CN208076120U - A kind of deep-sea high-fineness ratio catenary riser vortex-induced vibration bath scaled model experimental device - Google Patents

Abstract

The utility model relates to a deep sea large slenderness ratio catenary riser vortex-induced vibration model experiment device, which is characterized in that it includes a trailer, a pipe frame, a bottom tray, a limiter, a certain pulley, a steel wire rope, A steel plate, an L-shaped operating platform, a combination of solid steel pipe and right-angle vertical slats, a variable tension system, two universal joints, and multiple acceleration sensors. The trailer is welded to the pipe support, the pipe support and the bottom tray are connected by bolts, the top of the support pipe is fixed to an L-shaped operating platform, and the position of the central axis of the long side is fixed. Fix a certain pulley at the end; the limiter is installed on the bottom tray, and a limit hole is set in the lower part of the middle; a universal hinge is installed in the middle of the far right-angle side of the bottom tray and a catenary riser model is set between the fixed pulley ; The variable tension system includes a tension sensor, a tensioner and an electric push-pull rod.

Description

A model experimental device for vortex-induced vibration of catenary risers with large slenderness ratio in deep sea

technical field

The invention relates to a deep-sea large-slender-ratio catenary riser vortex-induced vibration model experimental device, in particular to a deep-sea large-slender-ratio catenary riser model vortex-induced vibration experimental device with a small bending stiffness .

Background technique

The marine riser is the key structure connecting the floating platform and the subsea drilling system. Due to the influence of factors such as the complexity of the deep water environment and the diversity of pipeline structures, under the action of ocean currents, alternate vortex shedding will occur on both sides of the cylindrical structure, resulting in periodically changing fluid forces, causing the riser to vibrate and the riser to vibrate. It also reacts on the flow field. This typical fluid-solid coupling phenomenon is called "vortex induced vibration". Deepwater risers are easily damaged under the influence of vortex-induced vibration. In order to reduce the damage of vortex-induced vibration to the flexible riser, the first task is to deeply understand the vortex-induced vibration mechanism of the flexible riser under various hydrodynamic environments. Carrying out the vortex-induced vibration physical model experiment of the catenary riser model with large slenderness ratio is one of the effective methods at the present stage. It can provide a basis for judging the accuracy of numerical simulation, and form the viscous force, mass ratio, and damping ratio. The vortex-induced vibration force coefficient database with higher accuracy and wider coverage, such as , axial tension, etc., provides data basis for actual engineering application analysis.

In the past one hundred years, vortex induced vibration has been extensively studied by scholars all over the world. Phenomena such as frequency locking, maximum dynamic response, excitation mode, and wake mode of vortex-induced vibration of cylindrical bodies have been well explained in theory. Most of the studies on slender flexible pipes are on slender vertical flexible risers and rigid catenary (SCR). In recent years, Vandiver has observed that different modes of locking may occur at different positions in shear-flowing, high-slender-ratio risers. At the same time, Vandiver proposed that when locking occurs, the change of axial tension may cause the change of one order mode to another order mode. For steel catenary risers, Larsen et al. analyzed the vortex-induced vibration of steel catenary risers in time domain and frequency domain. Srinil et al. improved the reduced-order model for the study of vortex-induced vibration of catenary risers in ocean currents. For the catenary riser model tests carried out in the past, in order to maintain the catenary shape of the SCR, the bending stiffness of the riser model was increased at the cost of ignoring the stiffness of the riser model defined by the scientific scale, which seriously affected the accuracy of the experiment. Huge influence; currently in domestic and foreign riser model tests, there are few vortex-induced vibration experimental studies that consider both wave load and flow velocity load, which deviates from the actual engineering environment. The "a deep-sea large slender Compared with the catenary riser vortex-induced vibration model experiment device", this problem can be effectively solved; The position of the catenary line cannot be retained due to displacement. The stopper at the catenary contact point can not only maintain the position of the catenary line of the standpipe, but also the elastic connection between it and the standpipe can effectively simulate the ground contact between the sand and the standpipe in actual working conditions. Friction and suction for pipe segments.

Contents of the invention

In view of the above problems, the utility model aims to provide a reliable and stable deep-sea large-slender-ratio catenary riser vortex-induced vibration model experimental device. This experimental device can truly and effectively simulate the vortex-induced vibration characteristics of the large-slender-ratio catenary riser model in the actual physical model test.

In order to achieve the above object, the technical solution adopted by the present invention is: the utility model relates to a deep-sea large slenderness ratio catenary riser vortex-induced vibration model experimental device, which is characterized in that: the experimental device includes a trailer, a pipe support , a bottom tray, a limiter, a certain pulley, a steel wire rope, a steel plate, an L-shaped operating platform, a solid steel tube and a combination of right-angle vertical slats, a variable tension system, two universal hinges and a plurality of acceleration sensors; the trailer runs on fixed rails at both ends, and the middle part is connected with a steel plate that can move up and down, and the steel plate is welded to the pipe support; The bottom tray is fixedly connected with the bottom of the trailer through bolts; the bottom tray covers the bottom surface of the pipe support, and a universal hinge is installed in the middle of the far right-angled side of the bottom tray; the stopper is installed on the bottom tray, and the stopper is in the middle. A limit hole is set at the lower part; an L-shaped operating platform is fixedly connected to the top of the pipe support, and the position of the central axis of the long side of the L-shaped operating platform is fixed to a right-angled vertical slat, and the end of the vertical slat far away from the pipe support passes through a solid steel A round pipe is made, and a certain pulley is fixed on the top of the round pipe; a catenary riser model is set between the universal hinge in the middle of the far right-angle side of the bottom tray and the fixed pulley; the steel wire rope bypasses the fixed pulley and a threaded screw connected to a universal hinge, and the universal hinge is connected to the riser model; the variable tension system includes a tension sensor, a tensioner, and an electric push-pull, and the steel wire rope is connected to the tension sensor, tensioned The device is fixed on the wire rope, and the wire rope goes around the fixed pulley and connects with the electric push-pull rod.

The top of the catenary riser model is connected with the universal hinge, and the universal hinge is connected with a threaded screw and connected with the wire rope bypassing the fixed pulley, and the other end of the wire rope bypasses the fixed pulley to connect the tension sensor, tension Finally, the device is connected with the electric push-pull rod; the bottom end of the catenary riser model is connected with the universal hinge at the middle position of the far right-angle side of the bottom tray, and the touch point passes through the limit hole on the limiter. The limiter is connected to the bottom tray by a controllable elastic constant spring, and the controllable elastic constant spring is fixedly connected to the bottom tray by bolts at equal intervals. The controllable elastic constant spring is fixedly connected to the bottom tray by bolts at equal intervals.

After the present invention adopts the above-mentioned technical scheme, it has the following advantages: 1. Since the present invention adopts a variable tension system, it can effectively simulate the vortex-induced vibration phenomenon of the catenary riser in the deep sea, and the electric push-pull rod bypasses the fixed pulley and the riser through the steel wire rope The model connection, not directly connected with the riser, can effectively reduce the interference of the vibration of the electric push-pull rod to the vortex-induced vibration of the riser model. 2. Since the present invention makes the catenary riser placed vertically instead of horizontally, it is closer to the actual sea conditions and the simulation results are more accurate. 3. Due to the setting of the limiter, not only the riser model with smaller bending stiffness is allowed to be used in the test, but also the elastic setting of the limiter can simulate the interaction force between the contact point of the catenary riser and the sediment. 4. The present invention can give the catenary riser model initial top tension and pulling force through the tension system by acting on the steel wire rope, and at the same time adjust the vertical distance between the limiter and the riser model suspension point to adapt to the suspension inclination of the catenary riser .

Description of drawings

Fig. 1 is the structural representation of the utility model.

Fig. 2 is a structural schematic diagram of the tension system of the utility model.

Fig. 3 is a three-dimensional perspective view of the riser model of the utility model.

Detailed ways:

The utility model includes a trailer 1, a pipe frame 2, a bottom tray 7, a limiter 4, a certain pulley 5, a steel wire rope 10, an L-shaped operating platform 9, two universal hinges 6, and a suspension chain Line riser model 8, a steel plate 3 and a plurality of acceleration sensors, a solid steel pipe and a right-angle vertical slat combination, a variable tension system, the variable tension system includes an electric push-pull rod 13, a pulling force Sensor 11 and tensioner 12. The trailer 1 is kept parallel to the ground, and is welded to the pipe frame through a bolt-connected vertical steel plate whose height can be adjusted up and down, and runs along its fixed track. The pipe support 2 is welded by a rectangular truss and fixed to the bottom tray by bolts at equal intervals. During the experiment, because the height adjustability of the steel plate 3 can effectively control the water entry depth of the riser model, the branch pipe frame drives the suspension line riser model with the movement of the trailer to simulate the effect of sea waves and currents on the ocean riser.

The top of the branch pipe support 2 is fixedly connected to an L-shaped operating platform 9, and the position of the central axis of the long side of the L-shaped operating platform 9 is fixed. A solid steel pipe and a right-angle vertical slat are combined; Line riser model 8—the initial force can also control the position and angle of the vertical riser.

The pipe support and the bottom tray are fixedly connected to the bottom of the trailer through bolts; the limiter is installed on the bottom tray through a spring with a controllable elastic coefficient, and a limit hole is set at the lower part of the limiter, and the contact point of the standpipe model passes through the limit device, so as to realize the function of fixing the riser model. The bottom tray covers the bottom surface of the pipe support. A universal hinge is arranged in the middle of the far right-angle side of the bottom tray. A catenary riser model is set between the universal hinge and the fixed pulley. The universal hinge at the position is hinged and passed through the limit hole of the limiter and then connected with the upper suspended universal hinge, the upper suspended universal hinge is connected with a threaded screw, and then connected with the steel wire rope, so that the catenary riser and While the experimental device is fixed, the bending moment at the end of the riser is guaranteed to be zero.

The variable tension system includes an electric push-pull rod, a tension sensor and a tensioner connected in series in the vertical direction. The steel wire rope is connected with the tension sensor, the tensioner is fixed on the steel wire rope, and the steel wire rope bypasses the fixed pulley and is connected with the electric push-pull rod. The electric push-pull rod is connected to the steel wire, and the steel wire rope bypassing the fixed pulley is pulled to apply force to the catenary riser, and the initial pretension is provided for the catenary riser model in the experiment by adjusting the tensioner.

Arrange an acceleration sensor at every 60 cm of the catenary riser model to measure the movement of the riser model under different load combinations and different working conditions, so as to study the wave-current combination of the catenary riser with large slenderness ratio Vortex-induced vibration of a riser model under action.

Claims (2)

1. A deep-sea large slenderness ratio catenary riser vortex-induced vibration model experimental device is characterized in that: said experimental device includes a trailer, a pipe support, a bottom tray, a stopper, a certain pulley, a steel wire rope, a steel plate, an L-shaped operating platform, a solid steel pipe and right-angle vertical slat assembly, a variable tension system, two universal hinges, and multiple acceleration sensors; the trailer is fixed on both ends of the track The middle part is connected with a steel plate that can move up and down, and the steel plate is welded to the pipe support frame; the front view of the pipe support frame is a right-angled trapezoidal shape, and the side view is rectangular, and the pipe support frame and the bottom tray are fixedly connected to the bottom of the trailer through bolts; The bottom tray covers the bottom surface of the pipe support, and a universal hinge is installed in the middle of the far right-angle side of the bottom tray; the stopper is installed on the bottom tray, and a limit hole is set at the lower part of the stopper; the top of the support pipe is fixed with a L The L-shaped operating platform has a fixed right-angled vertical slat at the central axis of the long side of the L-shaped operating platform, and the far end of the vertical slat pipe frame passes through a solid steel round tube, and a certain pulley is fixed at the top of the round tube; the bottom A catenary riser model is set between the universal hinge at the middle position of the far right-angle side of the tray and the fixed pulley; The riser model is connected; the variable tension system includes a tension sensor, a tensioner, and an electric push-pull. The tie rod is connected. 2. A kind of deep-sea large slenderness ratio catenary riser vortex-induced vibration model experimental device according to claim 1, characterized in that the top of the catenary riser model is connected with the universal hinge, and the universal joint The hinge is connected with a threaded screw and finally connected with the wire rope bypassing the fixed pulley; the bottom end of the catenary riser model is connected with the universal hinge at the middle position of the far right-angle side of the bottom tray, and the touch point passes through the limit The limiting hole on the limiter; the limiter is connected to the bottom tray with a controllable elastic constant spring, and the controllable elastic constant spring is fixedly connected to the bottom tray through bolts at equal intervals.