Device and method for collecting pore water under pressure maintaining condition in deep sea in-situ environment

Abstract

The invention relates to the technical field of pore water collection, and discloses a device and method for collecting pore water in a deep sea in-situ environment in a pressure maintaining mode, and the device mainly comprises a supporting frame, a negative pressure structure, a pore water extraction structure, a central control system, a driving motor, a moving motor and a sediment sampling pipe. The central control system is used for transmitting a control instruction to the driving motor and the moving motor and transmitting an operation instruction for extracting pore water to the pore water extraction structure; the sediment sampling pipe is used for collecting and storing sediment; the driving motor drives the negative pressure structure to move up and down, a pressure difference is formed in the negative pressure structure, the moving motor drives the pore water extraction structure to move left and right along an X axis and move up and down along a Y axis in the sediment sampling pipe, and the pore water extraction structure extracts the sediment on the basis of the pressure difference and in combination with two-dimensional movement of the pore water extraction structure in the sediment sampling pipe. By means of the pore water extraction device and method, the problem that only a preset horizon can be obtained in existing pore water acquisition can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of pore water collection, and in particular to a device and method for collecting pore water under pressure in a deep-sea in-situ environment. Background Art

[0002] Pore ​​water in sediments refers to the aqueous solution that occupies the pores between sediment particles on the seafloor. It is an important component of the Earth's hydrosphere, and its composition reflects the various changes between seawater and sediments. The frequent exchange of substances between pore waters in different layers contains a wealth of geochemical information, which is of great significance to the geochemical cycle of elements and the exploration of natural gas resources. Specifically, the study of organic matter and ions in pore water can become important geochemical evidence for the exploration of natural gas hydrates. At the same time, pore water in sediments can be regarded as an important indicator of sediment diagenesis and the epigenesis of sedimentary rocks, and contains important information such as diagenetic geochemical information, biological information, and the formation of natural gas hydrates. Therefore, obtaining pore water in sediments is of great research significance.

[0003] In the existing technology, the sampling methods for pore water in deep-sea sediments are mainly divided into two categories: pressure-maintained collection and non-pressure-maintained collection. The main difference between them is whether the pore water is obtained in an in-situ pressure environment. At present, most studies mainly use non-pressure-maintained methods to obtain pore water. However, seabed sediments are important research sites. If sediments are collected using non-pressure-maintained methods, the pore water obtained is very likely not the pore water of the original layer, which brings certain difficulties to deep-sea research. Although there are many devices for the collection of in-situ pore water under pressure, it still has great technical difficulties in terms of multi-sequence stratified sampling and other technologies, and the operation of existing equipment is relatively cumbersome. For example, patent document CN114674614A discloses an in-situ stratified collection device and method for pore water in seabed sediments. In the process of collecting pore water, the sampling hole on the sampling tube needs to be exactly opposite the through hole on the barrel, so that the sampling needle is opposite the sampling hole. After the sampling needle moves forward, it can pass through the through hole and the sampling hole and extend into the pore water in the sediment in the sampling tube. In addition, pore water is extracted from the sediment sample and finally flows into the negative pressure chamber until the hydrogel particles in the negative pressure chamber reach saturation and stop absorbing water, completing the pore water extraction. However, this device requires the through hole to be set in advance, and cannot change the interval between the sampling layers of pore water in real time according to the sample situation. In addition, the rate of using hydrogel particles to form negative pressure for pore water is generally slow, which greatly reduces the efficiency of operations on the seabed and cannot achieve real-time monitoring. Patent document CN114034517A discloses a hydraulically driven, high-resolution, in-situ, fidelity sampler for deep-sea sediment pore water. The sampling insert is arranged vertically, with several horizontal grooves evenly spaced across its surface, each housing a pore water sampler. However, the sampling structure can be leaky, leading to interference between samples. This requires constant manual operation of the waterstop clamp and sampling pump to extract pore water samples. Summary of the Invention

[0004] The primary purpose of the present invention is to overcome the problems existing in the prior art and provide a device for collecting pore water under pressure in a deep-sea in-situ environment. The present invention can solve the problem that the existing pore water can only be obtained from predetermined layers, and solve the problem that the current sampling equipment or process in the in-situ environment is relatively complicated.

[0005] As another object of the present invention, a method adapted to the device according to the aforementioned object is also provided.

[0006] As another object of the present invention, a non-volatile storage medium suitable for storing a computer program implemented according to the method described is provided.

[0007] To achieve the above-mentioned objectives, the present invention provides a device for collecting pore water under pressure in a deep-sea in-situ environment, comprising: a support frame, a negative pressure structure, a pore water extraction structure, a central control system, a power supply module, a sediment sampling tube, a set of rotating shafts, and a soft sampling tube, wherein one end of the soft sampling tube is connected to the negative pressure structure, and the other end is connected to the pore water extraction structure, the rotating shaft is connected to the negative pressure structure, and the signal output end of the central control system is connected to the signal input ends of the negative pressure structure and the pore water extraction structure, respectively. In which, the negative pressure structure includes a driving motor, a vacuum column, a group of sliding shafts, a piston, and a connecting rod, the output shaft of the driving motor is connected to the rotating shaft, the sliding shafts are symmetrically arranged on the outer side walls of the vacuum column, and the rotating shaft and the sliding shaft are connected by a thread, wherein the sliding shaft is an external thread and the rotating shaft is an internal thread. When the driving motor is working, the rotating shaft is driven to rotate, and the rotation of the rotating shaft drives the sliding shaft to move up and down, forming a pressure difference in the vacuum column; the piston is arranged at the top of the vacuum column, the top of the vacuum column is an opening, and the bottom is a sealing structure, the inner diameter of the opening is consistent with the outer diameter of the piston, so as to ensure that the piston can be tightly and slidably assembled in the opening, and a through hole is opened on the piston, one end of the soft sampling tube is connected to the through hole, and the other end is connected to the pore water extraction structure; the connecting rod is arranged on the piston, and the connecting rod is connected to the support frame to fix the position of the piston; The pore water extraction structure includes a mobile motor, multiple liquid containers connected in parallel, multiple valves for controlling fluid flow, a mobile shaft and a hose for transporting pore water. Both ends of each liquid container are connected to the fluid channel through the valve. Specifically, one end of some of the valves is connected to the liquid container, and the other end is connected to the soft sampling tube, which is used to apply the suction force to the liquid container; another end of the valves is connected to the liquid container, and the other end is connected to the hose, and the other end of the hose is connected to the mobile shaft. The mobile motor drives the mobile shaft to enter the sediment sampling tube, thereby enabling the pore water extraction structure to extract pore water from the sediment sampling tube and transport pore water in different layers through the hose.

[0008] Preferably, the support frame includes: a trowel plate and a sleeve. The support frame is provided with three frames, namely a first frame, a second frame and a third frame. The negative pressure structure, the central control system, the power supply module and the rotating shaft are arranged in the first frame, and the rotating shafts are respectively arranged along the vertical direction of the first frame. The pore water extraction structure is arranged in the second frame, and the sediment sampling tube is arranged in the third frame. The trowel plate is arranged at the top of the third frame, and the trowel plate is used to remove excess sediment at the bottom of the sediment sampling tube when collecting sediment; a groove is provided on the right side of the third frame, and the groove is used to limit the sediment sampling tube. A first through groove is provided on the left side of the third frame; the sleeve is provided on the top of the first frame, and the sleeve is connected to the negative pressure structure; the bottom partition in the third frame is hollow.

[0009] Preferably, the negative pressure structure also includes a vacuum gauge and a gasket. The vacuum gauge is arranged at the bottom of the vacuum column to check the vacuum degree in the vacuum column; the gasket is arranged at the bottom of the side wall of the vacuum column to prevent the piston from moving downward and damaging the vacuum gauge.

[0010] Preferably, the side wall of the piston is provided with at least one sealing ring.

[0011] Preferably, the movable axis includes an X-axis, a Y-axis and a Z-axis, the X-axis is fixedly connected to the top center position of the second frame, the Y-axis is slidably connected to the X-axis through a slide rail, and the Z-axis is slidably connected to the Y-axis through a slide rail. When the movable motor receives a start-up operation instruction from the central control system, it drives the Y-axis to move left and right on the X-axis and the Z-axis to move up and down on the Y-axis. The Z-axis is a tubular structure, one end of the Z-axis is connected to the hose, and the other end is provided with a filter head and enters and exits the sediment sampling tube; specifically, the movable motor drives the Y-axis and the Z-axis to move in a two-dimensional direction in the vertical direction, so that the Z-axis extracts pore water from different layers from the sediment sampling tube and transmits the pore water to the liquid container through the hose.

[0012] Preferably, the sediment sampling tube includes an upper cover, a tube body, and a handle. The upper cover and the tube body are connected by threads and are provided with multiple openings, which are used to drain water from the tube body; the handle is fixedly connected to the upper cover; the side wall of the tube body is provided with a second through groove in the vertical direction, and when the sediment sampling tube is fixed in the third frame, the second through groove corresponds to the first through groove, and the second through groove is sealed with a cloth-based tape, and the Z axis extracts pore water from the tube body through the cloth-based tape; the opposite side walls of the second through groove of the tube body are provided with protrusions, which match the grooves and are used to limit the sediment sampling tube.

[0013] To achieve another object of the present invention, the present invention further provides a method for collecting pore water under pressure in a deep-sea in-situ environment. The method is based on the apparatus for collecting pore water under pressure in a deep-sea in-situ environment, and the method comprises the following steps: S1: Use a sediment sampling tube to collect deep-sea sediments, and fix the sediment sampling tube in the third frame of the support frame; S2: Upon receiving a first start command from the central control system, the mobile motor drives the Z-axis of the tubular structure to the right and enters the sediment sampling tube until the Z-axis of the tubular structure pierces the cloth-based tape and enters half of the inner diameter of the sediment sampling tube, and then stops the mobile motor; S3: receiving a second start command from the central control system, starting the drive motor to rotate in the instantaneous clockwise direction, driving the vacuum column to move downward to form a pressure difference, converting the pressure difference into suction through the soft sampling tube to act on the pore water extraction structure, thereby extracting pore water from the sediment sampling tube using the Z axis of the tubular structure, until the pore water in the liquid container in the pore water extraction structure reaches half of the preset volume, and then stopping the drive motor; S4: receiving a third start instruction from the central control system to rotate the drive motor counterclockwise to eliminate the pressure difference; S5: receiving a fourth start-up instruction from the central control system, the mobile motor drives the Z-axis of the tubular structure to the left, away from the sediment sampling pipe, and completes the pore water extraction of one layer; S6: Repeat steps S2 to S5 to complete the pore water extraction of multiple layers.

[0014] Furthermore, before step S1, ultrapure water is used to clean the sediment sampling tube and the liquid container in the pore water extraction structure.

[0015] Furthermore, before fixing the sediment sampling tube in the third frame of the support frame in step S1, an underwater robot is used to align the bottom of the sediment sampling tube with the touch plate of the support frame and move from right to left to remove excess sediment at the bottom of the sediment sampling tube.

[0016] In order to achieve another object of the present invention, the present invention also provides a computer-readable storage medium having a computer program stored thereon. When the computer-stored program is executed by a processor, the method for collecting pore water under pressure in a deep-sea in-situ environment is implemented.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The present invention uses a central control system to transmit a start or stop control instruction to the driving motor and the mobile motor, and transmits an operation instruction for extracting pore water to the pore water extraction structure, wherein the output shaft of the driving motor is connected to the rotating shaft, and the rotating shaft is connected to the negative pressure structure. When the driving motor receives the start instruction, it drives the rotating shaft to rotate, thereby driving the negative pressure structure to move up and down, forming a pressure difference in the negative pressure structure. The pressure difference generates a suction effect through the soft sampling tube, and then acts on the pore water extraction structure; and the output shaft of the mobile motor is connected to the pore water extraction structure. When the mobile motor receives the start instruction, it drives the pore water extraction structure to move in the sediment. The sampling tube moves left and right along the X-axis and up and down along the Y-axis. The pore water extraction structure is based on suction and combined with the two-dimensional movement of the pore water extraction structure in the sediment sampling tube to realize the extraction of pore water from the sediment sampling tube. When the pore water extraction of one layer is completed, the driving motor and the moving motor can be controlled by the central control system to continue to extract pore water in other layers, thereby effectively solving the problem that the existing pore water acquisition can only obtain predetermined layers. In addition, the present invention is a fully automated process, and sampling can be completed without additional intervention from the operator, solving the problem that the current sampling equipment or process in the in-situ environment is relatively complicated. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a structural diagram of a device for collecting pore water under pressure in a deep-sea in-situ environment according to Example 1 of the present invention; Figure 2 This is a schematic structural diagram of a device for collecting pore water under pressure in a deep-sea in-situ environment without a vacuum column, according to Example 1 of the present invention; Figure 3 is a structural diagram of a support frame according to embodiment 1 of the present invention; Figure 4 1 is a schematic structural diagram of the connection between the valve and the liquid container according to embodiment 1 of the present invention; Figure 5 Schematic diagram of the structure of the sediment sampling tube of Example 1 of the present invention; Figure 6 1 is a schematic structural diagram of a negative pressure technology device according to embodiment 1 of the present invention; Figure 7 This is a schematic diagram of the control circuit structure of a device for collecting pore water under pressure in a deep-sea in-situ environment according to Example 1 of the present invention; Figure 8 This is a flow chart of a method for collecting pore water under pressure in a deep-sea in-situ environment according to embodiment 2 of the present invention. DETAILED DESCRIPTION

[0019] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0020] In the description of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0021] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0022] Furthermore, in the description of the present invention, unless otherwise specified, “plurality” means two or more.

[0023] Example 1 like Figure 1-7 As shown, a device for collecting pore water under pressure in a deep-sea in-situ environment, a preferred embodiment of an embodiment of the present invention, includes: a support frame 1, a negative pressure structure 2, a pore water extraction structure 3, a central control system 4, a power supply module 5, a sediment sampling tube 8, a group of rotating shafts 14 and a soft sampling tube 37, one end of the soft sampling tube 37 is connected to the negative pressure structure 2, and the other end is connected to the pore water extraction structure 3, the rotating shaft 14 is connected to the negative pressure structure 2, the signal output end of the central control system 4 is respectively connected to the signal input end of the negative pressure structure 2 and the pore water extraction structure 3, for transmitting a start or stop control instruction to the drive motor 6 and the mobile motor 7, and transmitting an operation instruction for extracting pore water to the pore water extraction structure 3; the power supply module 5 is used to supply power to the drive motor 6 and the mobile motor 7; the sediment sampling tube 8 is used to collect and store sediment.

[0024] Among them, such as Figure 6As shown, the negative pressure structure 2 includes a driving motor 6, a vacuum column 21, a group of sliding shafts 22, a piston 23, and a connecting rod 24. The output shaft of the driving motor 6 is connected to the rotating shaft 14, and the sliding shafts 22 are symmetrically arranged on the outer side walls of the vacuum column 21. The rotating shaft 14 and the sliding shaft 22 are connected by threads, wherein the sliding shaft 22 is an external thread and the rotating shaft 14 is an internal thread. When the driving motor 6 is working, it drives the rotating shaft 14 to rotate, and the rotation of the rotating shaft 14 drives the sliding shaft 22 to move up and down, forming a pressure difference in the vacuum column 21. The pressure difference generates suction through the soft sampling tube 37, and then acts on the pore water extraction structure 3; the piston 23 is arranged at the top of the vacuum column 21, the top of the vacuum column 21 is an opening, and the bottom is a sealing structure. The inner diameter of the opening It is consistent with the outer diameter of the piston 23 to ensure that the piston 23 can be tightly and slidingly assembled in the opening. Furthermore, the side wall of the piston 23 is provided with at least one sealing ring, so that the piston will not be unable to form a vacuum environment due to sealing problems during the up and down movement. A through hole is provided on the piston 23, and one end of the soft sampling tube 37 is connected to the through hole, and the other end is connected to the pore water extraction structure 3; the connecting rod 24 is provided on the piston 23, and the connecting rod 24 is connected to the support frame 1 to fix the position of the piston 23; the negative pressure structure 2 also includes a vacuum gauge 25 and a gasket 26, the vacuum gauge 25 is provided at the bottom of the vacuum column 21, and is used to check the vacuum degree in the vacuum column 21; the gasket 26 is provided at the bottom of the side wall of the vacuum column 21 to prevent the piston 23 from moving down and damaging the vacuum gauge 25.

[0025] like Figure 4As shown, the pore water extraction structure 3 includes a mobile motor 7, a plurality of liquid containers 31 connected in parallel, a plurality of valves 33 for controlling the flow of fluid, a mobile shaft 32 and a hose 38 for conveying pore water. Both ends of each of the liquid containers 31 are connected to the fluid channel through the valve 33. Specifically, one end of a portion of the valves 33 is connected to the liquid container 31, and the other end is connected to the soft sampling tube 37, which is used to apply the suction force to the liquid container 31; another end of the valves 33 is connected to the liquid container 31, and the other end is connected to the hose 38, and the other end of the hose 38 is connected to the mobile shaft 32. The output shaft of the mobile motor 7 is connected to the pore water extraction structure 3. When the mobile motor is in operation, it drives the pore water extraction structure 3 to move left and right along the X-axis and up and down along the Y-axis within the sediment sampling tube 8. Based on the suction force and combined with the two-dimensional movement of the pore water extraction structure 3 within the sediment sampling tube 8, the pore water extraction structure 3 extracts pore water from the sediment sampling tube 8. Specifically, the mobile motor 7 drives the mobile shaft 32 into the sediment sampling tube 8, thereby enabling the pore water extraction structure 3 to extract pore water from the sediment sampling tube 8 and transport it to different layers through the hose 38. It should be noted that the opening and closing of the valve 33 is controlled by a central control system, and the liquid container 31 is made of titanium alloy and mainly consists of an end cap 311 and a container 312, which are connected by threads.

[0026] Preferably, if Figure 3 As shown, the support frame 1 includes: a trowel 13, a sleeve 15, and the support frame 1 is provided with three frames 11, namely a first frame, a second frame and a third frame. The negative pressure structure 2, the central control system 4, the power supply module 5 and the rotating shaft 14 are arranged in the first frame, and the rotating shaft 14 is respectively arranged along the vertical direction of the first frame. The pore water extraction structure 3 is arranged in the second frame, and the sediment sampling tube 8 is arranged in the third frame. The trowel 13 is arranged at the top of the third frame. The trowel 13 is used to remove excess sediment at the bottom of the sediment sampling tube 8 when collecting sediment; a groove 12 is provided on the right side of the third frame, and the groove 12 is used to limit the sediment sampling tube 8. A first through groove 16 is provided on the left side of the third frame; the sleeve 15 is provided on the top of the first frame, and the sleeve 15 is connected to the negative pressure structure 2; the bottom partition in the third frame is hollow.

[0027] Preferably, the movable axis 32 includes an X-axis 321, a Y-axis 322, and a Z-axis 323. The X-axis 321 is fixedly connected to the top center of the second frame, the Y-axis 322 is slidably connected to the X-axis 321 via a slide rail, and the Z-axis 323 is slidably connected to the Y-axis 322 via a slide rail. When the movable motor 7 receives a start-up operation instruction from the central control system 4, it drives the Y-axis 322 to move left and right on the X-axis 321, and the Z-axis 323 to move up and down on the Y-axis 322. The Z-axis 323 is a tubular structure, one end of the Z-axis 323 is connected to the hose 38, and the other end is provided with a filter head and enters and exits the sediment sampling tube 8. The pore size of the filter head is 0.4um, and its main purpose is to isolate the entry of sediment and facilitate the entry of pore water; specifically, the mobile motor 7 drives the two-dimensional movement of the Y-axis 322 and the Z-axis 323 in the vertical direction, so that the Z-axis can extract pore water from different layers of the sediment sampling tube 8 and transmit the pore water to the liquid container 31 through the hose 38.

[0028] Preferably, if Figure 5 As shown, the sediment sampling tube 8 includes an upper cover 81, a tube body 82, and a handle 83. The upper cover 81 and the tube body 82 are connected by threads and are provided with multiple openings 84. The openings 84 are used to drain water from the tube body 82; the handle 83 is fixedly connected to the upper cover 81; the side wall of the tube body 82 is provided with a second through groove 85 in the vertical direction. When the sediment sampling tube 8 is fixed in the third frame, the second through groove 85 corresponds to the first through groove 16, and the second through groove 85 is sealed with a cloth-based tape. The Z axis 323 passes through the first through groove 16, the second through groove 85, and the cloth-based tape to extract pore water from the tube body 82; the opposite side walls of the second through groove 85 of the tube body 82 are provided with protrusions 86, which match the groove 12 and are used to limit the sediment sampling tube 8.

[0029] This embodiment uses a central control system to transmit start or stop control commands to the drive motor and the mobile motor, and transmits pore water extraction operation commands to the pore water extraction structure. The output shaft of the drive motor is connected to the rotating shaft, which is connected to the negative pressure structure. When the drive motor receives a start command, it drives the rotating shaft to rotate, thereby driving the negative pressure structure to move up and down, forming a pressure differential within the negative pressure structure. The pressure differential generates suction through the soft sampling tube, which in turn acts on the pore water extraction structure. The output shaft of the mobile motor is connected to the pore water extraction structure. When the mobile motor receives a start command, it drives the pore water extraction structure to move left and right along the X-axis and up and down along the Y-axis in the sediment sampling tube. The pore water extraction structure extracts pore water from the sediment sampling tube based on suction and the two-dimensional movement of the pore water extraction structure in the sediment sampling tube. When pore water extraction of one layer is completed, the drive motor and the mobile motor can be controlled by the central control system to continue extracting pore water from other layers, thereby effectively solving the problem that existing pore water extraction can only obtain pore water from a predetermined layer. Furthermore, this embodiment is a fully automated process that can complete sampling without the need for additional operator intervention, thus resolving the current problem of complex sampling equipment or processes in an in-situ environment.

[0030] Example 2 like Figure 8 As shown, a flow chart of a method for collecting pore water under pressure in a deep-sea in-situ environment according to an embodiment of the present invention is provided, wherein the method comprises: S1: Use a sediment sampling tube to collect deep-sea sediments, and fix the sediment sampling tube in the third frame of the support frame; In this embodiment, prior to S1, the sediment sampling tube 8 and liquid container 31 must be cleaned with ultrapure water. Ultrapure water contains no impurities or other chemical elements, effectively preventing these from contaminating the pore water. After cleaning, all components of the device are assembled in their designated positions, and the sidewalls of the sediment sampling tube are taped with cloth-based tape. The device operates by being mounted on an ROV (remote underwater vehicle). When the ROV reaches the designated position, the ROV manipulator removes the sediment sampling tube and vertically inserts it into the sediment. When sufficient sediment has been collected from the sediment sampling tube, the ROV manipulator removes the tube from the sediment. Because the bottom of the removed sediment sampling tube may contain excess sediment, the manipulator aligns the bottom of the tube with the touch plate of the support frame to remove any excess sediment. After removing any excess sediment from the bottom of the tube, the tube is inserted into the support frame. During insertion, the protrusions on the sidewalls of the tube must align with the grooves in the support frame. Once the sediment sampling tube is inserted into the support frame, it no longer sways left or right. At the same time, the duct tape is positioned directly in front of the pore water extraction device's "Y" and "Z" axes. Once the sediment sampling tube is in place, pore water extraction can begin.

[0031] S2: Upon receiving a first start command from the central control system, the mobile motor drives the Z-axis of the tubular structure to the right and enters the sediment sampling tube until the Z-axis of the tubular structure pierces the cloth-based tape and enters half of the inner diameter of the sediment sampling tube, and then stops the mobile motor; In this embodiment, the central system controls the movement of the motor to move the Y axis of the pore water extraction device, causing it to move horizontally to the right until the tubular structure of the Z axis pierces the cloth-based tape and penetrates the sediment. When the tubular structure reaches half the inner diameter of the sediment sampling tube, the motor is turned off.

[0032] S3: receiving a second start command from the central control system, starting the drive motor to rotate in the instantaneous clockwise direction, driving the vacuum column to move downward to form a pressure difference, converting the pressure difference into suction through the soft sampling tube to act on the pore water extraction structure, thereby extracting pore water from the sediment sampling tube using the Z axis of the tubular structure, until the pore water in the liquid container in the pore water extraction structure reaches half of the preset volume, and then stopping the drive motor; In this embodiment, the drive motor is turned on by the central control system to move the vacuum column downward. During the downward movement of the vacuum column, since the piston on the upper part of the vacuum column does not move, this process causes a vacuum to be generated in the vacuum column. Since the vacuum column is connected to the valve, liquid container and tubular structure, and since a 0.4 um filter membrane is provided at the front end of the tubular structure, this path is in a vacuum state. This process requires the drive motor to be turned on all the time in order to prevent the vacuum column from moving at its current position. Under the vacuum state, due to the existence of the pressure difference, the pore water in the sediment is quickly separated, and the pore water passes through the tubular structure, the hose and the soft pipe, and finally enters one of the liquid containers.

[0033] S4: receiving a third start instruction from the central control system to rotate the drive motor counterclockwise to eliminate the pressure difference; In this embodiment, when the volume of absorbed pore water reaches half the volume of the liquid reservoir, the central control system controls the drive motor to rotate counterclockwise. During this counterclockwise rotation, the vacuum column moves upward. When the vacuum column reaches its uppermost position, the vacuum environment is no longer present, and the drive motor is turned off.

[0034] S5: receiving a fourth start-up instruction from the central control system, the mobile motor drives the Z-axis of the tubular structure to the left, away from the sediment sampling pipe, and completes the pore water extraction of one layer; In this embodiment, the central control system activates the movement motor, causing the "Y" axis of the pore water extraction device to move horizontally to the left until the tubular structure of the "Z" axis of the pore water extraction device is free of the cloth-based tape. At this point, pore water extraction for one layer is complete.

[0035] S6: Repeat steps S2 to S5 to complete the pore water extraction of multiple layers.

[0036] If pore water from other layers needs to be sampled, the operator simply sets the corresponding layer program and repeats the above steps, moving the "Z" axis according to the layer height, as the sampling process is controlled by the central control system. Once all layer samples are collected, the equipment can be returned with the ROV, and the chemical composition of the pore water can be analyzed in the laboratory.

[0037] Example 3 An embodiment of the present invention also provides a computer storage medium on which is stored a program for a method for collecting pore water under pressure in a deep-sea in-situ environment proposed in Example 2. When the program is executed, the method for collecting pore water under pressure in a deep-sea in-situ environment is implemented.

[0038] In summary, the embodiments of the present invention provide a device, method and storage medium for collecting pore water under pressure in a deep-sea in-situ environment, which transmits a start or stop control instruction to a driving motor and a mobile motor by using a central control system, and transmits an operation instruction for extracting pore water to a pore water extraction structure, wherein the output shaft of the driving motor is connected to the rotating shaft, and the rotating shaft is connected to the negative pressure structure. When the driving motor receives the start instruction, it drives the rotating shaft to rotate, thereby driving the negative pressure structure to move up and down, forming a pressure difference in the negative pressure structure, and the pressure difference generates suction through the soft sampling tube, and then acts on the pore water extraction structure; and the output shaft of the mobile motor is connected to the pore water extraction structure, when the mobile motor receives the start instruction, it drives the rotating shaft to rotate, thereby driving the negative pressure structure to move up and down, forming a pressure difference in the negative pressure structure, and the pressure difference generates suction through the soft sampling tube, and then acts on the pore water extraction structure; and the output shaft of the mobile motor is connected to the pore water extraction structure, When the driving instruction is received, the pore water extraction structure is driven to move left and right along the X-axis and up and down along the Y-axis in the sediment sampling tube. The pore water extraction structure is based on the suction effect and combined with the two-dimensional movement of the pore water extraction structure in the sediment sampling tube to realize the extraction of pore water from the sediment sampling tube; when the pore water extraction of one layer is completed, the driving motor and the moving motor can be controlled by the central control system to continue to extract pore water in other layers, thereby effectively solving the problem that the existing pore water acquisition can only obtain predetermined layers; and the present invention is a fully automated process, which can complete sampling without additional interference from the operator, solving the problem that the sampling equipment or process in the in-situ environment is relatively complicated.

[0039] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A device for collecting pore water under pressure in a deep-sea in-situ environment, characterized in that: The device comprises: a support frame (1), a negative pressure structure (2), a pore water extraction structure (3), a central control system (4), a power supply module (5), a sediment sampling tube (8), a set of rotating shafts (14) and a soft sampling tube (37), one end of the soft sampling tube (37) is connected to the negative pressure structure (2), and the other end is connected to the pore water extraction structure (3), the rotating shaft (14) is connected to the negative pressure structure (2), and the signal output end of the central control system (4) is connected to the signal input end of the negative pressure structure (2) and the signal input end of the pore water extraction structure (3), respectively. The negative pressure structure (2) includes a driving motor (6), a vacuum column (21), a group of sliding shafts (22), a piston (23), and a connecting rod (24). The output shaft of the driving motor (6) is connected to the rotating shaft (14). The sliding shafts (22) are symmetrically arranged on the outer side walls of the vacuum column (21). The rotating shaft (14) and the sliding shaft (22) are connected by threads. The sliding shaft (22) is an external thread and the rotating shaft (14) is an internal thread. When the driving motor (6) is working, it drives the rotating shaft (14) to rotate. The rotation of the rotating shaft (14) drives the sliding shaft (22) to move up and down. A pressure difference is formed in the vacuum column (21); the piston (23) is arranged at the top of the vacuum column (21); the top of the vacuum column (21) is an opening and the bottom is a sealing structure; the inner diameter of the opening is consistent with the outer diameter of the piston (23) to ensure that the piston (23) can be tightly and slidably assembled in the opening; a through hole is opened on the piston (23); one end of the soft sampling tube (37) is connected to the through hole, and the other end is connected to the pore water extraction structure (3); the connecting rod (24) is arranged on the piston (23), and the connecting rod (24) is connected to the support frame (1) to fix the position of the piston (23); The pore water extraction structure (3) comprises a moving motor (7), a plurality of liquid containers (31) connected in parallel, a plurality of valves (33) for controlling fluid flow, a moving shaft (32) and a hose (38) for transporting pore water. Both ends of each liquid container (31) are connected to the fluid channel through the valve (33), wherein one end of a portion of the valves (33) is connected to the liquid container (31) and the other end is connected to the soft sampling tube (37), for applying the suction force to the liquid container (31); another portion of the valves (33) has one end connected to the liquid container (31) and the other end connected to the hose (38), and the other end of the hose (38) is connected to the moving shaft (32). The moving motor (7) drives the moving shaft (32) to enter the sediment sampling tube (8), thereby realizing that the pore water extraction structure (3) extracts pore water from the sediment sampling tube (8) and transports pore water of different layers through the hose (38).

2. The device for collecting pore water under pressure in a deep-sea in-situ environment according to claim 1, characterized in that: The support frame (1) comprises: a trowel plate (13), a sleeve (15), and the support frame (1) is provided with three frames (11), namely a first frame, a second frame and a third frame. The negative pressure structure (2), the central control system (4), the power supply module (5) and the rotating shaft (14) are arranged in the first frame, and the rotating shaft (14) is respectively arranged along the vertical direction of the first frame. The pore water extraction structure (3) is arranged in the second frame, and the sediment sampling tube (8) is arranged in the third frame. The squeegee (13) is arranged on the top of the third frame, and the squeegee (13) is used to remove excess sediment at the bottom of the sediment sampling tube (8) when collecting sediment; the right side of the third frame is provided with a groove (12), and the groove (12) is used to limit the sediment sampling tube (8); the left side of the third frame is provided with a first through groove (16); the sleeve (15) is arranged on the top of the first frame, and the sleeve (15) is connected to the negative pressure structure (2); the bottom partition in the third frame is hollow.

3. The device for collecting pore water under pressure in a deep-sea in-situ environment according to claim 2, characterized in that: The negative pressure structure (2) further comprises a vacuum gauge (25) and a gasket (26). The vacuum gauge (25) is arranged at the bottom of the vacuum column (21) and is used to check the vacuum degree in the vacuum column (21). The gasket (26) is arranged at the bottom of the side wall of the vacuum column (21) and is used to prevent the piston (23) from moving downward and damaging the vacuum gauge (25).

4. The device for collecting pore water under pressure in a deep-sea in-situ environment according to claim 3, characterized in that: The side wall of the piston (23) is provided with at least one sealing ring.

5. The device for collecting pore water under pressure in a deep-sea in-situ environment according to claim 2, characterized in that: The movable axis (32) includes an X-axis (321), a Y-axis (322) and a Z-axis (323), wherein the X-axis (321) is fixedly connected to the top center position of the second frame, the Y-axis (322) is slidably connected to the X-axis (321) via a slide rail, and the Z-axis (323) is slidably connected to the Y-axis (322) via a slide rail. When the movable motor (7) receives a start-up operation instruction from the central control system (4), it drives the Y-axis (322) to move left and right on the X-axis (321). The Z-axis (323) moves up and down on the Y-axis (322). The Z-axis (323) is a tubular structure. One end of the Z-axis (323) is connected to the hose (38), and the other end is provided with a filter head and enters and exits the sediment sampling tube (8). Specifically, the moving motor (7) drives the Y-axis (322) and the Z-axis (323) to move in a two-dimensional direction in the vertical direction, so that the Z-axis extracts pore water from different layers from the sediment sampling tube (8) and transmits the pore water to the liquid container (31) through the hose (38).

6. The device for collecting pore water under pressure in a deep-sea in-situ environment according to claim 5, characterized in that: The sediment sampling tube (8) comprises an upper cover (81), a tube body (82), and a handle (83). The upper cover (81) and the tube body (82) are connected by threads and provided with a plurality of openings (84). The openings (84) are used to remove water from the tube body (82). The handle (83) is fixedly connected to the upper cover (81). A second through-groove (85) is provided on the side wall of the tube body (82) in a vertical direction. When the sediment sampling tube (8) is fixed in the third frame, the second through-groove (85) corresponds to the first through-groove (16), and the second through-groove (85) is sealed with a cloth-based tape. The Z axis (323) passes through the cloth-based tape to extract pore water from the tube body (82). A protrusion (86) is provided on the opposite side wall of the second through-groove (85) of the tube body (82). The protrusion (86) matches the groove (12) and is used to limit the sediment sampling tube (8).

7. A method for collecting pore water under pressure in a deep-sea in-situ environment, the method being based on the device for collecting pore water under pressure in a deep-sea in-situ environment according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: S1: Use a sediment sampling tube to collect deep-sea sediments, and fix the sediment sampling tube in the third frame of the support frame; S2: Upon receiving a first start command from the central control system, the mobile motor drives the Z-axis of the tubular structure to the right and enters the sediment sampling tube until the Z-axis of the tubular structure pierces the cloth-based tape and enters half of the inner diameter of the sediment sampling tube, and then stops the mobile motor; S3: receiving a second start command from the central control system, starting the drive motor to rotate in the instantaneous clockwise direction, driving the vacuum column to move downward to form a pressure difference, converting the pressure difference into suction through the soft sampling tube to act on the pore water extraction structure, thereby extracting pore water from the sediment sampling tube using the Z axis of the tubular structure, until the pore water in the liquid container in the pore water extraction structure reaches half of the preset volume, and then stopping the drive motor; S4: receiving a third start instruction from the central control system to rotate the drive motor counterclockwise to eliminate the pressure difference; S5: receiving a fourth start-up instruction from the central control system, the mobile motor drives the Z-axis of the tubular structure to the left, away from the sediment sampling pipe, and completes the pore water extraction of one layer; S6: Repeat steps S2 to S5 to complete the pore water extraction of multiple layers.

8. The method for collecting pore water under pressure in a deep-sea in-situ environment according to claim 7, characterized in that: Before step S1, the sediment sampling tube and the liquid container in the pore water extraction structure are cleaned with ultrapure water.

9. The method for collecting pore water under pressure in a deep-sea in-situ environment according to claim 7, characterized in that: Before fixing the sediment sampling tube in the third frame of the support frame in step S1, an underwater robot is used to align the bottom of the sediment sampling tube with the touch plate of the support frame and move from right to left to remove excess sediment at the bottom of the sediment sampling tube.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer stored program is executed by the processor, the method for collecting pore water under pressure in a deep-sea in-situ environment as described in any one of claims 7 to 9 is implemented.

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