Free flow turbine plant

Abstract

The invention relates to a free-flow turbine system, in particular a current buoy, for generating electrical energy in free-flowing waters with slow-running, axially driven turbine runners (3), and with a flow-through housing (1) surrounding the turbine runners (3), wherein the flow-through housing (1) has at least one bow-side inlet opening (2) for the water to enter and wherein a screen (20) is arranged upstream of the inlet opening (2), wherein the screen (20) has deflecting bars (7, 7a-7c) which extend from a support (6) upstream of the inlet opening (2) in the direction of the inlet opening (2), characterized in that the deflecting bars (7, 7a-7c) of the screen (20) extend downstream of the inlet opening (2) and outside the inlet opening (2) and are spaced apart from the flow-through housing (1).

Description

[0001] The invention relates to a free-flow turbine system, in particular a current buoy, for generating electrical energy in free-flowing waters with slow-running, axially driven turbine runners, and with a flow-through housing surrounding the turbine runners, wherein the flow-through housing has at least one bow-side inlet opening for the water to enter and wherein a screen is arranged upstream of the inlet opening, wherein the screen has deflecting bars that extend from a support upstream of the inlet opening in the direction of the inlet opening.

[0002] EP 1 747 373 A1 discloses a current buoy comprising a rake with tensioned ropes acting as a deflector. These ropes are stretched between the support and the flow housing, thus directing fish, swimmers, and objects away from the inlet opening. This prevents people, larger animals, or larger objects such as debris, twigs, or branches from damaging the turbine impellers, and also prevents swimmers from entering the turbine.

[0003] However, this design inevitably leads to clogging. This begins with small twigs, algae, and even plastic accumulating at the attachment point of the deflector on the flow-through housing, and gradually incorporates larger objects. This quickly results in a reduction in the buoy's performance and necessitates frequent maintenance to clear these blockages. Consequently, the current yield decreases, and operating costs increase, both of which reduce efficiency.

[0004] EP 4 123 158 A1 discloses a free-flow turbine plant as described above. The blockage described above also occurs there.

[0005] The object of the invention is to provide a free-flow turbine system of the type mentioned above that has a higher efficiency.

[0006] This problem is solved according to the invention by the deflecting bars of the screen extending downstream beyond the inlet opening and outside the inlet opening, and being spaced apart from the flow housing.

[0007] By guiding the deflection rods outside and around the inlet opening, debris is directed along the deflection rods past the inlet opening and along the outside of the flow casing. The spacing between the rods and the flow casing prevents the debris from accumulating at the ends of the deflection rods. This spacing ensures that the downstream ends of the deflection rods are freestanding, preventing any build-up. The deflected debris exits the downstream end of the deflection rods and drifts past the free-flow turbine system.

[0008] The screen is positioned in front of the inlet opening and prevents objects or larger living beings from flowing into the inlet opening to protect the system and the living beings.

[0009] Preferably, the free-flow turbine system is anchored to the bottom of the body of water by means of a traction device.

[0010] As a rule, the free-flow turbine system has at least one generator that is rotatably connected to the turbine runner.

[0011] Preferably, at least one, and preferably all, deflection rods are rigid and / or designed as a rod or tube. Rigid in this context means that the deflection rods are so stiff that they remain essentially spaced from the flow-through housing throughout, despite the forces exerted on them by water currents during intended use and by any floating objects or organisms. It is quite possible that, in the event of a collision with heavy debris or during a particularly strong turbulent flow, they may bend elastically for a short time, temporarily coming into contact with the flow-through housing.

[0012] By using a rod or tube, a simple and cost-effective design is achieved that is sufficiently rigid.

[0013] Preferably, the deflection rods are connected to the bracket at their front end regions.

[0014] It is further advantageous if at least one, preferably all, deflection rods, preferably exclusively, extend along a longitudinal axis of the free-flow turbine system from the support essentially in the direction of flow, i.e., downstream. The direction of flow refers to the main flow direction of the water when the free-flow turbine system is operating as intended and generating electricity through the flow. This prevents debris from accumulating between a support and an upstream portion of the deflection rods.

[0015] Furthermore, it can be advantageous if the deflection rods are attached exclusively to the bracket. This ensures that no further connections to the deflection rods downstream of the bracket could promote clogging.

[0016] Preferably, at least one deflector rod can be brought into contact with the flow casing by elastic deformation. This means that this is possible under the operating conditions of the free-flow turbine system, for example, at temperatures between 0°C and 35°C. Alternatively, the distance between at least one deflector rod and the flow casing can be selected such that the contact of the flow casing by the deflector rod lies within the elastic deformation range of the deflector rod.

[0017] These measures ensure that, under particularly heavy loads, such as when a large piece of wood or a tree trunk rams the deflector rod, it can brace itself against the flow-through housing and the force can be dissipated via the housing. This prevents the deflector rod from breaking. After the load is removed, i.e., once the tree trunk has floated past, the deflector rod moves away from the flow-through housing again, thus ensuring that no blockage occurs in the area of ​​contact.

[0018] It is also advantageous if the deflection rods are at least 3 cm and / or a maximum of 15 cm away from the flow-through housing at their closest point. This creates enough space to prevent blockages and provides good support under particularly heavy loads on the deflection rods.

[0019] In a preferred embodiment, at least one deflection rod is positioned at an angle to a longitudinal axis of the free-flow turbine system, and this angle is adjustable via an adjustment device. This allows the distance between the deflection rod and the flow casing to be precisely adjusted as needed. If the longitudinal axis and the deflection rods lie in different planes, it is essential that the angle relative to a projection—as a parallel displacement—of the longitudinal axis onto the plane of the deflection rod is adjustable. It can also be provided that the angle of several deflection rods can be adjusted via an adjustment device.

[0020] In this respect, it is particularly advantageous if the adjustment device is located in the area where the deflection rod connects to the bracket. This prevents a multitude of connections between the deflection rod and the other parts.

[0021] Furthermore, the adjusting device may include a guide element that is rotationally fixed to the deflection rod and is preferably pivotably connected to a base, which is rotationally fixed to the bracket, via a slotted bolt connection. For example, the deflection rod may be rotatably or pivotably connected to the bracket, with the guide element directing the deflection rod in its rotation or pivoting motion.

[0022] It is also advantageous if the adjusting device has at least one locking mechanism for fixing an angle. This can be achieved, for example, by a slotted bolt connection – such as when a screw-in bolt is used – or by an additional locking device.

[0023] Preferably, at least one base and at least one guide element comprise plates which are arranged next to each other and preferably abut each other over a flat surface. This enables good connection and force transmission. It can be provided that one base is connected to several guide elements, as for example in the second embodiment of the Figuren 3 - 5 shown.

[0024] Furthermore, it may be provided that at least one deflector rod in the area of ​​the flow-through housing is adapted to the outer contour of the flow-through housing. This can lead to improved flow characteristics of the system and prevent or reduce unwanted flows.

[0025] To reduce or prevent damage to the components, at least one deflector rod may be provided with a sheath, preferably made of plastic or rubber, at least in the area of ​​the flow housing. The sheath is preferably soft and / or elastic and / or resilient.

[0026] The invention will subsequently be described with reference to non-limiting embodiments according to the invention shown in the figures. These show: Fig. 1 a section of a perspective side view of a first embodiment according to the invention; Fig. 2 a part of a schematic section through the first embodiment; Fig. 3 a section through a holder of a second embodiment according to the invention; Fig. 4 the section from Fig. 3 with an additional first deflection rod shown at a first angle; Fig. 5 shows the section from Fig. 3 with an additional second deflection rod shown at a second angle.

[0027] The first embodiment of a free-flow turbine plant shown in Figs. 1 and 2 The device is designed as a current buoy and features a flow-through housing 1, which is tubular and has a substantially annular to oval cross-section. It has an inlet opening 2 at one upstream end and an outlet opening at the opposite, downstream end (not shown in the figure). In its intended use, water flows along a flow direction S and through the flow-through housing 1, i.e., from the inlet opening 2 to the outlet opening.

[0028] Turbine impellers 3 are arranged in the flow casing 1 and rotate due to the flow, generating electricity with the aid of a generator 4 connected to them. Guide vanes 5 are arranged upstream of the turbine impellers 3, extending radially outwards from a longitudinal axis L of the free-flow turbine system towards the flow casing 1.

[0029] Upstream of the flow-through housing 1, a support 6 is provided, which is rigidly connected to the flow-through housing 1. Preferably, as shown in this embodiment, it is connected to the flow-through housing 1 on a top and a bottom surface, as well as centrally. Along a main arm 10 of the support 6, several deflecting bars 7 of a screen 20 are attached to both sides of the main arm 10, all of which extend along the longitudinal axis L from their attachment point on the support exclusively downstream, i.e., in the direction of the flow-through housing 1.

[0030] Preferably, the deflection rods 7, as shown in the embodiment, are arranged at least partially, preferably in pairs, at different heights in the cross-section of the system.

[0031] The deflection rods 7 all extend radially outwards and lead from the bracket 6 past the inlet opening 2, remaining spaced away from the flow housing 1 and thus not touching it. A gap 12 is provided between the deflection rods 7 and the flow housing 1.

[0032] At the downstream ends of the deflection rods 7, they are encased with a spring-like covering 7d.

[0033] In the first embodiment, the bracket 6 has several retaining plates 11, into each of which two deflection rods 7 are inserted. These retaining plates 11 determine the angle 8 between the longitudinal axis L and the respective deflection rod 7.

[0034] In Fig. 2 Only schematically selected components of the first embodiment are shown to illustrate the guidance of the deflection rods 7. The retaining plates 11, for example, are not shown for clarity. Visible here are an uppermost deflection rod 7a and a lowermost deflection rod 7b, as well as a middle deflection rod 7c. It can be seen that the middle deflection rod 7c is adapted to the contour of the flow housing 1 along its longitudinal extent and extends in a curved line from its outer surface to a distance 12.

[0035] The Figuren 3 - 5 The second embodiment shown is very similar to the first; therefore, only the most significant differences will be discussed here. Components with the same function have the same reference numeral. Explanations regarding the first embodiment also apply here, where applicable.

[0036] In Fig. 3 A section through a support 6 at the level of two deflection rods 7 is shown, although the deflection rod 7 is not shown. It is visible that the main arm 10 has a flow cross-section adapted to the main flow direction S.

[0037] An adjustment device 9 is provided on the bracket 6, which has a base 13 in the form of a plate that is non-rotatably connected to the bracket 6. In this embodiment, it is welded to the bracket 6. The adjustment device 9 further has pivot or swivel connections 14 for each deflection rod 7, which are arranged at the upstream end of the adjustment device 9 and directly on the main arm 10. These define axes of rotation D for the deflection rods 7. The base 13 also has two bolts 15 spaced apart from each pivot or swivel connection 14.

[0038] In Fig. 4 A deflection rod 7 is also shown, which is rotationally fixed to a guide element 17 in the form of a guide plate, preferably by welding. This guide element 17 has a curved elongated hole 16 into which the bolts 15 can engage. This necessitates an elongated hole-bolt connection, although it is also possible for the bolt 15 to be arranged on the guide element 17 and the elongated hole 16 on the base 13. In this way, the deflection rod 7 can be pivoted about the axis of rotation D, while the bolts 15 move along the elongated hole 16. The bolts 15 limit the movement between a maximum angle 8a, shown in Fig. 4 , and a minimum angle 8b, shown in Fig. 5 , of the angle 8 between longitudinal axis L and deflection rod 7. The bolts 15 are designed as screws which can be tightened after the angle has been set, thus preventing further, unintentional pivoting.

[0039] In Fig. 5 Another deflection rod 7 is shown, which stands at a minimal angle 8b to the longitudinal axis L.

[0040] The downstream side of the guide element 17 is shaped along the contour of the elongated hole 16. Likewise, the downstream side of the base 13 is adapted to this contour of the two guide elements 7.

Claims

1. Free-flow turbine system, in particular a power buoy, for generating electrical energy in free-flowing waters with slow-running, axially loaded turbine runners (3), and with a flow-through housing (1) surrounding the turbine runners (3), wherein the flow-through housing (1) has at least one bow-side inlet opening (2) for the inlet of the water and wherein a rake (20) is arranged upstream of the inlet opening (2), wherein the rake (20) has deflection rods (7, 7a-7c) which extend from a holder (6) upstream of the inlet opening (2) in the direction of the inlet opening (2), characterized in that the deflection bars (7, 7a-7c) of the rake (20) extend downstream of the inlet opening (2) and outside the inlet opening (2) and are spaced from the flow-through housing (1).

2. Free-flow turbine system according to claim 1, characterized in that at least one deflection rod (7, 7a-7c) is rigid and / or designed as a rod or tube.

3. Free-flow turbine system according to claim 1 or 2, characterized in that the deflection rod (7, 7a-7c) is attached exclusively to the bracket (6).

4. Free-flow turbine system according to one of claims 1 to 3, characterized in that at least one deflection rod (7, 7a-7c) can be brought into contact with the flow-through housing (1) by elastic deformation.

5. Free-flow turbine system according to one of claims 1 to 4, characterized in that the deflection rods (7, 7a-7c) are at least 3 cm and / or a maximum of 15 cm away from the flow-through housing (1) at their closest point to the flow-through housing (1).

6. Free-flow turbine system according to one of claims 1 to 5, characterized in that at least one deflection rod (7, 7a-7c) is at an angle (8) to a longitudinal axis (L) of the free-flow turbine system and that the angle (8) is adjustable via an adjusting device (9).

7. Free-flow turbine system according to claim 6, characterized in thatthe adjusting device (9) is arranged in the area of the connection of the deflection rod (7, 7a-7c) to the holder (6).

8. Free-flow turbine system according to claim 6 or 7, characterized in that the adjusting device (9) has a guide element (17) which is connected in a rotationally fixed manner to the deflection rod (7, 7a-7c) and which is preferably pivotably connected via a slotted bolt connection to a base (13) which is connected in a rotationally fixed manner to the holder (6).

9. Free-flow turbine system according to one of claims 1 to 8, characterized in that at least one deflection rod (7, 7a-7c) in the region of the flow-through housing (1) is adapted to the outer contour of the flow-through housing (1).

10. Free-flow turbine system according to one of claims 1 to 9, characterized in that at least one deflection rod (7, 7a-7c) has a casing (7d) at least in the region of the flow-through housing (1), which is preferably made of plastic or rubber.

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