A hybrid temperature and vibration isolation device for distributed fiber optic acoustic wave sensing systems

Abstract

The present invention discloses a hybrid temperature and vibration isolation device for a distributed fiber optic acoustic wave sensing system. The distributed fiber optic acoustic wave sensing system includes a pulse generating module, which is used to set a pulse generating optical path. The device includes: a counterweight box, wherein a groove for setting the pulse generating module is opened at the top of the counterweight box, and vibration isolation material is arranged between the inner wall of the groove and the pulse generating module; an optical fiber and optical fiber device installation box, wherein the optical fiber and optical fiber device installation box is arranged above or below the counterweight box and is used to set the optical fiber optical path, and vibration isolation, heat preservation and sound absorption material is arranged in the optical fiber and optical fiber device installation box; a composite vibration isolation spring, wherein the composite vibration isolation spring is arranged on the outer surface of the counterweight box and is used to absorb vibration energy; wherein the pulse generating module is provided with vibration isolation and sound absorption material.

Description

Technical Field

[0001] The present application relates to the field of distributed optical fiber sensing, and in particular to a hybrid temperature and vibration isolation device applied to a distributed optical fiber acoustic wave sensing system. Background Art

[0002] Distributed fiber optic sensing (DOFS) is a sensing technology that uses the inherent scattering and structural properties of optical fibers to measure external parameters such as strain, temperature, and vibration. Due to the advantages of optical fiber, such as immunity to electromagnetic interference, high measurement accuracy, long sensing distance, and its ability to serve as both a communication carrier and a sensing medium, after decades of rapid development, numerous commercial instruments have been applied in fields such as geological monitoring, pipeline monitoring, bridge monitoring, and fire protection. Distributed fiber acoustic sensing (DAS) utilizes Rayleigh scattering in optical fibers for sensing. When pulsed light propagates through an optical fiber, it generates counter-propagating Rayleigh scattered light (RBS). The location of the Rayleigh scattered light can be determined by the time it takes for the Rayleigh scattered light to return to the input port. When an external sound wave acts on the optical fiber, the phase and amplitude of the RBS change accordingly. By measuring the amplitude or phase change of the RBS returning to the input port at different times, information about the sound wave detected at any location in the fiber can be obtained. Because the phase of Rayleigh scattered light is more sensitive to the external environment, phase-detection DAS offers superior performance. Phase detection is typically achieved using local interferometry techniques, such as Michelson interferometers and Mach-Zehnder interferometers.

[0003] In the process of implementing the present invention, the inventors discovered that the prior art has at least the following problems:

[0004] To reduce the system's detection noise floor, a section of reference optical fiber is placed inside the system to obtain a reference signal. However, the high-power computing chip and accompanying cooling fan in the system's circuits generate a wide range of temperature fluctuations and fan vibrations, which can cause vibration noise signals to be included in the Rayleigh signal in the reference optical path, which can also cause temperature drift. Furthermore, because the instrument operates in a noisy environment, such as on a ship, the vibration noise of the ship's turbines and brakes can introduce specific vibration signals into the reference optical fiber, which can degrade the effectiveness of the reference optical fiber.

[0005] The interferometric structure required for phase detection is also affected by the aforementioned external environmental vibrations and temperature drift. These effects can be compounded and superimposed on the system's detection signal, ultimately affecting the system's measurement of the acoustic waves sensed by the detection fiber, and thus, impacting system performance. Furthermore, fiber-optic distributed acoustic sensing systems typically consist of several components, including an optical module, a test data acquisition module, a signal processing module, and a control and display module. The pulse generation module includes active components such as lasers, optical modulators, fiber amplifiers, and related drivers, as well as passive components such as fiber couplers, circulators, and filters. These components and the optical path they form can also be affected by external vibrations, negatively impacting system performance. Therefore, when the device is used in an environment subject to significant vibration, vibration isolation and thermal insulation are necessary for key components and the optical path to improve the robustness of the system's loop. Summary of the Invention

[0006] In view of the problems existing in the prior art, the embodiment of the present application aims to provide a hybrid temperature and vibration isolation device for use in a distributed fiber optic acoustic wave sensing system.

[0007] According to a first aspect of an embodiment of the present application, a hybrid temperature and vibration isolation device for a distributed optical fiber acoustic wave sensing system is provided. The distributed optical fiber acoustic wave sensing system includes a pulse generating module, which is used to set a pulse generating optical path, including:

[0008] A counterweight box, wherein a groove for arranging the pulse generating module is opened on the top of the counterweight box, and vibration isolation materials are arranged between the inner wall of the groove and the pulse generating module;

[0009] An optical fiber and optical fiber device installation box, which is arranged above or below the counterweight box and is used to set the optical fiber light path. Vibration isolation, heat preservation and sound absorption materials are arranged in the optical fiber and optical fiber device installation box;

[0010] A composite vibration isolation spring, the composite vibration isolation spring being arranged on the outer surface of the counterweight box for absorbing vibration energy;

[0011] Wherein, the pulse generating module is provided with vibration isolation and sound absorption materials.

[0012] Furthermore, when the optical fiber and optical fiber device installation box is arranged above the counterweight box, the device also includes a fully enclosed shell of the vibration isolation system, and the counterweight box is arranged in the fully enclosed shell of the vibration isolation system through the composite vibration isolation springs on the four sides and the bottom surface, thereby forming a fully enclosed vibration isolation structure.

[0013] Furthermore, when the optical fiber and optical fiber device mounting box is arranged below the counterweight box, the device also includes a fixing cap, which is arranged in the upper middle part of the counterweight box and is detachably connected to the base plate of the distributed optical fiber acoustic wave sensing system through a fixing cap mounting leg, and there is a predetermined gap between the inner surface of the fixing cap and the head of the counterweight box.

[0014] Furthermore, the inner wall of the fixing cap is affixed with a material for vibration isolation, and vibration isolation columns are installed on the four corners.

[0015] Furthermore, one end of the composite vibration isolation spring is arranged at the bottom of the counterweight box, and the other end is arranged on the bottom plate of the distributed fiber optic acoustic wave sensing system. The optical fiber and optical fiber device installation box is arranged below the counterweight box and in the middle of the composite vibration isolation spring.

[0016] Furthermore, the counterweight box is a groove with a specific mass, and the specific mass is determined by the number of composite vibration isolation springs and the load capacity of the optimal elastic working area of ​​the composite vibration isolation springs. The pulse generating module is a "T"-shaped structure and is suspended in the groove of the counterweight box through the "T"-shaped structure. A fixed plate is also provided on the top of the pulse generating module, and the optical fiber and optical fiber device mounting box are installed on the fixed plate. The pulse generating module is a hollow hexahedron, and the vibration isolation material covers the four sides and bottom of the pulse generating module.

[0017] Furthermore, four straight holes of fixed size are opened at the four corners of the optical fiber and optical fiber device installation box, and four screw mounting holes are provided at corresponding positions on the fixing plate for fixing the optical fiber and optical fiber device installation box.

[0018] Furthermore, the bottom and four sides of the counterweight box are provided with screw mounting holes for fixing the composite vibration isolation spring.

[0019] Furthermore, the composite vibration isolation spring includes:

[0020] The damper is a viscous damper with a threaded through hole in the middle;

[0021] a spring isolator, wherein the damper is mounted within the spring isolator and does not contact the spring isolator;

[0022] a rubber vibration isolator, wherein the spring vibration isolator is mounted within the rubber vibration isolator and does not contact the rubber vibration isolator;

[0023] An upper mounting plate and a lower mounting plate, both ends of the damper, spring isolator and rubber isolator are respectively mounted on the upper mounting plate and the lower mounting plate;

[0024] Screw mounting holes. Two vibration isolation leg mounting holes are opened on the upper and lower mounting plates. A large screw through hole is opened in the center of the composite vibration isolation spring to completely fix and lock the vibration isolation system, so that the vibration isolation module will no longer shake during transportation, thereby extending the service life of the vibration isolation system during transportation.

[0025] Furthermore, the material used for vibration isolation in the vibration isolation and sound-absorbing material, vibration isolation material, and vibration isolation and heat-insulating sound-absorbing material is selected from one or more of cork, silicone, rubber, sponge latex, felt board, sponge, and foam board; the material used for heat insulation is organic heat insulation material and / or inorganic heat insulation material; and the material used for sound absorption is foam sound-absorbing material and / or fiber sound-absorbing material.

[0026] The technical solutions provided by the embodiments of the present application may have the following beneficial effects:

[0027] As can be seen from the above embodiments, the present application installs a composite vibration isolation spring on the counterweight box. The vibration isolation and damping effects of the composite vibration isolation spring absorb the vibration energy generated by bumps, impacts, braking, etc. on the outside of the chassis, thereby reducing the impact of the external drastic changes in the environment on the pulse generating module and the optical fiber optical path. The composite vibration isolation spring can effectively reduce the impact of large impacts on the optical path. At the same time, it can also filter out most of the energy in the mechanical vibration in the first layer, so that the optical path is basically guaranteed to be in a relatively vibration-free environment. In addition, it also protects the surrounding acquisition system, power supply system and data processing system from the impact of the shaking optical path module. Vibration isolation material is provided on the inner wall of the counterweight box groove, and vibration isolation and sound absorption material is provided in the pulse generating module. The use of two layers of material further reduces the impact of external vibration and the sound of the fan inside the chassis on the pulse generating module, providing a quasi-stable environment for the generation of pulses. Vibration-isolating, heat-insulating, and sound-absorbing materials are installed in the optical fiber and optical fiber device installation boxes. The use of this material not only further isolates the vibration and sound outside and inside the chassis, but also provides a constant temperature environment for the reference optical fiber, optical fiber devices, and interferometer. This setting not only solves the impact of external vibration and sound on the system, but also solves the temperature drift problem caused by rapid changes in external temperature, effectively improving the comprehensive stability of the working environment of the distributed optical fiber sensing system, and greatly improving the stability and adaptability of the system.

[0028] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0030] Figure 1The figure is a cross-sectional schematic diagram of a hybrid temperature and vibration isolation device (with a fixed cap structure) applied to a distributed fiber optic acoustic wave sensing system according to an exemplary embodiment.

[0031] Figure 2 It is a cross-sectional schematic diagram showing a hybrid temperature and vibration isolation device (fully enclosed vibration isolation structure) applied to a distributed fiber optic acoustic wave sensing system according to another exemplary embodiment.

[0032] Figure 3 1 is a diagram showing a thermal insulation and vibration isolation scheme for a heterodyne detection distributed fiber optic acoustic wave sensing system according to an exemplary embodiment.

[0033] Figure 4 It is a diagram showing a thermal insulation and vibration isolation scheme of a distributed fiber optic acoustic wave sensing system with a local interferometer according to another exemplary embodiment.

[0034] Figure 5 The figure shows the overall structure of a hybrid temperature and vibration isolation device (with a fixed cap structure) applied to a distributed fiber optic acoustic wave sensing system according to an exemplary embodiment.

[0035] Figure 6 FIG. 4 is a structural diagram of a fixing cap according to an exemplary embodiment.

[0036] Figure 7 The figure is a top view of a hybrid temperature and vibration isolation device (fully enclosed vibration isolation structure) applied to a distributed fiber optic acoustic wave sensing system according to an exemplary embodiment.

[0037] Figure 8 It is a schematic diagram of the overall structure of a composite vibration isolation spring according to an exemplary embodiment.

[0038] Figure 9 1 is a diagram showing the attachment structure of vibration-isolating and sound-absorbing materials and vibration-isolating and sound-absorbing heat-insulating materials according to an exemplary embodiment.

[0039] Description of reference numerals:

[0040] 1. Laser; 2. First fiber coupler; 3. Electro-optic modulator; 4. Acousto-optic modulator; 5. Optical amplifier; 6. Fiber circulator; 7. Second fiber coupler; 8. Balanced photodetector; 9. Reference optical fiber; 10. Avalanche detector; 11. Fiber optic Faraday rotator mirror; 12. Fixing cap; 13. Pulse generating module; 14. Counterweight box; 15. Composite vibration isolation spring; 151. Rubber vibration isolator; 152. Spring vibration isolator; 153. Upper mounting plate; 154. Damper; 155. Lower mounting plate; 16. Optical fiber and optical fiber device mounting box; 17. Fixing cap mounting leg; 18. Vibration isolation rubber layer; 19. Vibration isolation and sound-absorbing material; 20. Vibration isolation material; 21. Vibration isolation, heat preservation and sound-absorbing material; 22. Pulse generating optical path; 23. Straight slot hole; 24. Threaded hole; 25. Optical fiber and optical fiber device optical path; 26. Vibration isolation column mounting hole; 27. Vibration isolation system fully enclosed housing. DETAILED DESCRIPTION

[0041] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0042] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. As used in this application and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0043] It should be understood that although the terms first, second, third, etc. may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0044] An embodiment of the present application provides a hybrid thermal insulation and vibration isolation device for a distributed fiber optic acoustic wave sensing system, wherein the distributed fiber optic acoustic wave sensing system includes a pulse generating module 13, which is used to set a pulse generating optical path. The device includes a counterweight box 14, an optical fiber and optical fiber device mounting box 16, and a composite vibration isolation spring 15. The top of the counterweight box 14 is provided with a groove for setting the pulse generating module 13, and vibration isolation material 20 is provided between the inner wall of the groove and the pulse generating module 13; the optical fiber and optical fiber device mounting box 16 is arranged above or below the counterweight box 14 for setting the optical fiber optical path, and a vibration isolation, thermal insulation and sound-absorbing material 21 is provided in the optical fiber and optical fiber device mounting box 16; the composite vibration isolation spring 15 is arranged on the outer surface of the counterweight box 14 for absorbing vibration energy; wherein, a vibration isolation and sound-absorbing material 19 is provided in the pulse generating module 13.

[0045] As can be seen from the above embodiments, the present application installs a composite vibration isolation spring 15 on the counterweight box 14. The vibration isolation and damping effects of the composite vibration isolation spring 15 absorb the vibration energy generated by bumps, impacts, braking, etc. on the outside of the chassis, thereby reducing the impact of the external drastic changes in the environment on the pulse generating module 13 and the optical fiber optical path. The composite vibration isolation spring 15 can effectively reduce the impact of large impacts on the optical path. At the same time, it can also filter out most of the energy in the mechanical vibration in the first layer, so that the optical path is basically guaranteed to be in a relatively vibration-free environment. In addition, it also protects the surrounding acquisition system, power supply system and data processing system from the impact of the shaking optical path module. Vibration isolation material 20 is provided on the inner wall of the groove of the counterweight box 14, and vibration isolation and sound absorption material 19 is provided in the pulse generating module 13. The use of two layers of material further reduces the impact of external vibration and the sound of the fan inside the chassis on the pulse generating module 13, providing a quasi-stable environment for the generation of pulses. Vibration-isolating, heat-insulating, and sound-absorbing material 21 is provided in the optical fiber and optical fiber device installation box 16. The use of this material not only further isolates the vibration and sound from the outside and inside the chassis, but also provides a constant temperature environment for the reference optical fiber 9, optical fiber devices, and interferometer. This arrangement not only solves the impact of external vibration and sound on the system, but also solves the temperature drift problem caused by rapid changes in external temperature, effectively improving the overall stability of the working environment of the distributed optical fiber sensing system, and greatly improving the stability and adaptability of the system.

[0046] Figure 1 1 is a cross-sectional schematic diagram of a hybrid thermal insulation and vibration isolation device (with a fixing cap 12 structure) applied to a distributed optical fiber acoustic wave sensing system according to an exemplary embodiment. Figure 1As shown, when the optical fiber and optical fiber device mounting box 16 is arranged below the counterweight box 14, the device also includes a fixing cap 12, which is arranged in the upper middle part of the counterweight box 14 and is detachably connected to the bottom plate of the distributed optical fiber acoustic wave sensing system through a fixing cap mounting leg 17, and there is a certain gap between the inner surface of the fixing cap 12 and the head of the counterweight box 14. The inner wall of the fixing cap 12 is affixed with a material for vibration isolation, and vibration isolation columns are installed on the four corners. In a specific implementation, a straight slot hole 23 and a threaded hole 24 can be provided on the fixing cap mounting leg 17, and the fixing cap mounting leg 17 is connected to the bottom plate of the distributed optical fiber acoustic wave sensing system through a screw nut and a straight slot hole 23, and is connected to the fixing cap 12 through a screw and a threaded hole 24. The function of the fixing cap 12 is to limit the maximum displacement of the entire optical path module and remove the kinetic energy of the entire optical path module. Compared with using the composite vibration isolation spring 15 alone, the combination of the composite vibration isolation spring 15 and the fixing cap 12 can further reduce the impact of large impacts on the optical path. It can also filter out most of the energy in the mechanical vibration in the first level, so that the optical path is basically guaranteed to be in a relatively vibration-free environment. In addition, it also protects the surrounding acquisition system, power supply system and data processing system from the impact of the shaking optical path module.

[0047] Figure 2 FIG. 1 is a cross-sectional schematic diagram showing a hybrid thermal insulation and vibration isolation device (fully enclosed vibration isolation structure) applied to a distributed optical fiber acoustic wave sensing system according to an exemplary embodiment. Figure 2 As shown, when the optical fiber and optical fiber device installation box 16 is arranged above the counterweight box 14, the device also includes a vibration isolation system fully wrapped shell 27, and the counterweight box 14 is arranged in the vibration isolation system fully wrapped shell 27 through the composite vibration isolation spring 15 on the side wall and the bottom surface, thereby forming a fully enclosed vibration isolation structure.

[0048] Figure 3 and Figure 4 Two exemplary thermal insulation and vibration isolation schemes for distributed fiber optic acoustic wave sensing systems.

[0049] Figure 3 The structure in FIG. 1 includes a laser 1, a first fiber coupler 2, an electro-optic modulator 3, an acousto-optic modulator 4, an optical amplifier 5, a fiber circulator 6, a second fiber coupler 7, a balanced photodetector 8, and a reference fiber 9. The laser 1, fiber coupler, electro-optic modulator 3, acousto-optic modulator 4, and optical amplifier 5 within the dashed box A are all placed inside the pulse generation module 13 and, together with the internal drive circuit and temperature-vibration sensor, form a pulse generation optical path 22. The fiber circulator 6, fiber coupler, and reference fiber 9 within the dashed box B form an optical path 25 for optical fibers and optical fiber devices.

[0050] Figure 4 Overall structure and Figure 3Different, including laser 1, electro-optic modulator 3, acousto-optic modulator 4, optical amplifier 5, fiber circulator 6, fiber coupler, avalanche detector 10, Faraday reflector, the laser 1, electro-optic modulator 3, acousto-optic modulator 4 and optical amplifier 5 in the dotted box A are all placed inside the pulse generating module 13, and together with the internal driving circuit and temperature-vibration sensor constitute the pulse generating optical path, the fiber circulator 6, fiber coupler, reference fiber 9 and Faraday reflector inside the dotted box B are the optical path 25 of optical fiber and optical fiber device.

[0051] Specifically, the optical fiber and optical fiber device mounting box 16 is used to house the reference optical fiber 9, interference optical path, and optical fiber devices in the distributed optical fiber acoustic wave sensing optical path, including but not limited to the optical fiber optical path and passive optical fiber devices that are susceptible to vibration, as shown within the dotted box B in Figures 3 and 4. Multiple layers of vibration-isolating, sound-absorbing, and heat-insulating material are adhered to the interior of the box. The reference optical fiber 9 and optical fiber devices are filled with multiple layers of vibration-isolating, sound-absorbing, and heat-insulating material and pressed tightly against the interior of the optical fiber and optical fiber device mounting box 16 with a certain force. This ensures that the reference optical fiber 9 and optical fiber device optical path are stabilized to the maximum extent possible while ensuring that the reference optical fiber 9 and optical fiber device optical path are not damaged, ensuring that the optical fiber and optical fiber device optical path 25 can operate in a silent, vibration-free, and constant temperature environment, thereby achieving the purpose of improving system performance. The bottom of the optical fiber and optical fiber device mounting box 16 has screw mounting holes and optical fiber and optical fiber device fixing buckles. Two notches larger than the diameter of the optical fiber are opened on both sides of the box for the introduction and removal of optical fiber and optical fiber devices.

[0052] In an embodiment of a fixing cap 12 solution, as shown in FIG. Figure 5 As shown, one end of the composite vibration isolation spring 15 is mounted on the base plate of the distributed fiber optic acoustic wave sensing system, and the other end is mounted on the bottom surface of the counterweight box 14. An optical fiber and fiber optic device mounting box 16 is placed below the counterweight box 14 and between the composite vibration isolation spring 15. A pulse generator module 13 is placed in a groove in the counterweight box 14. A fixing cap 12 is mounted on the top of the counterweight box 14, and the fixing cap 12 is attached to the base plate of the distributed fiber optic acoustic wave sensing system via fixing cap mounting legs 17. This structural design ensures compactness while providing multi-level vibration isolation, sound absorption, and thermal insulation, maximizing the effectiveness and stability of the distributed fiber optic sensing system.

[0053] In one embodiment, four composite vibration isolation springs 15 are evenly installed at the four corners of the bottom of the counterweight box 14. The height of the vibration isolation springs is higher than the optical fiber and optical fiber device installation box 16 to ensure that the optical fiber and optical fiber device installation box 16 are installed at a certain distance from the bottom plate of the distributed optical fiber sensing instrument when installed at the bottom of the counterweight box 14. The other ends of all the composite vibration isolation springs 15 are installed on the bottom plate of the distributed optical fiber sensing system.

[0054] Specifically, the bottom of the counterweight box 14 has screw mounting holes for securing the composite vibration isolation spring 15. Vibration isolation material 20 is adhered to each surface of the inner wall of the groove of the counterweight box 14. The counterweight box 14 serves to secure the pulse generating module 13, provide a base weight for the composite vibration isolation spring 15 to achieve a better vibration isolation effect, and secure the optical fiber and optical fiber component mounting box 16.

[0055] Specifically, the counterweight box 14 is a recessed groove with a specific mass, determined by the number of composite vibration isolation springs 15 and the load capacity of the composite vibration isolation springs 15 within their optimal elastic working range. The pulse generator module 13 has a hollow T-shaped housing with vibration isolation material 20 and sound-absorbing material attached to the inner wall. A pulse generation optical path 22, consisting of a driver circuit board, a laser 1, an electro-optical modulator 3, an acousto-optic modulator 4, and a temperature and vibration monitoring module, is then installed. The pulse generator module 13 is primarily used to generate specially modulated detection light pulse signals. Multiple layers of vibration isolation material 20 separate the T-shaped housing of the pulse generator module 13 and the inner wall of the counterweight box 14. The pulse generator module 13 is suspended within the recessed groove of the counterweight box 14 via the T-shaped structure. When assembled, the T-shaped structure of the pulse generator module 13 and the counterweight box 14 form a complete rectangular parallelepiped, creating a more aesthetically pleasing overall structure and facilitating disassembly and assembly of the pulse generator module 13. A fixing plate is also provided on the top of the pulse generating module 13 , and the optical fiber and optical fiber device mounting box 16 are mounted on the fixing plate. The pulse generating module 13 is a hollow hexahedron, and the vibration isolation material 20 covers the four sides and the bottom of the pulse generating module 13 .

[0056] In another embodiment of the fully enclosed vibration isolation structure, as shown in FIG. Figure 2 and Figure 7 As shown, the counterweight box 14 is connected to the fully wrapped housing 27 of the vibration isolation system with composite vibration isolation springs 15 on all sides and the bottom. By using the composite vibration isolation springs 155 to isolate vibrations in all directions, vibrations from all directions can be greatly attenuated, while ensuring the stability of the relative position of the entire optical path. The pulse generating module 13 adopts a "T"-shaped structure. The pulse generating module 13 is suspended in the groove of the counterweight box 14. The vibration isolation material 20 is filled between the pulse generating module 13 and the groove. The structure has a large vibration buffering stroke in the vertical direction, which can minimize the vibration in the vertical direction; the optical fiber and optical fiber device mounting box 16 is fixed to the mounting hole on the top of the pulse generating module 13, wherein Figure 3 and Figure 4 The optical fiber and optical fiber components contained in the dotted box B are installed in the box 16 and are filled and fixed by the vibration isolation, sound insulation and heat preservation materials in the box.

[0057] In a specific implementation, four straight holes of fixed size are opened at the four corners of the optical fiber and optical fiber device installation box 16, and four screw mounting holes are provided at corresponding positions on the fixing plate. The screws pass through the straight holes and the screw mounting holes in turn and are installed on the fixing plate, thereby fixing the optical fiber and optical fiber device installation box 16.

[0058] Specifically, if Figure 8 As shown, the composite vibration isolation spring 15 includes a damper 154, a spring vibration isolator 152, a rubber vibration isolator 151, an upper mounting plate 153 and a lower mounting plate 155. The damper 154 is installed in the spring vibration isolator 152; the spring vibration isolator 152 is installed in the rubber vibration isolator 151; and both ends of the damper 154, the spring vibration isolator 152 and the rubber vibration isolator 151 are respectively installed on the upper mounting plate 153 and the lower mounting plate 155.

[0059] In practice, the composite vibration isolation spring 15 comprises a rubber isolator 151, a spring isolator 152, a damper 154, an upper mounting plate 153, and a lower mounting plate 155. This composite structure effectively utilizes both the spring's shock-absorbing and rubber's vibration-isolating properties, while also leveraging the damping effect of the damper 154. This composite vibration isolation spring 15 can provide both bump and impact protection and vibration isolation. The damper 154 is positioned within the spring isolator 152 and does not contact it. Its ends are directly connected to the upper and lower mounting plates 153 and 155. The spring isolator 152 is positioned within the rubber isolator 151 and does not contact it. Its ends are directly connected to the upper and lower mounting plates, primarily serving to isolate low-frequency vertical vibrations. The rubber isolator 151 is directly connected to the mounting plate, effectively absorbing high-frequency vertical vibration energy. The upper and lower mounting plates 153 and 155 have large and small annular grooves and circular grooves for securing the rubber isolator 151, spring isolator 152, and damper 154. The upper and lower mounting plates have through-holes for screws to secure the composite isolation spring 15. A through-hole between the damper 154 and the upper and lower mounting plates 155 is used to insert screws and rivets to secure the entire distributed optical fiber thermal insulation and vibration isolation system. This ensures that the isolation system is protected from damage during transportation and even from heavy impact, extending its service life.

[0060] Specifically, the vibration-isolating and sound-absorbing materials 19, the vibration-isolating and heat-insulating sound-absorbing materials 21 are made of materials selected from one or more of silica gel, rubber, sponge, and foam board. The sound-absorbing materials are organic fiber sound-absorbing materials, inorganic fiber sound-absorbing materials, and / or inorganic foam sound-absorbing materials. The heat-insulating materials are organic heat-insulating materials and / or inorganic heat-insulating materials. The optical fiber and optical fiber device mounting box 16 is filled in the form of a filling. In a specific implementation, the vibration-isolating material 20 on the inner wall of the counterweight box 14 is attached to the groove of the counterweight box 14 in a "sandwich" structure. The specific structure can be referred to. Figure 9 Structural diagram, where A1, A2, B1, B2, C1, C2 can represent vibration isolation materials 20 or sound absorbing materials or thermal insulation materials with different performances, in order to achieve better vibration isolation, sound absorption and thermal insulation performance, ensuring that the entire optical path is in an optimal state.

[0061] The working principle of a hybrid vibration isolation device for a distributed fiber optic acoustic wave sensing system provided by the present application is as follows: first, a composite vibration isolation spring is used to fix the counterweight box 14 on the bottom plate of the instrument case. When vibration and impact act on the instrument case, the composite vibration isolation spring 15 attenuates the external vibration to a lower level for the first time through vibration reduction and damping. Then, the vibration isolation material 20 attached to the inner wall of the counterweight box 14 further reduces the vibration transmitted to the pulse generating module 13. At the same time, the vibration isolation and sound absorbing materials in the pulse generating module 13 can block the vibration introduced by the cooling fan and external sound, ensuring that the pulse generating optical path 22 can work in a relatively quiet environment. The optical fiber and optical fiber device mounting box 16 fixed on the upper or bottom of the counterweight box 14 are filled with vibration isolation, heat preservation and sound absorbing materials 2. 1. The optical fiber and optical fiber device optical path 25 are firmly pressed into the optical fiber and optical fiber device installation box 16. Through the multiple vibration absorption, sound absorption and heat preservation effects of the composite vibration isolation spring 15 and the vibration isolation material 20, the interference optical path with extremely high sensitivity can be minimally affected. Finally, the fixed cap 12 structure composed of the fixed cap 12, the vibration isolation material 20 and the fixed cap installation leg 17 is used to limit the maximum displacement of the optical path, thereby protecting the vibration isolation structure and the circuits and control systems around the vibration isolation system. Finally, the hybrid vibration isolation system composed of the vibration isolation cap, the pulse generating module 13, the counterweight box 14, the composite vibration isolation spring 15 and the optical fiber and optical fiber device installation box provides a stable and shock-resistant working environment for the distributed optical fiber sensing system, reduces the environmental noise of the system, and thus realizes the adaptability of the system to complex environments.

[0062] Those skilled in the art will readily conceive of other embodiments of the present application after considering the specification and practicing the contents disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present application that follow the general principles of this application and include common knowledge or customary techniques in the art that are not disclosed in this application.

[0063] It will be understood that the present application is not limited to the exact construction that has been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof.

Claims

1. A hybrid temperature and vibration isolation device for a distributed fiber optic acoustic wave sensing system, wherein the distributed fiber optic acoustic wave sensing system comprises a pulse generating module, wherein the pulse generating module is used to set a pulse generating optical path, wherein: include: A counterweight box, wherein a groove for arranging the pulse generating module is opened on the top of the counterweight box, and vibration isolation materials are arranged between the inner wall of the groove and the pulse generating module; An optical fiber and optical fiber device installation box, which is arranged above or below the counterweight box and is used to set the optical fiber light path. Vibration isolation, heat preservation and sound absorption materials are arranged in the optical fiber and optical fiber device installation box; A composite vibration isolation spring, the composite vibration isolation spring being arranged on the outer surface of the counterweight box for absorbing vibration energy; In which, the pulse generating module is provided with vibration isolation and sound absorption material; the counterweight box is a groove with a specific mass, and the specific mass is determined by the number of composite vibration isolation springs and the load capacity of the optimal elastic working area of ​​the composite vibration isolation spring. The pulse generating module is a "T"-shaped structure and is suspended in the groove of the counterweight box through the "T"-shaped structure. A fixing plate is also provided on the top of the pulse generating module, and the optical fiber and optical fiber device mounting box are mounted on the fixing plate. The pulse generating module is a hollow hexahedron, and the vibration isolation material covers the four sides and bottom of the pulse generating module; The composite vibration isolation spring can prevent bumps and shocks and achieve the function of vibration isolation, including: The damper is a viscous damper with a threaded through hole in the middle; A spring vibration isolator, wherein the damper is installed inside the spring vibration isolator and does not contact the spring vibration isolator, and is used to isolate low-frequency vibration in the vertical direction; A rubber vibration isolator, wherein the spring vibration isolator is installed inside the rubber vibration isolator and does not contact the rubber vibration isolator, and is used to absorb high-frequency vibration energy in the vertical direction; An upper mounting plate and a lower mounting plate, both ends of the damper, spring isolator and rubber isolator are respectively mounted on the upper mounting plate and the lower mounting plate; Screw mounting holes: There are two vibration isolation leg mounting holes on the upper and lower mounting plates. A large screw through hole is opened in the center of the composite vibration isolation spring to completely fix and lock the vibration isolation system, so that the vibration isolation module will not shake during transportation, thereby extending the service life of the vibration isolation system during transportation; Among them, the material used for vibration isolation in the vibration isolation and sound absorbing material, vibration isolation material, vibration insulation and sound absorbing material is selected from one or more of cork, silica gel, rubber, sponge latex, felt board, sponge, and foam board; the material used for heat insulation is organic heat insulation material and / or inorganic heat insulation material; the material used for sound absorption is foam sound absorbing material and / or fiber sound absorbing material.

2. The device according to claim 1, characterized in that When the optical fiber and optical fiber device installation box is arranged above the counterweight box, the device also includes a fully enclosed shell of the vibration isolation system. The counterweight box is arranged in the fully enclosed shell of the vibration isolation system through the composite vibration isolation springs on the four sides and the bottom surface, thereby forming a fully enclosed vibration isolation structure.

3. The device according to claim 1, characterized in that When the optical fiber and optical fiber device mounting box is arranged below the counterweight box, the device also includes a fixing cap, which is arranged in the upper middle part of the counterweight box and is detachably connected to the base plate of the distributed optical fiber acoustic wave sensing system through the fixing cap mounting legs, and there is a predetermined gap between the inner surface of the fixing cap and the head of the counterweight box.

4. The device according to claim 3, characterized in that The inner wall of the fixing cap is affixed with a material for vibration isolation, and vibration isolation columns are installed on the four corners.

5. The device according to claim 3, characterized in that One end of the composite vibration isolation spring is arranged at the bottom of the counterweight box, and the other end is arranged on the bottom plate of the distributed optical fiber acoustic wave sensing system. The optical fiber and optical fiber device installation box is arranged below the counterweight box and in the middle of the composite vibration isolation spring.

6. The device according to claim 1, characterized in that The optical fiber and optical fiber device installation box has four straight holes of fixed size at the four corners, and the fixing plate has four screw mounting holes at corresponding positions for fixing the optical fiber and optical fiber device installation box.

7. The device according to claim 1, characterized in that The bottom and four sides of the counterweight box are provided with screw mounting holes for fixing the composite vibration isolation spring.

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