Reduced-scale model experimental device of coupling responses in deep-water J-Lay operation and experimental method

Abstract

Disclosed is a reduced-scale model experimental device of coupling responses in deep-water J-lay operation, which is used for studying a coupling response characteristic of a pipeline and a pipe-layin

Description

Experimental equipment and experimental methods for coupled response tank model of deepwater J-type pipelaying operation Technical Field

[0001] The present invention belongs to the technical field of submarine pipeline laying experiments, and in particular relates to a deepwater J-shaped pipe-laying operation coupled response water tank model experimental equipment and an experimental method. Background Art

[0002] The J-lay method, a new pipelaying technology that has emerged since the 1980s, is considered the most suitable method for deepwater and ultra-deepwater pipelaying. When operating at sea, pipelay vessels are subject to the combined effects of external forces such as wind, waves, and currents, making it impossible for them to remain stationary. The vessel's horizontal and vertical motion affects the pipeline, altering its morphology and stress-strain distribution. Furthermore, because the pipeline is lowered into the deep sea at a nearly vertical angle during J-lay operations, it transitions from a nearly vertical position on the moving vessel to a horizontal position on the seabed, resulting in a large radius of curvature. The bending moment on the pipeline increases dramatically near its touchdown point. Consequently, the presence of the pipeline also affects the vessel's motion and the seabed's morphology. Therefore, studying the coupled dynamic characteristics between the pipelay vessel, pipeline, and seabed is of great theoretical and scientific significance.

[0003] Tank model experiments play an irreplaceable role because they can fully reproduce the actual operational response of structures under limited funding and site conditions and provide a basis for validation of numerical simulations. However, existing model experiments on underwater pipelines either focus on static responses, ignoring the effects of hydrodynamic forces, pipelay vessel motion, and environmental loads; or impose forced motion on the pipeline model without considering the coupling between the pipeline, the pipelay vessel, and the seabed; or create simplified pipeline models without fully considering the structural similarity between the pipeline model and the actual structure, ignoring the effects of the pipeline's bending stiffness and even axial stiffness; or sacrifice model integrity by truncating the pipeline model to improve the scale ratio. Therefore, to study the coupled response characteristics of the pipeline and pipelay vessel in deepwater J-type pipelay operations under wave loads and improve the accuracy and reliability of the experimental results, it is necessary to design a deepwater J-type pipelay operation coupled response tank model experimental equipment and methods that can fully ensure the coupling between the pipelay vessel, pipeline, and seabed model under wave loads, accurately consider the similarity between the pipeline model and the actual structure, and ensure the integrity of the experimental model.

[0004] Summary of the Invention

[0005] The purpose of the present invention is to address the technical defects of existing methods and provide a deepwater J-type pipelay operation tank model experimental equipment and experimental method. The experimental equipment and experimental method can truly and accurately reflect the coupled dynamic response characteristics of the pipelay vessel, pipeline, and seabed in deepwater J-type pipelay operations under wave loads, and accurately measure and record the tension changes at both ends of the pipeline, the movement conditions near the touchdown point, and the six-degree-of-freedom motion response of the pipelay vessel throughout the entire experimental process.

[0006] The technical solution adopted to achieve the purpose of the present invention is:

[0007] A deepwater J-type pipe-laying operation coupled response tank model experimental equipment, comprising a pipe-laying vessel model (1), a horizontal mooring mechanism, a deepwater pipeline model (17), a laying angle control mechanism, an anchor end connection mechanism, and a seabed simulation mechanism. The horizontal mooring mechanism comprises four horizontal mooring cables connected in sequence by identical thin steel wires (3), springs (4), and nylon ropes (5), four corresponding mooring cable adjustment units, and four mooring cable tension sensors (6); the thin steel wires are connected to the four corners of the side wall of the pipe-laying vessel model through the mooring cable tension sensors, and the nylon ropes are connected to the mooring cable adjustment units; the mooring cable adjustment units are installed on a slide rail (30) at the top of the side wall (31) of the tank, and can be horizontally moved or fixed along the slide rail direction, and are used to adjust the length and end position of the mooring cable, thereby adjusting the pre-tension of the mooring cable and the position and bow direction of the pipe-laying vessel model in the tank; the pipe-laying vessel model floats on the water surface (32), and the mooring cable adjustment units are connected to the side wall (31) of the tank. A six-degree-of-freedom motion sensor device (2) is installed on the surface, and the seabed simulation mechanism can be stably located on the bottom of the pool (29) under the action of gravity; the deep-water pipeline model (17) includes a polypropylene round tube and stainless steel powder inside it, and its natural form is a straight thin cylinder. After installation, its top and bottom ends are connected to the pipe-laying ship model and the seabed simulation mechanism through a laying angle control mechanism and an anchor end connection mechanism respectively. The pipeline model naturally bends under the action of gravity, and its ground contact section is flat on the seabed simulation mechanism, wherein the part near the ground contact point is marked with a yellow fluorescent sticker (18); the laying angle control mechanism is fixed to the middle longitudinal section below the pipe-laying ship model, and can adjust the angle between the top of the pipeline and the pipe-laying ship.

[0008] The mooring cable adjustment unit comprises a main body (7), a pulley (9), a brake (10) and a winch (8), wherein the pulley is in contact with a slide rail (30); the nylon rope (5) can be wound around the winch and retracted and released by rotating the winch; the brake can fix the mooring cable adjustment unit on the slide rail and fix the winch.

[0009] The deepwater pipeline model comprises several sections of polypropylene circular tubes (1701) with the same diameter and wall thickness, microspherical stainless steel powder (1702), polypropylene pipe plugs (1703) and polypropylene connecting sleeves (1704). The diameter and wall thickness of the circular tubes are determined according to the calculation results of the similarity criterion. The stainless steel powder tightly fills the interior of each section of the polypropylene circular tube. The polypropylene pipe plugs are tightly sealed at both ends of the circular tube by hot-melt and fixed to ensure the watertightness of each section of the circular tube, thereby forming several pipe sections. The pipe sections are connected by hot-melt with the connecting sleeve at the coaxial connection to form a complete pipeline model. The pipe plugs at the two ends of the pipeline model need to protrude from the cross section of the circular tube so as to match the laying angle control mechanism and the anchor end connection mechanism respectively, and facilitate disassembly and replacement.

[0010] The laying angle control mechanism includes a base (11), a rocker (13), a connecting rod (12), a push rod motor (14), a top tension sensor (15), and a pipe top sleeve (16). The base is fixed on the pipe laying ship model and fixedly connected to the push rod motor; the upper end of the rocker is hinged to the base, and the lower end is fixedly connected to the tension sensor, and a sliding groove is provided in the middle of the rocker; the connecting rod (12) is L-shaped, one end is inserted into the sliding groove of the rocker (13), and the other end is fixedly connected to the push rod of the push rod motor (14); the upper end of the pipe top sleeve (16) is coaxially fixedly connected to the tension sensor (15), and the lower end is fixedly connected to the top of the pipe model (17). The push rod motor can be remotely controlled to drive the connecting rod to perform linear motion, thereby driving the rocker to swing and driving the top of the pipe model to rotate to a specific angle.

[0011] The seabed simulation mechanism comprises a main frame (24), a bottom plate (22), a seabed model (23), a camera frame (25), an underwater high-definition binocular camera (26), a counterweight (28) and a pull rope (27). The bottom plate (22) is fixed to the bottom of the main frame (24) and contacts the bottom of the pool (29). The seabed model (23) is laid on the upper surface of the bottom plate and contacts the ground section of the pipeline model. The camera frame is installed on the main frame and can be slid along the length direction of the bottom plate to adjust its position. The underwater high-definition binocular camera is fixed on the camera frame and can be adjusted in angle and position. The counterweight includes four blocks, which are respectively fixed to the outside of the four corners of the bottom of the main frame. The pull rope has four lower ends, and the lower ends are respectively connected to the main frame.

[0012] The anchor end connection mechanism comprises a universal joint coupling (21), an underwater tension sensor (20) and a pipe bottom end sleeve (19), which are coaxially connected in series; the universal joint coupling (21) is installed at the midpoint of the end of the upper surface of the bottom plate (22) of the seabed simulation mechanism, and the pipe bottom end sleeve is coaxially fixed to the bottom end of the pipe model (17).

[0013] The experimental method of the deepwater J-type pipelay operation coupled response tank model experimental equipment according to claim 1 is characterized by comprising the following steps:

[0014] Step 1: Arrange the surface part: Move the pipe-laying vessel model into the pool and connect it to the horizontal mooring mechanism. After it stabilizes, control the four mooring cable adjustment units to gradually tighten the mooring cables until the pipe-laying vessel model moves to the specified coordinates and the mooring cable tension sensor stabilizes and reads the specified pre-tension. Calibrate the motion coordinate system of the pipe-laying vessel model using a six-degree-of-freedom motion sensing device.

[0015] Step 2: Conduct a pipelay vessel motion experiment. After the surface section is deployed and the water returns to calm, waves are generated in the tank. The six-degree-of-freedom motion of the pipelay vessel model and the changes in the tension of the four mooring cables are recorded. Pre-set groups of regular waves with different wave heights and periods, as well as irregular waves with different combinations of significant wave heights and spectral peak periods, are sequentially generated to compare the system dynamic response under different sea conditions.

[0016] Step 3: Arrange the underwater part: After completing all the experimental working conditions of the pipe-laying vessel movement, the pipeline model is connected to the pipe-laying vessel model and the seabed simulation mechanism through the laying angle control mechanism and the anchor end connection mechanism, respectively, while maintaining the position of the pipe-laying vessel model and the tension of the mooring cable unchanged. The seabed simulation mechanism is lowered to the designated position on the bottom of the pool and its posture is adjusted by pulling the rope. The laying angle at the top of the pipeline is adjusted by remote control of the laying angle control mechanism. After the system is stabilized, the readings of the tension sensors at the top and bottom of the pipeline are guaranteed to be predetermined values. During this process, the pipeline model is guaranteed not to suffer structural damage such as yielding, fracture, or plastic deformation.

[0017] Step 4: Conduct a coupled response experiment: After the underwater section is deployed and calm water is restored, begin generating waves in the pool. Record the six-degree-of-freedom motion of the pipelay vessel model, the changes in the tension of the four mooring cables, and the tension changes at the top and bottom of the pipeline model under fully coupled conditions. Use image recognition technology to capture the motion of markers near the touchdown point of the pipeline model within the underwater camera range. Generate regular and irregular waves with the same parameters as in Step 2, and compare the dynamic responses of the coupled system under different sea conditions.

[0018] Step 5: Change the laying angle of the pipe top to another preset angle through the laying angle control mechanism, and repeat step 4 to simulate the dynamic response of the coupled system under different laying angles;

[0019] Step 6: Adjust the wave direction of the pipe-laying vessel model to other preset angles through the mooring cable adjustment unit, and repeat steps 1 to 5 to simulate the system dynamic response under different wave directions.

[0020] The beneficial effects of the present invention compared with the prior art are:

[0021] (1) The mechanical similarity between the pipeline model and the real object is fully ensured, and the influence of the pipeline bending stiffness and axial stiffness on the response is fully considered, thereby improving the accuracy and credibility of the experimental results;

[0022] (2) The coupling effect between the pipe-laying vessel, pipeline, and seabed model is fully guaranteed, and the coupling dynamic response characteristics of the pipe-laying vessel, pipeline, and seabed in deepwater J-type pipe-laying operations under wave loads can be truly reflected;

[0023] (3) It can accurately and quickly adjust parameters such as the initial laying angle of the pipeline and the model's wave direction angle, improve experimental efficiency, and provide data support for actual projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG1 is a schematic structural diagram of a coupled response tank model experimental equipment for deepwater J-type pipelaying operations according to the present invention;

[0025] FIG2 is a schematic diagram of the installation of a horizontal mooring mechanism and a pipe-laying vessel model according to the present invention;

[0026] FIG3 is a schematic structural diagram of a laying angle control mechanism in the present invention;

[0027] FIG4 is a schematic structural diagram of a deepwater pipeline model according to the present invention;

[0028] FIG5 is a schematic diagram of the anchor end connection mechanism of the present invention;

[0029] FIG6 is a schematic structural diagram of a mooring cable adjustment unit according to the present invention;

[0030] FIG7 is a graph showing the temporal variation of the longitudinal sway of the pipe-laying vessel model detected by the six-degree-of-freedom motion sensing device under coupling conditions with irregular waves having a significant wave height of 0.07 m and a spectrum peak period of 2.05 s;

[0031] FIG8 is a graph showing the variation of the heave of the pipe-laying vessel model with time under the coupling condition of irregular waves with a significant wave height of 0.07 m and a spectrum peak period of 2.05 s detected by the six-degree-of-freedom motion sensing device;

[0032] FIG9 is a graph showing the variation of the top tension of the pipeline model with time, which is detected by the top tension sensor under the coupling condition of an irregular wave with a significant wave height of 0.07 m and a spectrum peak period of 2.05 s.

[0033] In the attached figure: 1- pipe-laying vessel model, 2- six-degree-of-freedom motion sensor, 3- steel wire, 4- spring, 5- nylon rope, 6- mooring cable tension sensor, 7- main body, 8- winch, 9- pulley, 10- brake, 11- base, 12- connecting rod, 13- rocker, 14- push rod motor, 15- top tension sensor, 16- pipe top sleeve, 17- deep-water pipeline model, 1701- polypropylene round tube, 1702- microspherical stainless steel powder, 1703- polypropylene olefin pipe mouth plug, 1704-polypropylene connecting sleeve, 18-marking sticker, 19-pipe bottom sleeve, 20-underwater tension sensor, 21-universal joint coupling, 22-base plate, 23-seabed model, 24-main frame, 25-camera frame, 26-underwater high-definition binocular camera, 27-pull rope, 28-counterweight, 29-pool bottom, 30-slide rail, 31-pool side wall, 32-horizontal plane, 33-trailer frame, 34-six-degree-of-freedom motion signal receiving device. DETAILED DESCRIPTION

[0034] The present invention is described in further detail below with reference to the accompanying drawings and embodiments.

[0035] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar modifications without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. In the description of the embodiments of the invention, it should be understood that the terms "connected" and "coupled" include both direct and indirect connections unless otherwise specified.

[0037] In the description of the embodiments of the invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the invention.

[0038] Example 1:

[0039] As shown in Figures 1 to 6, a coupled response tank model experimental equipment for deepwater J-type pipelaying operations includes a tank, a seabed simulation mechanism, a deepwater pipeline model 17, a horizontal mooring mechanism, a laying angle control mechanism, and an anchor end connection mechanism;

[0040] A U-shaped trailer frame 33 is installed above the pool, and two slide rails 30 are installed in parallel on both sides of the trailer frame 33. A six-degree-of-freedom motion signal receiving device 34 is installed at one end of the trailer frame 33.

[0041] A pipe-laying vessel model 1 floats on the horizontal surface 32 of the pool. A horizontal mooring mechanism positions the pipe-laying vessel model 1 at the center of the pool. A six-degree-of-freedom motion sensor 2 corresponding to a six-degree-of-freedom motion signal receiver 34 is mounted on the upper surface of the pipe-laying vessel model 1. The six-degree-of-freedom motion sensor 2 is specifically an optical signal transmitter that must be used in conjunction with the six-degree-of-freedom motion signal receiver 34 mounted on a trailer frame 33. This allows for real-time monitoring and recording of the six-degree-of-freedom motion data of the pipe-laying vessel model 1. Before the formal experiment begins, the pipe-laying vessel model 1 undergoes a free decay test and a tilt test. By placing counterweights (different from the counterweights 28 in Figure 1) inside or on the hull, the vessel's center of gravity, radius of inertia, damping coefficient, and other parameters are adjusted to match the design values.

[0042] The seabed simulation mechanism is located on the bottom of the pool. It includes a main frame 24, a bottom plate 22, a seabed model 23, a camera frame 25, an underwater high-definition binocular camera 26, a counterweight 28, and a pull rope 27.

[0043] The bottom plate 22 is a rectangular flat plate, which is surrounded and fixed by the rectangular frame at the bottom of the main frame 24. The bottom surface of the bottom plate 22 is in conflict with the bottom surface of the pool.

[0044] The seabed model 23 is laid on the upper surface of the bottom plate 22, and the seabed model 23 is in contact with the ground section of the deep-sea pipeline model;

[0045] The camera frame 25 is mounted on the main frame 24 and can slide along the length direction of the bottom plate 22;

[0046] The underwater high-definition binocular camera 26 is installed on the camera frame 25, on the crossbeam at the top of the camera frame 25, and can be adjusted in angle and position to ensure that the movement of several marked points before and after the touchdown point of the pipeline model can be captured;

[0047] There are four counterweight blocks 28 , which are respectively installed at the outer positions of the four corners of the bottom of the main frame 24 to stabilize the seabed simulation mechanism.

[0048] There are four pull ropes 27, the lower ends of which are connected to the four corners of the main frame 24 respectively, and the upper ends of which are located outside the pool and can be used to adjust the position of the seabed simulation mechanism on the bottom 29 of the pool.

[0049] A laying angle control mechanism for adjusting the angle between the top of the deep-water pipeline model 17 and the pipe-laying vessel model 1 is installed between the top of the deep-water pipeline model 17 and the pipe-laying vessel model 1. The bottom of the deep-water pipeline model 17 is connected to the seabed simulation mechanism through an anchor end connection mechanism. The deep-water pipeline model 17 naturally bends into a J shape under the action of gravity. The grounded section of the deep-water pipeline model 17 is laid flat on the seabed simulation mechanism. Yellow fluorescent stickers with a width approximately equal to the diameter of the pipeline model are installed near the touchdown point. They are wrapped around the pipeline at equal intervals as marking points to facilitate subsequent target recognition and image processing to obtain the movement of this section of the pipeline model in the experiment.

[0050] The horizontal mooring mechanism includes four sets of horizontal mooring components; the four sets of horizontal mooring components are respectively arranged at the four corners of the pipe-laying vessel model 1; each set of horizontal mooring components includes a horizontal mooring cable, a mooring cable adjustment unit and a mooring cable tension sensor 6; the four horizontal mooring cables are adjustable in length and have exactly the same properties.

[0051] Each mooring cable adjustment unit is horizontally movably mounted on a corresponding slide rail 30; when each mooring cable adjustment unit moves on the corresponding slide rail 30, the length and end position of the horizontal mooring cable change, thereby adjusting the mooring cable pretension and the wave angle of the pipe-laying vessel model 1 in the water pool.

[0052] Specifically, the horizontal mooring line is composed of a steel wire 3, a spring 4, and a nylon rope 5, connected in sequence. The geometric dimensions and mass of each component have been measured, and the stiffness of the spring 4 has been pre-measured through a tensile test. The steel wire 3 is made of thin steel wire, and one end of each steel wire 3 is connected to the four corners of the side wall of the pipe-laying vessel model 1 via a corresponding mooring cable tension sensor 6. The mooring cable tension sensor 6 is used to measure the tension applied by each horizontal mooring cable on the pipe-laying vessel model 1 in real time. The other end of each steel wire 3 is connected to one end of a corresponding spring 4, and the other end of each spring 4 is connected to one end of a corresponding nylon rope 5. The other end of each nylon rope 5 is connected to the corresponding mooring cable adjustment unit, and the nylon rope 5 has a length margin.

[0053] The anchor end connection mechanism includes a universal joint coupling 21, an underwater tension sensor 20 and a pipe bottom end sleeve 19 which are coaxially connected in series in sequence; the universal joint coupling 21 is installed at the midpoint of the end of the upper surface of the base plate 22; the underwater tension sensor 20 needs to be able to maintain watertightness and high precision for a long time at the experimental water depth, and the pipe bottom end sleeve 19 is a lightweight cylindrical component, which is coaxially fixed to the bottom end of the deep-water pipeline model 17.

[0054] The data from all the above sensors are collected synchronously in real time and processed by the data acquisition computer.

[0055] Example 2:

[0056] On the basis of the first embodiment, the present invention realizes the function of adjusting the angle between the top of the deepwater pipeline model 17 and the pipe-laying vessel model 1. The laying angle control mechanism includes a base 11, a rocker 13, a connecting rod 12, a top tension sensor 15 and a pipe top sleeve 16;

[0057] The laying angle control mechanism is installed on the lower surface of the pipe-laying vessel model 1 and the J-type pipe-laying tower (the J-type pipe-laying tower is a structure on the pipe-laying vessel. The top point of the deep-water pipeline model corresponds to the position of the J-type pipe-laying tower on the pipe-laying vessel. This structure is not shown in the schematic diagram) to simulate the function of the J-type pipe-laying tower in actual operation.

[0058] The base 11 is cylindrical, the top of the base 11 is mounted on the pipe-laying vessel model 1, and the bottom of the base 11 is mounted with a push rod motor 14;

[0059] The upper end of the rocker 13 is hinged to the side wall of the base 11, and the tension sensor 6 is installed at the lower end of the rocker 13. A strip-shaped hollow slide is provided in the middle of the rocker 13; the connecting rod 12 is L-shaped, and one end of the connecting rod 12 is movable along the length direction of the slide and is provided in the slide of the rocker 13, and the other end of the connecting rod 12 is connected to the push rod of the push rod motor 14;

[0060] The pipe top sleeve 16 is a lightweight cylindrical component. The upper end of the pipe top sleeve 16 is coaxially connected to the tension sensor 6, and the lower end of the pipe top sleeve 16 is connected to the top of the deep-water pipeline model 17. The pipe end tension sensor 6 can collect the axial tension changes at the top of the pipeline model in real time. During the actual experiment, the push rod of the push rod motor 14 can be remotely controlled to extend or retract a specified length, driving the connecting rod 12 fixed to it to perform horizontal linear motion, and the rocker 13 swings around the side wall of the base 11. The top of the pipeline model is driven to rotate to a predetermined laying angle through the tension sensor 6 and the pipe top sleeve 16, thereby adjusting the angle between the top of the deep-water pipeline model 17 and the pipe-laying vessel model 1.

[0061] Example 3:

[0062] Based on the second embodiment, the present invention realizes the function of adjusting the pre-tension of the mooring line or changing the wave angle of the pipe-laying vessel model 1 in the water tank. The mooring line adjustment unit includes a main body 7, and three pulleys 9 are installed on one side of the main body 7; the three pulleys 9 are respectively in contact with the upper surface and two side surfaces of the slide rail 30;

[0063] A brake 10 for fixing the main body 7 and a winch 8 for retracting and releasing the nylon rope 5 are respectively installed on one side of the main body 7.

[0064] The nylon rope 55 can be wound around the winch 8 and retracted and extended by rotating the winch 8; when the mooring cable adjustment unit reaches the target position on the slide rail 30, the brake 10 can be used to fix the mooring cable adjustment unit at the current position and fix the winch 8 at the same time.

[0065] A still water horizontal deflection test was performed on the connected mooring mechanism and the pipe-laying vessel model 1 to measure the horizontal stiffness of the mooring system.

[0066] Deepwater pipeline model 17 consists of a polypropylene tube 1701, tightly packed with microspherical stainless steel powder 1702. Prior to the experiment, the elastic modulus of the polypropylene material was measured through material mechanics experiments. The density of the polypropylene material and the bulk density of the stainless steel powder 1702 were also measured. The diameter and wall thickness of polypropylene tube 1701 were then determined using similarity criterion calculations. Polypropylene tube 1701 is a straight cylindrical tube; its ends are sealed with polypropylene pipe plugs 1703, which are hot-melt-sealed.

[0067] In this embodiment, the experimental water depth is shallow and the length of the pipeline model is relatively short, so there is no need to make multiple pipe sections and connect them. Only a round tube equal to the length of the pipeline model is needed, and the inside of the round tube is tightly filled with stainless steel powder 1702, and pipe mouth plugs 1703 are installed at both ends.

[0068] Example 4:

[0069] On the basis of Example 3, in order to realize the long-distance pipeline test, a polypropylene connecting sleeve 1704 is also included; there are multiple polypropylene circular tubes 1701; each polypropylene circular tube 1701 is coaxially connected, and the connection between the two polypropylene circular tubes 1701 is installed with a corresponding connecting sleeve 1704 by hot melting.

[0070] Because the pipeline model in this embodiment is over ten meters long, to facilitate filling and model making and ensure that the pipeline model used in the experiment is straight and free of plastic deformation, the polypropylene circular tube 1701 is divided into three smaller sections for transportation and storage. The sum of the lengths of the three sections equals the total length of the pipeline model. When making the deep-sea pipeline model, the interior of each section of the polypropylene circular tube 1701 is tightly filled with stainless steel powder 1702. Two polypropylene pipe plugs 1703 are then hot-melt-sealed to seal and secure the ends of the circular tube, ensuring watertightness within each section, thus forming three pipe sections. The pipe sections are coaxially connected end to end through hot-melt fusion with connecting sleeves 1704 to form a complete pipeline model. The pipe plugs 1703 at the ends of the complete pipeline model need to protrude beyond the cross-section of the circular tube to connect to the laying angle control mechanism and the anchor end connection mechanism, respectively, and to facilitate disassembly and replacement.

[0071] Due to the different scale ratios selected, according to the similarity criterion, other materials besides polypropylene can be selected to make the round tube, the tube plug 1703 and the connecting sleeve 1704. The powder can also be made of other materials besides stainless steel, such as graphite powder.

[0072] An experimental method for a coupled response tank model experimental equipment for deepwater J-type pipelaying operations includes the following steps:

[0073] Step 1: Arrange the above-water part: Move the pipe-laying vessel model 1 into the water pool and connect it to the horizontal mooring mechanism. After the pipe-laying vessel model 1 stabilizes, control the four mooring cable adjustment units to gradually tighten the horizontal mooring cables until the pipe-laying vessel model 1 moves to the specified coordinates and the mooring cable tension sensor 6 stabilizes and reads the specified pre-tension. Calibrate the motion coordinate system of the pipe-laying vessel model 1 using the six-degree-of-freedom motion sensing device 2.

[0074] Step 2: Conduct a pipelay vessel motion experiment. After the surface section is deployed and the water returns to calm, generate waves in the tank and record the six-degree-of-freedom motion of the pipelay vessel model 1 and the changes in the tension of the four horizontal mooring cables. Sequentially generate predetermined groups of regular waves with different wave height and period combinations, and irregular waves with different significant wave height and spectral peak period combinations, and compare the system dynamic response under different sea conditions.

[0075] Step 3: Arrange the underwater part: After completing all the experimental working conditions of the pipe-laying vessel movement, and under the premise of keeping the position of the pipe-laying vessel model 1 and the tension of the horizontal mooring line unchanged, connect the deep-water pipeline model 17 to the pipe-laying vessel model 1 through the laying angle control mechanism, and then connect it to the seabed simulation mechanism through the anchor end connection mechanism. Lower the seabed simulation mechanism to the specified position on the bottom surface of the water tank and adjust the posture of the seabed simulation mechanism through the pull rope 27. Adjust the laying angle of the top of the pipeline through the remote control laying angle control mechanism. Ensure that the readings of the tension sensor 15 at the top of the pipeline and the tension sensor 6 at the bottom of the pipeline are the predetermined values ​​after the system is stable. In this process, ensure that the pipeline model does not suffer structural damage such as yielding, fracture, and plastic deformation.

[0076] Step 4: Conduct a coupled response experiment: After the underwater section is deployed and calm water is restored, begin generating waves in the pool. Record the six-degree-of-freedom motion of the pipelay vessel model 1, the changes in the tension of the four horizontal mooring lines, and the tension changes at the top and bottom of the pipeline model under fully coupled conditions. Use image recognition technology to capture the motion of marked points near the touchdown point of the pipeline model within the underwater camera range. Generate regular and irregular waves with the same parameters as in Step 2, and compare the dynamic responses of the coupled system under different sea conditions.

[0077] Step 5: Change the laying angle of the pipe top to another preset angle through the laying angle control mechanism, and repeat step 4 to simulate the dynamic response of the coupled system under different laying angles;

[0078] Step 6: Adjust the wave direction of the pipe-laying vessel model 1 to other preset angles through the mooring cable adjustment unit, and repeat steps 1 to 5 to simulate the system dynamic response under different wave directions.

[0079] An example of a test:

[0080] The experimental water depth is 10 m, the scale ratio of the model to the actual object is 1:50, and the laying angle of the pipe top is 80°.

[0081] The parameters of pipe-laying vessel model 1 are as follows:

[0082] The parameters of the deepwater pipeline model 17 are as follows:

[0083] The regular wave conditions for the experiment are as follows:

[0084] The irregular wave conditions for the experiment are as follows:

[0085] The longitudinal and heaving motions of the pipe-laying vessel model and the top tension of the pipeline model measured by the pipe-laying vessel-pipeline-seabed coupled model in irregular waves with a significant wave height of 0.07 m and a spectral peak period of 2.05 s are shown in Figures 7, 8, and 9, respectively. It can be seen that there is a clear correlation between the motion of the pipe-laying vessel model and the tension of the pipeline model.

[0086] Although the embodiments disclosed herein are as described above, the contents described herein are merely embodiments for facilitating understanding of the present invention and are not intended to limit the present invention. Any person skilled in the art may make any modifications and variations in the form and details of the embodiments without departing from the spirit and scope of the present invention. However, the scope of patent protection of the present invention shall remain subject to the scope defined by the appended claims.

Claims

1. A deepwater J-type pipelaying operation coupled response tank model experimental equipment, characterized by: It includes a water tank, a seabed simulation mechanism, a deepwater pipeline model, a horizontal mooring mechanism, a laying angle control mechanism and an anchor end connection mechanism; A U-shaped trailer frame is installed above the water pool, two slide rails are installed in parallel on both sides of the trailer frame, and a six-degree-of-freedom motion signal receiving device is installed at one end of the trailer frame; a pipe-laying ship model floats on the water surface of the water pool, and a six-degree-of-freedom motion sensor device corresponding to the six-degree-of-freedom motion signal receiving device is installed on the upper surface of the pipe-laying ship model; The seabed simulation mechanism is located on the bottom surface of the pool; A laying angle control mechanism for adjusting the angle between the top of the deepwater pipeline model and the pipe-laying vessel model is installed between the top of the deepwater pipeline model and the pipe-laying vessel model, and the bottom of the deepwater pipeline model is connected to the seabed simulation mechanism through an anchor end connection mechanism; the deepwater pipeline model is naturally bent under the action of gravity, and the ground-contacting section of the deepwater pipeline model is laid flat on the seabed simulation mechanism, and a yellow fluorescent sticker for marking is installed near the ground-contacting point; The horizontal mooring mechanism comprises four groups of horizontal mooring components; the four groups of horizontal mooring components are respectively arranged at the four corners of the pipe-laying vessel model; each group of horizontal mooring components comprises a horizontal mooring cable, a mooring cable adjustment unit and a mooring cable tension sensor; each mooring cable adjustment unit is horizontally movably installed on a corresponding slide rail; when each mooring cable adjustment unit moves on the corresponding slide rail, the length and end position of the horizontal mooring cable change, thereby adjusting the pre-tension of the mooring cable and the wave angle of the pipe-laying vessel model in the water pool.

2. The deepwater J-type pipelaying operation coupled response water tank model experimental equipment according to claim 1 is characterized by: The horizontal mooring cable is composed of steel wire, spring and nylon rope connected in sequence; one end of each steel wire is connected to the four corners of the side wall of the pipe-laying vessel model through the corresponding mooring cable tension sensor; the other end of each steel wire is connected to one end of the corresponding spring; the other end of each spring is connected to one end of the corresponding nylon rope; the other end of each nylon rope is connected to the corresponding mooring cable adjustment unit.

3. The deepwater J-type pipelaying operation coupled response water tank model experimental equipment according to claim 1 is characterized by: The laying angle control mechanism includes a base, a rocker, a connecting rod, a top tension sensor and a pipe top sleeve; The top end of the base is mounted on the pipe-laying vessel model, and a push rod motor is mounted on the bottom end of the base; The upper end of the rocker is hinged to the side wall of the base, a tension sensor is installed at the lower end of the rocker, and a slide groove is arranged in the middle of the rocker; the connecting rod is L-shaped, one end of the connecting rod can be moved along the length direction of the slide groove and is arranged in the slide groove of the rocker, and the other end of the connecting rod is connected to the push rod of the push rod motor; A tension sensor is coaxially installed on the upper end of the sleeve at the top of the pipeline, and the lower end of the sleeve at the top of the pipeline is connected to the top of the deep-water pipeline model; when the push rod motor drives the connecting rod to make linear motion through the push rod, the rocker swings, driving the top of the pipeline model to rotate to a specific angle, thereby adjusting the angle between the top of the deep-water pipeline model and the pipe-laying ship model.

4. The deepwater J-type pipelaying operation coupled response tank model experimental equipment according to claim 2 is characterized by: The mooring line adjustment unit comprises a main body, and three pulleys are installed on one side of the main body; the three pulleys are respectively in contact with the upper surface and two side surfaces of the slide rail; A brake for fixing the main body and a winch for retracting and releasing the nylon rope are respectively installed on one side of the main body.

5. The deepwater J-type pipelaying operation coupled response tank model experimental equipment according to claim 1 is characterized in that : The deepwater pipeline model comprises a polypropylene round tube, the interior of which is tightly filled with micro-spherical stainless steel powder, and the polypropylene round tube is in a straight cylindrical shape; both ends of the polypropylene round tube are respectively sealed by hot-melt polypropylene pipe plugs.

6. The deepwater J-type pipelaying operation coupled response tank model experimental equipment according to claim 5 is characterized in that : Also includes a polypropylene connecting sleeve; There are multiple polypropylene round tubes; the polypropylene round tubes are coaxially connected, and the connection between two polypropylene round tubes is installed with a corresponding connecting sleeve through hot melting.

7. The deepwater J-type pipelaying operation coupled response tank model experimental equipment according to claim 1 is characterized by: The seabed simulation mechanism includes a main frame, a bottom plate, a seabed model, a camera frame, an underwater high-definition binocular camera, a counterweight and a pull rope; The bottom plate is fixed to the bottom of the main frame, and the bottom surface of the bottom plate is in conflict with the bottom surface of the pool; The seabed model is laid on the upper surface of the bottom plate, and the seabed model is in contact with the ground contact section of the deep-sea pipeline model; The camera frame is installed on the main frame and can slide along the length direction of the bottom plate; The underwater high-definition binocular camera is installed on the camera frame; There are four counterweight blocks, which are respectively installed at the outer positions of the four corners at the bottom of the main frame; There are four pull ropes, and the lower ends of the four pull ropes are respectively connected to the four corners of the main frame.

8. The deepwater J-type pipelaying operation coupled response water tank model experimental equipment according to claim 7 is characterized by: The anchor end connection mechanism comprises a universal joint coupling, an underwater tension sensor and a pipe bottom end sleeve which are coaxially connected in series in sequence; the universal joint coupling is installed at the midpoint of the end of the upper surface of the bottom plate; the pipe bottom end sleeve is coaxially fixedly connected to the bottom end of the deepwater pipe model.

9. The experimental method of the deepwater J-type pipelaying operation coupled response tank model experimental equipment according to any one of claims 1 to 8, characterized in that: The experimental method includes the following steps: Step 1: Arrange the above-water part: move the pipe-laying vessel model into the water pool and connect it to the horizontal mooring mechanism. After the pipe-laying vessel model is stable, control the four mooring cable adjustment units to gradually tighten the horizontal mooring cables until the pipe-laying vessel model moves to the specified coordinates and the mooring cable tension sensor is stable and the reading is the specified pre-tension. Calibrate the motion coordinate system of the pipe-laying vessel model through the six-degree-of-freedom motion sensor device. Step 2: Conduct the pipe-laying vessel motion experiment: after the above-water part is arranged and the still water is restored, generate waves in the pool, record the six-degree-of-freedom motion of the pipe-laying vessel model and the changes in the tension of the four horizontal mooring cables; sequentially generate preset groups of regular waves with different wave heights and period combinations and irregular waves with different significant wave heights and spectral peak period combinations, and compare the system dynamic responses under different sea conditions; Step 3: Arrange the underwater part: After completing all the experimental working conditions of the pipe-laying vessel movement, the deepwater pipeline model is connected to the pipe-laying vessel model through the laying angle control mechanism, and then connected to the seabed simulation mechanism through the anchor end connection mechanism, and the seabed simulation mechanism is lowered to the specified position on the bottom surface of the pool and the posture of the seabed simulation mechanism is adjusted by pulling the rope. The laying angle at the top of the pipeline is adjusted by remote control of the laying angle control mechanism, and the readings of the tension sensor at the top and bottom of the pipeline are guaranteed to be predetermined values ​​after the system is stable. In this process, it is ensured that the pipeline model does not suffer structural damage such as yielding, fracture, and plastic deformation; Step 4: Conduct a coupling response experiment: After the underwater part is arranged and the still water is restored, start to generate waves in the pool, record the six-degree-of-freedom motion of the pipe-laying vessel model under full coupling conditions, the changes in the tension of the four horizontal mooring cables, and the tension changes at the top and bottom of the pipeline model, and obtain the motion of the marked points near the touchdown point of the pipeline model within the underwater camera range through image recognition technology; generate regular waves and irregular waves with the same parameters as in step 2, and compare the dynamic responses of the coupling system under different sea conditions; Step 5, changing the laying angle of the top of the pipeline to other preset angles through the laying angle control mechanism, repeating step 4, and simulating the dynamic response of the coupling system under different laying angles; Step six, adjust the wave direction of the pipe-laying vessel model to other preset angles through the mooring cable adjustment unit, repeat steps one to five, and simulate the system dynamic response under different wave directions.

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