High-efficiency bubble generating device for ship

Abstract

The application discloses a kind of marine high-efficiency bubble generating device, it includes flow guide plate and flow guide plate, and top plate and two side plates are provided between flow guide plate and flow guide plate;Flow guide plate, flow guide plate, top plate and two side plates are enclosed into concave water-gas mixing chamber;Water-gas mixing chamber is equipped with multiple exhaust pipes, and exhaust pipe extends along the longitudinal direction of ship;Two sides of exhaust pipe are each equipped with exhaust hole capable of exhausting to horizontal direction.The application can improve water-gas mixing efficiency, bubble distribution is uniform, which is conducive to inhibiting the escape of bubble in boundary layer, and increasing drag reduction efficiency.

Description

Technical Field

[0001] This invention relates to the field of marine technology, and in particular to a high-efficiency bubble generator for marine applications. Background Technology

[0002] The bubble generator is a core component of ship bubble drag reduction. Generally, ship bubble drag reduction systems require several bubble-generating air chambers installed at the hull bottom to generate bubbles during navigation. The China Classification Society (CCS) published the "Inspection Guidelines for Ship Air Lubrication Drag Reduction Systems" in April 2026, indicating that this technology is still in the development stage. The guidelines provide a schematic diagram of the components of an air lubrication drag reduction system.

[0003] Traditional bubble generators require a compressed air chamber, as illustrated in patent application CN104254478A, which discloses an air lubrication system. This patent relates to a system for providing an air lubrication layer, its operation method, and a drainage vessel. The system provides an air lubrication layer between the generally flat bottom of the vessel's hull and the water flowing beneath it as the vessel moves through water. The system includes sidewalls and a top wall defining a cavity with an opening located in an interface plane transverse to the sidewalls, approximately flush with the flat bottom. Viewed along the length of the cavity, the opening has a front end and a rear end. An air inlet is spaced apart from the opening to introduce air into the cavity. The length of the cavity opening is between 2 m and 10 m, and the distance from the top wall to the interface plane is between 0.2 m and 0.5 m. This approach generates bubbles by forming a water-air interface within the compressed air chamber, utilizing the Kelvin-Helmholtz effect. Therefore, it requires the arrangement of a compressed air chamber and utilizes the instability of the water-air interface within it to generate bubbles. This method of bubble generation requires a high degree of stability in the internal water-air interface; the quality of the bubbles generated may decrease when the hull tilts in waves.

[0004] Patent application CN214001953U discloses a bubble lubrication drag reduction system and a ship. The bubble lubrication drag reduction system includes an air compressor, an air duct, and a bubble generator. The bubble generator includes a top plate, side plates, an exhaust port plate, a guide curved plate, and a deflection curved plate. The exhaust port plate is located below the top plate, and the top plate, side plates, and exhaust port plate surround and form a compressed air chamber. The air outlet of the air compressor is connected to the compressed air chamber via an air duct. Along the ship's direction of travel, the top of the guide curved plate is connected to the front side of the exhaust port plate, and the top of the deflection curved plate is connected to the rear side of the exhaust port plate, with the guide curved plate and deflection curved plate bending in opposite directions. This design discharges air into the water through the exhaust port plate and arranges a water-air mixing area below the exhaust port plate, utilizing water flow disturbance to achieve uniform water-air mixing. However, this bubble generator design is relatively complex.

[0005] Another type of bubble generator is disclosed in patent application CN116476971A, which describes a bubble drag reduction system and a ship including such a system. This bubble drag reduction system includes a bottom plate, a top wall, side walls, a rear wall, a vent plate, and a cover plate. The bottom plate is fixed to the outer hull and conforms to the outer surface of the ship; side walls are fixed to the bottom plate. A top wall is fixed to the top of the side walls, a vent plate is detachably fixed in the middle, and a cover plate is detachably fixed to the bottom. A support wall is provided between the vent plate and the top wall. The support wall, vent plate, top wall, and side walls together form a pressure stabilizing chamber, and an air inlet is opened on the top wall at the pressure stabilizing chamber. The vent plate, side walls, and cover plate together form an exhaust chamber with one side opening, which communicates with the pressure stabilizing chamber. A rear wall extending obliquely downwards and rearwards is provided at the top of the opening of the exhaust chamber, and a gap exists between the rear wall and the cover plate, forming an air outlet. This solution also requires a compressed air chamber, and the water-air mixing is uncontrollable.

[0006] Most existing bubble generators use compressed air chambers, which suffer from drawbacks such as complex structure, uncontrollable water-air mixing, and low mixing efficiency. When a ship's buoyancy changes in waves, such as tilting or sinking, the pressure inside its compressed air chamber also changes, affecting the quality of the generated bubbles and reducing drag reduction. Summary of the Invention

[0007] In order to overcome the above-mentioned defects in the prior art, the present invention provides a marine high-efficiency bubble generator.

[0008] The present invention solves the above-mentioned technical problems through the following technical solution: A high-efficiency bubble generator for marine applications includes an incoming flow guide plate and an outgoing flow guide plate fixed to the hull plating of a ship. A top plate and two side plates are provided between the incoming flow guide plate and the outgoing flow guide plate. The incoming flow guide plate, the outgoing flow guide plate, the top plate, and the two side plates form a concave water-air mixing chamber. Multiple exhaust pipes are provided in the water-air mixing chamber, extending longitudinally along the ship. The multiple exhaust pipes form an exhaust pipe array. Each side of the exhaust pipe has an exhaust hole capable of venting in a horizontal direction. The diameter of the exhaust hole D1 = 0.2 to 0.4D, where D is the diameter of the exhaust pipe. The distance between adjacent exhaust holes dx = 2 to 10D. The front end of the incoming flow guide plate, the rear end of the outgoing flow guide plate, and the bottom end of the side plates form the bottom plane of the chamber. The distance between the bottom plane of the chamber and the incoming flow guide plate is the bottom length L of the water-air mixing chamber. L = 0.01 to 0.05 Lpp, where Lpp is the ship length.

[0009] Furthermore, the length of the top plate between the incoming flow guide plate and the outgoing flow guide plate is the top length L2 of the water-air mixing chamber; L2 = 0.4~0.7 L.

[0010] Furthermore, the central axes of the multiple exhaust pipes are located in the same plane; the plane in which the central axis of the exhaust pipe is located is the pipe axis plane, and the ratio of the total cross-sectional area S1 of the exhaust pipe on the pipe axis plane to the cross-sectional area S0 of the water-air mixing chamber on the pipe axis plane is S1 / S0 = 0.2 to 0.5; the pipe axis plane is parallel to the bottom plane of the chamber.

[0011] Furthermore, the distance between the top plate and the bottom plane of the chamber is the height H of the water-air mixing chamber; H = 0.2~2.0m; the distance between the pipe axis plane and the bottom plane of the chamber is the height h of the exhaust pipe; h = 0.05~0.5m.

[0012] Furthermore, the exhaust pipe diameter D = 50–200 mm.

[0013] Furthermore, the rear end of the exhaust pipe is a closed end, and the exhaust pipe only has exhaust holes on both sides.

[0014] Furthermore, the marine high-efficiency bubble generator also includes an air inlet pipe; exhaust pipes are all connected to the air inlet pipe; the air inlet pipe passes through the top plate, or the air inlet pipe is located outside the incoming flow guide plate.

[0015] Furthermore, there is a gap between the rear end of the exhaust pipe and the deflection guide plate; or the rear end of the exhaust pipe is fixed to the deflection guide plate.

[0016] Furthermore, the hull plating refers to the hull plating on the side of the ship.

[0017] Furthermore, the hull plating is the outer plating of the ship's bottom.

[0018] The beneficial effects of this invention are as follows: This device places the exhaust pipe directly in the water, discharging air directly into the water through the exhaust holes on the pipe. This method produces a higher degree of water-air mixing, improving water-air mixing efficiency and generating a high-quality, uniformly distributed bubble layer. The uniform bubble distribution helps suppress bubble escape within the boundary layer, increasing drag reduction efficiency. This device can be used for drag reduction at the bottom of ships or on the sides of ships; its structure is simple, easy to manufacture, and low in cost, allowing for widespread application. Attached Figure Description

[0019] Figure 1 This is a perspective view of the first embodiment of the present invention.

[0020] Figure 2 for Figure 1 Top view of the device shown.

[0021] Figure 3 for Figure 2 View from A in the middle.

[0022] Figure 4 for Figure 3A schematic diagram showing the dimensions of the structure.

[0023] Figure 5 for Figure 1 A schematic diagram of the exhaust pipe in the device shown.

[0024] Figure 6 This is a schematic diagram of the flow of water and air bubbles within the water-air mixing chamber.

[0025] Figure 7 This is a schematic diagram of the second embodiment of the present invention.

[0026] Figure 8 This is a schematic diagram of the third embodiment of the present invention.

[0027] Figure 9 This is a schematic diagram of the invention applied to the bottom of a ship.

[0028] Figure 10 This is a schematic diagram of the invention applied to the side of a ship. Detailed Implementation

[0029] The present invention will be described more clearly and completely below with reference to a preferred embodiment and the accompanying drawings.

[0030] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, a marine high-efficiency bubble generator includes an incoming flow guide plate 11 and an outgoing flow guide plate 12 fixed to the outer plate 10 of the ship. A top plate 13 and two side plates 14 are provided between the incoming flow guide plate 11 and the outgoing flow guide plate 12. The incoming flow guide plate 11, the outgoing flow guide plate 12, the top plate 13 and the two side plates 14 form a concave water-air mixing chamber.

[0031] The water-air mixing chamber is equipped with multiple exhaust pipes 20, which extend longitudinally along the ship. These multiple exhaust pipes form an exhaust pipe array. The exhaust pipes are connected to compressed air.

[0032] The exhaust pipe 20 has exhaust holes 21 on both sides, which are capable of venting exhaust in the horizontal direction. The exhaust hole is located at the point where the outer diameter of the exhaust pipe is at its maximum in the horizontal direction.

[0033] In this embodiment, the central axes of the multiple exhaust pipes are located in the same plane; the plane in which the central axes of the exhaust pipes are located is the pipe axis plane.

[0034] The ratio of the total cross-sectional area S1 of the exhaust pipe on the pipe axis plane to the cross-sectional area S0 of the water-air mixing chamber on the pipe axis plane is S1 / S0 = 0.2 to 0.5.

[0035] The front end of the incoming flow guide plate, the rear end of the outgoing flow guide plate, and the bottom end of the side plate form the bottom plane of the chamber; the tube axis plane is parallel to the bottom plane of the chamber.

[0036] The distance between the bottom plane of the chamber and the inflow guide plate and the outflow guide plate is the bottom length L of the water-air mixing chamber; L = 0.01~0.05 Lpp, where Lpp is the length of the ship.

[0037] The length of the top plate 13 between the incoming flow guide plate and the outgoing flow guide plate is the top length L2 of the water-air mixing chamber; L2 = 0.4~0.7 L.

[0038] The diameter of the exhaust port D1 is 0.2 to 0.4D, where D is the diameter of the exhaust pipe; the distance between adjacent exhaust ports on the exhaust pipe is dx = 2 to 10D. In this embodiment, the diameter of the exhaust pipe D is 50 to 200 mm.

[0039] The distance between the top plate 13 and the bottom plane of the chamber is the height H of the water-air mixing chamber; H = 0.2 to 2.0 m; the distance between the pipe axis plane and the bottom plane of the chamber is the height h of the exhaust pipe; h = 0.05 to 0.5 m.

[0040] The exhaust pipe has a closed end at the rear, and exhaust ports are only provided on both sides.

[0041] In another embodiment, the central axis of the exhaust pipe may not be located in the same plane.

[0042] The marine high-efficiency bubble generator also includes an air inlet pipe; the exhaust pipe is connected to the air inlet pipe 22; the air inlet pipe passes through the top plate.

[0043] In other implementations, such as Figure 7 and Figure 8 As shown, the exhaust pipe 20 passes through the inlet guide plate 11, and the intake pipe 22 is located outside the inlet guide plate 11.

[0044] The rear end of the exhaust pipe and the deflector plate may or may not be connected.

[0045] exist Figure 3 The embodiments shown and Figure 7 In the embodiment shown, there is a gap between the rear end of the exhaust pipe 20 and the deflection guide plate 12, and the rear end of the exhaust pipe and the deflection guide plate are not connected.

[0046] exist Figure 8 In the embodiment shown, the rear end of the exhaust pipe 20 is fixed to the deflection guide plate 12.

[0047] The marine high-efficiency bubble generator of the present invention can be installed on the bottom of the ship or on the side of the ship.

[0048] In one scenario, the hull plating is the same as the hull plating at the bottom of the ship. For example... Figure 9 As shown, the marine high-efficiency bubble generator 30 of the present invention is installed on the bottom of the ship.

[0049] In another scenario, the hull plating is located on the side of the ship. For example... Figure 10 As shown, the marine high-efficiency bubble generator 30 of the present invention is installed on the side of the ship.

[0050] This device includes an inflow guide plate, an outflow guide plate, a top plate, and side plates that form a water-air mixing chamber, as well as an exhaust pipe disposed within the water-air mixing chamber. The exhaust pipe has exhaust holes, which ensure thorough mixing within the water-air mixing chamber, resulting in a more uniform bubble distribution and high bubble generation efficiency. The exhaust holes discharge air horizontally, and the water flow direction outside the exhaust holes is perpendicular to the horizontal direction. The exhaust direction of the exhaust holes is also perpendicular to the water flow direction outside the exhaust holes, further enhancing the uniformity of water-air mixing.

[0051] When the water flows upward or downward in the water-air mixing chamber, the flow direction of the water outside the exhaust port is perpendicular to the exhaust direction. The shearing effect of the water flow on the air is large, resulting in high water-air mixing efficiency. Figure 6 In the diagram, arrows indicate the flow direction of water within the water-air mixing chamber, and circles represent air bubbles. In the aforementioned embodiments, the flow of water and air bubbles within the water-air mixing chamber is as follows: Figure 6 As shown.

[0052] This device places the exhaust pipe directly in the water and discharges air directly into the water through the exhaust holes on the exhaust pipe. This method produces bubbles with higher water-air mixing and more uniform bubble distribution, which helps to suppress the escape of bubbles in the boundary layer and increase drag reduction efficiency.

[0053] Compared with existing technologies, this device uses an air pipeline to directly exhaust air into the water, improving the water-air mixing efficiency and producing a high-quality, uniformly distributed bubble layer.

[0054] This device can be used to generate bubbles not only at the bottom of the ship but also on the sides. Therefore, it can be used for drag reduction at both the bottom and sides of the ship.

[0055] This device has a simple structure, is easy to manufacture, and has low manufacturing cost, making it suitable for widespread application.

[0056] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A marine high-efficiency bubble generator, comprising an incoming flow guide plate and an outgoing flow guide plate fixed to the hull plating of a ship, wherein a top plate and two side plates are disposed between the incoming flow guide plate and the outgoing flow guide plate; the incoming flow guide plate, the outgoing flow guide plate, the top plate, and the two side plates form a concave water-air mixing chamber; characterized in that, The water-air mixing chamber is equipped with multiple exhaust pipes that extend longitudinally along the ship. Each side of the exhaust pipe has an exhaust port that can exhaust air horizontally. The diameter of the exhaust port is D1 = 0.2 to 0.4 D, where D is the diameter of the exhaust pipe. The distance between adjacent exhaust ports is dx = 2 to 10 D. The front end of the incoming flow guide plate, the rear end of the outgoing flow guide plate, and the bottom end of the side plate form the bottom plane of the chamber. The distance between the bottom plane of the chamber and the incoming flow guide plate is the bottom length L of the water-air mixing chamber. L = 0.01 to 0.05 Lpp, where Lpp is the ship length.

2. The marine high-efficiency bubble generator as described in claim 1, characterized in that, The length of the top plate between the incoming flow guide plate and the outgoing flow guide plate is the top length L2 of the water-air mixing chamber; L2 = 0.4~0.7 L.

3. The marine high-efficiency bubble generator as described in claim 1, characterized in that, The central axes of the multiple exhaust pipes are located in the same plane; the plane in which the central axis of the exhaust pipe is located is the pipe axis plane, and the ratio of the total cross-sectional area S1 of the exhaust pipe on the pipe axis plane to the cross-sectional area S0 of the water-air mixing chamber on the pipe axis plane is S1 / S0 = 0.2 to 0.5; the pipe axis plane is parallel to the bottom plane of the chamber.

4. The marine high-efficiency bubble generator as described in claim 1, characterized in that, The distance between the top plate and the bottom plane of the chamber is the height H of the water-air mixing chamber; H = 0.2~2.0 m; the distance between the pipe axis plane and the bottom plane of the chamber is the height h of the exhaust pipe; h = 0.05~0.5 m.

5. The marine high-efficiency bubble generator as described in claim 1, characterized in that, The exhaust pipe diameter D = 50~200mm.

6. The marine high-efficiency bubble generator as described in claim 1, characterized in that, The exhaust pipe has a closed end at the rear, and exhaust ports are only provided on both sides.

7. The marine high-efficiency bubble generator as described in claim 1, characterized in that, The marine high-efficiency bubble generator also includes an air inlet pipe; exhaust pipes are all connected to the air inlet pipe; the air inlet pipe passes through the top plate, or the air inlet pipe is located outside the incoming flow guide plate.

8. The marine high-efficiency bubble generator as described in claim 1, characterized in that, There is a gap between the rear end of the exhaust pipe and the deflection guide plate; or the rear end of the exhaust pipe is fixed to the deflection guide plate.

9. The marine high-efficiency bubble generator as described in claim 1, characterized in that, The hull plating refers to the outer plating on the side of the ship.

10. The marine high-efficiency bubble generator as described in claim 1, characterized in that, The hull plating refers to the outer plating of the ship's bottom.

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