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CN-121990130-A - Ship draft detection device and detection method

CN121990130ACN 121990130 ACN121990130 ACN 121990130ACN-121990130-A

Abstract

The invention relates to the technical field of ships, in particular to a ship draft detection device and a detection method, comprising a wave stabilizing tube assembly vertically penetrating through a ship body, wherein the wave stabilizing tube assembly comprises a fluid stable static area communicated with an external water area; the invention discloses a non-linear vortex energy dissipation device arranged at the bottom of a wave stabilizing tube assembly, which is characterized in that a rotational flow dissipation cavity is defined in the non-linear vortex energy dissipation device, a tangential throttling channel is arranged on the side wall of the rotational flow dissipation cavity, an axial overflow port is arranged at the top of the rotational flow dissipation cavity, a following assembly is arranged in a fluid static area and comprises a guiding mechanism and a following body, and the flow resistance is automatically switched by utilizing the difference of fluid kinetic energy through the non-linear vortex energy dissipation device arranged at the bottom and the non-linear vortex energy dissipation device is combined with the magnetic suspension following assembly to realize non-contact guiding, so that self-adaptive isolation of high-frequency waves and real-time following of draught change are realized, resonance interference and mechanical friction are eliminated, and the measurement precision under complex sea conditions is ensured.

Inventors

  • XU JIE
  • WANG YIPIN
  • FAN QIANG

Assignees

  • 无锡市兴隆船舶有限公司

Dates

Publication Date
20260508
Application Date
20260409

Claims (10)

  1. 1. A marine vessel draft detection apparatus, comprising: a wave stabilizing tube assembly extending vertically through the hull, the wave stabilizing tube assembly including a fluid static region in communication with the external water area; The nonlinear vortex energy dissipation device is arranged at the bottom of the wave stabilizing tube assembly, a vortex dissipation cavity is defined in the nonlinear vortex energy dissipation device, a tangential throttling channel is arranged on the side wall of the vortex dissipation cavity to force fluid flowing in at a high flow rate to form high-impedance rotary vortex, and an axial overflow port communicated with a fluid stability region is arranged at the top of the vortex dissipation cavity to allow low-flow-rate fluid laminar flow to pass through; the following assembly is arranged in the hydrostatic region and comprises a guide mechanism and a following body, wherein the guide mechanism is configured to establish a non-contact magnetic suspension restraining field between the following body and the inner wall of the hydrostatic region so as to isolate mechanical friction and inhibit parasitic vibration generated by the following body along with the swing of the ship body.
  2. 2. The device of claim 1, wherein the inner wall surface of the swirl dissipative cavity is configured as a solid of revolution gradually contracting upward in the axial direction.
  3. 3. The ship draft detection apparatus according to claim 1, wherein the cross section of the tangential throttle passage has a convergent gradually-changing structure along the inflow direction of the fluid, and the inlet cross section area of the tangential throttle passage is larger than the outlet cross section area thereof.
  4. 4. The ship draft detection device according to claim 1, wherein the nonlinear vortex energy dissipater is provided with a plurality of stages along the axial direction of the wave stabilizing tube assembly, and the vortex dissipation cavities of the adjacent two stages of nonlinear vortex energy dissipaters are communicated.
  5. 5. The ship draft detection apparatus according to claim 1, wherein the axial overflow port is provided with a rectifying grille, and the rectifying grille comprises a plurality of radially distributed guide vanes.
  6. 6. The device for detecting the draft of a ship according to claim 1, wherein the bottom of said follower is provided with a protrusion having a streamline hemispherical or parabolic structure.
  7. 7. The device for detecting the draft of a ship according to claim 1, wherein the follower body is provided with a plurality of damping holes penetrating through the upper surface and the lower surface of the follower body, and the opening area of the damping holes is decreased from top to bottom.
  8. 8. The ship draft detection device according to claim 1, wherein the guiding mechanism comprises permanent magnet arrays uniformly distributed along the circumference of the follower body and magnetic conduction tracks extending along the axial direction of the inner wall of the hydrostatic zone.
  9. 9. The ship draft detection device according to claim 1, wherein a detachable modularized connecting structure is adopted between the nonlinear vortex energy dissipater and the wave stabilizing tube assembly, and a sealing interface is arranged at the connecting position of the nonlinear vortex energy dissipater and the wave stabilizing tube assembly.
  10. 10. A ship draft detection method employing the ship draft detection apparatus according to any one of claims 1 to 9, comprising the steps of: S1, using the nonlinear vortex energy dissipater as the only liquid flow channel between an external water area and the fluid stable static area, and automatically switching a flow resistance mode according to the inflow speed of external fluid, wherein when the fluid is impacted by external waves to cause the fluid to flow in at a high flow speed, the fluid is guided to enter the rotational flow dissipation cavity tangentially, the fluid is excited to generate high-speed rotational vortex, a centrifugal pressure gradient generated by rotation is utilized to construct a high-impedance barrier so as to block the transmission of wave energy to the fluid stable static area; S2, a non-contact magnetic suspension restraining field is established between the following body and the inner wall of the fluid stable static area by utilizing the guide mechanism, so that the following body is suspended on the liquid level of the fluid stable static area, and transverse parasitic vibration generated by the following body along with the swing of the ship body is restrained by utilizing magnetic field repulsive force, so that a stable radar wave reflection reference surface is established; s3, utilizing a ranging sensor arranged at the top of the wave stabilizing tube assembly to transmit a detection beam to a reflection reference surface of the following body and receive an echo, calculating the real-time height of the following body in the fluid stable static region, and further calculating the draft of the ship.

Description

Ship draft detection device and detection method Technical Field The invention relates to the technical field of ships, in particular to a ship draft detection device and a detection method. Background In the field of ship shipping and marine engineering equipment, draft is a core parameter for characterizing ship buoyancy, calculating displacement and guaranteeing navigation safety. In the prior art, in order to realize high-precision draft detection, a non-contact radar or a laser range finder is generally adopted to measure in cooperation with a mechanical structure of a wave stabilizing tube. The wave stabilizing tube is a metal tubular structure which vertically penetrates through the deck of the ship body and leads to the bottom of the ship, and the bottom of the wave stabilizing tube is provided with a through hole which is communicated with outside seawater. The main function of the structure is to be used as a mechanical low-pass filter, and the direct interference of sea surface stormy waves, foam and floaters is shielded by utilizing the physical isolation function of the pipe wall, so that a relatively calm liquid level environment is created in the pipe for the sensor to accurately measure. For example, in a typical bulk carrier draft monitoring system, a radar level gauge is mounted on top of a surge tube to measure the level of the fluid in the tube to counter-drive the ship draft. However, the above-described technique, in practical use, particularly under conventional sea conditions, is capable of isolating most of the high-frequency wave disturbances, but still faces conventional problems of response hysteresis and minute wave residues. To balance connectivity and damping effects, existing stabilizator tube bottoms typically employ a single aperture circular orifice or a simple grating structure. The conventional design often has difficulty in meeting a pair of contradictory requirements of 'fast following draft change' and 'effective wave noise filtering', namely if the through holes are too large, the filtering effect is poor, and if the through holes are too small, the water level change in the pipe is easily caused to be seriously delayed from the actual draft of the ship body, so that the real-time loading and unloading operation is influenced. For this reason, the prior art often relies on the back-end electronic algorithm for long-period moving average filtering, but this does not address the fluid disturbance problem from a physical source. Particularly, when the ship is in open anchor ground or in a surge environment with a wave height exceeding 2 meters, the conventional wave stabilizing tube structure can generate serious measurement failure due to the resonance effect of fluid in the tube, and the method is characterized in that when the fluctuation frequency of external sea waves is close to or coincides with the natural frequency of a fluid column in the wave stabilizing tube, the straight-through or simple throttling tube structure can not dissipate fluid energy, but can induce the liquid level in the tube to generate severe reciprocating oscillation, so that a radar signal reflecting surface is broken, multipath effect or parasitic echo is generated, and further data acquired by a sensor under severe sea conditions are distorted due to extremely low signal-to-noise ratio, so that the draft monitoring precision and the sailing safety of the ship under dynamic sailing and complex sea conditions are seriously restricted. For this purpose, a ship draft detection device and a detection method are proposed. Disclosure of Invention The invention aims to provide a ship draft detection device and a detection method, which solve the problem that a ship wave stabilizing tube is difficult to realize filtering and quick response, and realize non-contact guiding by arranging a nonlinear vortex energy consumer at the bottom, utilizing the fluid kinetic energy difference and combining a magnetic suspension following assembly, thereby realizing self-adaptive isolation of high-frequency waves and real-time following of draft change, eliminating resonance interference and mechanical friction, and guaranteeing the measurement accuracy under complex sea conditions. In order to achieve the above purpose, the present invention provides the following technical solutions: A ship draft detection device comprises a surge tube assembly vertically penetrating through a ship body, wherein the surge tube assembly comprises a fluid steady static area communicated with an external water area, a nonlinear vortex energy dissipation device arranged at the bottom of the surge tube assembly, a vortex dissipation cavity is defined in the nonlinear vortex energy dissipation device, a tangential throttling channel is arranged on the side wall of the vortex dissipation cavity to force fluid flowing in at a high flow rate to form high-impedance rotating vortex, an axial overflow port communicated with the fluid stea