Deep sea seismic node receiving piezoelectric geophone

Abstract

The embodiment of the present application provides a deep-sea seismic node receiving piezoelectric detector, which comprises a vibration sensing component, a connecting piece, a sealing layer and an external lead wire, the sealing layer is bonded with the connecting piece to form a closed cavity, the vibration sensing component is arranged in the cavity, the vibration sensing component comprises at least four piezoelectric ceramic round tubes, the piezoelectric ceramic round tubes are sequentially stacked in the axial direction, and the piezoelectric ceramic round tubes are separated by a middle lining, end covers are arranged at two ends of the piezoelectric ceramic round tube string group, a supporting rod is arranged between the two end covers, and the piezoelectric ceramic round tube is electrically connected with the external lead wire through an electrode. The piezoelectric detector adopts at least four piezoelectric ceramic tubes stacked in the axial direction to form a piezoelectric ceramic round tube string group, the free capacitance of the detector is increased, and the sensitivity consistency of the piezoelectric detector can be conveniently controlled, meanwhile, the supporting rod and the two end covers form a supporting structure, the supporting structure can enhance the radial and axial hydrostatic pressure resistance of the cylindrical structure, so that the use performance of the piezoelectric detector in the deep sea is ensured.

Description

Technical Field

[0001] This invention relates to the field of deep-sea seismic exploration receiving sensor technology, and in particular to a deep-sea seismic node receiving piezoelectric detector. Background Technology

[0002] With social progress and economic development, the world's demand for oil is increasing. The ratio of land to sea area on Earth is approximately 7:3. Compared to land, the ocean contains far more abundant oil resources, making offshore oil exploration the primary target of modern oil exploration.

[0003] Currently, most offshore oil exploration is concentrated in waters only tens to hundreds of meters deep, leaving much to be done for exploration in depths exceeding one thousand meters. Seafloor node acquisition is the primary equipment for deep-sea seismic exploration, requiring data acquisition from four azimuths. A node acquisition station is equipped with three omnidirectional land geophones and one piezoelectric geophone. The piezoelectric geophone receives vertically emitted P-wave data, which is the most commonly used seismic exploration data. Therefore, the performance of the piezoelectric geophone is crucial for oil and gas exploration and development. Existing research on piezoelectric geophones mainly focuses on land-based piezoelectric geophones or accelerometers, with only a small portion focusing on marine piezoelectric geophones. Research on piezoelectric geophones for deep-sea applications (those exceeding one thousand meters) is even less. Current piezoelectric geophone technology cannot meet the requirements for operation at depths exceeding one thousand meters, where it must withstand high hydrostatic pressure. Summary of the Invention

[0004] In view of this, to address the need for piezoelectric detectors to withstand high hydrostatic pressure in deep-sea environments exceeding 1,000 meters, this invention provides a deep-sea seismic node receiving piezoelectric detector.

[0005] This invention provides a deep-sea seismic node receiving piezoelectric detector, comprising: a vibration sensing component, a connector, a sealing layer, and an external wire;

[0006] The sealing layer is bonded to the connector to form a sealed cavity; the vibration sensing component is placed inside the cavity, and the external wire passes through the connector and is electrically connected to the vibration sensing component.

[0007] The vibration sensing component includes: a string of piezoelectric ceramic cylindrical tubes, a middle liner, end liners, a support rod, a first end cap, a second end cap, and two electrodes; the middle liner and the end liners are made of insulating material; wherein...

[0008] The piezoelectric ceramic tube string assembly includes at least four piezoelectric ceramic tubes, which are stacked sequentially along the axial direction, and the intermediate liner is provided between two adjacent piezoelectric ceramic tubes; the two ends of the piezoelectric ceramic tube string assembly are connected to the end liners.

[0009] One end of the piezoelectric ceramic round tube string group is provided with the first end cover, and the other end is provided with the second end cover; the end liner separates the piezoelectric ceramic round tube string group from the first end cover and the second end cover; one end of the connecting piece close to the sealing layer is in abutment with the first end cover;

[0010] The support rod axially penetrates the middle liner and the end liner along the piezoelectric ceramic round tube string group, and the two ends of the support rod are fixedly connected with the first end cover and the second end cover respectively;

[0011] The two electrodes are inserted into the first end cover, and the piezoelectric ceramic round tube string group is electrically connected with the two electrodes; the two electrodes are connected with the external lead wire.

[0012] Optionally, in the case that the piezoelectric ceramic round tube string group includes four piezoelectric ceramic round tubes, the four piezoelectric ceramic round tubes are radially polarized;

[0013] Two of the piezoelectric ceramic round tubes are polarized outwardly and connected in parallel by lead wires to form a first string group; the other two piezoelectric ceramic round tubes are polarized inwardly and connected in parallel by lead wires to form a second string group; the first string group and the second string group are connected in series by lead wires and connected with the two electrodes.

[0014] Optionally, the first end cover and the second end cover are provided with mounting holes opposite to each other on one side close to the piezoelectric ceramic round tube string group, and the two ends of the support rod are inserted and fixed with the mounting holes.

[0015] Optionally, one end of the connecting piece close to the first end cover is provided with a recess, and the electrode is placed in the recess of the connecting piece.

[0016] Optionally, the middle liner and the end liner are made of any one of epoxy foam, rigid polyurethane foam and nano-composite foam.

[0017] Optionally, the sealing layer is made of any one of epoxy resin, polyurethane, silicone rubber, fluorine rubber and fluorosilicone rubber, and is used for external sealing of the piezoelectric detector.

[0018] Optionally, the support rod is made of metal material or high-hardness non-metal material.

[0019] Optionally, the support rod is made of any one of stainless steel, iron, copper and pressure-resistant ceramic.

[0020] Optionally, the electrode is made of any one of copper alloy or Kovar alloy.

[0021] Optionally, the connecting piece is made of any one of hard aluminum alloy, stainless steel alloy and copper alloy.

[0022] Compared with the prior art, the present application has the following advantages:

[0023] In the embodiment of the present application, the deep-sea seismic node receiving piezoelectric detector adopts at least four piezoelectric ceramic round tubes which are stacked in sequence in the axial direction to form a piezoelectric ceramic round tube group, thereby increasing the free capacitance of the detector, and the structure formed by the at least four piezoelectric ceramic round tubes facilitates better control of the sensitivity consistency of the piezoelectric detector; in terms of structure, the support of the upper two end covers by the support rod enhances the axial hydrostatic pressure resistance of the piezoelectric detector, and the use of the middle lining and the end lining plays the role of a rib, which can enhance the radial hydrostatic pressure resistance of the cylindrical structure. Through the above design, the hydrostatic pressure resistance of the piezoelectric detector can be effectively improved, and the sensitivity of the detector can be improved, thereby ensuring that the piezoelectric detector can be effectively used in deep sea. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a structural schematic diagram of a deep-sea seismic node receiving piezoelectric detector provided by the embodiment of the present application;

[0025] Figure 2 is a structural schematic diagram of a vibration sensing assembly of a piezoelectric detector provided by the embodiment of the present application;

[0026] Figure 3 is a circuit connection schematic diagram of a deep-sea seismic node receiving piezoelectric detector provided by the embodiment of the present application;

[0027] Figure 4 is a receiving sensitivity detection result schematic diagram of a deep-sea seismic node receiving piezoelectric detector provided by the embodiment of the present application. DETAILED DESCRIPTION

[0028] In order to make the above-mentioned objects, features and advantages of the present application more apparent and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0029] Although the preferred embodiments of the present application have been described, those skilled in the art can make further changes and modifications to the embodiments once they know the basic inventive concept. Therefore, the appended claims are intended to be interpreted as including all changes and modifications falling within the scope of the embodiments of the present application.

[0030] In the description of this invention, it should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0031] Before explaining the piezoelectric detector for deep-sea seismic nodes provided in the embodiments of the present invention, the application scenarios of the piezoelectric detector for deep-sea seismic nodes provided in the embodiments of the present invention will be specifically described:

[0032] Seafloor node acquisition is a key piece of equipment for deep-sea seismic exploration, requiring data acquisition from four azimuths. A node acquisition station is equipped with three omnidirectional land geophones and one piezoelectric geophone. The piezoelectric geophone receives vertically emitted P-wave data, which is the most commonly used seismic exploration data. Therefore, the performance of the piezoelectric geophone is crucial for oil and gas exploration and development. In China, research on piezoelectric geophones mainly focuses on land-based piezoelectric geophones or accelerometers, with only a small portion focusing on marine piezoelectric geophones. Furthermore, research on piezoelectric geophones used in deep-sea applications (above 1000 meters, 2000-3000 meters) is even less extensive.

[0033] The ratio of land to sea area on Earth is approximately 7:3. Compared to land, the ocean contains far more abundant oil resources. However, most of China's current offshore oil exploration is concentrated in waters only tens to hundreds of meters deep, leaving exploration in areas deeper than 1,000 meters insufficient. In the ocean, pressure increases with depth; on average, every 10 meters of depth increases the pressure by one atmosphere. For example, at 1,000 meters on the seabed, the pressure is approximately 100 atmospheres. Existing piezoelectric detectors used in deep-sea environments are prone to damage to their core vibration sensing components under high hydrostatic pressure. Furthermore, existing piezoelectric detectors have poor anti-interference capabilities in deep-sea applications, failing to meet the required detection sensitivity.

[0034] The piezoelectric detector for deep-sea seismic nodes provided in this application will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0035] Figure 1 This is a schematic diagram of the structure of a deep-sea seismic node receiving piezoelectric detector provided in an embodiment of the present invention.Figure 2 is a structural schematic diagram of a vibration sensing assembly of a piezoelectric detector provided by an embodiment of the present application, wherein, Figure 2 is Figure 1 is a structural schematic diagram of part A in the dashed box.

[0036] As shown in Figure 1 and Figure 2 , the deep-sea seismic node receiving piezoelectric detector can specifically include: a vibration sensing assembly A, a connecting piece 8, a sealing layer 10, and an external lead wire 9, the sealing layer 10 is bonded with the connecting piece 8 to form a closed cavity, the vibration sensing assembly A is placed in the cavity, the sealing layer 10 is wrapped on the outside of the vibration sensing assembly A, and the external lead wire 9 is electrically connected with the vibration sensing assembly A through the connecting piece 8. The vibration sensing assembly A includes: a piezoelectric ceramic round tube string group 1, a middle liner 2, an end liner 3, a support rod 4, a first end cover 5, a second end cover 6, and two electrodes 7, the middle liner and the end liner are made of insulating material, wherein the piezoelectric ceramic round tube string group 1 includes at least four piezoelectric ceramic round tubes, at least the four piezoelectric ceramic round tubes are sequentially stacked in the axial direction, the middle liner 2 is arranged between adjacent two piezoelectric ceramic round tubes, the two ends of the piezoelectric ceramic round tube string group 1 are connected with the end liner 3, one end of the piezoelectric ceramic round tube string group 1 is provided with the first end cover 5, and the other end is provided with the second end cover 6, the end liner 3 separates the piezoelectric ceramic round tube string group 1 from the first end cover 5 and the second end cover 6, one end of the connecting piece 8 close to the sealing layer 10 abuts against the first end cover 5, the support rod 4 penetrates the middle liner 2 and the end liner 3 in the axial direction of the piezoelectric ceramic round tube string group, the two ends of the support rod 4 are fixedly connected with the first end cover 5 and the second end cover 6 respectively, the two electrodes 7 are inserted into the first end cover 5, the piezoelectric ceramic round tube string group 1 is electrically connected with the two electrodes 7, and the two electrodes 7 are connected with the external lead wire 9.

[0037] In the embodiment of the present application, the vibration sensing assembly A is used for picking up the node vibration signal, and collecting the data of the vertically emitted longitudinal wave, the vibration sensing assembly A includes: a piezoelectric ceramic round tube string group 1, a middle liner 2, an end liner 3, a support rod 4, a first end cover 5, a second end cover 6, and two electrodes 7, wherein the piezoelectric ceramic round tube string group 1 includes at least four piezoelectric ceramic round tubes, at least four ceramic tubes are sequentially stacked in the axial direction, the middle liner 2 made of insulating material is used to separate adjacent two piezoelectric ceramic round tubes, so as to play the role of insulation between the adjacent two piezoelectric ceramic round tubes, the two ends of the piezoelectric ceramic round tube string group 1 are connected with the first end cover 5 and the second end cover 6 respectively, and the end liner 3 made of insulating material is arranged between the piezoelectric ceramic round tube string group 1 and the first end cover 5 and the second end cover 6, so as to play the role of insulation between the piezoelectric ceramic round tube string group 1 and the first end cover 5 and the second end cover 6.

[0038] It should be noted that in the embodiment of the present application, the piezoelectric ceramic tube string group comprises at least four piezoelectric ceramic tubes, and the number of piezoelectric ceramic tubes is an even number, for example, six piezoelectric ceramic tubes, eight piezoelectric ceramic tubes, etc. The plurality of piezoelectric ceramic tubes are stacked in the axial direction to form the piezoelectric ceramic tube string group. In use, different circuit connection modes between the piezoelectric ceramic tubes can be set as needed, so as to facilitate the control of the consistency of the sensitivity of the piezoelectric detector.

[0039] In the embodiment, the piezoelectric ceramic tube string group 1 is composed of at least four piezoelectric ceramic tubes stacked in the axial direction to form a ceramic tube string. The free capacitance of the detector can be effectively increased, the detection sensitivity of the detector in deep sea can be improved, and the piezoelectric ceramic tube string group 1 in a tubular structure can effectively resist hydrostatic pressure.

[0040] Further, a plurality of piezoelectric ceramic tubes with the same size and the same material can be selected to form the piezoelectric ceramic tube. The piezoelectric ceramic tube can be made of lead zirconate titanate material. Alternatively, the material of the piezoelectric ceramic tube is pzt-4, pzt-5, pzt-8, etc. The embodiment of the present application does not limit this.

[0041] Alternatively, the end liner 3 and the middle liner 2 can be made of foam insulation material, which can not only play an insulating role between adjacent two piezoelectric ceramic tubes and between the piezoelectric ceramic tube and the end cover, but also can play a buffering protection role on the piezoelectric ceramic tube. When the piezoelectric ceramic tube string group 1 is subjected to hydrostatic pressure in the axial direction, the end liner 3 and the middle liner 2 are deformed to release the hydrostatic pressure, thereby playing a protection role on the piezoelectric ceramic tube.

[0042] The end liner 3 and the middle liner 2 can be made of epoxy foam, hard polyurethane foam, nano composite foam, etc., thereby playing a role of vibration decoupling between the piezoelectric ceramic tubes and releasing the radial hydrostatic pressure of the detector.

[0043] Further, the middle liner 2 can be shaped as thin at the outer edge and thick in the middle, so that a limiting platform structure is formed between the outer edge part and the middle part. The limiting platform structure is arranged on both sides of the middle liner 2 close to the two side walls of the piezoelectric ceramic tube. The piezoelectric ceramic tube abuts against the limiting platform structure, thereby forming radial support on both ends of the piezoelectric ceramic tube. Through the coaxial cooperation of the plurality of middle liners 2, the radial hydrostatic pressure releasing capability of the cylindrical structure of the piezoelectric ceramic tube string group 1 is improved, thereby playing a role of improving the pressure resistance performance of the detector.

[0044] Alternatively, the end liner 3 close to the piezoelectric ceramic tube is shaped as thin at the outer edge and thick in the middle, so that a limiting platform structure is formed between the outer edge part and the middle part. The piezoelectric ceramic tube abuts against the limiting platform structure at one end. Through the coaxial cooperation of the end liner 3 and the middle liner 2, the radial hydrostatic pressure releasing capability of the cylindrical structure of the piezoelectric ceramic tube string group 1 is improved, thereby playing a role of improving the pressure resistance performance of the detector.

[0045] Optionally, the first end cover 5 and the second end cover 6 can be made of metal materials such as stainless steel, iron, copper, etc., or high-hardness non-metal materials such as pressure-resistant ceramic, etc. In use, the second end cover 6 can release the axial hydrostatic pressure of the geophone, thereby improving the axial pressure resistance of the geophone.

[0046] In the embodiment, the inside of the piezoelectric ceramic round tube string 1 is provided with a support rod 4 penetrating through in the axial direction, the middle parts of the end liner 3 and the middle liner 2 are respectively provided with through holes, the support rod 4 passes through the through holes of the end liner 3 and the middle liner 2, and the two ends of the support rod 4 are respectively fixedly connected with the first end cover 5 and the second end cover 6. The first end cover 5 and the second end cover 6 and the support rod 4 form a support structure, thereby reducing the axial hydrostatic pressure of the piezoelectric ceramic round tube, and effectively improving the axial hydrostatic pressure resistance of the geophone.

[0047] In the embodiment, the insertion and fixation between the support rod 4 and the first end cover 5 and the second end cover 6 can be adhesive fixation, clamping fixation, threaded fixation, etc.

[0048] Optionally, the middle parts of the first end cover 5 and the second end cover 6 on the side close to the piezoelectric ceramic round tube string 1 are respectively provided with mounting holes, the two ends of the support rod 4 are inserted into the mounting holes and are fixed by adhesive, and it should be noted that the adhesive can be any one of epoxy resin adhesive, unsaturated polyester resin adhesive, phenolic resin adhesive, polyacrylic resin adhesive and polyvinyl chloride resin adhesive, which can be selected according to actual needs by those skilled in the art, and the embodiment of the present application does not limit this.

[0049] Optionally, the middle parts of the first end cover 5 and the second end cover 6 on the side close to the piezoelectric ceramic round tube string 1 are respectively provided with mounting holes, the inner side wall of the mounting hole is provided with an internal thread, and the two ends of the support rod 4 are provided with an external thread. In mounting, the metal support rod 4 is fixed by threaded connection with the first end cover 5 and the second end cover 6.

[0050] Optionally, the support rod 4 can be made of metal materials such as stainless steel, iron, copper, etc., or high-hardness non-metal materials such as pressure-resistant ceramic, etc. The support rod 4 is used for supporting the first end cover 5 and the second end cover 6, thereby improving the axial pressure resistance of the first end cover 5 and the second end cover 6.

[0051] In the embodiment, the first end cover 5 is provided with two through holes, two electrodes 7 are inserted and fixed to the first end cover 5 through the through holes, the positive and negative poles of the piezoelectric ceramic round tube string 1 are connected with the two electrodes 7 through wires, the two electrodes 7 are electrically connected with an external wire 9, and the external wire 9 can be connected with a signal receiving module of an ocean node, thereby transmitting the signal data received by the piezoelectric geophone to the signal receiving module of the ocean node.

[0052] Optionally, the two through holes on the first end cover 5 are respectively composed of two concentric circular holes arranged along the axial direction of the first end cover, wherein the outer diameter of the circular hole close to the connecting piece is larger than the outer diameter of the circular hole close to one end of the piezoelectric ceramic tube string group, and a clamping platform is formed at the intersection of the concentric circular holes; the two electrodes are provided with protruding portions on the circumferential side wall, and the protruding portions are clamped and engaged with the clamping platform, so as to fix and connect the electrodes on the first end cover.

[0053] Optionally, the two electrodes 7 and the through holes between the first end cover 5 can be further bonded and fixed by using an adhesive, which can be any one of an epoxy resin adhesive, an unsaturated polyester resin adhesive, a phenolic resin adhesive, a polyacrylic resin adhesive, and a polyvinyl chloride resin adhesive, etc., which can be selected according to actual needs by those skilled in the art, and the embodiments of the present application do not limit this.

[0054] Optionally, the two electrodes 7 can be made of conductive materials, such as copper alloy and Kovar alloy, and the electrodes are used to lead out the electrodes of the piezoelectric ceramic tube.

[0055] In the embodiments of the present application, a sealing layer 10 is wrapped around the outside of the vibration sensing assembly A, and the sealing layer 10 is bonded with the connecting piece 8 to form a closed cavity, and the vibration sensing assembly A is placed in the closed cavity, thereby playing a sealing role on the vibration sensing assembly A, and making the vibration sensing assembly A isolated from seawater when used in deep sea.

[0056] In the embodiments, the sealing layer 10 has a cylindrical structure with one end open, the inner wall of the sealing layer 10 is attached to the outer side wall of the piezoelectric ceramic tube string group 1 and the side wall of the second end cover 6, and the open end of the sealing layer 10 is fixedly bonded with the outer side wall of one end of the connecting piece 8, and the end of the connecting piece 8 close to the sealing layer 10 abuts against the first end cover 5 in the vibration sensing assembly A. The connecting piece 8 is provided with a through hole along the axial direction of the ceramic tube, and the external lead wire 9 passes through the through hole of the connecting piece 8 to be electrically connected with the two electrodes 7, and the external lead wire 9 is sealingly connected with the connecting piece 8.

[0057] It should be noted that a plurality of protruding portions can be arranged at the position of the outer side wall of the connecting piece 8 bonded with the sealing layer 9, so as to increase the bonding area of the connecting piece 8 and the sealing layer 9, increase the bonding force of the connecting piece 8 and the sealing layer 9, and improve the service life of the piezoelectric detector.

[0058] Optionally, one end of the connecting piece 8 close to the piezoelectric ceramic tube string group 1 can be provided with a recess, and one end of the two electrodes 7 is placed in the recess. The outer side wall of the recess of the connecting piece is provided with an inclined surface close to one end of the piezoelectric ceramic tube string group 1, and the inclined surface of the outer side wall is engaged with the inclined surface on the first end cover, so as to increase the cooperation of the connecting piece and the first end cover, and facilitate the release of the axial force of the piezoelectric detector.

[0059] In addition, the outer wall of the connecting piece 8 is provided with a boss structure, which is connected with a corresponding interface of the ocean node device through the boss structure, so as to fix and connect the piezoelectric detector with the ocean node device.

[0060] The sealing layer 10 is used for external sealing of the piezoelectric detector, and plays a role of isolating seawater from the core vibration sensing component A of the detector through the closed cavity formed by the connecting piece 8. Optionally, the sealing layer 10 can be made of any one of epoxy resin, polyurethane, silicone rubber, fluororubber and fluorosilicone rubber. The sealing layer 10 made of the above-mentioned materials can not only play a sealing role, but also effectively transmit vibration signals, reduce the interference of the sealing layer 10 on the vibration signals, ensure that the core vibration sensing component A of the detector effectively receives the vibration signals, and improve the signal receiving sensitivity of the detector.

[0061] It should be noted that the adhesion and fixation of the sealing layer 10 and the connecting piece 8 can be adhesion and fixation by using an adhesive, or can be adhesion and fixation by directly adhesion and fixation of the connecting piece during processing of the sealing layer 10 by using the material characteristics of the sealing layer 10, for example, when the sealing layer 10 is made of epoxy resin, the connecting piece 8 is directly adhesion and fixed during the process of making the sealing layer 10 by using epoxy resin curing. The adhesion and fixation mode in the embodiment can be selected by a person skilled in the art according to the materials of the sealing layer 10 and the connecting piece 8, and details are not described herein.

[0062] In the embodiment of the present application, the deep-sea seismic node receiving piezoelectric detector adopts at least four piezoelectric ceramic round tubes to form a piezoelectric ceramic round tube string group in sequence along the axial direction, which increases the free capacitance of the detector, and the structure composed of at least four piezoelectric ceramic round tubes can better control the consistency of the sensitivity of the piezoelectric detector, thereby effectively improving the sensitivity of the piezoelectric detector. In terms of structure, the support structure is composed of the struts and the first end cover and the second end cover, which enhances the axial hydrostatic pressure resistance of the piezoelectric detector, and the middle lining and the end lining play the role of "ribs", which can enhance the radial hydrostatic pressure resistance of the cylindrical structure. Through the above design, the hydrostatic pressure resistance of the piezoelectric detector can be effectively improved, and the sensitivity of the detector can be improved, so as to ensure that the piezoelectric detector can be effectively used in deep sea.

[0063] Figure 3 A circuit connection schematic diagram of the deep-sea seismic node receiving piezoelectric detector provided by the embodiment of the present application is shown in FIG. 1. Figure 3 As shown in FIG. 1, in the case that the piezoelectric ceramic round tube string group 1 includes four piezoelectric ceramic round tubes, the four piezoelectric ceramic round tubes are radially polarized, two piezoelectric ceramic round tubes are polarized outward, and are connected in parallel through wires to form a first string group, and the other two piezoelectric ceramic round tubes are polarized inward, and are connected in parallel through wires to form a second string group, and the first string group and the second string group are connected in series through wires and connected with two electrodes 7.

[0064] In the embodiment, the piezoelectric ceramic circular tubes are radially polarized outwardly, i.e. the inner side wall of the piezoelectric ceramic circular tube is negative and the outer side wall is positive. The piezoelectric ceramic circular tubes are radially polarized inwardly, i.e. the inner side wall of the piezoelectric ceramic circular tube is positive and the outer side wall is negative.

[0065] Alternatively, two piezoelectric ceramic circular tubes close to the first end cover 5 are radially polarized outwardly, two piezoelectric ceramic circular tubes close to the second end cover 6 are radially polarized inwardly, and the outer side wall is negative. The two piezoelectric ceramic circular tubes polarized outwardly are connected in parallel by wires through the middle liner 2 to form a first string group, and the two piezoelectric ceramic circular tubes polarized inwardly are connected in parallel by wires through the middle liner 2 to form a second string group. The wires connected in parallel from the inner side of the first string group are taken out as negative electrodes and connected to the negative electrodes of the two electrodes 7, and the wires connected in parallel from the outer side of the second string group are taken out as positive electrodes and connected to the positive electrodes of the two electrodes 7.

[0066] It should be noted that in the embodiment, the polarization directions of the four piezoelectric ceramic circular tubes are the same in pairs, and the two piezoelectric ceramic circular tubes with the same polarization direction are connected in parallel by wires, and the two groups of piezoelectric ceramic circular tubes connected in parallel are connected in series by wires, and according to the above connection mode of the positive and negative electrodes, the positive electrode of the piezoelectric ceramic circular tube string group 1 is connected to the positive electrode of the two electrodes 7, and the negative electrode of the piezoelectric ceramic circular tube string group 1 is connected to the negative electrode of the two electrodes 7. In actual use, those skilled in the art can set the radial polarization directions of the four piezoelectric ceramic circular tubes according to needs and connect them by referring to the above circuit connection mode, and the embodiment of the present application will not be described again.

[0067] In the embodiment of the present application, the piezoelectric detector includes four piezoelectric ceramic circular tubes, and adjacent two piezoelectric ceramic circular tubes are arranged with the same polarization direction and connected in parallel to form two groups of piezoelectric ceramic circular tube string groups, which can effectively improve the free capacitance of the detector and improve the anti-interference ability of the detector. The two groups of piezoelectric ceramic circular tube string groups with opposite polarization directions are connected in series to the electrodes, which can effectively improve the sensitivity of the detector. By connecting in parallel and then in series, the self-capacitance of the detector can be improved, and the sensitivity of the detector can also be improved, so that the quality factor of the detector can be effectively improved. Moreover, the structure composed of four piezoelectric ceramic circular tubes can better control the consistency of the sensitivity of the detector, thereby ensuring the performance stability of the detector when used in deep sea.

[0068] It should be noted that when the number of piezoelectric ceramic circular tubes is other even numbers greater than four, the circuit connection mode of four piezoelectric ceramic circular tubes can be referred to, one half of the number of piezoelectric ceramic circular tubes is polarized outward, and is connected in parallel through wires to form a first string group; the other half of the number of piezoelectric ceramic circular tubes is polarized inward, and is connected in parallel through wires to form a second string group, the first string group and the second string group are connected in series through wires and connected with two electrodes 7. The specific circuit connection mode can refer to the above method, and will not be described here.

[0069] As Figure 4 shown, Figure 4 a deep-sea seismic node receiving piezoelectric geophone provided by the embodiment of the present application, Figure 4 is an experimental result obtained by testing the receiving sensitivity of the piezoelectric geophone under the static water pressure of 1000 meters deep sea. As can be seen from the figure, the receiving sensitivity of the piezoelectric geophone is always kept below-200dB, and is basically kept at-201dB, and the sensitivity consistency is very good, in the vibration frequency of 0-10000HZ.

[0070] The deep-sea seismic node receiving piezoelectric geophone provided by the present application is described in detail above, and the principle and implementation mode of the present application are described by applying specific examples in this paper. The above embodiment is only used to help understand the structure of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, the specific implementation mode and application range will be changed, and the above description should not be understood as a limitation of the present application.

Claims

1. A deep ocean seismic node receiving piezoelectric geophone, characterized by, The vibration sensing component, the connecting piece, the sealing layer and the external lead wire are included. The sealing layer is bonded with the connecting piece to form a closed cavity. The vibration sensing component is placed in the cavity, and the external lead wire is electrically connected with the vibration sensing component through the connecting piece. The vibration sensing component includes a piezoelectric ceramic round tube string group, a middle liner, an end liner, a support rod, a first end cover, a second end cover and two electrodes. The piezoelectric ceramic round tube string group includes at least four piezoelectric ceramic round tubes which are stacked in sequence along the axial direction, and the middle liner is arranged between adjacent two piezoelectric ceramic round tubes. The piezoelectric ceramic round tube string group is connected with the end liner at both ends. One end of the piezoelectric ceramic round tube string group is provided with the first end cover, and the other end is provided with the second end cover. The end liner separates the piezoelectric ceramic round tube string group from the first end cover and the second end cover. The support rod penetrates through the middle liner and the end liner along the axial direction of the piezoelectric ceramic round tube string group, and both ends of the support rod are fixedly connected with the first end cover and the second end cover respectively. The two electrodes are inserted into the first end cover, and the piezoelectric ceramic round tube string group is electrically connected with the two electrodes. Both sides of the middle liner and / or the end liner close to the piezoelectric ceramic round tube are provided with a limiting platform structure, and the piezoelectric ceramic round tube abuts against the limiting platform structure. When the piezoelectric ceramic round tube string group includes four piezoelectric ceramic round tubes, the four piezoelectric ceramic round tubes are radially polarized. Two piezoelectric ceramic round tubes are polarized outwardly and connected in parallel through wires to form a first string group, and the other two piezoelectric ceramic round tubes are polarized inwardly and connected in parallel through wires to form a second string group. The first string group and the second string group are connected in series through wires and connected with the two electrodes.

2. The deep ocean seismic node receiving piezoelectric geophone of claim 1, wherein, One end of the connecting piece close to the first end cover is provided with a recess, and the electrode is placed in the recess of the connecting piece.

3. The deep ocean seismic node receiving piezoelectric geophone of claim 1 wherein, The outer side wall of the recess of the connecting piece close to one end of the piezoelectric ceramic round tube string group is provided with an inclined surface, and the inclined surface of the outer side wall is matched with the inclined surface on the first end cover.

4. The deep ocean seismic node receiving piezoelectric geophone of claim 1 wherein, The first end cover and the second end cover are provided with mounting holes at positions opposite to each other close to one side of the piezoelectric ceramic round tube string group, and both ends of the support rod are fixedly connected with the mounting holes.

5. The deep ocean seismic node receiving piezoelectric geophone of claim 1 wherein, The middle liner and the end liner are made of any one of epoxy foam, rigid polyurethane foam and nano-composite foam.

6. The deep ocean seismic node receiving piezoelectric geophone of claim 5, wherein, The sealing layer is made of any one of epoxy resin, polyurethane, silicone rubber, fluororubber and fluorosilicone rubber, and is used for external sealing of the piezoelectric detector.

7. The deep ocean seismic node receiving piezoelectric geophone of claim 1 wherein, The support rod is made of metal material or high-hardness non-metal material.

8. The deep ocean seismic node receiving piezoelectric geophone of claim 1 wherein, The support rod is made of any one of stainless steel, iron, copper and pressure-resistant ceramic. The electrode is made of any one of copper alloy and Kovar alloy. The connecting piece is made of any one of hard aluminum alloy, stainless steel alloy and copper alloy.

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