JP6664907B2 - Air generator - Google Patents

Description

  The present invention relates to an air generator for an air lubrication system.

  Conventionally, as technologies related to air lubrication systems for ships, an air inlet that is open to the atmosphere on the ship, an outlet that is provided at the bottom of the ship so that it is immersed in water, and air that is pumped in a direction from the air inlet to the outlet There is known an air supply unit that includes an air supply unit (see, for example, Patent Document 1). In this prior art, the hull is air-lubricated and the frictional resistance is reduced by causing the air pumped by the air supply means to flow out of the outlet.

JP 2012-214113 A

  In the above prior art, the power (energy) of the air supply means is required to generate air for lubricating the hull. In recent years, it has been desired for an air lubrication system to reduce energy for generating air for lubricating a hull.

  An object of the present invention is to provide an air generating device of an air lubricating system capable of saving or reducing energy for generating air for lubricating a hull.

  The air generator of the air lubrication system according to the present invention has an inflow port through which water around the hull can enter, an air introduction port that is open to the atmosphere, a first flow path that connects the air introduction port and the inflow port, An outlet provided in the hull so as to be immersed in water, a second flow path branched from the middle of the first flow path via a branch part and connected to the flow outlet, and heading from the air inlet to the branch part A check valve that allows air to flow in the direction.

  In the air generator of this air lubrication system, for example, as the position of the wavefront with respect to the hull rises or the hull moves, the water level inside the first flow path rises and the area inside the first flow path decreases. At this time, the check valve does not allow the air inside the first flow path to flow in the direction from the inflow port to the air introduction port. Therefore, the pressurized air inside the first flow path flows from the branch portion to the second flow path, flows toward the outlet along the second flow path, and flows out from the outlet. By utilizing the energy of the wave or the hull motion, or both the energy of the wave and the motion of the hull, power for pumping air can be omitted. As a result, energy for generating air for lubricating the hull can be saved.

  Further, the air generating device of the air lubrication system may include an air pumping device for pumping air in a direction from the branch to the outlet, in the second flow path. In this case, even when the wave energy or the hull motion, or both the wave energy and the hull motion cannot be used, for example, due to the lowering of the position of the wavefront with respect to the hull, the air is discharged from the outlet by the air pumping device. Can be. Further, for example, as the position of the wavefront with respect to the hull rises, pressurized air inside the first flow path flows from the branch portion to the second flow path. By this air flow, for example, the power of the air pumping device when air is pumped at a constant flow rate is reduced. By using the energy of the wave or the hull motion, or both the energy of the wave and the motion of the hull, the power of the air pumping device can be reduced.

  The inflow port may be provided at the bottom of the hull. Since the bottom of the hull is usually immersed in water, water around the hull easily enters the inflow port. Therefore, it is possible to easily utilize the energy of the wave or the hull motion, or both the energy of the wave and the motion of the hull.

  Further, the inflow port may be provided in the first region immersed in water at the bow of the hull. Providing an inlet at the bottom of the hull results in a loss of hull propulsion energy due to the relative speed between the hull and water, for example, when water enters the inlet. In the first area, the bow of the hull functions to dampen the water, so that the relative speed between the hull and the water in the traveling direction of the hull is reduced. Therefore, by providing the inflow port in the first region, it is possible to reduce the loss of propulsion energy caused by the relative speed between the hull and the water.

  Further, the inflow port may be provided in the second area near the waterline at the bow of the hull. For example, if the wavefront is located below the inlet, the water does not enter the inlet, so that there is no loss of propulsion energy that occurs when the water enters the inlet. Therefore, by providing the inflow port in the second region, the loss of propulsion energy can be further reduced.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to omit or reduce the energy for generating the air which lubricates a hull.

It is a schematic side view showing the air generator concerning a 1st embodiment of the present invention. It is a schematic side view showing an air generator concerning a 2nd embodiment of the present invention. It is an outline side view showing the air generator concerning a 3rd embodiment of the present invention. It is a schematic side view showing the air generator concerning a 4th embodiment of the present invention. It is the schematic which shows an example of a ship.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or corresponding elements will be denoted by the same reference symbols, without redundant description. In the following description, the terms “front”, “rear”, “up”, and “down” correspond to the captain (front-back) direction and the up-down direction of the hull, respectively.

[First Embodiment]
FIG. 1 is a schematic side view showing the air generator according to the first embodiment of the present invention. The air lubrication system 1 to which the air generator 2 according to the first embodiment of the present invention is applied is mounted on a ship 10 and covers the bottom 12 of the hull 11 of the ship 10 with air bubbles (air) B so as to cover the hull 11. Lubricate with air. The air generator 2 is a device that generates bubbles B for lubricating the hull 11 with air.

  FIG. 5 is a schematic diagram illustrating an example of a ship. The ship 50 includes a hull 51 having a bow 53 and a stern 54. The bow 53 is located in front of the hull 51. The stern portion 54 is located behind the hull 51. The bow 53 has, for example, a shape in which wave making resistance is reduced in a fully loaded draft state. The bow 53 functions to dampen the water W coming from the front toward the hull 51 when viewed from the hull 51 to be propelled. The stern portion 54 is provided with a propulsion device 55 and a rudder 56 below the waterline SL.

  Returning to FIG. 1, the boat 10 includes a hull 11 having a bow 13. The boat 10 here is a boat having a relatively low draft line SL in the vertical direction of the hull 11 and a so-called shallow draft. Note that the waterline SL corresponds to the water surface when no waves are generated. When a wave is generated, for example, as shown by a wave surface WF, the water surface fluctuates vertically with respect to the water line SL.

  The ship 10 is provided with an air generator 2 at a bow 13 of a hull 11. The air generator 2 includes an inflow port 3, an outflow port 4, an air introduction port 5, a branch portion 6, a check valve 7, a first flow path L1, and a second flow path L2.

  The inflow port 3 allows water W around the hull 11 to enter. The inflow port 3 here is provided so as to open downward at the bottom portion 12 of the bow portion 13. The bottom portion 12 is not limited to the bottom (lowest portion) of the hull 11 and includes an area below the hull 11 that is constantly immersed in the water W. The inflow port 3 may be open in the bottom 12 in a direction other than below (for example, sideways).

  The outflow port 4 is provided on the hull 11 so as to be immersed in the water W. The outlet 4 here is provided so as to open downward at the bottom 12 of the bow 13, and is provided at the bottom 12 of the bow 13 behind the inlet 3. The outlet 4 may be open in the bottom 12 in a direction other than below (for example, sideways).

  The air introduction port 5 is an opening opened to the atmosphere. The air inlet 5 is provided, for example, at the upper end of the hull 11.

  The first flow path L1 is a flow path that connects the air introduction port 5 and the inflow port 3. The first flow path L1 extends so as to cross the bow 13 in the vertical direction. More specifically, the first flow path L1 extends upward from the inflow port 3 at the bow portion 13, bends rearward at the first bent portion C1, extends rearward, and further extends upward at the second bent portion. , And extends upward to reach the air inlet 5. The first flow path L1 is formed of, for example, a pipe.

  The first flow path L <b> 1 has water W that has entered from the inflow port 3 and a region S that is full of air that has been introduced from the air introduction port 5. The water surface WS is located at the position of the wavefront WF in the first flow path L1. Therefore, the inside of the first flow path L1 is partitioned by the water surface WS into a region S filled with air and water W.

  The second flow path L2 is branched at the second bent portion of the first flow path L1 and connected to the outlet 4. Specifically, the second flow path L2 is branched by making the second bent portion of the first flow path L1 into a branch portion 6, and extends downward. That is, the second flow path L2 branches from the middle of the first flow path L1 via the branch part 6, and is connected to the outlet 4. The second flow path L2 is formed in a straight line with, for example, a pipe. The cross-sectional area of the second flow path L2 is, for example, substantially equal to the cross-sectional area of the first flow path L1. The branch portion 6 here is formed by a three-way joint.

  The check valve 7 is provided at the end of the first flow path L1 on the side of the air inlet 5 or between the air inlet 5 and the branch portion 6 in the first flow path L1. The check valve 7 is provided at an end of the first flow path L1 on the side of the air inlet 5. The check valve 7 allows air to flow from the air inlet 5 toward the branch 6, but does not allow air to flow from the branch 6 to the air inlet 5.

  In the air generator 2 configured as described above, for example, the water W enters from the inflow port 3 as the position of the wavefront WF with respect to the hull 11 rises, and the water surface WS inside the first flow path L1 rises. The area S inside the first flow path L1 becomes smaller. As the region S inside the first flow path L1 becomes smaller, the air filled in the region S is pressurized. At this time, the check valve 7 does not allow the air in the region S (the inside of the first flow path L1) to flow in the direction toward the air inlet 5. Therefore, the pressurized air in the region S flows from the branch portion 6 to the second flow path L2, flows toward the outlet 4 along the second flow path L2, and flows out of the outlet 4 as bubbles B. .

  On the other hand, when the position of the wavefront WF lowers with respect to the hull 11, the water W that has entered the first flow path L1 returns to the inflow port 3, and the water surface WS inside the first flow path L1 lowers. The area S inside the first flow path L1 increases. As the area S inside the first flow path L1 increases, the air filled in the area S expands and the pressure in the area S decreases. At this time, the check valve 7 allows air (atmosphere) to flow in a direction from the air inlet 5 to the branch portion 6. Therefore, the next time the position of the wavefront WF rises, the air filled in the region S can be pressurized again, and the pressurized air in the region S flows out from the outlet 4 as bubbles B. Becomes possible.

  As described above, the air generator 2 generates bubbles B that lubricate the hull 11 by utilizing the fact that the position of the wavefront WF repeatedly moves up and down with respect to the hull 11. Such a rise and a descent of the position of the wavefront WF with respect to the hull 11 occur depending on the relative positional relationship between the hull 11 and the position of the wavefront WF. That is, ascending and descending cases include a case caused by the energy of the wave itself, a case caused by the vertical hull movement of the hull 11, and a case caused by both. That is, by using the energy of the wave or the hull motion, or both the energy of the wave and the hull motion, for example, a blower or a compressor for pumping air toward the outlet 4 becomes unnecessary, and the air is pumped. Power can be omitted. As a result, energy for generating bubbles B for lubricating the hull 11 can be saved.

  The inflow port 3 is provided at the bottom 12 of the hull 11. Since the bottom 12 of the hull 11 is usually immersed in the water W, the water W around the hull 11 easily enters the inlet 3. Therefore, it is possible to easily utilize the energy of the wave or the hull motion, or both the energy of the wave and the motion of the hull.

  Note that, as described above, the boat 10 to which the air generator 2 is applied has a relatively low draft line SL in the vertical direction of the hull 11. Therefore, for example, a situation in which the length from the draft line SL to the water surface WS in the first flow path L1 is larger than the length from the draft line SL to the outlet 4 in the second flow path L2 is likely to occur. In this case, when the water surface WS rises, the air in the region S pressurized easily flows out from the outlet 4. That is, by using the energy of the wave or the hull motion, or both the energy of the wave and the motion of the hull, a blower, a compressor, and the like can be easily omitted. Thus, the air generator 2 can be suitably applied to the marine vessel 10 having a relatively low draft line SL in the vertical direction of the hull 11.

[Second embodiment]
FIG. 2 is a schematic side view showing the air generator according to the second embodiment of the present invention. The air lubrication system 1 to which the air generator 2A according to the second embodiment of the present invention is applied is mounted on a boat 20. In this ship 20, the position of the draft line SL in the vertical direction of the hull 21 is located above the position of the draft line SL in the vertical direction of the hull 11 of the first embodiment (the draft is deep), for example, a large tanker or the like. It is a ship.

  The air generator 2A of the marine vessel 20 is particularly different from the air generator 2 of the marine vessel 10 of the first embodiment in that an air pump 8 is provided in the second flow path L2. Further, as the draft of the vessel 20 is deeper than that of the vessel 10, the length of the first flow path L1 is extended on the inflow port 3 side, and the length of the second flow path L2 is increased on the outflow port 4 side. Has been extended. Therefore, the hull 21 of the present embodiment includes a bottom 22 and a bow 23 that are longer in the vertical direction than the hull 11 of the first embodiment.

  The air pumping device 8 pumps the air in the region S in a direction from the branch portion 6 toward the outlet 4. The pneumatic pumping device 8 is provided, for example, on the branch portion 6 side, which is the upper part of the second flow path L2, in order to prevent the air pumping apparatus 8 from being immersed in the water inside the second flow path L2 that has risen due to the fluctuation of the wavefront WF. As the pneumatic feeding device 8, for example, a blower or a compressor can be used. The air pumping device 8 is driven by a predetermined power so that the flow rate of the air to be pumped in the direction from the branch portion 6 to the outlet 4 becomes a predetermined flow rate, for example.

  In the air generator 2 </ b> A, the pressurized air in the region S flows through the branch portion 6 to the air pumping device 8 in the second flow path L <b> 2 as the position of the wavefront WF with respect to the hull 21 increases. Due to this flow of air, the power of the air pump 8 for reducing the flow rate of the air to the predetermined flow rate can be reduced, and the power of the air pump 8 is reduced. By utilizing the energy of the wave or the hull motion, or both the energy of the wave and the hull motion in this manner, the power of the air pumping device 8 can be reduced.

  On the other hand, when the position of the wavefront WF is lowered with respect to the hull 21, the water W that has entered the first flow path L1 returns to the inflow port 3 side, so that the air filled in the region S is not pressurized. In the air generator 2A, even when the air filled in the region S cannot be pressurized, the air is sent out from the outlet 4 as bubbles B by pumping the air by the air pumping device 8. be able to. That is, the air generator 2A can always generate the air bubbles B for lubricating the hull 21 with air.

[Third embodiment]
FIG. 3 is a schematic side view showing an air generator according to a third embodiment of the present invention. In the air generating device 2B according to the third embodiment of the present invention, the inflow port 3 is provided in the first area 23a immersed in the water W at the bow 23 of the hull 21. It is different from the air generator 2A.

  With this change, the first flow path L1 of the air generator 2B is further bent at the third bent portion C2 located below the first bent portion C1, and extends forward to reach the inflow port 3. The third bent portion C2 is located below the draft line SL.

  The first area 23a is an area below the waterline SL in the bow portion 23. In the first region 23a, the bow 23 of the hull 21 functions so as to dam the water W. That is, the bow 23 of the hull 21 dams the water W in the traveling direction of the hull 21, and reduces the relative speed between the hull 21 and the water W in the traveling direction of the hull 21.

  Generally, when an inlet is provided in a hull, for example, when water enters the inlet, a loss of propulsion energy of the hull occurs due to the relative speed between the hull and the water. Here, the bottom of the hull does not function to dampen water in the direction of travel of the hull. Therefore, at the bottom of the hull, the relative speed between the hull and the water in the direction of travel of the hull is not as reduced as at the bow of the hull (the relative speed between the hull and the water at the bottom of the hull is less than the hull at the bow of the hull. Relative to the relative velocity between water and water).

  As described above, in the air generator 2B, the inflow port 3 is provided in the first region 23a immersed in the water W at the bow 23 of the hull 21. In the first region 23a, the water W may be dammed. Since the bow 23 of the hull 21 functions, the relative speed between the hull 21 and the water W in the traveling direction of the hull 21 is reduced. Here, in the present embodiment, the inflow port 3 is provided in the first region 23a. Therefore, in the present embodiment, it is possible to reduce the loss of propulsion energy caused by the relative speed between the hull 21 and the water W.

  Further, in the present embodiment, the air generating device 2B is provided with an air pumping device 8 that pumps air in a direction from the branch portion 6 toward the outlet 4 similarly to the air generating device 2A of the second embodiment. In preparation. Therefore, similarly to the air generator 2A of the second embodiment, the air generator 2B uses the energy of the wave or the hull motion, or both the energy of the wave and the hull motion to control the power of the air pumping device 8. An effect and an effect of being able to reduce are exhibited.

[Fourth embodiment]
FIG. 4 is a schematic side view showing an air generator according to a fourth embodiment of the present invention. In the air generator 2C according to the fourth embodiment of the present invention, the inflow port 3 is provided in the second region 23b near the waterline SL in the bow 23 of the hull 21 in that the air generator 3 of the third embodiment is provided. 2B.

  The second region 23b is, for example, a region above the draft line SL in the bow portion 23, and is a region where the inflow port 3 can be arranged so that the water W around the hull 21 can enter.

  In the air generator 2C, when the position of the wavefront WF with respect to the hull 21 is higher than the position of the inlet 3, the inlet 3 is provided in the first region 23a in the air generator 2B of the third embodiment. As in the case, the water W enters the inlet 3. In this case, similarly to the air generator 2B of the third embodiment, the air generator 2C uses the energy of the wave or the hull motion, or both the energy of the wave and the hull motion, to thereby provide the air pumping device 8C. The effect and effect that the power of can be reduced.

  On the other hand, in the air generator 2 </ b> C, when the position of the wavefront WF with respect to the hull 21 is lower than the position of the inlet 3, the water W does not enter the inlet 3. When the wavefront WF is positioned below the inflow port 3 as described above, the water W does not enter the inflow port 3, so that no loss of propulsion energy occurs when the water W enters the inflow port 3. Therefore, in the air generator 2C, the propulsion energy loss can be further reduced by providing the inflow port 3 in the second region 23b.

  The first to fourth embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments. For example, in the air generators 2, 2A, 2B, and 2C, the first flow path L1 is bent at the first bent portion C1 and the second flow path L2 is linear, but the second flow path L2 May be bent, and the first flow path L1 may be linear.

  In the air generators 2A, 2B, and 2C according to the second to fourth embodiments, an air tank may be provided between the branch portion 6 and the air pressure feeding device 8. In this case, an air tank can be used as a buffer for temporarily storing the pressurized air.

  DESCRIPTION OF SYMBOLS 1 ... Air lubrication system, 2, 2A, 2B, 2C ... Air generator, 3 ... Inlet, 4 ... Outlet, 5 ... Atmospheric inlet, 6 ... Branch, 7 ... Check valve, 8 ... Air pressure feeding Apparatus: 10, 20: ship, 11, 21: hull, 12, 22: bottom, 13, 23: bow, 23a: first area, 23b: second area, L1: first flow path, L2: second Flow path, SL: waterline, W: water.

Claims (7)

An inlet through which water around the hull can enter,
An outlet provided in the hull so as to be immersed in water,
An internal region formed between the inlet and the outlet,
An inlet for introducing air into the internal region,
With
The internal region is divided into a region filled with air and a region filled with water by a water surface,
An air generator in which water enters from the inflow port due to the rise of the wavefront with respect to the hull , and air is pressurized by increasing the water level of the internal region by the entered water, and air flows out from the outflow port. . A first flow path connecting the inflow port and the introduction port,
2. The air generator according to claim 1, further comprising: a second flow path that branches off from the middle of the first flow path and is connected to the outlet. 3.   The air generating device according to claim 2, further comprising a check valve that allows air to flow in a direction from the inlet to the internal region. An air pumping device for pumping air is provided in the second flow path,
The second flow path branches from the middle of the first flow path via a branch portion,
4. The air generator according to claim 2, wherein the air pumping device pumps air in a direction from the branch to the outlet. 5.   The air generator according to any one of claims 1 to 4, wherein the inflow port is provided at a bottom of the hull.   The air generator according to any one of claims 1 to 4, wherein the inflow port is provided in a first area immersed in the water at a bow of the hull.   The air generator according to any one of claims 1 to 4, wherein the inflow port is provided in a second area near a waterline at a bow portion of the hull.

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