JP6748480B2 - Vertical axis type hydroelectric power generation unit, Vertical axis type hydroelectric power generation unit - Google Patents

Description

The present invention relates to a vertical axis type hydroelectric power generation device and a vertical axis type hydroelectric power generation unit.

BACKGROUND ART Conventionally, there has been known a hydroelectric power generation device which generates electric power by rotating a blade of a water turbine by a water flow and transmitting the rotating motion to a generator. As a conventional small-sized hydroelectric power generation device, a "drop-type" turbine that dams a waterway to generate electric power and a "Savonius-type" turbine that generates electric power by a water flow drag have been widely used (for example, see Patent Document 1 below). .. However, if these turbines are to be installed in existing waterways, large-scale waterway remodeling work, etc., to prevent water from overflowing the waterways, is required. There were many constraints. Further, due to the characteristics of the water turbine, dust flowing through the water channel accumulates on the water turbine, which requires a dust remover and a large maintenance cost. In other words, the conventional hydroelectric power generation device has a factor that impedes its spread from the viewpoint of economic rationality, such as a large initial cost and a large maintenance cost.

As a method for solving the problems existing in the above-described conventional hydroelectric power generation devices, in recent years, realization of a vertical axis type hydroelectric power generation device utilizing lift characteristics has been studied. This vertical axis type hydroelectric generator is a generator that receives the rotational driving force from a water stream to generate electric power, a vertical rotation axis that is rotatably connected to the generator and that is installed vertically in the vertical direction. An apparatus comprising a plurality of blades arranged at substantially equal angular intervals along a circumferential direction around a vertical rotation axis, wherein the plurality of blades are arranged in a direction perpendicular to the water flow. Therefore, it has an advantage that a dust removing device and a large amount of maintenance cost, which are required in the related art, are not required.

JP, 2003-106247, A

However, although the blades arranged in the vertical direction, which are assumed by the vertical axis type hydroelectric power generation device, are often used for wind power generation, the current situation is that they have not spread to hydroelectric power generation devices. Because, unlike the wind (air) used in a wind turbine, the water flow (water) used in a water turbine has a density about 800 times that of air, so the load from the water flow constantly applied to the blade is extremely high. There is the challenge of growing. That is, if the output of the blade is increased in order to improve the power generation efficiency, a very large load is applied to the entire turbine even if it receives a force from running water with a constant flow velocity, and the fatigue load due to vibration causes There is also a big impact. In particular, in the case of a vertical axis type hydroelectric generator, the blades arranged in running water flowing through the water channel have a cantilever structure, so that in order to withstand a large load from the water flow and a fatigue load due to vibration, A strong structure is needed. In other words, although the existing vertical axis hydroelectric power generation device has a formal advantage that does not exist in other conventional hydroelectric power generation devices, it can increase the installation cost depending on the specifications as a vertical axis hydroelectric power generation unit. I was afraid.

The present invention has been made in view of the problems existing in the above-mentioned conventional techniques, and an object thereof is to ensure a sufficient output characteristic and to generate an exciting force (fatigue load) generated by the influence of water flow. ) Can be suppressed to a small value, and further, the mass of the structure and the installation cost of the entire apparatus can be minimized to provide a vertical axis type hydroelectric power generation device which has never been available.

The vertical axis hydroelectric generator according to the present invention includes a generator that receives a rotational driving force from a water stream to generate electric power, and a vertical rotation unit that is rotatably connected to the generator and vertically hung. A vertical axis type hydroelectric power generator comprising a shaft, and a plurality of blades arranged at substantially equal angular intervals along the circumferential direction around the vertical rotation axis, wherein the plurality of blades are in the vertical direction. Is formed as a straight blade having a cross-sectional shape of a wing shape and is formed by linearly extending to, and when viewed from the bottom side of the plurality of blades, the number of blades is 5 or less , Further, the plurality of blades are provided with a corner radius portion having a curved shape at one of the end portions extending in the vertical direction, the radius of curvature of the corner radius portion is R, the blade including the corner radius portion. When the total length is L, the inequality of 0.01L≦R≦0.20L is established, and further, the plurality of blades each have an outer shape of a substantially U shape. It is characterized by being configured .

According to the present invention, the vibration force (fatigue load) generated by the influence of water flow can be suppressed to a small level while ensuring sufficient output characteristics, and the mass of the structure and the installation cost of the entire device are minimized. It is possible to provide a vertical-axis-type hydroelectric power generation device that has been heretofore available and that can be suppressed to the limit.

It is an appearance perspective view showing the whole vertical axis type hydroelectric power generation unit composition concerning this embodiment. It is a figure which illustrates the airfoil shape applicable to the vertical axis type hydroelectric power generation device which concerns on this embodiment. FIG. 4 is a graph showing a state of an exciting force (N) with respect to position angles (deg) of a plurality of blades included in a water turbine, and a partial diagram (a) in FIG. 3 shows a result when the number of blades is two. , (B) in FIG. 3 shows the result when the number of blades is five. It is a graph which showed the change of the bending moment (N*m) as a fatigue characteristic which acts on a vertical axis of rotation when the number of blades is increased one by one between 2 and 9. It is a graph which shows the result of having verified about the influence of the installation cost when the number of blades is increased one by one between 2 and 9. FIG. 9 is a graph showing different changes in bending moment (N·m) as a fatigue characteristic acting on the vertical rotation axis when the number of blades is even and when it is odd. It is a figure which shows the specific structural example of the external appearance shape which the vertical axis type hydroelectric power generation device which concerns on this embodiment can take. It is a figure which shows the specific structural example of the external appearance shape which the vertical axis type hydroelectric power generation device which concerns on this embodiment can take. It is a figure which shows the specific structural example of the external appearance shape which the vertical axis type hydroelectric power generation device which concerns on this embodiment can take. It is a figure which shows the specific structural example of the external appearance shape which the vertical axis type hydroelectric power generation device which concerns on this embodiment can take. It is a figure which shows the specific structural example of the external appearance shape which the vertical axis type hydroelectric power generation device which concerns on this embodiment can take. It is a figure which shows the specific structural example of the external appearance shape which the vertical axis type hydroelectric power generation device which concerns on this embodiment can take. It is a figure which shows the detailed structure of the braid|blade simple substance which concerns on this embodiment, The division view (a) in a figure shows the side view of one blade, and the division view (b) shows the top view of one blade. ing. It is the figure which showed the change condition of the load which acts when one blade rotates once. A safety factor for the fatigue limit of the stress generated in the corner portion of the blade, and a graph showing the output utilization rate, the ratio to the total blade length of the corner radius on the horizontal axis, the safety factor for the fatigue limit on the left vertical axis. The output utilization rate is shown on the right vertical axis. FIG. 16 is an enlarged graph of the graph shown in FIG. 15, showing a case where the safety factor for the fatigue limit on the left vertical axis in FIG. 15 is in the range of 0 to 4.

Hereinafter, preferred embodiments for carrying out the present invention will be described with reference to the drawings. Note that the following embodiments do not limit the invention according to each claim, and all combinations of the features described in the embodiments are not necessarily essential to the solution means of the invention. ..

First, an example of the overall configuration of the vertical axis type hydroelectric power generation unit 100 according to the present embodiment will be described. Here, FIG. 1 is an external perspective view showing an overall configuration of a vertical axis type hydroelectric power generation unit according to the present embodiment, and FIG. 2 is a blade type applicable to the vertical axis type hydroelectric power generation apparatus according to the present embodiment. It is a figure which illustrates a shape.

The vertical axis type hydroelectric power generation device 10 according to the present embodiment is a device that rotates the water turbine 11 configured by the blades 13 by a water flow and transmits the rotational motion to the generator 50 to generate electric power. As a specific configuration, as shown in FIG. 1, a vertical axis type hydroelectric generator 10 according to the present embodiment includes a water wheel 11 that rotates by a water flow, a vertical rotary shaft 20 on which the water wheel 11 is installed, and a vertical axis. The bearing support unit 30 includes a bearing that rotatably supports the rotating shaft 20, and a generator 50 that generates electric power by the rotational driving force of the vertical rotating shaft 20. The vertical axis type hydroelectric power generation device 10 according to the present embodiment is installed, for example, in a water channel.

Further, as the vertical axis type hydraulic power generation unit 100, a support body 60 that supports the water wheel 11 and the vertical rotation axis 20 that are rotating members and that is used to fix and install the vertical axis type hydraulic power generation apparatus 10 includes a vertical rotation axis 20 and a vertical rotation axis 20. It is installed so as to surround the bearing support portion 30, and a bridge portion 61 that is bridged over a water channel or the like is connected to the support body 60. The support 60 and the bridge portion 61 are fixedly installed to the foundation parts 62 provided on both banks of the irrigation canal, for example, so that the vertical axis type hydroelectric generation unit 100 according to the present embodiment is installed. There is.

The water turbine 11 illustrated in FIG. 1 has a plurality of blades 13 constituting the water turbine, which are arranged around the vertical rotation shaft 20 along the circumferential direction at substantially equal angular intervals, and in FIG. The case where the blade 13 is installed is illustrated. Each of these three blades 13 is configured to have an outer shape of a substantially U-shape, and is installed so that the substantially U-shaped open portion faces the vertical rotation shaft 20. In addition, a substantially U-shaped vertical rod portion is formed so as to extend in the vertical direction, and its transverse cross-sectional shape is formed as a straight blade having an airfoil shape. The vertically extending substantially U-shaped vertical rod portion formed as a straight blade functions as a blade portion of the water turbine 11. That is, in the water turbine 11 according to the present embodiment, as shown in FIG. 1, the three blades 13 are arranged in water and receive a force (water thrust force) from a water flow, thereby forming a straight line having an airfoil shape. The blade 12 as a wing receives a water flow to generate a lift, and rotates about the center of the water wheel 11 (vertical rotation axis 20) as a central axis.

As for the airfoil shape of the cross-sectional shape of the blade 13, as illustrated in FIG. 2, any type of airfoil shape can be adopted. For example, it is defined by NACA (National Advisory Committee for Aeronautics), which is the predecessor of NASA (National Aeronautics and Space Administration), as shown in diagram (a) in FIG. The airfoil “NACA0018” may be adopted, or the airfoil “TWT12013-05-BA642” developed at Tokai University, as shown in the diagram (b) in FIG. 2, may be adopted. ..

As described above, the vertical rotating shaft 20 is a member that has three blades 13 installed on the lower end side thereof and that receives the rotational force generated by the action of the blades 13 to rotate. The vertical rotation shaft 20 and the three blades 13 are securely fastened and fixed by a known fastening means such as a bolt and a nut. The vertical rotation shaft 20 is rotatably supported by a bearing provided in the bearing support portion 30.

The rotation of the vertical rotation shaft 20 is supported by the bearing support portion 30 and is transmitted to the generator 50, which causes the generator 50 to generate electric power. The generator 50 according to the present embodiment is installed such that an input shaft (not shown) of the generator 50 is coaxial with the vertical rotation shaft 20. However, when the generator 50 and the vertical rotation shaft 20 are connected by using a planetary gear or a speed reducer, an input shaft (not shown) of the generator 50 is arranged coaxially with the vertical rotation shaft 20. It doesn't have to be. Then, the generated power is transmitted to a power consumption place, a power storage means, etc. by a power transmission means (not shown).

The overall configuration example of the vertical axis hydraulic power generation unit 100 according to the present embodiment has been described above. Next, the results of experiments conducted by the inventors based on the above-mentioned vertical axis type hydroelectric power generation unit 100 will be described. The experimental results described below show that, while ensuring sufficient output characteristics, the vibration force (fatigue load) generated by the influence of water flow can be suppressed to a small level, and the mass of the structure and the installation cost of the entire device can be reduced. In order to obtain the vertical axis type hydroelectric power generation device 10 and the vertical axis type hydroelectric power generation unit 100 which can minimize the above, the inventors have first conceived and studied, and it is the result obtained. ..

First of all, among the influences that are a problem in the vertical axis type hydroelectric power generation device 10 and the vertical axis type hydroelectric power generation unit 100, the inventors of the present invention apply an exciting force (fatigue load) to the blade 13 of the water turbine 11 due to the thrust force of the water flow. I focused on the effect of. Then, the inventors analyzed the rotor characteristics (fatigue load characteristics) of the water turbine 11 having the blades 13 composed of straight blades from the theory of single flow control, and obtained the results shown in FIG. Here, FIG. 3 is a graph showing the state of the excitation force (N) with respect to the position angle (deg) of the plurality of blades 13 included in the water turbine 11, and the divisional diagram (a) in FIG. 3 is the number of blades. Shows the result when the number of blades is two, and the diagram (b) in FIG. 3 shows the result when the number of blades is five.

As shown in the diagram (a) in FIG. 3, when the number of blades is two, the fluctuation of the exciting force (N) applied to each blade 13 is very large, and it is added to these two blades 13. The total value of the excitation force (N) also had a very large amplitude variation as indicated by the arrow width indicated by the symbol α.

On the other hand, when the number of blades is 5, the fluctuation of the exciting force (N) applied to each blade 13 is relatively small as shown in the partial diagram (b) of FIG. It can be confirmed that the total value of the exciting force (N) applied to the element has a very small amplitude variation as indicated by the arrow width indicated by the symbol β by canceling the exciting force (N) with each other. It was

As can be seen from the above results, in the case of the water turbine 11 having two blades, the load amplitude per one rotation of the water turbine is about 350 N or more, whereas in the case of the water turbine 11 having five blades, the water turbine 1 The load amplitude per rotation was about 50 N or less, and there was a difference of about 7 times in the load amplitude of both. Therefore, in the vertical axis hydroelectric generator 10, it is possible to find a hypothesis that the larger the number of blades 13 is, the smaller the exciting force (fatigue load) generated on the blades 13 of the water turbine 11 is. it can.

Then, the inventors next examined what kind of difference the difference in the number of blades brings about in the bending moment (N·m) as the fatigue characteristic acting on the vertical rotary shaft 20. The result is shown in FIG. Here, FIG. 4 shows a change in bending moment (N·m) as a fatigue characteristic acting on the vertical rotation shaft 20 when the number of blades is increased by one between 2 and 9. It is a graph figure.

As shown in FIG. 4, as the number of blades increases from two to three, four, and five, the bending moment (N·m) as a fatigue characteristic acting on the vertical rotary shaft 20 decreases for a while. I was able to confirm that. However, it was confirmed that the bending moment (N·m) slightly increased when the number of blades was 6, compared with the case where the number of blades was 5. Further, when the number of blades is 6 or more, the bending moment (N·m) as a fatigue characteristic acting on the vertical rotary shaft 20 does not change so much, and the bending moment (N·m) increases due to the increase in the number of blades. It was confirmed that the impact would decrease. However, regarding the bending moment (N·m) when the number of blades is 6 or more, the bending moment (N·m) is greatly suppressed as compared with when the number of blades is 2, and the number of blades is at least 3 It has been confirmed that the bending moment (N·m) as the fatigue property acting on the vertical rotation shaft 20 can be significantly reduced by using more than one sheet.

Subsequently, the inventors decided to verify the influence of the installation cost, which is another factor that impedes the spread of the vertical axis hydraulic power generation device 10 and the vertical axis hydraulic power generation unit 100. The result is shown in FIG. Here, FIG. 5 is a graph showing the results of verifying the effect of the installation cost when the number of blades is increased by one from 2 to 9. For convenience of explanation, the graph showing in FIG. 5 also shows a graph showing changes in bending moment (N·m) as fatigue characteristics acting on the vertical rotation shaft 20 shown in FIG. It was decided to.

First, the inventors have found that by setting the number of blades to at least 3 or more, it is possible to reduce the bending moment (Nm) as a fatigue characteristic acting on the vertical rotation shaft 20, The idea was that the reduction of the moment (N·m) could reduce the mechanical mass of the hydraulic turbine of the vertical axis type hydroelectric generator 10 as a whole. Here, the “turbine mechanical mass” means the mass of the vertical axis type hydroelectric power generator alone excluding the blade portions (11, 13) and the bridge portions (60, 61) among the members shown in FIG. 1. Showing. This can be represented by the mass of a single body because the diameter of the shaft, which is the vertical rotary shaft 20, can be reduced as the number of blades increases. Then, considering the bending moment (N·m) as the fatigue characteristic, the design and study of the mass of the vertical axis type hydroelectric power generator alone was performed, and as a result, as shown in the partial diagram (a) in FIG. The value of the mechanical weight of the turbine was obtained for each number of sheets. Here, in the partial diagram (a) in FIG. 5, the water turbine mechanical mass is shown by a mass ratio that is an absolute value. As is clear from this figure, when the number of blades is three or more, the number of blades is three. It has been clarified that the mechanical mass of the water turbine can be greatly reduced as compared with the case of two. The tendency of the mass ratio of the mechanical mass of the water turbine is very consistent with the numerical tendency of the bending moment (N·m) as the fatigue characteristic, which is the result expected by the inventors.

Having obtained the above results, the inventors also conducted a study on the "bridge mass" defined by the bridge portion (60, 61). Then, after considering the bending moment (N·m) as the fatigue characteristic and designing and examining the “bridge mass” defined by the bridge portions (60, 61), the result is shown in the diagram (b) of FIG. As shown, the value of the bridge mass was obtained for each number of blades. Here, in the partial diagram (b) in FIG. 5, the bridge mass is shown by a mass ratio that is an absolute value, but as is clear from this figure, the “bridge mass” is also different from the case of the “turbine mechanical mechanical mass”. Similarly, when the number of blades is 3 or more, it is clear that the bridge mass can be greatly reduced as compared with the case where the number of blades is 2. The tendency of the mass ratio of the bridge mass was also in good agreement with the numerical tendency of the bending moment (N·m) as the fatigue property, which was the result expected by the inventors.

As described above, when the number of blades is three or more, the "turbine mechanical mass" and the "bridge mass" can be significantly reduced as compared with the case where the number of blades is two. It became clear. By significantly reducing the "turbine mechanical mass" and the "bridge mass", it should be possible to obtain the effect of reducing the installation cost. However, increasing the number of blades also leads to an increase in blade manufacturing cost. Therefore, the inventors have verified the influence of an increase in the blade manufacturing cost when the number of blades is increased from 2 to 9 one by one. A graph diagram showing the result is a partial diagram (c) in FIG.

Here, the blades 13 constituting the water turbine 11 are manufactured using a very expensive material such as CFRP (carbon-fiber-reinforced plastic), so that the increase in the number of blades is the same as the manufacturing cost. Will be proportionally affected. The result is shown in the subdivision (c) of FIG. 5, and it is clear that the increase in the number of blades proportionally increases the total cost of the turbine including the blades.

Then, the cost effect of the entire apparatus, which is the sum of the cost effect based on the “turbine mechanism mechanical mass” and the “bridge mass” described above and the cost effect based on the increase in the number of blades, is shown in the partial diagram (d) in FIG. .. As is clear from the diagram (d) in FIG. 5, as a result of confirming the total cost of the blade parts (11, 13), the water wheel mechanical parts (20, 30, 50), and the bridge parts (60, 61), The cost is suppressed when the number of blades is 3, 4, and 5. If the vertical axis type hydroelectric power generation unit 100 can be introduced at this installation cost, it will be profitable from the viewpoint of economic rationality, and so far. It has been clarified that the vertical axis type hydroelectric generation unit 100 according to the present embodiment can be introduced into familiar water channels that could not be introduced. On the other hand, when the number of blades is 2, 6 to 9, the cost is significantly increased, and it has been clarified that it is not economically reasonable in terms of installation cost. It should be noted that when the number of blades is 10 or more, it is clear that the blade manufacturing cost is increased as in the case of 6 to 9 blades, so that 10 or more blades are economically reasonable in terms of installation cost. do not do.

From the verification by the inventor described above, the vertical axis type hydroelectric power generation device 10 according to the present embodiment is optimal for the number of blades 13 constituting the water turbine 11 to be 3 to 5 blades. It became clear that the vertical axis type hydroelectric power generation unit 100 was obtained. That is, by introducing the vertical axis type hydroelectric generator 10 in which the number of the blades 13 constituting the water turbine 11 is 3 to 5, the vibration generated by the influence of the water flow is ensured while ensuring sufficient output characteristics. (EN) It is possible to provide a vertical axis type hydroelectric power generation unit 100 which is not available in the related art, in which the force (fatigue load) can be suppressed to a low level and the mass of the structure and the installation cost of the entire apparatus can be minimized. Becomes In addition, the verification contents using the single flow management theory by the inventors described with reference to FIGS. 3 to 5 are based on a completely new idea that has never existed in the field of the vertical axis hydroelectric generator. It should be added that the present inventors have newly made and obtained research results.

Now, the inventors who have obtained the above-mentioned new research results have examined and examined whether or not it is possible to further optimize the condition that the number of blades 13 constituting the water turbine 11 is 3 to 5. .. At that time, it was decided to re-verify the graph shown in FIG. 4 showing the change in the bending moment (N·m) as the fatigue characteristic acting on the vertical rotary shaft 20 for each number of blades. As a result, as shown in FIG. 6, it can be confirmed that the changing point of the bending moment (N·m) for each number of blades shows different tendencies when the number of blades is even and when it is odd. did it. Here, FIG. 6 is a graph showing different changes in the bending moment (N·m) as the fatigue characteristics acting on the vertical rotation axis when the number of blades is even and when it is odd.

That is, if the bending moment (N·m) values when the number of blades is an even number are connected by an imaginary line x, as indicated by the symbol x in FIG. 6, the number of blades is determined by the symbol y in FIG. When the bending moment (N·m) values for odd numbers are connected by the imaginary line y, the bending moment (N·m) values tend to be smaller than those for the even imaginary line x. I understand. Although a clear theoretical explanation of this fact is still insufficient, the inventors consider that when the number of blades is an even number, the blades 13 are arranged facing each other around the vertical rotation axis 20. Therefore, there will be a portion where the blade overlaps the water flow. As a result, the function of the blade is reduced and the effect of offsetting the effect of increasing the number of blades works, so that the bending moment (Nm) is greater when the number of blades is even than when it is odd. I think we will have a tendency to increase.

The virtual lines indicated by the symbols x and y in FIG. 6 can be drawn by using a known method such as the minimum two-row method as a means for calculating an approximated curve of a point sequence.

Based on the hypothesis using FIG. 6 described above, in the vertical-axis hydroelectric generator 10 according to the present embodiment, the number of blades 13 constituting the water turbine 11 is an odd number, that is, three or five blades. The optimal vertical-axis-type hydroelectric power generation unit 100 can be obtained by configuring with a number.

The preferred embodiment of the present invention has been described above. 7 to 12 are shown as configuration examples specifically exemplifying the vertical axis hydraulic power generation device 10 according to the present embodiment described above. Here, FIG. 7 to FIG. 12 are diagrams showing a specific configuration example of the external shape that can be taken by the vertical axis hydraulic power generation device 10 according to the present embodiment. 7 and 10 show the vertical axis type hydroelectric generator 10 in the case where the number of blades 13 constituting the water turbine 11 is three, and FIGS. 8 and 11 show the blades 13 constituting the water turbine 11. FIG. 9 shows a vertical axis type hydroelectric generator 10 when the number of blades is four, and FIGS. 9 and 12 show a vertical axis type hydroelectric generator 10 when the number of blades 13 constituting the turbine 11 is five. Showing.

Then, in the vertical axis hydraulic power generation device 10 shown in FIGS. 7 to 12, the solidity of the water turbine 11 configured by the plurality of blades 13 is configured to be 0.1 to 0.29. Here, the solidity is an index shown as a ratio of the total blade area to the rotating area of the blade, and is represented by the following mathematical expression (1).
Solidity (ρ)=n×C/(2πr) (1)
Here, n=number of blades, C=chord length (m), and r=turbine radius.

The above facts also show that the vertical axis type hydroelectric power generation device 10 and the vertical axis type hydroelectric power generation unit 100 according to the present embodiment can be obtained by configuring the solidity to be 0.1 to 0.29. ing. That is, when the solidity is 0.1 to 0.29 and the number of the blades 13 is 3 to 5, the exciting force generated by the influence of the water flow is ensured while securing sufficient output characteristics. (Fatigue load) can be kept small, and the mass of the structure and the installation cost of the entire apparatus can be minimized. 100 can be provided.

As described above, the invention matters described with reference to FIGS. 3 to 6 pay attention to the influence of the exciting force (fatigue load) generated on the blade 13 of the water turbine 11 by the thrust force of the water flow, and the “turbine mechanical mass” and “ It was derived by considering the cost effect of the entire device, which is the sum of the cost effect based on the "bridge mass" and the cost effect based on the increase in the number of blades. The inventors of the present invention have obtained new knowledge about suitable constituent conditions of the vertical axis type hydroelectric power generation device 10 by the invention matters. Based on this finding, the inventors have succeeded in finding out a further optimized configuration condition of the vertical axis type hydroelectric power generation device by proceeding with research based on a new viewpoint. Therefore, next, using FIG. 13 to FIG. 16, another new configuration condition of the vertical axis type hydroelectric power generation device 10 according to the present embodiment will be described.

Here, FIG. 13 is a diagram showing a detailed structure of a single blade according to the present embodiment, where FIG. 13A is a side view of one blade, and FIG. 13B is one blade. The top view of the blade of FIG. In addition, FIG. 14 is a diagram showing a variation state of a load applied when one blade makes one rotation. Further, FIG. 15 is a graph showing the safety factor with respect to the fatigue limit of the stress generated at the corner portion (corner radius portion) of the blade and the output utilization rate. The left vertical axis shows the safety factor against the fatigue limit, and the right vertical axis shows the output utilization rate. Furthermore, FIG. 16 is an enlarged graph of the graph shown in FIG. 15, and shows the case where the safety factor for the fatigue limit on the left vertical axis in FIG. 15 is in the range of 0 to 4. It should be noted that in FIGS. 15 and 16, the ratio of the corner rounded portion 13b shown on the horizontal axis to the blade total length L is one of the upper and lower corner rounded portions 13b included in one blade. It is a ratio calculated based on the dimension R of the radius of curvature of the portion 13b.

By the way, the inventors satisfy the invention matters described with reference to FIGS. 3 to 6, and as shown in FIGS. 7 to 12, the solidity of the water turbine 11 is 0.1 to 0.29. When the constructed vertical axis hydroelectric generator 10 is actually operated in a water flow, the force from the water flow on the blade 13 is very large, and it is again recognized that the blade design considering the blade strength is necessary. In particular, in the vertical axis type hydroelectric generator 10 according to the present embodiment, as shown in FIG. 13, one blade 13 includes a blade straight line portion 13 a formed to extend in the vertical direction and a vertical rotation axis 20. It is composed of a pair of upper and lower blade arm portions 13c extending in the horizontal direction, and a pair of upper and lower corner rounded portions 13b formed at a connecting portion between one blade straight portion 13a and two blade arm portions 13c. There is. That is, the force from the water flow acts on the blade straight portion 13a and the pair of upper and lower corner rounded portions 13b, so that the rotational movement of the water turbine 11 is performed. In this case, it is known that the corner of the single blade 13 where the stress is maximum becomes the corner rounded portion 13b. That is, if the corner rounded portion 13b is small or absent, the strength of the blade 13 will be reduced, and in the worst case, the water turbine 11 will be destroyed. On the other hand, if the corner rounded portion 13b is large, a blade that generates lift will be generated. The length of the straight line portion 13a becomes small, which lowers the power generation efficiency. Therefore, if an optimized blade shape can be proposed from the viewpoint of the strength of the blade 13 and the viewpoint of power generation efficiency, it becomes possible to obtain a more preferable vertical axis type hydroelectric power generation device 10.

Based on the above idea, the inventors conducted research to obtain an optimum blade shape. First, if the number of blades 13 constituting the water turbine 11 is increased within a range in which the solidity of the water turbine 11 is 0.1 to 0.29, the chord length and blade thickness of each blade are reduced. Will be reduced in strength. Here, as shown in FIG. 14, when the water turbine 11 is rotating, a load that changes intricately during one rotation acts on one blade 13 that constitutes the water turbine 11. In particular, it can be seen that the radial load Fn fluctuates significantly during one rotation of the blade 13 as compared to the tangential load Ft. Further, the stress concentration coefficient changes depending on the size of the radius of curvature R of the corner rounded portion 13b. Then, as a result of intensive studies, the inventors calculated the stress amplitude generated in the blade 13 by changing the size of the corner rounded portion 13b in each blade number (2 to 10) by numerical analysis. , The safety factor for fatigue strength was calculated. In this numerical analysis, the material constituting the blade 13 is assumed to be ductile cast iron, alloy, composite resin or the like having excellent strength and manufacturability, and the fatigue strength at the number of repetitions of 10 ⁹ is calculated to be 75 to 180 MPa. It was Further, as described above, when the corner rounded portion 13b is increased, the blade linear portion 13a which is an effective linear portion of the blade 13 is reduced, the performance as a blade is reduced, and the power generation efficiency is reduced. Therefore, the inventors calculated the output utilization rate of the blade 13 that varies depending on the size of the radius of curvature R of the corner radiused portion 13b for each number of blades (2 to 10). The results of these calculations are summarized in FIGS. 15 and 16. In this embodiment, it is assumed that the pair of upper and lower corner rounded portions 13b formed on the blade 13 have the same radius R of curvature. Therefore, the radius of curvature of each of the pair of upper and lower corner rounded portions 13b formed on the blade 13 is “R”, and the ratio of the corner rounded portion 13b shown on the horizontal axis to the blade total length L in FIGS. 15 and 16. As for, the ratio calculated based on the dimension R of the radius of curvature of one of the upper and lower corner rounded portions 13b included in one blade is shown.

From FIG. 15 and FIG. 16, first, the lower limit value of the radius of curvature R of the corner rounded portion 13b is verified. As shown in FIG. 16, regardless of the number of blades from 2 to 10, when the ratio of one corner radiused portion 13b to the total blade length approaches 0%, stress concentration causes a drastic decrease in safety factor. Is clear. Therefore, it can be determined that the ratio of one corner rounded portion 13b to the entire blade length needs to be 1% or more. Therefore, when the radius of curvature of one corner rounded portion 13b is R and the length of the entire blade 13 including the pair of upper and lower corner rounded portions 13b is L, from the viewpoint of ensuring the minimum required safety factor, It can be said that it is necessary to satisfy the inequality (2).
0.01L≦R (2)

Next, the upper limit value of the radius of curvature R of the corner rounded portion 13b is verified. Focusing on the output utilization rate shown on the right vertical axis in FIGS. 15 and 16, the vertical axis type hydroelectric generator 10 according to the present embodiment is a lift-type water turbine 11, and is conventionally used for a small hydroelectric generator. Higher power generation efficiency is required than conventional water turbines of the type such as "Savonius type" that generate power by the drag of water flow. Therefore, regarding the output utilization rate of the vertical axis type hydroelectric generator 10 according to the present embodiment, in consideration of the fact that the water turbine 11 should secure a certain facility capacity, at least a performance with an output utilization rate of 60% or more is secured. There is a need to. When the ratio of one corner rounded portion 13b to the entire blade length when the output utilization rate is 60% is read from the graph of FIG. 16, it can be determined to be 20%. Therefore, when the radius of curvature of one corner rounded portion 13b is R and the length of the entire blade 13 including the pair of upper and lower corner rounded portions 13b is L, it is seen from the viewpoint of the output utilization rate that should be secured at the minimum. In this case, it can be said that the upper limit value of the radius of curvature R of the one corner radius portion 13b needs to satisfy the following inequality (3).
R≦0.20L (3)

Therefore, the condition of the radius of curvature R of one corner radiused portion 13b that satisfies the above two inequalities (2) and (3) can be expressed as the following inequality (4).
0.01L≦R≦0.20L (4)

Note that, in the above verification, as a condition that the output utilization rate of the vertical axis type hydroelectric power generation device 10 that should be ensured at least should be 60% or more, in reality, a higher output utilization rate is required. It is necessary to consider what is required. Therefore, the inventors set an output utilization rate of 70% as a target value for ensuring performance in consideration of economic efficiency and customer requirements. When the ratio of one corner rounded portion 13b to the entire blade length when the output utilization rate is 70% is read from the graph of FIG. 16, it can be determined that it is 15%. Therefore, when the radius of curvature of one corner rounded portion 13b is R and the length of the entire blade 13 including the pair of upper and lower corner rounded portions 13b is L, it is seen from the viewpoint of the output utilization rate that should be secured at the minimum. In this case, it can be said that the upper limit value of the radius of curvature R of the one corner radius portion 13b needs to satisfy the following inequality (5).
R≦0.15L (5)

Therefore, the condition of the radius of curvature R of one corner rounded portion 13b that satisfies the inequalities (2) and (5) can be expressed as the following inequality (6).
0.01L≦R≦0.15L (6)

That is, although the above inequality (4) can be adopted as the condition range that the present invention can take, the vertical axis type that adopts the above condition of the inequality (6) in view of the demand for higher output utilization rate. It can be said that it is more preferable to configure the hydraulic power generation device 10.

As described above, the upper and lower limits of the radius of curvature R of the corner rounded portion 13b have been examined. Next, the inventors examined the number of blades by introducing another viewpoint. In other words, the safety factor for the fatigue limit of the material must be at least 1.25 or higher from the IEC61400-2 regulation, which is a safety standard for wind power generation that has the same design requirements as a turbine. You can A line showing this safety factor of 1.25 is shown in FIGS. 15 and 16. Then, it can be determined that the number of blades satisfying the inequalities (4) and (6) while satisfying the safety factor of 1.25 or more is 6 or less. However, it is also clear from FIG. 16 that when the number of blades is 6, an extremely low safety factor is exhibited when the ratio of one corner rounded portion 13b to the total blade length is less than 10%. is there. Therefore, it can be concluded that the number of blades is preferably 5 or less. In addition, this conclusion pays attention to the invention matter described using FIGS. 3 to 6, that is, the influence of the exciting force (fatigue load) generated on the blade 13 of the water turbine 11 by the thrust force of the water flow, and Overlapping with the number of blades (3 to 5) derived by considering the cost impact of the entire device, which is the sum of the cost impact based on the "mechanical mass" and the "bridge mass" and the cost impact based on the increase in the number of blades. It was a thing, and the certainty of this verification experiment was confirmed again.

The following is a summary of the findings obtained by the research conducted by the inventors described above with reference to FIGS. 3 to 16.

That is, the vertical axis type hydroelectric power generation device according to the present invention is a vertical generator that is rotatably connected to a generator that receives electric power from a water stream to generate electric power and that is vertically hung. A rotary shaft, a vertical axis type hydroelectric power generator comprising a plurality of blades arranged at substantially equal angular intervals along the circumferential direction around the vertical rotary shaft, wherein the plurality of blades are arranged in the vertical direction. It is formed to extend and is formed as a straight blade having a cross-sectional shape of an airfoil shape, and when the plurality of blades is viewed from the bottom side, the blade is composed of five or less blades. To do.

Further, in the vertical axis type hydroelectric power generation device according to the present invention, it is preferable that the plurality of blades is configured with three to five blades when viewed from the bottom surface side.

Further, in the vertical axis type hydroelectric power generation device according to the present invention, the plurality of blades is provided with a corner rounded portion having a curved shape at any one end extending in the vertical direction, and a radius of curvature of the corner rounded portion is When the length of the entire blade including R and the corner radius is L,
0.01L≦R≦0.20L
Can be configured so that

Furthermore, in the vertical axis type hydroelectric generator according to the present invention, the inequality is
0.01L≦R≦0.15L
Can be configured to be

Furthermore, in the vertical-axis hydroelectric generator according to the present invention, the blade has two corner rounded portions each having a curved shape at each of the upper and lower end portions extending in the vertical direction, and the two corner rounded portions are provided. It can be assumed that they are formed with the same size.

Furthermore, the vertical axis type hydroelectric power generation device according to the present invention can be configured such that the solidity of the plurality of blades is 0.1 to 0.29.

Although the preferred embodiment of the present invention has been described above, the technical scope of the present invention is not limited to the scope described in the above embodiment. Various changes or improvements can be added to the above-described embodiment.

For example, in the above-described embodiment, the plurality of blades 13 installed around the vertical rotation shaft 20 are each configured as a straight blade formed by extending over the entire length of the water turbine 11 in the vertical direction. However, the plurality of blades according to the present invention is formed as a straight blade formed to extend in the vertical direction and the cross-sectional shape is a wing shape, and, when viewed from the bottom surface side, the plurality of blades, Any blade can be used as long as it is composed of 5 or less blades. In other words, for example, the length of the blade may be set to about half the length of the water turbine 11 in the vertical direction, and two-stage upper and lower blades may be provided. However, it goes without saying that the plurality of blades need to be configured to have five or less blades when viewed from the bottom side.

Further, for example, in FIGS. 14 to 16 which describe the present embodiment, the dimension of the curvature radius R of each of the pair of upper and lower corner rounded portions 13b formed on the blade 13 is described as the same value in the upper and lower sides. However, the scope of the present invention is not limited to the scope of this embodiment described above. That is, in the blade of the present invention, the radius of curvature R of each of the corner rounded portions may be different at the upper and lower sides of the blade depending on the installation environment of the vertical axis type hydroelectric generator. For example, when the flow velocity on the water surface side of the water channel is high and the flow velocity on the bottom surface side of the water channel is low due to resistance with the water channel bottom surface, the dimension of the radius of curvature R of the upper corner rounded portion is increased to improve the strength of the upper side of the blade. It is possible to adopt a configuration in which the size of the radius of curvature R of the lower corner rounded portion of the blade is made smaller than that of the upper side thereof. Note that the installation environment of such a vertical axis type hydroelectric generator may change depending on the installation environment such as the material of the water channel (for example, whether it is concrete or soil) or the surface condition in the water channel. It is known, and the dimensional condition of the corner rounded portion may be determined according to the installation environment.

It is apparent from the description of the scope of claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

10 vertical axis type hydroelectric generator, 11 turbine, 13 blade, 13a blade straight part, 13b corner radius part, 13c blade arm part, 20 vertical rotating shaft, 30 bearing support part, 50 generator, 60 support, 61 bridge part , 62 Foundation, 100 Vertical Axis Hydroelectric Unit.

Claims (6)

A generator that generates electric power by receiving the rotational driving force from the water flow,
A vertically rotating shaft that is rotatably connected to the generator and that is hung vertically.
A plurality of blades arranged at substantially equal angular intervals along the circumferential direction around the vertical rotation axis,
A vertical axis type hydroelectric generator comprising:
The plurality of blades are formed as straight blades that extend linearly in the vertical direction and have a cross-sectional shape of a blade shape, and when the plurality of blades are viewed from the bottom surface side, five blades are formed. It consists of the following number of blades ,
The plurality of blades is provided with a corner radius portion having a curved shape at one of the end portions extending in the vertical direction,
The radius of curvature of the corner radius portion is R,
The entire length of the blade including the corner radius portion is L,
And when
0.01L≦R≦0.20L
Is constructed so that the inequality
The vertical axis hydroelectric power generating device , wherein each of the plurality of blades is configured to have an outer shape of a substantially U shape . The vertical axis hydroelectric generator according to claim 1,
A vertical axis type hydroelectric power generation device, characterized in that the plurality of blades are composed of three to five blades when viewed from the bottom side. The vertical axis hydroelectric generator according to claim 1 or 2 ,
Where the inequality is
0.01L≦R≦0.15L
A vertical axis type hydroelectric power generation device, characterized in that In the vertical axis type hydroelectric generator according to any one of claims 1 to 5 ,
The blade is provided with two corner rounded portions each having a curved shape at each of upper and lower end portions extending in the vertical direction, and the two corner rounded portions are formed to have the same size. Axial hydroelectric generator. In the vertical axis type hydroelectric power generator according to any one of claims 1 to 5 ,
The vertical axis type hydroelectric power generation device, wherein the solidity of the plurality of blades is configured to be 0.1 to 0.29. A vertical axis type hydroelectric power generator according to any one of claims 1 to 5 ,
A support body that supports the fixed axis type hydroelectric power generator during fixed installation;
A bridge portion connected to the support,
Have
The vertical axis type hydroelectric power generation unit, wherein the bridge section is fixedly installed on a foundation section provided at an installation location.

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