Hydroelectric power generation equipment

Abstract

This invention provides a technology that makes it easier to remove foreign matter that enters the water flow in hydroelectric power generation equipment. [Solution] The hydroelectric power generation device 100 has a configuration in which the rotating shaft 11 of the water turbine 10, which rotates in response to the water flow, and the rotating shaft 21 on the power generation device 20 side rotate together on the same axis. The blade 12 has a shape in which the thickness decreases towards the front end in the rotation direction C, making it easy to cut foreign objects in the water flow. In addition, a flywheel 22 is fixed to the rotating shaft 21 so as to rotate together with it at all times, and the inertial force of the flywheel 22 is used to cut foreign objects.

Description

Technical Field

[0001] The present invention relates to a hydraulic power generation device.

Background Art

[0002] Patent Documents 1 and 2 describe a technique for installing a small-scale hydraulic power generation device at a location where a small stream or a certain amount of rain can create a flow in mountainous areas or the like, and generating electricity using a small-capacity water flow.

[0003] However, in such a hydraulic power generation device, foreign substances such as natural objects like grass, trees, and stones may mix into the water flow, preventing the rotation of the waterwheel and potentially reducing the power generation amount.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] An object of the present invention is to provide a technique for easily removing foreign substances that mix into the water flow in a hydraulic power generation device.

Means for Solving the Problems

[0006] A hydraulic power generation device according to one aspect of the present disclosure includes a waterwheel in which blades receive the water flow and the first rotating shaft portion integrally rotates in a predetermined rotation direction together with the blades, a power generation device that generates electric power based on the rotation of the second rotating shaft portion that rotates in conjunction with the first rotating shaft portion, and is a hydraulic power generation device, where the first rotating shaft portion and the second rotating shaft portion are coaxial and integrally rotate with each other, A flywheel is fixed to the second rotating shaft so as to rotate together with it at all times, including during acceleration and deceleration. The blade has a front end shape in which the thickness decreases towards the front end at least at the front end in the predetermined rotation direction, and contributes to cutting foreign objects mixed in with the water flow. [Effects of the Invention]

[0007] The hydroelectric power generation device described in this disclosure makes it easier to remove foreign matter that may be mixed into the water flow. [Brief explanation of the drawing]

[0008] [Figure 1] A simplified diagram showing the configuration of a hydroelectric power generation system. [Figure 2] Cross-sectional view of the water inlet section, including the water turbine. [Figure 3] Front view of the water flow inlet. [Figure 4] A simplified cross-sectional diagram showing the configuration of the power generation unit. [Figure 5] A perspective view showing the blade. [Figure 6] A perspective view showing a modified blade. [Modes for carrying out the invention]

[0009] [1] A water turbine in which the blades receive a water flow and the first rotating shaft rotates integrally with the blades in a predetermined rotational direction, A hydroelectric power generation device comprising: a power generation device that generates electricity based on the rotation of a second rotating shaft that rotates in conjunction with the first rotating shaft; The first rotating shaft portion and the second rotating shaft portion rotate together coaxially, A flywheel is fixed to the second rotating shaft so as to rotate together with it at all times, including during acceleration and deceleration. The blade has a front end shape in which the thickness decreases towards the front end at least at the front end in the predetermined rotation direction, and contributes to cutting foreign objects mixed in the water flow. A hydroelectric power generation device.

[0010] In the hydroelectric power generation device described in [1] above, the front end of the blade is provided with a front end shape in which the thickness decreases towards the front end. This allows the front end of the blade to cut through foreign objects such as vegetation that enter the water flow as it rotates. This prevents foreign objects from becoming entangled in the blade or the rotation from being suddenly obstructed, making it possible to maintain stable rotation of the water turbine. Furthermore, since the flywheel is fixed to the second rotating shaft so that it rotates together with it at all times, even if the blade collides with foreign matter and the load temporarily increases, the inertial force of the flywheel can suppress a sudden deceleration of the rotation. As a result, the foreign matter cutting action by the leading edge of the blade can be performed more reliably, and the rotation of the water turbine can be prevented from becoming significantly disturbed. In conventional hydroelectric and wind power generation systems, when a flywheel is used, it has been common practice to connect it to the turbine's rotating shaft via a one-way clutch or the like so that it rotates together with the shaft during acceleration and disengages during deceleration, in order to improve the continuity of power generation and smooth the power output. This configuration is intended to improve the continuity and stability of the rotation of the power generation shaft by not transmitting the resistance received by the turbine to the flywheel. In contrast, the hydroelectric power generation system described in [1] above overturns this common practice, and the flywheel is provided to rotate together with the power generation system's rotating shaft at all times, including during acceleration and deceleration. With this configuration, the inertial force of the flywheel acts effectively when the blades collide with foreign objects, further enhancing the foreign object cutting action of the blade's leading edge.

[0011] [2] The front end of the blade has a front end surface on the side in the predetermined direction of rotation, The hydroelectric power generation apparatus according to [1], wherein the front end surface has a predetermined width in the thickness direction of the blade, corners are formed at both ends in the thickness direction, and the main surface of the blade is formed extending from each of the corners in the opposite direction to the predetermined rotation direction.

[0012] In the hydraulic power generation device described in the above [2], two corners are formed on the front end surface of the blade, and the main surface of the blade extends backward from each corner. Therefore, with respect to foreign objects, the blade can exhibit both the action of cutting at the two corners and the action of pushing through at the front end surface.

[0013] <First Embodiment> The following description relates to the hydraulic power generation device 100 according to the first embodiment.

[0014] As shown in FIG. 1, the hydraulic power generation device 100 includes a power generation unit 20 (power generation device) including a waterwheel 10 and a flywheel 22, and a connecting means 30 that connects the rotation shaft 11 (first rotation shaft portion) of the waterwheel 10 (see FIG. 2) and the rotation shaft 21 (second rotation shaft portion) of the power generation unit 20 so as to always rotate integrally with the axes x1 and x2 thereof aligned with each other.

[0015] In FIGS. 1 and 2, the left side is the front side of the hydraulic power generation device 100, the right side is the rear side, and the front-rear direction is illustrated as X. In FIG. 3, the left side is the left side of the hydraulic power generation device 100, the right side is the right side of the hydraulic power generation device 100, and the left-right direction is illustrated as Y. The up-down direction in FIGS. 1 to 3 is the height direction Z of the hydraulic power generation device 100.

[0016] In the present embodiment, the hydraulic power generation device 100 is fixedly installed on the base member 9. The base member 9 has a flat installation portion 90 that fixes a water flow introduction portion 1 that houses the waterwheel 10 therein, a power generation case body 2 that houses the power generation unit 20 therein, etc. with fastening members such as bolts and nuts, and a plurality of leg portions 91 that extend downward from the installation portion 90. The hydraulic power generation device 100 is installed on the installation portion 90 located above the ground surface 92.

[0017] As shown in Figure 2, a flow path is formed inside the water flow introduction section 1, from the water inlet 1A to the water outlet 1B. The water turbine 10 has a plurality of blades 12 (wings) that rotate in response to the water flow through the flow path, and a rotating shaft 11 that rotates due to the rotation of the blades 12. Each blade 12 is provided to rotate integrally with the rotating shaft 11 around its axis x1 (circumferential direction). The water turbine 10 is configured such that the blades 12 generate rotational force when they receive water flow, and this rotational force is transmitted to the rotating shaft 11 via the rotating center 13. Specifically, the blades 12 are fixed to the rotating center 13 (hub) provided on the tip side (front side) of the rotating shaft 11. The rotating center 13 is fixed to the rotating shaft 11 by fastening with bolts and nuts, etc., and is mounted to rotate integrally with the rotating shaft 11.

[0018] In this embodiment, the water flow introduction section 1 has an inlet 1A that opens upward and receives the water flow downward (to the lower side in Figure 1), a main section 1C that has a water turbine 10 inside, and an outlet 1B that drains the water flow received by the water turbine 10 and sent forward (to the left side in Figure 1) towards the front (diagonally downward or downward). As shown in Figure 3, the inlet 1A is positioned to one side (here to the right) in the left-right direction Y with respect to the axis x1 of the rotation axis 11 in order to rotate the blades 12 of the water turbine 10 in a predetermined rotation direction C. The main section 1C introduces the water flow received from the inlet 1A downward, receives it with the blades 12 of the water turbine 10 inside and converts it into rotational force, and also discharges the water flow received by the rotation of the blades 12 towards the outlet 1B. The water inlet 1A is connected to the water inlet pipe 101 (water supply pipe) from above, and the water outlet 102 is connected to the water outlet 1B facing forward (diagonally downward or downward).

[0019] As shown in Figure 5, multiple blades 12 are provided around the rotation axis 11 (see Figure 2). Each blade 12 has a forward-diagonal outward projection shape, extending radially from the inside to the outside and forward (left side in Figure 1), perpendicular to the direction of the axis x1 of the rotation axis 11 (first axial direction). All blades 12 have the same shape and are arranged at equal intervals around the axis x1. Each blade 12 has a front end surface 12f at its front end, which serves as the tip surface on the rotation direction C side. Each front end surface 12f has a predetermined width in the thickness direction of the blade 12 and has corners 12f1 and 12f2 at both ends in the thickness direction. Each front end surface 12f has one main surface 12a and the opposite main surface 12b of the blade 12, which extend from their respective corners 12f1 and 12f2 in the direction opposite to the rotation direction C. The main surfaces 12a and 12b of the blade 12 form curved surfaces that bulge outward in the radial direction and extend in the rotation direction C. In addition, each blade 12 has an outer end surface 12e which serves as the outer tip surface in the radial direction. The outer end surface 12e is formed as a trapezoidal surface with the front end surface 12f as the short side and the rear end edge as the long side.

[0020] The rotating center 13 is a frustoconical structure, and its outer surface 13a is curved inward radially along its entire circumference. A circular opening 13h is formed at the top, through which the front end of the rotating shaft 11 is inserted from the rear and fixed by fastening with bolts, nuts, etc. Each blade 12 has a shape that extends diagonally outward from the outer surface 13a.

[0021] The power generation unit 20 (generator) is positioned behind the water turbine 10 (water flow introduction section 1). As shown in Figure 4, the power generation unit 20 has a configuration in which a flywheel 22 and a power generation section 23 (power generation device) are housed inside the power generation case body 2, and these are rotationally driven by a rotating shaft 21 (generator shaft).

[0022] The power generation case body 2 is a sealed enclosure that houses the flywheel 22 and the power generation unit 23. The rotating shaft 21 penetrates the power generation case body 2 in the direction of its axis x2 (second axis direction) and is attached to the power generation case body 2 via a bearing device 21R. The bearing device 21R is a sealed bearing device equipped with sealing functions such as a seal device (O-ring, etc.) or grease. The inside of the power generation case body 2 is under reduced pressure, reducing the rotational resistance of the internal rotating parts (flywheel 22 and rotor 23R). The power generation case body 2 of this embodiment includes a connecting means 30 that connects the rotating shaft 11 and the rotating shaft 21.

[0023] The flywheel 22 is a rotating weight body having a weighted section 22W on its outer circumference or the like. The flywheel 22 is mounted so as to rotate integrally with the rotating shaft 21 at all times, including when the rotating shaft 21 is increasing speed, decreasing speed, or maintaining a constant speed in a predetermined rotation direction C. Specifically, the flywheel 22 and the rotating shaft 21 are connected by well-known means such as key coupling, spline fitting, or fastening and fixing with bolts and nuts.

[0024] The power generation unit 23 is a power generation device that generates electricity based on the rotation of the rotating shaft 21. In this embodiment, the power generation unit 23 generates electricity based on the rotation of a flywheel 22 that rotates integrally with the rotating shaft 21. Specifically, the power generation unit 23 has a rotor 23R that rotates integrally with the flywheel 22 in the same axis, and generates electricity by the rotation of the rotor 23R accompanying the rotation of the flywheel 22.

[0025] In this embodiment, the power generation unit 23 is arranged within the power generation case body 2, with a rotor 23R (generator rotor) that can rotate integrally with the flywheel 22 around the axis of the rotating shaft 21, and a stator 23S (generator stator) that does not rotate relative to the rotor 23R, both having the same axis as the rotating shaft 21. The rotor 23R is arranged in a ring and is configured as a rotating body that is integrated with the flywheel 22. Multiple magnetic members 23m (magnetic field forming parts), such as electromagnets or permanent magnets like neodymium magnets, are provided on the rotor 23R at predetermined intervals along its circumferential direction. The stator 23S is arranged in a ring and has stator coils 23c that face the magnetic members 23m of the rotor 23R across an air gap. The stator 23S is fixed inside the power generation case body 2 and is held in a non-rotating position relative to the flywheel 22. As the rotation of the rotating shaft 21 and the flywheel 22 occurs, relative rotation occurs between the magnetic members 23m and the stator coils 23c, and this relative rotation generates electricity. Here, the ratio of the number of magnetic members 23m to stator coils 23c is set to 3:4, and three-phase AC power is output from the stator coils 23c. The power generated by the power generation section 23 of the power generation unit 20 is input to the output section 60 shown in Figure 1.

[0026] As shown in Figure 1, the output unit 60 is a well-known inverter control device having an output circuit that enables the output of three-phase AC power generated by the power generation unit 20 as DC power at a predetermined voltage. The power output from the output unit 60 may be converted to grid power and supplied to an external power system, or it may be supplied to a battery (energy storage means) for storage. Alternatively, it may be input to a power conditioner and converted to AC power usable in a home.

[0027] The connecting means 30 connects the water turbine 10 and the power generation unit 20. The connecting means 30 directly connects the rotating shaft 11 (rotating output shaft) of the water turbine 10 and the rotating shaft 21 of the power generation unit 20 so that they rotate coaxially and as a single unit at all times. In this embodiment, the front end of the rotating shaft 21 is connected to the rear end of the rotating shaft 11. The connecting means 30 in this embodiment is a well-known shaft coupling for coaxially connecting the rotating shaft 11 and the rotating shaft 21 and for rotating both shafts as a single unit. A flywheel 22 is fixed to the rotating shaft 21, which rotates as a single unit at all times, including during acceleration and deceleration, and the deceleration due to rotational fluctuations of the water turbine 10 can be suppressed by inertial force. Note that the connecting means 30 may be a well-known shaft coupling means such as a key coupling, spline fitting, or fastening and fixing with bolts and nuts.

[0028] <Example of effect> In the hydroelectric power generation device 100, the blades 12 of the water turbine 10 are provided with a front end shape in which the thickness decreases towards the front end. This allows the front end of the blade to cut through foreign objects such as vegetation that enter the water flow as it rotates. This prevents foreign objects from becoming entangled in the blades or the rotation from being suddenly obstructed, making it possible to maintain stable rotation of the water turbine 10.

[0029] Furthermore, in the hydroelectric power generation device 100, the flywheel 22 is fixed to the rotating shaft 21 so that it rotates together with the shaft at all times, including during acceleration and deceleration. Therefore, even if the blade 12 collides with foreign matter and the load temporarily increases, the inertial force of the flywheel 22 can suppress a sudden deceleration of the rotation. As a result, the foreign matter cutting action by the leading edge of the blade is more reliably performed, and the rotation of the water turbine 10 is prevented from becoming significantly disturbed.

[0030] Conventionally, it was common technical practice to connect the flywheel to the rotating shaft on the turbine side via a one-way clutch or the like, and to disconnect it during deceleration. In contrast, the hydroelectric power generation device 100 of this embodiment does not adhere to this common technical practice, and the flywheel 22 is fixed to the rotating shaft 21 on the power generation unit 20 side so as to rotate together with it at all times. As a result, the inertial force of the flywheel 22 can be actively utilized when a foreign object collides with it, and the foreign object cutting action of the blade front end can be further enhanced.

[0031] <Other Embodiments> This disclosure is not limited to the embodiments described above and in the drawings. For example, any combination of the features of the embodiments described above or below is possible as long as it does not contradict each other. Furthermore, any feature of the embodiments described above or below may be omitted unless explicitly stated as essential. Moreover, the embodiments described above may be modified as follows.

[0032] In the above-described embodiment, the rotating shaft 11 and the rotating shaft 21 were connected, but both may be formed as a single integrated shaft material (rotating shaft portion).

[0033] In the above-described embodiment, the blade 12 has a thickness that decreases towards the front end, at least at the front end. Furthermore, the blade 12 in the above-described embodiment has a shape in which the thickness decreases towards the front end and increases towards the rear end, not only at the front end (front end side) but throughout the entire blade 12. The shape of the blade 12, such as the width dimension of the front end surface, the shape of the corners, and the inclination angle of the main surface, may be changed as appropriate. For example, as shown in Figure 6, the front end of the blade 12 may be formed to form a corner 12d. The material of the blade 12 may also be arbitrarily selected as long as it has the required strength and wear resistance. Furthermore, the front end of the blade 12 may be provided such that its width in the direction perpendicular to the thickness direction narrows as it approaches the front end surface 12f or front end 12d. This allows for greater pressure to be applied when it comes into contact with foreign matter, thereby enhancing the foreign matter cutting effect. Furthermore, the front end of the blade 12 may be provided such that its width increases in a direction perpendicular to the thickness direction as it approaches the front end surface 12f or front end 12d. This allows for the removal of foreign matter over a wider area.

[0034] In the embodiment described above, the flywheel 22 has a weight portion 22W on its outer circumference and is integrated with the rotor 23R, but the shape, mass distribution, arrangement of the weight portion 22W, positional relationship with the rotor 23R, etc. can be changed as appropriate.

[0035] The shape of the water flow introduction section 1 and the positions and angles of the water inlet 1A and water outlet 1B in the above-described embodiment can also be appropriately changed within a range that allows the blade 12 to rotate in a predetermined rotational direction.

[0036] Regarding the configuration of the power generation unit 23 in the above-described embodiment, well-known power generation mechanisms such as permanent magnet type, excitation type, and changes in the number of poles and turns can be appropriately adopted.

[0037] The hydroelectric power generation device disclosed herein is a relatively small hydroelectric power generation device (small-scale hydroelectric power generation device) that is installed in mountainous areas where trees grow densely around the water flow and there are many natural objects such as large stones and rocks, but it can of course also be installed in irrigation channels in agricultural land. The hydroelectric power generation device can be installed if there is a water flow with a small drop, for example, of about 5m. A water flow with a small drop does not have to be a water flow that falls straight down, but can be an inclined water flow. In this case, the drop refers to the difference (height difference) between the highest and lowest points of the inclined water flow, and not the straight-line distance of the slope from the highest point to the lowest point. Note that the hydroelectric power generation device disclosed herein may be other hydroelectric power generation devices different from those described above.

[0038] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is not limited to the embodiments disclosed herein, and is intended to include all modifications within the scope of the claims or equivalents thereof. [Explanation of Symbols]

[0039] 100 Hydroelectric power plants 1. Water flow inlet 2. Power generation case 10 Waterwheels 11. Rotation axis (first rotation axis section) 12 Blades (wing section) 12f front end surface 12f1, 12f2 Corner of the front end face 12a, 12b main surface 12e Outer end surface 13. Center of rotation (hub) 20. Power generation unit (generator, power generation device) 21. Rotation axis (generator axis, second rotation axis section) 22 Flywheel 23 Power Generation Department 30 Connecting means (couplings, etc.) 60 Output section (inverter-controlled equipment) X Anteroposterior direction (axial direction) Y left / right direction Z (height direction) C Rotation direction

Claims

1. A water turbine in which the blades receive a water flow and the first rotating shaft rotates integrally with the blades in a predetermined rotational direction, A hydroelectric power generation apparatus comprising: a power generation device that generates electricity based on the rotation of a second rotating shaft that rotates in conjunction with the first rotating shaft, The first rotating shaft portion and the second rotating shaft portion rotate together as a single unit, coaxially with each other. A flywheel is fixed to the second rotating shaft so as to rotate together with it at all times, including during acceleration and deceleration. The blade has a front end shape in which the thickness decreases towards the front end at least at the front end in the predetermined rotation direction, and contributes to cutting foreign objects mixed in the water flow. Hydroelectric power generation device.

2. The front end of the blade has a front end surface on the side in the predetermined direction of rotation, The hydroelectric power generation apparatus according to claim 1, wherein the front end surface has a predetermined width in the thickness direction of the blade, corners are formed at both ends in the thickness direction, and the main surface of the blade is formed extending from each of the corners in the opposite direction to the predetermined rotation direction.

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