Hydraulic prime mover having an impeller with adjustable blades

Abstract

Proposed is a hydraulic prime mover comprising a rod (7) that is movable in an axial direction, at least one cantilever arm (8), at least one gap (9), and at least one radar system (10), wherein: the rod is arranged in a cavity of the shaft (4); the at least one cantilever arm is fastened to the rod; the at least one cantilever arm protrudes through the at least one gap, which is arranged in the shaft, so as to project beyond the shaft perpendicularly with respect to the axis of rotation; the rod is connected to the mechanism for adjusting the blades (1) such that an adjustment of the blades leads to an axial movement of the rod; the at least one radar system is designed and arranged to be capable of detecting a first distance to a part of the shaft and a second distance to the at least one cantilever arm and transmitting these to the control device (12).

Description

[0001] Hydropower machine with a runner with adjustable blades

[0002] The invention relates to a hydropower machine with a rotor with adjustable blades. Such rotors are also known as Kaplan rotors. The invention particularly relates to the control and vibration monitoring of such a hydropower machine.

[0003] Such hydropower machines are known from the prior art. For example, DE 329 528 B discloses such a hydropower machine. A gear located in the hub of the impeller serves to adjust the blade inclination. The gear is operated via a push rod, which is driven by a power piston located above the electric motor. Above the power piston, a push rod is extended to form a feedback rod. With the help of this feedback rod, the return movement is diverted to the control components of the controller. In modern hydropower machines of this type, the power piston is also located in the hub of the impeller, and control is achieved via a control device, which is usually referred to as a digital controller. However, feedback of the blade position is still required to control the blade inclination.Complex mechanical structures are usually required to transmit this information to the control device.

[0004] The object of the invention is to provide a hydropower machine designed so that feedback information about the blade position can be transmitted to the control device with minimal mechanical effort. The solution according to the invention also enables vibration monitoring of the hydropower machine's shaft.

[0005] The object is achieved according to the invention by an embodiment according to the independent claims. Further advantageous embodiments of the present invention can be found in the subclaims. The invention is explained below with reference to figures. The figures show in detail:

[0006] Fig.1 Generic hydroelectric machine;

[0007] Fig.2 Detail of a hydropower machine according to the invention in a first embodiment;

[0008] Fig.3 Section perpendicular to the axis of rotation of the embodiment according to Fig. 2;

[0009] Fig. 4: Section perpendicular to the rotation axis of another embodiment; Fig. 5: Section perpendicular to the rotation axis of another embodiment; Fig. 6: Embodiment according to Fig. 2 with a rotating radar system; Fig. 7: Embodiment according to Fig. 2 with a stationary radar system;

[0010] Fig.8 Embodiment according to Fig. 5 with stationary and redundant radar system;

[0011] Figure 1 shows a schematic representation of a hydropower machine of this type. The hydropower machine comprises an impeller with a plurality of adjustable blades, only one of which is shown and designated 1. The blades 1 are arranged on a hub, designated 2. Within the hub 2, the mechanism for adjusting the blades is arranged, which is only indicated in Figure 2. The impeller is connected to the hub 2 with a shaft, which in turn is connected to the rotor of an electrical machine. The shaft is designated 4 and the rotor 5. The shaft 4 can be made from one piece. However, it usually consists of two partial shafts, designated 4.1 and 4.2 in Figure 1. Partial shaft 4.1 is usually referred to as the turbine shaft or impeller shaft, and partial shaft 4.2 as the generator shaft. The impeller rotates in a tubular section, which is usually referred to as the impeller ring.In Figure 1, the impeller ring is designated 3. The rotor 5 rotates in a stator, which is designated 6. The axis of rotation is indicated in the figure by the dashed line. Furthermore, the hydropower machine comprises a control device, designated 12. The control device serves to regulate the blade inclination and can also be used to monitor the hydropower machine. These two functions can also be performed in separate units. For the purposes of this document, the control device 12 is considered a higher-level unit, which may optionally comprise two or more separate or interconnected sub-units. The impeller ring 3, the stator 6 and the control device 12 belong to the stationary system of the hydropower machine, while all other components shown belong to the rotating system.

[0012] Figure 2 shows a detail of a hydropower plant according to the invention. This is the area where the two partial shafts 4.1 and 4.2 are connected to each other. At this point, the two partial shafts form a flange. In the hollow interior of the impeller shaft 4.1, there is an axially movable rod, designated 7. The rod 7 is connected to the mechanism for adjusting the blades (not shown in Figure 2) in such a way that adjusting the blades 1 leads to an axial movement of the rod 7. In the embodiment shown, this connection is realized by the thinner rod leading downwards into the hub. When the blades are adjusted, the rod 7 moves up or down, depending on the direction in which the blades are adjusted. This is indicated in Figure 2 by the double arrow. A cantilever arm, designated 8, is attached to the rod 7.The extension arm 8 projects from the interior of the impeller shaft 4.1 through a gap in the impeller shaft 4.1 to such an extent that it protrudes beyond the flange in a direction perpendicular to the rotation axis. The gap is designated 9. The gap 9 is designed so that the extension arm 8 can follow the movement of the rod 7. The rod 7 and the gap 9 could also be arranged in the generator shaft 4.2.

[0013] A hydropower plant according to the invention comprises at least one radar system, which is indicated in Figure 2 by the rectangle designated 10. The radar system 10 is arranged such that it can detect a part of the shaft 4 and the extension arm 8, i.e., it can detect a distance to a part of the shaft 4 and a distance to the extension arm 8. The dashed lines indicate the field of view of the radar system. In the embodiment shown, the part of the shaft 4 detected by the radar system is the top side of the flange between the two partial shafts 4.1 and 4.2. The radar system 10 is connected to the control device 12. The radar system is designed such that it can transmit the detected distances to the control device. The difference between the distances represents the feedback information transmitted to the control device 12.

[0014] The radar system 10 can be configured, for example, as a CW or FMCW radar system. A CW or FMCW radar system typically comprises a transceiver with a transmitting and receiving antenna, and a control device. The transmitting and receiving antennas can be configured separately as two individual antennas or integrally as a single antenna that can perform both the transmitting and receiving functions. The control device typically comprises a microprocessor that controls the transceiver, processes the received signal, and ensures the connection to a computer that is also part of the radar system.

[0015] It should be noted that the arrangement of rod 7, extension arm 8, gap 9, and radar system 10 shown in Figure 2 does not have to be arranged on the flange between the partial shafts 4.1 and 4.2. The aforementioned elements could also be arranged on another part of the shaft 4. It is only important that the shaft 4 is designed at the relevant location such that a defined distance results between the part of the shaft 4 detected by the radar system 10 and the extension arm 8. For this purpose, the shaft can have a shoulder or a projection. It could also be a recess in the shaft 4. Thus, the arrangement according to the invention can also be implemented with a one-piece shaft. On the flange of a two-piece shaft between the partial shafts 4.1 and 4.2, this requirement is met without any additional effort, since the flange represents a suitable shoulder. In addition, a connection of the rod 7 to the mechanism for adjusting the blades must be possible. This meansthe shaft must be hollow from the point in question to the hub.

[0016] Figure 3 shows a section perpendicular to the rotation axis through the embodiment shown in Figure 2 in the region of the extension arm 8. The extension arm 8 optionally forms a platform at the outer end, which improves the detection of the extension arm 8 by the radar system 10. Figure 4 shows the same view as Figure 3 of a further embodiment of the present invention. The illustrated embodiment differs from the embodiment shown in Figure 3 in that it comprises two extension arms 8. For this purpose, the shaft 4 must have a further gap 9.

[0017] Figure 5 shows the same view as Figure 3 of another embodiment of the present invention. The illustrated embodiment differs from the embodiments shown in Figures 3 and 4 in that it comprises three extension arms 8 and three slots 9, and that a ring, designated 11, is attached to the outer end of the extension arms 8. In order not to unnecessarily complicate the wording of the claims, the ring 11 is considered part of the extension arms 8 in this document.

[0018] The advantages of the embodiments shown in Figures 4 and 5 are shown in connection with Figures 6 and 7.

[0019] Figure 6 shows the embodiment according to Figure 2. The difference from Figure 2 is that Figure 6 shows that the radar system 10 is attached to the shaft 4. This means that in the embodiment shown in Figure 6, the radar system 10 is part of the rotating system and rotates with the shaft 4. This allows the radar system 10 to continuously detect distances.

[0020] Figure 7 shows an embodiment in which the radar system 10 is part of the stationary system. In this embodiment, the extension arm 8 or arms 8 move periodically through the field of view of the radar system 10 during operation of the hydropower plant. As a result, the distances are periodically recorded by the radar system.

[0021] It is clear that continuous distance detection facilitates signal evaluation and control. This advantage is particularly evident when the radar system 10 rotates. For this purpose, the radar system 10 is positioned above or, just as easily, below the relevant extension arm 8. When combined with the embodiment shown in Figure 4, two radar systems 10 are used, so that the distance detection and thus the transmission of feedback information is redundant. The redundancy can be increased as desired by multiplying the extension arms 8 and radar systems 10.

[0022] If the radar system 10 is part of the stationary system, the embodiment shown in Figure 5 enables a continuous distance signal. This combination is illustrated in Figure 8. The illustrated embodiment comprises two radar systems 10, so that the distance is detected redundantly. Redundancy is to be considered optional. Two radar systems 10 as shown in Figure 5 also allow for the elimination of any wobble of the ring 11.

[0023] As mentioned above, the radar system(s) can be configured as a CW or FMCW radar system. CW radar systems and FMCW radar systems enable the implementation of the methods according to the invention, which are described below.

[0024] The method according to the invention for controlling a hydropower machine comprises the following steps:

[0025] - Measuring a distance to the detected part of the shaft 4

[0026] - Measuring a distance to a boom 8

[0027] - Comparison of the difference between the measured distances with a target value

[0028] - If there is a significant difference between the difference and the setpoint: Adjust the blades to adjust the difference to the setpoint

[0029] The method according to the invention for vibration monitoring of a hydropower machine comprises the following steps:

[0030] - Measuring a vibration of the shaft 4 and / or a cantilever arm 8 using the radar system 10 - Comparing the measured vibration values ​​with predefined limit values

[0031] If the described inventive arrangement detects shaft vibration behavior that exceeds a predefined level, it can generate a warning message and / or cause the hydropower machine to shut down. The predefined limit values ​​can, for example, be vibration amplitude values ​​in specific frequency ranges. It is clear that the predefined limit values ​​for shaft 4 and a cantilever arm 8 can be different.

[0032] Finally, it should be mentioned that signal transmission between a co-rotating radar system can be wireless. The radar system can be powered via slip rings or a battery. It is also conceivable to generate the required energy through induction processes.

[0033] List of reference symbols

[0034] 1 shovel

[0035] 2 Hub 3 Impeller ring

[0036] 4th wave

[0037] 4.1 Impeller shaft

[0038] 4.2 Generator shaft

[0039] 5 Rotor 6 Stator

[0040] 7 bars

[0041] 8 Extension arm

[0042] 9 gap

[0043] 10 Radar system 11 Ring

[0044] 12 Control device

Claims

Patent claims 1. A hydropower machine comprising a rotor rotatable about a rotational axis and having a plurality of adjustable blades (1) arranged on a hub (2), and wherein the hydropower machine comprises a shaft (4) and a mechanism for adjusting the blades (1), and wherein the shaft (4) is connected to the hub (2), and wherein the mechanism for adjusting the blades (1) is arranged in the hub (2), and wherein the hydropower machine comprises a control device (12), characterized in that the hydropower machine comprises an axially movable rod (7), at least one extension arm (8), at least one gap (9), and at least one radar system (10), and wherein the rod (7) is arranged in a cavity of the shaft (4), and wherein the at least one extension arm (8) is fastened to the rod (7), and wherein the at least one extension arm (8) thus projects through the at least one gap (9) arranged in the shaft (4).that it projects beyond the shaft (4) in a direction perpendicular to the axis of rotation, and wherein the rod (7) is connected to the mechanism for adjusting the blades (1) in such a way that adjusting the blades (1) leads to an axial movement of the rod (7), and wherein the at least one radar system (10) is designed and arranged in such a way that it can detect a first distance to a part of the shaft (4) and a second distance to the at least one extension arm (8) and transmit them to the control device (12).

2. Hydropower machine according to claim 1, wherein the hydropower machine comprises a stationary system, and wherein the at least one radar system (10) is part of the stationary system.

3. Hydropower machine according to claim 1, wherein the hydropower machine comprises a rotating system, and wherein the at least one radar system (10) is part of the rotating system. Hydropower machine according to one of the preceding claims, wherein the shaft (4) comprises two partial shafts (4.1, 4.2), and wherein the partial shafts (4.1, 4.2) are connected to a flange, and wherein the at least one gap (9) is arranged in the flange, and wherein the part of the shaft (4) from which the distance from the at least one according to one of the claims 1 to 7 radar system (10) is a part of the flange. Hydropower machine according to one of the preceding claims, wherein the hydropower machine comprises three extension arms (8) and a ring (11), and wherein the extension arms (8) are connected to the ring (11) at their outer end. Hydropower machine according to one of claims 1 to 5, wherein the at least one radar system (10) is designed as a CW radar system. Hydropower machine according to one of claims 1 to 5, wherein the at least one radar system (10) is designed as an FMCW radar system. A method for controlling a hydropower machine according to one of claims 1 to 7, wherein the method comprises the following steps: - measuring a first distance to a part of the shaft (4); - measuring a second distance to the at least one extension arm (8); - Comparison of the difference between the measured distances with a target value; - If a significant difference arises between the difference and the target value: adjusting the blades (1) to adjust the difference to the target value. A method for monitoring vibrations in a hydropower machine according to any one of claims 1 to 7, comprising the following steps: - measuring a vibration of the shaft (4) and / or a cantilever arm (8) using the radar system (10); - Comparison of the measured vibration values ​​with predefined limit values.

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