DE102008043705B4 - Method and flow engine for converting flow energy of a fluid - Google Patents

Abstract

Method for converting flow energy of a fluid, wherein the fluid drives at least one rotor (4, 23, 36, 39, 40) of a flow engine (1, 19, 28, 37) and the rotating rotor (4, 23, 36, 39, 40) by fluid friction in a working fluid in a container (10, 20, 29, 41) which has a cylindrical inner wall (14, 22, 32) and a cylindrical outer wall (15) rotating with respect to the inner wall (14, 22, 32) , performs a mechanical work that is essentially proportional to the flow energy and essentially heats up a flowing heat carrier with the work, characterized in that the rotation in a gap between the inner wall (14, 22, 32) and the outer wall (15) in the Working fluid forms a shear flow and the Joule heat generated by the shear flow heats the heat carrier.

Description

The invention relates firstly to a method for converting fluid flow of a fluid, wherein the fluid drives at least one rotor of a turbomachine, and the rotating rotor by fluid friction in a working fluid in a container having a cylindrical inner wall and a cylindrical outer wall rotating relative to the inner wall essentially performs mechanical work proportional to the flow energy and essentially heats up a flowing heat carrier with the work. Furthermore, the invention relates to a flow engine for converting flow energy of a fluid, with a mast anchored in a foundation and at least one rotatably mounted on the mast rotor, by means of which a substantially constant portion of the flow energy is convertible into rotational energy, and with a converter which a container having a cylindrical inner wall and a rotatable relative to the inner wall cylindrical outer wall, and by means of which the rotational energy of the rotor is substantially convertible into heat and with connections to the converter for supply and discharge of a fluid heat carrier, by means of which the heat from the converter is deductible.

Such methods for converting the flow energy of a fluid into another, technically better usable form of energy are well known. For example, in DE 723 048 A proposed a wind turbine, which generates heat via a water vortex brake, wherein the brake fluid flows through the container and itself serves as a heat transfer medium. Such water vortex brakes have on the inner wall of the container blades which rotate with the axis. The outer wall is provided with fixed walls. In operation, macroscopic vortices form in the direction of rotation of the axis behind the blades and in front of the walls, in which the working fluid heats up as a result of the shear flow. Other wind turbines that generate heat via such water vortex brakes are out DE 30 08 327 A1 and from DE 29 01 997 A1 known.

Widely used fluid power machines for carrying out such methods are equipped with horizontal axis rotors (so-called "windmills"). Increasingly come alternatively vertical axis rotors used, as for example DE 10105570 B4 are known. Opposite horizontal axis rotors are vertical axis rotors by their transverse to the flow direction of rotation axis in operation of this basically independent, so need not be tracked by means of complex technology "into the wind". They are not only mechanically simpler and thus easier to maintain. With their rotor blades not arranged radially, but parallel to the axis of rotation, they are distinguished by a significantly more compact design and are significantly less sensitive to rapidly changing flow velocities and directions.

Flow engines of the aforementioned type are in particular - usually directly to the hub of the rotor - equipped with generators, by means of which the flow energy of the fluid through the rotational energy of the rotor and the hereby performed in the generator mechanical work converted into electrical energy and fed via inverters in the supply network becomes. As a foundation of such flow engines, cast or built earth foundations can be used as well as steel structures, especially for offshore use buoyant so-called "pontoons" or other structures with the required load capacity.

The economy of such flow engines increases almost proportionally with the dependent on the rotor size power: In particular, the generator that converts the rotational energy of the rotor into electrical energy, contributes disproportionately in small wind turbines to the cost of the system.

The smaller the power, the larger - as with photovoltaic systems - the proportion of electrical components in the costs of the system. Wind turbines with low power, for example, for the needs of a family home are therefore generally not economical to operate. The market for such small systems is correspondingly very small.

In the broader context of the invention disclosed JP 57-140573 A a vertical axis rotor which generates heat via an eddy current brake. The eddy current brake runs in a heat transfer medium, through which the heat is dissipated for use.

task

The invention has for its object to simplify the technical use of the flow energy.

solution

Starting from the known method is proposed according to the invention that forms a shear flow through the rotation in a gap between the inner wall and the outer wall in the working fluid and the resulting Scherströmung Joule heat heats the heat carrier, so the rotational energy in heat is converted. Transducer, by means of which Rotation energy is converted into heat, are not only technically much simpler, cheaper and more robust than generators, they can also - for low power - without disproportionate costs are reduced almost arbitrarily.

In addition, with a method according to the invention, the flow energy is provided in the form of energy, which is predominantly needed in smaller units - for example, for residential use - on the one hand and can be stored to others with low losses and economically feasible effort.

In a method according to the invention, the heat transfer medium is a liquid, in particular an oil, water or an emulsion. For higher temperature ranges in particular oils are suitable as a technical heat transfer medium. Water is available in a generally usable quality for technical purposes substantially worldwide at low cost. For example, as a heat transfer medium in a method according to the invention, the heat transfer medium of a - in particular also in parallel - solar collector can be used.

According to the invention, the rotor performs the work by fluid friction in a working fluid. For example, a transducer may have a shaft stub driven by the rotor in a cup-shaped cavity of the mast, wherein the shear viscosity of the working fluid in a gap between the walls of the stub shaft and the cavity determines the energy absorbable by the transducer. The resistance of this arrangement against rotation and thus the energy absorbed by the transducer - can be enhanced by targeted structuring of the walls.

As a working fluid, the flowing heat carrier can be used in such a converter. Alternatively, the working space of the transducer in which the working fluid is heated, be separated from the heat carrier. The heat transfer medium then does not conduct the heat directly from the working fluid, but rather via a heat exchanger, for example from an outer surface of the cup-shaped cavity described above, out of the converter.

Alternatively or additionally, eddy currents can be induced in a converter by relative movement relative to permanent magnets in an electrical conductor. For example, a copper coating of a shaft stub driven by the rotor between permanent magnets in a wall of the cup-shaped cavity of the mast as an ohmic load can convert the rotational energy into Joule heat.

Preferably, the heat carrier heats a heat storage. The heat recovered from the flow energy can then be stored for later use and retrieved, for example via a heating system. Alternatively, the heat can be used directly for heating, for example, a living space.

Starting from the known flow engines is proposed according to the invention to provide a gap between the inner wall and the outer wall, in which forms a shear flow through the rotation in a working fluid, wherein the heat generated by the Scherströmung Joule heat heats the heat carrier. A turbomachine according to the invention makes it possible to carry out one of the above-described methods according to the invention and is distinguished by the advantages described therefor.

Particularly preferably, the rotor is a vertical axis rotor on a turbomachine according to the invention. Vertical axis rotors are not only technically simpler and more robust than - in principle, also usable - horizontal axis rotors, but are also suitable by the vertical axis especially for combination with a coaxial with the mast arranged transducer.

On such a turbomachine according to the invention, a common transducer between two counterrotatable vertical axis rotors may be arranged, for example - in the above-described arrangement with heating of a working fluid by fluid friction - the lower of these vertical axis rotors the cup and the upper drives the stub shaft.

Advantageously, a turbomachine according to the invention has a control element by means of which the conversion of the rotational energy into heat can be regulated as a function of the speed. In the above-described arrangements (with fluid friction or Ohm's consumer), the resistance of the converter to rotation is already fundamentally speed-dependent.

In addition, the resistance of the transducer to rotation is proportional to the effectively opposing surfaces (e.g., the cup and the stub shaft). A regulation - in particular for a start-up phase of the flow engine according to the invention - can therefore take place via the immersion depth (of the stub shaft into the working fluid or between the permanent magnets).

The immersion depth can be controlled, for example, electrically or - purely mechanically - via a centrifugal governor. In the above In addition, as described with heating a working fluid by fluid friction, the immersion depth can be increased by increasing the amount of the working fluid. Alternatively, or additionally, the immersion depth can also be set manually on a turbomachine according to the invention.

embodiments

The invention is explained below with reference to exemplary embodiments:

1 a first flow engine according to the invention,

2 a second flow engine according to the invention,

3 a third inventive flow engine and

4 a fourth flow engine according to the invention.

In the 1 sketched first flow engine according to the invention 1 has a mast 2 on, on a foundation 3 is anchored. At the mast 2 is a rotor 4 with a diameter 5 of 1 m and a height 6 of 80 cm rotatable attached.

The rotor 4 is a vertical axis rotor with three rigidly interconnected between a base plate 7 and a lid 8th attached, with a constant profile parallel to the mast 2 extending rotor blades 9 for speeds up to 500 / min. basal disc 7 and lid 8th are in (not shown) bearing elements on the mast 2 radially mounted. The foot disk 7 is in addition to the mast 2 axially stored.

Below the rotor blades 9 is with the foot washer 7 a cylindrical container 10 firmly connected, one area 11 of the mast 2 embraces. A floor 12 of the container 10 has a circular opening 13 on top of that, the mast 2 penetrates. At the circle opening 13 is the container 10 opposite the mast 2 completed fluid-tight by means of a labyrinth seal, not shown. Inside the container 10 is with the mast 2 an inner wall 14 of the container 10 rigidly connected. The outer wall 15 and the inner wall 14 of the container 10 have a (in the figure disproportionately enlarged) shown gap distance.

Through the mast 2 is a connection 16 for the supply of a heat transfer emulsion in the container 10 and another connection 17 for the discharge from the container 10 guided. In operation of the turbomachine 1 becomes the container 10 through the connection 16 For the supply line continuously charged with a heat transfer medium, which is continuously through the connection 17 for the derivative runs out again.

By the rotation of the outer wall 15 opposite the fixed inner wall 14 of the container 10 a shear flow forms between the two, which superimposes the flow of the heat carrier between the connections. The Joule heat produced by the shear flow heats up the heat transfer medium.

To reduce the shear resistance in the heat transfer medium and so the start of the flow engine 1 To facilitate, the level becomes 18 of the heat carrier in the tank 10 until the connection 17 lowered for the derivative. To switch off the flow engine 1 is the rotor 4 equipped with not shown, electrically and mechanically switchable friction brakes.

A not shown arrangement of five flow engines according to the invention 1 supports in addition to a collector system, the heating of a detached house. The masts 2 the turbomachinery 1 are anchored side by side on the ridge of the family house. The roof truss of the family house serves as a foundation 3 the turbomachinery 1 , From the flow engines of the invention 1 leaking heat transfer medium is led in each case into a common collector and from there into a storage in the cellar of the single-family dwelling. A common control of the heating system distributes the heat transfer medium depending on the solar radiation, wind speed and heat demand on the collectors and the flow engines according to the invention 1 ,

In the 2 sketched alternative flow engine according to the invention 19 is different from the first turbomachine 1 only by the arrangement of the container 20 : The container 20 is rigid with the mast 21 , an interior wall 22 of the container 20 with the rotor 23 connected. The inner wall 22 points in a ground 24 one opposite the mast 21 with a (not shown) sealed bearing fluid-tight closed circular opening 25 on. The connection 26 for the supply line and the connection 27 for the discharge of the heat carrier are from the outside to the container 20 guided.

Also in 3 outlined third flow engine according to the invention 28 is different from the first turbomachine 1 only by the arrangement of the container 29 : The container 29 is between the foot disk 30 and the lid 31 trained, the inner wall 32 is - like the first turbomachine 1 - rigid with the mast 33 connected and opposite the foot disk 30 that at the same time the ground 34 of the container 29 represents, again with a labyrinth seal 35 sealed fluid-tight. By integrating the container 29 in the rotor 36 is the height of the flow engine 28 reduced.

In the 4 sketched fourth flow engine according to the invention 37 has opposite to the previously described on a mast 38 one above the other two rotors rotatable in opposite directions 39 . 40 on. The container 41 is with the lid 42 of the lower rotor 39 , a perforated partition 43 with the foot disk 44 of the upper rotor 40 and an inner wall with the mast 38 rigidly connected. The inner wall, through which also the connection 45 for the supply of the heat carrier in the container 41 and the connection 46 for the discharge from the container 41 are guided, is opposite the lid 42 of the lower rotor 39 - this is the ground here 47 of the container 41 forms - again sealed fluid-tight with a labyrinth seal. The inner wall and the labyrinth seal are not shown simplifying.

LIST OF REFERENCE NUMBERS

1

Flow engine

2

mast

3

foundation

4

rotor

5

diameter

6

height

7

basal disc

8th

cover

9

rotor blade

10

container

11

Area

12

ground

13

circular opening

14

inner wall

15

outer wall

16

connection

17

connection

18

level

19

Flow engine

20

container

21

mast

22

inner wall

23

rotor

24

ground

25

circular aperture

26

connection

27

connection

28

Flow engine

29

container

30

basal disc

31

cover

32

inner wall

33

mast

34

ground

35

labyrinth seal

36

rotor

37

Flow engine

38

mast

39

rotor

40

rotor

41

container

42

cover

43

partition

44

basal disc

45

connection

46

connection

47

ground

Claims (5)

Method for converting the flow energy of a fluid, wherein the fluid comprises at least one rotor ( 4 . 23 . 36 . 39 . 40 ) of a flow engine ( 1 . 19 . 28 . 37 ) and the rotating rotor ( 4 . 23 . 36 . 39 . 40 by fluid friction in a working fluid in a container ( 10 . 20 . 29 . 41 ), which has a cylindrical inner wall ( 14 . 22 . 32 ) and one opposite the inner wall ( 14 . 22 . 32 ) rotating cylindrical outer wall ( 15 ) performs a substantially the flow energy proportional mechanical work and heats the work essentially a flowing heat carrier, characterized in that by the rotation in a gap between the inner wall ( 14 . 22 . 32 ) and the outer wall ( 15 ) forms a shear flow in the working fluid and the Joule heat produced by the shear flow heats the heat transfer medium. Method according to the preceding claim, characterized in that the heat carrier heats a heat storage. Flow engine ( 1 . 19 . 28 . 37 ) for converting the flow energy of a fluid, with one at a foundation ( 3 ) moorable mast ( 2 . 21 . 33 . 38 ) and at least one on the mast ( 2 . 21 . 33 . 38 ) rotatably mounted rotor ( 4 . 23 . 36 . 39 . 40 ), by means of which a substantially constant portion of the flow energy is convertible into rotational energy, and with a transducer, which a container ( 10 . 20 . 29 . 41 ) with a cylindrical inner wall ( 14 . 22 . 32 ) and one opposite the inner wall ( 14 . 22 . 32 ) rotatable cylindrical outer wall ( 15 ), and by means of which the rotational energy of the rotor ( 4 . 23 . 36 . 39 . 40 ) is substantially convertible into heat and with connections ( 16 . 26 . 45 . 17 . 27 . 46 ) on the converter for supply and discharge of a fluid heat carrier, by means of which the heat can be dissipated from the converter, characterized by a gap between the inner wall ( 14 . 22 . 32 ) and the outer wall ( 15 ), in which forms by the rotation in a working fluid, a shear flow, wherein the through the Scherströmung resulting Joule'sche heat heats the heat transfer medium. Flow engine ( 1 . 19 . 28 . 37 ) according to the preceding claim, characterized in that the rotor ( 4 . 23 . 36 . 39 . 40 ) is a vertical axis rotor. Flow engine ( 1 . 19 . 28 . 37 ) according to one of claims 3 or 4, characterized by a control element, by means of which the conversion of the rotational energy in Wähne is speed-dependent regulated.

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