GB2372783A

GB2372783A - Turbine means to generate energy from wind and water on a sailing vessel

Info

Publication number: GB2372783A
Application number: GB0029189A
Authority: GB
Inventors: Peter James Anderson
Original assignee: ECLECTIC ENERGY Ltd
Current assignee: ECLECTIC ENERGY Ltd
Priority date: 2000-11-30
Filing date: 2000-11-30
Publication date: 2002-09-04
Anticipated expiration: 2020-11-30
Also published as: GB0029189D0; GB2372783B

Abstract

A generator has interchangeable wind (10, Figure 1) and water 14 turbine assemblies, and drive means 15 selectively connected to a drive shaft 2 that transmits torque to a generator 3 or other energy conversion device which is pivotably mounted 13 on a sailboat for immersion of the turbine in wind or water flow as required. The mounting arrangement may include a yaw arm 5, vertical tube 23, and brackets 22 and 26 attached to the sailboat. The bracketry is releasably mounted to the vertical tube 23, and the yaw arm 5 can rotate and slide about the vertical tube to allow positioning of the turbine in either air or water flow. The energy conversion device may be an alternator, pump or friction mill, and the drive shaft 2 may be flexible or telescopic and pass though the centre of the vertical tube 23. The orientation of the yaw arm may allow furling of the wind turbine at high wind speeds. A lanyard may be included to allow deployment and recovery of the machine, and to set the operating depth of the impeller.

Description

COMBINED WIND AND WATER GENERATOR This invention relates to a combined wind and water generator which can be easily reconfigured to harness the kinetic energy in either a wind stream or a water stream in order to produce electricity.

The device is designed primarily for use aboard cruising yachts where the wind mode is operated in harbour or at anchor, and the water mode operated when the yacht is under sail or at anchor in flowing water.

The benefits of dual mode systems are that they confer on the owner greater potential for energy conversion than is possible with a single source system. This is because the airstream intercepted by a yacht's sail when it is sailing is usually many times the area of the airstream intercepted by a typical wind turbine. In a given wind speed, therefore, the energy conversion potential is usually far greater when the yacht is under sail and a water generator is deployed.

The electrical energy produced is used to charge yacht batteries. This device is also capable of prolonged operation either in wind mode or water mode, rendering it suitable for standalone wind applications or pico-hydro applications.

Renewable energy devices have long been used aboard cruising yachts. They tend to be terrestrial designs which have been marinised. The wind machines are usually direct drive, horizontal axis, upwind machines, either mounted on a pole or suspended in the rigging.

Water generators can be direct drive and submersible, deployed by towing them with a flexible umbilical tube or they can be mounted on a pantograph. More usually water generators are non-submersible and incorporate a weighted impeller driving a deckmounted alternator via a long towrope.

Hybrid machines exist which are capable of operation in both wind and water mode. These are characterised by the difficulty experienced in changing from one mode to the other.

Hand tools are required to perform the change, which entails major reconfiguration of the system elements. In addition, the alternator and its electrical connections must be demounted and repositioned.

The object of this invention is to make the benefits of a dual-mode system available to the operator in a truly practical form. The change from wind mode to water mode is accomplished in seconds without the use of tools, and without demounting the major system element, i. e. the alternator or dynamo and its electrical connections.

Accordingly, this invention provides a system which uses vectored transmission elements in conjunction with a drive shaft in order to deliver torque to an alternator or dynamo which is placed in a pivoting mounting at deck level. This allows for the rapid deployment of either a wind turbine or a water impeller, whilst placing most of the system's mass in a position where its adverse effects on the yacht's stability are minimised.

Preferably the machine should be constructed from lightweight, high strength, corrosion resistant materials, in order to maximise its utility.

A preferred embodiment of the invention will now be described with reference to the accompanying drawing in which: Figure 1 shows a side elevation of the generator in wind mode.

Figure 2 shows a front elevation of the generator in wind mode.

Figure 3 shows a side elevation of the generator in vertical water mode, with vertical water transmission 15 deployed.

Figure 4 shows a side elevation of the generator in drag water mode, with drag water transmission 18, bracket 17 and diving plane 19 deployed.

Figure 5 shows a plan view of the generator in drag water mode, with drag water impeller bracket 17 and diving plane 19 deployed.

As shown in Figure 1, the combined wind and water generator comprises a horizontal axis wind turbine 10, which is orientated downwind of the machine's yaw axis. The rotation of the turbine is vectored through a transmission 1, and directed through a telescopic drive shaft 2 to the alternator or dynamo 3 at the machine's base. The centre of the turbine, opposite to the transmission, is provided with a mounting bar 4. The mounting bar can be demountably fitted into a mounting socket 25 in the supporting element called a yaw arm 5, and locked into position with a pin or similar device 6. The yaw arm supports the turbine and transmission.

The yaw arm 5 is thin in section, as shown in Figure 2, to minimise wind and water drag, but has considerable lateral area to assist yawing the turbine 10. At the lower end of the yaw arm it is connected, via bushes 7, to the machine's main tower 23, which is tubular in section. The yaw arm is free to rotate around the machine's main tower. The yaw arm is provided with a catch 8 which retains the yaw arm in its raised position at the top of the tower, or upon its release, allows the yaw arm to slide down the tower. This brings the turbine mounting bar 4 and socket 25 to a convenient height to facilitate changing the turbine 10 and the transmission element 1 for the impeller 14 and its transmission element 18, and vice versa.

Upwind of the tower 23, the yaw arm 5 is provided with a handle 9 to facilitate turning the whole arm and turbine assembly out of the wind. An upper mounting point 11 is provided along the length of the tower in order to attach the upper mounting bracket assembly 24, which is secured to the mounting point 11 by a removable pin or similar device 20. The upper mounting point also controls the range of vertical travel of the yaw arm.

Below the upper tower mounting point 11, the tower 23 is connected to the electrical machine 3. The electrical machine could be an alternator, a dynamo, or even a device capable of direct work such as a pump or friction mill. The tower alternator joint is provided with drainage channels to allow water to escape from inside the tower. The alternator is provided with mounting points 12 for brackets which form the lower mounting of the machine. These mounting points are arranged in order to allow the alternator and tower to be pivoted from the vertical position through the horizontal along the axis of the vessel. These mounting points 12 are connected to the hull of the yacht or other mounting structure by bracketry 22. The bracketry is capable of freedom of movement in the horizontal plane due to the inclination of a pivot 13.

When the machine is to be operated in the water mode, the air turbine 10 is stopped by turning it out of the wind using the handle 9. The catch 8 is released, and the yaw arm 5 slid down the tower 23. The telescopic drive shaft 2 is disconnected from the transmission 1, the pin 6 is removed, and the air turbine and transmission is demounted.

The present invention allows for the wind turbine 10 to furl horizontally in strong winds in order to reduce the intercept area presented by the turbine to airflow. This reduces the wind loading on the turbine and its mountings whilst maintaining useful power output.

The furling is accomplished due to the machine's yaw axis being the same as the driveshaft axis. Up to the rated output of the electrical machine the wind loading on the turbine 10 and yaw arm 5 combine to oppose the back E. M. F. of the alternator 3 and orientate the turbine relatively normal to the airflow. As the rated output of the alternator is reached the back E. M. F. rises. The torque required to turn the alternator faster now exceeds the balancing force provided by the turbine and yaw arm wind loading. In consequence excess energy in the turbine causes both it and the yaw arm to turn out of the wind until a new state of equilibrium is reached. This mechanism is reliant on the alternator 3 being connected to a load. If it were disconnected the turbine 10 would be free to speed up and the furling effect would cease.

The invention also provides for rotor overspeed protection through the design of the fixed pitch air turbine blades 10 which allow for progressive aerodynamic stall as the velocity of the airstream increases, disproportionately to the increase in the angular velocity of the blades.

The invention provides for two forms of water mode. Which type is used depends on the architecture of the vessel to which the device is fitted. The vertical water mode shown in Figure 3 is analogous to the wind mode. The water turbine 14 is provided with a transmission element 15 which vectors the drive through the telescopic drive shaft 2. A mounting bar 4 is provided at the opposite end of the transmission 15. This locates in the mounting socket 25 at the top of the yaw arm 5 and is locked with a pin 6. The yaw arm is connected to the transom bracket 26 with a flexible coupling 16 such as a lanyard, the length of which determines the water depth at which the turbine 14 will operate.

To operate in vertical water mode once the water impeller has been fitted, the pin 20 securing the upper mounting point 11 to the upper mounting bracket 24 is removed, and the entire unit pivoted backwards through 1800. The upper tower mounting point is attached to the transom bracket 26 with the pin 20. As the vessel moves through the water, the yaw arm 5 now orientates the impeller 14 to the direction of water flow and the impeller rotates. The resulting torque is transmitted, via the transmission element 15 and telescopic drive shaft 2, to the alternator 3 at deck level.

This mode of deployment is not possible on yachts with retrousse (sloping) sterns. The invention therefore provides for a second form of water mode, the drag configuration, as shown in Figure 4. The water impeller 14 is mounted on a bracket 17, in order to provide a clearance from the yaw arm 5. One end of the bracket is inserted into the rear of the mounting socket 25 at the top of the yaw arm and secured with a pin 6 or similar device.

The impeller 14 is provided with a transmission element 18, which vectors the drive through the telescopic driveshaft 2.

At the other end of the bracket 17, a broadly horizontal plate 19 is provided. This acts as a diving plane, set at such an angle to ensure that a hydrodynamic force is generated when the assembly is drawn through the water. The purpose of the diving plane is to keep the impeller 14 submerged as it is drawn through the water. With the impeller normal to the water flow, a small downward force is produced by the plane. If the impeller rises through the water towards the surface, this force becomes much greater as the angle of attack of the diving plane 19 increases. The pivot 13, provided in the bracketry 22, allows the alternator, tower and yaw arm assembly to orientate the impeller 14 to the direction of the water flow. This enables the submersed impeller assembly to track accurately in the yacht's wake, and ensures that the yacht's steering is not impeded.

To deploy this form of the water mode, the air turbine 10 is first stopped and removed as described earlier. The water impeller bracket 17 is inserted into the rear of the mounting socket 25 at the top of the yaw arm 5 and secured with a pin 6 or similar device. The telescopic drive shaft 2 is connected to the transmission element 18 and the yaw arm returned to its position at the top of the tower 23 where it is locked in its raised position by the catch 8. A means is provided by which the yaw arm's freedom to rotate about the tower can be restricted or prevented when deployed in this mode. This assists the tracking and stability of the yaw arm in rough water conditions and is accomplished either by positioning catch 8 in a restraining groove in the upper tower guide bush 21, or by use of a secondary locking device, such as a spring plunger.

The upper mounting pin 20 is released, and the whole unit allowed to pivot backwards, and is thereby lowered into the water. As the vessel gets underway, hydrodynamic forces are balanced between thrust on the impeller 14 and downward lift from the diving plane 19 which combine to maintain the impeller position beneath the water surface. Torque from the impeller is transmitted through the transmission element 18 via the telescopic drive shaft 2 to the alternator 3 which remains at deck level.

In all three modes, the telescopic drive shaft 2 is provided with a means at its upper end to connect it to the transmission elements 1,15, 18. This connection both transmits torque and allows for a degree of angular misalignment. The drive shaft passes through an upper tower guide bush 21, and then continues centrally through the tower 23, and is connected to the drive shaft of the alternator 3 at the base of the tower. The upper tower guide bush 21 is larger in diameter than the tower and the yaw arm bushes and thus prevents the yaw arm 5 from passing beyond it.

The yaw arm 5 is provided with holes 27 through which lanyards can be attached in order to deploy and recover the water modes. The diving plane 19 is provided with a hole through which a lanyard can be rigged between it and the handle 9, in order to deflect floating debris from the impeller 14 when in use.

To change the machine from either water mode back to wind mode, the device is first raised through the horizontal to the vertical by use of a lanyard attached to the yaw arm 5.

It is secured in the vertical position using the upper mounting pin 20, as shown in Figure 1. The yaw arm catch 8 is released, and the yaw arm 5 slid down the tower 23. The telescopic drive shaft 2 is released from the transmission element 15 or 18, and the impeller mounting bracket 17 released from the yaw arm mounting socket 25 and removed. The air turbine mounting bar 4 is located in the yaw arm mounting socket, and secured with a locking pin 6 or similar device. The telescopic drive shaft 2 is attached to the transmission element 1. The yaw arm 5 is raised to the top of the tower 23, where it is retained with the locking catch 8. The yaw arm handle 9 is then released, allowing the machine to weathercock and start rotating.

Claims

CLAIMS 1. A combined wind and water generator that provides interchangeable wind and water turbine assemblies incorporating vectored transmission devices at their axes, which are selectively connected to a drive shaft that transmits torque to an electrical or other energy conversion device which is mounted to a sailing vessel using pivoted bracketry.
2. A combined wind and water generator as claimed in Claim 1 wherein an upwind horizontal axis wind turbine and vectored transmission assembly is provided, which is positioned downwind of the machine's yaw axis.
3. A combined wind and water generator as claimed in Claim 1 and 2 wherein a horizontal axis water impeller or turbine and vectored transmission assembly is provided which is capable of deployment in two configurations.
4. A combined wind and water generator as claimed in any preceding claim wherein the wind and water turbine vectored transmission assemblies are provided with a means to releasably mount the turbine assemblies to the yaw arm.
5. A combined wind and water generator as claimed in Claim 4 and any preceding claim wherein a yaw arm is provided with a means by which the wind and water turbine assemblies can be selectively releasably secured.
6. A combined wind and water generator as claimed in Claim 4,5 and any preceding claim wherein a yaw arm is provided which can rotate about, and slide axially along, the tubular tower.
7. A combined wind and water generator as claimed in Claim 4,5, 6 and any preceding claim wherein a yaw arm is provided with a means to selectively allow or prevent rotational and axial movement of the yaw arm in relation to the tubular tower.
8. A combined wind and water generator as claimed in Claim 4,5, 6,7 and any preceding claim wherein the yaw arm is provided with a means of affording purchase to the hand such that the yaw arm can be readily rotated about and slid along the tubular tower.
9. A combined wind and water generator as claimed in Claim 4,5, 6,7, 8 and any preceding claim wherein the yaw arm provided is thin in section but has considerable lateral area.
10. A combined wind and water generator as claimed in any preceding claim wherein a tubular tower is provided which at one end is rigidly attached to the electrical machine or other energy conversion device such that the axis of said elements lie concentrically along the axis of the tower tube.
11. A combined wind and water generator as claimed in any preceding claims wherein a rigid telescopic or flexible drive shaft is provided which transmits torque from the wind and water vectored transmission assemblies to the electrical machine or other energy conversion device.
12. A combined wind and water generator as claimed in Claim 10,11 and any preceding claim wherein the drive shaft passes concentrically through the tower tube.
13. A combined wind and water generator as claimed in any preceding claim wherein the orientation of the yaw axis being the same as the axis of the electrical or other energy conversion device allows for the furling of the air turbine in high wind speeds.
14. A combined wind and water generator as claimed in any preceding claims wherein primary mounting bracketry is provided with a means to selectively allow for, or prevent, pivoting movements of the wind and water in both horizontal and vertical planes.
15. A combined wind and water generator as claimed in Claim 14 and any preceding claim wherein secondary mounting bracketry is provided with a means to releasably lock said bracketry to the tower tube.
16. A combined wind and water generator as claimed in any preceding claim wherein one of the possible water configurations provides for a diving plane or other means by which hydrodynamic forces are utilised to prevent the water impeller from surfacing.
17. A combined wind and water generator as claimed in Claim 16 and any preceding claim wherein a means is provided to attach a line or similar device between the diving plane and the yaw arm in order to deflect debris away from the impeller.
18. A combined wind and water generator as claimed in Claim 16,17 and any preceding claim wherein a means is provided to attach a line, lanyard or similar device to allow for the deployment and recovery of the machine in either water mode.
19. A combined wind and water generator as claimed in any preceding claim wherein a means such as a bracket is provided for releasably securing the tower tube to allow for vertically orientated water mode, together with a lanyard, line or similar device as a means of controlling the position of the yaw arm, and therefore the operating depth of the impeller.
20. A combined wind and water generator substantially as described herein with reference to figures 1 to 5 of the accompanying drawings.