain the temperature and humidity information of different locations of the soil based on the detection results of each detection unit 21. Thus, based on the temperature and humidity information, interference from information such as rain and surface seepage can be eliminated to avoid false alarms.

[0029] It is understandable that soil temperature will affect the accuracy of humidity detection. Therefore, the detection unit 21 can measure the soil temperature and humidity, and the controller 3 can compensate and correct the humidity value according to the temperature measurement value to improve the accuracy of humidity measurement by the detection unit 21.

[0030] When the interdigitated capacitor 11 detects an increase in soil moisture, the controller 3 can confirm that there is a risk of leakage in the underground pipe network. The controller 3 can detect the moisture in different areas of the soil based on multiple detection units 21. When the moisture in different areas of the soil decreases radially, it can be determined that there is a "wet ball" area with abnormal soil moisture, which meets the characteristics of a leak point, and the controller 3 can issue a leak alarm. When the moisture in different areas of the soil does not decrease radially (for example, surface seepage caused by rain or irrigation, where the soil is a cone-shaped wet area with moisture decreasing from top to bottom), it can be determined that it does not meet the characteristics of a leak point, and the controller 3 may not issue a leak alarm.

[0031] The water leakage alarm can be a preset signal sent by the controller 3 to an external receiver, or it can be a signal to control the buzzer and lights to provide an alarm.

[0032] According to the underground pipeline leak detector 10 of this utility model embodiment, one end of the probe 2 is connected to the detection head 1. The probe 2 is provided with multiple detection units 21 arranged at intervals. Each detection unit 21 is used to detect the humidity and temperature of the soil at its corresponding location. The controller 3 is communicatively connected to the interdigitated capacitor 11 of the detection head 1 and the detection unit 21 respectively. The underground pipeline leak detector 10 can accurately determine whether the underground pipeline is leaking and reduce the risk of false alarms.

[0033] In some embodiments of this utility model, the detection head 1 further includes a capacitance detection circuit. The interdigitated capacitor 11 is connected to the controller through the capacitance detection circuit. The detection circuit can be based on the AD7746 chip to build a differential capacitance detection module with a resolution of 0.01fF and a soil volume moisture content sensitivity of 0.1%.

[0034] In some embodiments of this utility model, reference is made to Figure 1 As shown, multiple detection units 21 are arranged in a spiral pattern along the outer surface of the probe 2.

[0035] Specifically, multiple detection units 21 can be arranged at intervals along a spiral line on the outer surface of the probe 2. This spiral line can be a cylindrical spiral line. Thus, by using multiple detection units 21 with different orientations and positions, accurate measurement of the spatial distribution of soil moisture can be achieved. In other words, by using a spiral array of multiple detection units 21, soil moisture can be detected at different depths and orientations. At least one detection unit 21 can be roughly facing the leak point. When a detection unit 21 senses the moisture change preferentially due to its orientation, its adjacent detection units 21 with different orientations will sense weaker or different moisture, thereby providing directional information about the leak point.

[0036] The controller 3 can capture different sides of the "wet ball" area in the soil formed by the leak in the local pipeline network based on the multiple detection units 21 of the spiral array, and reconstruct the shape, size and center position of this abnormal moisture field in reverse, thereby locating the leak.

[0037] In some embodiments of this utility model, reference is made to Figure 1 As shown, multiple detection units 21 are evenly distributed in the axial direction of the probe rod 2, and adjacent two detection units 21 have the same phase difference in the circumferential direction of the probe rod 2. This achieves a uniform distribution of multiple detection units 21 in multiple directions and at multiple depths, which is beneficial for uniformly detecting soil moisture at different depths and directions of the soil where the probe rod 2 is located, reducing detection blind spots, and improving the detection coverage of soil moisture.

[0038] In some embodiments of this utility model, the distance between two adjacent detection units 21 in the axial direction of the probe 2 is 10mm to 50mm. That is, when the probe 2 is vertically inserted into the soil, the axial direction of the probe 2 is up and down. In the up and down direction, the distance between two adjacent detection units 21 is 10mm to 50mm, for example, 10mm, 20mm, 30mm, 40mm or 50mm, so as to ensure the detection density of multiple detection units 21 on soil at different depths, so as to facilitate the location of the leak.

[0039] The phase difference between two adjacent detection units 21 in the circumferential direction of the probe rod 2 is 5° to 30°. That is to say, in the circumferential direction of the probe rod 2, two adjacent detection units 21 form an angle of 5° to 30° with the axis of the probe rod 2 as the center. The phase difference between two adjacent detection units 21 can be 5°, 15° or 30°, thereby ensuring the detection density of multiple detection units 21 in different directions of the probe rod 2, so as to locate the leak point.

[0040] In one specific embodiment of this utility model, the number of detection units 21 is 24, the distance between two adjacent detection units 21 in the axial direction of the probe rod 2 is 30mm, and the phase difference between two adjacent detection units 21 in the circumferential direction of the probe rod 2 is 15°.

[0041] In some embodiments of this utility model, the detection unit 21 includes a temperature sensor and a humidity sensor coplanarly packaged. That is, the temperature sensor and the humidity sensor are fabricated on the same plane of the same substrate through microfabrication processes (such as photolithography and film coating). The coplanar packaging of the temperature sensor and the humidity sensor can improve the integration of the detection unit 21, so as to densely arrange a large number of detection units 21 on the probe 2. Furthermore, the temperature sensor and the humidity sensor measure the same point of the soil. The coplanar packaging ensures that the temperature and humidity are measured at the same soil location, eliminating the measurement error caused by the spatial separation of the sensors, thereby improving the accuracy of temperature correction for humidity.

[0042] In some embodiments of this utility model, the temperature sensor is a PT1000 thin-film resistance temperature sensor with a temperature sampling rate of 10Hz and an accuracy of ±0.1℃, and the humidity sensor is a capacitive humidity sensor.

[0043] In some embodiments of this utility model, the probe 2 is constructed as a telescopic rod, which can measure the moisture content at different soil depths by extending or retracting the length of the probe 2, thereby expanding the applicability of the underground pipeline leak detector 10.

[0044] Optionally, the probe rod 2 is constructed as a hydraulic telescopic rod, or the probe rod 2 includes a lower probe rod and an upper probe rod connected by threads, and the length of the probe rod 2 can be extended or retracted by adjusting the threaded area of ​​the lower probe rod and the upper probe rod.

[0045] In some embodiments of this utility model, the probe 2 includes: a shape memory alloy skeleton, a carbon fiber layer, and a heater. The carbon fiber layer is adhered to the shape memory alloy skeleton, and the heater is used to heat the shape memory alloy skeleton to cause it to shrink.

[0046] Specifically, the material of the shape memory alloy skeleton can be a copper-based shape memory alloy, such as Cu-Al-Zn-Ni shape memory alloy or Cu-Zn-Al shape memory alloy. The shape memory alloy skeleton can be a mesh tube structure that shrinks radially after heating. The carbon fiber layer is adhered to the shape memory alloy skeleton to improve the structural strength of the probe 2, so that the probe 2 can withstand the pressure of the soil. The heater can be a PTC electric heater. When it is necessary to pull the probe 2 out of the soil, the heater can heat the shape memory alloy skeleton to make it shrink the carbon fiber layer, thereby reducing the radial dimension of the probe 2 and making the probe 2 at least partially separate from the soil in the radial direction, so as to facilitate the pulling of the probe 2 out of the soil and reduce the frictional resistance of the soil to the probe 2.

[0047] In some embodiments of this utility model, the probe rod 2 is a hollow rod, and the interdigitated capacitor 11 and the detection unit 21 are connected to the controller 3 through their respective signal lines. The physical connection of the signal lines can ensure the stability and reliability of signal transmission. At the same time, the signal lines are located in the hollow area inside the probe rod 2, and the probe rod 2 can protect the signal lines inside, reducing the risk of short circuits and corrosion of the signal lines.

[0048] In some embodiments of this utility model, the outer diameter of the probe rod 2 is 25mm, its extension stroke is 2.5m, and its positioning accuracy is ±1cm.

[0049] In some embodiments of this utility model, reference is made to Figure 1 As shown, the interdigital capacitor 11 includes a ceramic substrate 111 and a plurality of finger electrodes 112. The ceramic substrate 111 is connected to one end of the probe 2. The plurality of finger electrodes 112 are arranged at intervals along the length direction of the ceramic substrate 111. Among two adjacent finger electrodes 112, one is a driving electrode and the other is a sensing electrode.

[0050] Specifically, the ceramic substrate 111 can be an aluminum nitride ceramic substrate. The ceramic substrate 111 has a rectangular thin plate structure with a thickness of 0.5 mm. The ceramic substrate 111 is easy to pattern on its surface to form two sets of independent, spaced, and alternately arranged finger electrodes 112. The finger electrodes 112 can be elongated conductors with pure gold plating on their outer surface to reduce the low-loss transmission of electrical signals. They have strong anti-oxidation and anti-corrosion capabilities, ensuring the reliability and service life of the finger electrodes 112. Two sets of finger electrodes 112 serve as the driving electrode and sensing electrode of the interdigital capacitor 11, respectively. The driving electrode and sensing electrode are arranged in parallel and alternately to form an interdigital planar pattern. When an AC signal is applied to the driving electrode, electric field lines will be emitted from the driving electrode, pass through the soil, and terminate at the adjacent sensing electrode, thus forming a complete electric field loop. The capacitance value of this loop will change with the change of the dielectric constant of the medium. Since the dielectric constant of water is much greater than that of dry soil and air, a small change in soil moisture will cause a significant change in capacitance value, thereby realizing the measurement of soil moisture.

[0051] In some embodiments of this utility model, reference is made to Figure 1 As shown, along the length of the ceramic substrate 111, the width of the finger electrode 112 is 0.1 mm to 0.5 mm, and the spacing between two adjacent finger electrodes 112 is 0.5 mm to 5 mm. That is to say, in... Figure 1 In the vertical direction, the width of the finger electrode 112 is 0.1 mm to 0.5 mm, for example, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, or 0.5 mm. The spacing between two adjacent finger electrodes 112 is 0.5 mm to 5 mm, for example, 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, or 5 mm. The width and spacing of the finger electrode 112 can jointly affect the distribution density of the electric field and the detection sensitivity. When the width of the finger electrode 112 is 0.1 mm to 0.5 mm and the spacing is 0.5 mm to 5 mm, more electrode pairs can be arranged in a unit area of ​​ceramic substrate 111, thereby enhancing the signal strength and improving the detection accuracy of soil moisture.

[0052] In some embodiments of this invention, the spacing between the plurality of finger electrodes 112 along the length of the ceramic substrate 111 gradually varies according to a logarithmic function; that is, in Figure 1 In the vertical direction, the spacing of the finger electrodes 112 can be arranged in a logarithmic function. By setting electrode pairs with different spacings on the ceramic substrate 111, soil moisture information from near field to far field and from micro to macro can be acquired simultaneously.

[0053] According to the underground pipe network leak detector 10 of this utility model embodiment, the controller 3 can utilize interdigitated capacitors 11 and multiple sensors to realize three-dimensional humidity gradient array and multi-physics field coupling for diagnosing side leaks. It can achieve a resolution of 0.1% volumetric water content and continuous detection at depths of 0.5m-3m. Environmental interference is eliminated through temperature-humidity joint calibration and dual-frequency conductivity compensation algorithms. The controller 3 can also construct dynamic baselines and spatiotemporal dual-dimensional leak judgment rules based on LSTM neural networks to improve the accuracy of leak point identification. In addition, the underground pipe network leak detector 10 can also combine biomimetic hydrophilic-hydrophobic coating power supply and magnetic resonance wireless relay to ensure long-term stable operation of the system. Experimental verification shows that this leak detector can identify minute leaks of 0.1L / h, with a false alarm rate of <3% in rainfall environments. The mass production cost is only 1 / 5 of that of traditional acoustic detectors. It is suitable for various soil types such as clay and sand, providing an efficient solution for leak detection in underground plastic pipe networks.

[0054] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0055] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A leak detector for underground pipe networks, characterized in that, include: A detection head (1) having interdigitated capacitors (11); The probe (2) is connected at one end to the detection head (1). The probe (2) is provided with multiple detection units (21) arranged at intervals. Each detection unit (21) is used to detect the humidity and temperature of the soil at its corresponding position. The controller (3) is installed on the probe (2) and is communicatively connected to the interdigitated capacitor (11) and the detection unit (21).

2. The underground pipeline leak detector according to claim 1, characterized in that, Multiple detection units (21) are arranged in a spiral pattern along the outer surface of the probe (2).

3. The underground pipeline leak detector according to claim 2, characterized in that, In the axial direction of the probe (2), a plurality of detection units (21) are distributed at equal intervals, and in the circumferential direction of the probe (2), two adjacent detection units (21) have the same phase difference.

4. The underground pipeline leak detector according to claim 3, characterized in that, The distance between two adjacent detection units (21) in the axial direction of the probe (2) is 10 mm to 50 mm, and the phase difference between two adjacent detection units (21) in the circumferential direction of the probe (2) is 5° to 30°.

5. The underground pipeline leak detector according to any one of claims 1-4, characterized in that, The detection unit (21) includes a temperature sensor and a humidity sensor that are coplanarly packaged.

6. The underground pipeline leak detector according to claim 1, characterized in that, The probe (2) is constructed as a telescopic rod.

7. The underground pipeline leak detector according to claim 1, characterized in that, The probe (2) includes: a shape memory alloy skeleton, a carbon fiber layer and a heater, wherein the carbon fiber layer is adhered to the shape memory alloy skeleton and the heater is used to heat the shape memory alloy skeleton to cause it to shrink.

8. The underground pipeline leak detector according to claim 1, characterized in that, The probe (2) is a hollow rod. The interdigitated capacitor (11) and the detection unit (21) are connected to the controller (3) through their respective signal lines. The signal lines are located in the hollow area inside the probe (2).

9. The underground pipeline leak detector according to claim 1, characterized in that, The interdigitated capacitor (11) includes: A ceramic substrate (111) is connected to one end of the probe (2); Multiple finger electrodes (112) are arranged at intervals along the length direction of the ceramic substrate (111). In two adjacent finger electrodes (112), one is a driving electrode and the other is a sensing electrode.

10. The underground pipeline leak detector according to claim 9, characterized in that, Along the length of the ceramic substrate (111), the width of the finger electrode (112) is 0.1 mm to 0.5 mm, and the spacing between two adjacent finger electrodes (112) is 0.5 mm to 5 mm.

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