WO2014131873A2

WO2014131873A2 - Wind energy assisted ship

Info

Publication number: WO2014131873A2
Application number: PCT/EP2014/053913
Authority: WO
Inventors: Patrick Englebert
Original assignee: Propelwind S.A.S.
Priority date: 2013-03-01
Filing date: 2014-02-28
Publication date: 2014-09-04
Also published as: WO2014131873A3

Abstract

A wind energy assisted ship has an engine room and one or more main ship propulsion engines of the fuel combustion type arranged in an engine room. The ship further has a room ventilation system adapted to cause forced ventilation of a room onboard the ship. The ventilation system comprises a ventilation air intake duct and a motor driven ventilation fan. The ship further comprises an auxiliary sail propulsion system adapted to provide auxiliary propulsion energy for the ship. This system comprises a sail that is provided with a boundary layer separation control air suction arrangement, wherein the sail is provided with air aspiration apertures in at least said leeward surface of the sail and one or more aspirated air ducts within the sail allowing for air suction through said leeward surface of the sail to control boundary layer separation. The one or more aspirated air ducts are in communication with the ventilation air intake duct.

Description

WIND ENERGY ASSISTED SHIP

The present invention relates to a wind energy assisted ship. In the international shipping industry seaborne ships are commonly propelled by power generated on the basis of fossil fuel that is combusted. These ships commonly have an engine room and one or more main ship propulsion engines of the fuel combustion type arranged in the engine room. The ship propulsion engine or engines are adapted to provide the main propulsion energy for the propulsion of the ship. For example the ship has a propeller shaft that is directly driven by the one or more fuel combustion engines. Or for example the fuel combustion engine(s) drive one or more electrical generators, with the ship having one or more electric motor driven propellers, e.g. as in an electric motor pod-drive.

In operation each ship propulsion engine not only produces effective propulsion energy, but a significant amount of heat is also radiated from the engine which heats the engine room.

Additional heat from exhaust pipes, etc. further contributes to the heating of the engine room.

In order to establish an acceptable environment, e.g. temperature level, in the engine room, e.g. in view of personnel, equipment, etc., it is common to provide the ship with an engine room ventilation system that is adapted to cause forced ventilation of the engine room. Such a system comprises commonly at least one ventilation air intake duct to allow for entry of outside air and at least one motor driven ventilation fan. This fan is often placed in the ventilation air intake duct. Sometimes a further fan is placed in an air exhaust duct of the ventilation system, or - less preferred - no fan is placed in the air intake duct and solely one or more exhaust ventilation fans are provided.

The ventilation air is sometimes used not only for influencing the climate in the engine room, so mainly as cooling air, but also as supply of combustion air for e.g. the one or more main ship propulsion engines and/or for other engines in the engine room in order to burn the fuel.

On some ships extensive ventilation of one or more rooms other than the engine room is also required, e.g. on cruise ships, car carriers, and on cattle carriers. In the latter the cattle decks are provided with extensive air ventilation in view of animal welfare, e.g. when sailing in warm regions. Here the ventilation itself causes a high energy demand and thus affects the energy consumption of the ship. In view of reduction of fuel consumption, emission of greenhouse gasses and/or other noxious missions, the shipping industry has been experimenting with the use of wind as supplementary energy source.

Ships are known that have, in addition to the fuel engine based main propulsion, an auxiliary sail propulsion system adapted to provide auxiliary propulsion energy for the ship.

For example it is known to provide the ship with a "kite-sail" that effectively provides a towing force for the ship and thereby reduces the fuel consumption.

Other ships are provided (or proposed) with one or more rigid wingsails. Such sails have - in use - a windward surface and a leeward surface. The present invention aims to provide measures that allow to increase the efficiency of a ship according to the preamble of claim 1.

The present invention further aims to provide a ship with an attractive auxiliary sail propulsion system that allows for high energy efficiency.

The present invention achieves one or more of the above aims by providing a ship according to the preamble of claim 1 , which is characterized in that the auxiliary sail propulsion system comprises a sail that is provided with a boundary layer separation control air suction arrangement, wherein the sail is provided with air aspiration apertures in at least said leeward surface of the sail and one or more aspirated air ducts within the sail allowing for air suction through said leeward surface of the sail to control boundary layer separation, and wherein said one or more aspirated air ducts of the boundary layer separation control suction arrangement are in communication with said ventilation air intake duct such that said at least one motor driven ventilation air fan provides for suction of air through the leeward surface of the sail.

In sailing the provision of boundary layer separation control at the leeward side of the sail allows to enhance, often very significantly, the efficiency of the sail. However whilst this is known in theory very little practical use has been made of boundary layer separation control. One example is the experimental sailing ship Alcyone that was sailed by Mr. Jacques

Cousteau. The principle of the two sails of this ship is explained in US4630997 dating from a filing in 1981 , wherein Mr. Cousteau is mentioned as one of the inventors. The present invention now proposes to integrate the engine room ventilation system and/or the ventilation system of one or more rooms other than the engine room (e.g. living spaces of a cruise ship, a car deck, or animal holding deck) with an arrangement for boundary layer separation control by air suction at the leeward side of the sail. Thereby the one or more motor driven ventilation fans serve the double purpose of providing the ventilation air for the room and of providing the suction to obtain air aspiration at the leeward surface of the sail. This integration allows for an increase of the energy efficiency of the ship, and thus allows for reduced fuel consumption and ensuing environmental benefits. In a practical embodiment the sail has an erect and rigid sail body, e.g. a vertically arranged hollow column generally of the same type as proposed by Cousteau and present on the Alcyone, the sail body being provided with shutter controlled aspiration apertures in zones at opposite sides of the sail body, and preferably the sail having one or more orientable flaps at a trailing end of the sail body. The provision of a shutter assembly for the apertures allows to close the apertures at the windward side and to open the apertures at the leeward side, so that air is sucked through the leeward surface of the sail body, e.g. into the central hollow of the column, and then via the ventilation air intake duct into the ventilated room.

In an embodiment the sail body comprises or forms an air duct through which the aspirated air is conveyed to a foot of the sail, by which the sail connects to the ship, the foot being connected to the ventilation air intake duct.

As is known in the art, the sail can comprise an erect rigid hollow column, e.g. of circular or ovoid cross-section, the air being passed through the interior of the hollow column to a foot of the column which is connected to the ventilation air intake duct.

It is noted that the sail may have any of the sail designs disclosed in US4630997, which disclosure is herein incorporated by reference for said purpose. In an embodiment the sail is embodied with an airfoil cross-section, e.g. as a rigid wingsail having a leading end, a trailing end, and curved sail surfaces between the leading and trailing end.

If desired one or more orientable flaps are arranged at the trailing end of the sail.

If desired one or more orientable flaps or an orientable nose member can be arranged at the leading end of the sail. In an embodiment the airfoil cross-section sail is hollow or includes one or more air ducts for the aspirated air from the leeward side of the airfoil.

It is preferred that the hollow sail body or the one or more aspirated air ducts therein, are embodied such that all air aspirated at the leeward face is conducted through the sail body downward to a foot of the sail and then onwards via an ventilation air intake duct to the ventilated room.

In an embodiment the air inlet duct also comprises an additional ventilation air inlet that allows for inletting of air that has not aspirated at the leeward side of the sail, e.g. to allow for all aspiration apertures of the sail to be closed and the ventilation air being let in via an alternative air inlet (e.g. when conditions are such that it is desired to close said aspiration apertures in the sail).

One can envisage that one or more air valves are provided to selectively open or close (a part or parts of) the ventilation ductwork leading to a ventilation fan, e.g. to allow switching between a ventilation airstream from one or more sails on the one hand and one or more additional air inlets on the other hand.

One can envisage that the sail has, in addition to the boundary layer suction aspiration apertures, one or more additional air inlets, e.g. at a top end of the sail, possibly said one or more additional air inlets being provided with a valve to allow for selective opening and (partial) closing of the one or more additional air inlets.

One can envisage that the ventilation system includes a control unit adapted, e.g.

programmed, to monitor one or more parameters of the room or rooms that are ventilated, e.g. temperature, as well as to monitor the aspiration of air at the leeward side of the sail or sails, e.g. based on ventilation fan operation and/or air speed/pressure measurement, and adapted to control the one or more ventilation fans, and possibly adapted to control one or more additional air inlets and/or air outlets in the ductwork between the sail and the room(s) to be ventilated by means of one or more air valves linked to the control unit, so as to allow for a desired ventilation of said room(s) in combination with a desired aspiration of air at the leeward side of the one or more sails in view of the sail propulsion.

It will be appreciated that the present invention is useful on seaborne ships, e.g. commercial cargo ships, oil tankers, product tankers, gas tankers, bulk carriers, cruise liners, cattle carriers, car carriers, etc. The invention also relates to a method according to claim 10 and a method according to claim 1 1 .

The invention also relates to a method of transportation of cattle, wherein use is made of a ship according to the invention. Herein the ship is provided with one or more cattle decks, and the room ventilation system is operated to ventilate one or more of the cattle decks. The ship is then propelled also by the auxiliary propulsion afforded by the sail, and at least a portion of the air for ventilation of the one or more cattle decks is sucked through the leeward surface of the sail for the purpose of boundary layer separation control.

The invention will now be explained with reference to the drawings. In the drawings:

Fig. 1 shows schematically in plan view a ship according to the invention;

Fig. 2 shows schematically in side view a part of the ship of figure 1 ;

Fig. 3a shows schematically a top portion of the sail of the ship of figure 1 ;

Fig. 3b shows schematically a horizontal sectional view of the sail of figure 3a.

Figures 1 and 2 show a wind energy assisted ship 1 , here a seaborne cargo ship, having a hull 2 with a main or upper deck 3, a bridge 4 (here near the stern), and with an engine room 5 in the hull (here at the stern).

In the engine room 5 two main ship propulsion engines 6 of the fuel combustion type, e.g. fuel oil or diesel driven engines, are arranged. In this example each engine 6 directly drives a propeller shaft 7 with a propeller 8. An exhaust 9 is provided for exhaust gasses from the engines 6.

These main ship propulsion engines 6 effectively provide the main propulsion energy for the propulsion of the ship 1 .

The ship 1 also has an engine room ventilation system that is adapted to cause forced ventilation of the engine room 5. This engine room ventilation system comprising at least one ventilation air intake duct 10 and at least one motor driven ventilation fan 1 1 , preferably driven by an associated electric motor. If desired multiple ventilation fans are employed, e.g. when retrofitting an existing ventilation system with the invention, the existing ventilation system fan can be supplemented with one or more additional fans.

In this example, as is preferred, the ventilation fan 1 1 is placed in the ventilation air intake duct 10. The ship 1 further comprises an auxiliary sail propulsion system that is adapted to provide auxiliary propulsion energy for the ship, so that the sail assisted the propulsion by means of the engines 6 allowing to reduce the fuel consumption of the engines 6. Under circumstances the sail may provide all required propulsion energy, but it is more likely that in practical embodiments the auxiliary sail propulsion system will only provide a portion of the propulsion energy.

In this example, the auxiliary sail propulsion system comprises multiple sails 20 that are arranged at various locations on the deck 3 of the ship. Here, by way of example, multiple sails 20 are arranged on the centerline of the ship, but other arrangements, e.g. in a row along one side of the ship, or in two rows, are also possible. For example in a cruise liner one or more sails can be placed on the superstructure of the ship.

It is illustrated, as can be best seen in figures 2, 3a, 3b, that the one or more sails 20 can be embodied as rigid wingsails with an airfoil cross-section.

Each wingsail has an erect rigid sail body 21 with a leading end 22, a trailing end 23, a top 24, and curved sail surfaces 24, 25 between the leading and trailing end. In use one of these surfaces 24, 25 acts as windward surface of the sail whereas the other surface acts as leeward surface of the sail 20. The sail 20 is connected at a foot 20a to the structure of the ship, here to the deck 3.

As is preferred the rigid sail body 21 is pivotable relative to the foot 20a about a vertical axis 26 to allow optimal positioning of the wingsail relative to the wind direction. As is preferred each sail body 21 is rotatable through 360 degrees so that any desired position is possible relative to the wind. A sail positioning drive may be provided (as is known in the art) to rotate or pivot the sail 20 about the axis 26.

The sail 20 shown here is provided with an orientable trailing flap 21 a that is arranged at the trailing end of the airfoil cross-section rigid sail body 21 . The flap 21 a can be adjusted relative to the sail body as is known in the art.

The sail 20 is provided with a boundary layer separation control air suction arrangement allowing to control the boundary layer of air at the leeward side of the sail 20.

The sail 20, here the rigid sail body 21 , is provided with air aspiration apertures 27 (e.g. slots, holes, porous portions, etc.) in the surfaces 24, 25. A shutter device 28, 29 is provided at each surface 24, 25 of the sail 20 allowing to shut selectively the apertures at the windward surface of the sail so that only the apertures 27 at the leeward surface of the sail are open. For example the shutter device comprises a mobile (e.g. pivotal or sliding) shutter plate, e.g. at the outside or inside of the surface through which the apertures extend. Other shutter designs are also possible. For example, e.g. as on the Alcyone, the shutter device may be integrated or combined with the trailing flap.

For example these air aspiration apertures are arranged in one or more vertical strip like zones of the respective sail surface 24, 25.

As can be seen the rigid sail body 21 is embodied as a hollow body that effectively then forms an air duct 21 ' within the sail. The apertures 27 connect the outside of the sail with the internal hollow 21 ' of the rigid body. The hollow interior 21 ' of the sail body 21 is in communication - through the foot 20a having an air passage therein - with the ventilation air intake duct 10, which extends between the sail 20 and the engine room 5.

It will be appreciated that operation of the at least one motor driven ventilation air fan 1 1 now allows for suction of air through the apertures in the leeward surface of the sail body 21 and thereby allows for control of boundary layer separation at said leeward side of the sail.

Instead of the entire rigid sail body 21 being hollow, one can also envisage that the sail is provided - in addition to a rigid sail body forming the leeward and windward surfaces of the sail - with one or more distinct aspirated air ducts, e.g. tubes, within the rigid sail body allowing for air suction through said leeward surface of the sail.

As explained in the Cousteau patent the rigid sail body may even be circular or a simple ovoid in horizontal cross-section to obtain the propulsive energy.

If desired the sail body 21 can be fixed in position relative to the ship, but the provision of a drive for positioning the rigid sail body 21 to adjust the incidence angle of the wind relative to the rigid sail body is preferred. It is illustrated that the air inlet duct 1 1 also comprises an additional ventilation air inlet 13 that allows for inletting of air that has not aspirated at the leeward side of the sail 20, e.g. to allow for all aspiration apertures of the sail or sails 20 to be closed and the ventilation air being let in via an alternative air inlet (e.g. when conditions are such that it is desired to close said aspiration apertures in the sail, or in case of a malfunctioning of the shutter device).

It is illustrated that an air valve 14 can be provided to selectively open or close (a part or parts of) the ventilation ductwork leading to a ventilation fan 10, e.g. to allow switching between a ventilation airstream from one or more sails 20 on the one hand and one or more additional air inlets 13 on the other hand.

One can also envisage that the sail 20 has, in addition to the boundary layer suction aspiration apertures 27 in the side surfaces 24, 25, one or more additional air inlets, e.g. at a top end of the sail 20, possibly said one or more additional air inlets being provided with a valve to allow for selective opening and closing of the one or more additional air inlets of the sail. This e.g. allows to suck in air when all apertures 27 are closed by the shutter devices 28, 29 or as an additional way of entry of air into the sail interior 21 '. One can also envisage that for the purpose of aspiration of air for the purpose of the boundary layer separation control at the leeward side of the sail more air needs to be sucked in (possibly momentarily) then can be sucked in by the one or more fans that cause the air stream into the ventilation intake duct 10. E.g. for such a situation one may provide the sail, e.g. at the top end, with an additional fan for boundary layer separation control air aspiration. This fan can be used to complement (possibly momentarily) the capacity of the one or more ventilation airstream fans, said one or more additional fans of the sail having an exhaust path directly into the atmosphere and not into the ventilation intake duct 10, e.g. outwards at the top as in the Alcyone. One can also envisage that the aspiration of air in view of the boundary layer separation control, results in more air being aspirated through the sail surface than is needed (e.g. temporarily) for ventilation purposes of one or more rooms of the ship. For such a situation an air release of some of the aspirated air via one or more additional air outlets connected to the ventilation air intake ductwork can be provided, e.g. to the atmosphere. For example, the an air release valve and additional air outlet towards the atmosphere can be provided, e.g. combined or integrated in air valve 14. One or more air fans are then placed in the ductwork between the one or more sails and the air release valve.

The ventilation system includes a control unit 30 that is adapted, e.g. programmed, to monitor one or more parameters of the room or rooms that are ventilated, e.g. temperature. The control unit 30 also monitors the aspiration of air at the leeward side of the sails 20, e.g. based on ventilation fan operation and/or air speed/pressure measurement. The control unit 30 is adapted to control the one or more ventilation fans 1 1 , and in this example also adapted to control one or more additional air inlets 13 in the ductwork between the sails 20 and the room 5 to be ventilated by means of one or more air valves 14 linked to the control unit 30, so as to allow for a desired ventilation of the engine room 5 in

combination with a desired aspiration of air at the leeward side of the sails 20 in view of the sail propulsion.

As explained above, the invention also relates to integration of the mentioned sail or sails with the ventilation system of a room aboard the ship other than the engine room. For example on car carriers extensive ventilation of the car decks is required. The same holds for cattle carriers wherein the animal holding decks are extensively ventilated in view of animal welfare.

Claims

C L A I M S

1 . Wind energy assisted ship (1 ) comprising:

- an engine room (5),

- one or more main ship propulsion engines (6) of the fuel combustion type arranged in an engine room, said one or more main ship propulsion engines being adapted to provide the main propulsion energy for the propulsion of the ship,

- a room ventilation system, e.g. an engine room ventilation system or a cargo holding room ventilation system, adapted to cause forced ventilation of a room onboard the ship, said room ventilation system comprising at least one ventilation air intake duct (10) and at least one motor driven ventilation fan (1 1 ), preferably said ventilation fan being placed in said ventilation air intake duct, wherein the ship further comprises an auxiliary sail propulsion system adapted to provide auxiliary propulsion energy for the ship, wherein said auxiliary sail propulsion system comprises:

- a sail (20) having - in use - a windward surface and a leeward surface, characterized in that the auxiliary sail propulsion system comprises a sail (20) that is provided with a boundary layer separation control air suction arrangement, wherein the sail is provided with air aspiration apertures (27) in at least said leeward surface (24, 25) of the sail and one or more aspirated air ducts (21 ') within the sail allowing for air suction through said leeward surface of the sail to control boundary layer separation, and wherein said one or more aspirated air ducts (21 ') of the boundary layer separation control suction arrangement are in communication with said ventilation air intake duct (10) such that said at least one motor driven ventilation air fan (1 1 ) provides for suction of air through the leeward surface of the sail.

2. Ship according to claim 1 , wherein the sail has an erect and rigid sail body (21 ), e.g. a vertically arranged hollow column, the sail body being provided with shutter (28, 29) controlled aspiration apertures (27) in zones at opposite sides (24, 25) of the sail body, and the sail preferably having one or more orientable flaps (21 a) at a trailing end of the sail body.

3. Ship according to claim 1 or 2, wherein the sail body comprises or forms (21 ') an air duct through which the aspirated air is conveyed to a foot (20a) of the sail, by which the sail connects to the ship, the foot having an air passage therein that is connected to the ventilation air intake duct (10).

4. Ship according to one or more of the claims 1 - 3, wherein the sail comprise an erect and rigid hollow column (21 ), e.g. of circular or ovoid horizontal cross-section, the air being passed through the interior of the hollow column to a foot (20a) of the column which is connected to the ventilation air intake duct (10).

5. Ship according to one or more of the claims 1 - 4, wherein the sail is embodied with an airfoil cross-section, e.g. as a rigid wingsail (20) having a leading end (22), a trailing end (23), and curved sail surfaces (24, 25) between the leading and trailing ends, wherein, possibly, one or more orientable flaps (21 a) are arranged at the trailing end of the airfoil cross-section sail.

6. Ship according to one or more of the claims 1 - 5, wherein the sail is an airfoil cross- section sail which is hollow (21 ') and/or includes one or more air ducts for the aspirated air from the leeward side of the airfoil sail, preferably the hollow sail body or the one or more aspirated air ducts therein being embodied such that all air aspirated at the leeward face is conducted through the sail body downward to a foot (20a) of the sail and then onwards via an ventilation air intake duct (10).

7. Ship according to one or more of the claims 1 - 6, wherein the ventilation air intake duct (10) also comprises an additional ventilation air inlet (13) that allows for inletting of air that has not aspirated at the leeward side of the sail (20), e.g. to allow for all aspiration apertures (27) of the sail to be closed and the ventilation air being let in via an alternative air inlet formed by the additional ventilation air inlet (13).

8. Ship according to one or more of the claims 1 - 7, wherein the sail has, in addition to the boundary layer suction aspiration apertures, one or more additional air inlets, e.g. at a top end of the sail, possibly said one or more additional air inlets being provided with a valve to allow for selective opening and closing of the one or more additional air inlets.

9. Ship according to one or more of the claims 1 - 8, wherein the ship is a commercial seaborne cargo ship, oil tanker, product tanker, gas tanker, bulk carrier, cruise liner, car carrier, cattle carrier, or the like.

10. Method of propulsion of a ship according to one or more of the preceding claims, wherein the one or more main ship propulsion engines (6) provide the main propulsion energy for the propulsion of the ship and wherein the auxiliary sail propulsion system provides auxiliary propulsion energy for the ship, and wherein the at least one motor driven ventilation air fan (1 1 ) provides for suction of air through the leeward surface of the sail in order to establish a boundary layer separation control at the leeward side of the sail.

1 1. Method of retrofitting a ship with an auxiliary sail propulsion system, wherein the ship comprises:

- an engine room (5),

- a room ventilation system, e.g. an engine room ventilation system or a cargo holding room ventilation system, adapted to cause forced ventilation of a room (5) onboard the ship, said room ventilation system comprising at least one ventilation air intake duct (10) and at least one motor driven ventilation fan (1 1 ), preferably said ventilation fan being placed in said ventilation air intake duct, wherein the method comprises providing the ship with a sail (20) having - in use - a windward surface and a leeward surface, the sail being provided with a boundary layer separation control air suction arrangement, wherein the sail is provided with air aspiration apertures (27) in at least said leeward surface of the sail and one or more aspirated air ducts (21 ') within the sail allowing for air suction through said leeward surface of the sail to control boundary layer separation, and the method comprises bringing in communication the one or more aspirated air ducts (21 ') of the boundary layer separation control suction arrangement with said ventilation air intake duct (10) such that said at least one motor driven ventilation air fan (1 1 ) provides for suction of air through the leeward surface of the sail.

12. Method or transportation of cattle, wherein use is made of a ship according to one or more of the claims 1 - 9, which ship is provided with one or more cattle decks, and wherein said room ventilation system is operated to ventilate one or more of the cattle decks, and wherein the ship is propelled also by the auxiliary propulsion afforded by the sail, wherein at least a portion of the air for ventilation of the one or more cattle decks is sucked through the leeward surface of the sail for the purpose of boundary layer separation control.