A cavitation sealing device for a ship's air layer drag reduction system

Abstract

The present invention provides a cavitation sealing device for a ship air layer drag reduction system, comprising a sleeve (101) arranged in an air jet hole (12) of the air layer drag reduction system, one end of which is closed and a plurality of holes are provided on the side wall, the other end of the sleeve (101) is connected to a spring connecting rod (103), and the other end of the spring connecting rod (103) is connected to a one-way air outlet valve (8). The present invention utilizes atmospheric pressure to extend the cavitation sealing device downward out of the hull to form an air layer to play a role of gas lubrication; and then utilizes seawater pressure to return the cavitation sealing device to the air jet hole, thereby preventing seawater from carrying marine organisms into the air cavity and preventing seawater from corroding the air cavity and the inner bottom plate of the hull, thereby improving the operational reliability of the air layer drag reduction system, improving the safety of the ship structure, and reducing the number of docking maintenance.

Description

Technical Field

[0001] The present invention relates to the field of shipbuilding, and more particularly to a cavitation sealing device used in a ship air layer drag reduction system. Background Art

[0002] Ship gas drag reduction technology involves injecting air into the bottom of a ship during travel, creating a stable gas lubrication layer that reduces surface frictional resistance. The ship's gas layer drag reduction system consists of an air supply system, an air cavity, and air jets. The air jets are located on the ship's bottom plate and connected to the air cavity. While the ship is moving, the air supply system supplies air into the air cavity, which is then ejected through the air jets to the outside of the hull, forming a drag-reducing gas lubrication layer on the bottom of the hull.

[0003] When a ship is moored at a pier or encountering severe sea conditions while sailing, the ship's air layer drag reduction system should be shut down. However, seawater can easily enter the air cavity through the jet holes on the air layer drag reduction system, carrying marine organisms into the air cavity. In addition, because seawater is corrosive, it will corrode the hull steel plate and the air cavity. If the ship is immersed in seawater for a long time, it will cause corrosion and cracking of the air cavity and bottom plate, thereby affecting the structural safety of the ship. Summary of the Invention

[0004] The purpose of the present invention is to provide an automatic cavitation sealing device for a ship's air layer drag reduction system to solve the problem that seawater enters the air cavity through the jet hole, causing corrosion and cracking, thereby affecting the structural safety of the ship.

[0005] In order to achieve the above-mentioned purpose, the present invention provides a cavitation sealing device for a ship's air layer drag reduction system, including a sleeve arranged in the air jet hole of the air layer drag reduction system, one end of which is closed and the side wall of which is provided with a plurality of holes, the other end of the sleeve is connected to a spring connecting rod, and the other end of the spring connecting rod is connected to a one-way air outlet valve.

[0006] Preferably, a circle of limiting points is provided in the jet hole, and the jet hole passes through the bottom plate of the ship.

[0007] Preferably, a limiting ring is provided at the interface between the inner side of the ship bottom plate and the air jet hole.

[0008] Preferably, the thickness of the ship bottom plate is A, that is, the height of the air jet hole is A and the diameter is B, the height of the cavitation sealing device is D and the diameter is C, D=0.9A, BC=2mm.

[0009] Preferably, the distance between the limiting point and the upper edge of the air injection hole is E, where E=0.2A.

[0010] Preferably, the holes provided on the side wall are within the range AD from the end of the sleeve, AD <E。

[0011] The present invention has the following beneficial effects:

[0012] The present invention utilizes atmospheric pressure to push the cavitation sealing device downward out of the hull to form an air layer to act as a gas lubricant; it can also utilize seawater pressure to send the cavitation sealing device back into the jet hole, preventing seawater from carrying marine organisms into the air cavity, avoiding seawater corrosion of the air cavity and the inner bottom plate of the hull, improving the operational reliability of the air layer drag reduction system, improving the safety of the ship structure, and reducing the number of docking maintenance times.

[0013] The air inlet and outlet systems of the inflation system of the present invention both adopt the air supply equipment and pipelines of the air layer drag reduction system, which can simplify the gas input and output pipelines and save a lot of costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is the overall structural diagram of the ship's air layer drag reduction system;

[0015] Figure 2 is a side view of the cavitation sealing device of the present invention;

[0016] Figure 3 This is the hole sealing device structure of the present invention;

[0017] Figure 4 This is a diagram showing the positional relationship between the air injection hole and the cavitation sealing device of the present invention;

[0018] Figure 5 This is a schematic diagram of the movement process of the cavitation sealing device in the air supply state of the present invention;

[0019] Figure 6 This is a recovery diagram of the cavitation sealing device in the state of stopping air supply of the present invention;

[0020] Among them, 1. cavitation sealing device; 2. cavitation inflation pipeline; 3. inflation system; 4. first remote control valve; 5. limit ring; 6. limit point; 7. second remote control valve; 8. one-way air outlet valve; 101. sleeve; 102. arc ring body; 103. spring connecting rod; 104. air outlet hole; 105. bottom surface of sleeve. DETAILED DESCRIPTION

[0021] The present invention will be further described below with reference to specific embodiments and accompanying drawings.

[0022] like Figure 1As shown, the present invention provides a cavitation sealing device for a ship air layer drag reduction system, including an inflation system 3, which is connected to a pressure stabilizing chamber 11 through a cavitation inflation pipeline 2. The bottom plate of the pressure stabilizing chamber 11 is a ship bottom plate 13, and an air jet hole 12 is provided on the ship bottom plate 13; a first remote control valve 4 is provided on the cavitation inflation pipeline 2; the cavitation inflation pipeline 2 is also connected to an atmospheric connection pipeline, and a second remote control valve 7 is provided on the atmospheric connection pipeline.

[0023] like Figure 2 As shown, a plurality of air injection holes 12 are provided along the length direction of the pressure stabilizing chamber 11 , and the inflation pipeline 2 is connected with the air injection holes 12 through the pressure stabilizing chamber 11 .

[0024] like Figure 3 As shown, the cavitation sealing device 1 comprises a system consisting of a sleeve 101, a circular arc ring 102, a spring connecting rod 103, an air outlet 104, a sleeve bottom surface 105, and an air outlet valve 8. The cavitation sealing device 1 is located within the air jet 12 and can move up and down within the air jet 12. The cavitation sealing device 1 comprises a sleeve 101, with a circular arc ring 102 disposed on one end of the sleeve 101 to limit displacement. A one-way air outlet valve 8 is also disposed within the air jet 12. Several circular holes 104 are disposed at the other end of the sleeve 101, which serve as air outlets for the pressure-stabilizing chamber 11. The one-way air outlet valve 8 is connected to the sleeve bottom surface 105 via a spring connecting rod 103.

[0025] Among them, the one-way air outlet valve 8 is a commonly used marine butterfly check valve with an anti-leakage function, including a valve body and a valve core structure arranged inside the valve body. The interior of the valve body is provided with a sealing anti-leakage mechanism to prevent leakage. The valve core structure includes a central shaft movably mounted inside the valve body, a torsion spring movably mounted on the surface of the central shaft, a right valve plate movably mounted on the right side of the central shaft, and a left valve plate movably mounted on the left side of the central shaft. A left sealing ring and a right sealing ring are respectively mounted on the inner walls of the left and right sides of the valve body, and a right movable ring is mounted on the back of the right valve plate, and a left movable ring is mounted on the front of the left valve plate. Therefore, when the liquid in the pipeline flows backward, the right valve plate and the left valve plate will be in a vertical state with the inner wall of the valve body, the right sealing ring will contact the right movable ring, and the left sealing ring will contact the left movable ring, so that the liquid cannot pass through the valve body. (Chinese Patent: CN215673753U, a marine butterfly check valve with an anti-leakage function)

[0026] When the inflation system 3 is working, under the action of pressure, the one-way air outlet valve 8 automatically opens, and the bottom surface 105 of the sleeve is subjected to a large internal pressure, which pushes the sleeve 101 out of the jet hole 12, exposing the air outlet hole 104, and the gas is ejected through 104 to form an air layer on the bottom of the ship.

[0027] After the gas supply stops, due to the decrease in internal air pressure, the stretched spring link 103 returns to its original state. The spring link 103 pulls the sleeve 101 back to the air jet hole 12. At this time, the external pressure is greater than the internal pressure, and the sleeve 101 is pushed into the innermost part of the air jet hole 12.

[0028] A circle of limit points 6 is provided inside the air jet hole 12, and the width is slightly smaller than the width of the arc ring body 102. The limit points 6 are a circle of protrusions. The limit points 6 cooperate with the arc ring body 102. When sliding to the limit points 6, the sleeve 101 is卡住 to prevent it from falling out of the hull. The limit points 6 limit the air cavity sealing device 1 from falling out of the air cavity. On the air jet hole 12, on the upper surface of the outer plate 13, a circle of limit rings 5 is provided. This limit structure can prevent the air cavity sealing device 1 from being forced into the air charging pipeline 2 by excessive seawater pressure. The air outlet valve 8 is welded to the inner plane of the ship bottom plate 13.

[0029] As Figure 4 shown, the thickness of the outer plate is A, the height of the air jet hole 12 is A, the diameter is B, the height of the air cavity sealing device 1 is D, the diameter is C, D = 0.9A, B - C = 2mm; the limit ring 5 extends 2mm into the inner edge of the air cavity sealing device 1. The diameter of the arc ring body 102 is F, F = 0.5*(B - C), the distance from the limit points 6 to the uppermost edge of the air jet hole 12 is E, E = 0.2A. The width of the limit ring 5 is less than or equal to F. To ensure that gas can be ejected, the round hole 104 is set within the range of A - D from the bottom, A - D < E, so as to ensure that the air outlet hole 104 is completely exposed and ensure the air output volume.

[0030] As Figure 5 shown, when the air layer drag reduction system is in operation, open the first remote control valve 4 on the air charging pipeline 2 and close the second remote control valve 7 on the atmosphere connection pipeline. The air charging system 3 charges the pressure stabilizing cavity 11 through the air charging pipeline 2. The air outlet valve 8 in the air jet hole 12 is opened under the action of gas pressure. When the internal pressure is greater than the external pressure, the sleeve 101 is pushed out of the air jet hole 12, exposing the air outlet hole 104, and the gas is ejected through 104 to form an air layer at the bottom of the ship.

[0031] As Figure 6 shown, when the air layer drag reduction system stops operating, turn off the air charging system 3, close the first remote control valve 4 on the air charging pipeline 2, open the second remote control valve 7. The gas in the pressure stabilizing cavity 11 is discharged to the atmosphere through the second remote control valve 7. The air outlet valve 8 has no pressure acting on it and automatically closes. At this time, without the action of internal pressure, the spring link 103 returns to its original state and pulls the sleeve 101 back into the air jet hole. Due to the external pressure being greater than the internal pressure, the sleeve 101 is pushed to the limit ring 5. The bottom 105 of the sleeve and the air outlet valve 8 prevent external seawater from entering the air cavity, playing a protective role for the air cavity, and close the second remote control valve 7.

[0032] The cavitation sealing device 1 has a certain friction force and moves up and down under the action of gas pressure and seawater pressure, and remains in place when there is no external pressure.

[0033] The air inlet and outlet systems of the inflation system 3 both use the air supply equipment and pipelines of the air layer drag reduction system, saving a set of air supply equipment.

[0034] In order to ensure that the cavitation sealing device 1 is detached from the hull when it moves downward, a limit ring 5 is provided. When the spring connecting rod fails, the sleeve 101 moves downward under the gas pressure until the arc ring body 102 is stuck at the limit ring 5 and stops, and then the air outlet 104 continues to spray air, which plays the role of air lubrication and will not detach from the bottom of the ship.

[0035] In order to ensure that the cavitation sealing device 1 is not pushed into the pressure-stabilizing chamber 11 by the external water pressure when it moves upward, and then loses its sealing function, a limit ring 5 is set on the upper edge of the outlet valve 8. When the external water pressure is too high, the cavitation sealing device 1 can also be restricted in the air jet hole.

[0036] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A cavitation sealing device for a ship air layer drag reduction system, characterized by: The cavitation sealing device (1) comprises a system consisting of a sleeve (101), an arc ring body (102), a spring connecting rod (103), an air outlet hole (104), a sleeve bottom surface (105) and a one-way air outlet valve (8); The cavitation sealing device (1) is arranged in an air jet hole (12) of an air layer drag reduction system, and the air jet hole (12) penetrates a bottom plate (13) of a ship; One end of the sleeve (101) is the closed sleeve bottom surface (105) and a plurality of the air outlet holes (104) are provided on the side wall. The outer edge of the other end of the sleeve (101) is provided with the arc ring body (102). The arc ring body (102) and the inner wall of the air jet hole (12) are provided with a circle of limiting points (6) for cooperation and limitation. A limiting ring (5) is provided at the interface between the inner side of the ship bottom plate (13) and the air jet hole (12); The one-way air outlet valve (8) is arranged in the air jet hole (12) and welded to the inner plane of the ship bottom plate (13). The one-way air outlet valve (8) is connected to the sleeve bottom surface (105) through the spring connecting rod (103).

2. The cavitation sealing device for a ship air layer drag reduction system according to claim 1, characterized in that: The thickness of the ship bottom plate (13) is A, that is, the height of the jet hole (12) is A and the diameter is B, the height of the cavitation sealing device is D and the diameter is C, D=0.9A, BC=2mm.

3. The cavitation sealing device for a ship air layer drag reduction system according to claim 2, characterized in that: The distance between the limiting point (6) and the upper edge of the jet hole (12) is E, where E=0.2A.

4. The cavitation sealing device for a ship air layer drag reduction system according to claim 3, characterized in that: The plurality of air outlet holes (104) provided on the side wall are within a range AD from the end of the sleeve (101), AD <E。

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