WO2018178723A1

WO2018178723A1 - Apparatus for generating electricity

Info

Publication number: WO2018178723A1
Application number: PCT/GB2018/050889
Authority: WO
Inventors: Alexander Troels HOST
Original assignee: Urdiamonia Limited
Priority date: 2017-03-30
Filing date: 2018-03-29
Publication date: 2018-10-04
Also published as: GB201705072D0; GB2560955B; GB2560955A

Abstract

A partially immersed structure (10] equipped with a power generation system (a so-called "run-of-river hydropower system] is disclosed. The structure has a wall (24] in contact with water (30] in which the structure (10] is immersed. In the wall, there is a flow passage that is, during use of the structure, at least partially below the waterline. There is a turbine (36] within the flow passage (20] and a shaft (34], extending from the turbine, through the wall. A generator is connected to the shaft on the opposite side of the side wall to the turbine. Typically the structure may be a hull of a boat or a fixed structure, such as a quay.

Description

Apparatus for generating electricity

This invention relates to apparatus for generating electricity.

There is an increasing demand for access to electrical power to be supplied to locations where connection to the conventional electrical supply grid is not practical or is not desired. This can be the case for people living in places that do not have well-developed and reliable electrical supply infrastructure, and also to people living in locations that the conventional infrastructure does not serve, such as in houseboats.

The recognised solution to the problem of providing electricity to such locations is to use a generator powered by a petrol or diesel engine. However, this does not help where the supply of fuel is unreliable or unaffordable, and has the undesirable by-product of producing significant atmospheric and noise pollution. Extraction of energy from flowing water to generate electricity is widely practiced. On a commercial scale, this generally involves erecting a barrier to natural water flow (e.g., damming a river or creating a tidal barrage] and extracting energy from water that flows through the barrier as a result of the establishment of a head of water on opposite sides of the barrier. These schemes require significant capital investment and can have detrimental effects on flora and fauna that inhabit the water.

An alternative approach is to use a so-called "run-of-river" generation system. This involves siting a turbine within naturally flowing water, with minimal disruption to the water flow. It should be understood that the principle is not limited to gravitational flow of water within a river - it is equally applicable to situations where the flow arises from tidal cycles. Known run-of-river hydropower systems typically use a turbine that is external to a floating vessel. However, this is not always an acceptable solution because it can create an obstruction to passing river traffic and can be hazardous to wildlife. It is also known to install a turbine in a duct running from the bow to the stern of a vessel, such as in the disclosure of GB-A-2 521 679, but such an arrangement is more suited for use in a vessel that is under way than to a stationary vessel, where the flow of water is typically slower, and maintenance is difficult because of the difficulty in gaining access to the turbine.

An aim of this invention is to provide an improved run-of-river power generation system that overcomes, or at least ameliorates, the disadvantages of known systems.

To this end, from a first aspect, this invention provides a partially immersed structure equipped with a power generation system. The structure may have a wall in contact with water in which the structure is immersed, wherein, in the wall, there is a flow passage that is, during use of the structure, at least partially immersed; and there being a turbine within the flow passage and a shaft, extending from the turbine, through the wall; and a generator connected to the shaft on the opposite side of the side wall to the turbine.

The turbine is driven by water entering the flow passage as it flows past the structure. Since the turbine is in a flow passage, there is no risk of it impeding river traffic. Maintenance of the system is facilitated by the generator being on the dry side of the wall and the turbine being in an accessible position. The speed of flow within the flow passage may be greater than the speed of flow of water surrounding the structure, which can be beneficial to its ability to transfer energy to the turbine. In typical embodiments, the structure is a floating structure, such as a hull of a boat, and most typically, a houseboat, floating home or other form of floating building or structure. In such embodiments, the flow passage may advantageously extend between a side wall and one or other of the bow and the stern of the vessel. As the passage has openings at each of its two ends, this may mean that one opening is generally transverse to the typical direction of flow of water and the other faces generally towards or away from the typical direction of flow of the water. This arrangement can cause the speed of flow within the flow passage to be higher (significantly higher] than the speed of flow of water past the vessel.

In embodiments where the structure is a floating structure, the generator is typically located within the structure - for example, within the hull of a boat. This allows convenient access to the generator e.g., for maintenance. In this arrangement, leakage that might occur, for example past a seal that is associated with a shaft connecting the turbine and the generator, can be accommodated by a bilge water control system of the hull.

Alternatively, the structure may be a fixed structure such as a wall, a pier, a culvert or otherwise. In preferred embodiments, the turbine is a waterwheel, for example, a Pelton wheel. However, its form is not central to the invention: the requirement is that it can extract energy from flowing water within which it is partially or wholly immersed. Although waterwheels may not be the most efficient form of turbine, they have the advantage of being tolerant of a wide variety of water flow conditions and have only minimal effect upon the surrounding environment The waterwheel typically comprises a plurality of blades that extend radially for a hub, the hub being carried on the shaft for rotation with it. The waterwheel is arranged such that a blade extending downwardly from the hub is partially immersed in water. Water flowing past the structure will enter the recess and make contact with the immersed blades, which creates a couple about the shaft which urges the waterwheel, and the shaft connected to it, into rotation. (Of course, as the waterwheel rotates, successive blades will enter and leave the water.]

Alternatively, the turbine may be a Turgo turbine.

In a typical embodiment, during normal use, the shaft has an axis of rotation which is generally horizontal. However, embodiments may also provide a turbine with an axis of rotation which is generally vertical.

In embodiments of the invention, the flow passage may be open, for example, being constituted by a recess in a wall. Alternatively, the flow passage may be partially wholly or partially enclosed such that the turbine is contained within a flow duct For example, the flow passage may be constituted by a recess that is at least partially covered by a partition plate that defines a flow channel between itself and a back wall of the recess and openings adjacent to the partition plate. In such an arrangement, the turbine is typically between the partition plate and the back wall. Alternatively, the flow passage may be a tubular duct. Openings of the flow passage may be covered with a mesh or other filtration arrangement to prevent debris entering the flow channel. Openings of the flow passage may be provided with closures that can be operated to isolate the flow channel from water in which the structure is immersed.

From a second aspect, this invention provides a power generating system comprising a first structure that is a floating structure embodying the first aspect of the invention and a second structure that is a fixed structure embodying the first aspect of the invention.

For example, the first structure may be a hull of a boat and the second structure a pier against which the boat is moored. Interaction between the structures can result in a system that is more effective than the two structures operating independently (although independent operation is also possible].

Advantageously, at least one opening of a flow passage of the first structure is located adjacent to an opening of a flow channel of the second structure.

Embodiments of the invention will now be described in detail, by way of example, with reference to the accompanying drawings, in which:

Figures 1 and 2 show, diagrammatically, a turbine installed in a vessel in an embodiment of the invention;

Figures 3 and 4 show a duct having openable sluices to control water flow; and

Figure 5 is a cross-section in a horizontal plane that shows an alternative embodiment of the invention.

With reference to the drawings, Figure 1 shows a section through a part of a boat hull 10 and Figure 2 is a side view of the same hull. This particular example is a re-enforced concrete boat hull for a house boat, but is equally applicable to other types of hull or structure.

The hull 10 comprises a base 12 with upwardly extending side walls 14. The side walls 14 extend generally from bow to stern of the hull 10, and, when the boat is moored, water flows along the side walls, as a result of the flow of a river, of tidal flow, or a combination of these and possibly other sources of flow. A recess 20 is formed in a side wall 14. In this embodiment, the recess has a flat base 22, and a back wall 24. The back wall 24 is approximately parallel to parts of the side wall 14 adjacent to the recess 20, but is displaced from it in a direction into the hull 10. The back wall 24 is connected by diagonally extending connecting walls 26 to the parts of the side wall 14 adjacent to the recess 20.

When the boat is afloat and normally loaded, the waterline 30 is such that the recess is under water for about half of its depth.

A waterwheel 32 is carried on a rotatable shaft 34 that extends through the back wall 24 at a height above the normal waterline 30. The waterwheel 32 includes a fixed to the shaft, the hub carrying a plurality of blades 36 that extend radially from the shaft 34.

The shaft 34 extends through a hole in the back wall 24 to pass into the interior of the hull 10, where it is carried on bearings such that it can rotate about an axis that is approximately horizontal when the boat is floating normally, and which is as near as possible at right angles to the direction of flow of water passing the boat. The hole is positioned above the waterline 30. Within the hull 10, the shaft is connected to a mechanical drive input of an electrical generator (not shown].

As water flows past the boat, the flow follows the diagonally extending connecting walls 26 such that it is led into the recess 20. There, it makes contact with immersed parts of the blades 36 of the waterwheel 32. This applies a force to the blades which acts as a couple about the hub, which is manifest as a torque on the shaft 34. Provided that the torque exceeds any load on the shaft as applied by the generator and friction, the shaft will rotate, with the result that the generator creates an electrical output

The output from the generator could be used to power a load directly. However, in many cases, it is advantageous to use it to charge a battery and the battery is then used to drive working loads. This allows useful energy to be generated when no load is being driven, and allows loads to be powered when there is no water flow (particularly in cases where the flow relied upon is tidal].

A modification to this system is shown in Figures 3 and 4. In this embodiment, a lower slot 40 extends in the base 12 within an extension of the plane of the side wall 12 across the opening of the recess 20. An upper slot 42 extends across the opening of the recess 20 in an outwardly-projecting extension 44 of the side wall that passes across an upper part of the recess 20. The upper slot 42 opens upwardly from the side wall 12. Each slot extends a short distance into the side wall 12, and a respective vertical groove 48 in the side wall 12 interconnects the lower and upper slots 40, 42 at each of their ends.

In normal use, a partition plate 46 is located centrally within the slots 42, 44. The partition plate 46 extends through approximately the middle 50% of the length of the slots 42, 44. This creates a flow channel 54 between the partition plate 46 and the back wall 24 that has openings 50 to the recess adjacent to the diagonally extending connecting walls 26. Thus, water flowing past the hull can enter through one of the openings 50, pass along the flow channel 54 where it interacts with the turbine (not shown in Figures 3 or 4] and then leave by the other opening 50. The flow channel 54 acts to direct the water to maximise the efficiency of its interaction with the water wheel. Optionally, the openings may be covered by a mesh or other barrier to prevent debris from entering the flow channel 54. It is also possible to slide sluice plates (not shown] through the open upward slot 42 to close the openings 50. Each sluice plate abuts one vertical edge of the partition plate 46 and enters one of the grooves 48. The sluice plate carries seals that ensure its engagement with the partition plate 46, the slots 42, 44 and the groove 48 watertight This isolates the flow channel 54 from the water flowing past the hull. This can be used to prevent operation of the turbine and generator when it is not required or to enable maintenance to be carried out

Figure 5 shows an alternative embodiment of the invention in which turbines installed in a vessel cooperate with a turbine installed in a pier 56 adjacent to which the vessel is moored.

In the embodiment of Figure 5, two turbines are located in a hull 58 of the vessel, each being a vertical axis Turgo turbine 60, 60' (although other types and arrangements of turbine may be used in other embodiments]. Each turbine 60, 60' is located within a respective water flow duct 62, 62'. Each flow duct 62, 62' opens to a side wall 64 of the hull and to a respective end wall 66, 66' of the hull below the waterline. Thus, each flow duct 62, 62' typically interconnects a side wall and one or other of the bow and the stern of the hull 58. Adjacent to the openings of the end walls 66, 66', the flow ducts 62, 62' extend to the respective turbine 60, 60' in a direction that is approximately parallel to the flow of water past the hull (which may be in a constant direction as in the case of a river or may reverse where flow occurs as the result of tides]. Between the respective turbine 60, 60' and the openings in the side wall 64 the flow ducts 62, 62' extend in a direction that is approximately 45° to the flow of water past the hull. It will be seen that the orientation of the flow ducts 62, 62' is such that one of their openings in the end walls 66, 66' faces directly into the flow of water passing the hull 58 to maximise the pressure of water entering the flow duct 62, 62'.

Adjacent to each opening, a respective set of gates 70 is located within the of the flow ducts 62, 62'. The gates 70 can be opened or closed to allow or prevent flow of water within the of the flow ducts 62, 62'.

When the gates are open, water flowing past the hull 58 will enter one opening of each flow duct 62, 62', move past the turbine 60, 60' urging it to rotate, and leave by the other opening.

This vessel is intended to be moored with the side wall 64 closely adjacent to a pier 56. (The distance between the hull 58 and the pier 56 is somewhat exaggerated in Figure 5.] The pier 56 includes a flow channel 70. The flow channel 70 opens to two openings below the waterline spaced apart along the direction of water flow past the pier. Adjacent to the openings, end parts of the flow channel 70 extends in a direction that is approximately 45° to the flow of water past the pier. Between the end parts, an intermediate part of the flow channel 70 extends in a direction that is approximately parallel to the flow of water past the pier. A horizontal axis waterwheel 72 is located within the intermediate part of the flow channel 70. Water flowing within the flow channel 70 will urge the waterwheel 72 to rotate. Each turbine 60, 60' and the waterwheel 70 is connected by a shaft to a respective electrical generator (not shown] such that their rotation can cause electricity to be generated. In the case of the turbines 60, 60', the shaft and axis of rotation is vertical and the generator is located in the hull 58 of the vessel typically above the waterline. The turbines 60, 60' are each separated from their respective generator by a wall through which the shaft passes, there being a water-resistant seal in the wall to inhibit ingress of water to the hull 58. In the case of the waterwheel, the generator is typically located behind a wall of the pier 56 that defines the flow channel 70. There is a water-resistance seal in the wall through which the shaft passes to resist passage of water through the wall to the generator. In an alternative embodiment, the turbines 60, 60' may be operable to rotate about a horizontal axis. In this arrangement, the shaft extends horizontally through 58 the hull of the vessel and the generator is located within the hull.

The turbines 60, 60' of the vessel and the waterwheel 70 of the pier 56 can operate independently of one another. However, it is intended that they operate cooperatively. To achieve this, the vessel is moored with its hull 58 closely adjacent to the pier 56 such that each of the openings in the side wall 64 of the flow ducts 62, 62' lies adjacent to a respective opening of the flow channel 70 within the pier 56.

As shown in Figure 5, water leaving the upstream flow duct 60 is directed into the adjacent upstream opening of the flow channel 70 within the pier. Likewise, water emerging from the downstream opening of the flow channel 70 is directed into the opening of the downstream flow duct 62'. This results in enhanced flow through the turbines 60, 60' and the waterwheel 70 as compared with the turbines 60, 60' of the vessel and the waterwheel 70 of the pier operating independently of one another.

Claims

1. A partially immersed structure equipped with a power generation system, the structure having a wall in contact with water in which the structure is immersed, wherein, the in the wall, there is a flow passage that is, during use of the structure, at least partially below the waterline; and there being a turbine within the flow passage and a shaft, extending from the turbine, through the wall; and a generator connected to the shaft.

2. A structure according to claim 1 that is a floating structure

3. A structure according to claim 2 that is a hull of a boat.

4. A structure according to claim 3 that is a hull of a houseboat.

5. A structure according to claim 3 or claim 4 in which the flow passage extends between a side wall of the hull and one or other of the bow and the stern of the hull.

6. A structure according claim 1 that is a fixed structure

7. A structure according to claim 6 that is a wall, a pier or a culvert.

8. A structure according to any preceding claim in which the turbine is a waterwheel.

9. A structure according to claim 8 in which the waterwheel comprises a plurality of blades that extend radially for a hub, the hub being carried on the shaft for rotation with it.

10. A structure according to claim 8 in which the waterwheel is arranged such that a blade extending downwardly from the hub is partially immersed in water.

11. A structure according to any preceding claim in which, during normal use, the shaft has an axis of rotation which is generally horizontal.

12. A structure according to any one of claims 1 to 10 in which, during normal use, the shaft has an axis of rotation which is generally vertical.

13. A structure according to any preceding claim in which the flow passage is constituted by a recess in a wall.

14. A structure according to any preceding claim in which the flow passage is wholly or partially enclosed such that the turbine is contained within a flow duct.

15. A structure according to claim 14 in which the flow passage is constituted by a recess that is at least partially covered by a partition plate that defines a flow channel between itself and a back wall of the recess and openings adjacent to the partition plate.

16. A structure according to claim 15 in which the turbine is between the partition plate and the back wall.

17. A structure according to any preceding claim in which openings of the flow channel are covered with a mesh or other filtration arrangement to prevent debris entering the flow channel.

18. A structure according to any preceding claim in which openings of the flow channel are provided with removable closures to isolate the flow channel from water in which the structure is immersed.

19. A structure according to any preceding claim having a plurality of turbines each in a respective flow channel.

20. A structure according to claim 19 in which each turbine is connected to drive a respective electrical generator.

21. A power generating system comprising a first structure according to any one of claims 1 to 5 or any claim dependent therefrom located adjacent to a second structure according to claim 6 or claim 7 or any claim dependent therefrom.

22. A power generating system according to claim 21 in which the first structure is a hull of a boat and the second structure is a pier against which the boat is moored.

23. A power generating system according to claim 22 in which at least one opening of a flow passage of the first structure is located adjacent to an opening of a flow channel of the second structure.