WO2016157633A1 - Frictional resistance-reducing device for air-lubricated ship, and ship - Google Patents

Abstract

A frictional resistance-reducing device (20E) for an air-lubricated ship (10), the frictional resistance-reducing device (20E) being configured to reduce the frictional resistance between the hull (11) and water around the hull (11) by ejecting air around the hull (11), has: an ejector body (31) having a flow passage (31r) through which high-pressure air (AH) supplied from a high-pressure air supply source (14) flows, the ejector body (31) sucking in low-pressure air (AL) into the flow passage (31r), the low-pressure air (AL) having a lower pressure than the high-pressure air (AH); and an air bubble ejection section (21) for ejecting the high-pressure air (AH) and the low-pressure air (AL), which have been discharged from the ejector body (31), to generate air bubbles around the hull (11).

Description

Friction resistance reduction device for air lubricated ship, ship

The present invention relates to a frictional resistance reduction device for an air-lubricated ship and a ship.
This application claims priority based on Japanese Patent Application No. 2015-73479 filed in Japan on March 31, 2015, the contents of which are incorporated herein by reference.

During navigation, the ship receives a frictional resistance generated between the ship and the water where the hull is submerged. Since this frictional resistance becomes a loss with respect to the propulsive force of the hull, it will hinder the improvement of the energy saving effect by reducing the fuel consumption and the reduction of CO ₂ emission.
In view of this, a technique has been proposed in which bubbles generated by jetting air from the hull into the surrounding water are caused to flow along the hull surface to reduce the frictional resistance generated between the hull and the water.

Bubbles can be generated by a blower, for example. This blower is advantageous in that it consumes less energy and is generally suitable for low pressure and large flow rate applications.
On the other hand, in a ship having a deep draft, a large draft pressure acts on the bubble outlet. In this case, in order to send air to the ship bottom and eject it into the water, it is necessary to increase the pressure of the air as compared with the case where the draft is shallow. However, there are cases where the blower cannot obtain a sufficient air discharge pressure. For example, a method using a high-pressure air source such as a compressor capable of increasing the pressure to a higher pressure is conceivable, but energy consumption increases. Therefore, when the draft is deep, the difference between the energy consumption that is reduced by reducing the frictional resistance and the energy consumption that is required to send air is reduced, and the energy saving effect is reduced.

Patent Document 1 discloses a configuration in which a part of pressurized air pressurized by an engine supercharger is supplied to a blower to increase the pressure of air sent to the ship bottom. According to such a configuration, even when the draft is deep, while suppressing an increase in energy consumption, air can be sent to the bottom of the ship and ejected into the water, and as a result, a decrease in energy saving effect can be suppressed. It is possible.

JP 2013-91376 A

The technique described in Patent Document 1 has a complicated configuration in order to adjust the pressure of pressurized air in accordance with the output of the engine and the draft pressure.
Also, if the flow rate of pressurized air supplied from the supercharger cannot be obtained sufficiently, such as when the engine output is low, the engine output is increased only to reduce the frictional resistance, or the high pressure from the compressor, etc. It is necessary to increase the output of the air source, which increases energy consumption. Therefore, there is a possibility that sufficient energy saving effect and CO ₂ emission reduction effect cannot be obtained.
The present invention provides an air-lubricated frictional resistance reduction device for a ship and a ship that can secure a necessary air flow rate while suppressing an increase in the number of parts and obtain a sufficient energy saving effect and a CO ₂ emission reduction effect. The purpose is to do.

According to the first aspect of the present invention, an apparatus for reducing frictional resistance of an air-lubricated ship is an air-lubricated ship that jets air around the hull and reduces frictional resistance generated between the hull and surrounding water. The frictional resistance reduction device includes a flow path through which high-pressure air supplied from a high-pressure air supply source flows, and an ejector that draws low-pressure air having a pressure lower than that of the high-pressure air into the flow path. The frictional resistance reduction device further includes a bubble ejection unit that generates bubbles around the hull by ejecting the high-pressure air and the low-pressure air discharged from the ejector.

Thus, by supplying high-pressure air and low-pressure air from the ejector to the bubble ejection portion, the air flow rate can be increased. Further, it is possible to suppress energy required by devices for generating high-pressure air or low-pressure air without increasing the air flow rate.

According to the second aspect of the present invention, in the friction resistance reducing device for an air-lubricated ship, in the first aspect, the flow path has a gradually reduced cross-sectional area from the upstream side toward the downstream side. It may be.
With this configuration, the flow rate of the high-pressure air increases toward the downstream side in the ejector flow path, thereby generating a negative pressure in the flow path. This negative pressure allows low pressure air to be drawn into the ejector flow path, eliminating the need for a dedicated power source for drawing low pressure air and increasing the air flow rate.

According to the third aspect of the present invention, the frictional resistance reduction device for an air-lubricated ship may be the main machine that propels the hull or the auxiliary machine that supplies air to the main machine in the first or second aspect. Good.
By using compressed air discharged from an auxiliary machine such as a supercharger or the like as high-pressure air in this way, there is no need to provide a separate compressor or the like to generate high-pressure air, and low cost Can be achieved.

According to a fourth aspect of the present invention, in the friction resistance reducing device for an air-lubricated ship, in any one of the first and second aspects, the high-pressure air supply source is a compressor that compresses air. Also good.
With this configuration, high-pressure air can be easily acquired from the atmosphere.

According to a fifth aspect of the present invention, the apparatus for reducing frictional resistance of an air-lubricated ship according to any one of the first to fourth aspects is a bubble recovery unit that recovers the bubbles ejected from the bubble ejection part. The low-pressure air may be the bubbles collected by the bubble collection unit and the air taken from the atmosphere and compressed by a blower.
By using low-pressure air and air compressed by a blower from the bubbles recovered in the bubble recovery unit as low-pressure air in this way, the flow rate of the low-pressure air, that is, the air flow rate supplied to the bubble ejection unit, is easily secured. Can be increased.
Furthermore, by collecting the low-pressure air at the bubble recovery unit, it is possible to reduce the occurrence of bubbles in the screw provided at the stern portion of the hull, so that it is possible to suppress the occurrence of vibration and the reduction in propulsion efficiency.

According to a sixth aspect of the present invention, there is provided a bubble recovery unit for recovering the bubbles ejected from the bubble ejection unit according to any one of the first to fourth aspects. The low-pressure air may be obtained from the bubbles recovered by the bubble recovery unit.
Thus, by obtaining low-pressure air from the bubbles recovered by the bubble recovery unit, it is possible to reduce the equipment cost for generating low-pressure air.
Furthermore, by collecting the low-pressure air at the bubble recovery unit, it is possible to reduce the occurrence of bubbles in the screw provided at the stern portion of the hull, so that it is possible to suppress the occurrence of vibration and the reduction in propulsion efficiency.

According to a seventh aspect of the present invention, in the friction resistance reducing device for an air-lubricated ship according to any one of the first to fourth aspects, the low-pressure air may be air taken from the atmosphere. Good.
By comprising in this way, the low pressure air for increasing an air flow rate can be ensured easily.

According to an eighth aspect of the present invention, in the friction resistance reducing device for an air-lubricated ship according to any one of the first to fourth aspects, the low-pressure air compresses air taken from the atmosphere with a blower. It may be a thing.
By comprising in this way, the flow volume of low pressure air, ie, the flow volume of the air supplied to a bubble ejection part, can be increased, ensuring low pressure air easily.

According to a ninth aspect of the present invention, in the fourth aspect, the frictional resistance reducing device for an air-lubricated ship includes a supercharger that compresses and supplies combustion air to a main engine that propels the hull, and the low pressure The air may be air compressed by the supercharger.
Thus, by using the compressed air discharged from the supercharger as the low-pressure air, it is not necessary to provide a separate device for generating the low-pressure air, and the cost can be reduced. In this case, the high-pressure air can be supplied by, for example, a compressor so as to be higher in pressure than the low-pressure air supplied from the supercharger.

According to a tenth aspect of the present invention, in the friction resistance reducing device for an air-lubricated ship, in any one of the first to ninth aspects, the air taken in from the atmosphere is compressed and supplied to the bubble ejection portion. The air pressure raising part may be further provided, and air may be alternatively supplied to at least one of the air pressure raising part and the ejector with respect to the bubble ejection part.
With this configuration, when the draft is shallow, the air boosted by the air boosting unit is supplied to the bubble ejection unit, and when the draft is deep, high pressure air and low pressure air are supplied from the ejector to the bubble ejection unit. can do. Thereby, suitable air can be supplied to a bubble ejection part according to the depth of draft, suppressing energy consumption.

According to an eleventh aspect of the present invention, in the friction resistance reducing device for an air-lubricated ship according to any one of the first to tenth aspects, the high-pressure air is temporarily placed upstream of the ejector. You may further provide the charge tank to store.
By configuring in this way, it is possible to suppress the pulsation of the air flow generated by a device that generates high-pressure air, such as a supercharger or a compressor. Thereby, low pressure air can be smoothly joined with the high pressure air which flows through an ejector. Further, by suppressing the pulsation, it is possible to stably generate bubbles from the bubble ejection portion.

According to a twelfth aspect of the present invention, a ship includes the friction resistance reducing device for an air lubricated ship according to any one of the first to eleventh aspects.
With this configuration, it is possible to improve the propulsive force while saving energy and reducing CO ₂ emissions.

According to the apparatus for reducing frictional resistance of an air-lubricated ship and a ship according to the present invention, it is possible to enhance the energy saving effect and the CO ₂ emission reduction effect.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing an overall configuration of a friction resistance reducing device for an air lubricated ship and a ship according to a first embodiment of the present invention. It is a schematic diagram which shows the frictional resistance reduction apparatus of the air lubrication type ship which concerns on 2nd embodiment of this invention, and the whole structure of a ship. It is a schematic diagram which shows the frictional resistance reduction apparatus of the air lubrication type ship which concerns on 3rd embodiment of this invention, and the whole structure of a ship. It is a schematic diagram which shows the frictional resistance reduction apparatus of the air lubrication type ship which concerns on 4th embodiment of this invention, and the whole structure of a ship. It is a schematic diagram which shows the frictional resistance reduction apparatus of the air lubrication type ship which concerns on 5th embodiment of this invention, and the whole structure of a ship. It is a schematic diagram which shows the frictional resistance reduction apparatus of the air lubrication type ship which concerns on 6th embodiment of this invention, and the whole structure of a ship. It is a schematic diagram which shows the friction resistance reduction apparatus of the air lubrication type ship which concerns on 7th embodiment of this invention, and the whole structure of a ship. It is a schematic diagram which shows the frictional resistance reduction apparatus of the air-lubricated ship which concerns on 8th embodiment of this invention, and the whole structure of a ship. It is a schematic diagram which shows the frictional resistance reduction apparatus of the air lubrication type ship which concerns on 9th embodiment of this invention, and the whole structure of a ship. It is a schematic diagram which shows the frictional resistance reduction apparatus of the air lubrication type ship which concerns on 10th Embodiment of this invention, and the whole structure of a ship. It is a schematic diagram which shows the friction resistance reduction apparatus of the air lubrication type ship which concerns on 11th Embodiment of this invention, and the whole structure of a ship. It is a schematic diagram which shows the frictional resistance reduction apparatus of the air lubrication type ship which concerns on 12th Embodiment of this invention, and the whole structure of a ship.

Hereinafter, a frictional resistance reduction device for an air-lubricated ship and a ship according to an embodiment of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a schematic diagram showing an overall configuration of a frictional resistance reduction device for an air-lubricated ship and a ship according to this embodiment.
As shown in FIG. 1, the ship (air-lubricated ship) 10 of this embodiment mainly includes a hull 11, a screw 12, a main engine 13, a supercharger 14, and a frictional resistance reduction device 20 </ b> A. ing.

The screw 12 is provided to protrude rearward from the bottom of the hull 11 on the stern part 11r side. The screw 12 includes a shaft 12 s, and the shaft 12 s is connected to a main engine 13 provided in the hull 11.

The main machine 13 generates a driving force by burning a mixer in which fuel and air are mixed, and rotationally drives the shaft 12s of the screw 12.
The supercharger 14 takes in air from the outside and compresses it, and sends at least part of it into the main engine 13 as high-pressure combustion air.

The frictional resistance reduction device 20A includes a bubble ejection part 21 and an air supply part 30A.
The bubble jetting portion 21 is provided on the ship bottom 11 b on the bow portion 11 f side of the hull 11. The bubble ejection part 21 is connected via an air supply pipe 22 to an air supply part 30A described later. The bubble ejection unit 21 ejects the air supplied from the air supply unit 30 </ b> A through the air supply pipe 22 provided in the hull 11 from the ship bottom 11 b into the water around the hull 11. Bubbles are generated in the water around the ship bottom 11b by the air jetted from the bubble jetting part 21. The bubbles move relative to the hull 11 as the ship 10 is propelled. More specifically, the generated bubbles move from the bubble ejection portion 21 toward the stern portion 11r in the stern direction along the bottom 11b.

The air supply unit 30A includes an ejector body 31. The ejector body 31 has a tapered flow path 31r having a diameter reduced from the first end portion 31a toward the second end portion 31b. The ejector body 31 has a high-pressure air supply pipe 35 connected to the first end 31a and an air supply pipe 22 connected to the second end 31b.

The suction port 32 is connected to the outer peripheral side surface of the ejector body 31. More specifically, the suction port 32 has a first end 32 a connected to the outside and a second end 32 b connected to the outer peripheral side surface of the ejector body 31. The suction port 32 has a flow path 32r that communicates the first end 32a and the second end 32b of the suction port 32 therein. The flow path 32r is formed in a tapered shape with a diameter decreasing from the first end portion 32a toward the second end portion 32b. The flow path 32r formed inside the suction port 32 is joined and connected to an intermediate portion of the flow path 31r of the ejector body 31 described above. Here, although the case where the flow path 32r is formed in a tapered shape has been described, the flow path 32r may not be tapered.

In this embodiment, the high-pressure air supply pipe 35 is connected to a high-pressure air supply source 37 such as a turbo compressor.
The first end 32 a of the suction port 32 is connected to a low-pressure air supply source 38 that supplies low-pressure air AL that is lower in pressure than the high-pressure air AH generated by the high-pressure air supply source 37. The low-pressure air supply source 38 in this embodiment takes in the atmosphere as the low-pressure air AL and supplies it to the suction port 32. Here, the place which takes in air | atmosphere may be any of an upper deck and the interior space of the hull 11, for example.

A check valve V <b> 1 is provided in the air supply pipe 22 between the ejector body 31 and the bubble ejection part 21 so as to be openable and closable. The check valve V1 allows only the flow from the ejector body 31 side to the bubble ejection part 21 side, and prevents the flow from the bubble ejection part 21 side to the ejector body 31 side.
A switching valve V <b> 2 is provided between the low-pressure air supply source 38 and the ejector body 31. The switching valve V2 opens and closes the flow of low-pressure air between the low-pressure air supply source 38 and the ejector body 31.

Next, the operation of the above-described frictional resistance reduction device 20A will be described.
In order to operate the frictional resistance reduction device 20A, first, the high pressure air supply source 37 is started with the switching valve V2 closed. Then, the high-pressure air AH is sent to the ejector body 31 from the first end portion 31a to the flow path 31r through the high-pressure air supply pipe 35, and the check valve V1 is opened. Thereby, the high pressure air AH is supplied to the bubble ejection part 21 through the check valve V1. Here, the high-pressure air AH sent from the first end 31a flows in the ejector body 31 while flowing in the flow path 31r from the first end 31a toward the second end 31b. As the speed decreases, the flow rate gradually increases. Due to the increase in the flow velocity, the pressure in the flow path 31r is reduced and negative pressure is generated. The negative pressure generated in the flow path 31r extends from the second end 32b of the suction port 32 into the flow path 32r.

Next, after starting the low-pressure air supply source 38, the switching valve V2 is opened. Then, the low-pressure air AL sent out from the low-pressure air supply source 38 flows into the flow path 32r from the first end 32a of the suction port 32 of the ejector body 31. The low-pressure air AL that has flowed into the flow path 32r is drawn into the flow path 31r of the ejector body 31 from the second end portion 32b. The low-pressure air AL drawn into the flow path 31r merges with the high-pressure air AH in the flow path 31r and is sent to the air supply pipe 22 from the second end 31b of the ejector body 31. As a result, the air obtained by adding the low-pressure air AL to the high-pressure air AH is supplied to the bubble ejection portion 21.

Here, in FIG. 1, for convenience of illustration, the whole of the ejector body 31 from the first end 31 a to the second end 31 b is formed in a tapered shape. However, the shape of the ejector main body 31 is not limited to this shape, and may be any shape that can sufficiently increase the flow velocity in the flow path 31r at the location where the second end 32b of the suction port 32 is connected. A diffuser may be provided at the second end 31 b of the ejector body 31 so that the air pressure is recovered within the ejector body 31.

According to the frictional resistance reduction device for an air-lubricated ship of the first embodiment described above and the ship, the high-pressure air AH supplied from the high-pressure air supply source 37 such as a compressor and the low-pressure air supplied from the low-pressure air supply source 38 are used. AL is supplied to the bubble ejection portion 21. Thereby, the air flow rate ejected from the bubble ejection part 21 can be increased. Therefore, even when the draft is deep, a sufficient amount of bubbles can be generated in the water.

Furthermore, compared with the case where only the high-pressure air AH from the high-pressure air supply source 37 is supplied to the bubble ejection part 21, the power of the high-pressure air supply source 37 is increased by the amount that the low-pressure air AL can be merged by the ejector body 31. Can be reduced. That is, an air flow rate equivalent to that when only the high-pressure air supply source 37 is used can be secured with less power.

Furthermore, since the low pressure air AL is drawn in by the negative pressure generated by the flow of the high pressure air AH through the ejector body 31 of the air supply unit 30A and is supplied to the bubble ejection unit 21, the low pressure air AL is joined to the high pressure air AH. Power is not required. That is, it is possible to suppress the frictional resistance force generated between the hull 11 and the water by the air ejected from the bubble ejection portion 21 with less energy consumption.
As a result, the loss to the propulsive force of the hull can be suppressed, the energy saving effect by reducing the fuel consumption, and the CO ₂ emission reduction can be effectively achieved.

(Second embodiment)
Next, a frictional resistance reducing device for an air-lubricated ship and a ship according to a second embodiment of the present invention will be described with reference to the drawings. The second embodiment described below is different from the first embodiment only in the configuration including the air supply unit. For this reason, the same parts as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.
FIG. 2 is a schematic diagram illustrating the overall configuration of the frictional resistance reduction device for an air-lubricated ship and the ship according to this embodiment.
As shown in FIG. 2, the ship 10 in this embodiment includes a frictional resistance reduction device 20B. The frictional resistance reduction device 20 </ b> B includes a bubble ejection unit 21, an air supply unit 30 </ b> A, and a low-pressure air supply unit (air pressurization unit) 40.

The low-pressure air supply unit 40 includes an air introduction pipe 41, a blower 42, and an air supply pipe 43.
The atmosphere introduction pipe 41 has a first end 41a that opens into the atmosphere from the hull 11 above the waterline L, for example, the upper deck. The air introduction pipe 41 has a second end 41 b connected to the blower 42.
The blower 42 pressurizes the atmosphere introduced through the atmosphere introduction pipe 41 and generates low-pressure air AL2 having a pressure lower than that of the high-pressure air AH.
The air supply pipe 43 connects the blower 42 and the bubble ejection part 21. Via this air supply pipe 43, low-pressure air AL <b> 2 whose pressure has been increased by the blower 42 is sent into the bubble ejection portion 21.

A check valve V <b> 1 is provided in the air supply pipe 22 between the ejector body 31 and the bubble ejection part 21 so as to be openable and closable. The check valve V1 allows only the flow from the ejector body 31 side to the bubble ejection part 21 side, and prevents the flow from the bubble ejection part 21 side to the ejector body 31 side.
A switching valve V <b> 2 is provided between the low-pressure air supply source 38 and the ejector body 31. The switching valve V <b> 2 opens and closes a low-pressure air flow path between the low-pressure air supply source 38 and the ejector body 31.
A check valve V3 is provided in the air supply pipe 43 between the blower 42 and the bubble ejection part 21 so as to be openable and closable. The check valve V3 allows only the flow from the blower 42 side to the bubble ejection portion 21 side, and blocks the flow from the bubble ejection portion 21 side to the blower 42 side.

In the frictional resistance reduction device 20B, as in the first embodiment, the high pressure air AH supplied from the high pressure air supply source 37 such as a compressor and the low pressure air supplied from the low pressure air supply source 38 by the air supply unit 30A. After AL is merged in the ejector body 31, it is supplied to the bubble ejection part 21.

The frictional resistance reduction device 20B of this embodiment can perform air supply to the bubble ejection unit 21 by selectively operating the air supply unit 30A and the low-pressure air supply unit 40.
For example, when the draft such as a light draft is shallow, the low pressure air supply unit 40 supplies the low pressure air AL <b> 2 to the bubble ejection unit 21. More specifically, the blower 42 is operated with the switching valve V2 closed. Next, the check valve V <b> 3 is opened, and the low-pressure air AL <b> 2 from the blower 42 is supplied to the bubble ejection part 21.
For example, when the draft such as full draft is deep, the air supply unit 30A supplies the high pressure air AH and the low pressure air AL to the bubble ejection unit 21. More specifically, from the state where the switching valve V2 is closed, the operation of the high pressure air supply source 37, the activation of the low pressure air supply source 38, and the opening operation of the switching valve V2 are sequentially performed in the same manner as in the first embodiment. Thereby, the high pressure air AH and the low pressure air AL are supplied to the bubble ejection part 21.

The frictional resistance reduction device 20B of this embodiment may operate the low-pressure air supply unit 40 and the air supply unit 30A at the same time. By doing in this way, low pressure air AL and low pressure air AL2 can also be supplied to bubble ejection part 21 in addition to high pressure air AH.

According to the second embodiment described above, since the low-pressure air supply unit 40 and the air supply unit 30A are provided, an appropriate amount of air is supplied to the bubble ejection unit 21 while suppressing energy consumption according to draft. Can be supplied.

Further, as in the first embodiment, when air is supplied from the air supply unit 30A, the high pressure air AH supplied from the high pressure air supply source 37 such as a compressor and the low pressure supplied from the low pressure air supply source 38 are used. Air AL is supplied to the bubble ejection part 21. Therefore, the air flow rate ejected from the bubble ejection part 21 can be increased. That is, an air flow rate equivalent to the conventional one can be secured with less power than the conventional one.

Furthermore, if the low-pressure air supply unit 40 and the air supply unit 30A are operated simultaneously, the low-pressure air AL and the low-pressure air AL2 can be supplied to the bubble ejection unit 21 in addition to the high-pressure air AH. Thereby, the air flow rate supplied to the bubble ejection part 21 can further be increased.

In this way, by reducing the frictional resistance force generated between the hull 11 and the water by the air ejected from the bubble ejection portion 21 with less energy consumption, the loss to the propulsive force of the hull is suppressed, and the fuel consumption is reduced. It is possible to effectively improve the energy saving effect and reduce CO ₂ emissions.

(Third embodiment)
Next, a frictional resistance reducing device for an air lubricated ship according to a third embodiment of the present invention and the ship will be described with reference to the drawings. In the third embodiment, the same portions as those in the first embodiment and the second embodiment are denoted by the same reference numerals, and redundant description is omitted.
FIG. 3 is a schematic diagram showing an overall configuration of the frictional resistance reduction device for an air-lubricated ship and the ship according to this embodiment.
As shown in FIG. 3, the ship 10 in this embodiment includes a frictional resistance reduction device 20C. The frictional resistance reduction device 20 </ b> C includes a bubble ejection unit 21, an air supply unit 30 </ b> C, and a low-pressure air supply unit 40.

The air supply unit 30 </ b> C includes an ejector body 31. A suction port 32 is connected to the outer peripheral side surface of the ejector body 31.
The ejector body 31 has a high-pressure air supply pipe 35 connected to the first end 31a, and an air supply pipe 22 connected to the second end 31b.

The high-pressure air supply pipe 35 in this embodiment is branched and connected to the discharge side of the supercharger (high-pressure air supply source, auxiliary machine) 14. The high-pressure air supply pipe 35 sends a part of the compressed air discharged from the supercharger 14 to the first end 31a of the ejector body 31 as high-pressure air AH.

A low-pressure air supply pipe 39 is connected to the first end 32 a of the suction port 32. The low-pressure air supply pipe 39 in this embodiment opens into the atmosphere above the draft line L in the hull 11 and sends the atmosphere to the inlet 32 as the low-pressure air AL.

A check valve V <b> 1 is provided in the air supply pipe 22 between the ejector body 31 and the bubble ejection part 21 so as to be openable and closable.
A switching valve V2 is provided in the low-pressure air supply pipe 39 for taking in the atmosphere so that it can be opened and closed. The switching valve V2 interrupts the flow of low-pressure air from the low-pressure air supply pipe 39 to the ejector body 31.
A check valve V3 is provided in the air supply pipe 43 between the blower 42 and the bubble ejection part 21 so as to be openable and closable.
Further, a switching valve V4 is provided in the high-pressure air supply pipe 35 that takes in the high-pressure air AH from the supercharger 14 so that it can be opened and closed. The switching valve V4 can perform intermittent flow of the high-pressure air AH from the high-pressure air supply pipe 35 to the ejector body 31 and adjust the flow rate thereof.

In such a flow path 31r of the ejector body 31 of the air supply unit 30C, when the switching valve V4 is opened from the state where the switching valves V2 and V4 are closed, the air is compressed by the supercharger 14 through the high-pressure air supply pipe 35. High-pressure air AH is sent from the first end portion 31a. Next, the check valve V1 is opened. Thereby, the high-pressure air AH is supplied from the ejector body 31 to the bubble jetting part 21 through the check valve V1. Here, the flow rate of the high-pressure air AH sent from the first end portion 31a gradually increases in the ejector body 31, and a negative pressure is generated in the flow path 31r.

Next, when the switching valve V <b> 2 is opened, the low-pressure air AL composed of the atmosphere taken in from the low-pressure air supply pipe 39 is discharged from the first end 32 a of the suction port 32 into the flow path 32 r due to the negative pressure in the ejector body 31. Flow into.
The low-pressure air AL that has flowed into the flow path 32r is drawn into the flow path 31r of the ejector body 31 from the second end portion 32b. The low-pressure air AL drawn into the flow path 31r merges with the high-pressure air AH in the flow path 31r and is sent to the air supply pipe 22 from the second end 31b of the ejector body 31. Thereby, air obtained by adding the low-pressure air AL to the high-pressure air AH is supplied to the bubble ejection portion 21.

The frictional resistance reduction device 20C can supply air to the bubble ejection unit 21 by selectively operating the air supply unit 30C and the low-pressure air supply unit 40 as in the second embodiment. In this way, for example, when the draft such as a light draft is shallow, the low pressure air supply unit 40 supplies the low pressure air AL2 to the bubble ejection unit 21. More specifically, the blower 42 is operated with the switching valves V2 and V4 closed. Next, the check valve V3 is opened. As a result, the low-pressure air AL <b> 2 is supplied to the bubble ejection part 21.

For example, when the draft such as a full draft is deep, the high pressure air AH and the low pressure air AL are supplied to the bubble ejection part 21 by the air supply part 30A. More specifically, from the state in which the switching valves V2 and V4 are closed, the opening operation of the switching valve V4 and the opening operation of the switching valve V2 are sequentially performed in the same manner as in the third embodiment. Thereby, the high pressure air AH and the low pressure air AL are supplied to the bubble ejection part 21.

Furthermore, the low-pressure air supply unit 40 and the air supply unit 30C can be operated simultaneously to supply the low-pressure air AL2 and the low-pressure air AL2 to the bubble ejection unit 21 in addition to the high-pressure air AH.

According to the third embodiment described above, since a part of the compressed air discharged from the supercharger 14 is used as the high-pressure air AH, it is not necessary to prepare a compressor or the like in order to obtain the high-pressure air AH. Compared with the embodiment, the number of parts can be suppressed.

In the third embodiment, a part of the compressed air discharged from the supercharger 14 is used as the high-pressure air AH. For example, the exhaust gas from the main engine 13 that propels the hull 11 of the ship 10 is high-pressure. It can also be sent to the ejector body 31 as air AH. In this case, as shown in FIG. 3, instead of the high-pressure air supply pipe 35, an exhaust gas supply pipe 35G for sending the exhaust gas from the main machine 13 to the ejector body 31 is provided (hereinafter, the same applies to the fourth to sixth embodiments). ). The exhaust gas supply pipe 35G is provided with a switching valve V4 'that can be opened and closed. The switching valve V4 'can perform intermittent flow of the high-pressure air AH from the exhaust gas supply pipe 35G to the ejector body 31 and adjust the flow rate thereof.

(Fourth embodiment)
Next, an air-lubricated ship frictional resistance reducing device and ship according to a fourth embodiment of the present invention will be described with reference to the drawings. In the fourth embodiment, the same parts as those in the first to third embodiments are denoted by the same reference numerals, and redundant description is omitted.
FIG. 4 is a schematic diagram showing the overall configuration of the frictional resistance reduction device for an air-lubricated ship and the ship according to this embodiment.
As shown in FIG. 4, the ship 10 in this embodiment includes a frictional resistance reduction device 20D. The frictional resistance reduction device 20D includes a bubble ejection part 21 and an air supply part 30D.

The air supply unit 30D includes an ejector body 31. Further, the ejector body 31 is connected with an inlet 32 on the outer peripheral side surface thereof.

The ejector body 31 has a tapered flow path 31r as in the above-described embodiments. A high-pressure air supply pipe 35 is connected to the first end 31a of the ejector body 31, and an air supply pipe 22 is connected to the second end 31b. The high pressure air supply pipe 35 in this embodiment is connected to the discharge side of the supercharger 14 as in the third embodiment, and a part of the compressed air discharged from the supercharger 14 is used as the high pressure air AH as the ejector body. 31 is fed into the first end 31a.

A low-pressure air supply pipe 39 is connected to the first end 32 a of the suction port 32. The low pressure air supply pipe 39 in this embodiment is connected to the blower 42. The blower 42 sucks and pressurizes the atmosphere introduced through the atmosphere introduction pipe 41 to generate low-pressure air AL having a pressure lower than that of the high-pressure air AH. The low-pressure air AL is introduced into the suction port 32 via the low-pressure air supply pipe 39.

A check valve V <b> 1 is provided in the air supply pipe 22 between the ejector body 31 and the bubble ejection part 21 so as to be openable and closable.
In the low-pressure air supply pipe 39, a switching valve V2 is provided between the blower 42 and the ejector body 31 so as to be opened and closed. The switching valve V2 interrupts the flow of low-pressure air from the low-pressure air supply pipe 39 to the ejector body 31.

In the high-pressure air supply pipe 35 that takes in the high-pressure air AH from the supercharger 14, a switching valve V4 is provided so that it can be opened and closed. The switching valve V4 intermittently flows the high-pressure air AH from the high-pressure air supply pipe 35 to the ejector body 31 and adjusts the flow rate thereof.

In the air supply unit 30D, when the switching valve V4 is opened after the switching valves V2 and V4 are closed, the high-pressure air AH compressed by the supercharger 14 through the high-pressure air supply pipe 35 is ejected from the first end 31a. It is sent to 31. Next, the check valve V1 is opened. Thereby, the high-pressure air AH is supplied from the ejector body 31 to the bubble jetting part 21 through the check valve V1. Here, the flow velocity of the high-pressure air AH sent from the first end portion 31a of the ejector body 31 gradually increases in the ejector body 31, and a negative pressure is generated in the flow path 31r.
Next, after operating the blower 42, the low-pressure air AL is sent to the suction port 32 by opening the switching valve V <b> 2. Then, the low pressure air AL introduced into the suction port 32 is drawn into the ejector body 31 due to the negative pressure in the ejector body 31. The low-pressure air AL drawn into the flow path 31r merges with the high-pressure air AH in the flow path 31r and is sent to the air supply pipe 22 from the second end 31b of the ejector body 31. As a result, the air obtained by adding the low-pressure air AL to the high-pressure air AH is supplied to the bubble ejection portion 21.

According to the fourth embodiment described above, the high-pressure air AH compressed by the supercharger 14 and the low-pressure air AL pressurized by the blower 42 are supplied to the bubble jetting unit 21. Thereby, the air flow rate ejected from the bubble ejection part 21 can be increased. In particular, in the case of the fourth embodiment, the flow rate of the low-pressure air AL can be increased as compared with the case where the atmosphere is directly taken in as the low-pressure air AL.

(Fifth embodiment)
Next, a frictional resistance reducing device for an air lubricated ship and a ship according to a fifth embodiment of the present invention will be described with reference to the drawings. In the fifth embodiment, the same parts as those in the first to fourth embodiments are denoted by the same reference numerals, and redundant description is omitted.
FIG. 5 is a schematic view showing the overall configuration of the friction resistance reducing device for an air lubricated ship and the ship according to this embodiment.
As shown in FIG. 5, the ship 10 in this embodiment includes a frictional resistance reduction device 20E. The frictional resistance reduction device 20E includes a bubble ejection unit 21, a bubble recovery unit 25, an air supply unit 30E, and a low-pressure air supply unit 40.

The bubble recovery unit 25 recovers the bubbles generated by the bubble ejection unit 21. The bubble recovery unit 25 is provided on the bottom 11b of the hull 11 so as to open downward. The bubble recovery unit 25 is arranged on the bow portion 11f side of the screw 12 in the bow-stern direction, and on the stern portion 11r side as much as possible.

The air supply unit 30E includes an ejector body 31. A suction port 32 is connected to the outer peripheral side surface of the ejector body 31.
The ejector body 31 has a tapered flow path 31r as in the above-described embodiments. The ejector body 31 has a high-pressure air supply pipe 35 connected to the first end 31a, and an air supply pipe 22 connected to the second end 31b.
The high pressure air supply pipe 35 in this embodiment is connected to the discharge side of the supercharger 14. A part of the compressed air discharged from the supercharger 14 is sent to the first end 31a of the ejector body 31 as high-pressure air AH.

A low-pressure air supply pipe 39 is connected to the first end 32 a of the suction port 32. The low-pressure air supply pipe 39 in this embodiment is connected to the bubble recovery unit 25, and air obtained from the bubbles recovered by the bubble recovery unit 25 is sent to the suction port 32 as low-pressure air AL.

A check valve V <b> 1 is provided in the air supply pipe 22 between the ejector body 31 and the bubble ejection part 21 so as to be openable and closable.
A check valve V3 is provided in the air supply pipe 43 between the blower 42 and the bubble ejection part 21 so as to be openable and closable.

In the high-pressure air supply pipe 35 that takes in the high-pressure air AH from the supercharger 14, a switching valve V4 is provided so that it can be opened and closed. The switching valve V4 intermittently flows the high-pressure air AH from the high-pressure air supply pipe 35 to the ejector body 31 and adjusts the flow rate thereof.

A check valve V5 is provided in the low-pressure air supply pipe 39 that takes in air obtained from the bubbles recovered by the bubble recovery unit 25 as low-pressure air AL. The check valve V5 allows only the flow from the bubble recovery unit 25 to the suction port 32 and prevents the flow from the suction port 32 to the bubble recovery unit 25. The check valve V <b> 5 has a function of adjusting the flow rate from the bubble recovery unit 25 to the suction port 32. Here, in this embodiment, the case where the check valve V5 has a flow rate adjusting function is illustrated, but the check valve and the flow rate adjusting valve may be connected in series.

In the air supply unit 30E, the switching valve V4 is opened from the state where the switching valve V4 and the check valve V5 are closed. Then, the high pressure air AH compressed by the supercharger 14 is sent into the ejector body 31 from the first end portion 31 a through the high pressure air supply pipe 35. Next, the check valve V1 is opened. Thereby, the high-pressure air AH is supplied from the ejector body 31 to the bubble jetting part 21 through the check valve V1. The flow rate of the high-pressure air AH gradually increases in the ejector body 31, and a negative pressure is generated in the flow path 31r.
Next, the check valve V5 is opened. Then, the low-pressure air AL, which is the air recovered by the bubble recovery unit 25, flows from the first end portion 32a of the suction port 32 by the flow rate adjusted by the flow rate adjustable check valve V5. The low-pressure air AL that has flowed into the flow path 32r is drawn into the flow path 31r of the ejector body 31 from the second end 32b, merges with the high-pressure air AH in the flow path 31r, and the second end of the ejector body 31. It is fed into the air supply pipe 22 from the portion 31b. Thereby, low-pressure air AL is supplied to the bubble jetting part 21 in addition to the high-pressure air AH.

In such a frictional resistance reduction device 20E, the air supply unit 30E and the low-pressure air supply unit 40 can be selectively operated to supply air to the bubble ejection unit 21.
Thus, for example, when the draft is shallow, the low-pressure air supply unit 40 supplies the low-pressure air AL2 to the bubble ejection unit 21, and when the draft is deep, the air supply unit 30E supplies the high-pressure air AH and the low-pressure air AL. It can supply to the bubble ejection part 21.
Further, the low-pressure air supply unit 40 and the air supply unit 30E can be operated simultaneously to supply the low-pressure air AL2 and the low-pressure air AL2 to the bubble jetting unit 21 in addition to the high-pressure air AH.

According to the fifth embodiment described above, since the low-pressure air supply unit 40 and the air supply unit 30E are provided, an appropriate amount of air is supplied to the bubble ejection unit 21 while suppressing energy consumption according to draft. Can be supplied.

When air is supplied from the air supply unit 30E, high-pressure air AH compressed by the supercharger 14 and low-pressure air AL obtained from the bubbles recovered by the bubble recovery unit 25 are supplied to the bubble ejection unit 21. The Therefore, the air flow rate ejected from the bubble ejection part 21 can be increased.

Furthermore, if the low-pressure air supply unit 40 and the air supply unit 30E are operated simultaneously, the low-pressure air AL and the low-pressure air AL2 can be supplied to the bubble ejection unit 21 in addition to the high-pressure air AH. Thereby, the air flow rate supplied to the bubble ejection part 21 can further be increased.

Since a part of the compressed air discharged from the supercharger 14 is used as the high-pressure air AH, it is not necessary to prepare a compressor or the like to obtain the high-pressure air AH, and the above effects can be obtained at a low cost.

Particularly in the fifth embodiment, since the low-pressure air AL is obtained from the bubbles recovered by the bubble recovery unit 25, it is advantageous in that no energy or cost is required.
Furthermore, by collecting the low-pressure air AL with the bubble recovery unit 25, it is possible to suppress the bubbles from hitting the screw 12 provided at the stern portion 11r of the hull 11, and to suppress the occurrence of vibrations and the reduction in propulsion efficiency.

(Sixth embodiment)
Next, an air-lubricated ship frictional resistance reducing device and ship according to a sixth embodiment of the present invention will be described with reference to the drawings. In the sixth embodiment, the same parts as those in the first to fifth embodiments are denoted by the same reference numerals, and redundant description is omitted.
FIG. 6 is a schematic diagram showing an overall configuration of the friction resistance reducing device for an air-lubricated ship and the ship according to this embodiment.
As shown in FIG. 6, the ship 10 in this embodiment includes a frictional resistance reduction device 20F. The frictional resistance reduction device 20F includes a bubble ejection unit 21, a bubble recovery unit 25, and an air supply unit 30F.

The air supply unit 30 </ b> F includes an ejector main body 31. A suction port 32 is connected to the outer peripheral side surface of the ejector body 31.
The ejector body 31 has a tapered flow path 31r as in the above-described embodiments. The ejector body 31 has a high-pressure air supply pipe 35 connected to the first end 31a, and an air supply pipe 22 connected to the second end 31b.

In this embodiment, the high-pressure air supply pipe 35 is connected to the discharge side of the supercharger 14. A part of the compressed air discharged from the supercharger 14 is sent to the first end 31a of the ejector body 31 as high-pressure air AH.

A low-pressure air supply pipe 39 is connected to the first end 32 a of the suction port 32. The low-pressure air supply pipe 39 in this embodiment is bifurcated by a branch pipe 39a and a branch pipe 39b. The branch pipe 39 a is connected to the bubble recovery unit 25, and the branch pipe 39 b is connected to the blower 62. The blower 62 pressurizes the atmosphere introduced through the atmosphere introduction pipe 61. That is, the low-pressure air supply pipe 39 supplies the air obtained from the bubbles recovered by the bubble recovery unit 25 and the atmosphere pressurized by the blower 62 to the suction port 32 as the low-pressure air AL. The supply amount of the low-pressure air AL by the blower 62 can be appropriately changed according to the flow rate of the recovered air recovered from the bubble recovery unit 25.

A check valve V <b> 1 is provided in the air supply pipe 22 between the ejector body 31 and the bubble ejection part 21 so as to be openable and closable.
A check valve V3 is provided in the air supply pipe 43 between the blower 42 and the bubble ejection part 21 so as to be openable and closable.

In the high-pressure air supply pipe 35 that takes in the high-pressure air AH from the supercharger 14, a switching valve V4 is provided so that it can be opened and closed. The switching valve V4 intermittently flows the high-pressure air AH from the high-pressure air supply pipe 35 to the ejector body 31 and adjusts the flow rate thereof.

The branch pipe 39a of the low-pressure air supply pipe 39 that takes in air obtained from the bubbles collected by the bubble collection unit 25 as low-pressure air AL is provided with a check valve V5 that can adjust the flow rate, as in the fifth embodiment. ing. The branch pipe 39b is provided with a switching valve V6 that interrupts the flow of air fed from the blower 62.

In the air supply unit 30F, when the switching valve V4 is opened from the state where the switching valves V4, V6 and the check valve V5 are closed, the high pressure air AH compressed by the supercharger 14 through the high pressure air supply pipe 35 is the first end. It is sent from the part 31a to the ejector body 31. Next, the check valve V1 is opened. Thereby, the high-pressure air AH is supplied from the ejector body 31 to the bubble jetting part 21 through the check valve V1. Here, the high-pressure air AH sent from the first end portion 31a of the ejector body 31 gradually increases in flow velocity in the ejector body 31 and a negative pressure is generated in the flow path 31r.
Next, when the check valve V5 is opened, the low pressure air AL that is the air recovered by the bubble recovery unit 25 flows from the first end 32a of the suction port 32 due to the negative pressure in the ejector body 31. Furthermore, after operating the blower 62, the switching valve V6 is opened, whereby the low-pressure air AL is sent into the suction port 32. As a result, the air recovered by the bubble recovery unit 25 and the low-pressure air AL that is the atmosphere pressurized by the blower 62 flow into the ejector body 31. The low-pressure air AL that has flowed into the flow path 32r is drawn into the flow path 31r of the ejector body 31 from the second end 32b, merges with the high-pressure air AH in the flow path 31r, and the second end of the ejector body 31. It is fed into the air supply pipe 22 from the portion 31b. Thereby, air obtained by adding the low-pressure air AL to the high-pressure air AH is supplied to the bubble ejection portion 21.

According to the sixth embodiment described above, in the air supply unit 30F, the low pressure obtained from the high pressure air AH compressed by the supercharger 14, the air recovered by the bubble recovery unit 25, and the atmosphere pressurized by the blower 62. The air AL merges and is supplied to the bubble ejection part 21. Therefore, the air flow rate ejected from the bubble ejection part 21 can be increased. In particular, in the sixth embodiment, since the air obtained from the bubbles recovered by the bubble recovery unit 25 is used as part of the low-pressure air AL, no energy or cost is required. Furthermore, since the air pressurized by the blower 62 is used as the low pressure air AL, the flow rate of the low pressure air AL is increased when the flow rate of the low pressure air AL obtained from the bubbles recovered from the bubble recovery unit 25 is insufficient. Can do.

(Seventh embodiment)
Next, an air-lubricated ship frictional resistance reducing device and ship according to a seventh embodiment of the present invention will be described with reference to the drawings. In the seventh embodiment, the same parts as those in the first to sixth embodiments are denoted by the same reference numerals, and redundant description is omitted.
FIG. 7 is a schematic diagram showing the overall configuration of the frictional resistance reduction device for an air-lubricated ship and the ship according to this embodiment.
As shown in FIG. 7, the ship 10 in this embodiment includes a frictional resistance reduction device 20G. The frictional resistance reduction device 20G includes a bubble ejection part 21 and an air supply part 30G.

The air supply unit 30G includes an ejector body 31. A suction port 32 is connected to the outer peripheral side surface of the ejector body 31.
The ejector body 31 has a tapered flow path 31r as in the above-described embodiments. The ejector body 31 is connected to a high-pressure air supply pipe 35 at a first end 31a, and an air supply pipe 22 is connected to a second end 31b.
In this embodiment, the high-pressure air supply pipe 35 is connected to a high-pressure air supply source 37 such as a turbo compressor.

A low-pressure air supply pipe 39 is connected to the first end 32 a of the suction port 32. The low-pressure air supply pipe 39 in this embodiment is open to the atmosphere above the water line L in the hull 11 and sends the atmosphere to the suction port 32 as low-pressure air AL.

A check valve V <b> 1 is provided in the air supply pipe 22 between the ejector body 31 and the bubble ejection part 21 so as to be openable and closable.
The low-pressure air supply pipe 39 is provided with a switching valve V2 that can be opened and closed. The switching valve V2 interrupts the flow of low-pressure air from the low-pressure air supply pipe 39 to the ejector body 31.

In the air supply unit 30G, the high pressure air supply source 37 is activated with the switching valve V2 closed. Then, high-pressure air AH is fed into the ejector body 31 from the first end portion 31a to the flow path 31r through the high-pressure air supply pipe 35. Next, the check valve V1 is opened. Thereby, the high pressure air AH is supplied to the bubble ejection part 21 through the check valve V1. The high-pressure air AH sent from the first end portion 31a of the ejector body 31 has a gradually increasing flow velocity in the ejector body 31 and a negative pressure is generated in the flow path 31r.

Next, the switching valve V2 is opened. Then, the low pressure air AL made of the atmosphere taken in from the low pressure air supply pipe 39 flows into the flow path 32r from the first end portion 32a of the suction port 32 due to the negative pressure in the ejector body 31. The low-pressure air AL that has flowed into the flow path 32r is drawn into the flow path 31r of the ejector body 31 from the second end 32b, and merges with the high-pressure air AH within the flow path 31r. The air merged in the flow path 31r is fed into the air supply pipe 22 from the second end 31b of the ejector body 31. Thereby, air obtained by adding the low-pressure air AL to the high-pressure air AH is supplied to the bubble ejection portion 21.

According to the seventh embodiment described above, in the air supply unit 30G, the high-pressure air AH compressed by the high-pressure air supply source 37 such as a turbo compressor and the low-pressure air AL that is the atmosphere are supplied to the bubble ejection unit 21. The Therefore, the air flow rate ejected from the bubble ejection part 21 can be increased.
In this way, by reducing the frictional resistance force generated between the hull 11 and the water by the air ejected from the bubble ejection portion 21 with less energy consumption, the loss to the propulsive force of the hull is suppressed, and the fuel consumption is reduced. It is possible to effectively improve the energy saving effect and reduce CO ₂ emissions.

In such a configuration, the air supply unit 30G is disposed on the bow portion 11f side of the hull 11, and piping for connecting to the supercharger 14 and the like on the stern portion 11r side is unnecessary. As a result, the equipment configuration is simplified and the cost can be reduced.

(Eighth embodiment)
Next, a frictional resistance reducing device for an air lubricated ship according to an eighth embodiment of the present invention, the ship will be described with reference to the drawings. In the eighth embodiment, the same portions as those in the first to seventh embodiments are denoted by the same reference numerals, and redundant description is omitted.
FIG. 8 is a schematic diagram showing an overall configuration of the friction resistance reducing device for an air-lubricated ship and the ship according to this embodiment.
As shown in FIG. 8, the ship 10 in this embodiment includes a frictional resistance reducing device 20H. The frictional resistance reduction device 20H includes a bubble ejection unit 21, a bubble recovery unit 25, and an air supply unit 30H.

The air supply unit 30H includes an ejector body 31. A suction port 32 is connected to the outer peripheral side surface of the ejector body 31. The ejector body 31 has a tapered flow path 31r as in the above-described embodiments. The ejector body 31 has a high-pressure air supply pipe 35 connected to the first end 31a and an air supply pipe 22 connected to the second end 31b. The high-pressure air supply pipe 35 in this embodiment is connected to a high-pressure air supply source 37 such as a turbo compressor.

A low-pressure air supply pipe 39 is connected to the first end 32 a of the suction port 32. The low-pressure air supply pipe 39 in this embodiment is connected to the bubble recovery unit 25, and air obtained from the bubbles recovered by the bubble recovery unit 25 is taken into the suction port 32 as low-pressure air AL.

A check valve V <b> 1 is provided in the air supply pipe 22 between the ejector body 31 and the bubble ejection part 21 so as to be openable and closable.
A check valve V5 is provided in the low-pressure air supply pipe 39 that takes in air obtained from the bubbles recovered by the bubble recovery unit 25 as low-pressure air AL.

In the air supply unit 30H, the high pressure air supply source 37 is activated from the state where the check valve V1 and the check valve V5 are closed. As a result, the high-pressure air AH is fed into the ejector body 31 from the first end 31a to the flow path 31r through the high-pressure air supply pipe 35. Next, the check valve V1 is opened. Thereby, the high pressure air AH is supplied to the bubble ejection part 21 through the check valve V1. The high-pressure air AH sent from the first end portion 31a of the ejector body 31 has a gradually increasing flow velocity in the ejector body 31 and a negative pressure is generated in the flow path 31r.

Next, check valve V5 is opened. Then, low-pressure air AL that is air recovered by the bubble recovery unit 25 flows from the first end portion 32 a of the suction port 32. As a result, low-pressure air AL that is air collected by the bubble collection unit 25 flows into the ejector body 31 from the first end 32 a of the suction port 32. The low-pressure air AL that has flowed into the flow path 32r is drawn into the flow path 31r of the ejector body 31 from the second end 32b, merges with the high-pressure air AH in the flow path 31r, and the second end of the ejector body 31. It is fed into the air supply pipe 22 from the portion 31b. Thereby, air obtained by adding the low-pressure air AL to the high-pressure air AH is supplied to the bubble ejection portion 21.

According to the eighth embodiment described above, in the air supply unit 30H, the high-pressure air AH compressed by the high-pressure air supply source 37 such as a turbo compressor and the low-pressure air AL recovered by the bubble recovery unit 25 merge, It is supplied to the bubble ejection part 21. Therefore, the air flow rate ejected from the bubble ejection part 21 can be increased. Similarly to the sixth embodiment, since the low-pressure air AL is obtained from the bubbles recovered by the bubble recovery unit 25, no energy or cost is required. Since the low-pressure air AL is recovered from below the ship bottom 11b, the pressure is higher than the atmosphere in the seventh embodiment, and the energy efficiency can be further increased compared to the case where the atmosphere is pressurized.

(Ninth embodiment)
Next, an air-lubricated ship frictional resistance reducing device and ship according to a ninth embodiment of the present invention will be described with reference to the drawings. In the ninth embodiment, the same portions as those in the first to eighth embodiments are denoted by the same reference numerals, and redundant description is omitted.
FIG. 9 is a schematic diagram showing the overall configuration of the friction resistance reducing device for an air lubricated ship and the ship according to this embodiment.
As shown in FIG. 9, the ship 10 in this embodiment includes a frictional resistance reducing device 20J. The frictional resistance reduction device 20J includes a bubble ejection part 21 and an air supply part 30J.

The air supply unit 30J includes an ejector body 31. A suction port 32 is connected to the outer peripheral side surface of the ejector body 31. The ejector body 31 has a tapered flow path 31r as in the above-described embodiments. The ejector body 31 has a high-pressure air supply pipe 35 connected to the first end 31a and an air supply pipe 22 connected to the second end 31b. The high-pressure air supply pipe 35 in this embodiment is connected to a high-pressure air supply source 37 such as a turbo compressor.

A low-pressure air supply pipe 39 is connected to the first end 32 a of the suction port 32. The low-pressure air supply pipe 39 in this embodiment is connected to the discharge side of the supercharger 14, and a part of the compressed air discharged from the supercharger 14 is low-pressure on the first end 31a of the ejector body 31. It is sent as air AL. This embodiment assumes the case where the output of the main machine 13 is small. Since the compressed air discharged from the supercharger 14 of this embodiment is lower in pressure than the high-pressure air AH compressed by the high-pressure air supply source 37 such as a compressor, it can be used as the low-pressure air AL.

A check valve V <b> 1 is provided in the air supply pipe 22 between the ejector body 31 and the bubble ejection part 21 so as to be openable and closable.
A switching valve V4 is provided in the low-pressure air supply pipe 39 that takes in the low-pressure air AL from the supercharger 14 so that it can be opened and closed. The switching valve V4 intermittently flows the low-pressure air AL from the low-pressure air supply pipe 39 to the ejector body 31 and adjusts the flow rate thereof.

In the air supply unit 30J, the high pressure air supply source 37 is operated with the switching valve V4 closed. Then, the high pressure air AH is sent from the high pressure air supply source 37 to the first end portion 31 a of the ejector body 31. Next, the check valve V1 is opened. The flow rate of the high-pressure air AH gradually increases in the ejector body 31, and a negative pressure is generated in the flow path 31r.
Next, the switching valve V4 is opened. Then, the low-pressure air AL sent out from the supercharger 14 flows from the first end portion 32 a of the suction port 32 due to the negative pressure in the ejector body 31. The low-pressure air AL that has flowed into the flow path 32r is drawn into the flow path 31r of the ejector body 31 from the second end 32b, merges with the high-pressure air AH in the flow path 31r, and the second end of the ejector body 31. It is fed into the air supply pipe 22 from the portion 31b. Thereby, air obtained by adding the low-pressure air AL to the high-pressure air AH is supplied to the bubble ejection portion 21.

According to the above-described ninth embodiment, the high-pressure air AH compressed by the high-pressure air supply source 37 such as a compressor and the low-pressure air AL compressed by the supercharger 14 are merged and supplied to the bubble ejection unit 21. Is done. Therefore, the air flow rate ejected from the bubble ejection part 21 can be increased. In particular, since the low-pressure air AL uses a part of the compressed air discharged from the supercharger 14, the flow rate of the air ejected from the bubble ejection part 21 can be further increased.

(Tenth embodiment)
Next, an air-lubricated ship frictional resistance reducing device and ship according to a tenth embodiment of the present invention will be described with reference to the drawings. In the tenth embodiment, the same portions as those in the first to ninth embodiments are denoted by the same reference numerals, and redundant description is omitted.
FIG. 10 is a schematic diagram showing an overall configuration of the friction resistance reducing device for an air-lubricated ship and the ship according to this embodiment.
As shown in FIG. 10, the ship 10 in this embodiment includes a frictional resistance reducing device 20K. The frictional resistance reduction device 20K includes a bubble ejection unit 21, a bubble recovery unit 25, an air supply unit 30K, and a low-pressure air supply unit 40.

The air supply unit 30K in this embodiment includes two ejector bodies 31 in series. These ejector main bodies 31 have tapered flow paths 31r as in the above-described embodiments. Of the ejector main bodies 31 connected in series, a high pressure air supply pipe 35 is connected to the first end portion 31a of the ejector main body 31A arranged on the upstream side. A connection pipe 49 is connected to the second end 31b of the ejector body 31A arranged on the upstream side. The first end portion 31 a of the downstream ejector body 31 </ b> B is connected to the upstream ejector body 31 </ b> A via a connection pipe 49. An air supply pipe 22 is connected to the second end 31b of the ejector body 31B on the downstream side.

The high-pressure air supply pipe 35 in this embodiment is connected to the discharge side of the supercharger 14, and a part of the compressed air discharged from the supercharger 14 is the high-pressure air AH of the upstream ejector body 31. It is fed into the first end portion 31a.

A low-pressure air supply pipe 39 branched in the middle is connected to the first end portion 32a of the suction port 32 provided in the ejector main bodies 31A and 31B. The low-pressure air supply pipe 39 in this embodiment is connected to the bubble recovery unit 25. The low-pressure air supply pipe 39 distributes air obtained from the bubbles recovered by the bubble recovery unit 25 to the respective suction ports 32 as low-pressure air AL.

A check valve V <b> 1 is provided in the air supply pipe 22 between the ejector body 31 and the bubble ejection part 21 so as to be openable and closable.
A check valve V3 is provided in the air supply pipe 43 between the blower 42 and the bubble ejection part 21 so as to be openable and closable.
In the high-pressure air supply pipe 35 that takes in the high-pressure air AH from the supercharger 14, a switching valve V4 is provided so as to be openable and closable. The switching valve V4 intermittently flows the high-pressure air AH from the high-pressure air supply pipe 35 to the ejector body 31 and adjusts the flow rate thereof.
A check valve V51 is provided in the low-pressure air supply pipe 39 that takes in air obtained from the bubbles recovered by the bubble recovery unit 25 as low-pressure air AL.
A switching valve V7 is provided in the low-pressure air supply pipe 39 branched to the ejector body 31A on the upstream side. By opening the switching valve V7, the low pressure air AL can be diverted toward the ejector body 31A and the ejector body 31B. By closing the switching valve V7, the low pressure air AL can be supplied only to the ejector body 31B.

In the air supply unit 30K, when the switching valve V4 is opened after the switching valve V4, the switching valve V7, and the check valve V51 are closed, the high-pressure air AH compressed by the supercharger 14 through the high-pressure air supply pipe 35 is first. It is sent from the one end 31a to the upstream ejector body 31A. Next, the check valve V1 is opened. Thereby, the high pressure air AH is supplied to the bubble ejection part 21 through the check valve V1 from the ejector main bodies 31A connected in series and the ejector main bodies 31 of the ejector main bodies 31B.

The high-pressure air AH sent into the flow path 31r of the upstream ejector body 31A gradually increases in flow velocity in the ejector body 31A, and negative pressure is generated in the flow path 31r. The high-pressure air AH sent out from the upstream ejector body 31A is sent into the downstream ejector body 31B via the connecting pipe 49. The high-pressure air AH sent into the flow path 31r of the ejector body 31B gradually increases in flow velocity in the ejector body 31B, and a negative pressure is generated in the flow path 31r.

Next, the check valve V51 is opened. Then, due to the negative pressure in the ejector body 31 of the ejector body 31B, the low pressure air AL that is the air collected by the bubble collection unit 25 flows from the first end 32a of the suction port 32 of the ejector body 31B.
Further, when the switching valve V7 is opened, the low-pressure air AL is also sent to the suction port 32 of the upstream ejector body 31A through the low-pressure air supply pipe 39 branched toward the upstream ejector body 31A. As a result, the low-pressure air AL that has flowed into the flow path 32r of the upstream ejector body 31A is drawn into the flow path 31r of the ejector body 31A, and merges with the high-pressure air AH within the flow path 31r. It is sent out from the second end 31b of the main body 31A.
The low-pressure air AL that has flowed into the flow path 32r of the suction port 32 of the ejector body 31B is drawn into the flow path 31r of the ejector body 31B, and merges with air (AH + AL) in the flow path 31r. AH + AL + AL) is sent out from the second end 31b of the ejector body 31B on the downstream side.

In such a frictional resistance reduction device 20K, the air supply unit 30K and the low-pressure air supply unit 40 can be selectively operated to supply air to the bubble ejection unit 21.
Thereby, for example, when the draft is shallow, the low pressure air supply unit is operated by opening the check valve V3 by operating the blower 42 with the switching valves V4, V51, V7 and the check valve V51 closed. The low pressure air AL <b> 2 can be supplied to the bubble ejection part 21 by 40.
When the draft is deep, air (AH + AL + AL) merged by the air supply unit 30K is blown out in the same manner as in this embodiment with the check valves V1, V3, V51 and the switching valves V4, V7 closed. The unit 21 can be supplied.
The low-pressure air supply unit 40 and the air supply unit 30K can be operated simultaneously to supply both the air (AH + AL + AL) and the low-pressure air AL2 merged in the air supply unit 30K to the bubble ejection unit 21.

According to the tenth embodiment described above, by connecting a plurality of ejector main bodies 31 in series, more low pressure air AL can be merged with high pressure air AH. Therefore, the flow rate of the air supplied to the bubble ejection part 21 can be further increased.

In this embodiment, the case where the ejector main bodies 31 are connected in series in two stages as the air supply unit 30K has been described. However, the number of ejector main bodies 31 connected in series is not limited to two as long as it is plural. . For example, three or more stages of ejector bodies 31 may be connected in series.

(Eleventh embodiment)
Next, an air-lubricated ship frictional resistance reducing device and ship according to an eleventh embodiment of the present invention will be described with reference to the drawings. In the eleventh embodiment, the same portions as those in the first to tenth embodiments are denoted by the same reference numerals, and redundant description is omitted.
FIG. 11 is a schematic diagram showing the overall configuration of the frictional resistance reduction device for an air-lubricated ship and the ship according to this embodiment.
As shown in FIG. 11, the ship 10 in this embodiment includes a frictional resistance reduction device 20L. The frictional resistance reduction device 20L includes a bubble ejection unit 21, a bubble recovery unit 25, an air supply unit 30L, and a low-pressure air supply unit 40.

The air supply unit 30L includes an ejector body 31 and a charge tank 60. A suction port 32 is connected to the ejector body 31.
The ejector body 31 has a tapered flow path 31r as in the above-described embodiments. The ejector body 31 has a high-pressure air supply pipe 35 connected to the first end 31a and an air supply pipe 22 connected to the second end 31b. The high-pressure air supply pipe 35 in this embodiment is connected to the discharge side of the supercharger 14, and a part of the compressed air discharged from the supercharger 14 is supplied to the first end 31a of the ejector body 31 as high-pressure air AH. It is sent.

A low-pressure air supply pipe 39 is connected to the first end 32 a of the suction port 32. The low-pressure air supply pipe 39 in this embodiment is connected to the bubble recovery unit 25, and the air obtained from the bubbles recovered by the bubble recovery unit 25 is taken into the intake port 32 as the low-pressure air AL.

The charge tank 60 is provided in the middle part of the high-pressure air supply pipe 35. The charge tank 60 can store a certain amount of high-pressure air AH passing through the high-pressure air supply pipe 35. That is, the high-pressure air AH is temporarily stored in the charge tank 60 in the middle of passing through the high-pressure air supply pipe 35, and then sent to the first end 31 a of the ejector body 31 through the high-pressure air supply pipe 35. .

A check valve V <b> 1 is provided in the air supply pipe 22 between the ejector body 31 and the bubble ejection part 21 so as to be openable and closable.
A check valve V3 is provided in the air supply pipe 43 between the blower 42 and the bubble ejection part 21 so as to be openable and closable.
In the high-pressure air supply pipe 35 that takes in the high-pressure air AH from the supercharger 14, a switching valve V4 is provided so as to be openable and closable. The switching valve V4 intermittently flows the high-pressure air AH from the high-pressure air supply pipe 35 to the ejector body 31 and adjusts the flow rate thereof.
In the high-pressure air supply pipe 35, a flow rate adjustment valve V8 is provided on the downstream side of the charge tank 60 so as to be openable and closable. High-pressure air AH having a flow rate corresponding to the opening degree of the flow rate adjustment valve V8 is supplied from the charge tank 60 to the ejector body 31. That is, the charge amount of the high-pressure air AH to the charge tank 60 can be adjusted by the flow rate adjustment valve V8.
A check valve V5 is provided in the low-pressure air supply pipe 39 that takes in air obtained from the bubbles recovered by the bubble recovery unit 25 as low-pressure air AL.

In the air supply unit 30L, when the switching valve V4 is opened after the switching valve V4, the flow rate adjustment valve V8, and the check valve V5 are closed, the high-pressure air AH compressed by the supercharger 14 through the high-pressure air supply pipe 35 is The charge tank 60 is charged. Next, when the flow regulating valve V8 is opened and the check valve V1 is further opened, the high pressure air AH compressed by the supercharger 14 from the charge tank 60 through the high pressure air supply pipe 35 is provided in the flow path 31r of the ejector body 31. A part of is sent. The flow rate of the high-pressure air AH sent into the flow path 31r gradually increases in the ejector body 31, and a negative pressure is generated in the flow path 31r. The high pressure air AH is temporarily stored in the charge tank 60 in the middle of the high pressure air supply pipe 35. By storing in the charge tank 60 in this way, the pulsation of the high-pressure air AH is reduced.

Subsequently, the check valve V5 is opened. Then, due to the negative pressure in the ejector body 31, low-pressure air AL that is air collected by the bubble collecting unit 25 flows from the first end portion 32 a of the suction port 32. The low-pressure air AL that has flowed into the flow path 32r is drawn into the flow path 31r of the ejector body 31, merges with the high-pressure air AH within the flow path 31r, and is sent out from the second end 31b of the ejector body 31. Thereby, air obtained by adding the low-pressure air AL to the high-pressure air AH is supplied to the bubble ejection portion 21.

The frictional resistance reduction device 20L can supply air to the bubble ejection unit 21 by selectively operating the air supply unit 30L and the low-pressure air supply unit 40. Thereby, for example, when the draft is shallow, the low-pressure air supply unit 40 supplies the low-pressure air AL2 to the bubble ejection unit 21, and when the draft is deep, the air supply unit 30L supplies the high-pressure air AH and the low-pressure air AL. It can supply to the bubble ejection part 21. By simultaneously operating the low-pressure air supply unit 40 and the air supply unit 30L, the high-pressure air AH, the low-pressure air AL, and the low-pressure air AL2 can be simultaneously supplied to the bubble ejection unit 21.

According to the eleventh embodiment described above, in particular, since the high-pressure air AH supplied to the ejector body 31 passes through the charge tank 60, the influence of pulsation of the high-pressure air AH generated on the output side of the supercharger 14 is affected. Can be suppressed. As a result, the high-pressure air AH can be supplied to the ejector body 31 at a stable flow rate. As a result, in the ejector body 31, the low pressure air AL can be stably merged with the high pressure air AH, and bubbles can be stably generated from the bubble ejection portion 21.

(Twelfth embodiment)
Next, an air-lubricated ship frictional resistance reducing device and ship according to a twelfth embodiment of the present invention will be described with reference to the drawings. In the twelfth embodiment, the same portions as those in the first to fifth embodiments are denoted by the same reference numerals, and redundant description is omitted.
FIG. 12 is a schematic diagram showing the overall configuration of the friction resistance reducing device for an air lubricated ship and the ship according to this embodiment.
As shown in FIG. 12, the ship 10 in this embodiment includes a frictional resistance reducing device 20M. The frictional resistance reduction device 20M includes a bubble ejection unit 21, a bubble recovery unit 25, and an air supply unit 30M.

The air supply unit 30M includes an ejector body 31 and a charge tank 70.
The ejector body 31 has a tapered flow path 31r as in the above-described embodiments. A high pressure air supply pipe 35 is connected to the first end 31 a of the ejector body 31, while an air supply pipe 22 is connected to the second end 31 b of the ejector body 31. The high-pressure air supply pipe 35 in this embodiment is connected to a high-pressure air supply source 37 such as a turbo compressor.

The charge tank 70 is provided in an intermediate portion of the high-pressure air supply pipe 35, and can store a certain amount of high-pressure air AH passing through the high-pressure air supply pipe 35, similarly to the charge tank 60 of the eleventh embodiment. ing. That is, the high-pressure air AH compressed by the high-pressure air supply source 37 is temporarily stored in the charge tank 70 while passing through the high-pressure air supply pipe 35, and then sent to the first end 31 a of the ejector body 31. It is.

A low-pressure air supply pipe 39 is connected to the first end 32 a of the suction port 32. The low-pressure air supply pipe 39 in this embodiment is connected to the bubble recovery unit 25, and air obtained from the bubbles recovered by the bubble recovery unit 25 is taken into the suction port 32 as low-pressure air AL.

A check valve V <b> 1 is provided in the air supply pipe 22 between the ejector body 31 and the bubble ejection part 21 so as to be openable and closable.
A check valve V5 is provided in the low-pressure air supply pipe 39 that takes in air obtained from the bubbles recovered by the bubble recovery unit 25 as low-pressure air AL.
In the high-pressure air supply pipe 35, a flow rate adjustment valve V9 is provided on the downstream side of the charge tank 70 so as to be openable and closable. The flow rate adjusting valve V9 has the same function as the flow rate adjusting valve V8 for the charge tank 60 described above with respect to the charge tank 70.

In the air supply unit 30M, the high pressure air supply source 37 is started from the state where the check valves V1, V5 and the flow rate adjustment valve V9 are closed. Then, the high pressure air AH pressurized by the high pressure air supply source 37 is charged in the charge tank 70. Next, when the flow regulating valve V9 is opened, the high-pressure air AH charged in the charge tank 70 is sent into the flow path 31r of the ejector body 31. Thereby, the check valve V1 is opened. In this way, the high pressure air AH is stored in the charge tank 70, so that the pulsation of the high pressure air AH is reduced.

The flow rate of the high-pressure air AH sent into the flow path 31r gradually increases in the ejector body 31, and a negative pressure is generated in the flow path 31r. Then, the check valve V5 is opened by the negative pressure in the ejector body 31, and low-pressure air AL, which is air collected by the bubble collection unit 25, flows from the first end 32a of the suction port 32. The low-pressure air AL that has flowed into the flow path 32r is drawn into the flow path 31r of the ejector body 31, merges with the high-pressure air AH within the flow path 31r, and is sent out from the second end 31b of the ejector body 31. Thereby, air obtained by adding the low-pressure air AL to the high-pressure air AH is supplied to the bubble ejection portion 21.

According to the above-described twelfth embodiment, since the high-pressure air AH supplied to the ejector body 31 passes through the charge tank 70, the high-pressure air supply source 37 such as a compressor is operated similarly to the eleventh embodiment. The pulsation of the high-pressure air AH that occurs together can be suppressed. As a result, bubbles can be generated stably from the bubble ejection portion 21.

(Other variations)
The present invention is not limited to the above-described embodiments, and includes various modifications made to the above-described embodiments without departing from the spirit of the present invention. That is, the specific shapes, configurations, and the like given in the embodiment are merely examples, and can be changed as appropriate.
For example, the configurations disclosed in the above embodiments can be combined as appropriate.

The present invention can be applied to a frictional resistance reducing device for an air-lubricated ship that jets air around the hull and reduces the frictional resistance generated between the hull and the surrounding water. According to this frictional resistance reduction device, it is possible to secure a necessary air flow rate while suppressing an increase in the number of parts, and to obtain a sufficient energy saving effect and a CO ₂ emission reduction effect.

10 Ship (Air lubricated ship)
11 Hull 11b Ship Bottom 11f Bow 11r Stern 12 Screw 12s Shaft 13 Main Engine 14 Supercharger (High Pressure Air Supply Source, Auxiliary Equipment)
20A, 20B, 20C, 20D, 20E, 20F, 20G, 20H, 20J, 20K, 20L, 20M Friction reduction device 21 Bubble ejection part 22 Air supply pipe 25 Bubble recovery parts 30A, 30C, 30D, 30E, 30F, 30G, 30H, 30J, 30K, 30L, 30M Air supply part 31, 31A, 31B Ejector body (ejector)
31a First end 31b Second end 31r Channel 32 Suction port 32a First end 32b Second end 32r Channel 35 High pressure air supply pipe 37 High pressure air supply source 38 Low pressure air supply source 39 Low pressure air supply pipe 39a Branch pipe 39b Branch pipe 40 Low-pressure air supply section (air pressurization section)
41 Atmospheric introduction pipe 41a First end 41b Second end 42 Blower 43 Air supply pipe 49 Connection pipe 60, 70 Charge tank 61 Atmospheric introduction pipe 62 Blower AH High pressure air AL Low pressure air AL2 Low pressure air L Water line V1 Check valve V2 Switching valve V3 Check valve V4 Switching valve V4 ′ Switching valve V5 Check valve V6 Switching valve V7 Switching valve V8 Flow rate adjusting valve V9 Flow rate adjusting valve V51 Check valve

Claims (12)

1. A frictional resistance reducing device for an air-lubricated ship that blows out air around a hull to reduce a frictional resistance generated between the hull and surrounding water,
   An ejector having a flow path through which high-pressure air supplied from a high-pressure air supply source flows, and drawing low-pressure air having a pressure lower than that of the high-pressure air into the flow path;
   A frictional resistance reduction device for an air-lubricated ship, comprising: a bubble ejection unit that generates bubbles around the hull by ejecting the high-pressure air and the low-pressure air discharged from the ejector.
2. The friction resistance reducing device for an air-lubricated ship according to claim 1, wherein the channel has a channel cross-sectional area that gradually decreases from the upstream side toward the downstream side.
3. 3. The frictional resistance reduction device for an air-lubricated ship according to claim 1, wherein the high-pressure air supply source is a main machine that propels the hull or an auxiliary machine that supplies air to the main machine.
4. 3. The friction resistance reducing device for an air-lubricated ship according to claim 1, wherein the high-pressure air supply source is a compressor that compresses the atmosphere.
5. A bubble recovery part for recovering the bubbles ejected from the bubble ejection part;
   The friction resistance reducing device for an air-lubricated ship according to any one of claims 1 to 4, wherein the low-pressure air is the air bubbles recovered by the air bubble recovery unit, and air taken from the atmosphere and compressed by a blower. .
6. A bubble recovery part for recovering the bubbles ejected from the bubble ejection part;
   The friction resistance reducing device for an air-lubricated ship according to any one of claims 1 to 4, wherein the low-pressure air is obtained from the bubbles recovered by the bubble recovery unit.
7. The apparatus for reducing frictional resistance of an air-lubricated ship according to any one of claims 1 to 4, wherein the low-pressure air is air taken from the atmosphere.
8. The friction resistance reducing device for an air-lubricated ship according to any one of claims 1 to 4, wherein the low-pressure air is obtained by compressing air taken from the atmosphere with a blower.
9. The friction of an air-lubricated ship according to claim 4, further comprising a supercharger that compresses and supplies combustion air to a main engine that propels the hull, and the low-pressure air is air compressed by the supercharger. Resistance reduction device.
10. An air pressurization unit that compresses air taken in from the atmosphere and supplies the compressed air to the bubble ejection unit;
    The frictional resistance reduction device for an air-lubricated ship according to any one of claims 1 to 9, wherein air can be selectively supplied to at least one of the air pressurization unit and the ejector to the bubble ejection unit. .
11. The apparatus for reducing frictional resistance of an air-lubricated ship according to any one of claims 1 to 10, further comprising a charge tank that temporarily stores the high-pressure air upstream of the ejector.
12. A ship provided with the friction resistance reducing device for an air-lubricated ship according to any one of claims 1 to 11.

Images