Active marine riser vortex-induced vibration suppression device based on vibration reduction fins

Abstract

In order to solve the problems that an existing vortex-induced vibration suppression device is complex in structure, inconvenient to disassemble and assemble, not convenient to maintain, large in energy consumption and the like, the active marine riser vortex-induced vibration suppression device comprises a pipe sleeve and a plurality of vibration reduction assemblies, the pipe sleeve is arranged on a riser in a sleeving mode and detachably connected with the riser, and the vibration reduction fins are arranged on the pipe sleeve. The multiple damping assemblies are evenly distributed on the periphery of the pipe sleeve in the circumferential direction, the pipe sleeve comprises two semicircular pipe sleeves, and the two semicircular pipe sleeves are clamped on the outer wall of the vertical pipe through fixing pieces. According to the invention, the energy consumption is relatively low, the dependence degree on the vertical pipe device is relatively small, the complexity of the system is not additionally increased, through the design of the two semicircular pipe sleeves, the pipe sleeves can be quickly mounted and dismounted, and the pipe sleeves can be used while being mounted, are convenient to mount and easy to maintain, also have relatively wide applicability, and are suitable for popularization and application. And the vibration suppression device has high adaptability to the vibration suppression problem of different engineering equipment. The invention relates to the technical field of vortex-induced vibration suppression.

Description

Technical Field

[0001] The present invention relates to the technical field of vortex-induced vibration suppression, and in particular to an active marine riser vortex-induced vibration suppression device based on vibration-damping fins. Background Art

[0002] Vortex-induced vibration (VIV) is a common phenomenon of structural vibration under the action of fluid, which is widely found in the fields of marine engineering, aerospace and bridge construction. With the expansion of engineering scale and the increase of complex environmental conditions, VIV poses a severe challenge to the safety and stability of structures. Therefore, it is particularly important to develop efficient active vibration suppression devices. Currently, the commonly used VIV suppression devices are mainly divided into the following categories: 1. Absorbing vibration energy by adding passive devices such as dampers, but this method is usually unable to cope with complex multi-frequency excitation situations; 2. Using shape optimization and other means to change the flow field distribution on the surface of the structure to weaken VIV, but this method has the problems of long design cycle and high cost; 3. Active vibration suppression devices based on electromagnetic, hydraulic or piezoelectric principles can achieve higher control accuracy, but most of the existing devices have problems such as high energy consumption, slow response speed and complex installation and maintenance.

[0003] There are many ways to actively suppress vortex-induced vibration, but there are few studies on active vibration suppression devices with a wide range of applications, easy use, ready to install and easy to maintain. The existing active vortex-induced vibration structure design is complex, energy-intensive, and highly dependent on the riser device itself. The structure mostly uses a sleeve installed outside the riser, and a rotating part is set on the sleeve, which is inconvenient to install and disassemble, and when rotating, there will be additional resistance. For example, Publication No.: CN111306148 B is a marine riser vortex-induced vibration suppression device.

[0004] Therefore, developing an active marine riser vortex-induced vibration suppression device that is efficient, low-energy-consuming and easy to maintain is still a difficult problem that needs to be solved urgently in the current engineering field. Summary of the invention

[0005] The present invention aims to solve the problems of the existing vortex-induced vibration suppression device, such as complex structure, inconvenient assembly and disassembly, difficult maintenance and high energy consumption, and further proposes an active marine riser vortex-induced vibration suppression device based on vibration-damping fins.

[0006] The technical solution adopted by the present invention to solve the above problems is:

[0007] The present invention comprises a pipe sleeve and a plurality of vibration reduction components. The pipe sleeve is sleeved on a vertical pipe and is detachably connected to the vertical pipe. The plurality of vibration reduction components are evenly distributed on the outer circumference of the pipe sleeve along the circumferential direction. The pipe sleeve comprises two semicircular pipe sleeves, which are clamped on the outer wall of the vertical pipe by fixing parts.

[0008] Furthermore, each of the vibration damping components includes a vibration damping fin, a bearing, a fixed rotating shaft, two first connecting parts, a servo motor and a second connecting part. The two first connecting parts are vertically and relatively arranged. The lower end of each first connecting part is fixedly connected to the outer wall of the pipe sleeve, and the upper end is rotatably connected to the side wall of the vibration damping fin; the bearing, the fixed rotating shaft, the servo motor and the second connecting part are all located in the vibration damping fin, and a servo motor is respectively installed at both ends of the second connecting part, and the output end of the servo motor is fixedly connected to one end of the fixed rotating shaft, and the other end of the fixed rotating shaft is connected to the inner side of the upper end of the first connecting part through a bearing.

[0009] Furthermore, the bearing is installed at the junction of the vibration-damping fin and the first connecting member, the outer diameter of the bearing is the same as the size of the side wall opening of the vibration-damping fin, and the inner diameter of the bearing is the same as the diameter of the fixed shaft.

[0010] Furthermore, the second connecting member is a circular tube, and the second connecting member is connected to the servo motors at both ends as a whole.

[0011] Furthermore, two connecting ends of each semicircular pipe sleeve are respectively provided with connecting ear plates.

[0012] Furthermore, a sensor and an embedded PID are arranged on the inner wall of the pipe sleeve.

[0013] The beneficial effects of the present invention are:

[0014] 1. The present invention has low energy consumption and low dependence on the riser device itself, and will not increase the complexity of the system. Through the design of two semicircular pipe sleeves, the pipe sleeves can be quickly installed and disassembled, so that it can be installed and used immediately, and is easy to install and maintain. It also has a wide range of applicability and is highly adaptable to the vibration suppression problems of different engineering equipment;

[0015] 2. The present invention realizes connection between the servo motor body and the inner wall of the vibration-damping fin through the second connecting member, thereby transmitting the control movement of the servo motor and realizing the rotation movement of the vibration-damping fin around the fixed rotating shaft; the vibration-damping fins installed around the pipe sleeve can be aligned with the flow in different directions in the plane, and then realize the optimal angle of attack state respectively, without causing additional resistance;

[0016] 3. The present invention provides a bearing at the connection between the vibration-damping fin and the first connecting member, which can not only ensure the water tightness of the device, but also avoid the fixed shaft and the vibration-damping fin being directly connected to hinder the rotation of the vibration-damping fin itself;

[0017] 4. The vibration suppression effect of the present invention has been verified by relevant numerical simulations, and after obtaining a large amount of training data, by combining the PID control method, real-time rotation control of the vibration-damping fins can be performed on the monitored riser movement to achieve the best vibration suppression effect without causing additional resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0019] Figure 2 is a structural schematic diagram of the vibration-damping fin structure;

[0020] Figure 3 yes Figure 2 A partial enlarged view of

[0021] Figure 4 It is a schematic diagram of the composition of the casing;

[0022] Figure 5 It is a schematic diagram of the assembly of the present invention and the riser;

[0023] Figure 6 is the rotatability of the vibration-damping fin;

[0024] Figure 7 It is a schematic diagram of the numerical model of the present invention;

[0025] Figure 8 Comparison of the vibration suppression effects of the numerical model under different working conditions. DETAILED DESCRIPTION

[0026] The active marine riser vortex-induced vibration suppression device based on vibration-damping fins described in this embodiment is as follows: Figure 1 As shown, it includes a pipe sleeve 7 and a plurality of vibration reduction components, and the plurality of vibration reduction components are evenly distributed and installed on the outer periphery of the pipe sleeve 7 along the circumferential direction. The pipe sleeve 7 includes two semicircular pipe sleeves 10, as shown in FIG. Figure 4 As shown, two semicircular pipe sleeves 10 are detachably connected to the vertical pipe 8 through a fixing piece. Connecting ear plates 9 are respectively provided at both ends of each semicircular pipe sleeve 10, and bolts are passed through the connecting ear plates 9 of the two semicircular pipe sleeves 10 in sequence and then fixed with nuts to clamp the two semicircular pipe sleeves 10 on the vertical pipe 8.

[0027] like Figure 2 , Figure 3 As shown, each of the vibration damping components includes a vibration damping fin 1, a bearing 2, a fixed rotating shaft 3, two first connecting members 4, a servo motor 5 and a second connecting member 6. The two first connecting members 4 are vertically and relatively arranged. The first connecting member 4 is two connecting rods with a certain length, the lower ends of which are welded and fixed to the outer wall of the pipe sleeve 7, and the upper ends are rotatably connected to the vibration damping fins through the fixed rotating shaft 3 and the bearing 2; the bearing 2, the fixed rotating shaft 3, the servo motor 5 and the second connecting member 6 are all located in the vibration damping fin 1, the second connecting member 6 is fixedly connected to the vibration damping fin 1, and a servo motor 5 is respectively provided at both ends of the second connecting member 6, the output end of the servo motor 5 is fixedly connected to one end of the fixed rotating shaft 3, and the other end of the fixed rotating shaft 3 is connected to the inner side of the upper end of the first connecting member 4 through the bearing 2.

[0028] Preferably, the servo motor 5 body is connected to a second connecting member 6, which is connected to the vibration-damping fin 1 through the second connecting member 6, thereby transmitting the control movement of the servo motor 5 and realizing the rotational movement of the vibration-damping fin 1 around the fixed rotating axis. The surrounding anti-roll fins can be aligned with the flow in different directions in the plane, and then respectively achieve the best angle of attack state to adapt to the state without causing additional resistance.

[0029] The fixed shaft 3 and the motor shaft of the servo motor 5, the second connecting member 6 and the inner wall of the vibration-damping fin 1, and the bearing 2 and the side wall 1 of the vibration-damping fin are all connected by interference fit between the shaft diameters, and the installation operation is highly convenient.

[0030] Preferably, the second connecting member 6 is a circular tube, which is designed as an integral body with the body of the servo motor 5 at both ends, and the lower end of the fixed shaft 3 is provided with an aperture of a size matching the motor shaft of the servo motor 5, so that the two can be tightly connected, ensuring that the motor shaft remains static when the servo motor is working, while the body is in a rotational dynamic state relative to the fixed shaft 3 and the motor shaft under the control signal of the servo motor;

[0031] Preferably, considering the water tightness of the device and the fact that the fixed shaft 3 and the vibration-damping fin 1 cannot be directly connected to avoid hindering the rotation of the vibration-damping fin itself, a bearing 2 is arranged at the connection between the vibration-damping fin 1 and the first connecting member 4, and the outer diameter of the bearing 2 is the same as the size of the opening of the vibration-damping fin 1, and the inner diameter is the same as the diameter of the fixed shaft 3.

[0032] Preferably, a sensor and an embedded PID are provided on the inner wall of the pipe sleeve 7. The sensor and the embedded PID can monitor the vibration state of the riser in real time, realize the monitoring of the riser motion related data and the calculation of the control signal and output it to the servo motor 5 system, and then respectively control the rotation of the vibration reduction fins 1 around the pipe sleeve 7 to change the vortex shedding mode, reduce the lift resistance of the riser, achieve the effect of suppressing vibration, and will not bring additional resistance.

[0033] Working principle:

[0034] In the present invention, when the incoming flow acts on the riser 8, the riser 8 generates vortex-induced vibration, and the half-pipe sleeve 10 is connected to the riser 8 by bolts, which then generates vibration. Sensors and embedded PID are arranged inside the pipe sleeve 7. These sensors can measure the movement of the riser 8, including the acceleration, speed and displacement of the riser 8. By analyzing these data, the vibration state of the riser is monitored in real time, and the servo motor 5 system can be quickly controlled in combination with the embedded PID. The vortex shedding mode is changed by rotating the vibration-damping fins 1 around the pipe sleeve 7, and the lift resistance of the riser is reduced, thereby achieving the effect of suppressing vibration.

[0035] The present invention is different from the traditional active vibration controller and active flow field control device. The active vibration suppression device has low energy consumption and is less dependent on the riser 8 device itself. It will not increase the complexity of the system. It can be installed and used immediately, is easy to install, and is easy to maintain. It also has a wide range of applications and is highly adaptable to the vibration suppression problems of different engineering equipment.

[0036] The invention has the characteristics of simple structure, simple technology, easy installation, real-time monitoring and adjustment, good vibration suppression effect and wide applicability. Numerical simulation has proved that the rotation of the vibration reduction fins around the pipe sleeve under PID control can effectively reduce the vortex-induced vibration of the riser. The numerical model is as follows Figure 7 As shown. The computational domain size of the numerical model is 40D×20D, and the origin of the computational domain is set at the center of the circle. The left boundary is 10D away from the origin and is set as the velocity inlet; the right boundary is 30D away from the origin and is set as the pressure outlet; the upper and lower boundaries are 10D away from the origin and are set as wall conditions. There are four vibration-damping fins H1, H2, H3 and H4 distributed in a clockwise direction around the circle. In order to demonstrate the feasibility and effectiveness of the vibration suppression device, two calculation conditions shown in Table 1 were set respectively, and the following results were obtained: Figure 8 The vibration suppression effect comparison diagram is shown. It can be seen that the vibration suppression efficiency of the numerical model under two different working conditions can reach more than 90%, and it has good vibration suppression ability.

[0037] In the vibration suppression device, by combining the PID control method, K is achieved after a lot of trial and error training. p , K i and K d The optimal combination of parameters is set, and then the vibration reduction fin rotation control is made in real time for the monitored riser movement speed, acceleration and displacement data to achieve the best vibration suppression effect. As an active marine riser vortex-induced vibration suppression device based on vibration reduction fins, this device can greatly facilitate the installation and disassembly of the device and effectively suppress the vortex-induced vibration of the riser.

[0038] Table 1 Calculation conditions of numerical model

[0039]

[0040] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent replacement and improvement made to the above embodiments without departing from the content of the technical solution of the present invention, based on the technical essence of the present invention, within the spirit and principles of the present invention, still fall within the protection scope of the technical solution of the present invention.

Claims

1. An active marine riser vortex-induced vibration suppression device based on vibration-damping fins, characterized in that: The device comprises a pipe sleeve (7) and a plurality of vibration reduction components. The pipe sleeve (7) is sleeved on a vertical pipe (8) and is detachably connected to the vertical pipe (8). The plurality of vibration reduction components are evenly distributed on the outer periphery of the pipe sleeve (7) along a circumferential direction. The pipe sleeve (7) comprises two semicircular pipe sleeves (10). The two semicircular pipe sleeves (10) are clamped on the outer wall of the vertical pipe (8) via fixing parts.

2. The active marine riser vortex-induced vibration suppression device based on vibration-damping fins according to claim 1 is characterized in that: Each of the vibration-damping components comprises a vibration-damping fin (1), a bearing (2), a fixed rotating shaft (3), two first connecting members (4), a servo motor (5) and a second connecting member (6); the two first connecting members (4) are arranged vertically and opposite to each other; the lower end of each first connecting member (4) is fixedly connected to the outer wall of the pipe sleeve (7), and the upper end is rotatably connected to the side wall of the vibration-damping fin (1); the bearing (2), the fixed rotating shaft (3), the servo motor (5) and the second connecting member (6) are all located in the vibration-damping fin (1); a servo motor (5) is respectively installed at both ends of the second connecting member (6); the output end of the servo motor (5) is fixedly connected to one end of the fixed rotating shaft (3), and the other end of the fixed rotating shaft (3) is connected to the inner side of the upper end of the first connecting member (4) through the bearing (2).

3. The active marine riser vortex-induced vibration suppression device based on vibration-damping fins according to claim 2 is characterized in that: The bearing (2) is installed at the junction of the vibration-damping fin (1) and the first connecting member (4); the outer diameter of the bearing (2) is the same as the size of the opening of the side wall of the vibration-damping fin (1); and the inner diameter of the bearing (2) is the same as the diameter of the fixed rotating shaft (3).

4. The active marine riser vortex-induced vibration suppression device based on vibration-damping fins according to claim 2 is characterized in that: The second connecting member (6) is a circular tube, and the second connecting member (6) is connected to the servo motors (5) at both ends to form a whole.

5. The active marine riser vortex-induced vibration suppression device based on vibration-damping fins according to claim 1 is characterized in that: The two connecting ends of each semicircular pipe sleeve (10) are respectively provided with connecting ear plates (9).

6. The active marine riser vortex-induced vibration suppression device based on vibration-damping fins according to claim 1 is characterized in that: A sensor and an embedded PID are arranged on the inner wall of the pipe sleeve (7).

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