Marine propulsion systems

Abstract

A marine propulsion system is provided, comprising at least one air intake sail (3), said at least one air intake sail (3) comprising an air intake system (10) and a transmission section (8) for driving the rotation of said air intake sail (3), said air intake sail (3) comprising at least two air intake areas (7) symmetrically arranged on either side of said air intake sail (3), said air intake areas (7) comprising variable air intake means. A marine propulsion system is provided, making it possible to reduce fuel consumption and pollutant emissions of a marine vessel by using an improved air intake sail.

Description

[Technical Field]

[0001] The present invention relates to a ship propulsion system, and more particularly to a ship propulsion system comprising one or more intake sails. [Background technology]

[0002] Each vessel needs to generate power to navigate. The most widely used method of generating such power is through the use of systems that utilize hydrocarbons as an energy source. This presents two problems: the costs associated with fuel consumption and the pollution emissions resulting from its use. This problem is particularly relevant to large-capacity merchant vessels involved in maritime transport.

[0003] Other technologies utilize alternative energy sources that enable the generation of progressive electricity, which can complement or replace conventional hydrocarbon-based methods. This can reduce fuel consumption on ships and, if the alternative energy source is also renewable, reduce pollutant emissions. One of these energy sources is wind.

[0004] Wind-assisted ship propulsion systems are known as WASP (Wind Assisted Ship Propulsion). Several systems can be considered as such means (e.g., sails, kites, "Flettner" rotors, intake sails, etc.).

[0005] When wind affects these WAPS, it generates a force perpendicular to the wind direction called lift (L). Aerodynamic drag (D) also occurs. Generally, these forces are expressed in a dimensionless way through the lift and drag coefficients.

[0006] C L =L / (1 / 2 ρ V 2 S)

[0007] C D =D / (1 / 2ρ V 2 S)

[0008] On a ship, the apparent wind can occur from any direction. The direction of the apparent wind with respect to the ship's course (β) determines the use of the WAPS thrust through the following formula.

[0009] C R =C L senβ - C D cosβ

[0010] C R is known as the driving force coefficient. It has been observed that the lift and drag coefficients contribute via the values of the sine and cosine functions in different ways for each course. Therefore, the operation of the WAPS is related to the aerodynamic characteristics expressed as the lift and drag coefficients. It has been observed that there is a dead or unusable area that includes an arc around the bow of about 15 degrees. The size of this unusable area depends, inter alia, on the relationship between the lift coefficient and the drag coefficient.

[0011] The present invention relates to an improvement in the operation of a propulsion system including an intake system composed of a thick side surface having a rear spoiler or fin (referred to as a "flap") that enables intake of the boundary layer of the fluid around a sail (hereinafter referred to as an "intake sail" or simply a "sail"). This propulsion system was first disclosed in a wind power motor (Patent Document 1) and is more specifically disclosed in a turbo boiler or turbo sail (Patent Documents 2 - 3). These systems can be used as auxiliary propulsion systems or, if possible depending on the type of ship, as the main propulsion system. The usefulness of this system is not limited to ship propulsion and can be used as part of the side of a wind turbine for energy production or for any other application that requires a very large lift coefficient.

[0012] The main difference between an intake sail and a conventional sail or passive wing is that an intake system that allows intake of the fluid boundary layer can control and delay side stall and achieve a much higher lift coefficient. Since aerodynamic forces are proportional to the surface of the sail, a high lift coefficient makes it possible to reduce the area required to obtain the same overall force. As a result, it becomes a much more compact system, or when applied to a ship, the number of sails on deck can be increased. In addition, it results in a device with potentially lower weight and cost that has less impact on the visibility requirements of the ship.

[0013] In operation, the intake sail is similar to the wing of an aircraft or the sail of a conventional sailing ship. Wind hitting the sail generates lift (L) and aerodynamic drag (D), producing a certain amount of propulsive force.

[0014] The control of these aerodynamic forces is carried out by orienting the sail with respect to the incident wind (called the angle of attack), as a conventional sail does, and further by controlling the intake of the boundary layer.

[0015] This system produces a positive return when the net power generated by the sail is positive. This is affected by the fact that the aerodynamic forces generate a positive propulsive force greater than the power consumed by the intake system. By analogy, an intake coefficient can be defined based on the power consumption.

[0016] C a =P consumed / 0,5ρV3S

[0017] The net propulsive force is the product of the propulsive force and the ship's speed (V S ). The propulsive force depends on the square of the wind speed (V 2 ), while the power consumption depends on the cube of the wind speed (V 3 ). The net power can be expressed as follows.

[0018] Pnet = 1 / 2 ρ V 2 S(V S ·C R -V·C a )

[0019] In the range of available wind intensities, the ship speed is typically lower than the apparent wind speed for almost all motors and sailing ships. From the above equation, it can be seen that in order to obtain positive performance of the propulsive force, the following must be satisfied.

[0020] C R >(V / V S )C a

[0021] The above equation reveals the multiplicative effect on the intake coefficient of the speed ratio of the apparent speed to the ship speed.

[0022] In the current state of the art, as described in Patent Documents 1-3, the intake of the air flow is performed through the intake area. The intake is performed through one or several fans provided inside the body of the sail, which has a tubular part and a large thickness, and this generates a uniform descent (or intake). This body functions as an intake chamber into which the fluid is intake. This means that the pressure is uniform throughout the body. It is stated that it is possible to vary the size and the transmittance of the intake area along with the height of the sail in order to adapt to the wind speed gradient along with the height.

Prior Art Documents

Patent Documents

[0024] Therefore, an object of the present invention is to provide a ship propulsion system that enables a reduction in the fuel consumption and pollutant emissions of a ship by using an improved intake sail.

[0025] The objective of the present invention is to achieve the intake coefficient (C a By controlling the intake coefficient (C) more precisely, on the one hand, the intake coefficient (C) can be controlled. a ) reduces the thrust coefficient (C) while increasing lift and reducing aerodynamic drag. R The goal is to improve net power by increasing ).

[0026] The object of the present invention is to reduce the required intake cost (Q) and pressure jump (ΔP). An equivalent method of expressing the intake coefficient is to use these two variables and the efficiency (η) of the compressor or fan. fan This is achieved by utilizing ).

[0027] C a= Q·ΔP / η fan

[0028] In this way, by configuring the intake system to minimize intake costs and reduce pressure jumps, the intake coefficient can be reduced, or power consumption can be reduced.

[0029] The object of the present invention is to improve the efficiency of an intake sail by increasing the net thrust supplied through an optimized design of an intake system that enables intake of the fluid boundary layer around the sail, compared to the latest technology.

[0030] This optimized design allows for more precise control of the boundary layer and its intake, thereby improving the intake coefficient (C) a This achieves a reduction in the lift coefficient (C), while on the other hand, L ) increases, and the thrust coefficient (CR To increase the aerodynamic drag coefficient (C D ) reduces.

[0031] Reducing intake costs is achieved by selective intake of airflow at appropriate locations. Airflow around the sides must be evacuated before leaving the surface. Intake is performed through a porous surface, which can take various forms (i.e., rows of holes, slots, channels, or any other form that allows fluid to pass from the outside to the inside of the sail through intake).

[0032] The intake surface is not uniform, but it is adapted to the specific characteristics of the airflow at each point on the surface. At the start of intake, the pressure on the outer arc surface of the side is minimal on the intake surface. As the airflow moves downstream toward the flap, the pressure increases. By adjusting the intake pressure at each point on the side in this way, the total pressure jump at each point is minimized (ΔP). When this is combined with an appropriate porosity of the surface, the intake cost (Q) is minimized.

[0033] A system that enables selective intake of airflow can be considered a pneumatic system. Intake occurs through a housing that communicates with the interior of the sail, and an intermediate pressure drop occurs through this housing. The housing consists of forming an intermediate chamber around the intake area so that an intermediate intake chamber is formed. This solution is shown when one or more fans are used to pressurize the main chamber through which the fluid of the external airflow is drawn in.

[0034] Another possibility is to use a dedicated fan or compressor at each intake location. In this way, each fan draws in airflow through the pipe system.

[0035] By incorporating a dedicated fan into the flap, the air intake can be extended beyond the main body of the sail. This allows for air intake over the flap, substantially reducing bottom drag and increasing the lift coefficient. The energy cost of drawing air into the flap is minimal because the pressure in that region is approximately atmospheric pressure, and the power required for intake is minimal.

[0036] Since the flap is movable, the flap's intake can be integrated into the sail body so that at each operating position the flap is connected to the sail body and the intake capacity is transmitted to the sail through the corresponding connection point or pipe. [Means for solving the problem]

[0037] The ship propulsion system according to the present invention is defined in claim 1 and comprises an intake sail, the intake sail comprising an intake system and a transmission unit for driving the rotation of the intake sail, the intake sail comprising at least two intake regions symmetrically provided on both sides of the intake sail, the intake regions comprising variable intake means.

[0038] According to one embodiment, the variable intake means is a set of holes in an intake region having different diameters, in other words, different porosity levels.

[0039] According to one embodiment, the variable intake means includes a housing provided in at least one intake region that divides each intake region into multiple sections.

[0040] Furthermore, if necessary, at least one intake region can be provided on the flap.

[0041] According to one embodiment, the intake region provided in the flap or each intake region is equipped with a housing and / or variable porosity.

[0042] The marine propulsion system according to the present invention may also include two or more intake systems related to different intake regions.

[0043] For example, each housing may be associated with an intake system.

[0044] According to one embodiment, the intake region provided on the flap includes an intake system provided on the flap. [Effects of the Invention]

[0045] The propulsion system according to the present invention makes it possible to provide, in particular, the following advantages:

[0046] By better controlling boundary layer intake (variable porosity, housing, multiple intake systems), unnecessary excess intake is minimized, and therefore, the required intake power consumption is reduced. This makes the sail more efficient by generating more thrust for the vessel while simultaneously reducing the sail's power consumption.

[0047] By extending the intake to the flap and controlling its variable properties, it becomes possible to further delay airflow separation by increasing the angle of attack and asymmetry, thus increasing the aerodynamic coefficient and improving sail performance.

[0048] To better understand this disclosure, several drawings are provided to illustrate practical cases of embodiments, only as schematic and non-limiting examples. [Brief explanation of the drawing]

[0049] [Figure 1] This is a side view of a ship incorporating the propulsion system according to the present invention. [Figure 2] This is a side view of an intake sail used in a propulsion system according to the present invention. [Figure 3] This is a bottom perspective view of an intake sail used in the propulsion system according to the present invention. [Figure 4] This is a top view of an intake sail used in the propulsion system according to the present invention, showing the intake system. [Figure 5] This is a cross-sectional view of an intake sail used in the propulsion system according to the present invention, showing the transmission and power unit. [Figure 6] This is a modified diagram showing the bottom of an intake sail used in the propulsion system of the present invention, the intake sail being tiltable around a substantially horizontal axis. [Figure 7] This is a cross-sectional view of a different embodiment of the intake sail. [Figure 8] This is a cross-sectional view of a different embodiment of the intake sail. [Figure 9] This is a cross-sectional view of a different embodiment of the intake sail. [Figure 10] This is a cross-sectional view of a different embodiment of the intake sail. [Figure 11] This is a cross-sectional view of a different embodiment of the intake sail. [Figure 12] This is a cross-sectional view of a different embodiment of the intake sail. [Figure 13] This is a cross-sectional view of a different embodiment of the intake sail. [Figure 14] This is a cross-sectional view of a different embodiment of the intake sail. [Modes for carrying out the invention]

[0050] For simplification, these diagrams show only one of the intake regions on either the sail body or the flap. It should be understood that the intake region is symmetrical on both sides of the body and flap.

[0051] Figure 1 shows a ship 2 equipped with the propulsion system according to the present invention.

[0052] The propulsion system comprises at least one intake sail 3 including an outer cover 4 which may be rigid or flexible, and the intake sail 3 is rotatable about its longitudinal axis 5.

[0053] The intake sail 3 also comprises at least one flap 6 that is rotatable between different positions, and at least two equally symmetrical intake regions 7 having a plurality of holes, the intake regions 7 comprising variable intake means.

[0054] According to one embodiment, variable intake is achieved by changing the diameter of the holes in each intake region 7 relative to each other, or in other words, by changing the degree of porosity of the intake region 7 along the intake region 7.

[0055] The intake sail 3 also comprises a fan-type or equivalent intake system 10 that draws in a portion of the airflow from the outer arc surface of its side, and at least one transmission unit 8. The transmission unit 8 can be electric or hydraulic and rotates the intake sail 3. The intake sail 3 comprises an electric or hydraulic power unit 18 that drives the transmission unit 8.

[0056] Furthermore, the intake sail 3 is connected to the ship's deck 2 using a support structure 17, which may include a gear mechanism or bearing structure. The support structure 17 can support the entire weight and can restrict the lateral movement of the intake sail 3.

[0057] Figure 6 shows a modified configuration in which the lower part of the intake sail 3 includes an inclined support 19. The inclined support 19 allows the intake sail 3 to tilt relative to the vertical, i.e., to tilt substantially relative to a horizontal axis, and drives a motor 20 or one or more cylinders.

[0058] Different embodiments of the intake sail are shown in Figures 7 to 14, which differ from one another by the arrangement of the intake region and / or the means used to achieve variable intake control. For simplification, these figures show only the intake region on one of the two sides of the sail body and flap. It should be understood that the intake region is symmetrical on both sides of the body and flap.

[0059] Figure 7 shows a configuration including a single overall intake region 7. Along the intake region 7, the porosity of the region is adjusted to adjust / adapt the intake as the outer arc surface advances, and the holes in the intake region 7 have different diameters and / or variable porosity from each other.

[0060] Due to intake, external pressure P ext Different internal pressure P int A graph is generated, and the arrows indicate the direction of airflow absorbed from the boundary layer (the layer of air very close to the surface of the sail).

[0061] Figure 8 shows an embodiment comprising multiple intake regions 7, i.e., sections with holes separated from each other, which allows for greater control of the intake.

[0062] Note that these intake regions 7 extend across the entire height of the sail.

[0063] Figure 9 shows different embodiments, each comprising a single intake region 7 but divided into different housings 19 that form variable intake means, for example, having different permeability (size and number of holes). In this way, by centrally intake, different intake levels (or pressures) are generated in each section 19, thus providing greater intake control.

[0064] Figure 10 shows an embodiment that includes different intake regions 7 and housings 19, where the intake regions 7 are separated from each other, allowing for better control of each region.

[0065] Figure 11 shows another embodiment, which is very similar to the previous embodiment, with the difference being that each housing 19 can independently take in air using an independent intake system 10.

[0066] In the embodiment shown in Figure 12, the flap 6 includes an intake region 7 that extends over the entire height.

[0067] It should be noted that the intake region 7 on the flap 6 may be included in any of the embodiments described herein, and the flap 6 may have two or more intake regions 7.

[0068] The embodiment shown in Figure 13 is a modification of the previous embodiment, differing in that the intake system 10 is located inside the flap 6 for the intake region 7 of the flap 6 itself.

[0069] Finally, in the embodiment shown in Figure 14, the intake area 7 of the flap 6 may also comprise one or more housings 19, each associated with the intake system 10.

[0070] Furthermore, a sealing means may be provided on one side of the flap 6, while the other side may be, for example, operable.

[0071] Furthermore, in all the embodiments described above, the intake sail 3 is symmetrical; that is, when it is stated that one or more intake regions 7 are on one side, it should be noted that they are also on the other side, not just one side.

[0072] While specific embodiments of the present invention have been referenced, it will be apparent to those skilled in the art that the propulsion systems described are subject to numerous modifications and alterations, and that all described details can be replaced by other technically equivalents without departing from the scope of protection defined by the appended claims.

Claims

1. It comprises at least one intake sail (3), The at least one intake sail (3) comprises an intake system (10) and a transmission unit (8) that drives the rotation of the intake sail (3). The intake sail (3) comprises at least two intake regions (7) symmetrically provided on both sides of the intake sail (3), Each of the at least two intake regions (7) is provided with a plurality of holes of different sizes as a variable intake means. Marine propulsion systems.

2. The variable intake means includes a housing (19) provided in at least one intake region (7) that divides each intake region (7) into multiple sections. The ship propulsion system according to claim 1.

3. At least one of the intake regions (7) is provided on the flap (6). A ship propulsion system according to claim 1 or 2.

4. The intake region (7) provided on the flap (6), or each intake region (7), includes the housing (19). The ship propulsion system according to claim 3.

5. Includes two or more intake systems (10) associated with different intake regions (7) A ship propulsion system according to claim 1 or 2.

6. Each housing (19) is associated with an intake system (10). The ship propulsion system according to claim 2 or 4.

7. The intake region (7) provided on the flap (6) includes the intake system (10) provided on the flap (6). The ship propulsion system according to claim 3.

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