Sound wave device for liquid leakage detection

Abstract

The invention discloses a sound wave device for liquid leakage detection, which detects downwards from the upper part of a dam to the required preset detection height by means of a micro winch, and comprises a mobile vehicle body, the mobile vehicle body is connected to the output end of the micro winch through a flexible rope, and a micro cylinder is mounted on the mobile vehicle body. The output end of the micro air cylinder is downwards provided with a sound wave detection mechanism to drive the sound wave detection mechanism to move downwards to be tightly attached to the detection surface, the sound wave detection mechanism comprises a detector close to the detection surface, and the detector is sequentially connected with a sound wave signal amplifier and a sound wave analysis device through a communication cable. According to the method, a two-stage progressive strategy that a distributed optical fiber monitoring system is used for area initial positioning and then a sound wave device is used for accurate tracing is adopted, specifically, an embedded optical fiber recognizes a leakage area through temperature field abnormity, and an external sound wave detection mechanism achieves accurate positioning and water source property judgment by detecting seepage noise; and the sound wave device is improved and designed to realize accurate detection of the position of the leakage crack.

Description

Technical Field

[0001] This invention relates to the field of municipal water conservancy engineering technology, specifically to an acoustic device for detecting liquid leakage. Background Technology

[0002] Among various engineering structures, concrete structures account for the largest proportion. During the construction and operation of concrete dams, factors such as temperature, construction defects, external forces, changes in the dam foundation, environmental erosion, material aging, and extreme natural disasters can all cause concrete cracking. Concrete cracking can cause structural damage or localized failure, affecting its durability. Furthermore, under the action of huge external water loads, cracks will further increase structural damage. If not detected, assessed, and repaired or remedial measures are not taken in time, it can lead to catastrophic consequences such as dam collapse. Therefore, cracks are an important indicator of the safety status of concrete structures. Crack inspection, detection, and assessment of structures are crucial guarantees for the safety of large structures and an important aspect of engineering safety maintenance.

[0003] As attached Figure 1 As shown, the acoustic signals induced by seepage originate from water-rock interactions (changes in pore pressure, migration of fine particles, and propagation of microcracks), rather than the flow of the water itself. Whether it's reservoir water or water within the mountain, as long as it passes through the same crack network, the acoustic signals exhibit high similarity in rise time, ring count, and dominant frequency distribution. Furthermore, when acoustic waves propagate through the multi-layered media of concrete-bedrock-mountain, the waveform shaping effect causes the loss of source information when cracks penetrate different media, easily leading to positioning errors reaching the meter level, far exceeding the accuracy requirements for boundary identification between the dam and the mountain.

[0004] This case arose in order to resolve the aforementioned issues. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an acoustic device for detecting liquid leakage, which solves the problems mentioned in the background section.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an acoustic device for detecting liquid leakage, which descends from above a dam to a desired preset detection height using a miniature winch, includes a mobile vehicle. The mobile vehicle is connected to the output end of the miniature winch via a flexible rope. A miniature cylinder is mounted on the mobile vehicle, and an acoustic detection mechanism is mounted downwards at the output end of the miniature cylinder to drive the acoustic detection mechanism downwards to closely contact the detection surface. The acoustic detection mechanism includes a detector close to the detection surface. The detector is connected in sequence to an acoustic signal amplifier and an acoustic analysis device via a communication cable. The acoustic signal amplifier amplifies the weak acoustic signal and converts it into a digital signal. The acoustic analysis device determines the location and possible leakage channels through simulation analysis based on the intensity, wavelength, and frequency characteristics of the acoustic wave.

[0007] As a preferred embodiment, the detector is further provided with a soundproof cover, wherein the soundproof cover includes, from the outside to the inside, an arc-shaped soundproof layer, a damping buffer layer adhered in the middle, and a sound-absorbing layer adhered on the inner side.

[0008] As a preferred embodiment, the sound insulation layer can be made of 1-3mm thick steel plate, the middle damping buffer layer can be made of rubber, and the sound absorption layer can be made of sound-absorbing cotton.

[0009] As a preferred embodiment, the bottom of the damping buffer layer is further circumferentially expanded to form an annular pad, and the pad adopts a flexible sealing strip.

[0010] As a preferred embodiment, the outermost rigid part of the soundproof enclosure is connected to the output end of the miniature cylinder. The detector is placed inside the soundproof enclosure, secured, and close to the lower side of the enclosure. The acoustic signal amplifier and acoustic analysis device are mounted on the vehicle body outside the soundproof enclosure. The detector passes through the soundproof enclosure via a communication cable and is electrically connected to the acoustic signal amplifier and acoustic analysis device. The communication cable has a length allowance for flexible descent.

[0011] As a preferred embodiment, the soundproof cover is further provided with slots, and the slots are covered with sealing caps made of flexible material.

[0012] As a preferred embodiment, the thickness of the annular pad formed by circumferential expansion is further increased, and the communication cable passes through and exits from the side of the annular pad.

[0013] As a preferred option, a distributed optical fiber monitoring system is further used to initially determine the preset detection height. This distributed optical fiber monitoring system uses pre-embedded optical fibers, which are pre-embedded in a serpentine pattern along the dam axis at the upstream impermeable concrete layer of the dam body, with a straight section spacing of 0.5 m. A DTS temperature sensing optical cable is used to apply thermal pulses along the optical cable.

[0014] After adopting the above technical solution, the acoustic device for liquid leakage detection provided by the present invention has the following beneficial effects compared with the prior art: The device first uses an optical fiber area for initial positioning, and then uses an acoustic device for precise source tracing. The pre-embedded optical fiber uses temperature field anomalies to identify the leakage area, and the external acoustic detection mechanism achieves precise positioning and water source identification by detecting seepage turbulence noise. Furthermore, the acoustic device is improved to achieve precise detection at the location of leakage cracks. Attached Figure Description

[0015] Figure 1 This is a simplified schematic diagram of the seepage zone on the back slope of the earth dam of the present invention; Figure 2 This is a schematic diagram illustrating the application of the present invention; Figure 3 This is a cross-sectional schematic diagram of the assembly area of ​​the acoustic wave detection mechanism of the present invention; Figure 4 This is a schematic cross-sectional view of the soundproof enclosure structure of the present invention; Figure 5 This is a simplified schematic diagram illustrating the crack sensing principle of the present invention.

[0016] In the diagram, 1. Dam body; 2. Miniature winch; 3. Flexible rope; 4. Counterweight; 5. Mobile vehicle body; 6. Miniature cylinder; 7. Soundproof cover; 71. Sound insulation layer; 72. Damping buffer layer; 73. Sound absorption layer; 74. Sealing strip; 8. Detector; 9. Support rod; 10. Pulse heating device; 11. Distributed fiber optic modem; 12. Fiber optic cable; 13. Optical-optical composite cable. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0018] See appendix Figure 2-3 As shown, an acoustic device for detecting liquid leakage is used to descend from above the dam to the required detection height by means of a miniature winch 2. The miniature winch 2 is connected to a mobile vehicle 5 by a flexible rope 3. A miniature cylinder 6 is installed on the mobile vehicle 5. The output end of the miniature cylinder 6 is fitted with an acoustic detection mechanism that moves downward to fit closely to the surface of the dam body 1.

[0019] The acoustic wave detection mechanism includes a detector 8, which is placed close to the surface of the object being detected. For example, when detecting dam leakage, it would be placed directly against the dam surface. Its purpose is to receive sound waves while minimizing the reception of other sound waves propagating through the air. The detector 8 must have a certain surface area. The detector 8 is connected in sequence to an acoustic wave signal amplifier and an acoustic wave analysis device via a communication cable. The acoustic wave signal amplifier amplifies the weak acoustic wave signal and converts it into a digital signal. The acoustic wave analysis device, based on the characteristics of the sound wave, such as intensity, wavelength, and frequency, uses simulation analysis to determine the location and possible leakage channels.

[0020] To ensure that the acoustic detector 8 can detect more accurately on the outer surface of the dam body 1, a soundproof cover 7 is added to physically isolate the sound, especially to block the airborne sound transmission paths such as water flow impact and wind noise.

[0021] See appendix Figure 4 Specifically, the soundproof enclosure 7 comprises, from the outside to the inside, an arc-shaped sound insulation layer 71, a damping buffer layer 72 attached in the middle, and a sound-absorbing layer 73 (made of sound-absorbing cotton) attached to the inner side. The sound insulation layer 71 can be made of 1-3mm thick steel plate, providing both rigid support and sound insulation from the outside. The damping buffer layer 72 can be made of rubber to suppress / buffer the transmission of vibrations from the dam body 1 itself. Furthermore, the bottom of the damping buffer layer 72 expands outward to form an annular pad, which can be made of a flexible sealing strip 74 to prevent sound wave signal leakage within the internal soundproof enclosure 7.

[0022] The outermost rigid part of the soundproof cover 7 is connected to the output end of the miniature cylinder 6. The detector 8 is placed inside the soundproof cover 7, secured, and close to the lower side of the soundproof cover 7. The acoustic signal amplifier and acoustic analysis device are installed on the vehicle body outside the soundproof cover 7. The detector 8 is electrically connected to the acoustic signal amplifier and acoustic analysis device through the communication cable passing through the soundproof cover 7. The communication cable has a length margin to achieve flexible hanging and avoid rigid transmission.

[0023] This embodiment Figure 4 The communication cable passes through the soundproof enclosure 7 from above. Because sufficient space is needed to prevent it from detaching from the detector 8 due to external tension, and the presence of a rigid layer necessitates creating a large slot at the penetration point (too small a slot would easily cause rigid friction, resulting in poor sound insulation), a flexible sealing cover can be placed over this slot. Alternatively, the circumferentially expanded annular pad can be thickened (increasing from approximately 1cm to 2-3cm), with the communication cable passing through from the side.

[0024] A further design feature is that, since the flexible rope 3 extends downwards for a long time, the entire moving vehicle body 5 is prone to shifting during movement. Therefore, counterweights 4 (approximately 2-3 kg in weight) are set at intervals of the flexible rope 3 and are softly connected by the flexible rope. This makes it easier for the flexible rope 3 to lower the moving vehicle body 5 in a preset straight line and always maintain a relatively taut state.

[0025] See appendix Figure 5 The distributed optical fiber monitoring system (conventional monitoring method) employs pre-embedded optical fibers 12 for rapid screening of seepage areas. These fibers are pre-embedded in a serpentine pattern along the dam axis at the upstream impermeable concrete layer of dam body 1, with straight sections spaced 0.5 m apart. A DTS temperature-sensing optical cable is used, and thermal pulses are applied along the cable. Temperature rises rapidly in areas without seepage, while in areas with seepage, the temperature rises slowly due to heat being carried away by the water flow, with a temperature difference of 2-5℃. Continuous monitoring is achieved using micro-bending loss and distributed scattering, allowing for the identification of seepage sources and preliminary determination of approximate seepage locations.

[0026] The logic for identifying water sources is as follows: increased strain + decreased temperature + high-frequency AE indicates reservoir water infiltration (cold contraction effect); constant strain + increased temperature + low-frequency AE indicates mountain water outflow (thermal expansion effect). A serpentine spatial network layout utilizes distributed fiber optic 12 temperature sensing technology to capture the seepage-temperature coupling effect, and achieves layer spatial positioning through fiber optic 12 deployment, enabling monitoring of seepage locations across multiple compacted layers (e.g., ...). Figure 5 (Direction of the crack at point AA).

[0027] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An acoustic device for detecting liquid leakage, which descends from above a dam to a desired preset detection height using a miniature winch, characterized in that: The device includes a mobile vehicle connected to the output of a miniature winch via a flexible rope. A miniature cylinder is mounted on the mobile vehicle, and a sound wave detection mechanism is mounted downwards at the output of the miniature cylinder. This mechanism moves downwards to contact the detection surface. The sound wave detection mechanism includes a detector close to the detection surface. The detector is connected in sequence to a sound wave signal amplifier and a sound wave analysis device via a communication cable. The sound wave signal amplifier amplifies the weak sound wave signal and converts it into a digital signal. The sound wave analysis device determines the location and possible leakage channels through simulation analysis based on the strength, wavelength, and frequency characteristics of the sound wave.

2. The acoustic device for detecting liquid leakage according to claim 1, characterized in that: The detector is equipped with a soundproof cover, which consists of an arc-shaped soundproof layer, a damping buffer layer attached in the middle, and a sound-absorbing layer attached to the inner side, from the outside to the inside.

3. The acoustic device for detecting liquid leakage according to claim 2, characterized in that: The sound insulation layer can be made of 1-3mm thick steel plate, the middle damping buffer layer can be made of rubber, and the sound absorption layer can be made of sound-absorbing cotton.

4. The acoustic device for detecting liquid leakage according to claim 2, characterized in that: The bottom of the damping buffer layer expands outward in a ring shape to form a cushion layer, which uses a flexible sealing strip.

5. The acoustic device for detecting liquid leakage according to claim 3, characterized in that: The outermost rigid part of the soundproof cover is connected to the output end of the miniature cylinder. The detector is placed inside the soundproof cover and fastened to the lower side of the soundproof cover. The acoustic signal amplifier and acoustic analysis device are installed on the vehicle body outside the soundproof cover. The detector passes through the soundproof cover through a communication cable and is electrically connected to the acoustic signal amplifier and acoustic analysis device. The communication cable has a length surplus to achieve flexible hanging.

6. The acoustic device for detecting liquid leakage according to claim 5, characterized in that: The soundproof cover has openings and slots, and the openings and slots are covered with sealing caps made of flexible material.

7. The acoustic device for detecting liquid leakage according to claim 5, characterized in that: The thickness of the annular pad formed by circumferential expansion is increased, and the communication cable passes through the side of the annular pad.

8. The acoustic device for detecting liquid leakage according to claim 1, characterized in that: The preset detection height is determined using a distributed optical fiber monitoring system. This system uses pre-embedded optical fibers, which are embedded in a serpentine pattern along the dam axis in the upstream impermeable concrete layer of the dam body, with a straight section spacing of 0.5 m. A DTS temperature sensing optical cable is used to apply thermal pulses along the optical cable.

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