阅读说明：本技术 流体流动转换器 (Fluid flow converter ) 是由 丹尼尔·埃恩贝格 于 2019-02-01 设计创作，主要内容包括：一种用于将旋转转换为流体流动的设备,该设备包括：流体导管,该流体导管绕旋转轴线盘绕,该流体导管具有用于接纳具有第一密度的第一流体的第一入口和用于接纳具有第二密度的第二流体的第二入口以及用于输出第一流体的第一出口和用于输出第二流体的第二出口；马达,该马达联接至流体导管以使流体导管绕旋转轴线沿第一角度方向旋转,使得第一流体的第一流体部分和第二流体的第二流体部分被沿着流体导管朝向第一出口输送,同时被加压；流体返回装置,该流体返回装置将第二出口和第二入口流体流动连接,从而选择性地允许加压的第二流体从第二出口返回至第二入口,同时使加压的第二流体减压。(An apparatus for converting rotation into fluid flow, the apparatus comprising: a fluid conduit coiled about an axis of rotation, the fluid conduit having a first inlet for receiving a first fluid having a first density and a second inlet for receiving a second fluid having a second density and a first outlet for outputting the first fluid and a second outlet for outputting the second fluid; a motor coupled to the fluid conduit to rotate the fluid conduit in a first angular direction about the axis of rotation such that a first fluid portion of the first fluid and a second fluid portion of the second fluid are conveyed along the fluid conduit toward the first outlet while being pressurized; a fluid return fluidly connecting the second outlet and the second inlet to selectively allow the pressurized second fluid to return from the second outlet to the second inlet while depressurizing the pressurized second fluid.)

1. A device (1; 100) for converting rotation into fluid flow, the device comprising:

a fluid conduit (3) coiled about an axis of rotation (5), the fluid conduit having a first inlet (7; 107) for receiving a first fluid having a first density and a second inlet (9a-9 b; 107) for receiving a second fluid having a second density different from the first density, and a first outlet (11; 111) for outputting the first fluid and a second outlet (11; 111) for outputting the second fluid;

a motor (65) coupled to the fluid conduit (3) to rotate the fluid conduit in a first angular direction (67) about the rotation axis (5) such that a first fluid portion of a first fluid and a second fluid portion of a second fluid are conveyed along the fluid conduit (3) towards the first outlet (11; 111) while being pressurized; and

a fluid return arrangement (19; 119) fluidly connecting the second outlet (11; 111) and the second inlet (9a-9 b; 107) to selectively allow pressurized second fluid to return from the second outlet (11; 111) to the second inlet (9a-9 b; 107) while depressurizing the pressurized second fluid.

2. The device (1; 100) according to claim 1, wherein:

the fluid conduit (3) further having a third outlet (13; 113) arranged along the fluid conduit between the second inlet (9a-9 b; 107) and the second outlet (11; 111) for outputting a second fluid; and is

The fluid return means (19; 119) fluidly connects the third outlet (13; 113) and the second inlet (9a-9 b; 107) for selectively allowing pressurized second fluid to return from the third outlet (13; 113) to the second inlet (9a-9 b; 107) while depressurizing the pressurized second fluid.

3. The apparatus of claim 1 or 2, wherein the fluid return device comprises a pressure reduction device having an actuator, the pressure reduction device configured to:

receiving the pressurized second fluid;

causing the pressurized second fluid to perform work on the actuator, thereby causing movement of the actuator, thereby causing the pressurized second fluid to be depressurized; and is

Outputting the reduced pressure second fluid.

4. The apparatus of claim 3, wherein the fluid return device comprises a fluid return conduit,

the actuator is arranged to move relative to the fluid return conduit as a result of interaction with the second fluid.

5. The apparatus of claim 3 or 4, further comprising a translation device coupled to the actuator and configured to translate movement of the actuator into rotation of the fluid conduit in the first angular direction.

6. The apparatus of claim 5, the transition device mechanically coupling the actuator to the fluid conduit such that movement of the actuator causes the fluid conduit to rotate in the first angular direction.

7. The apparatus of any of claims 3-6, wherein the pressure reduction device comprises at least one of a turbine, a pump, and a piston.

8. An apparatus for converting rotation into fluid flow, the apparatus comprising:

a fluid conduit coiled about an axis of rotation, the fluid conduit having a first inlet for receiving a first fluid having a first density and a second inlet for receiving a second fluid having a second density different from the first density and a first outlet for outputting the first fluid and a second outlet for outputting the second fluid,

the fluid conduit is rotatable about the axis of rotation in a first angular direction such that a first fluid portion of the first fluid and a second fluid portion of the second fluid are conveyed along the fluid conduit toward the first outlet while being pressurized; and

a fluid return fluidly connecting the second outlet and the second inlet to selectively allow pressurized second fluid to return from the second outlet to the second inlet while depressurizing the pressurized second fluid,

wherein the fluid return device includes a pressure reduction device having an actuator, the pressure reduction device configured to:

receiving the pressurized second fluid;

causing the pressurized second fluid to perform work on the actuator, thereby causing movement of the actuator, thereby depressurizing the pressurized second fluid; and is

Outputting the second fluid with the reduced pressure,

wherein the apparatus further comprises a translation device coupled to the actuator and configured to translate movement of the actuator into rotation of the fluid conduit in the first angular direction.

9. An apparatus according to any preceding claim, wherein the apparatus further comprises a first flow control device controllable to prevent or allow fluid to flow between the fluid conduit and the fluid return device through the second outlet.

10. The apparatus of claim 9, wherein:

the first flow control device is an electrically controllable flow control device; and is

The apparatus further comprises a control circuit having an input for receiving a signal indicative of the angular position of the second outlet and at least a first output for providing a first control signal to the flow control device to allow flow from the fluid conduit to the fluid return device through the second outlet when the second outlet is within a predetermined first angular range.

11. The apparatus of claim 9, wherein:

the first flow control device is a mechanically actuated flow control device; and is

The apparatus further comprises an actuation device arranged to move in response to rotation of the fluid conduit and arranged to interact with the first flow control device to allow flow from the fluid conduit to the fluid return device through the second outlet when the second outlet is within a predetermined first angular range.

12. Apparatus according to any preceding claim, wherein the fluid return means comprises a fluid return conduit connected to the second inlet.

13. The apparatus (100) according to claim 1, wherein the fluid conduit (3) further has a third inlet (121) arranged along the fluid conduit between the second inlet (107) and the second outlet (111) for receiving a first fluid.

14. The apparatus (100) of claim 13, wherein the fluid return device (119) comprises a container (129) having: a first container inlet (137) connected to the second outlet (111) of the fluid conduit (3) for receiving a pressurized second fluid from the second outlet (111) of the fluid conduit; a first container outlet (139) connected to the third inlet (121) of the fluid conduit for providing a pressurized first fluid to the third inlet (121) of the fluid conduit; and a second container outlet (143) connected to the second inlet (107) of the fluid conduit so as to provide a reduced pressure second fluid to the second inlet (107) of the fluid conduit.

15. The apparatus (100) according to claim 13, wherein the fluid conduit (3) further has: a third outlet (113) arranged along the fluid conduit (3) between the second inlet (107) and the second outlet (111) for outputting a second fluid; and a fourth inlet (123) arranged along the fluid conduit between the second outlet (111) and the second inlet (107) for receiving a first fluid.

16. The apparatus of claim 15, wherein the fourth inlet is disposed along the fluid conduit between the third outlet and the second inlet for receiving a first fluid.

17. Apparatus according to claim 15 or 16, wherein the fluid return device (119) further comprises a container (131) having a first container inlet connected to the third outlet (113) of the fluid conduit for receiving a pressurized second fluid from the third outlet of the fluid conduit; a first container outlet connected to the fourth inlet (123) of the fluid conduit so as to provide pressurized first fluid to the fourth inlet of the fluid conduit; and a second container outlet connected to the second inlet (107) of the fluid conduit so as to provide a reduced pressure second fluid to the second inlet (107) of the fluid conduit.

18. The apparatus of claim 14 or 17, wherein:

the container is configured to receive a first fluid when a depressurized second fluid is provided to the second inlet (107) of the fluid conduit.

19. An apparatus for converting fluid flow into rotation, the apparatus comprising: a fluid conduit coiled about an axis of rotation, the fluid conduit having a first inlet for receiving a first fluid having a first density and a second inlet for receiving a second fluid having a second density different from the first density and a first outlet for outputting the first fluid and a second outlet for outputting the second fluid,

wherein the apparatus is configured such that: supplying a pressurized first fluid portion to the first inlet and a pressurized second fluid portion to the second inlet causes the fluid conduit to rotate about the axis of rotation and the first and second fluid portions to be delivered toward the first outlet while being depressurized; and is

Wherein the apparatus further comprises a fluid return arrangement fluidly connecting the second outlet and the second inlet to selectively allow the reduced-pressure second fluid to return from the second outlet to the second inlet while pressurizing the reduced-pressure second fluid.

20. The apparatus of claim 19, wherein the fluid return device comprises a pressurization device having an actuator, the pressurization device configured to:

receiving the reduced pressure second fluid;

converting motion of the actuator into work acting on the second fluid to pressurize the second fluid; and is

The output of the pressurized second fluid is provided,

wherein the apparatus further comprises a conversion device coupled to the actuator and configured to convert rotation of the fluid conduit into movement of the actuator.

21. The apparatus of claim 20, the transition device mechanically couples the actuator to the fluid conduit such that rotation of the fluid conduit causes movement of the actuator.

22. The apparatus of claim 19, wherein the fluid conduit further has a third inlet disposed along the fluid conduit between the first inlet and the first outlet for receiving a second fluid.

23. The apparatus of claim 22, wherein the fluid return device comprises a container having: a first container inlet connected to the second outlet of the fluid conduit for receiving a reduced-pressure second fluid from the second outlet of the fluid conduit; a second vessel inlet for receiving a pressurized first fluid; and a first container outlet connected to the third inlet of the fluid conduit for providing a pressurized second fluid to the third inlet of the fluid conduit.

24. The apparatus of claim 22, wherein the fluid conduit further has a fourth inlet disposed along the fluid conduit between the second inlet and the second outlet for receiving a second fluid.

25. The apparatus of claim 19, wherein the fluid conduit further has a third outlet disposed along the fluid conduit between the first inlet and the first outlet for outputting a first fluid.

26. The apparatus of claim 25, wherein the fluid return device comprises a container having: a first container inlet connected to the second outlet of the fluid conduit for receiving a reduced-pressure second fluid from the second outlet of the fluid conduit; a second container inlet connected to the third outlet of the fluid conduit for receiving a first fluid from the fluid conduit; and a first container outlet connected to the fourth inlet of the fluid conduit so as to provide a pressurized second fluid to the fourth inlet of the fluid conduit.

27. The apparatus of any one of the preceding claims, wherein the apparatus further comprises a temperature control device to cool or heat the first or second fluid.

Technical Field

The present invention relates to an apparatus and a method for converting rotation into fluid flow and an apparatus and a method for converting fluid flow into rotation.

Background

It has long been known to pump water or compressed air using devices that rely on coiled tubing that alternately allows air and water to enter the tubing rotating about an axis of rotation. Such devices have fewer moving parts and are considered to be relatively simple and reliable.

For example, GB 1427723 discloses an apparatus for pumping fluid comprising a tube of constant cross-section arranged around a cylindrical structure with a certain number of turns so as to form a cylindrically shaped coil. One end of the coiled tubing is connected to the hollow shaft of the apparatus, while the other end of the coiled tubing terminates at the periphery of the cylindrical structure and is open to the atmosphere. As the cylindrical structure rotates, water and air are alternately admitted to the open end of the tube and delivered to the hollow shaft.

WO 2016/080902 discloses a more energy efficient device wherein, according to an embodiment, one coiled fluid conduit, i.e. a pressure increasing fluid conduit, is used for achieving a gradual increase of the pressure of the first fluid and the second fluid, and one coiled fluid conduit, i.e. a pressure decreasing fluid conduit, is used for returning the first fluid and the second fluid while achieving a gradual decrease of the pressure.

There still seems to be room for improvement. In particular, it would be desirable to provide a more compact and/or cost effective apparatus for converting rotation into fluid flow and/or fluid flow into rotation.

Disclosure of Invention

In view of the above, it is an object of the present invention to achieve an improved conversion of rotation to fluid flow and/or an improved conversion of fluid flow to rotation.

Thus, according to a first aspect of the present invention, there is provided an apparatus for converting rotation into fluid flow, the apparatus comprising: a fluid conduit coiled about an axis of rotation, the fluid conduit having a first inlet for receiving a first fluid having a first density and a second inlet for receiving a second fluid having a second density different from the first density and a first outlet for outputting the first fluid and a second outlet for outputting the second fluid; a motor coupled to the fluid conduit to rotate the fluid conduit in a first angular direction about the axis of rotation such that a first fluid portion of the first fluid and a second fluid portion of the second fluid are conveyed along the fluid conduit toward the first outlet while being pressurized; and a fluid return fluidly connecting the second outlet and the second inlet to selectively allow the pressurized second fluid to return from the second outlet to the second inlet while depressurizing the pressurized second fluid.

A fluid is any flowing substance. Thus, a fluid includes, for example, a gas, a liquid, and solid particles suspended in the liquid, for example, to form a particle suspension exhibiting fluid properties.

It will be appreciated that the first and second inlets may be provided as separate inlets or as a common inlet. Similarly, the first and second outlets may be provided as separate outlets or as a common outlet.

The fluid conduit does not necessarily have to be a coiled tube but may be constructed in many other ways as long as the fluid path is coiled such that a projection of the fluid path forms a helix.

When both the first fluid and the second fluid having different densities are present inside the coiled fluid conduit, the equilibrium state of the coiled fluid conduit at rest and without pressure differentials will be where the combined center of mass of the first fluid and the second fluid is directly below the axis of rotation of the coiled fluid conduit. As the coiled fluid conduit rotates against the ram, the combined center of mass shifts along the coiled fluid conduit corresponding to the increasing pressure inside the coiled fluid conduit. The offset combined center of mass in the coiled fluid conduit of increased pressure will exert a torque on the coiled fluid conduit. A torque of opposite sign greater than that caused by the centroid shift would need to be provided (by the electric motor) to the coiled fluid conduit of increased pressure to maintain rotation.

In order to deliver a first fluid from a first inlet to a first outlet while maintaining closed loop operation with respect to a second fluid, the present inventors have recognized that it would be desirable to provide a fluid return device that fluidly connects the second outlet and the second inlet and is configured to selectively allow the pressurized second fluid to return to the second inlet while depressurizing the pressurized second fluid.

The fluid return means being configured to selectively allow return of the pressurised second fluid should be understood to mean that the fluid return means is configured to prioritise the return of the pressurised second fluid over any return of the pressurised first fluid. For example, the fluid return device may be configured to maintain a proportion by volume of the pressurized second fluid passing from the fluid conduit to the fluid return device at the second outlet above at least 80%. Advantageously, the fluid return means may be configured to maintain the volume fraction above 90%.

According to various embodiments, the fluid return device may comprise a pressure reduction device having an actuator, the pressure reduction device being configured to: receiving a pressurized second fluid; causing the pressurized second fluid to perform work on the actuator, thereby causing movement of the actuator, thereby depressurizing the pressurized second fluid; and outputting the reduced pressure second fluid.

The fluid return arrangement may comprise a fluid return conduit and the actuator may be arranged to move relative to the fluid return conduit as a result of interaction with the second fluid.

The pressure reduction device may be any device that can convert a pressure drop into work. Examples of suitable pressure reducing devices include turbines, pumps, and pistons.

The above-mentioned actuator may be a linear actuator, such as a piston, or a rotary actuator, such as a shaft.

By providing a pressure reduction means, the energy released when depressurizing the pressurized second fluid can be used by exercising the movement of the actuator.

According to an embodiment, the translation device may be coupled to the actuator and configured to translate movement of the actuator into rotation of the fluid conduit in the first angular direction. The conversion device may be mechanically coupled to the fluid conduit, or the conversion device may comprise a generator in which the above-mentioned actuator is coupled to the rotor to cause the generator to generate electrical power which may be used to assist in driving rotation of the fluid conduit about the axis of rotation in the first rotational direction.

In some embodiments, the switch device may mechanically couple the actuator to the fluid conduit such that movement of the actuator causes the fluid conduit to rotate in a first angular direction.

According to a second aspect of the present invention there is provided an apparatus for converting rotation into fluid flow, the apparatus comprising: a fluid conduit coiled about an axis of rotation, the fluid conduit having a first inlet for receiving a first fluid having a first density and a second inlet for receiving a second fluid having a second density different from the first density and a first outlet for outputting the first fluid and a second outlet for outputting the second fluid, the fluid conduit being rotatable about the axis of rotation in a first angular direction such that a first fluid portion of the first fluid and a second fluid portion of the second fluid are conveyed along the fluid conduit towards the first outlet while being pressurized; and a fluid return arrangement fluidly connecting the second outlet and the second inlet to selectively allow the pressurized second fluid to return from the second outlet to the second inlet while depressurizing the pressurized second fluid, wherein the fluid return arrangement includes a pressure reduction arrangement having an actuator, the pressure reduction arrangement configured to: receiving a pressurized second fluid; causing the pressurized second fluid to perform work on the actuator, thereby causing movement of the actuator, thereby depressurizing the pressurized second fluid; and outputting the reduced pressure second fluid, wherein the apparatus further comprises a translation device coupled to the actuator and configured to translate movement of the actuator into rotation of the fluid conduit in the first angular direction.

It is to be understood that the following description and illustrations of the various embodiments of the invention apply to all aspects of the invention.

According to an embodiment, the first flow control means may be arranged to control the flow of fluid between the fluid conduit and the fluid return means through the second outlet. By means of the first flow control means, which may be a first controllable valve, the second fluid may only be sent out of the fluid conduit through the second outlet during selected time periods. This may provide for more efficient operation of the apparatus according to the different aspects of the invention.

The first flow control means may be a controllable valve, such as a controllable check valve. The first flow control means may be mechanically or electrically controllable. It should be noted that the first flow control means does not have to be arranged at the second outlet, but may be arranged at another position between the second outlet and the second inlet, as long as the first flow control means is controllable to prevent or allow a fluid flow through the second outlet.

According to an embodiment, the first flow control device may be an electrically controllable flow control device; and the apparatus may further comprise a control circuit having an input for receiving a signal indicative of the angular position of the second outlet, and at least a first output for providing a first control signal to the flow control device to allow flow from the fluid conduit to the fluid return device through the second outlet only when the second outlet is within a predetermined first angular range.

The signal indicating the angular position may for example come from an angle sensor comprised in the device.

Alternatively, the first flow control means may be mechanically controllable, e.g. mechanically controllable by a cam arrangement, and the apparatus may comprise a mechanical arrangement (cam arrangement) arranged to control the flow control means to allow flow from the fluid conduit to the fluid return means through the second outlet only when the second outlet is within a predetermined first angular range.

Furthermore, according to various embodiments, the fluid conduit may further have a third outlet arranged along the fluid conduit between the second inlet and the second outlet for outputting the second fluid; and the fluid return arrangement may fluidly connect the third outlet and the second inlet to selectively allow the pressurized second fluid to return from the third outlet to the second inlet while depressurizing the pressurized second fluid.

The provision of the third outlet allows the second fluid to be returned from another location along the fluid conduit which provides for more efficient operation and/or allows the use of a longer fluid conduit and/or higher pressure and/or compression ratio of the first fluid at the first outlet.

Advantageously, the apparatus of the different aspects of the invention may further comprise a second flow control device arranged to control the flow of fluid between the fluid conduit and the fluid return device through the third outlet.

Further, the fluid conduit may have a third inlet for receiving the second fluid and a third outlet for outputting the second fluid; and the fluid return arrangement may fluidly connect the third outlet and the third inlet to selectively allow the pressurized second fluid to return from the third outlet to the third inlet while depressurizing the pressurized second fluid.

The third inlet may be disposed along the fluid conduit between the first inlet and the second inlet. By this configuration, the pressurized second fluid may be returned to different positions along the fluid conduit step by step, which achieves a further improved efficiency of the device.

In an embodiment, the second inlet and the third outlet may be provided as a common inlet-outlet port. In such an embodiment, the first flow control means mentioned above may advantageously be arranged to control the flow of fluid between the fluid conduit and the fluid return means through a common inlet-outlet port.

The apparatus may include a control unit connected to the first flow control device and configured to control the first flow control device to allow the reduced-pressure second fluid from the second inlet to flow from the fluid return to the fluid conduit through the common inlet-outlet port during a first time period, and configured to control the first flow control device to allow the pressurized second fluid to flow from the fluid conduit toward the third inlet to the fluid return through the common inlet-outlet port during a second time period. The second time period may be different from the first time period.

Furthermore, according to various embodiments, the first outlet and the second outlet may be provided as a common outlet; and the fluid return means may comprise a fluid separator for separating the first fluid from the second fluid.

The first fluid and the second fluid may be immiscible. For example, the first fluid may advantageously be a gas, such as air, and the second fluid may advantageously be a liquid, such as water.

According to various embodiments, the fluid conduit from the first inlet may be coiled around the rotation axis for at least a first and a last revolution; and the first revolution may be located at a greater radial distance from the axis of rotation than the last revolution.

According to a third aspect of the present invention there is provided apparatus for converting fluid flow into rotation, the apparatus comprising: a fluid conduit coiled about an axis of rotation, the fluid conduit having a first inlet for receiving a first fluid having a first density and a second inlet for receiving a second fluid having a second density different from the first density and a first outlet for outputting the first fluid and a second outlet for outputting the second fluid; wherein the apparatus is configured such that: supplying the pressurized first fluid portion to the first inlet and the pressurized second fluid portion to the second inlet rotates the fluid conduit about the axis of rotation and transports the first and second fluid portions toward the first outlet while being depressurized; and wherein the apparatus further comprises a fluid return arrangement fluidly connecting the first outlet and the first inlet to selectively allow the reduced-pressure second fluid to return from the second outlet to the second inlet while pressurizing the reduced-pressure second fluid.

According to an embodiment, the fluid return device may comprise a pressurizing device having an actuator, the pressurizing device being configured to: receiving a reduced pressure second fluid; converting the motion of the actuator into work acting on the second fluid to pressurize the second fluid; and outputting the pressurized second fluid, wherein the apparatus further comprises a conversion device coupled to the actuator and configured to convert rotation of the fluid conduit into movement of the actuator.

In summary, according to various embodiments, the present invention relates to a device for converting rotation into fluid flow and/or fluid flow into rotation. The apparatus comprises a fluid conduit coiled about an axis of rotation, the fluid conduit having a first inlet for receiving a first fluid having a first density and a second inlet for receiving a second fluid having a second density different from the first density, and a first outlet for outputting the first fluid and a second outlet for outputting the second fluid. The apparatus also includes a fluid return device fluidly connecting the second outlet and the second inlet to selectively allow the second fluid to return from the second outlet to the second inlet.

Drawings

These and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing exemplary embodiments of the invention, wherein:

figure 1 is a schematic perspective view of an apparatus comprising a piston arrangement in the form of a free-standing compressor/air motor according to a first example embodiment of the invention;

FIG. 2 is a diagram schematically illustrating an example operation of the apparatus of FIG. 1;

FIG. 3 is a schematic illustration of a rotational alternative to the piston of FIG. 1; and

fig. 4A to 4B are schematic perspective views of an apparatus according to a second exemplary embodiment of the present invention.

Detailed Description

In this detailed description, various embodiments of the apparatus and method according to the present invention are described primarily with reference to an apparatus for converting rotation into fluid flow and/or converting fluid flow into rotation by using water as the second fluid and air as the first fluid.

It should be noted that this in no way limits the scope of the invention, which for example also includes devices that operate by using other combinations of first and second fluids having different densities. Operations with more than two different fluids are also envisioned.

Fig. 1 schematically illustrates an apparatus according to a first example embodiment of the invention in the form of a standalone compressor/air motor 1. The compressor/air motor 1 is a device that can be operated in two modes of operation: a first mode in which rotation is converted to fluid (air) flow; and a second mode in which the flow of pressurized fluid (air) is converted into rotation.

The above-mentioned first operation mode will be described in detail herein. The second operation mode mentioned above relates only to running the device "backwards" compared to the first operation mode. This means that certain fluid ports that are "inlets" in the first mode will be "outlets" in the second mode, and certain fluid ports that are "outlets" in the first mode will be "inlets" in the second mode. This also means that the electric motor in the first operation mode is a generator in the second operation mode.

The compressor/air motor 1 comprises a fluid conduit 3 coiled about a rotational axis 5. As schematically shown in fig. 1, the fluid conduit 3 has a first inlet 7 for receiving a first fluid (here air), a second inlet 9a-9b for receiving a second fluid (here water), a first outlet and a second outlet, here provided as a common outlet 11 for outputting air and water. In the exemplary embodiment of fig. 1, the fluid conduit 3 additionally has a third outlet 13 for outputting water, a fourth outlet 15 for outputting water and a fifth outlet 17 for outputting water.

The apparatus 1 further comprises a fluid return device 19, which fluid return device 19 is configured to allow pressurized water to return from the outlet to the inlet while depressurizing the pressurized water.

As can be observed from fig. 1, the fluid return device 19 according to the exemplary embodiment of fig. 1 comprises a pressure reduction device in the form of: a piston device 21; a first fluid return conduit 23, the first fluid return conduit 23 connecting the second outlet (common outlet 11), the third outlet 13, the fourth outlet 15 and the fifth outlet 17 with the first inlet 25 and the second inlet 27 of the piston means 21; and a second fluid return conduit 29 and a third fluid return conduit 31, the second fluid return conduit 29 and the third fluid return conduit 31 connecting the first outlet 33 and the second outlet 35 of the piston device 21 with the second inlets 9a to 9 b.

The piston means 21 comprises an actuator in the form of a piston 37, which piston 37 is arranged to move linearly (non-uniformly) inside a cylinder 39 between a first radial position and a second radial position, wherein the second radial position is further away from the axis of rotation 5 than the first radial position.

The fluid return arrangement 19 in the example apparatus 1 of fig. 1 further comprises a fluid separator 41, which fluid separator 41 is arranged to receive alternating batches (alternate batches) of pressurized air and pressurized water from the common outlet 11. By configuring the apparatus 1 such that the axis of rotation 5 forms an angle α (a few degrees may be sufficient) with the horizontal plane 43, pressurized air may be separated from pressurized water, as schematically indicated in fig. 1.

In fig. 1, it is also noted that the fluid separator 41 is offset with respect to the axis of rotation 5. By placing the fluid separator 41 close to the inner side of the fluid conduit 3, water and air may enter directly into the fluid separator 41 through a common outlet. The rotor shaft, which keeps the rotor centered, does not have to pass through the fluid separator 41 and the fluid separator can be made smaller. This enables a lighter device, which may be important for convenient installation, and which may enable more energy efficient operation of the device.

In order to allow the control of the return of the pressurized second fluid, the fluid return device 19 further comprises: a first controllable valve 45 between the second outlet 11 and the first fluid return conduit 23, a second controllable valve 47 between the third outlet 13 and the first fluid return conduit 23, a third controllable valve 49 between the fourth outlet 15 and the first fluid return conduit 23, a fourth controllable valve 51 between the fifth outlet 17 and the first fluid return conduit 23, a fifth controllable valve 53 between the first fluid return conduit 23 and the cylinder 39 proximate to the first radial position mentioned above, and a sixth controllable valve 55 between the first fluid return conduit 23 and the cylinder 39 proximate to the second radial position mentioned above.

As schematically indicated in fig. 1, the second, third and fourth controllable valves 47, 49, 51 are radially and angularly distributed.

For controlling the operation of the controllable valves 45, 47, 49, 51, 53 to 55, the device 1 additionally comprises an angle sensor 57 and a control unit 59, the control unit 59 being connected to the angle sensor 57 and to the controllable valves 45, 47, 49, 51, 53 to 55 for providing control signals to the controllable valves 45, 47, 49, 51, 53 to 55.

In the first operating mode mentioned above, the electric motor 65 rotates the first conduit 3 and, consequently, the fluid return means 19, about the rotation axis 5 in a first angular direction 67, as schematically indicated in fig. 1.

When the electric motor 65 rotates the fluid conduit 3 in the first angular direction 67 about the rotation axis 5, the batch of water and air is transported from the first inlet 7 and the second inlets 9a to 9b towards the common outlet 11, where the batch of pressurized air and pressurized water is output.

After being output through the common outlet 11, the pressurized water and the pressurized air are separated in the fluid separator 41. Pressurized air may be drawn through air nozzle 69 while pressurized water is allowed to enter first fluid return conduit 23 through first controllable valve 45. Depending on the angular position of the cylinder 39 of the piston device 21, the fifth controllable valve 53 or the sixth controllable valve 55 will be controlled to allow pressurized water to enter the cylinder 39 to push the piston 37 towards the rotation axis 5 or away from the rotation axis 5. In the angular position of the cylinder, schematically illustrated in fig. 1, the piston 37 is maximally inserted in the cylinder 39, which means that the fifth controllable valve 53 is controlled to be closed and the sixth controllable valve 55 is controlled to be open to allow pressurized water to push the piston 37 towards the rotation axis 5 relative to the cylinder 39. The radially directed force acting on the piston 37 is converted into a torque in a first angular direction 67. Thus, the piston device 21 assists the motor 65 in rotating the fluid conduit 3 in the first angular direction 67 about the rotational axis 5.

Water in the cylinder 39 on the other side of the piston plate (in this case the side facing the axis of rotation 5) is pushed into the second inlet 9b via the third fluid return conduit 31. As the work done by the piston means 21 acts on the fluid conduit 3 to rotate the fluid conduit 3, the water pushed into the second inlet 9b has been depressurised by the cylinder compared to the water entering the cylinder via the first fluid return conduit 23.

The return of the pressurized second fluid (water) (having the highest pressure) from the second outlet (common outlet 11) was described above. It is also advantageous to return pressurized water with a different and lower pressure from the further outlet along the fluid conduit 3. Thus, the third outlet 13, the fourth outlet 15 and the fifth outlet 17 are also fluidly connected to the first fluid return conduit 23, and pressurized water is allowed to pass through these outlets from the fluid conduit 3 by controlling their respective controllable valves.

As can be readily appreciated, each turn/turn of the fluid conduit 3 is partially filled with water and partially filled with air. Specifically, the lower portion of each turn/turn is filled with water. When the device 1 is in operation, the water in each revolution is deflected due to the increase in pressure in the fluid conduit 3. This is described in detail in WO 2016/080902.

For the selective return of pressurized water, the control unit 59 is configured to control the different controllable valves to open one or several flow paths between the fluid conduit 3 and the cylinder 39, taking into account the angular position of each controllable valve.

Although not shown in fig. 1, it may be beneficial to provide the device with a temperature control device. In the device 1 in fig. 1, such temperature control means may be provided, for example, in the form of a cooler arranged and configured to cool water. This can be particularly advantageous because the device 1 has a closed circuit for water and does not rely on an external water reservoir. The temperature control device may, for example, use external ambient air to cool the continuous compression process.

In examples where the device is used to compress and expand, for example, air for energy storage, it may be advantageous to: cooling air and/or water in a compression mode, thereby converting rotation into fluid; and the air/water is heated in the expansion mode, thereby converting the fluid flow into rotation. The cooling or heating source may for example be derived from the temperature difference between surface water and bottom water in oceans and lakes or other naturally occurring temperature differences such as the temperature difference between underground geothermal and air temperatures. The cooling or heating source may also come from a solar collector panel or from burning biofuel.

An exemplary and somewhat simplified control sequence of the controllable valves in the device 1 in fig. 1 will now be described with reference to fig. 2. It should be noted that the device 1 may comprise additional valves, which may be, for example, mechanical, pneumatic or hydraulic valves, and which need not necessarily be controlled in a sequence as described herein. For example, one or several valves in fig. 1, such as valve 45, may be controlled to open several times during one revolution of the coiled first conduit.

The x-axis in fig. 2 indicates the angle of rotation phi of the fluid conduit 3 (and the different outlets, controllable valves and piston arrangements) from 0 deg. to 360 deg., and the y-axis schematically indicates the control signals for the different controllable valves. The angular position indicated in fig. 1, in which the piston 37 is maximally inserted in the cylinder 39, is represented by a starting angle of 0 °.

From 0 ° to 90 °, the control unit 59 controls the fourth controllable valve 51 to open to allow pressurized water to flow from the fluid conduit 3 through the fourth controllable valve 51 to the first fluid return conduit 23. As indicated in fig. 2, as the control unit 59 controls the sixth controllable valve 55 to open between 0 ° and 180 °, pressurized water leaving the fluid conduit 3 through the fourth controllable valve 51 enters the cylinder 39 through the sixth controllable valve 55 to push the piston 37 radially inwards in the cylinder 39.

From 90 ° to 180 °, the control unit 59 controls the third controllable valve 49 to open to allow pressurized water having a higher pressure to flow from the fluid conduit 3, through the third controllable valve 49, to the first fluid return conduit 23, through the sixth controllable valve 55, into the cylinder 39 to continue pushing the piston 37 radially inwards in the cylinder 39.

From 180 ° to 270 °, the control unit 59 controls the second controllable valve 47 to open to allow pressurized water having a higher pressure to flow from the fluid conduit 3 through the second controllable valve 47 to the first fluid return conduit 23. As indicated in fig. 2, as the control unit 59 controls the fifth controllable valve 53 to be open between 180 ° and 360 °, pressurized water leaving the fluid conduit 3 through the second controllable valve 47 enters the cylinder 39 through the fifth controllable valve 53 to push the piston 37 radially outwards in the cylinder 39.

From 270 ° to 360 °, the control unit 59 controls the first controllable valve 45 to open to allow pressurized water with a higher pressure to flow from the fluid conduit 3 via the fluid separator 41 through the first controllable valve 45 to the first fluid return conduit 23, through the fifth controllable valve 53 into the cylinder 39 to continue pushing the piston 37 radially outward in the cylinder 39.

It should be noted that the fluid return means 19 in the device 1 in fig. 1 may comprise additional piston means 21 and/or other configurations of pressure reducing means. The plurality of piston means may for example enable a smoother flow of the returned depressurized second fluid. One example of an alternative way of depressurizing the pressurized second fluid will be described below with reference to fig. 3.

Referring to fig. 3, a so-called displacement pump 71 may be used as an alternative to the piston arrangement 21 in fig. 1. As schematically indicated in fig. 3, a displacement pump 71, well known per se, comprises a housing 73, a rotor 75, an inlet port 77 and an outlet port 79. As can be observed in fig. 3, the rotor 75 is eccentrically arranged in the housing 73 and is provided with spring-loaded blades 81a to 81 d.

In place of the piston device 21 of fig. 1, the housing 73 may be allowed to rotate with the fluid conduit 3 (like the cylinder 39 of fig. 1), and the rotor 75 may be fixed to a non-rotating part of the apparatus 1 of fig. 1. The first fluid return conduit 23 may be connected to the inlet port 77 and the second fluid return conduit 29 may be connected to the outlet port 79 of the displacement pump 71.

Fig. 4A to 4B schematically illustrate an apparatus in the form of a standalone compressor/air motor 100, according to a second example embodiment of the invention. The compressor/air motor 100 is a device that can operate in two modes of operation: a first mode in which rotation is converted to fluid (air) flow; and a second mode in which the flow of pressurized fluid (air) is converted into rotation.

The above-mentioned first operation mode will be described in detail herein. The second operation mode mentioned above relates only to running the device "backwards" compared to the first operation mode. This means that certain fluid ports that are "inlets" in the first mode will be "outlets" in the second mode, and certain fluid ports that are "outlets" in the first mode will be "inlets" in the second mode. This also means that the electric motor in the first operation mode is a generator in the second operation mode. In addition to operating the device "backwards," various other minor adjustments may also be needed and/or beneficial. However, such minor adjustments would be well within the ability of one of ordinary skill in the art in view of the description provided herein.

The main difference between the apparatus 100 according to the second embodiment shown in fig. 4A to 4B and the apparatus 1 according to the first embodiment shown in fig. 1 lies in the configuration of the fluid return means 119.

As schematically shown in fig. 4A-4B, the fluid conduit 3 has a first outlet and a second outlet in the form of a common outlet 111 (the common outlet 111 corresponds to the common outlet 11 in fig. 1, more easily seen in fig. 1) for outputting a pressurized first fluid (such as air) and a pressurized second fluid (such as water). Hereinafter, the terms "air" and "water" will be used. However, it should be understood that the first and second fluids need not be air and water as further explained above.

In addition to the first inlet and the second inlet, here provided as a common inlet 107, the fluid conduit 3 in the device 100 in fig. 4A-4B has: a third outlet 113 for outputting water, a fourth outlet 115 for outputting water and a fifth outlet 117 for outputting water. As schematically indicated in fig. 4A-4B, the third outlet 113 is arranged along the fluid conduit 3 between the common outlet 111 and the common inlet 107, the fourth outlet 115 is arranged between the third outlet 113 and the common inlet 107, and the fifth outlet 117 is arranged between the fourth outlet 115 and the common inlet 107.

The fluid conduit 3 in the apparatus 100 in fig. 4A-4B also has a third inlet 121, a fourth inlet 123, a fifth inlet 125 and a sixth inlet 127 for receiving air into the fluid conduit 3. The third inlet 121 is arranged along the fluid conduit 3 between the common outlet 111 and the third outlet 113, the fourth inlet 123 is arranged between the third inlet 121 and the common inlet 107, the fifth inlet 125 is arranged between the fourth inlet 123 and the common inlet 107, and the sixth inlet 127 is arranged between the fifth inlet 125 and the common inlet 107.

As indicated in fig. 4A-4B, the apparatus 100 further comprises a first container 129, a second container 131, a third container 133, and a fourth container 135. Each of these containers is used to return pressurized water while depressurizing the water. The energy brought by the pressurized water is used to pressurize the air and this pressurized air is injected at suitable locations along the fluid conduit 3 in order to restore the desired ratio between alternating portions of (compressible) air and portions of (incompressible) water along the fluid conduit 3. When pressurized water is used to pressurize and inject air as described above, the depressurized water is provided to the common inlet 107.

The function of the pressure reduction means 119 in the second embodiment of the apparatus 100 in fig. 4A to 4B will be described for one stage involving the first container 129. The functions of each of the other stages are the same or similar, and thus detailed descriptions of the functions of each of the other stages will be omitted.

The first vessel 129 has a first vessel inlet 137, a first vessel outlet 139, a second vessel inlet 141, and a second vessel outlet 143. As schematically indicated in fig. 4A-4B, the first container inlet 137 is connected to the common outlet 111, the first container outlet 139 is connected to the third inlet 121, the second container outlet 143 is connected to the common inlet 107, and the second container inlet 141 is connected to the atmosphere via a check valve. The first container outlet 139 may also be provided with a check valve and the first container inlet 137 and the second container outlet 143 may be provided with controllable valves. Clearly, the selection of and control of the flow control devices for controlling flow into and out of the vessel may depend on the particular application, and it will be straightforward for a person of ordinary skill in the art to select and establish a control sequence for the flow control devices, if applicable, based on the description provided herein.

In operation, the first container inlet 137 is opened during a suitable period of time to receive pressurized water from the common outlet 111 into the first container 129. The pressurized water (indicated by solid arrows in fig. 4A) entering the first container 129 is used to pressurize the air and inject the pressurized air (indicated by unfilled arrows in fig. 4A) into the fluid conduit 3 through the third inlet 121 of the fluid conduit. The suitable time period may be selected as the time when water flows out of the common outlet 111 and pressurized air is added to the existing air fraction in the fluid conduit 3 at the third inlet 121. Once the first container 129 has been filled with water, the first container outlet 139 is closed and the second container outlet 143 is opened to allow water in the first container 129 to be drawn into the common inlet 107 of the fluid conduit 3. The water drawn from the first container 129 is replaced by air entering the first container 129 through the second container inlet 141. When all water has been removed from the first container 129 and before the time when the first container 129 again receives pressurized water, air may be drawn into the common inlet 107 of the fluid conduit 3 via the second container inlet 141.

Fig. 4A schematically indicates the first part of the sequence in which pressurized water enters the container and air is pressurized and injected into the fluid conduit. Figure 4B schematically shows the second part of the sequence in which reduced pressure water is drawn into the common inlet 107 of the fluid conduit and air at atmospheric pressure enters the container.

The person skilled in the art realizes that the present invention by no means is limited to the preferred embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims. For example, the fluid return means 19 may comprise a flow and/or pressure stabilising reservoir. The fluid return device 19 may be equipped with several check valves in sequence for better flow control. Several parallel fluid return means 19 may also be used, or several outlets/inlets may be connected to the same vessel. A fluid return device may also have several parallel piston devices, which may be connected to different outlets, for example. This may enable operation with fewer controllable flow control devices, or no controllable flow control devices at all.

In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims shall not be construed as limiting the scope.