NL2013378B1

NL2013378B1 - Apparatus for exchanging kinetic energy between a flowing fluid and a structure connected to the apparatus.

Info

Publication number: NL2013378B1
Application number: NL2013378A
Authority: NL
Inventors: Willem Van Briemen Johannes
Original assignee: Htp Tech B V
Priority date: 2014-08-28
Filing date: 2014-08-28
Publication date: 2016-09-26
Also published as: WO2016032331A1

Abstract

The invention relates to an apparatus for exchanging kinetic energy between a flowing fluid and a moveable structure connected to the apparatus, the apparatus comprising a channel enclosed by a channel wall connected with the structure, the channel wall being adapted to guide the fluid, at least two substantially identical blades extending within the channel, being moveable within the channel and being connected to an energy converter coupled with the structure, the blades being adapted to perform a recurrent movement in the flow direction with the main plane of the blades substantially perpendicular to the flow direction and against the flow direction with the main plane of the blades substantially parallel to the flow direction, and guides extending from the channel wall into the channel for supporting the blades at a distance from the channel wall during the movement of the blades.

Description

Apparatus for exchanging kinetic energy between a flowing fluid and a structure connected to the apparatus

The present invention relates to an apparatus for exchanging kinetic energy between a flowing fluid and a structure connected to the apparatus, the apparatus comprising a channel enclosed by a channel wall connected with the structure, the channel wall being adapted to guide the fluid, at least two substantially identical blades extending within the channel, being moveable within the channel and being connected to an energy converter coupled with the structure, the blades being adapted to perform a recurrent movement, in the flow direction with the main plane of the blades substantially perpendicular to the flow direction and against the flow direction with the main plane of the blades substantially parallel to the flow direction.

Such an apparatus is attractive as it obtains a highly efficient conversion of the kinetic energy from the fluid to the structure or from the structure to the fluid. The reason for this high efficiency resides in the direction of the blades during the movement wherein thrust is exchanged between the blades and the fluid; during this movement the blades extend substantially perpendicular to the direction of flow of the fluid. This implies that the direction of the pressure between the blade and the fluid is equal or nearly equal to the direction of flow, leading to a complete use of the surface area of the blade so that small apparatuses according to the invention may exchange substantial powers. Another advantage of the movement of resides in the fact that the direction of movement of the blades is substantially parallel to the direction of the flow minimising eddy flows and the losses related thereto.

An apparatus of this kind is disclosed in NL-A-1 039 946. However this prior art apparatus has the disadvantage that the blades are only supported in their centres. Although usually this support is sufficiently stable, the forces encountered by the blades may be large, which could lead to deformation of the blades. This deformation may be irreversible or it may cause jamming of adjacent blades. Further the bearings supporting the blades are heavily loaded.

To avoid or to ameliorate these disadvantages the present invention proposes to provide guides extending from the channel wall into the channel for supporting the blades at a distance from the channel wall during the movement of the blades. These guides provide added support and guidance to the parts of the blades which are furthest from the connection of the blades thus ameliorating the load on the bearings. A preferred embodiment provides the feature that the channel has a circular cross section and that the blades have been arranged symmetrically in the channel. This embodiment provides a symmetric exchange of forces and pressures within the channel to avoid eddy flows and similar disturbing flows.

According to a constructional attractive embodiment the blades each comprise two substantially identical blade parts, separated by a hinge, the axis of the hinge extends in a radial plane in each position of the blades, each blade part is connected by a connection element to shaft journalled to the channel wall, the guides extend in the radial plane in which the hinges extend and the hinges are connected to the guides. This embodiment introduces symmetry within the blades, allowing a simple connection between both blade halves and the shaft which transfers the movement of the blades to the structure.

Preferably the guides each comprise a curved rail, along which a carriage is moveable and that the carriages are each connected to a hinge. Mathematical analyses of the movement of the blades reveals that the hinge between the blades comprises points which execute a circular movement during the recurrent movement of the blades, allowing to use a curved rail with a circular shape. However the ends of the hinge execute a cardioid movement. As the support is most effective at the ends of the hinge, it is preferred that the rail has a cardioid shape, allowing the hinges to be supported at their ends. It is not excluded that the support is embodied otherwise than as a rail, for instance as a groove milled into a plate extending in the radial direction. A further embodiment provides the feature that each of the guides is connected to two carriages and that these two carriages are connected to a single hinge. Preferably these carriages only have a single shaft or pin which is guided by the guide to allow the perform the movement of the discontinuous part of the guides.

Preferably the apparatus comprises an even number of blades, wherein the number of blades is at least four and that adjacent blades are shifted in phase over 180° for their movement. This embodiment allows use of blades having large surface areas as in the position wherein the blades extend perpendicular to the direction of flow, and the blades would coincide, mutual interference between adjacent blades is avoided.

Preferably the apparatus comprises six blades. The allows the blades to close the major part of the cross section of the channel when the blades extend preferably perpendicular to the flow direction simultaneously. A constructional attractive embodiment provides the feature that each of the connection elements is connected by a hinge to the blade part at one of its ends and is connected by a hinge at its other end to a shaft extending substantial tangentially and which is connected to an energy converter and that the axis of the hinges extend parallel. It is noted that this embodiment diverges slightly from the embodiments discussed hitherto in that the movement is different; of course symmetry is maintained but the analyses of the movement is different as it forms a rotation around an axis rather than a composite movement as in the preceding embodiments.

The construction is simplified further if the connection elements each comprise a rod, at both sides of which a hinge has been provided.

This is even more the case if the rod extends parallel to the plane of the blade part.

According to another embodiment the rod extends in a sector shaped cavity provided in the blade part. This latter embodiment is less attractive for liquids such as water, due to the movement of the rod within the confined cavity.

Of course it is possible to have the rods extend next to the relevant blade part, but it is also possible that the connection elements each have the U-shaped configuration of which the legs extend at either side of the blade part.

As stated before, the apparatus according to the invention can be used to the conversion of kinetic energy from a flowing fluid to the kinetic energy of a moving structure, but also for the conversion of kinetic energy from a moving structure to the kinetic energy of a fluid. This implies that energy conversion in two directions is possible. Often a further conversion of energy is required, such as into electrical energy or from electrical energy. Hence a preferred embodiment proposes to couple the connection elements each to a first part of an energy converter and to connect the blade parts each to the second part of the energy converter. The energy converter may be an electrical machine, which can function as a generator or as a motor allowing energy conversion in both directions. It is however also possible to This embodiment provides an integration of the electric machine into the apparatus itself, avoiding the use of electrical machines located elsewhere, and hence providing a compact structure.

Another embodiment provides the feature that the shafts are mutually connected and that the shafts are connected to the power converter. This embodiment avoids the complicated construction of the preceding embodiment, but it requires more space. Further the energy converter need not be an electrical machine, as it may be formed of a machine comprising pistons and cylinders such as an engine or a compressor.

As stated before, an attractive application of the invention resides in the conversion of kinetic energy of flowing water to kinetic energy of a rotating shaft, which can be used for water turbines. A similar application of the invention resides in the propulsion of ships. Hence an embodiment proposes that the apparatus is dimensioned for converting kinetic energy of a rotatable shaft into kinetic energy of vessel connected to the apparatus and that the rotatable shaft of the apparatus is connected to a combustion engine or to an electric motor.

The two applications mentioned above relate to the exchange of kinetic energy to and from water. Another application resides in the exchange of kinetic energy to and from air. A first application is in ventilators, but another, presumably more important application resides in wind turbines. Consequently a preferred embodiment provides an apparatus of the kind referred to above which is dimensioned for converting kinetic energy of wind into kinetic energy of a rotatable shaft.

Another preferred embodiment provides the feature that the rotatable shaft is coupled to an electric generator. A major advantage resides in strong reduction of currents in the direction deviating from the main direction of flow. This implies that adjacent flows generated by the apparatus according to the invention will interfere less than before. This will not only count for situations wherein the apparatus according to the invention is used for generating flows, but also in situations wherein the kinetic energy of flows is converted into kinetic energy of a rotating shaft, wherein the lack of flows deviating from the main direction of flow will appear from the flows leaving the apparatus. This effect allows to combine a number of apparatuses in their immediate vicinity. A preferred embodiment of hence provides the feature that the rotatable shafts of the apparatuses extend mutually parallel, and that the distance between the channel walls of adjacent apparatuses is smaller than the width of the channel walls.

The apparatuses do not necessarily have to be arranged with their centres in the same plane, but due to constructional reasons it can be attractive when the blades of the apparatuses in their position perpendicular to the flow direction, extend substantially in the same plane. This allows to construct ‘energy walls’ with large numbers of apparatuses being arranged in the same structure. Such walls may be constructed in the sea, preferably in locations wherein tides provide for alternating flows, but also in locations where winds are prevailing to allow large amounts of energy to be generated by a single structure.

Of course it is possible to connect each of the apparatuses to a separate energy converter, but it is usually attractive to connect al apparatuses to the same energy converter. However when the number of apparatuses is large, it may be advantageous to divide the number of apparatuses into a number of groups wherein the apparatuses belonging to a group, are connected to the same energy converter.

Subsequently the present invention will be elucidated with the help of the following drawings wherein :

Figure 1: is a diagrammatic perspective view of an apparatus according to the prior art;

Figure 2: is a view similar to figure 1, wherein the guides according to the invention have been provided;

Figure 3: is a cross sectional view over a the radial plane of a hinge of a second embodiment of the invention;

Figure 4: is a cross sectional view of a

Figure 5: is a diagram of an array of apparatuses according to the invention.

Figure 1 displays a channel of which the wall 1 is represented by wall pieces la and connecting bands lb only, to allow to show other parts. Figure 2 shows a cross sectional view of this channel with the channel wall 1. In the present case the channel has across section with the shape of a regular twelvefold polyhedron, approaching the cross section of a circle. This shape has been chosen to allow six blades 2 to fit into the channel. The number of six blades combines also well with channel with a round cross section or with a hexagonal cross section.

The blades 2 have been arranged symmetrically in the channel. Of course other numbers of blades could have been provided such as four blades or eight blades, wherein the shape of the cross section of the channels would have to be adapted to the number of blades. As adjacent blades are arranged with a mutual phase angle of 90 °, the number of blades has to be even to avoid mutual interference. Figure 1 shows three blades 2a extending substantially perpendicular to the direction of flow and thee blades 2b extending substantially parallel to the direction of flow. Each of the blades a comprises a hinge 4, separating each blade 2 in two equal blade halves 5a, 5b, as caused by the fact that the hinge 4 extends in a radial plane.

Adjacent to the wall 1 extends six shafts 6, which are journalled in bearings 7 connected to the wall 1. The shafts 6 extend in the tangential direction to the wall and the shafts are located between the blades 2. In the present embodiment the shafts are located within the walls of the channel, but it is equally possible to have the shafts extend outside the channel walls 2. At each end of the shafts a universal joint 8 has been provided and a rod 9 is connected to each of the universal joints 8. The free end of each of the rods 9 is connected to another universal joint 11 which is connected to the centre of the hinge 4. In the depicted embodiment the rods each extend parallel to one side of the blade half 5. To make the blades follow the movements of the rods and to make the rods follow the movements of the blades a connection part 12 has been provided to the rods, which engages the edge 13 of the blades. There are however alternatives obviating the connection part. In one embodiment, which is not disclosed in the drawings the rods 9 are replaced by U-shaped parts of which the bridge part is connected to the universal joint at the side of the shafts, while the legs of the U-shaped parts extend at either side of the blade halves. According to another embodiment the blade parts each have a sector shaped cavity in which the roads extend. The kinetic energy which has been transferred to the shafts which has been transferred from the shafts, has to be transferred to and from an energy converter, which is not depicted in the drawings. The connection may take place via gears 14 located on the shafts and which are in engagement with gears connected with the energy converter. Other constructions for these transfers are however not excluded.

According to the invention a guide rail 15 has been provided, which is depicted in figure 2. The edges of the hinges 4 have carriages 15a at their ends which slide along the guide rails to provide the extra support. As figure 2 shows only a cross section, only two rectangles are visible which represent the rail, while further two smaller rectangles are shown which represent the carriages connected to the ends of the hinges and being guided along the guide rails 15. The guide rail has the shape of an epicycloid. An epicycloid is a line composed of the sum of two circular lines having different radii. The epicycloid has a discontinuity, for which provisions have to be made to allow the carriages 15 to follow the discontinuity of the guide rails 15. Please note that the guide rail is only visible in figure 2 as figure 1 shows a prior art apparatus.

Figure 3 shows an embodiment wherein the energy converter has been incorporated into the blades. Figure 3 shows only a single blade 2 having two blade halves 5a, 5b, but it will be clear that the each of the blades will have a similar structure. In the drawing like elements have been designated with like reference numbers.

In each of the blade halves 5a, 5b a sector shaped cavity 31 has been provided. In the blade halves 5a, a coil 32 surrounding the cavity 31 has been wound. The coil 32 may encompass the complete angle of the sector shaped cavity 31but may also extend over a part of the cavity only. The rods 9 extend for a part or for the whole of their length within the cavity 31. Each of the rods 9 is connected with an anchor 33 having the shape of a sector of a ring and extending concentrically with the centre of the blades. The anchor 33 is magnetic, either in the form of a permanent magnet or in the form of an electromagnet. The combination of each of the coils 32 and the magnet 33 coupled with said coil 32 forms an electric machine, which can work as a generator or as an electric motor. The coils 32 are connected with wires not depicted in the drawings to rectifiers or other electric equipment not depicted in the drawings allowing said combination to perform its function as a generator or as an electric motor.

The embodiment descried above has the drawback that the construction thereof is rather complicated. Hence another embodiment was devised having an easier construction. This alternative embodiment is shown in figure 4. In this figure, wherein similar parts have the same reference numbers as similar parts in the preceding embodiments, the shafts 6 and the universal joints have been removed. Rather shafts 16 have been provided which extend perpendicular to the channel wall 2. These shafts 16 end in gear boxes 17, which have been fixed to the channels walls 2, by means not depicted in the drawing. The number of shafts and gear boxes is equal to the number of blades, just as in the preceding embodiment. Adjacent gear boxes 17 are connected by shafts 18, wherein the gear boxes are constructed such that the shafts 18 all rotate in the same direction in relation to the centre of the channel. The shafts 18 are each connected to a hinge 4, such that rotation of a shaft 18 leads to rotation of the hinge 4, relative to the centre of the shafts 18. Rotation of the hinges 4 leads to ration of the blade halves 5a, 5b, just as in the preceding embodiments. However the presence of the shafts 18 requires teach of the blades halves to be parted to take account of the location of the shafts.

The parts of the blade halves 5a, 5b which are connected with the rods 9 in any of the ways described above, are controlled by the rods 9, but the parts of the blade halves 5a, 5b at the inner location, must be connected to the outer parts of the same blade halve 5a, 5b to allows these inner blade halve parts to follow the required movement. The rods 9 serve in this embodiment only for control of the angle of the blade halves relative to the hinge 4, so that the can be connected to the channel wall 1 by simple ball joints 10. Further this embodiment discloses a different shape of the blades 5a, 5b, wherein the shape is adapted to approach the full cover of the cross section of the channel. It is however also possible to use round blades as in the preceding embodiment.

For the function, the movement, the performance and the theoretical background, reference is made to the Dutch patent NL-C-1039946 and the Dutch patent application NL-A-1039946, which are incorporated herein by reference.

Finally figure 5 shows an diagram of an array of seven apparatuses according to the present invention which are united in the shape of a tree. This shape makes this embodiment in particular suitable for application for conversion of wind energy into mechanical and further into electrical energy.

This embodiment comprises a mast 20, onto which a carrier piece 21 has been provided. This carrier piece 21 carries seven apparatuses 22 according to the invention. Herein each apparatus 22 has the shape of a twelvefold polyhedron allowing these apparatuses to be combined in the pattern depicted, while providing space for the energy converters 23 interleaved in the pattern. This embodiment provides a wind turbine having an excellent efficiency, and having an agreeable appearance, while further the noise level generated by the apparatuses is substantially lower than the noise level generated by wind turbines of more common types, as caused by the lower speed of the blades.

It will be clear that other shapes could be used. Further application in flowing water is not excluded, if the apparatuses have been dimensioned for said application.

Claims

A device for exchanging kinetic energy between a flowing fluid and a movable structure connected to the device, comprising: - a channel enclosed by a channel wall connected to the structure, the channel wall being adapted to guide the fluid; - at least two vanes extending substantially within the channel, arranged in the channel and substantially mutually equal blades, which are connected for transmitting movement to at least one energy converter coupled to the structure; - wherein the blades are adapted to perform a repetitive movement; - with the main surface of the blade substantially transverse to the flow direction in the flow direction; and - with the main surface of the vane substantially parallel to the flow direction against the flow direction, characterized by guides extending from the channel wall into the channel for supporting the blades remote from the channel wall during the movement.

Device as claimed in claim 1, characterized in that the channel has a round cross-section and that the blades are placed symmetrically in the channel.

Device as claimed in claim 1 or 2, characterized in that - the blades each comprise two identical blade blades that are separated by a hinge, - that the axis of the hinge extends in a radial plane in each position of the blades; - that each of the blade blades is connected by a connecting element for rotation to an axle piece mounted on the channel wall; - that the guides extend in the radial plane in which the hinges extend; and - that the hinges are connected to the guides.

Device as claimed in claim 3, characterized in that each of the conductors comprises curved rails along which a carriage is movable and that the carriages are each connected to a hinge.

Device as claimed in claim 4, characterized in that each of the conductors is connected with two carriages and that the two carriages are connected with the same hinge.

Device as claimed in claim 3, 4 or 5, characterized in that the device comprises an even number of vane blades, that the number of vane blades is at least four and that neighboring vanes are phase-shifted with respect to their movement through an angle of 180 ° .

Device as claimed in claim 6, characterized in that the device comprises six blades and that the channel at the location of the blades is substantially hexagonal.

8. Device as claimed in claims 3-6, characterized in that each of the connecting elements is connected at one of its ends by a hinge to a blade blade and at its other end is connected by a hinge to a substantially tangentially extending shaft connected to the at least one energy converter is connected and that the axes of the hinges connected to a connecting element extend parallel.

Device as claimed in claim 8, characterized in that the connecting elements each comprise a rod, on both sides of which a hinge is arranged.

Device as claimed in claim 9, characterized in that the rod extends parallel to the plane of a blade, but next to the blade.

Device as claimed in claim 9, characterized in that the rod extends through a circular sector-shaped cavity arranged in the blade.

Device as claimed in claim 9, characterized in that the connecting elements each have a U-shaped configuration, the legs of which extend on either side of the blade blade.

Device as claimed in any of the claims 3-12, characterized in that the connecting elements are each coupled to a first part of the energy converter and that the blade blades are each coupled to a second part of the energy converter.

Device as claimed in any of the claims 3-12, characterized in that the shafts are mutually coupled and that the shafts are coupled to the energy converter.

Device according to one of the preceding claims, characterized in that the device is dimensioned for converting the kinetic energy of flowing water into the kinetic energy of a rotatable axis.

Device as claimed in any of the claims 1-14, characterized in that the device is dimensioned for converting kinetic energy of a rotatable axis into the kinetic energy of a vessel connected to the device and propelled by the device and that the The rotatable axis of the device is connected to a combustion engine or an electric motor.

A device according to any one of claims 1-13, characterized in that the device is dimensioned for converting kinetic energy from wind into the kinetic energy of a rotatable axis.

Device as claimed in claim 15 or 17, characterized in that the rotatable shaft is coupled to an electric generator.

Combination of a number of devices according to one of the preceding claims, characterized in that the rotatable axes of the devices extend in parallel and that the distance between the channel walls of neighboring devices is smaller than the width of the channels.

Combination according to claim 19, characterized in that the blades of the devices extend substantially in the same plane with their position transverse to the flow direction.

A combination according to claim 19 or 20, characterized in that the devices are all connected to the same energy converter.