GB2431208A

GB2431208A - Electrical power generating turbine

Info

Publication number: GB2431208A
Application number: GB0520898A
Authority: GB
Inventors: William Forbes
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-10-14
Filing date: 2005-10-14
Publication date: 2007-04-18
Also published as: GB0520898D0

Abstract

An electrical power generator 10 is provided comprising a gas conduit 12 having a gas inlet 18 and a gas outlet 20 and a turbine (not shown) for generating electrical power, the turbine having rotor blades located within the conduit 12. The conduit 12 being adapted to generate a flow of a first gas therethrough upon application of a flow of a second gas across the gas inlet 18 or outlet 20. The rotor blades of the turbine are driven by air flowing through the conduit 12 from the gas inlet 18 to the gas outlet 20. Air flow through the conduit 12 may be created by generating a pressure differential between the top and bottom portions of the conduit 12 by air flowing across the gas outlet 20. Additionally,or alternatively, air flow through the conduit 12 may be created by generating a temperature gradient between the top and bottom portions of the conduit 12.

Description

1 Generator 3 The present invention relates to a generator for 4

generating electrical power.

6 Conventional generators which rely on wind power for 7 the generation of electricity, such as wind 8 turbines, have the disadvantage that the blades of 9 the rotor have to be positioned such that they are in alignment with the direction of the prevailing 11 wind. This requires the rotor to be rotatably 12 mounted so that it can rotate into the direction the 13 wind is coming from. Furthermore, if there is only 14 a slight wind, the blades of the rotor will not rotate and therefore not generate any electricity.

17 It is an object of the present invention to provide 18 an electrical power generator which obviates or 19 mitigates one or more of the disadvantages referred to above.

1 According to a first aspect of the present 2 invention, there is provide an electrical power 3 generator comprising: 4 a gas extraction conduit, said gas extraction conduit having a gas inlet and a gas outlet; and 6 a turbine for generating electrical power, said 7 turbine having rotor blades located with said 8 conduit.

Preferably, the conduit is substantially cylindrical 11 with a longitudinal axis.

13 Preferably, the gas inlet and gas outlet are at 14 opposite ends of the conduit.

16 Preferably, the gas outlet lies in a plane which is 17 substantially perpendicular to the longitudinal axis 18 of the conduit.

Preferably, the gas outlet is in the shape of a 21 funnel.

23 Preferably, the generator further comprises a cap 24 located adjacent the gas outlet.

26 Preferably, the cap is an aerofoil.

28 Preferably, at least a portion of the conduit is 29 tapered along its longitudinal axis.

31 Preferably, at least an upper portion of the conduit 32 is made from a black body material.

2 A black body is considered here to be a body in 3 which the absorptance and emissivity are 4 substantially equal to 1.

6 Preferably, the gas inlet is located at a position 7 which is remote from the end of the conduit.

9 Preferably, the gas inlet is in the shape of a funnel.

12 Preferably, the gas inlet is covered with a grating.

14 Preferably, the rotor blades are helical.

16 According to a second aspect of the present 17 invention there is provided a lighting apparatus 18 comprising: 19 illumination means; and an electrical power generator according to the 21 first aspect, wherein the illumination means is 22 powered by the electrical power generator.

24 According to a third aspect of the present invention, there is provided a method of generating 26 electrical power comprising the steps of: 27 locating the rotor blades of a turbine within a 28 gas extraction conduit having a gas inlet and a gas 29 outlet; and creating a gas flow through the conduit by 31 passing gas across the gas outlet or gas inlet.

1 Embodiments of the present invention will now be 2 described, by way of example only, with reference to 3 the accompanying drawings, in which:Fig. 1 is a side view of an electrical power 6 generator in accordance with the present invention; 8 Fig. 2 is a perspective view of an alternative cap 9 of the electrical power generator Fig. 1; 11 Fig. 3 is a perspective view of the fan of the 12 turbine of the electrical power generator of Fig. 1; 14 Fig. 4 a perspective view of the generator unit of the turbine the electrical power generator of Fig. 16 1; 18 Fig. 5 is an in-use side view of two alternative 19 installations of the electrical power generator of Fig. 1; 22 Fig. 6 is a side view of an alternative arrangement 23 of the electrical power generator of Fig. 1; and Fig. 7 is a side view of a lighting apparatus which 26 incorporates the electrical power generator of Fig. 27 1.

29 With reference to the accompanying drawings, an electrical power generator 10 comprises a gas 31 extraction conduit 12 and a turbine 14 for 32 generating electrical power.

I

2 As illustrated in Fig. 1, the gas extraction conduit 3 12 is cylindrical with a longitudinal axis 16. The 4 conduit 12 also has a gas inlet 18 and a gas outlet 20 located at opposite ends of the conduit 12.

7 Although not illustrated in the figures, the conduit 8 12 has a tapered portion along its longitudinal axis 9 16. The tapered portion acts like a venturi and causes an increase in the gas velocity therethrough.

12 The conduit 12 may be provided in sections 22, such 13 that its length may be varied. The sections 22 may 14 be connected together by push-fitting, or any other suitable type of connection. The sections 22 may 16 also include rubber seal, or the like, to ensure an 17 air-tight fit.

19 As illustrated in Fig. 1, the top portion of the conduit 12 is made from a black body material. A 21 black body is considered here to be a body in which 22 the absorptance and emissivity are substantially 23 equal to 1.

The gas inlet 18 is in the shape of a funnel, and 26 lies in a plane which is substantially parallel to 27 the longitudinal axis 16. It should be appreciated 28 that the gas inlet 18 could be in any suitable shape 29 and orientated in any suitable position to allow the influx of gas.

1 The gas inlet 18 also includes a grating 24, which 2 covers the inlet 18 to prevent unwanted objects 3 entering the conduit 12.

The gas outlet 20 is also in the shape of a funnel, 6 and lies in a plane which is substantially 7 perpendicular to the longitudinal axis 16.

9 The generator 10 further comprises a cap 26 (cowl, wire etc.) located adjacent the gas outlet 20. The 11 cap 26 acts to prevent rain, snow etc. from entering 12 the conduit 12.

14 As illustrated in Fig. 2, the cap 26 can be shaped as an aerofoil. In this case the cap 26 modifies 16 the gas flow passing over it to enhance the gas flow 17 through the conduit 12.

19 As illustrated in Figs. 3 and 4, the turbine 14 comprises rotor blades 28 and a generator unit 30.

21 The turbine 14 is positioned within the conduit 12.

22 The rotor blades 28 and the generator unit 30 are 23 aligned along the longitudinal axis 16 and are 24 connected together by a drive shaft 32.

26 The rotor blades 28 are arranged in a helical 27 arrangement about the axis 16. However, it should 28 be appreciated that any suitable arrangement of 29 rotor blades could be used.

31 The rotor blades 28 are manufactured from a 32 lightweight plastic, thus they are easily rotatable 1 in only slight winds. However, it should be 2 appreciated that any suitable material could be used 3 to manufacture the blades 28.

The rotor blades 28 are held in place by connectors 6 34 which are mounted to an internal surface of the 7 conduit 12. The connectors 34 may be resiliently 8 mounted to the conduit 12 to suppress vibrations and 9 noise. The conduit 12 may also be lagged to suppress noise.

12 A conical gas deflector 36 may also be positioned 13 below the rotor blades 28. The deflector 36 14 enhances the gas flow by deflecting the gas onto the blades 28.

17 In a domestic installation, the rotor blades 28 are 18 typically set within a conduit section approximately 19 lm in length. The blades 28 being approximately 900mm in length. This gives a combined blade 21 surface area of 0.3m2. In normal weather 22 conditions, this will generate average drive speeds 23 of 500 rpm, which is sufficient to generate 24 approximately 1kW of electricity. However, it should be appreciated that the length and size of 26 the rotor blades 28 can be varied to suit a 27 particular application.

29 As described above, the generator unit 30 is positioned above the rotor blades 28 and connected 31 thereto by the drive shaft 32. The drive shaft 32 32 turns central windings (not shown) which are set 1 within a magnetic shroud 38. The resultant 2 electrical energy is extracted by electrical wires 3 40.

In a domestic installation, the smallest generator 6 will give an output of approximately 1kW from 7 average wind speeds of 4ms'. The generator 30 is 8 approximately 300mm in length by 120mm in diameter.

9 However, any suitable type of generator 30 could be used.

12 The generated electrical energy is passed to control 13 equipment (not shown) to convert the supply to a 14 compatible current. For mains electricity, an inverter converts the supply to a 240v, 50Hz 16 domestic AC supply. For battery systems, a charge 17 controller ensures a constant charge to the battery 18 storage.

The operation of the electrical power generator 10 21 will now be described with reference to Fig. 1. The 22 generator 10 operates under the principle of the 23 Bernoulli's theorem. Therefore, as gas A passes 24 across the gas outlet 20, i.e. perpendicular to the longitudinal axis 16, a low pressure region is 26 created around the gas outlet 20. This creates a 27 differential pressure between the top and bottom 28 portions of the conduit 12. This has the effect of 29 "sucking" gas in the gas inlet 18 and therefore creating a gas flow B through the conduit 12.

I The gas flow through the conduit 12 drives the rotor 2 blades 28 and the drive shaft 32, thus generating 3 electrical energy.

With reference to Fig. 5, the generator 10 may be 6 installed in domestic situations. The generator 10 7 may be built-into the house during construction 8 (indicated by generator A), or retro-fitted to 9 existing houses (indicated by generator B) 11 In industrial applications, the turbine 14 may be 12 installed in locations which are subject to the 13 Bernoulli effect, i.e. lift shafts, service ducts 14 and the like.

16 The generator 10 is not required to be in alignment 17 with the direction of the prevailing wind. As long 18 as gas passes over the gas outlet 20, the resulting 19 gas flow B in the conduit 12 will drive the turbine 14.

22 Although the generator 10 has been described above 23 as being operated by gas passing across the gas 24 outlet 20, is should be appreciated that the generator 10 may also be operated as a result of a 26 temperature gradient created within the conduit 12.

28 For example, as described above, the top portion of 29 the conduit 12 is made from a black body material.

This has the effect of heating the gas located 31 within the top portion of the conduit 12. As the 32 hot gas rises from the conduit 12, cooler gas is 1 sucked in 12 via the gas inlet 18, thus creating a 2 gas flow through the conduit 12 which drives the 3 turbine 14.

Fig. 6 illustrates an alternative arrangement of the 6 generator 10 which is designed to enhance the 7 temperature gradient within the conduit 12. As 8 shown, the conduit 12 has an extended portion 42 9 which is sunk into the ground 44. In this case the gas inlet 18 is located at a position which is 11 remote from the end of the conduit 12. This 12 arrangement is designed to create a geo-thermal heat 13 source at the extended portion 42 of the conduit 12.

14 As the gas in the extended portion 42 is heated it rises, thus aiding the gas flow through the conduit 16 12.

18 An alternative arrangement of the electrical power 19 generator 100 is illustrated in Fig. 7. As shown, the generator 100 may be incorporated into a street 21 light, or the like. The operation of the generator 22 100 is similar to that described above, with the 23 exception that the electrical energy generated is 24 used to power the light 101. The light 101 may comprises a photo- electric switch which turns the 26 light on and off as necessary. During daylight 27 hours, the electrical energy generated may be stored 28 in a storage unit (not shown) . The generator 100 29 may be used in location where there is no mains electricity or on structures such as bridges where 31 supply is difficult.

1 The electrical power generator 10 therefore obviates 2 or mitigates the disadvantages of previous proposals 3 by not relying on the direction of the prevailing 4 wind for operation and not dependent upon strong winds for operation. Furthermore, the generator 10 6 is a relatively simple piece of apparatus which is 7 inexpensive, easy to install and operate, less 8 intrusive and quieter than existing solutions.

Modifications and improvements may be made to the 11 above without departing from the scope of the 12 present invention. For example, although the 13 conduit 12 has been described and illustrated above 14 as being cylindrical, it should be appreciated that the conduit 12 could be any suitable shape which 16 allows gas to flow therethrough.

18 Furthermore, although the generator unit 30 of the 19 turbine 14 has been described above as being located within the conduit 12, it should be appreciated that 21 the generator unit 30 could be located out with the 22 conduit 12. For example, the generator unit 30 23 could be mounted adjacent the conduit 12, with the 24 drive shaft 32 adapted to connect the rotor blades 28 to the generator unit 30 accordingly.

27 Also, although the generator 10 has been described 28 above as being fitted within lift shafts, service 29 ducts, street lights, it should be appreciated that the generator 10 could be fitted at/or within any 31 suitable location, e.g. mobile telephone masts, I radio and TV transmission stations, ships and 2 skyscrapers.

4 Furthermore, the generator 10 could also be used to extract undesirable gases from within buildings.

6 For example, the generator 10 could be used to 7 extract radon gas from buildings. By locating the 8 gas inlet 18 within the chamber to be evacuated, the 9 gas can be extracted out through the gas outlet 20 whilst simultaneously driving the turbine 14.

12 Also, although the conduit 12 has been described 13 above as having a tapered portion along a portion of 14 its length, it should be appreciated that the conduit 12 may be substantially straight.

17 Similarly, although the gas inlet and outlet 18, 20 18 have been described above as funnel shaped, it 19 should be appreciated that the generator 10 may operate without the gas inlet and outlet 18, 20 21 being funnel shaped.

23 Furthermore, although the generator 10 has been 24 described above as operating by passing gas across the gas outlet 20, it should be appreciated that the 26 generator 10 may also operate by passing gas across 27 the gas inlet 18.

Claims

Claims 1. An electrical power generator comprising: a gas conduit, the gas

conduit having a gas inlet and a gas outlet; and a turbine for generating electrical power, the turbine having rotor blades located within the conduit, wherein the gas conduit is adapted to generate a flow of a first gas therethrough upon application of a flow of a second gas across the gas outlet.
2. The electrical power generator of claim 1, wherein the generator further comprises a cap located adjacent the gas outlet.
3. The electrical power generator of claim 2, wherein the cap is an aerofoil.
4. The electrical power generator of any preceding claim, wherein at least a portion of the conduit is tapered along its longitudinal axis.
5. The electrical power generator of any preceding claim, wherein the gas outlet lies in a plane which is substantially perpendicular to the longitudinal axis of the conduit.
6. The electrical power generator of any preceding claim, wherein the gas outlet is in the shape of a funnel.
7. The electrical power generator of any preceding claim, wherein at least an upper portion of the conduit is made from a material in which the absorptance and emissivity are substantially equal to 1.
8. The electrical power generator of any preceding claim, wherein the gas inlet and gas outlet are at opposite ends of the conduit.
9. The electrical power generator of any preceding claim, wherein the gas inlet is located at a position which is remote from the end of the conduit.
10. The electrical power generator of any preceding claim, wherein the gas inlet is in the shape of a funnel.
11. The electrical power generator of any preceding claim, wherein the gas inlet is covered with a grating.
12. The electrical power generator of any preceding claim, wherein the rotor blades are helical.
13. A lighting apparatus comprising: illumination means; and an electrical power generator according to any of claims 1 to 12, wherein the illumination means is powered by the electrical power generator.
14. A method of generating electrical power comprising the steps of: locating the rotor blades of a turbine within a gas conduit having a gas inlet and a gas outlet; and creating a first gas flow through the conduit by passing a second gas across the gas outlet or gas inlet.
15. An electrical power generator as herein before described with reference to figures 1 to 6.
16. A lighting apparatus as herein before described with reference to figure 7.