JP6055266B2 - Axial turbine generator - Google Patents

Description

  Embodiments of the present invention relate to an axial-flow turbine generator.

  From the viewpoint of preventing global warming, the active use of renewable energy has long been screamed. Among the many renewable energy sources, hydropower has been actively developed and used since ancient times. However, because the mainstream is large-scale centralized power generation using dams, there are few construction sites suitable for new development, and new construction is difficult due to concerns about environmental impact. For these reasons, there is a demand for a shift from large-scale centralized power generation to medium- and small-scale distributed power generation with abundant undeveloped points. One of the small and medium-scale distributed power generation is a power generation system that uses ultra-low-drop hydropower without using a large-scale facility such as a dam.

  An example of a water turbine suitable for use with ultra-low head hydropower is an axial water turbine having a horizontal axis lift type runner. This axial-flow turbine is much more efficient than vertical-axis turbines such as Darius turbines and Savonius turbines. In addition, axial water turbines are relatively inexpensive to manufacture due to recent advances in production technology and technological innovations such as the development of new materials.

  In the case of an axial water turbine having such a horizontal axis lift type runner, its output is proportional to the cube of the inflowing flow velocity. For this reason, in order to increase the output of the axial turbine, it is desirable to install it at a point where the flow velocity is fast. However, such points are limited, and depletion of installable points is a matter of time. In addition, from the viewpoint of the scale of ultra-low head hydraulic power, it is predicted that the application of nano / pico turbines with a power generation capacity of 10 kW or less will increase. In the case of such a nano / pico turbine, the facility cost is relatively large with respect to the power generation amount. When considering application to nano / pico turbines, it is necessary to keep manufacturing, installation, and maintenance costs low, as well as improving hydraulic efficiency, for turbines installed at extremely low-head and large-flow points.

  Patent Documents 1 and 2 propose axial water turbines for the purpose of improving the output.

Japanese Patent No. 4001485 JP-A-2005-240786

  However, in patent document 1, the rotor of the generator is installed in the front-end | tip part of a runner. This inevitably increases the moment of inertia of the runner. Further, when a permanent magnet generator is used, it is greatly affected by the cogging torque of the generator. For this reason, in terms of performance, there is a problem with self-startability.

  The power generation device of Patent Document 2 is applied to tidal power generation. However, in the power generation apparatus, the runner is disposed in a straight pipe portion provided on the downstream side of the diffuser pipe. For this reason, there exists a problem that the speed-up effect of a diffuser pipe | tube cannot fully be acquired.

  The present invention has been made in consideration of such points, and an object thereof is to provide an axial-flow turbine generator that can increase the speed of flowing water flowing into a runner and improve self-starting performance. To do.

  The axial-flow turbine generator according to the embodiment is immersed in running water and generates power using running water. This axial-flow turbine power generator is disposed inside the outer cylindrical body, an outer cylindrical body extending in the main flow direction of the flowing water, an inner cylindrical body provided at least partially inside the outer cylindrical body, And a runner rotatably provided on the inner cylindrical body. Of these, the runner is rotated by running water around a rotation axis extending in the main flow direction. A generator that generates power by rotating the runner is built in the inner cylindrical body. The outer cylindrical body gradually expands in the mainstream direction.

FIG. 1 is a cross-sectional view showing an axial-flow turbine power generator in a first embodiment installed in a water channel. FIG. 2 is a front view of the axial-flow turbine power generator of FIG. 1 as viewed from the upstream side in the mainstream direction. FIG. 3 is a diagram illustrating an axial-flow turbine power generator according to the second embodiment. FIG. 4 is a partial cross-sectional view of the axial-flow water turbine generator of FIG. FIG. 5 is a diagram illustrating a modification of the axial-flow turbine power generator in the second embodiment. FIG. 6 is a diagram illustrating an axial flow turbine power generator according to the third embodiment. FIG. 7 is a partial cross-sectional view of the axial-flow turbine power generator in the fourth embodiment.

(First embodiment)
The axial-flow turbine generator apparatus in the 1st Embodiment of this invention is demonstrated using FIG. 1 and FIG. An axial-flow turbine power generator can be installed in a waterway or a river, and is an apparatus for generating electricity by running water immersed in running water.

  As shown in FIGS. 1 and 2, the axial flow turbine power generator 10 includes at least one diffuser pipe (outer cylindrical body) 11 extending in a main flow direction (direction of water flow in a water channel 1 described later) P. And an inner cylinder (inner cylindrical body) 13 provided inside the diffuser pipe 11. Of these, the diffuser pipe 11 gradually expands in the mainstream direction P.

  That is, the outer diameter of the diffuser pipe 11 gradually increases from the upstream side in the main flow direction P toward the downstream side. Similarly, the inner diameter of the diffuser pipe 11 gradually increases from the upstream side toward the downstream side. That is, the in-tube flow path 12 is formed inside the diffuser pipe 11, and the flow area of the in-tube flow path 12 gradually increases from the upstream side toward the downstream side. In addition, it is preferable that the cross section along the mainstream direction P of the diffuser pipe | tube 11 has a streamline shape as a whole, as shown in FIG. Thereby, it can suppress that the flow along the inner surface 11a and the outer surface 11b of the diffuser pipe | tube 11 peels.

  In addition, FIG. 1 shows an example in which the entire inner cylinder 13 is disposed inside the diffuser pipe 11. However, the present invention is not limited to this, and the inner cylinder 13 may extend from the inside of the diffuser pipe 11 to the downstream side of the diffuser pipe 11. In addition, in order to suppress that the flowing water which flows through the pipe internal flow path 12 is disturb | confused, it is suitable for the inner cylinder 13 to have a streamlined shape as a whole.

  Here, in FIG. 1 and FIG. 2, as an example, an example in which the axial-flow turbine generator 10 is installed in the water channel 1 is shown. In this case, the installation base 5 is installed on the ground 2 on both sides of the water channel 1, and the inner cylinder 13 is fixed to the installation base 5 via the fixing member 6. The diffuser pipe 11 is fixed to the inner cylinder 13 via, for example, a spoke-like member (not shown). In this way, the axial-flow turbine generator 10 is immersed in the running water of the water channel 1. The fixing member 5 and the spoke-like member are preferably provided on the downstream side of the inner cylinder 13 in order to prevent the flow of the in-pipe flow path 12 from being disturbed.

  A runner (horizontal shaft lift type runner) 14 is rotatably provided in the inner cylinder 13. The runner 14 is disposed entirely inside the diffuser pipe 11 (that is, the pipe flow path 12), and is rotated by running water flowing through the pipe flow path 12 around the rotation axis X extending in the main flow direction P. ing. In this way, the runner 14 converts the kinetic energy of running water into rotational energy. The runner 14 preferably has a plurality (two in this case) of runner blades 14a.

  A generator 15 is built in the inner cylinder 13. Similarly, the generator 15 is connected to the runner 14 via a connecting shaft 16 built in the inner cylinder 13. In this way, the rotation of the runner 14 is transmitted to the generator 15 via the connecting shaft 16, and the generator 15 is configured to generate power by the rotation of the runner 14.

  The effect | action of this Embodiment which consists of such a structure is demonstrated.

  When the axial turbine generator 10 is immersed in flowing water in the water channel 1, part of the flowing water flows through the in-pipe channel 12. The runner 14 is rotated by the flowing water flowing through the in-pipe channel 12.

  The remaining flowing water flows along the outer surface 11 b of the diffuser pipe 11 that gradually expands in the main flow direction P outside the diffuser pipe 11. Thus, the flowing water outside the diffuser pipe 11 flows in a direction away from the rotation axis X of the runner 14. For this reason, the flowing water in the pipe flow path 12 in the outlet side region of the diffuser pipe 11 is drawn to the outside of the diffuser pipe 11 by the flowing water outside the diffuser pipe 11, and the pressure in the pipe flow path 12 is reduced. The pressure difference increases between the 12 inlet side regions and the outlet side region. As a result, the speed of the flowing water flowing through the in-pipe flow path 12 increases, and the rotation speed of the runner 14 increases.

  When the runner 14 rotates, the rotation of the runner 14 is transmitted to the generator 15 via the connecting shaft 16 built in the inner cylinder 13. In this way, power is generated by the generator 15.

  Thus, according to this Embodiment, the runner 14 is arrange | positioned in the flow path 12 in the pipe | tube formed inside the diffuser pipe | tube 11 immersed in flowing water and expanding gradually in the mainstream direction P. As shown in FIG. Accordingly, as described above, the speed of the flowing water flowing through the in-pipe channel 12 of the diffuser pipe 11 can be increased. That is, the speed of the flowing water flowing into the runner 14 is increased, the rotational speed of the runner 14 is increased, and the amount of power generated by the generator 15 can be increased.

  Further, according to the present embodiment, the runner 14 is rotatably provided in the inner cylinder 13, and the generator 15 is built in the inner cylinder 13. As a result, an increase in the moment of inertia of the runner 14 can be suppressed, and the self-starting property can be improved.

(Second Embodiment)
Next, the axial-flow water turbine generator in the 2nd Embodiment of this invention is demonstrated using FIG. 3 and FIG.

  The second embodiment shown in FIGS. 3 and 4 is mainly different in that an ejection mechanism for ejecting water is provided, and other configurations are the same as those in the first embodiment shown in FIGS. 1 and 2. It is almost the same as the form. 3 and 4, the same parts as those of the first embodiment shown in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIGS. 3 and 4, the axial turbine generator 10 is provided on the inner surface 11 a of the diffuser pipe 11, and a bulging portion 21 that swells smoothly toward the inside of the diffuser pipe 11, and jets water. And a jetting mechanism 22 for performing the above operation. Of these, the bulging portion 21 is disposed upstream of the runner 14. Further, the bulging portion 21 is formed over the entire circumference of the diffuser pipe 11, that is, in an annular shape, and is formed integrally with the diffuser pipe 11.

  The ejection mechanism 22 is provided in the diffuser pipe 11, a water intake pipe 23 that supplies water to a later-described jet outlet 25, a cavity portion 24 that communicates with the water intake pipe 23, a diffuser pipe 11, and a cavity portion 24. And a jet nozzle 25 communicating with the nozzle. Among these, the intake pipe 23 takes in water having a larger potential energy than flowing water flowing inside the diffuser pipe 11 (intra-pipe flow path 12), and supplies the taken-in water to the jet outlet 25 through the cavity portion 24. It is like that. The intake pipe 23 is preferably extended to the upstream side of the diffuser pipe 11 so as to take in the flowing water on the upstream side of the axial flow turbine power generator 10. For example, as shown in FIG. 3, when the weir 3 is provided on the upstream side of the axial turbine generator 10, the intake pipe 23 can be configured to take in the flowing water that flows over the weir 3. . Thereby, the intake pipe 23 can take in water having relatively large potential energy and supply the taken-in water to the jet outlet 25.

  As shown in FIG. 4, the cavity 24 of the ejection mechanism 22 is formed in the upstream portion of the diffuser pipe 11 so as to have a relatively large capacity. On the other hand, the jet outlet 25 is formed so that a flow path area may become small. As a result, the flow of water through the spout 25 is restricted. Further, the water in the cavity 24 is pressurized by the water supplied from the intake pipe 23. That is, since the intake pipe 23 takes in water having a large potential energy and supplies it to the cavity 24 as described above, the water in the cavity 24 is pressurized. As a result, the water pressurized in the cavity 24 is ejected to the surface 21a of the bulging portion 21 (the inner surface of the diffuser pipe 11) through the ejection port 25. The hollow portion 24 and the ejection port 25 are formed over the entire circumference of the diffuser pipe 11, that is, in an annular shape, and are formed integrally with the diffuser pipe 11.

  The ejection port 25 of the ejection mechanism 22 is disposed on the upstream side of the bulging portion 21. Moreover, the bulging part 21 and the jet nozzle 25 are close to each other. The ejection port 25 ejects water in the main flow direction P along the surface 21 a of the bulging portion 21.

  In the axial flow turbine power generation device 10 according to the present embodiment, when water is taken into the intake pipe 23 from the weir 3 provided on the upstream side of the axial flow turbine power generation device 10, the taken water is supplied to the cavity portion 24. The The water in the cavity portion 24 is pressurized and ejected from the ejection port 25 along the surface 21a of the bulging portion 21 in the main flow direction P.

  In this case, a high-speed jet Q is formed by the water jetted from the jet nozzle 25. The high-speed jet Q becomes a flow along the surface 21a of the bulging portion 21 due to the Coanda effect. The high-speed jet Q that has flowed through the surface 21 a of the bulging portion 21 then flows along the inner surface 11 a of the diffuser pipe 11. As a result, the pressure decreases in the jet region where the jet Q is formed, and a pressure difference is generated between the jet region and the surrounding region around the jet region. For this reason, the flowing water in the surrounding region is drawn into the jet region by the pressure difference and the viscosity of the water, and the speed of the flowing water flowing through the in-pipe channel 12 can be further increased.

  Thus, according to the present embodiment, the ejection mechanism 22 has the ejection port 25 that ejects water in the main flow direction P along the bulging portion 21 provided on the inner surface 11 a of the diffuser pipe 11. As a result, as described above, the speed of flowing water flowing through the in-pipe channel 12 can be further increased, and the speed of flowing water flowing into the runner 14 can be further increased. For this reason, the rotational speed of the runner 14 can be further increased, and the amount of power generated by the generator 15 can be further increased.

  Moreover, the bulging part 21 is arrange | positioned upstream from the runner 14 like this Embodiment. Thereby, the speed of the flowing water flowing into the runner 14 can be further increased.

  Moreover, the bulging part 21 and the jet nozzle 25 are formed over the perimeter of the diffuser pipe | tube 11 like this Embodiment. As a result, the jet Q along the surface 21a of the bulging portion 21 can be formed over the entire circumference of the diffuser pipe 11, and the flow velocity of the flowing water flowing through the pipe flow path 12 can be increased as a whole. For this reason, the speed of the flowing water flowing into the runner 14 can be further increased.

  Further, as in the present embodiment, the jet Q along the surface 21a of the bulging portion 21 can be formed using the flowing water in the water channel 1 in which the axial-flow turbine generator 10 is installed. Thereby, the kinetic energy which the flowing water which flows through the water channel 1 has can be used effectively.

  In the present embodiment described above, an example in which the weir 3 is provided on the upstream side of the axial-flow turbine generator 10 and the intake pipe 23 is configured to take in the flowing water that flows over the weir 3. explained. However, the present invention is not limited to this, and the intake pipe 23 may be another water channel or irrigation pond (none of which is not shown) at a higher elevation than the water channel 1 where the axial-flow turbine generator 10 is installed. You may make it take in the water. Even in this case, the water in the cavity 24 can be pressurized and water can be ejected from the ejection port 25.

  Moreover, in this Embodiment mentioned above, the example where the bulging part 21 was arrange | positioned upstream from the runner 14 was demonstrated. However, the present invention is not limited to this, and the bulging portion 21 may not be disposed on the upstream side of the runner 14. Even in this case, the speed of the flowing water flowing through the in-pipe flow path 12 can be increased by the jet Q formed along the surface 21 a of the bulging portion 21.

  Moreover, in this Embodiment mentioned above, the bulging part 21, the cavity part 24, and the jet nozzle 25 demonstrated the example formed cyclically | annularly over the perimeter of the diffuser pipe | tube 11. As shown in FIG. However, the present invention is not limited to this, and the bulging part 21, the cavity part 24, and the jet outlet 25 may be formed in a part of the diffuser pipe 11 in the circumferential direction. In this case, it is preferable to provide the bulging portion 21 and the jet outlet 25 close to each other along the main flow direction P, whereby a jet Q along the surface 21a of the bulging portion 21 can be formed. The speed of the flowing water flowing through the in-pipe channel 12 can be increased.

  Further, in the above-described embodiment, the example in which the bulging portion 21, the cavity portion 24 of the ejection mechanism 22 and the ejection port 25 are formed integrally with the diffuser pipe 11 has been described. However, the present invention is not limited to this, and the bulging portion 21, the cavity portion 24, and the ejection port 25 may be removable from the diffuser pipe 11. For example, in the form shown in FIG. 5, the diffuser pipe 11 has a diffuser pipe main body 31 and an upstream end portion 32 that is provided on the upstream side of the diffuser pipe main body 31 and is removable from the diffuser pipe main body 31. doing. The diffuser pipe main body 31 and the upstream end 32 are fixed to each other using a connecting member 33 and a bolt (not shown). The connecting member 33 is preferably provided in a part of the circumferential direction of the diffuser pipe 11 so as not to disturb the jet Q.

  In the form shown in FIG. 5, the bulging portion 21, the cavity portion 24, and the ejection port 25 described above are integrally formed at the upstream end portion 32. In this case, by removing the upstream end portion 32 from the diffuser tube main body 31, the bulging portion 21, the cavity portion 24, and the jet port 25 can be removed from the diffuser tube main body 31. Thereby, the maintenance of the ejection mechanism 22 can be performed while continuing the power generation by the axial-flow turbine generator 10.

(Third embodiment)
Next, the axial-flow water turbine generator in the 3rd Embodiment of this invention is demonstrated using FIG.

  The third embodiment shown in FIG. 6 is mainly different in that a pump is provided in a water intake pipe of an ejection mechanism that ejects water. The other configuration is the second configuration shown in FIGS. 3 and 4. This is substantially the same as the embodiment. In FIG. 6, the same parts as those of the second embodiment shown in FIGS. 3 and 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The ejection mechanism 22 further includes a pump (pressurization drive unit) 41 provided in the intake pipe 23. The water in the water intake pipe 23 is pressurized by the pump 41 and supplied to the cavity 24.

  In the present embodiment, the intake pipe 23 only needs to be configured to take in water at an arbitrary position. That is, the intake pipe 23 is not limited to the case where water having a larger positional energy than the flowing water flowing inside the diffuser pipe 11 (in-pipe flow path 12) is taken. The running water in the vicinity region not limited to the side and the downstream side) can be taken in. Even in this case, the taken-in water can be pressurized and supplied to the cavity 24 by the pump 41 provided in the intake pipe 23. In FIG. 6, the example which takes in flowing water from the downstream of the diffuser pipe | tube 11 is shown as an example.

  Thus, according to the present embodiment, the pump 41 is provided in the intake pipe 23 of the ejection mechanism 22. Accordingly, the water for forming the jet Q along the surface 21a of the bulging portion 21 is not limited to water having a desired potential energy, and water at an arbitrary position can be used. For this reason, it becomes possible to apply the axial-flow water turbine generator 10 by this Embodiment also to the river of the urban area where it is difficult to secure the water which has comparatively big potential energy, and can improve versatility. it can.

(Fourth embodiment)
Next, the axial-flow water turbine generator in the 4th Embodiment of this invention is demonstrated using FIG.

  The fourth embodiment shown in FIG. 7 is mainly different in that the cross section along the main flow direction of the diffuser pipe has an airfoil shape, and other configurations are shown in FIGS. 3 and 4. This is substantially the same as in the second embodiment. In FIG. 6, the same parts as those of the second embodiment shown in FIGS. 3 and 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 7, the cross section along the main flow direction P of the diffuser pipe 11 has an airfoil shape. More specifically, the diffuser tube 11 is formed such that the inner surface 11a of the diffuser tube 11 serves as a suction surface (back side surface) of the blade and the outer surface 11b of the diffuser tube 11 serves as a pressure surface of the blade. The swelled portion on the suction surface of the blade is the bulging portion 21 described above. The bulged portion 21 has a wing-shaped maximum thickness portion.

  Further, as shown in FIG. 7, the cavity 24 of the ejection mechanism 22 according to the present embodiment is formed in the diffuser pipe 11 from the upstream side to the downstream side. In this case, the mass of the diffuser pipe 11 can be reduced, which is convenient when, for example, the axial water turbine generator 10 is transported or installed. Moreover, the volume of the cavity 24 can be increased, and the amount of water in the cavity 24 can be increased.

  As described above, according to the present embodiment, the cross section of the diffuser pipe 11 along the main flow direction P has an airfoil shape. As a result, it is possible to suppress the separation of the jet Q formed along the surface 21a of the bulging portion 21, and to more effectively reduce the pressure in the jet region where the jet Q is formed. it can. For this reason, the speed of the flowing water flowing through the in-pipe channel 12 can be increased, and the speed of the flowing water flowing into the runner 14 can be further increased.

  As mentioned above, although embodiment of this invention was described in detail, the axial-flow water turbine generator by this invention is not limited to the said embodiment at all, and various in the range which does not deviate from the meaning of this invention. It can be changed.

DESCRIPTION OF SYMBOLS 10 Axial water turbine generator 11 Diffuser pipe | tube 11a Inner surface 13 Inner cylinder 14 Runner 15 Generator 21 Swelling part 21a Surface 22 Jet mechanism 23 Intake pipe 25 Spout 41 Pump

Claims (7)

In an axial-flow turbine generator that is immersed in running water and generates electricity by running water,
An outer cylindrical body extending in the mainstream direction of running water;
An inner cylindrical body provided at least partially inside the outer cylindrical body;
A runner disposed inside the outer cylindrical body and rotatably provided on the inner cylindrical body, the runner rotating with running water around a rotation axis extending in a main flow direction;
A generator built in the inner cylindrical body and generating power by rotation of the runner;
A bulging portion provided on the inner surface of the outer cylindrical body and bulging toward the inner side of the outer cylindrical body;
An ejection mechanism provided on the outer cylindrical body, and comprising an ejection mechanism for ejecting water ,
The outer cylindrical body gradually expands in the mainstream direction,
Wherein the ejection port of the ejection mechanism is disposed on the upstream side of the bulged portion, the shaft running water wheel power generator characterized by jetting water to the main flow direction along the surface of the bulging portion. The axial-flow turbine power generator according to claim 1 , wherein the bulging portion is disposed upstream of the runner. The bulge portion and the ejection port of the ejection mechanism, the axis running water vehicle generator according to claim 1 or 2, characterized in that it is formed over the entire circumference of the outer cylindrical member. The axial-flow water turbine generator according to any one of claims 1 to 3 , wherein the bulging portion and the ejection port of the ejection mechanism are removable from the outer cylindrical body. The jetting mechanism further includes a water intake pipe that takes in water having a larger positional energy than flowing water flowing inside the outer cylindrical body and supplies the taken water to the jet outlet. Item 5. The axial-flow water turbine generator according to any one of Items 1 to 4 . The jetting mechanism further includes a water intake pipe that supplies water to the jet outlet, and a pressure drive unit that is provided in the water intake pipe and pressurizes water in the water intake pipe. Item 5. The axial-flow water turbine generator according to any one of Items 1 to 4 . The axial-flow water turbine generator according to any one of claims 1 to 6 , wherein a section of the outer cylindrical body along the main flow direction has an airfoil shape.

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