GB2049831A

GB2049831A - Wind Turbine Plant

Info

Publication number: GB2049831A
Application number: GB8023326A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-05-29
Filing date: 1980-05-16
Publication date: 1980-12-31

Abstract

The plant includes a platform 3 which is maintained aloft by the vertical force component generated by rotation of the inclined axis wind turbine rotor 5, the platform being tethered to the ground by at least three cables 2, another form of rotor is also described. <IMAGE>

Description

SPECIFICATION Self-supporting Wind Power Station Background of the Invention The invention relates to the wind power station, which is kept high by the own power.

Since long time, peaple use the power of the wind to drive mills, pumps, ships and small electric power stations. For great powers, there exist the following impediments: Neat the ground, the wind velocity is to low and the wind wheels must have a great diameter. To reach the useful velocity, the wind wheels must work 1800--2400 foot high and it is not possible, to build such towers at a reasonable price. From the patent literature, there are few solutions of this problem well known, but a practic significance have only two of them: to use wind wheel mounted on the captive ballon, or, to use an autogiro-helicopter with a very small wing load, whereby the small part of the wind energy keeps the power station high, the greater part of energy givs as the usefull power.The construction with captive ballons has the following disadvantages: it is very difficult to anchor the great forces of the wind wheel on the ballon; the lifting gas must be replenished and, for the ice-formation, it is impossible to maintain the power station in winter.

At first sight, it is better to use an autogiro principle with a very low wing load and on a cable anchored. At calm, the rotor can work as a helicopter and keeps the power station high. By practical calculation and construction, we meet the following insuperable impediments: The normal helicopter or autogiro works with the speed 60-100 m.p.h., the power station must work with 1/4-1/5 of it. Of course, the RPM of the rotor are 1/4-1/5 too. Because the centrifugal force is proportional to the square of the angular velocity, we obtain ca 1/20 of said force only. It is weli known, to adjust a different ascending force on the left and right side of the rotor, the single blades must be mounted so, that they can oscillate in the vertical plane.To bring them back to the horizontal plane, is due to the said centrifugal force. To keep a reasonable oscillating angle, the said force must be 10 times higher as the ascending force. In this case, both the forces are equal and a stable operation is impossible. The second impediment is a compensation of the torque. A normal autogiro has no torque, but if we drow energy from or feed energy to the rotor, we obtain at low RPM a very high torque. To compensate this torque, one has 2 possibilities: either 2 opposite rotors, or an auxiliary rotor on the tail of the apparatus. In the first case, one needs 2 heavy gears and 2 rotors and it is impossible to reach a low wing load 0.4 Ib/sq ft. In the second case, by a normal helicopter rotor with high angular velocity, the required power for the auxiliary rotor is ca 10% of the main power only.In our case one needs 40-60%. The third impediment is a great difference between the rotor speed and generator speed. By a normal helicopter, the speed of the rotor is ca 300 RPM and the speed of the rotor ca 3000 RPM, one needs a gear with speed ratio 1:10. In our case, by the statios with high power and great rotor-diameter, the speed of the rotor is 3-36 RPM only, but the speed of the generator is 3000-3600 RPM again and we need a gear with speed ratio 1:100-1:1000. Such gears have the same weight as a generator and efficiency 8060% only. Again, it is impossible to reach a low wing load.

Summary of the Invention If we calculate a normal wind wheel with a horizontal axis, we obtain in addition to the torque a great axial force too. For example, for a wind wheel D-80 foot, and wind velocity 22 m.p.h., we obtain a power 120kW and an axial force 5300 Ib. With an oblique position of the wheel axis, s. Fig. 1, we can win part of this force as a lifting force.

If V is a horizontal wind velocity, then the component V1 V 1=V sin cr This component couses the axial force (Fig. 2) P p rrD2 F1=0.8 q - V21=0 q -- VZ sin2a q- 2 2 4 and the power P P N=0.4 q - V31 =0.4 q - V3 sin3a 2 2 The lifting force p FV=F, cos=0.8 q - V2 sin2o cos a 2 The function sin2a cosa has a maximum at it=550, in this case sin2a cos=0.38 and sin3c=0.54 In comparison with a normal wind wheel with a horizontal axis, we obtain 54% of the power and 38% of the axial force as a lift. This lift is sufficient to keep the power station high and, we obtain it without difficulties with an autogiro-rotor. Fig. 3 shows a three-point suspension, it can withstand a torque. If the base 1 has only a lift Fy without a torque, the anchor cables 2 stand erect. If a torque M is arising, the cables come aslant with the angle,3 and originate a tangential force Ft, which compensates the torque M.

Brief Description of the Drawings Fig. 1, 2, 3 were just described, they are for the fundamental idea explanation only.

Fig. 4 is a practical construction for medium and great powers.

Fig. 5 is a construction with an "aerodynamic transmission".

Fig. 6 is a construction with the Savoniusrotor.

Fig. 6a is a section view of the Savonius-rotor.

Fig. 7 is the ground station for anchoring of the cables.

Detailed Description of the Invention A practical construction shows Fig. 4. The wind wheel 5 has the axis 6 and this axis is embedded in the tube 4. Through the bearing 7, the said tube may be turned about the horizontal bolt 9. The bearing 7 is mounted on the auxiliary base 3 and this base can rotate around the vertical axis 10.

On the top end of the axis 6, the girder 1 5 with the horizontal vane 14 is freely mounted.

On the bottom end of said axis, there the gear 11 and the generator 12 is mounted. The complete apparatus is fixed on the main base 1 and is anchored to the ground with the cables 2 with insulators 13 according to Fig. 3. These cables transmit the el. power, too. Under starting or calm conditions, the generator 1 2 works as a motor, the wind wheel comes into position II and generates the required lift force. By a suitable wind, the wind wheel comes automatically into the right direction and by the vane 14 the wind wheel is tilted into the working-position II. For a very high powers, the wind wheel diameter is to great, the RPM to low and the required gear is to heavy and efficiency to low. In this case, it is better to use a construction according to Fig. 5.

On the ends of the blades of the wind wheel 5 the generators (and motors) 1 6 with the propeller 1 7 are mounted. Because, the circumferential speed is ca 5 times higher than the wind velocity, one wins with a relatively small propeller a high power by high RPM. The efficiency of this "aerodynamic transmission" is 50% only but one has not a heavy gear and torque.

Of course, there is in this case a difference between the lift on the right and left side of the wind wheel. In comparison with an autogiro rotor, this difference is low and is automatically compensated by an across incline of the apparatus.

Fig. 6 shows a construction with a Savoniusrotor, it is suitable for lower power. Instead of a normal wind wheel, the auxiliary base 3 carries the Savonius-rotor 18 with the horizontal axis 1 9.

This axis is coupled through the gear 11 with the generator (and motor) 12.

The vertical vane 20 keeps the rotor square to the wind direction.

Fig. 6a is the section view of the Savoniusrotor. Because, the lift force of this rotor is Fv=kVa) we can keep the apparatus high by a weak wind with faster rotation of the rotor. Fig. 7 shows one of the three ground stations with a winch for the anchor-cables. The platform 21 is held by insulators 22. On this platform the winch 23 with worm gear 24 is mounted, which gear is driven via the insulating shaft 25 by the el. motor 26. All 3 motors must work synchronously.

Claims

1) Self-supporting wind power station with inclined placed wind wheel, kept high at least by three radial directed cables and a vertical component of the axial force from said wind wheel in one point of space, comprising: main base, which is anchored by at least three said radial directed cables to the ground; wind wheel on the axis, the other end of said axis is coupled with the gear to a generator, it can work as a motor too and said axis is bedded in a tube, which can turn round a horizontal bearing; auxiliary base, it is free coupled with said main base and can rotate round a vertical axis, said horizontal bearing is eccentrically mounted on this base; horizontal base, it is free coupled on the top end of said axis, or other means, which keep said wind wheel by an optimal vertical angle.

2) Self-supporting wind power station according to claim 1, but without generator coupled with the main axis, comprising; two or more generators, which can work as motors too and which are mounted on the ends of blades from said wind wheel and driven by independent propellers.

3) Self-supporting wind power station according to claim 1, but the inclined placed wind wheel is substituted by the Savonius-rotor with a horizontal axis.