GB2097477A

GB2097477A - Revolving windmill generator apparatus

Info

Publication number: GB2097477A
Application number: GB8112798A
Authority: GB
Original assignee: Meisei University
Current assignee: Meisei University
Priority date: 1981-04-24
Filing date: 1981-04-24
Publication date: 1982-11-03
Also published as: GB2097477B

Abstract

The apparatus comprises a duct structure 1 and a revolving body 6, a windmill 13 and a generator 12. The duct structure 1 has an annular first floor 2 and an annular first roof 3 arranged substantially horizontally, vertical stationary guiding partitions 4 provided radially between the first floor and roof, and a central cylindrical space 5. The revolving body 6 has a circular second floor 8 and a circular second roof 9, and a pair of working fluid guide pillar members (10, Fig. 2 not shown) arranged between the second floor and roof. The revolving body is located within the cylindrical space 5 and is adapted for rotation about an axis coaxial with that of the central axis of the cylindrical space. The windmill 13 is connected to a generator 12 and supported for rotation about a horizontal axis within a hollow space, defined by the floor 8, roof 9 and the pair of guide pillar members (10) of the revolving body. Wind directional means 22 is provided for turning the revolving body 6 to point the windmill 13 in the windward direction. A number of such windmill units may be stacked one on top of the other to increase the electrical output obtained from a single installation (e.g. Fig. 8, not shown). <IMAGE>

Description

SPECIFICATION Windmill generator apparatus The present invention relates to a windmill generator apparatus.

Various types of windmill generator apparatus are known but the great majority of them have the windmill mounted at the top of a large steel tower or rigid structure. With a windmill apparatus of this type, considerable difficulties are encountered in devising countermeasures for protection against windstorms such as moderate gales and gusts and against turbulence, as well as in performing maintenance and inspection.

It is an object of the present invention to eliminate partially or wholly the technical difficulties encountered in the conventional windmill generator apparatus referred to above.

According to the present invention there is provided a windmill generators apparatus comprising: (a) a duct structure including: (i) a first annular floor and a first annular roof, of prescribed inner and outer diameters, substantially horizontally arranged and spaced apart from each other by a prescribed distance; (ii) a plurality of vertical stationary/guiding partitions radially provided between said first floor and said first roof; and (iii) a first space in the shape of a hollow cylinder which is formed within the central portion of said duct structure; (b) a revolving body including: (i) a circular second floor and a circular second roof of outer diameters smaller than the outer diameter of the first space, the inner sides of said second floor and of said second roof defining a smooth of said second roof defining a smooth continuous surface with the inner sides of said first floor and said first roof, (ii) two duct-forming guide pillar members arranged between said second floor and said second roof symmetrically at the outer circumferential portions thereof taking as a plane of symmetry, planes that contain the diameters of said second floor and said second roof, each of said guide pillar members comprising a ductblocking arcuate outer wall along the outer circumference of said second floor and said second roof, and a duct-forming curved inner wall connecting both side edges of said arcuate outer wall; and (iii) means for permitting said revolving body to rotate within said first space on an axis coaxial therewith; (c) a windmill supported for rotation about a horizontal axis within a second hollow space, defined by said second floor, said second roof and by said two guide pillar members of said revolving body; (d) an electrical generator driven by said windmill; and (e) wind directional means for turning said revolving body so as to point said windmill in the windward direction.

The present invention will now be described in greater detail by way of example with reference to the accompanying drawings, wherein: Figure 1 is a vertical sectional view illustrating a first preferred embodiment of a windmill generator apparatus, the section being taken along the line B-B of Figure 2; Figure 2 is a sectional view taken along the line A-A of Figure 1; Figure 3 is a vertical sectional view illustrating a second preferred embodiment of a windmill generator apparatus, the section being taken along the line D-D of Figure 4; Figure 4 is a sectional view taken along the line C-C of Figure 3;; Figure 5 is a vertical sectional view illustrating a third preferred embodiment of a windmill generator apparatus, the section being taken along the line F-F of Figure 6; Figure 6 is a sectional view taken along the line E-E of Figure 5; Figure 7 is a vertical sectional view illustrating a fourth preferred embodiment of a windmill generator apparatus; Figure 8 is a vertical sectional view illustrating a fifth preferred embodiment of a windmill generator apparatus employing several units arranged in cascade; Figure 9 is a vertical sectional view illustrating a sixth preferred embodiment of a windmill generator apparatus units employing several units arranged in cascade; Figure 10 is a vertical sectional view illustrating a modification of the arrangement shown in Figure 8; and Figure 11 is a vertical sectional view illustrating a modification of the arrangement shown in Figure 91.

Before turning to the description of the preferred embodiments, the principle of operation of a windmill generator apparatus employed will be described in detail.

When a cylindrical object is placed in a fluid which is flowing in a single direction, a positive pressure is generally developed over a range of approximately 300 on both the right and left sides of the centre line of the cylinder at the front end thereof, namely the side that is facing the fluid flow, and a negative pressure is developed at the side and back of the cylinder, the negative pressure at the side being greater than that at the back so that a back flow tends to develop along the outer periphery of the cylinder. In many cases a Karman vortex will be produced behind the back surface of the cylinder.Accordingly, if a windmill mechanism of the type having a horizontal rotational axis were to be located so as to turn freely in accordance with the wind direction within a hollow cylindrical shape formed internally of an annular duct structure having a multiplicity of vertical stationary guide partitions arranged radially between an annular floor and roof, and if a power conversion mechanism were coupled to the windmill for converting the rotational energy generated by the windmill into another form of power, wind of a positive pressure that has entered the duct structure from the windward direction would reach the windmill mechanism after being converged by the stationary guiding partitions at the front or windward side to rotate the windmill located at such position. The wind current of a negative pressure would flow rearward from the sides and back of the duct structure.For laminar flow along an object having a cylindrically shaped outer surface, the boundary between the negative and positive pressure regions is located at an angle of about 300 on either side of the windward face, and the pressure gradient is steep in the vicinity of the boundary.

However, when the arrangement is such that fluid will pass through a cylindrical space internally accommodating the windmill mechanism surrounded by the circumferential array of the radially located stationary guiding partitions, the angle at which the boundarv is located is generally enlarged beyond 300, althougn the angle is not constant owing to effects such as fluid resistance and viscosity, flow speed, and the weight of the windmill.

Experiments have shown, however, that the angle can be enlarged to about 450. Furthermore, natural winds include three-dimensional vortex flows superimposed on the laminar flow of the principal wind direction in a complex manner, so that wind direction in certain locations may constantly fluctuate irregularly centering about the principal wind direction. The windmill mechanism will follow these changes in wind direction only after some delay. It is therefore difficult to determine the boundary between the positive and negative pressures. In embodiments of the present invention, a pair of guide pillar members rotated together with the windmill mechanism are provided to avoid such disturbance of a pressure gradient that fluctuates with time and place.

Each guide pillar member comprises an arcuate blocking outer wall, which is adjacent the inner circumferential surface of the duct structure at the outer circumferential portion of the freely revolving windmill mechanism, for blocking the inflow and outflow of wind from the radially arranged stationary guiding partitions over an angle of from about 200 to 1400 on either side of the horizontally directed axis of rotation of the windmill, and a duct-forming curved inner wall which is located on the inside of the windmill mechanism and which interconnects both side edges of the blocking outer wall. The force of the wind can be extracted effectively by providing rectifying vanes and/or windmill guiding vanes between the two guide pillar members.The outer diameter of the duct structure in the apparatus depends upon the environmental conditions at the site where installed, and is preferably not less than 1.5 times the inner diameters The rectifying vanes and/or the guiding vanes are not necessarily required, but they may be installed advantageously in each duct located in the annular duct structure.

Various embodiments of the windmill generator apparatus will now be illustrated in greater detail with reference to the accompanying drawings.

Referring to the first embodiment illustrated in Figures 1 and 2, the windmill generator apparatus includes an annular duct structure 1 having a plurality of vertical stationary guiding partitions 4 arranged radially at a prescribed pitch such as 10 between a first floor 2 and first roof 3 which are annular in shape and horizontally arranged and spaced apart from each other by a prescribed distance. Located within the inner circumferential portion of the annular duct structure is a first hollow cylindrical space 5 that accommodates a revolving body 6 equipped with a windmill generator that will be described later.

In an alternative form, the roof 3 may be formed to have an outer diameter larger than that of the floor 2 so that it will project in the manner of a canopy beyond the outer edges of the stationary partitions 4 to prevent rain or snow from penetrating the interior of the annular duct structure 1. In addition, to prevent heavy rain or snow from penetrating the ducts 7 formed between adjacent ones of the stationary guiding partitions 4, doors such as shutters may be provided in the entrance to each duct to close off all or a portion of the duct, or openable and ciosable doors mounted on hinges may be provided midway along the stationary guiding partitions 4. Such an arrangement also allows the ducts 7 to be shut off when the revolving body 6 is to be subjected to maintenance and inspection.

The revolving body 6 includes a second floor 8 and a second roof 9 which are circular in shape and of a diameter that is slightly less than the inner diameter of the first floor 2 and roof 3 of the annular duct structure 1, i.e., slightly less than the outer diameter of the first hollow cylindrical space 5, the second floor 8 and roof 9 being arranged so as to be spaced apart by the same distance as that separating the first floor 2 and roof 3. Also included in the revolving body 6 and located between the second floor 8 and roof 9 are a pair of duct-forming guide pillar members 10 and guiding wall members 11 by which the structure of the revolving body 6 is connected and supported. Each of the duct-forming guide pillar members 10 comprises an arcuate outer wall 10,, along the outer circumference of the second floor 8 and roof 9, for blocking the ducts 7, and a duct forming curved inner wall 102 connecting both side edges of the arcuate outer wall 101. The two duct-forming guide pillar members are arranged symmetrically at the outer circumferential portion of the second floor 8 and roof 9 taking as a plane of a symmetry, the plane that contains the diameters of the second floor 8 and roof 9.The floor 8 and the roof 9 have respective centrally located rotary shafts 1 6 and 17, that are rotatably supported by respective bearings 20 and 21 mounted in corresponding supporting discs or respective supporting arms 18 and 19 extending from the inner circumferential portions of the first floor 2 and roof 3, of the annular duct structure 1, towards the centre thereof. Thus the entire revolving body 6 is capable of turning freely within the hollow cylindrical space 5 in the inner circumferential portion of the annular duct structure 1. It will be noted that a second hollow space 23 is formed by the surrounding second floor 8 and roof 9 and the two guide pillar members 10 of the revolving body 6.Supported within the second hollow space 23 by a rectifying vane 14 and guiding vanes 1 5 is a windmill generator 12 having a windmill 13 that rotates about an axis which coincides with the horizontal axis of the second hollow space 23.

The rotary shaft 1 7 provided on the second roof 9 of the revolving body 6 has an upward extension to which is attached a wind vane 22 arranged in the same direction as the axis of rotation of the windmill 1 3, whereby the revolving body 6 will be caused to turn so as to point the windmill 1 3 toward the windward direction at all times.

The guide pillar members 10 of the revolving body 6 are provided to cover an angle ranging from about 200 to 1400 on both sides of the horizontal axis of rotation of the windmill 13 on a horizontal plane containing said axis of rotation, thereby to block the ducts 7 which are formed by the stationary guiding partitions 4 of the annular duct structure 1 within the above range of angles. The effect of blocking off the ducts 7 is similar to that which would be achieved by closing the same ducts at the outer ends thereof. This promotes the negative pressure on the leeward side of the annular structure 1 to reduce the occurrence of vortex currents.

In order to heighten the efficiency of the windmill 13, the windmill 13 and guiding vanes 1 5 may be provided with variable pitch mechanisms in accordance with the ordinary fluidic machine concepts.

In the windmill generator apparatus described above, portions such as the annular duct structure and revolving body can be constructed of material such as steel reinforced concrete or steel members that are able to tolerate turbulence, strong gusts and gales, with members such as the windmill 13 being accommodated within the apparatus. As a result, members such as the windmill will not be subjected to the violent effects of a Coriolis force that accompanies turbulence or sudden changes in wind direction, and power can be generated more efficiently by the force of the wind.

Referring now to the second embodiment shown in Figures 3 and 4, the construction differs from that shown in Figures 1 and 2 in that the distance between the first floor 2 and roof 3 of the annular duct structure 1 is gradually enlarged from the inner circumference of the structure to the outer circumference thereof. The arrangement is identical with that of Figures 1 and 2 in all other aspects, but utilizes the wind power much more efficiently.

Referring now to the third embodiment shown in Figures 5 and 6, the windmill apparatus includes an annular duct structure 1 having a plurality of vertical stationary guiding partitions 4 arranged radially between a first floor 2 and a first roof 3 which are annular in shape and horizontally arranged. A hollow cylindrical space 5 is formed within the annular duct structure 1. A revolving body 6 is connected and supported by two ductforming guide pillar members 10 and a guiding wall member 1 each guide pillar member 10 comprising a duct-blocking arcuate outer wall 101 and a duct-forming curved inner wall 102, the two guide pillar members 10 and the guiding wall members 11 being located between a circular second floor 8 and circular second roof 9.The revolving body 6 is provided with four equispaced wheels 25 that are attached to the lower side of the floor 8 and arranged to travel around a circular rail 26 located on a circular base 24. The revolving body 6 has a windmill generator 12 mounted inside, and a wind directional vane 22 attached to the upper surface of its roof 9.

Referring now to the fourth embodiment shown in Figure 7, the construction differs from that shown in Figures 5 and 6 in that the distance between the annular first floor 2 and roof 3 of the duct possessing structure 1 is gradually enlarged from the inner circumference of the structure to the outer circumference thereof. The arrangement is identical with that of Figures 5 and 6 in all other aspects. It should be noted that a section taken along the line G-G would present a view identical to that of Figure 4.

Figures 8 and 10 illustrate a first cascade arrangement in which a number of units of the windmill generator apparatus of the type shown in Figures 1 and 3, respectively, are stacked in order to increase the electrical output obtained from the wind power at a single installation. This will be described with reference to Figure 8.

Annular duct structures 11,12,13,14 are stacked coaxially one on top of the other in the order mentioned. The lowermost revolving body 6, has a second floor 8 equipped with a bearing portion, but the roof 9 is merely a circular plate from which the supporting disc 19, bearing 21, rotary shaft 17 and wind directional vane 22 have been removed. The uppermost revolving body 64 has a second roof 9 equipped with a supporting disc 19, rotary shaft 17, bearing 21 and wind directional vane 22, but the second floor 8 is merely a circular plate from which the supporting disc 18, bearing 20 and rotary shaft 1 6 have been removed. The second floor 8 and second roof 9 of each of the intermediate revolving bodies 62, 63 are merely circular plates. The revolving bodies 61,62,63,64 are stacked one on top of the other in the order mentioned and constitute a single structure, so that the revolving bodies revolve in synchonism within a hollow cylindrical space defined within the stacked annular duct structures 11,12,13,14.

The modified arrangement shown in Figure 10 may be obtained by stacking the apparatus of Figure 3 in the manner described above.

should be obvious that almost the same method can be employed to stack the apparatus shown in Figure 5.

Figures 9 and 11 illustrate a second cascade arrangement of the windmill generator apparatus.

In the arrangements shown, the windmill generator does not have a direct connection between the windmill and the generator section, as in the previous embodiments. Instead, the arrangement is such that the rotational motion of the windmill 1 3 is transmitted to a generator unit 29 through a bevel gear mechanism 27 and a common vertical rotary shaft 28.

It should be noted that the role of pointing the horizontal axis of rotation of the windmill in the windward direction need not necessarily be performed by the wind directional vane described above. The same role can be performed by a separately provided wind direction sensor adapted to generate signals for the purpose of directional control.

The following advantaces can be achieved by the embodiments of the windmill generating apparatus described above.

(a) Since the annular duct structure is constructed of steel reinforced concrete or of steel plates, the interior of the revolving body, which includes the windmill, is fully protected from the effects of gales, wind gusts and turbulence. The annular duct structure supplies the windmill with effective positive and negative pressures and both rectifies and converges the wind to enhance effectiveness.

(b) The revolving body rotates gently while adapting to wind direction to convert the wind power into another form of power in an extremely efficient manner.

(c) The rotary blades of the windmill are subjected to centrifugal forces as they rotate, and they move in a complex manner on the basis of certain hydromechanical essentials. Hence, since there is a limit upon the strength of materials, there is also a limit upon the extent to which the blades can be enlarged. The above described windmill generating apparatus offers a solution by the arrangements shown in any one of Figures 8 to 11, where a number of the windmill generator units are stacked and the outputs of the individual windmills are combined to allow a reduction in the amount of space required for installation and to permit the utilization of winds high above the earth's surface. The end result is an improvement in overall economy.

(d) The annular duct structure, in addition to having the vertical stationary guiding partitions, may be provided with horizontal vanes installed in the ducts between adjacent ones of the guiding partitions, with mesh screens mounted in the ducts for keeping out foreign matter, or with reinforcing members inserted within the ducts.

(e) If the annular duct structure and the like are divided into a number of units and the units are conveyed to the site and assembled to erect the apparatus, conveyance to the site and installation at sites of limited area can be facilitated. The possibility of mass production may also be expected.

(f) If the apparatus is installed at a site where there is a prevailing wind direction or where an obstacle blocking the wind is located nearby, the annular duct structure can be so modified as to conform to the prevailing wind direction in an effective manner. It is also possible to gradually flare the floor and roof of the annular duct structure in the direction of their perimeters in order to smooth the flow of wind into the ducts.

(g) Each of the ducts formed between the adjacent stationary guiding partitions of the annular duct structure may be provided with a door for closing off all or a portion of the duct.

This would prevent heavy rain, hail, snow and strong winds from penetrating the interior, and would assure the safety of personnel who have entered the apparatus for inspection or maintenance.

(h) In general, windmills have a tendency to produce noise. This is difficult to prevent, and the noise is difficult to shield. One advantage of the present apparatus, however, is that the noise can be greatly suppressed by suitably selecting the surface materials and shape of such members as the floors, roofs, stationary guiding partitions, rectifying vanes and guiding vanes, Although in the first embodiment as shown in Figure 2, there are 36 vertical stationary guiding partitions 4 arranged in equi-spaced relation at a pitch of 100, it has been found that the prescribed pitch can be varied within the range 50--300 to suit particular requirements and particular localities. The second embodiment shown in Figure 4 has a pitch of 150.

Furthermore, the angular extent of the outer wall 10, may be varied within the range 200-- 1400. In the first embodiment the angular extent is 1000 and in the second embodiment it is 750.

Claims

1. A windmill generator apparatus comprising: (a) a duct structure including: (i) a first annular floor and a first annular roof, of prescribed inner and outer diameters, substantially horizontally arranged and spaced apart from each other by a prescribed distance; (ii) a plurality of vertical stationary/guiding partitions radially provided between said first floor and said first roof; and (iii) a first space in the shape of a hollow cylinder which is formed within the central portion of said duct structure; (b) a revolving body including: (i) a circular second floor and a circular second roof of outer diameters smaller than the outer diameter of the first space, the inner sides of said second floor and of said second roof defining a smooth continuous surface with the inner sides of said first floor and said first roof;; (ii) two duct-forming guide pillar members arranged between said second floor and said second roof symmetrically at the outer circumferential portions thereof taking as a plane of symmetry, planes that contain the diameters of said second floor and said second roof, each of said guide pillar members comprising a duct blocking arcuate outer wall along the outer circumference of said second floor and said second roof, and a duct-forming curved inner wall connecting both side edges of said arcuate outer wall; and (iii) means for permitting said revolving body to rotate within said first space on an axis coaxial therewith; (c) a windmill supported for rotation about a horizontal axis within a second hollow space, defined by said second floor, said second roof and said two guide pillar members of said revolving body; (d) an electrical generator driven by said windmill; and (e) wind directional means for turning said revolving body so as to point said windmill in the windward direction.

2. A windmill generator apparatus according to Claim 1, wherein the first floor and first roof of said duct structure are arranged in parallel planes with each other.

3. A windmill generator apparatus according to Claim 1, wherein the distance between the first floor and first roof of said duct structure is gradually increased from the inner to the outer circumference thereof.

4. A windmill generator apparatus according to Claim 1 , wherein which the angular spacing between adjacent ones of the radially arrayed vertical stationary guiding partitions of said duct structure ranges from 5 to 300.

5. A windmill generator apparatus according to Claim 1 , wherein which the angular spacing between both side edges of the duct-blocking arcuate outer wall constituting said duct-forming guide pillar member of said revolving body ranges from about 20 to 1400.

6. A windmill generator apparatus including a plurality of windmill units constructed in accordance with any one of the preceding claims, wherein said windmill units are stacked coaxially one on top of the other and arranged so as to align the axis of rotation of each windmill unit in the same direction.

7. A windmill generating apparatus according to Claim 6, wherein the duct structures of each windmill unit are integrated to form a single structure, and wherein the revolving bodies of each windmill unit are integrated to form a single unit.

8. A windmill generating apparatus according to Claim 6 or 7, wherein there are as many electrical generators as there are windmill units, each generator being driven by a respective windmill.

9. A windmill generating apparatus according to Claim 6 or 7, wherein there is a single electrical generator, which is driven by all the windmills through a central vertical shaft extending through the stack of windmill units and coupled to each windmill in the stack by means of bevel gearing.

1 0. A windmill generating apparatus according to any one of the preceding claims, wherein said means for permitting said revovling body to rotate comprises a circular track mounted on a floor member within the first annular floor of the bottom windmill unit of the stack, and a plurality of equi-spaced wheels for engaging the circular track located on the bottom of the second of the rotating body or the second floor of the bottom windmill unit of the stack.

11. A windmill generating apparatus according to any one of the preceding claims 1 to 9, wherein said means for permitting said revolving body to rotate, comprises shafts connected to the second floor and second roof journalled in bearings provided in central extensions of the first floor and first roof in the case of a single unit, or shafts connected to the second floor of the bottom windmill unit and the second roof of the top windmill unit, said shafts being journalled in bearings provided in central extensions of the first floor of the bottom windmill unit and the first roof of the top windmill unit in the case where there is a stack of windmill units.

1 2. A windmill generating apparatus constructed and arranged to operate substantially as herein described with reference to and as illustrated in Figures 1 and 2, or Figures 3 and 4, or Figures 5 and 6 or Figure 7 of the accompanying drawings.

13. A windmill generating apparatus constructed of a plurality of windmill units and arranged to operate substantially as herein described with reference to and as illustrated in Figure 8, or Figure 9, or Figure 10, or Figure 11 of the accompanying drawings.