Time sequence deep sea seabed leakage gas trapping device and in-situ monitoring method

Abstract

The invention relates to the technical field of ocean observation equipment, in particular to a time sequence deep sea seabed leakage gas trapping device and an in-situ monitoring method.The time sequence deep sea seabed leakage gas trapping device comprises a support, an inner cavity is formed in the support by externally wrapping and connecting a floating block, and a fixed platform is connected between the floating block at the top of the inner cavity and the support in a sealed mode; a plurality of mounting ports penetrating through the rotating platform are formed in the rotating platform, inverted sampling bottles are detachably mounted at the mounting ports, electromagnetic valves are mounted at openings of the sampling bottles, a sampling port penetrating through the fixed platform is formed in the fixed platform and right below a circular track of the mounting ports, and a gas capturer is connected to the bottom surface of the fixed platform and at the sampling port; a counterweight seat which can be controlled to be separated from the support through an acoustic releaser is connected between the bottom of the inner cavity and the support, and a through opening for seabed gas to enter the inner cavity is formed in the counterweight seat. The method is low in laying and recycling requirement, small in seabed disturbance, capable of being rapidly and repeatedly laid and recycled, and capable of meeting the long-time in-situ multiple sampling requirement.

Description

Technical Field

[0001] The present invention relates to the technical field of marine observation equipment, and in particular to a time series deep seabed leakage gas capture device and an in-situ monitoring method. Background Art

[0002] Submarine gas seepage refers to the process in which gas inside the seabed is transferred upward from different sources to seawater through different forcing mechanisms such as sediment compaction, seabed overpressure caused by the dissociation of natural gas hydrates into methane gas, biogeochemical reactions, biological activities, and phase transformation. Analysis of the composition, concentration and other indicators of submarine gas seepage can indicate the source of the leaking gas, thereby reflecting the changes in the marine geochemistry and marine structural geology inside the seabed. However, it is difficult to conduct in-situ seepage gas analysis on the deep seabed, so submarine gas seepage is usually captured in situ to obtain samples, and then analyzed in the laboratory.

[0003] Seafloor gas seepage is a phenomenon driven by a variety of geological and biochemical processes, and its long-term changes are of great significance for studying seafloor geological structures and carbon cycles. The gas sampling devices in the prior art generally have the following problems: Sample contamination: Traditional permeable stone filters are easily clogged by suspended matter, resulting in a decrease in sample quality. Insufficient gas separation: The gas-liquid mixture is not treated during the sampling process, making it difficult to obtain high-purity gas samples. Lack of seepage rate measurement: Existing devices cannot achieve high-precision calculation of gas seepage rate.

[0004] At present, the disclosed seabed gas collection devices mainly include two types: active gas collection devices that penetrate into the seabed (Chinese invention patent applications CN115493897A, CN107269251B), and passive collection devices placed on the seabed surface (Chinese invention patent application CN111735671A). The former is usually used for shallow seabed gas collection. If the technology is directly transplanted to the deep sea, a complex large-scale seabed penetration mechanism is required, which will cause great disturbance to the seabed. In addition, the active gas collection of penetration will destroy the pore structure of the in-situ sediment, which may cause contamination of the collected samples and lead to large measurement errors. Passive collection devices usually use large in-situ collection devices and complete the collection through a sealable sample collection bottle. This method has little disturbance to the seabed sediment and can achieve non-destructive collection. However, the disclosed technology (Chinese invention patent application CN111735671A) requires a large underwater robot (ROV) to complete the deployment and recovery of the device. Ordinary marine research vessels cannot meet the work requirements and are costly. In addition, there is currently no technical means to achieve in-situ time series sampling of seabed gas seepage, resulting in the inability to understand the long-term changes in seabed gas seepage.

[0005] Obviously, for the complex and changeable marine environment, the above-mentioned technical methods that have been applied for disclosure still have defects and cannot meet the existing practical application needs. This is a problem that needs to be solved urgently. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention provides a time-series deep-sea seabed leakage gas capture device and an in-situ monitoring method, which can realize continuous, low-disturbance, automated gas leakage sampling in a deep-sea environment, have low deployment and recovery requirements, cause little disturbance to the seabed, can be deployed and recovered quickly and repeatedly, and meet the needs of long-term in-situ multiple sampling, aiming to improve sampling accuracy and sample purity, and realize real-time calculation of leakage rate.

[0007] The present invention is achieved through the following technical solutions: Provided is a time series deep seabed leakage gas capture device, comprising a bracket, the bracket is connected to a floating block by external wrapping to form an inner cavity for accommodating leakage gas, a fixed platform is sealedly connected to the top of the inner cavity between the floating block and the bracket, a rotating platform driven by a deep-water motor is rotatably installed on the fixed platform, a plurality of installation ports located on the same circular trajectory and penetrating the rotating platform are provided on the rotating platform, and an inverted sampling bottle is detachably installed at the installation port, an electromagnetic valve is installed at the opening of the sampling bottle, and a pressure and temperature sensor is built in the sampling bottle, a sampling port penetrating the fixed platform is provided on the fixed platform directly below the circular trajectory of the installation port, a gas capturer is connected to the bottom surface of the fixed platform at the sampling port, and an electric control valve is also installed in the sampling port at the connection with the gas capturer; the bracket is connected to a counterweight seat at the bottom of the inner cavity, which can be separated from the bracket by an acoustic releaser, and a through hole for seabed gas to enter the inner cavity is provided on the counterweight seat.

[0008] In this scheme, the main function of the floating block is to provide buoyancy for the device and ensure the stability of the device in seawater. An inner cavity for accommodating leaked gas is formed between the bracket and the floating block. The inner cavity is used to capture the gas leaking from the seabed. The top of the inner cavity is connected to the fixed platform in a sealed manner to ensure that the gas in the inner cavity will not leak, thereby effectively collecting the leaked gas. A sampling port is provided under the fixed platform. The sampling port runs through the entire fixed platform and is connected to the gas capturer. The function of the gas capturer is to extract the collected leaked gas sample from the sampling bottle to ensure the integrity of the sample and avoid any loss of gas during the collection process. The connection position between the sampling port and the gas capturer is set very accurately to ensure that the capturer can quickly and accurately capture the leaked gas after the sampling bottle is replaced. The main function of the counterweight seat is to increase the stability of the device and prevent it from shifting or tilting during long-term work on the seabed. The counterweight seat is designed with a special through port to allow the gas leaking from the seabed to enter the inner cavity, ensuring that the gas can be effectively guided into the sampling bottle during the collection process. In order to achieve remote control and automated operation, a hydroacoustic transducer is installed at the center of the rotating platform. The main function of the hydroacoustic transducer is to realize communication between the device and the surface ship, ensuring that the device can receive commands from the ship. The control cabin is located on the bottom of the fixed platform, and is equipped with a controller and a lithium battery pack for power supply. The controller is electrically connected to the deep-water motor, solenoid valve and acoustic releaser, and these components work according to the preset program through precise control instructions. In addition, the input end of the controller is electrically connected to the hydroacoustic transducer to ensure that the device can receive control instructions from the surface ship and can achieve wireless communication with the ship's control system.

[0009] Furthermore, a hydroacoustic transducer is installed at the center of the circular trajectory of the installation port of the rotating platform, and a control cabin is installed on the bottom surface of the fixed platform. A controller and a lithium battery pack for power supply are arranged in the control cabin. The output end of the controller is electrically connected to the deep-water motor, the solenoid valve and the acoustic releaser respectively, and the input end of the controller is electrically connected to the hydroacoustic transducer. The hydroacoustic transducer can communicate wirelessly with the control system of the surface vessel.

[0010] Furthermore, a groove with a radius smaller than the circular trajectory radius of the installation port is formed in the center of the surface of the fixed platform. The rotating shaft is vertically fixed in the center of the groove. The upper end of the rotating shaft is rotatably connected to the rotating platform through a bearing. A fixed gear with the center penetrated by the rotating shaft is also fixed on the rotating shaft. A driving gear meshing with the fixed gear is arranged in the groove. The deep-water motor is fixed on the bottom surface of the rotating platform and its driving shaft is connected to the center of the driving gear.

[0011] On the fixed platform, the rotating platform is installed by deep-water motor drive. Several installation ports are opened on the rotating platform. These installation ports are located on the same circular track, run through the rotating platform and have a detachable design. An inverted sampling bottle can be detachably installed at each installation port. The opening of the sampling bottle is equipped with a solenoid valve to accurately control the entry of the gas sample during sampling. The solenoid valve can automatically open and close according to the set time interval to ensure that each sampling bottle completes sample collection at the appropriate time.

[0012] Furthermore, the gas capture device includes an outer shell and a gas separation module arranged in the outer shell. The lower part of the outer shell of the gas capture device is provided with an air inlet, and the upper part is provided with an air outlet. The air inlet, the gas separation module and the air outlet together form a gas flow channel for the entry of the water-gas mixture; the gas separation module includes a separation section composed of a polymer multilayer separation membrane structure and a centrifugal impeller. The polymer multilayer separation membrane structure is arranged near the air outlet, and a multilayer membrane structure formed by polymer separation membranes with different pore sizes is arranged therein. The outer layer of the multilayer membrane structure is a large-pore membrane, and the inner layer is a small-pore membrane, and the pore size of the membrane decreases successively from the outer layer to the inner layer; the centrifugal impeller is arranged near the air inlet, and is a rotating blade driven by an electromagnetic drive device, which is used to drive the water-gas mixture into the separation section, and the separation section is used for step-by-step separation of water and gas.

[0013] The centrifugal impeller is a key mechanical component in the gas separation module. It is usually used to generate centrifugal force through rotation to help separate different components in the gas mixture. The main functions of the centrifugal impeller include: airflow acceleration and diversion: the centrifugal impeller generates centrifugal force through high-speed rotation, which causes the gas flow direction to change, usually from axial to radial, thereby accelerating the gas flow. Under the action of the centrifugal impeller, the gas will be rapidly accelerated and dispersed, thereby improving the contact efficiency between the gas and the separation medium (such as membrane, adsorbent). Particle separation: The rotation of the centrifugal impeller will generate a strong centrifugal force, so that the heavier particles (such as dust, droplets, etc.) are thrown to the outer wall, thereby achieving the separation of particles and gas. Especially in gas mixtures containing droplets or particles, the centrifugal impeller can effectively help the particles settle or aggregate, providing conditions for further gas purification. Enhance the uniformity of gas flow: Before the gas mixture enters the separation module, the centrifugal impeller can accelerate the airflow and promote the uniform flow of gas inside the module, thereby improving the overall separation efficiency.

[0014] The rotation of the centrifugal impeller is usually powered by an electromagnetic drive. The advantages of electromagnetic drive are fast response speed, high control accuracy, and the ability to accurately control the speed of the impeller by adjusting the current, thereby adjusting the speed of the airflow and the size of the centrifugal force.

[0015] The electromagnetic drive device includes the following main parts: Electromagnetic coil: The electromagnetic coil is the core part of the drive device. When powered on, it generates electromagnetic force to drive the centrifugal impeller to rotate. The magnitude and frequency of the current can control the speed of the impeller, thereby regulating the gas separation process.

[0016] Rotor and impeller connection: The centrifugal impeller is connected to the electromagnetic drive device through a rotating shaft (rotor). The electromagnetic force generated by the electromagnetic coil acts on the rotor, causing it to rotate and drive the centrifugal impeller to rotate. The rotor usually has good magnetic conductivity to facilitate the transmission of electromagnetic force.

[0017] Regulation system: The electromagnetic drive device is equipped with a regulation system that can adjust the current in real time according to different working conditions, thereby controlling the speed of the impeller and the separation efficiency. The regulation system is usually linked to the controller and the sensor to achieve automatic control.

[0018] The connection between the centrifugal impeller and the electromagnetic drive device is mainly achieved through the rotor shaft. Specifically: The role of the rotor shaft: The rotor shaft is the force transmission medium between the centrifugal impeller and the electromagnetic drive device, and it is usually located between the electromagnetic coil and the impeller. When the electromagnetic drive device generates a rotational torque through the electromagnetic coil, the rotor shaft transmits this torque to the centrifugal impeller to rotate it. The electromagnetic coil in the electromagnetic drive device is connected to the rotor shaft through a fixed bearing and support structure. The other end of the rotor shaft is fixed to the centrifugal impeller to ensure that the impeller does not fall off during rotation. The bearing system can provide smooth rotation, reduce wear and improve the stability of the system. Working principle of the electromagnetic drive device: The rotating magnetic field generated by the electromagnetic coil acts on the rotor shaft to drive it to rotate. The centrifugal impeller on the rotor shaft rotates at high speed as the shaft rotates, thereby generating centrifugal force to divert and accelerate the gas.

[0019] The electromagnetic drive device is usually located at the bottom or side of the gas separation module, close to the axis of the centrifugal impeller. The electromagnetic drive device in the figure directly drives the rotor shaft connected to it through electromagnetic force, thereby driving the rotation of the centrifugal impeller. Connection between electromagnetic drive and centrifugal impeller: The electromagnetic coil in the electromagnetic drive device is connected to the rotor shaft through magnetic force, and the rotor shaft is directly connected to the centrifugal impeller. Through the rotation of the rotor shaft, the rotational force generated by the electromagnetic drive device causes the centrifugal impeller to rotate and begins to generate centrifugal force to help gas separation.

[0020] Furthermore, a plurality of handles extending out of the floating block are connected to the circumferential side of the bracket, and each handle is provided with a gas release port, and the position of the gas release port is higher than the gas collection inlet.

[0021] There are two gas release ports on each handle to release the gas enriched at the top. The function of the gas release port is to achieve the connection between the inside and outside of the device, ensure the normal exchange of fluids, and prevent the distortion of sampling inside the device caused by excessive gas enrichment. The position of the gas release port is higher than the gas collection inlet to prevent the excessively enriched gas at the top from entering the time series gas collection port, thereby preventing the top gas from contaminating the collected gas sample. Through this design, the contamination of the gas sample is effectively reduced, ensuring the accuracy and reliability of sampling.

[0022] Furthermore, the sealed inner cavity formed by the floating block and the bracket is in a prism shape.

[0023] The prism-shaped inner cavity can facilitate gas accumulation for easy collection and capture.

[0024] Furthermore, the collecting bottle is detachably connected to the rotating platform via a spring locking buckle.

[0025] The sampling bottle is detachably connected to the rotating platform through a spring locking buckle, which is convenient for taking, placing and replacing.

[0026] Furthermore, the upper end of the bracket passes through the fixed platform to form a guardrail surrounding the rotating platform.

[0027] The bracket forms a guardrail above the fixed platform, which can protect the sampling bottles on the rotating platform and prevent collisions with the sampling bottles during diving or collection to ensure the stability of sampling.

[0028] An in-situ monitoring method using a time series deep seabed leakage gas capture device comprises the following steps: S1. Deployment: S11. Preparation before deployment: After confirming that all components in the device are working normally, the manipulator of the underwater robot ROV grabs the guardrail on the top of the device and brings the entire device to a stable deployment depth.

[0029] S12. Positioning and deployment: The ROV uses an underwater camera to determine the exact location of the seabed gas leakage and ensure that the device is directly above the leakage point. The manipulator slowly releases the device to the seabed so that the device covers the gas leakage point.

[0030] S2. Collection: S21. Activation device: After the device is deployed, it receives activation commands from surface vessels through the hydroacoustic transducer. The hydroacoustic transducer is connected to the vessel's communication system in real time to ensure accurate transmission of commands.

[0031] S22. Timed sampling: The device automatically opens the solenoid valve at a preset time interval to start the sampling process. The automatic control of the solenoid valve can ensure the accurate collection of the leaked gas mixed with seawater samples within the set time, and the collection bottle is filled with a certain amount of sample each time.

[0032] S23. Sample replacement: After completing a sample collection, the solenoid valve automatically closes to prevent more seawater from entering the sampling bottle. The deep-water motor drives the rotating platform to rotate at a preset angle so that the second sampling bottle is aligned with the sampling port and docked with the gas capturer. Each sampling bottle completes the sample exchange at the set angle.

[0033] S24, repeated sampling: complete the collection of all sample bottles in sequence, after completing the task of each sampling bottle.

[0034] S25. High-precision time control: Accurately control the time of each sampling task, keep the time interval between each sampling point consistent, and obtain accurate time series data.

[0035] S3. Recycling: S31. Triggering the recovery command: When the sampling task is completed, the surface vessel sends a release command through the hydroacoustic transducer to trigger the recovery of the device. After receiving the release command, the controller controls the acoustic releaser to activate the fuse function.

[0036] S32. Counterweight release and buoyancy: After receiving the command, the acoustic releaser is powered on and the fuse is quickly blown. The device is separated from the counterweight seat and begins to float. The controller tracks the buoyancy process of the device in real time and transmits the real-time depth and buoyancy progress to the surface ship through hydroacoustic communication.

[0037] S33, Floating and recovery: The device rises at a floating speed of 1 meter per second and floats to the surface; S34. Post-recovery operation: After recovery to the water surface, the staff can check the device, quickly replace the sampling bottle and the bottom weight, and be ready to deploy again after debugging and inspection to achieve cyclic deployment and recovery.

[0038] Furthermore, after completing each sampling task of a collection bottle, the device enters a silent state until the next collection time point ends the silent state.

[0039] The silent mode helps save power, extend the device's working time, and avoid unnecessary energy consumption. By setting the silent mode, you can save power between sampling bottles, which helps improve the device's endurance.

[0040] Furthermore, in step S2, the gas leakage rate can be measured by the sampling bottle during the sampling process. Q Perform real-time calculations to achieve long-term series observations. The formula is as follows: ; ; ; in: ΔPis the change in gas pressure, V is the effective volume of the sampling bottle, T is the ambient temperature, R is the ideal gas constant, Δ t is the sampling time interval, k filter is the multi-stage filtration membrane pass rate coefficient, k centrifge is the centrifugal separation efficiency coefficient, Q in is the gas flow rate at the centrifugal impeller inlet, Q out is the gas flow rate at the centrifugal impeller outlet, T i For the i The permeability of the first filter membrane, n is the number of filtration membrane stages.

[0041] Beneficial effects of the present invention: 1. For the first time, the in-situ time series automatic sampling of deep-sea seabed gas leakage was realized, which has the function of long-term continuous capture of seabed gas leakage and improves the ability to observe the long-term changes of leakage gas in a refined manner.

[0042] Second, the device is controlled by the seabed acoustic release device for dumping and recovery, which improves the seabed recovery speed of the device, reduces the application cost, and facilitates rapid redeployment. For the capture needs of multi-point seabed gas leakage, multiple sets of collection devices can be deployed in sequence through ROV. The device only relies on ROV for precise deployment during deployment, and does not rely on ROV for recovery. Compared with similar devices that have been disclosed, the observation cost is greatly reduced.

[0043] 3. The device is wrapped with floating material on the outside, with a small load and a small contact area with the seabed, which reduces the disturbance to the seabed gas leakage channel, avoids the potential contamination of samples by local subsidence of the seabed caused by large-load heavy sampling devices, and improves the quality of observation data of leaking gas.

[0044] Fourth, the device can be quickly redeployed by replacing modular gas capture sample bottles and bottom weights, improving the high-time-resolution capture and analysis capabilities and utilization efficiency of seabed seepage gas.

[0045] 5. The overall modular structure design of the device has fewer mechanical moving parts, high overall system stability, high gas capture reliability, and can take into account the reliability of the overall structure of the device and the efficiency of intermittent debugging for rapid and repeated use.

[0046] The design of the device of the present invention adopts a modular structure, so that various components such as sampling bottles, counterweights, batteries, etc. can be replaced and adjusted according to actual needs. This design not only improves the flexibility of the device, but also greatly simplifies the operation process, allowing users to quickly perform deployment, sampling and recovery operations in complex marine environments. The modular design ensures the efficiency and reusability of the device, greatly reducing the maintenance cost during long-term seabed monitoring.

[0047] The device is not only suitable for sampling a single gas leakage point, but also can be used to deploy multiple sets of devices in sequence through ROV to capture multiple seabed gas leakage points. Since the device does not rely on ROV recovery, the workload and cost of recovery are reduced, and it is suitable for large-scale, multi-point gas leakage capture tasks.

[0048] The present invention improves the traditional gas sampling equipment, introduces a gas separation module, a high-fidelity sampling module and an intelligent filter, and combines it with a gas leakage rate calculation algorithm, which greatly improves the sampling accuracy and data analysis capabilities of the equipment, and provides technical support for long-term monitoring and precise research of deep-sea gas leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0050] Figure 2 for Figure 1 Top view of the .

[0051] Figure 3 for Figure 1 Front view of .

[0052] Figure 4 It is a cross-sectional view of the present invention.

[0053] Figure 5 It is a schematic diagram of the bracket installation structure of the present invention.

[0054] Figure 6 for Figure 5 Top view of the .

[0055] Figure 7 It is a schematic diagram of the installation structure of the rotating platform and the fixed platform in the present invention.

[0056] Figure 8 It is a cross-sectional schematic diagram of the present invention. As shown in the figure: 1. Counterweight seat, 2. Float, 3. Handle, 4. Sampling bottle, 5. Sonar transducer, 6. Guardrail, 7. Rotating platform, 8. Control cabin, 9. Gas capture device, 10. Fixed platform, 11. Bracket, 12. Mounting port, 13. Inner cavity, 14. ROV manipulator, 15. Deepwater motor, 16. Groove, 17. Rotating shaft, 18. Fixed gear, 19. Driving gear, 20. Sampling port, 21. Air inlet, 22. Air outlet, 23. Centrifugal impeller, 24. Polymer multilayer separation membrane structure, 25. Electromagnetic drive device. DETAILED DESCRIPTION

[0057] In order to clearly illustrate the technical features of this solution, this solution is described below through a specific implementation method.

[0058] A time series deep seabed leakage gas capture device includes a bracket 11, the bracket 11 is connected to the floating block 2 by external wrapping, and an inner cavity 13 for accommodating leakage gas is formed inside the bracket 11, and the inner cavity 13 formed by the floating block 2 and the bracket 11 is prism-shaped. The bracket side is also connected to a plurality of handles extending outside the floating block in the circumferential direction, and each handle is provided with a gas release port, and the position of the gas release port is higher than the gas collection inlet, which is used to cooperate with the manipulator 14 of the ROV for deployment. The top of the inner cavity 13 is sealedly connected with a fixed platform 10 between the floating block 2 and the bracket 11, and the upper end of the bracket 11 passes through the fixed platform 10 to form a guardrail 6 arranged around the rotating platform 7. The guardrail 6 provides protection for the sample sampling bottle 4 and the hydroacoustic transducer 5, and can also be used to lift the equipment. The hydroacoustic transducer 5 is used to communicate with surface ships over long distances on the seabed, and can send information such as device status and power, and receive control commands sent by the surface ship at the same time.

[0059] A rotating platform 7 driven by a deep-water motor 15 is rotatably installed on the fixed platform 10. Specifically, a groove 16 with a radius smaller than the circular trajectory radius of the installation opening 12 is formed in the center of the surface of the fixed platform 10. A rotating shaft 17 is vertically fixed at the center of the groove 16. The upper end of the rotating shaft 17 is rotatably connected to the rotating platform 7 through a bearing. A fixed gear 18 is also fixed on the rotating shaft 17, and the center of the rotating shaft 17 passes through it. A driving gear 19 meshing with the fixed gear 18 is arranged in the groove 16. The deep-water motor 15 is fixed to the bottom surface of the rotating platform 7 and its driving shaft is connected to the center of the driving gear 19.

[0060] Among them: the deep-water motor 15 is generally a programmable underwater stepper motor, and the parameters such as the start and stop time, speed, angle, direction, etc. of the motor are set by computer software. It is a prior art, and the specific structure is not described in detail. In the present invention, the UN-NO-SE-02 programmable underwater stepper motor sold by Qingdao Lanchi Technology Co., Ltd. can be selected. It is a hydraulically compensated deceleration stepper motor with a unique closed-loop control system that can accurately feedback the output angle of the main shaft. It has a built-in clock module and related control unit, and its working state can be set through supporting software. For example, by sending a command signal, it rotates from 0 degrees to 30 degrees at a fixed speed, and then circulates every 30 minutes, which is used to change the position of the sampling bottle to facilitate the continuous collection of seabed leakage gas.

[0061] The rotating platform 7 is provided with a plurality of mounting openings 12 located on the same circular track and penetrating the rotating platform 7, and an inverted sampling bottle 4 is detachably mounted at the mounting opening 12 through a spring locking buckle, which can be replaced very conveniently and quickly. The opening of the sampling bottle 4 is equipped with a solenoid valve, and the sampling bottle 4 has a built-in pressure and temperature sensor.

[0062] In order to facilitate the control of sampling bottles 4 for sampling, each sampling bottle 4 is equidistantly distributed on a circular trajectory. According to the number of sampling bottles 4, a corresponding number of mounting ports 12 can be set, and the center angle of two adjacent sampling bottles 4 is 15°, 30°, and 60°, etc. In this embodiment, the center angle of two adjacent mounting ports 12 is 30°, and a total of 12 mounting ports are set to install 12 sampling bottles 4. After a sampling bottle 4 completes the sampling task, the deep water motor 15 controls the rotating platform to rotate 30°, so that the next sampling bottle 4 docks with the sampling port 20 to facilitate the next sampling.

[0063] After the device completes a collection task, it can be quickly put into the water again for collection by replacing the collection bottle 4 and installing the bottom counterweight seat 1, which greatly improves the use efficiency. The opening of the sampling bottle 4 is equipped with a solenoid valve, and the sampling bottle 4 is used to store the collected gas samples. The bottle body is made of heat-insulating and pressure-resistant material, which can achieve heat-insulating and pressure-maintaining sampling, and the number of sampling bottles 4 can be installed as needed. After the device completes a collection task, it can be quickly put into the water again for collection by replacing the sampling bottle 4 and installing the bottom counterweight seat 1, which greatly improves the use efficiency.

[0064] The fixed platform 10 is provided with a sampling port 20 that penetrates the fixed platform 10 just below the circular track of the mounting port 12. The bottom surface of the fixed platform 10 is connected to the gas capturer 9 at the sampling port 20, and an electric control valve is also installed inside the sampling port 20 at the connection with the gas capturer 9. The electric control valve is installed at the connection between the sampling port 20 of the sampling bottle 4 and the gas outlet of the gas capturer 9, and is connected to the gas outlet through a 316L stainless steel screw. The opening and closing degree of the electric control valve determines the size of the gas outlet, thereby controlling the sampling speed, avoiding chemical reactions of the water-gas mixture caused by volume changes, ensuring sample quality, and achieving high-fidelity sampling.

[0065] The gas capture device 9 includes an outer shell and a gas separation module arranged in the outer shell. The lower part of the outer shell of the gas capture device 9 is provided with an air inlet 21, and the upper part is provided with an air outlet 22. The air inlet 21, the gas separation module, and the air outlet 22 together form a gas flow channel for the entry of the water-gas mixture; the gas separation module includes a separation section composed of a polymer multilayer separation membrane structure 24 and a centrifugal impeller 23. The polymer multilayer separation membrane structure 24 is arranged near the air outlet 22, and a multilayer membrane structure formed by polymer separation membranes with different pore sizes is arranged therein. The outer layer of the multilayer membrane structure is a large-pore membrane, and the inner layer is a small-pore membrane, and the pore size of the membrane decreases from the outer layer to the inner layer; the centrifugal impeller 23 is arranged near the air inlet, and is a rotating blade driven by an electromagnetic drive device 25, which is used to drive the water-gas mixture into the separation section, and the separation section is used for step-by-step separation of water and gas.

[0066] The centrifugal impeller 23 generates centrifugal force by high-speed rotation, effectively accelerating the gas flow, separating the particles or droplets therein, and improving the efficiency of gas separation. The electromagnetic drive device uses electromagnetic force to drive the centrifugal impeller, and through the combination of the electromagnetic coil and the rotor shaft, the speed of the impeller is accurately controlled, thereby adjusting the speed of the airflow and the magnitude of the centrifugal force. The centrifugal impeller is connected to the electromagnetic drive device through the rotor shaft, and the electromagnetic force is transmitted to the rotor shaft to drive the centrifugal impeller to rotate.

[0067] A counterweight seat 1 is connected between the bottom of the inner cavity 13 and the bracket 11, which can be separated from the bracket 11 by an acoustic releaser controlled by an electromagnetic fuse. The counterweight seat 1 is provided with a passage for seabed gas to enter the inner cavity 13. After the bottom counterweight seat 1 is released, the device is separated from the counterweight seat 1, and the device can automatically float up. The weight of the counterweight seat 1 is calculated to ensure that the total underwater weight of the device is about 100 kg after overcoming the buoyancy of the floating block 2. After the counterweight is released, the floating block containing the floating material provides buoyancy for the device as a whole, ensuring a floating speed of about 1 m / s.

[0068] The bracket 11 is a 316L stainless steel frame structure, with a floating block 2 made of floating material wrapped on the outside, and the connection between the two is based on 316L stainless steel screws. The bottom counterweight seat 1 is a disposable structure made of cement material, with a lifting ring on the structure, which is connected to the upper collection device by a fuse, and the fuse passes through the lifting ring and is connected to the hydroacoustic releaser, which is connected to the bracket 11 with a clamp by screws. This is a mature commercial technology, and EdgeTech's hydroacoustic releaser fuse type product can be selected.

[0069] A hydroacoustic transducer 5 is installed at the center of the circular trajectory of the installation port 12 of the rotating platform 7, and a control cabin 8 is installed on the bottom surface of the fixed platform 10. A controller and a lithium battery pack for power supply are arranged in the control cabin 8. The output end of the controller is electrically connected to the deep-water motor 15, the solenoid valve and the acoustic releaser respectively, and the input end of the controller is electrically connected to the hydroacoustic transducer 5. The hydroacoustic transducer 5 can communicate wirelessly with the control system of the surface vessel.

[0070] The lithium battery pack in the control cabin 8 provides long-term power support for the device, which can ensure that the device can work for a long time without an external power supply. The battery pack and circuit design ensure that the device can continue to work at extreme depths and in harsh environments, improving the reliability and endurance of the system. A sensor is also installed at the bottom of the control cabin. The sensor is connected to the controller and power lithium battery pack inside the control cabin through a cable. The lithium battery pack is used to power the sensor, and the controller is used to control the sensor's collection start and end time, as well as the setting of the sampling frequency, etc.

[0071] The device bracket 11 and connecting parts of the present invention are all made of 316L stainless steel, which can be replaced with titanium alloy materials according to the collection requirements, thereby meeting the maximum seabed gas seepage capture requirements of 6000 m.

[0072] All key components of the device, such as the sampling bottle 4, the rotating platform 7, the deep-water motor 15, etc., are carefully designed to adapt to the harsh environment of deep sea high pressure and low temperature. The external structure and internal components of the device are made of corrosion-resistant materials, such as 316L stainless steel or titanium alloy, to ensure long-term reliable operation in the deep sea environment.

[0073] Combined with the precise control of the hydroacoustic transducer 5 and the deepwater motor 15, the device can perform adaptive sampling adjustment according to real-time data. During the sampling process, the device can automatically adjust the sampling frequency and time interval according to the type and concentration of the collected gas parameters to ensure the accuracy and representativeness of the data.

[0074] An in-situ monitoring method using a time series deep seabed leakage gas capture device comprises the following steps: S1. Deployment: S11. Preparation before deployment: After confirming that all components in the device are working normally, the manipulator of the underwater robot ROV grabs the guardrail on the top of the device and brings the entire device to a stable deployment depth.

[0075] S12. Positioning and deployment: The ROV uses an underwater camera to determine the exact location of the seabed gas leakage and ensure that the device is directly above the leakage point. The manipulator slowly releases the device to the seabed so that the device covers the gas leakage point.

[0076] S2. Collection: S21. Activating the device: After the device is deployed, it receives an activation command from a surface vessel through the hydroacoustic transducer 5. The hydroacoustic transducer 5 is connected to the communication system of the vessel in real time to ensure accurate transmission of the command.

[0077] S22, timed sampling: the device automatically opens the solenoid valve at a preset time interval to start the sampling process. The automatic control of the solenoid valve can ensure that the leakage gas mixed with seawater samples are accurately collected within the set time. The collection bottle 4 is filled with a certain amount of sample each time.

[0078] S23, sample replacement: After completing a sample collection, the solenoid valve is automatically closed to prevent more seawater from entering the sampling bottle 4. The deep-water motor 15 drives the rotating platform 7 to rotate at a preset angle so that the second sampling bottle 4 is aligned with the sampling port and docked with the gas capturer 9. Each sampling bottle 4 completes the sample exchange at the set angle.

[0079] S24, repeated sampling: complete the collection of all sample bottles 4 in sequence, and after completing the task of each sampling bottle 4; during the collection process, after completing the task of each sampling bottle 4, the device enters a silent state until the next collection time point. The silent state helps save power, extend the working time of the device, and avoid unnecessary energy consumption.

[0080] S25. High-precision time control: Accurately control the time of each sampling task, keep the time interval between each sampling point consistent, and obtain accurate time series data.

[0081] The hydroacoustic transducer 5 of the device starts working after receiving a command sent by the surface vessel. After the device starts working, the solenoid valve is automatically opened at the time interval set when the device is initially operated to collect seawater samples containing leaked gas in the inner cavity 1. After the preset collection time is reached, the solenoid valve is automatically closed, and the deep-water motor 15 drives the rotating platform 7 to rotate at a preset angle, so that the second collection bottle 4 is docked with the gas capture device 9 at the collection port, waiting for the next collection time point, and starting to repeat the above steps to complete the collection of all sample bottles in sequence.

[0082] The gas leakage rate can be measured when the sampling bottle is collecting QPerform real-time calculations to achieve long-term series observations. The formula is as follows: ; ; ; in: ΔP is the change in gas pressure, V is the effective volume of the sampling bottle, T is the ambient temperature, R is the ideal gas constant, Δ t is the sampling time interval, k filter is the multi-stage filtration membrane pass rate coefficient, k centrifge is the centrifugal separation efficiency coefficient, Q in is the gas flow rate at the centrifugal impeller inlet, Q out is the gas flow rate at the centrifugal impeller outlet, T i For the i The permeability of the first filter membrane, n is the number of filtration membrane stages.

[0083] Δ t The sampling module records the sampling start and end times through the built-in clock of the control system and calculates the time difference; ΔP The high-precision pressure sensor in the sampling bottle records the gas pressure changes before and after sampling; V uses calibration data V nominal And corrected according to the high pressure environment on the seabed: ; K is the bulk modulus of the sampling bottle material.

[0084] k centrifge The calculation is carried out by installing flow sensors at the inlet and outlet of the centrifugal module to measure Q in and Q out ; k filter The calculation is done by recording the permeability of the filter membrane step by step. T i , calculated by the total formula.

[0085] Can be used in the laboratory k centrifge Direct determination and calculation under different experimental conditions k centrifuge, draw a function curve of efficiency changing with parameters; select the parameter range closest to the field environment, and extract the corresponding efficiency value as a fixed coefficient. Reduce field complexity: There is no need to install flow sensors and measurement modules on site, reducing equipment complexity and potential failure points. Improve measurement accuracy: Accurate measurements under laboratory conditions can avoid the impact of pressure, temperature and other interferences on the data in the deep-sea environment. Reduce maintenance costs: There is no need to calibrate field sensors regularly, reducing the maintenance frequency and cost of equipment. Optimize calculation models: Laboratory measured data can be directly used to build a more stable leakage rate calculation model.

[0086] S3. Recycling: S31, triggering a recovery command: When the sampling task is completed, the surface vessel sends a release command through the hydroacoustic transducer 5 to trigger the recovery process of the device. After receiving the release command, the controller controls the acoustic releaser to activate the fuse function.

[0087] S32, counterweight release and buoyancy: After receiving the command, the acoustic releaser is powered on and the fuse is quickly blown, and the device is separated from the counterweight seat 1. The separation of the counterweight seat 1 causes the device to immediately begin to float, and the buoyancy system ensures its stable ascent. At this time, the controller tracks the buoyancy process of the device in real time, and reports the real-time depth and buoyancy progress of the device to the surface ship through hydroacoustic communication.

[0088] S33, Floating and recovery: The device automatically rises at a floating speed of about 1 meter per second and finally floats to the surface. The recovery process is completed automatically without the assistance of ROV. Through the remote communication between the hydroacoustic transducer 5 and the surface ship, the ship can prepare for the recovery operation according to the real-time position of the device, minimizing manual operation and reducing costs.

[0089] S34, post-recovery operation: After recovery to the surface, the staff can check the device, quickly replace the sampling bottle 4 and the bottom counterweight seat 1, and conduct a brief debugging and inspection. Be ready to deploy again at any time, so as to achieve rapid cycle deployment and recovery, and improve the efficiency of the submarine gas leakage collection task.

[0090] The release command is sent by the surface vessel. After the device receives the release command through the hydroacoustic transducer 5 on the seabed, the controller sends a fuse command to the acoustic releaser of the electromagnetic fuse. After the releaser is energized, the fuse is blown, and the device is separated from the counterweight and automatically floats up. The controller sends distance data in real time during the floating process until it floats to the sea surface.

[0091] After the device is recovered, the sampling bottle 4 and the bottom counterweight seat 1 can be quickly replaced and then quickly deployed again. For the capture needs of multi-point submarine gas leakage, multiple sets of collection devices can be deployed in sequence through ROV and recovered a few months later. This device only relies on ROV for precise deployment during deployment, but does not rely on ROV for recovery. Compared with similar devices that have been disclosed, this is an advantage and greatly reduces the observation cost.

[0092] Of course, the above description is not limited to the above examples. Technical features not described in the present invention can be achieved by or by using existing technologies, which will not be described here. The above embodiments and drawings are only used to illustrate the technical scheme of the present invention and are not limitations of the present invention. The present invention is described in detail with reference to the preferred implementation methods. Ordinary technicians in this field should understand that changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention do not depart from the purpose of the present invention, and should also fall within the scope of protection of the claims of the present invention.

Claims

1. A time series deep seabed leakage gas capture device, comprising a bracket, characterized in that: The bracket is connected to the floating block by external wrapping, and an inner cavity for accommodating the leaked gas is formed inside the bracket. A fixed platform is sealed and connected to the top of the inner cavity between the floating block and the bracket. A rotating platform driven by a deep-water motor is rotatably installed on the fixed platform. The rotating platform is provided with a number of installation ports located on the same circular trajectory and passing through the rotating platform, and an inverted sampling bottle is detachably installed at the installation port. A solenoid valve is installed at the opening of the sampling bottle. The sampling bottle has built-in pressure and temperature sensors. A sampling port that passes through the fixed platform is provided directly below the circular trajectory of the installation port. A gas capturer is connected to the sampling port on the bottom of the fixed platform, and an electric control valve is also installed in the sampling port at the connection with the gas capturer; the bracket is connected to a counterweight seat at the bottom of the inner cavity, which can be separated from the bracket by an acoustic releaser, and a through hole is provided on the counterweight seat for seabed gas to enter the inner cavity.

2. The time series deep seabed leakage gas capture device according to claim 1 is characterized in that: A hydroacoustic transducer is installed at the center of the circular track of the installation port of the rotating platform, and a control cabin is installed on the bottom of the fixed platform. A controller and a lithium battery pack for power supply are arranged in the control cabin. The output end of the controller is electrically connected to the deep-water motor, solenoid valve and acoustic releaser respectively, and the input end of the controller is electrically connected to the hydroacoustic transducer. The hydroacoustic transducer can communicate wirelessly with the control system of the surface vessel.

3. The time series deep seabed leakage gas capture device according to claim 1 is characterized in that: A groove with a radius smaller than the circular trajectory radius of the installation opening is formed in the center of the surface of the fixed platform. The rotating shaft is vertically fixed in the center of the groove. The upper end of the rotating shaft is rotatably connected to the rotating platform through a bearing. A fixed gear with the center penetrated by the rotating shaft is also fixed on the rotating shaft. A driving gear meshing with the fixed gear is arranged in the groove. The deep-water motor is fixed on the bottom surface of the rotating platform and its driving shaft is connected to the center of the driving gear.

4. The time series deep seabed leakage gas capture device according to claim 1 is characterized in that: The gas capture device includes an outer shell and a gas separation module arranged in the outer shell. The lower part of the outer shell of the gas capture device is provided with an air inlet, and the upper part is provided with an air outlet. The air inlet, the gas separation module and the air outlet together form a gas flow channel for the entry of the water-gas mixture. The gas separation module includes a separation section composed of a polymer multilayer separation membrane structure and a centrifugal impeller. The polymer multilayer separation membrane structure is arranged near the air outlet, and a multilayer membrane structure formed by polymer separation membranes with different pore sizes is arranged therein. The outer layer of the multilayer membrane structure is a large-pore membrane, and the inner layer is a small-pore membrane, and the pore size of the membrane decreases successively from the outer layer to the inner layer. The centrifugal impeller is arranged near the air inlet, and is a rotating blade driven by an electromagnetic drive device, which is used to drive the water-gas mixture into the separation section, and the separation section is used for step-by-step separation of water and gas.

5. The time series deep seabed leakage gas capture device according to claim 1 is characterized in that: The side of the bracket is also connected to a plurality of handles extending out of the floating block in the circumferential direction, and each handle is provided with a gas release port, and the position of the gas release port is higher than the gas collection inlet.

6. The time series deep seabed leakage gas capture device according to claim 1 is characterized by: The collecting bottle is detachably connected to the rotating platform through a spring locking buckle.

7. The time series deep seabed leakage gas capture device according to claim 1 is characterized by: The upper end of the bracket passes through the fixed platform to form a guardrail surrounding the rotating platform.

8. An in-situ monitoring method using the time series deep seabed leakage gas capture device of claim 1, characterized in that: The following steps are involved: S1. Deployment: S11. Preparation before deployment: After confirming that all components in the device are working normally, the manipulator of the underwater robot ROV grabs the guardrail on the top of the device and brings the entire device to a stable deployment depth; S12, Positioning and deployment: The ROV uses an underwater camera to determine the exact location of the seabed gas leakage, ensuring that the device is directly above the leakage point. The manipulator slowly releases the device to the seabed so that the device covers the gas leakage point. S2. Collection: S21. Activation device: After the device is deployed, it receives the activation command from the surface ship through the hydroacoustic transducer. The hydroacoustic transducer is connected with the ship's communication system in real time to ensure accurate transmission of the command; S22, timed sampling: the device automatically opens the solenoid valve at a preset time interval to start the sampling process. The automatic control of the solenoid valve can ensure that the leakage gas mixed with seawater samples are accurately collected within the set time, and the collection bottle is filled with a certain amount of sample each time; S23, sample replacement: After completing a sample collection, the solenoid valve automatically closes to prevent more seawater from entering the sampling bottle. The deepwater motor drives the rotating platform to rotate at a preset angle so that the second sampling bottle is aligned with the sampling port and docked with the gas capturer. Each sampling bottle completes the sample exchange at the set angle; S24, repeated sampling: completing the collection of all sample bottles in sequence, after completing the task of each sampling bottle; S25, high-precision time control: accurately control the time of each sampling task, the time interval between each sampling point is consistent, and accurate time series data is obtained; S3. Recycling: S31, triggering a recovery command: when the sampling task is completed, the surface vessel sends a release command through the hydroacoustic transducer to trigger the recovery of the device. After receiving the release command, the controller controls the acoustic releaser to activate the fuse function; S32, counterweight release and buoyancy: After receiving the command, the acoustic releaser is powered on and the fuse is quickly blown, the device is separated from the counterweight seat, and the device begins to float. The controller tracks the buoyancy process of the device in real time and transmits the real-time depth and buoyancy progress to the surface ship through hydroacoustic communication; S33, Floating and recovery: The device rises at a floating speed of 1 meter per second and floats to the surface; S34. Post-recovery operation: After recovery to the water surface, the staff can check the device, quickly replace the sampling bottle and the bottom weight, and be ready to deploy again after debugging and inspection to achieve cyclic deployment and recovery.

9. The in-situ monitoring method according to claim 8, characterized in that: After completing each sampling task of the collection bottle, the device enters the silent state until the next collection time point ends the silent state.

10. The in-situ monitoring method according to claim 8, characterized in that: In step S2, the gas leakage rate can be measured by the sampling bottle during sampling. Q Perform real-time calculations to achieve long-term series observations. The formula is as follows: ； ； ； in: ΔP is the change in gas pressure, V is the effective volume of the sampling bottle, T is the ambient temperature, R is the ideal gas constant, Δ t is the sampling time interval, k filter is the multi-stage filtration membrane pass rate coefficient, k centrifge is the centrifugal separation efficiency coefficient, Q in is the gas flow rate at the centrifugal impeller inlet, Q out is the gas flow rate at the centrifugal impeller outlet, T i For the i The permeability of the first filter membrane, n is the number of filtration membrane stages.

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