Wind power propulsion system

Abstract

According to the present invention, provided is a wind power propulsion system comprising: a wing sail erected and installed on the upper portion of a ship; a rotary member which adjusts the angle of the wing sail in accordance with the wind direction; and a rotary cylindrical unit which is vertically installed, inside the wing sail, such that only a part of the outer circumferential surface thereof is exposed at one side surface of the wing sail, and which rotates in one direction to increase the flow velocity of a flow flowing along the one side surface of the wing sail.

Description

wind propulsion device

[0001] The present invention relates to a wind propulsion device, and more particularly, to a wind propulsion device capable of maximizing the propulsion efficiency of a ship using wind power by increasing the lift acting on a wing sail of an airfoil shape.

[0002] According to recent estimates, the global shipping industry emits about 1 billion tons of carbon dioxide annually, accounting for more than 3% of global carbon dioxide emissions.

[0003] Therefore, measures that can significantly reduce carbon dioxide emissions from the shipping sector are expected to play a significant role in the future, and while various measures with the potential to reduce greenhouse gas emissions, such as reducing ship speeds, biofuels, and carbon-free alternative fuels, are being developed and implemented, interest in wind-assisted propulsion, which does not emit any greenhouse gases at all, is growing.

[0004] Generally, a wind-assisted propulsion system (WAPS) is a device such as a rotor sail, wing sail, kite, or suction wing that converts the kinetic energy of the wind blowing from the sea into the thrust direction of the ship.

[0005] Figures 1 and 2 illustrate a rotor sail (10) and a wing sail (20) according to the prior art, respectively.

[0006] Referring to Fig. 1, the rotor sail (10) is an auxiliary propulsion device that utilizes the Magnus effect, which generates lift when a cylindrical rotor placed in an air flow rotates.

[0007] That is, when the rotor equipped on the hull rotates and the wind blows from the side of the rotor, the Magnus effect generates lift forward, allowing the ship to propel forward.

[0008] However, the rotor sail (10) can only generate propulsion when the wind blows from the side of the ship, so the range of optimal wind direction is limited to crosswinds, and accordingly, there is a disadvantage in that the ship's course must be frequently changed to receive crosswinds during sailing.

[0009] Referring to Fig. 2, the wing sail (20) is a type of wing that is installed vertically on the deck of a ship, and uses the lift generated by the wind flowing into the wing as the propulsion force of the ship.

[0010] These wing sails (20) have a lower lift coefficient than rotor sails, so they are inferior to rotor sails in terms of propulsion efficiency, but they can change direction to have an angle of attack (a) with respect to the relative wind speed (V), so they can generate effective lift that can be used as propulsion over a range of relative wind speeds. However, when the angle of attack (a) exceeds 25°, there is a disadvantage in that a stall phenomenon occurs in which the flow separates from the suction surface and the lift is lost.

[0011] The present invention provides a wind power propulsion device, specifically, a wind power propulsion device that can generate greater propulsive power than existing wing sails by increasing lift by providing a rotating cylindrical portion on the suction side of a wing sail, and can greatly contribute to reducing fuel consumption and greenhouse gas emissions of a ship's main engine.

[0012] The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0013] In order to solve the above-described problem, the present invention provides a wind propulsion device including a wing sail installed on the upper part of a ship, a rotating member for adjusting the angle of the wing sail in response to the wind direction, and a rotating cylindrical member installed vertically on the inner side of the wing sail so that only a portion of the outer surface is exposed on one side of the wing sail, and rotates in one direction to increase the velocity of a flow flowing along one side of the wing sail.

[0014] In addition, the wing sail is formed in an airfoil shape and includes a pressure surface and a suction surface, and a rotating cylindrical portion is arranged on the suction surface side to increase the flow velocity of the flow flowing along the suction surface, thereby reducing the pressure on the suction surface side, thereby providing a wind propulsion device that increases the lift acting on the wing sail.

[0015] Additionally, the rotating cylinder provides a wind propulsion device positioned at a point 0 to 45% of the chord length from the leading edge of the wing sail.

[0016] Additionally, the rotating cylinder provides a wind propulsion device positioned at a point 35 to 45% of the chord length from the leading edge of the wing sail.

[0017] In addition, the rotary member provides a wind propulsion device including a rotary shaft installed at a central point of the chord length of the wing sail and a rotary drive unit connected to the rotary shaft and adjusting the angle of the wing sail to receive the wind speed by rotating the rotary shaft.

[0018] In addition, the rotating cylindrical portion is provided so that only a portion of the outer surface is exposed on the other side of the wing sail, and is disposed on each side of the wing sail, and a wind propulsion device is provided that rotates the rotating cylindrical portion disposed on the side that becomes the suction surface of the wing sail according to the wind direction among a pair of rotating cylindrical portions disposed on each side of the wing sail.

[0019] A wind propulsion device according to an embodiment of the present invention includes a rotating cylindrical part with a portion of the outer surface exposed on the suction surface side of a wing sail formed in an airfoil shape, and by rotating the rotating cylindrical part to increase the velocity of a flow flowing along the suction surface of the wing sail, the pressure on the suction surface side can be reduced, thereby increasing the lift acting on the wing sail of the airfoil shape, thereby increasing the propulsion efficiency of a ship using wind power.

[0020] In addition, when installed on a ship, it can significantly contribute to reducing fuel consumption and greenhouse gas emissions of the ship's main engine by generating greater propulsion power over a wider range of relative wind angles compared to existing wing sails.

[0021] The effects that can be obtained from the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present invention belongs from the description below.

[0022] Figures 1 and 2 illustrate a rotor sail and a wing sail according to the prior art, respectively.

[0023] Figure 3 is a perspective view illustrating the configuration of a wind propulsion device according to one embodiment of the present invention.

[0024] Figure 4 is a plan view illustrating the configuration of a wind propulsion device according to one embodiment of the present invention.

[0025] FIG. 5 illustrates a ship having a wind propulsion device installed according to one embodiment of the present invention.

[0026] Figure 6 is a graph showing the results of computational fluid dynamics analysis of the lift coefficient for the angle of attack of a wing sail according to one embodiment of the present invention.

[0027] Figure 7 illustrates the thrust of a wing sail, a general wing sail, and a rotor sail having a rotating cylindrical section according to one embodiment of the present invention, according to wind direction.

[0028] Figure 8 is a perspective view illustrating the configuration of a wind propulsion device according to another embodiment of the present invention.

[0029] Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the attached drawings.

[0030] The detailed description set forth below, together with the accompanying drawings, is intended to illustrate exemplary embodiments of the present invention and is not intended to represent the only embodiments in which the present invention may be practiced.

[0031] In order to clearly explain the present invention in the drawings, parts that are not related to the description may be omitted, and the same reference numerals may be used for the same or similar components throughout the specification.

[0032] In embodiments of the present invention, expressions such as “or”, “at least one”, etc. may represent one of the words listed together, or a combination of two or more.

[0033] FIG. 3 is a perspective view illustrating the configuration of a wind propulsion device (100) according to one embodiment of the present invention, FIG. 4 is a plan view illustrating the configuration of a wind propulsion device (100) according to one embodiment of the present invention, and FIG. 5 is a view illustrating a ship on which a wind propulsion device (100) according to one embodiment of the present invention is installed.

[0034] The wind propulsion device (100) according to the present invention is a propulsion device for a ship that utilizes wind power, and can be installed on the upper part of the ship, and can propel the ship by changing the kinetic energy of the wind blowing from the sea into the thrust direction of the ship.

[0035] In addition, a rotating cylindrical part (130) having a portion of the outer surface exposed on the suction surface of a wing sail (110) formed in an airfoil shape is built in, and by rotating the rotating cylindrical part (130) to increase the velocity of the flow flowing along the suction surface of the wing sail (110), the pressure on the suction surface side can be reduced, thereby increasing the lift acting on the wing sail (110) of the airfoil shape, thereby increasing the propulsion efficiency of a ship using wind power.

[0036] Referring to FIGS. 3 to 5, a wind propulsion device (100) according to one embodiment of the present invention may include a wing sail (110), a rotating member (120), and a rotating cylindrical portion (130).

[0037] The wing sail (110) can be formed in a cross-section like an airfoil, has a suction surface where the pressure decreases due to a fast flow rate, and a pressure surface where the pressure increases due to a slow flow rate, and lift can be generated from the pressure surface side to the suction surface side.

[0038] These wing sails (110) can be installed vertically on the upper part of the ship, i.e., on the deck, and can provide propulsion power to the ship with lift generated by wind flowing into the wing shape.

[0039] The rotating member (120) can adjust the angle of the wing sail (110) to maximize lift and thrust in response to the wind direction.

[0040] Specifically, the rotating member (120) may include a rotating shaft (121) for rotating the wing sail (110), and a rotating drive unit (122) connected to the rotating shaft (121) to rotate the rotating shaft (121).

[0041] As an example, the rotary drive unit (122) is installed on the deck of a ship, and the rotary shaft (121) is installed on the upper part of the rotary drive unit (122) and can rotate in the forward or reverse direction depending on the driving of the rotary drive unit (122).

[0042] Here, the rotation axis (121) is installed so as to vertically penetrate the wing sail (110) and rotate the wing sail (110). It is installed at the center point of the chord length of the wing sail (110) and can rotate the wing sail (110) left and right depending on the wind direction.

[0043] Accordingly, the wing sail (110) can have its angle adjusted by the rotating member (120) so that the lift and thrust can be maximized in response to the wind direction.

[0044] That is, referring to FIG. 2, the wing sail (110) can be turned by the rotating member (120) to have an angle of attack (a) with respect to the relative wind speed (V), thereby generating effective lift that can be used as propulsion over a wider range of relative wind speeds.

[0045] At this time, the wing sail (110) is mounted on the rotation axis (121) of the rotating member (120) and can be rotated left and right according to the relative wind direction angle (a1) that changes according to the wind direction and the course angle of the ship.

[0046] Referring to FIGS. 3 and 4, the rotating cylindrical portion (130) may be installed vertically on the inside of the wing sail (110) so that only a portion of the outer surface is exposed on one side, and may be provided to rotate in one direction.

[0047] Specifically, the rotating cylindrical portion (130) is arranged parallel to the rotation axis (121) of the rotating member (120) within the wing sail (110). The rotating cylindrical portion (130) may be arranged at a point 0 to 45% of the chord length from the leading edge (front part of the airfoil) of the wing sail (110), preferably at a point 35 to 45% of the chord length, and more preferably at a point 40% of the chord length.

[0048] In addition, the rotating cylindrical portion (130) can be rotated in the direction in which the fluid flows along one side (suction surface) of the wing sail (110). As an example, the rotating cylindrical portion (130) can be rotated by the driving force of a motor including a motor.

[0049] A rotating cylindrical portion (130) like this rotates in one direction on the wing sail (110) to increase the velocity of the flow flowing along the suction surface of the airfoil, thereby preventing flow separation and resulting stall even when the angle of attack is a certain angle or more (e.g., 25° or more).

[0050] Accordingly, the wind propulsion device (100) of the present embodiment can increase the speed of the flow flowing along the suction surface through the rotating cylindrical portion (130) provided on the wing sail (110), thereby reducing the pressure on the suction surface side and increasing the lift acting on the wing sail (110) of the airfoil shape, thereby increasing the propulsion efficiency of a ship using wind power.

[0051] Figure 6 is a graph showing the results of computational fluid dynamics analysis of the lift coefficient for the angle of attack of a wing sail (110) according to one embodiment of the present invention.

[0052] Specifically, FIG. 6 shows the lift coefficient for the angle of attack when the rotating cylindrical part (130) is located at 40% of the chord length and the ratio between the rotational linear speed of the rotating cylindrical part (130) and the relative wind speed, i.e., the rotational linear speed of the rotating cylindrical part (130) / relative wind speed = 4.0, compared to the lift coefficient for the angle of attack of a general wing sail.

[0053] Referring to the graph of Fig. 6, it can be seen that in the case of a wing sail having a rotating cylindrical section as in this embodiment, the lift coefficient is greater than that of a general wing sail.

[0054] In particular, in the case of a general wing sail, when the angle of attack exceeds 25°, a stall phenomenon occurs in which the flow separates from the suction surface and lift is lost, whereas in the case of the wing sail having a rotating cylindrical section of the present embodiment, momentum is supplied to the flow flowing along the suction surface by the rotating rotating cylindrical section, so the phenomenon of flow separation can be prevented.

[0055] Accordingly, the lift coefficient of the wing sail having the rotating cylindrical section of the present embodiment can be continuously increased without stalling until the angle of attack becomes approximately 30°.

[0056] That is, while the maximum lift coefficient of a general wing sail is 1.15, the lift coefficient of the wing sail having a rotating cylindrical part of this embodiment is 1.56, confirming that the lift coefficient has increased by 36%.

[0057] Figure 7 illustrates the thrust of a wing sail, a general wing sail, and a rotor sail having a rotating cylindrical section according to one embodiment of the present invention, according to wind direction.

[0058] Specifically, Fig. 7 shows the thrust of a wing sail, a general wing sail, and a rotor sail having a rotating cylindrical part of the present embodiment installed on a ship, according to wind direction, when the relative wind speed is 6.5 m / s and the ship speed is 15.5 knots.

[0059] In addition, Table 1 below is a table comparing the maximum thrust of a rotor sail (or flattener rotor), a general wing sail, and a wing sail having a rotating cylindrical part, Table 2 is a table comparing the operating effective power of a rotor sail (or flattener rotor), a general wing sail, and a wing sail having a rotating cylindrical part, and Table 3 is a table comparing the reduction rate of the Energy Efficiency Design Index (EEDI) for a rotor sail (or flattener rotor), a general wing sail, and a wing sail having a rotating cylindrical part.

[0060] Rotor Sail General Wing Sail Example Wing Sail Maximum Thrust (kN) 53.0549.2862.32

[0061] Referring to Table 1 and Figure 7, the thrust is maximum when the relative wind direction angle is ±85°, and the maximum thrust is 53.05 kN for the rotor sail and 49.28 kN for the general wing sail, whereas in the case of the wing sail having a rotating cylindrical section of this embodiment, it can be confirmed that it is significantly increased to 62.32 kN.

[0062] Rotor Sail General Wing Sail Example Wing Sail Available Power (kW) 489.3561.3610.0 Available Power Ratio 100% 115% 125%

[0063] Available effective power in Table 2 ( ) is the line speed ( ) is 15.5 knots, and the propulsion efficiency ( ) is calculated using the following mathematical formula assuming 0.70.

[0064]

[0065] Referring to Table 2, the available effective power considering the maximum thrust of each device (rotor sail, general wing sail, and wing sail of this embodiment) and the power required to drive the device is shown to be the best for the wing sail having a rotating cylindrical part of this embodiment compared to the rotor sail and general wing sail, and it can be confirmed that the available effective power per unit is increased by 25% for the wing sail of this embodiment compared to the rotor sail.

[0066] EEDI reduction rate (%) Rotor sail General wing sail Japan Example wing sail 1 unit installed 3.4% 3.7% 4.2% 2 units installed 6.7% 7.5% 8.4% 4 units installed 13.5% 15.1% 16.8%

[0067] When energy-saving devices such as rotor sails or wing sails and wind propulsion devices are installed on a ship, the ship's greenhouse gas emissions are reduced in proportion to the available power, and this is quantified in the Energy Efficiency Design Index (EEDI).

[0068] Referring to Table 3 and FIG. 5, it can be confirmed that when four wing sails having a rotating cylindrical section of the present embodiment are installed on a ship, greenhouse gas emissions can be reduced by 16.8%, and the emission reduction rate is improved by 3.3% compared to a rotor sail and by 1.7% compared to a general wing sail.

[0069] Meanwhile, FIG. 8 is a perspective view showing the configuration of a wind propulsion device (100') according to another embodiment of the present invention.

[0070] Referring to FIG. 8, in the present embodiment, a rotating cylindrical portion (130) may be installed on each side of the wing sail (110).

[0071] As an example, in the present embodiment, among the rotating cylindrical parts (130) arranged on both sides of the wing sail (110), the rotating cylindrical part (130) arranged on the side that becomes the suction surface can be rotated according to the wind direction, thereby increasing the usability of the wing sail (110).

[0072] In addition, as another example, by rotating both of a pair of rotating cylindrical parts arranged on both sides of the wing sail, the rotating cylindrical part arranged on the pressure side rotates in the opposite direction of the wind flowing along the pressure side, and the rotating cylindrical part arranged on the suction side rotates in the direction of the wind flowing along the suction side, thereby increasing the pressure difference between the pressure side and the suction side, thereby increasing the lift acting on the wing sail.

[0073] As another example, the lifting force applied to the wing sail can be increased by rotating the rotating cylindrical part placed on the pressure side and the rotating cylindrical part placed on the suction side in the direction of the wind flow, but rotating the rotating cylindrical part placed on the suction side more quickly.

[0074] As described above, the wind propulsion device (100) according to the embodiment of the present invention has a rotating cylindrical part (130) with a portion of the outer surface exposed on the suction surface side of a wing sail (110) formed in an airfoil shape, and by rotating the rotating cylindrical part (130) to increase the velocity of the flow flowing along the suction surface of the wing sail (110), the pressure on the suction surface side can be reduced, thereby increasing the lift acting on the wing sail (110) of the airfoil shape, thereby increasing the propulsion efficiency of a ship using wind power.

[0075] In addition, when installed on a ship, it can significantly contribute to reducing fuel consumption and greenhouse gas emissions of the ship's main engine by generating greater propulsion power over a wider range of relative wind angles compared to existing wing sails.

[0076] The embodiments of the present invention disclosed in this specification and drawings are merely specific examples presented to easily explain the technical content of the present invention and to help understand the present invention, and are not intended to limit the scope of the present invention.

[0077] Therefore, the scope of the present invention should be interpreted to include all changes or modifications derived based on the technical idea of ​​the present invention in addition to the embodiments disclosed herein.

Claims

1. Wing sail installed on the top of a ship; A rotating member for adjusting the angle of the wing sail in response to the wind direction; and A wind propulsion device comprising a rotating cylindrical portion installed vertically on the inner side of the wing sail so that only a portion of the outer surface is exposed on one side of the wing sail, and rotating in one direction to increase the velocity of a flow flowing along one side of the wing sail.

2. In paragraph 1, The above wing sail is formed in an airfoil shape and includes a pressure surface and a suction surface, A wind propulsion device in which the rotating cylindrical portion is arranged on the suction surface side to increase the flow velocity of the flow flowing along the suction surface side, thereby reducing the pressure on the suction surface side, thereby increasing the lift applied to the wing sail.

3. In paragraph 1, A wind propulsion device in which the above rotating cylindrical portion is positioned at a point 0 to 45% of the cord length from the tip of the wing sail.

4. In paragraph 3, A wind propulsion device in which the above rotating cylindrical portion is positioned at a point 35 to 45% of the cord length from the tip of the wing sail.

5. In paragraph 1, The above rotating member is, A rotating shaft installed at the center point of the code length of the above wing sail; and A wind propulsion device including a rotation drive unit connected to the rotation shaft and adjusting the angle of the wing sail to receive wind speed by rotating the rotation shaft.

6. In paragraph 1, The above rotating cylindrical part, The wing sail is also provided with a portion of its outer surface exposed on the other side, and is placed on each side of the wing sail. A wind propulsion device that rotates the rotating cylindrical portion arranged on the suction surface of the wing sail according to the wind direction among a pair of rotating cylindrical portions arranged on each side of the wing sail.

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