Power generation system and power generation method

Abstract

To provide a power generation system and a power generation method that can convert the kinetic energy at the time of discharging sediment deposited in a dam reservoir into electric energy and effectively utilize the energy at the time of sediment discharge.SOLUTION: A system 20 for generating electricity using sediment S deposited on a water bottom comprises: a sand discharge path 21 for discharging the sediment S deposited on the water bottom to an opposite side to the water bottom with an embankment body 7 interposed between them as a sand discharge flow S1; and a power generation device 22 provided in the sand discharge path 21 and converting the kinetic energy of the sand discharge flow S1 into electrical energy.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a power generation system and a power generation method.

Background Art

[0002] Conventionally, dams for power generation, flood control (flood regulation), irrigation, water supply, industrial use, etc. form a reservoir (a water storage area including a water storage lake) in the upper reaches of the dam by blocking the river flow path with a dam body. As a result, sediment such as sand accumulates on the bottom of the reservoir.

[0003] Sediments such as sand, gravel, stones (rocks), and driftwood deposited on the bottom, so-called "sand deposits", cause a decrease in the water storage capacity of the dam. Also, since they gradually develop upstream from near the dam body, they cause a rise in the water level in the upper reaches during floods and can be a factor in waterlogging damage and the like. In recent years, in many dams, the amount of sand deposits generated due to heavy rainfall and the like frequently occurring due to abnormal weather has a tendency to increase compared to the plan at the time of dam construction.

[0004] On the other hand, if the supply of sediment from upstream to downstream is completely blocked by a dam, many adverse effects will occur, such as scouring of the riverbed in the downstream area of the dam, recession of the coastline, disappearance of sandy beaches, collapse of revetments, changes in ocean currents and river flows, increase in flood damage, and impact on the ecosystem.

[0005] Therefore, it is important to discharge a certain amount of sand deposits in the upper reaches of the dam to the lower reaches of the dam. As such sediment discharge methods, many techniques have been proposed and put into practical use (for example, see Patent Document 1). For example, a method of dredging sand deposits using a dredger equipped with a grab bucket, a backhoe, a pump, etc., and transporting and discharging them from the upper reaches of the dam to the lower reaches of the dam, or a method of providing a sediment discharge path by penetrating or bypassing the dam body, and further providing a sediment discharge gate in the sediment discharge path, and discharging the sand deposits to the lower reaches of the dam through the sediment discharge path as appropriate when they have accumulated to a certain thickness and height, etc. have been put into practical use.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] Here, in a power generation dam, as is well known, water in a reservoir impounded by a dam body is taken in from a water intake and sent and discharged to the downstream area of the dam by natural flow using the water head difference (potential energy), and a turbine is rotationally driven using the kinetic energy during this water sending and discharging to generate electricity.

[0008] On the other hand, in the case of sediment accumulation, it is difficult to make it flow naturally easily, at a large flow rate, and at a large flow velocity like water because it accumulates on the bottom of the reservoir and has a small potential energy. Furthermore, the frequency of sediment flushing is generally low, at most every few months, usually every few years, and in some cases every few decades, due to the progress of sediment accumulation. For this reason, there is little idea of effectively using the kinetic energy during sediment flushing and discharging, and currently, the potential energy of sediment flushing that requires a great deal of labor and costs such as a great deal of equipment is wasted without being used.

[0009] In view of the above circumstances, an object of the present disclosure is to provide a power generation system and a power generation method that can convert the kinetic energy during sediment flushing of sediment accumulated in a dam reservoir into electrical energy and effectively utilize the energy during sediment flushing.

Means for Solving the Problems

[0010] (1) One aspect of the power generation system of the present disclosure is a power generation system for generating electricity using sediment accumulated on the bottom of a dam reservoir, comprising a sediment flushing channel for discharging the sediment accumulated on the bottom as a sediment flushing flow to the downstream side of the dam body, and a power generation device provided in the sediment flushing channel for converting the kinetic energy of the sediment flushing flow into electrical energy.

[0011] In this case, by utilizing the force (scouring force) that transports sediment such as sand in the water stored in the reservoir, the accumulated sediment is discharged as a sediment-laden flow together with the stored water through a sediment discharge channel, and the kinetic energy of the sediment-laden flow can be converted into electrical energy by a power generation device provided in the sediment discharge channel.

[0012] At this time, even if the potential energy of the accumulated sediment is small, the mass of the accumulated sediment and thus the sediment-laden flow is larger than that of water. As a result, the kinetic energy of the sediment-laden flow is large. Therefore, even when using accumulated sediment with low potential energy, it is possible to ensure power generation efficiency equivalent to or even higher than that of hydroelectric power generation in some cases.

[0013] Therefore, according to one aspect of the power generation system of the present disclosure, it becomes possible to effectively utilize the kinetic energy (potential energy of the accumulated sediment) during sediment discharge of the accumulated sediment that was simply discharged downstream of the dam and wasted, and generate electricity. In addition, by using hydroelectric power generation and power generation using dam sediment in combination, the value of dams for hydroelectric power generation and multi-purpose dams can be enhanced.

[0014] (2) Another aspect of the power generation system of the present disclosure is that, in the above (1), the power generation device includes an impact power generation plate for colliding the sediment-laden flow and converting the impact energy into power generation energy.

[0015] In this case, it becomes possible to realize power generation using the accumulated sediment simply by guiding the sediment-laden flow so as to collide with the impact power generation plate. Thereby, it is possible to generate electricity using the accumulated sediment without incurring high costs, the cost-effectiveness is very high, and the applicability of the power generation system can be significantly enhanced.

[0016] (3) Another aspect of the power generation system of the present disclosure is that, in the above (2), the sediment discharge channel includes a sediment discharge pipe penetrating the dam body, and a diversion wall provided on the front surface of the dam body to form a sand discharge path for guiding the sediment-laden flow discharged from the discharge port of the sediment discharge pipe to the downstream side of the dam body, and the impact power generation plate is attached to at least a part of the wall surface of the diversion wall.

[0017] In this case, by simply installing the impact power generation plates on the wall surface of the diversion wall of the existing sediment discharge facility of the dam, it becomes possible to easily realize power generation using the sediment accumulation. As a result, the cost-effectiveness can be further enhanced, and the applicability of the power generation system using the dam sediment accumulation can be further improved.

[0018] (4) Another aspect of the power generation system of the present disclosure is, in the above (1), the power generation device includes a turbine device that receives the sediment discharge flow and rotates around an axis, and a power generation device main body that generates power by the rotation of the turbine device.

[0019] In this case, similar to hydraulic power generation, the turbine device can be rotated by the kinetic energy of the sediment discharge flow, and the rotational energy of this turbine device can be converted into electrical energy by the power generation device main body to generate power.

[0020] (5) Another aspect of the power generation system of the present disclosure is, in the above (4), the power generation device is a crusher.

[0021] In this case, for example, a crusher including a rotating shaft that rotates around an axis by an electric motor, a blade that is coaxially connected to the rotating shaft and has a rotating blade (crushing blade) for crushing an object to be crushed such as a rock as it rotates, and a sturdy housing that houses the rotating shaft and the blade and has an inlet for receiving the object to be crushed and an outlet for discharging the processed material after crushing along with the rotation of the blade is applied as the power generation device.

[0022] Specifically, for example, the inlet of the crusher is made to be the outlet and the outlet is made to be the inlet, and the sediment discharge flow is introduced into the housing from the inlet corresponding to the outlet of the crusher, and this is received by the turbine blades corresponding to the blades and the rotating blades (crushing blades), and the rotating shaft, and thus the power generation device main body corresponding to the electric motor of the crusher is rotationally driven to generate power.

[0023] This makes it unnecessary to newly research and develop a power generation device that has sufficient durability against the sand discharge flow from scratch. Also, when discharging the accumulated sand, by diverting / redirecting the crusher of the crushing equipment that is pre-equipped as a dam facility, or by simply preparing a power generation device with specifications substantially equivalent to that of a crusher, a power generation device for dam accumulated sand and thus a power generation system can be realized.

[0024] (6) Another aspect of the power generation system of the present disclosure is, in the above (1), the power generation device includes an endless belt that travels receiving the sand discharge flow, a rotating body that rotates by the travel of the endless belt, and a power generation device main body that generates electricity by the rotation of the rotating body.

[0025] In this case, the kinetic energy of the sand discharge flow can be used to run the endless belt and rotate the rotating body, and the rotational energy of the rotating body can be converted into electrical energy by the power generation device main body to generate electricity.

[0026] (7) Another aspect of the power generation system of the present disclosure is, in any one of the above (4) to (6), the power generation device is arranged on the downstream side of the dam body.

[0027] In this case, for example, when installing a power generation system using dam accumulated sand in an existing dam, the modification work on the existing dam, such as providing a sand discharge path in the existing dam body, is relatively less. Therefore, for example, it is relatively easy to install a power generation system using dam accumulated sand in an existing dam.

[0028] (8) Another aspect of the power generation system of the present disclosure is, in any one of the above (4) to (6), at least a part of the power generation device is arranged inside the dam body.

[0029] In this case, it is relatively easy to secure an installation space for the power generation device.

[0030] (9)One aspect of the power generation method of the present disclosure is a power generation method for generating power by the above-described power generation system, including a sand deposit stirring step of loosening the sand deposit deposited on the bottom of the water at the bottom of the water, a sand discharge step of discharging the loosened sand deposit in the sand deposit stirring step as the sand discharge flow together with the stored water through the sand discharge path, and a power generation step of converting the kinetic energy of the sand discharge flow into electrical energy by the power generation device.

[0031] In this case, the operational effects of the above-described power generation system can be obtained.

[0032] Furthermore, by providing a sand deposit stirring step of loosening the sand deposit deposited on the bottom of the water, it is possible to utilize the water pressure of the water stored in the storage pond and the force of the water flow (sweeping force) to suitably discharge a wide range of sand deposits as a sand discharge flow. For this reason, for example, it is possible to eliminate the dam operation steps during sand discharge, such as the lowering of the water level in the storage pond and the recovery of the water level in the storage pond, which require a great deal of time and labor for observation and management over time. It becomes possible to efficiently and effectively discharge sand and generate power with the sand discharge flow. Therefore, it becomes possible to achieve even more remarkable operational effects.

Effects of the Invention

[0033] According to the power generation system and power generation method of the present disclosure, it is possible to convert the kinetic energy when discharging the sand deposit deposited in the dam storage pond into electrical energy and effectively utilize the energy during sand discharge.

Brief Description of the Drawings

[0034]

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Embodiments for Carrying Out the Invention

[0035] (First Embodiment) Hereinafter, with reference to FIGS. 1 to 6, a power generation system using dam sediment and a power generation method using dam sediment according to an embodiment will be described.

[0036] First, as shown in FIGS. 1, 2, and 3, the dam 1 of the present embodiment is, for example, a multipurpose dam or the like, and includes a hydroelectric power generation facility 2, a water discharge facility 3, and a sand discharge facility 4 which is a component of the power generation system using the dam sediment of the present embodiment. Here, "sand discharge" means discharging sediment and the like deposited on the bottom (floor) 6 of the dam reservoir 5. However, "sand discharge" in the present disclosure includes so-called "sand passage" that allows sediment and the like flowing into the dam reservoir 5 to pass through. Further, "sand discharge" in the present disclosure includes not only soil and sand but also gravel, stones (rocks), driftwood, and the like.

[0037] As shown in FIGS. 1 and 2, the hydroelectric power generation facility 2 includes, for example, a water intake 8 for taking in the water W in the reservoir 5 of the upper dam area R1 blocked by the dam body 7 of the dam 1, a water conduit 9 for sending the water W taken in at the water intake 8, a water conduit gate 10 for opening and closing the water conduit 9, a waterwheel (runner) 11 rotated by the kinetic energy of the water W conducted through the water conduit 9, a generator 12 for converting the rotational energy of the waterwheel 11 into electric energy, a transformer 13 for boosting the electric power generated by the generator 12, power transmission equipment 14 such as electric wires and high-voltage iron towers for transmitting the electric power boosted by the transformer 13, and a water discharge channel 15 for discharging the water W that has rotated the waterwheel 11 to the lower dam area R2.

[0038] The configuration of the water conduit 9 is not particularly limited as long as it can send the water W in the upper dam area R1 to the lower dam area R2 and allow it to flow down naturally at a desired head. For example, the water conduit 9 is appropriately and selectively configured to include a water conduit 16 that penetrates the dam body 7 from the front surface 7a to the back surface 7b and extends to the lower dam area R2 from the front surface 7a, or a water conduit that straddles the top (crest) 7c of the dam body 7 and extends to the lower dam area R2, or a water conduit that bypasses the dam body 7 and extends to the lower dam area R2, or a water conduit (water conduction tunnel) that extends to the lower dam area R2 through the ground G below the dam body 7.

[0039] As shown in FIGS. 1, 2, and 3, the water discharge facility 3 is provided with a discharge channel 17 for discharging the water W in the upper dam basin R1 through the back surface 7b on the upper dam basin R1 side of the dam body 7 to the front surface 7a on the lower dam basin R2 side. As the discharge channel 17, an emergency flood discharge (surplus water discharge) provided on the crest 7c side, a normal flood discharge provided on the lower part side of the dam body with a conzzit gate, and an emergency flood discharge provided in the middle part of the dam body with an orifice gate are appropriately and selectively provided. Further, the discharge channel 17 is provided with a diversion wall 18 for diverting the water W discharged from the outlet of the flood discharge and a flow reduction structure 19 for reducing the momentum of the discharged water W, etc.

[0040] (Power generation system using dam sediment) As shown in FIGS. 1, 2, 3, and 4, the sediment removal facility 4 is provided with a power generation system 20 using dam sediment for generating power using the sediment S deposited on the bottom 6 of the dam reservoir 5.

[0041] The power generation system 20 using dam sediment in this embodiment includes a sediment discharge channel 21 for discharging the sediment S deposited on the bottom 6 of the dam reservoir 5 as a sediment discharge flow S1 to the downstream side (R2) of the dam body 7, and a power generation device 22 provided in the sediment discharge channel 21 for converting the kinetic energy of the sediment discharge flow S1 into electrical energy. Note that the sediment S also includes sediment such as earth and sand flowing into the dam reservoir 5.

[0042] The sediment discharge channel 21 in this embodiment is provided on the lower part side of the dam body 7, for example, penetrating from the back surface 7b to the front surface 7a of the dam body 7, and includes a sediment discharge pipe (sediment discharge outlet) 21a for sending the sediment S in the upper dam basin R1 to the lower dam basin R2, and a sand discharge channel 21c for guiding the sediment discharge flow S1 including the water W and the sediment S discharged from the discharge port 21b of the sediment discharge pipe 21a to the lower dam basin R2.

[0043] Further, in this embodiment, the sand discharge channel 21c is formed with a diversion wall 21d.

[0044] In the power generation system 20 using dam sediment in this embodiment, a power generation device 22 for sediment power generation that converts the kinetic energy of the sediment flow S1 into electrical energy is provided in the sediment discharge channel 21c. This power generation device 22 is configured to include a vibration power generation device (impact power generation plate) 23 for converting the fluid energy of the sediment flow S1 into power generation energy.

[0045] Note that the power generation device 22 for sediment power generation is equipped with a transformer 13 for boosting the power generated by the vibration power generation device 23, and power transmission facilities 14 such as electric wires and high-voltage iron towers for transmitting the power boosted by the transformer 13. Of course, these transformer 13 and power transmission facilities 14 may be provided in a form that can be shared with the hydraulic power generation facility 2.

[0046] Also, the power generated by the power generation system 20 using dam sediment in this embodiment may be configured such that the equipment is used within the dam facility.

[0047] Furthermore, the sediment discharge pipe 21a for sending the sediment S in the upper dam area R1 to the lower dam area R2 does not necessarily have to be limited to the sediment discharge pipe 21a that penetrates the dam body 7. It may be a sediment discharge pipe that straddles the dam top 7c and extends to the lower dam area R2 for sending the sediment S in the upper dam area R1 to the lower dam area R2, a sediment discharge pipe that bypasses the dam body 7 and extends to the lower dam area R2, a sediment discharge pipe that extends to the lower dam area R2 through the ground G below the dam body 7, etc., and these may be selectively provided as appropriate.

[0048] The vibration power generation device 23 does not particularly need to be limited in its configuration as long as it can convert the fluid energy of the sediment flow S1 into power generation energy. In other words, as long as it can create energy from the vibration generated by the sediment flow S1.

[0049] On the other hand, the vibration power generation device 23 in this embodiment is, for example, an impact power generation plate 24 attached to the wall surface of the flow guiding wall 21d that forms the sediment discharge channel 21c. It collides with the sediment flow S1 and converts the impact energy (the fluid energy and vibration energy of the sediment flow S1) into power generation energy.

[0050] Examples of the impact power generation plate 24 include piezoelectric types using piezoelectric elements that generate voltage when a force is applied, magnetic types that generate voltage when a force is applied and the coil and magnet move relative to each other, permanent charge types that generate voltage when a force is applied and the electrode plate adsorbed with charges moves, and magnetostrictive types that are known for the representative research and development by the Vibration Power Generation Laboratory, Department of Electronic Information and Communication Engineering, School of Science and Engineering, Kanazawa University, and generate voltage due to a large change in magnetization (magnetic flux lines) when a force is applied and the magnetostrictive effect (inverse magnetostrictive effect). Such vibration power generation devices are given as examples.

[0051] (Power generation method using dam sediment) When generating power using the power generation system 20 using dam sediment of the present embodiment (in the power generation method using dam sediment of the present embodiment), first, as shown in FIG. 5, the sediment S deposited on the bottom 6 of the dam reservoir 5 is loosened at the bottom 6 (sediment stirring step).

[0052] Here, "loosening the sediment S" in the present disclosure means reducing the bearing capacity of the solidified sediment layer and making the sediment S removable as the sediment flow S1 in the sediment discharge path 21 using the force of the water flow (scouring force) in the subsequent sediment discharge step. For this reason, in the sediment stirring step, any means such as drilling holes and stirring in the sediment layer or applying vibration to collapse it are applicable as long as the bearing capacity of the sediment layer can be reduced.

[0053] More specific operations for loosening the sediment S (sediment stirring step) include, for example, mounting work machines such as an earth drill 27, ground improvement, and deep mechanical stirrers for pile driving on floating bodies such as pontoons 25 and dredgers, or fixed scaffolds installed and constructed at predetermined positions of the reservoir 5, dredging work machines such as grab buckets and backhoes, and work machines with similar configurations or uses to these work machines, and using these work machines to stir, drill holes in, or collapse the sediment S (sediment layer) on the bottom 6.

[0054] Then, as shown in FIGS. 3, 4, and 5 (FIG. 1), the sand discharge gate 26 is opened, and using the water pressure of the water W stored in the water storage tank 5 and the sweeping force of the flow of the water W that transports sediment such as soil, the accumulated sand S loosened in the accumulated sand stirring process is discharged together with the stored water W as a sand discharge flow S1 through the sand discharge channel 21, and the sand discharge flow S1 is discharged into the sand discharge channel 21c (sand discharge process). At the same time, the kinetic energy of the sand discharge flow S1 flowing through the sand discharge channel 21c is converted into electrical energy by the vibration power generation device 23 (impact power generation plate 24) (power generation process).

[0055] Therefore, according to the power generation system 20 using dam accumulated sand and the power generation method using dam accumulated sand of the present embodiment, it is possible to effectively utilize the kinetic energy (potential energy of the accumulated sand S) during sand discharge of the accumulated sand S that was simply discharged into the downstream area R2 of the dam and wasted, and perform power generation.

[0056] In addition, hydropower and power generation using dam accumulated sand can be used in combination, and the value of the dam 1 for hydropower can be increased.

[0057] Here, conventionally, in the case of the accumulated sand S, the main reasons are that it accumulates on the bottom 6 of the water storage tank 5 and has a small potential energy, and it cannot flow naturally easily and at a large flow rate and large flow velocity like the water W, so the kinetic energy during sand discharge has not been utilized.

[0058] However, the density of sand (accumulated sand S) is, for example, 2 to 3 (ton / m3) with respect to the density of water W: 1 (ton / m3), and the density of the sand discharge flow S1 including the accumulated sand S and water W is also much larger compared to water W. Also, when the mass is m (kg) and the velocity is v (m / s), the kinetic energy K can be expressed as K = 1 / 2 × m × v2.

[0059] As a result, in hydropower, kinetic energy is secured by the potential energy of water W, whereas in the power generation using the accumulated sand S of the present embodiment, even if the potential energy is small, kinetic energy can be secured by the mass of the accumulated sand S and thus the sand discharge flow S1. Therefore, in the power generation system 20 using dam sediment and the power generation using dam sediment according to the present embodiment, even when using sediment S with low potential energy, for example, kinetic energy equivalent to that of hydroelectric power can be ensured, and power generation efficiency equivalent to that of hydroelectric power can be ensured.

[0060] Further, in the power generation system 20 using dam sediment according to the present embodiment, the power generation device 22 is configured to include an impact power generation plate 24 for colliding with the sediment flow S1 and converting impact energy into electric energy. For this reason, it becomes possible to realize power generation using sediment S only by guiding the sediment flow S1 so as to collide with the impact power generation plate 24.

[0061] Furthermore, in the power generation system 20 using dam sediment according to the present embodiment, the sediment discharge passage 21 includes a sediment discharge pipe 21a that penetrates the dam body 7, and a diversion wall 21d that is provided on the front surface 7a of the dam body 7 and forms a sand discharge passage 21c for guiding the sediment flow S1 discharged from the discharge port 21b of the sediment discharge pipe 21a to the downstream side R2 of the dam body 7, and the impact power generation plate 24 is attached to at least a part of the wall surface of the diversion wall 21d. Thereby, it becomes possible to easily realize power generation using sediment S only by installing the impact power generation plate 24 on the wall surface of the diversion wall 21d of the existing sediment discharge facility 4 of the dam 1. In other words, power generation can be performed using sediment S without incurring a large cost, the cost-effectiveness is very high, and the applicability of the power generation system 20 using dam sediment can be significantly enhanced.

[0062] Furthermore, usually, when discharging (draining) the dam sediment S, it is necessary to perform five dam operation steps (steps): (a) measures during water discharge, (b) lowering the water level of the storage pond 5, (c) natural flow of the sediment S, (d) restoring the water level of the storage pond 5, and (e) measures after sediment discharge, step by step. In contrast, in the power generation method using dam sediment according to the present embodiment, the sediment S is loosened in advance, and the sediment is discharged by utilizing the water pressure of the stored water W stored in the water storage tank 5 and the scouring force of the flow of the water W. Therefore, it is possible to eliminate the two dam operation steps of the conventional (b) lowering of the water level in the water storage tank 5 and (d) recovery of the water level in the water storage tank 5, which require a great deal of time and labor for observation and management over time. It becomes possible to efficiently and effectively discharge the sediment and generate power with the sediment discharge flow S1. Therefore, it becomes possible to achieve an even more remarkable effect. Note that, in the power generation method using dam sediment according to the present embodiment, of course, the dam operation steps of (b) lowering the water level in the water storage tank 5 and (d) recovering the water level in the water storage tank 5 may be performed.

[0063] In addition, by loosening the sediment S in advance, the influence range of the scouring force on the sediment S, and thus the sediment dischargeable range, can be significantly expanded. Therefore, by simply performing one step (one effort) of loosening the sediment S in advance, it becomes possible to significantly increase the sediment discharge efficiency and thus the power generation efficiency.

[0064] Here, in the power generation system 20 using dam sediment and the power generation method using dam sediment according to the present embodiment, for example, as shown in Table 1, considering the season (time), sediment situation, water storage level, scouring force, sediment stirring effect, etc., it is preferable to determine the implementation time of each step so that power generation using sediment discharge and sediment can be suitably performed.

[0065]

Table 1

[0066] (Second Embodiment) Next, with reference to FIGS. 7, 8, 9 (and FIGS. 1, 2, 5, 6), a power generation system using dam sediment and a power generation method using dam sediment according to the second embodiment will be described. Here, in the present embodiment, a part of the configuration of the sediment discharge facility 4 is different from that of the first embodiment. Therefore, for the same configuration as that of the first embodiment, the same reference numerals are used and the detailed description thereof is omitted.

[0067] (Power generation system using dam sediment) The sediment discharge facility 4 of this embodiment, similar to the first embodiment, includes a power generation system 20 using dam sediment for generating power by using the sediment S deposited on the bottom 6 of the dam reservoir 5.

[0068] Also, as shown in FIG. 7, the power generation system 20 using dam sediment of this embodiment includes a sediment discharge channel 21 for discharging the sediment S deposited on the bottom 6 of the dam reservoir 5 as a sediment discharge flow S1 to the downstream side R2 of the dam body 7, and a power generation device 22 provided in the sediment discharge channel 21 for converting the kinetic energy of the sediment discharge flow S1 into electrical energy.

[0069] On the other hand, the sediment discharge channel 21 of this embodiment is provided, for example, penetrating from the back surface 7b to the front surface 7a of the dam body 7 on the lower side of the dam body 7, and includes a sediment discharge pipe (sediment discharge outlet) 21a for sending the sediment S in the upper dam area R1 to the lower dam area R2, and the discharge port 21b of this sediment discharge pipe 21a is connected to the power generation device 22.

[0070] Note that the sediment discharge pipe 21a for sending the sediment S in the upper dam area R1 to the lower dam area R2 does not necessarily have to be a sediment discharge pipe penetrating the dam body 7, as long as it is possible to send the sediment S in the upper dam area R1 to the lower dam area R2 and further to the power generation device 22. For example, it may be a sediment discharge pipe straddling the top 7c of the dam body 7 and extending to the lower dam area R2, a sediment discharge pipe extending around the dam body 7 to the lower dam area R2, a sediment discharge pipe extending through the ground G below the dam body 7 to the lower dam area R2, etc. Also, the sediment discharge pipe may be laid so as to send the dredged sediment S to the power generation device 22. Furthermore, these sediment discharge pipes may be selectively configured as appropriate.

[0071] Next, the power generation device 22 of this embodiment includes an impeller device 30 having an impeller 30a that rotates around an axis upon receiving the sediment discharge flow S1, and a power generation device main body 31 that generates power by the rotation of the impeller device 30. Similar to the hydroelectric power generation facility 2, the power generation device main body 31 can apply a generator that generates power by the rotation of the impeller device 30.

[0072] On the one hand, since the fluid that rotates the turbine device 30 is not water W but a sand and gravel flow S1 that contains, in some cases, rocks with a diameter of, for example, 20 to 30 cm, there is a risk of damage, breakage, wear, etc. occurring in the same member configuration as the hydraulic power generation facility 2, that is, there may be a problem with durability.

[0073] Therefore, it is necessary to configure the power generation device 22 of the present embodiment using robust members, particularly for the turbine device 30 and the housing that takes in the sand and gravel flow S1 into the power generation device 22. However, newly researching and developing from scratch a power generation device 22 that has sufficient durability against the sand and gravel flow S1 requires a great deal of labor and cost.

[0074] In contrast, as shown in FIG. 8, the inventor of the present application has continuously conducted intensive research as a dam engineer regarding the application of a crusher 40 including a rotating shaft 32 that rotates around the axis O1 by an electric motor, a blade 34 that is coaxially connected to the rotating shaft 32 and has a rotating blade (crushing blade) 33 for crushing a crushing object M1 such as a rock as it rotates, a collision plate 35 that collides with the crushing object M1 and crushes it together with the rotating blade 33, and a robust housing 38 that houses the rotating shaft 32, the blade 34, and the collision plate 35 and has an inlet 36 for receiving the crushing object M1 and an outlet 37 for discharging the processed object M2 after crushing as the blade 34 rotates, and has found that the application is sufficiently possible and beneficial for the power generation system 20 using dam sediment.

[0075] Specifically, first, in a dam 1 such as a multipurpose dam, for example, due to heavy rain, typhoons, etc., and also due to the resulting water spouts, debris flows, etc., there are many cases where rocks M1 flow down from the upper reaches of the river into the dam reservoir 5. And, for example, during the water level reduction or drought of the reservoir 5, the rocks M1 are recovered by sand removal or dredging, and the recovered rocks M1 are crushed by the crusher 40 and used as aggregates for other construction works.

[0076] Also, during dam construction, crushing equipment including the crusher 40 is provided to secure concrete aggregates and is removed when the dam construction is completed. Furthermore, the local aggregate plant is equipped with the crusher 40. Therefore, dam engineers already have accumulated knowledge and information regarding the specifications of the crusher 40 suitable for the sediment S flowing into the reservoir 5.

[0077] Focusing on this point, the inventor of the present application has invented a power generation system 20 and a power generation method using dam sediment in this embodiment, in which, at the time of discharging sediment S, which occurs at most every few months, usually every few years, and in some cases every few decades, the crusher 40 of the crushing equipment is diverted (reused), or a power generation device having specifications substantially equivalent to those of the crusher 40 is newly prepared, and the kinetic energy of the sediment flow S1 is converted into electrical energy.

[0078] The power generation device 41 that diverts the crusher 40 of the crushing equipment or the power generation device 41 having specifications substantially equivalent to those of the crusher 40 is configured such that, for example, as shown in FIG. 9, generally, the inlet 36 of the crusher 40 shown in FIG. 8 becomes the discharge port 42 and the discharge port 37 becomes the inlet 43 (a configuration similar to that of the crusher 40). When the sediment flow S1 is introduced into the housing 44 through the sediment discharge pipe 21a from the inlet 43 corresponding to the discharge port 37 of the crusher 40, it is received by the impeller 46 of the impeller device 45 corresponding to the blade 34 and the crushing blade (rotating blade) 33, and the rotating shaft 47 (32), and thus the power generation device main body (not shown) corresponding to the electric motor of the crusher 40 is rotationally driven to generate electricity.

[0079] It is preferable to control the rotational speed of the impeller device 45 with a speed regulator so as to keep it as constant as possible, so that electricity with a stable frequency can be generated.

[0080] The power generation device main body (not shown) mainly includes, for example, an armature (amateur) having windings, a stator (stator) having magnets and yokes, a rotating shaft (shaft) connected to the armature, bearings and a commutator, and terminals (terminals) for extracting electric power. Such a power generation device main body is a generator, and the impeller 46 and the rotating shaft 47 are connected to the rotating shaft or the armature, and are configured to convert the rotational energy of these impeller 46 and rotating shaft 47 into electrical energy.

[0081] After rotating the impeller device 45, the sand discharge flow S1 is discharged from the discharge port 42 corresponding to the inlet 36 of the crusher 40 and released into the downstream area R2 of the dam.

[0082] (Power generation method using dam sediment) Also, when generating electricity using the kinetic energy of the sand discharge flow S1 by using the power generation system 20 using dam sediment of this embodiment (in the power generation method using dam sediment of this embodiment), similar to the first embodiment, first, the sediment S deposited on the bottom 6 of the dam reservoir 5 is loosened at the bottom 6 (sediment stirring step: see Fig. 5).

[0083] Then, the sediment gate 26 is opened, and using the water pressure of the water W stored in the reservoir 5 and the scouring force of the flow of the water W to carry sediment and the like, the sediment S loosened in the sediment stirring step is discharged together with the stored water W as the sand discharge flow S1 through the sand discharge pipe 21a (sand discharge step). Further, the sand discharge flow S1 sent from the sand discharge pipe 21a is received by the power generation device main body (generator) of the power generation device 22, the impeller device 45 is rotated by the kinetic energy of this sand discharge flow S1 to generate electricity, and the sand discharge flow S1 is discharged into the downstream area R2 of the dam (power generation step: see Fig. 6).

[0084] Here, for example, by supplying power from the outside to the power generation device main body, it is preferable that the power generation device main body is configured so that the power generation device main body 31 or the power generation device main body (not shown) of the power generation device 41 can function as an electric motor. Then, in the sand discharge step, by supplying power from the outside to the power generation device main body to drive the power generation device main body, the impeller devices 30 and 45 may be rotated. That is, in the power generation system using dam sediment according to the second embodiment, it is preferable that the power generation device 22 is configured to be able to convert electrical energy into the kinetic energy of the sand discharge flow S1 by receiving power supply. Hereinafter, regarding supplying power from the outside to the power generation device main body to drive the power generation device main body in the sand discharge step, it will be described with reference to Figs. 10A, 10B, and 10C.

[0085] FIG. 10A is a diagram schematically showing the power generation system 20 immediately before opening the sand discharge gate 26 in the sand discharge process of the power generation method using dam sediment in the present embodiment. FIG. 10B is a diagram schematically showing the power generation system 20 when the sand discharge flow S1 starts to flow in the sand discharge process of the power generation method using dam sediment in the present embodiment. FIG. 10C is a diagram schematically showing the power generation system 20 when the sand discharge flow S1 starts to be discharged into the downstream area R2 of the dam in the sand discharge process of the power generation method using dam sediment in the present embodiment.

[0086] In FIGS. 10A, 10B, and 10C, when there is almost no sediment S in the sediment discharge path 21 on the downstream side of the sediment discharge gate 26 before the start of the sediment discharge process, that is, when the water W in the storage pond 5 has washed away the sediment S in the sediment discharge path 21 in the previous power generation process, or when the sediment discharge process is carried out for the first time in the power generation system 20 of the present embodiment, the figures are shown assuming such cases. However, sediment S may remain in the sediment discharge path 21 on the downstream side of the sediment discharge gate 26 before the start of the sediment discharge process.

[0087] In the sediment discharge process in the present embodiment, when the sediment discharge gate 26 is opened from the state shown in FIG. 10A, due to the water pressure of the water W stored in the storage pond 5 and the scouring force by which the flow of the water W transports sediment and the like, the sediment S loosened in the sediment stirring process starts to flow through the sediment discharge path 21 (sediment discharge pipe 21a) as the sediment discharge flow S1 together with the stored water W, reaches the impeller device 30 or the crusher 40 as shown in FIG. 10B, and further flows through the sediment discharge path 21 (sand discharge path 21c) toward the downstream side. Also, in the sediment discharge process in the present embodiment, at approximately the same time as the timing of opening the sediment discharge gate 26, the supply of external power to the power generation device main body 31 or the power generation device 41 (not shown) of the power generation device is started. Thereby, the power generation device main body is driven by external power to rotate the impeller device 30 or the crusher 40. Therefore, even in the initial stage of the start of the sediment discharge process when the flow velocity of the sediment discharge flow S1 is relatively low, kinetic energy is imparted to the sediment discharge flow S1 by the rotation of the impellers 30a and 46, so that the sediment discharge flow S1 easily circulates in the sediment discharge path 21. In addition, in order to prevent the impellers 30a and 46 from obstructing the flow of the sand discharge flow S1, the timing to start driving the power generation device main body by external power may be before the sand discharge flow S1 reaches the impeller device 30 or the crusher 40, that is, before the state shown in FIG. 10B is reached.

[0088] Thus, in the power generation system using dam sediment according to the second embodiment, the power generation device main body 31 or the power generation device main body (not shown) of the power generation device 41 may be configured to rotationally drive the impeller devices 30 and 45 when receiving power supply. Also, in the power generation method using dam sediment in the present embodiment, in the sand discharge process, power may be supplied to the power generation device 22 during a specified period after the start of sand discharge (after the sand discharge gate 26 is opened) to convert electrical energy into the kinetic energy of the sand discharge flow S1. That is, in the power generation method using dam sediment in the present embodiment, in the sand discharge process, during a specified period after the start of sand discharge, power may be supplied to the power generation device main body 31 or the power generation device main body (not shown) of the power generation device 41 to drive the generator main body and rotate the impeller devices 30 and 45. Here, the above-mentioned specified period may be, for example, as described later, the period until the flow velocity of the sand discharge flow S1 in the sand discharge path 21 exceeds a specified value.

[0089] As the sand discharge flow S1 flows through the sand discharge path 21, as shown in FIG. 10C, the sand discharge flow S1 starts to be discharged into the downstream area R2 of the dam. When the sand discharge flow S1 starts to be discharged into the downstream area R2 of the dam, due to the head difference between the height of the upstream end of the sand discharge pipe 21a and the height of the downstream end of the sand discharge path 21c, the principle of the siphon works, and even if there is a location in the path of the sand discharge path 21 that is higher than the height of the upstream end of the sand discharge pipe 21a, the sand discharge flow S1 continues to flow through the sand discharge path 21.

[0090] In the sand discharge process in the present embodiment, if the flow velocity of the sand discharge flow S1 in the sand discharge path 21 exceeds a specified value, the supply of external power to the power generation device main body is stopped, and power generation is started by the rotation of the impeller devices 30 and 45. For this purpose, the flow velocity of the sand discharge flow S1 in the sand discharge path 21 may be measured by a flow meter or the like. That is, in the sand discharge process of the present embodiment, after the start of sand discharge, if the flow velocity of the sand discharge flow S1 in the sand discharge path 21 is equal to or lower than a specified value, power is supplied to the power generation device 22 to convert electrical energy into the kinetic energy of the sand discharge flow S1. If the flow velocity of the sand discharge flow S1 in the sand discharge path 21 exceeds the specified value, the supply of power to the power generation device 22 is stopped, and the kinetic energy of the sand discharge flow is converted into electrical energy in the power generation device 22 (the power generation process is started). Specifically, in the sand discharge process of the present embodiment, after the start of sand discharge, if the flow velocity of the sand discharge flow S1 in the sand discharge path 21 is equal to or lower than a specified value, power is supplied to the power generation device main body to drive the generator main body to rotate the impeller devices 30 and 45. If the flow velocity of the sand discharge flow S1 in the sand discharge path 21 exceeds the specified value, the supply of power to the power generation device main body is stopped, and the power generation process of converting the kinetic energy of the sand discharge flow S1 into electrical energy by the power generation device 22 is carried out.

[0091] In the power generation method using the dam sediment of the present embodiment, the switching operation for stopping the supply of external power to the power generation device main body and starting power generation by the power generation device main body may be manually switched by an operator, or may be automatically switched based on the measurement results of the flow velocity meter as described above.

[0092] In addition, a motor may be provided separately from the power generation device main body so that the impeller devices 30 and 45 can be rotated by the motor.

[0093] In addition, the power generated by the power generation system 20 and the power generation method using the dam sediment of the present embodiment may be transmitted in the same manner as the hydroelectric power generation facility 2, or may be appropriately used within the dam facility, for example, when a sand discharge pipe is laid across the top of the dam 7c and electric motor equipment such as a pump (such as a vacuum pump) for transporting the sediment S by the sand discharge pipe is provided, it may be used as the driving power of the electric motor equipment.

[0094] Therefore, according to the power generation system 20 using dam sediment and the power generation method using dam sediment of the present embodiment, similar to the first embodiment, it is possible to effectively utilize the kinetic energy (potential energy of the sediment S) during the sediment discharge of the sediment S that was simply discharged into the downstream area R2 of the dam and wasted, and perform power generation.

[0095] Also, in the power generation system 20 using dam sediment and the power generation using dam sediment of the present embodiment, even when using sediment S with low potential energy, it is possible to ensure kinetic energy equivalent to that of hydroelectric power generation and ensure power generation efficiency equivalent to that of hydroelectric power generation.

[0096] Furthermore, it is possible to use hydroelectric power generation and power generation using dam sediment in combination, and enhance the value of the dam 1 for hydroelectric power generation.

[0097] Also, in the power generation system 20 using dam sediment and the power generation using dam sediment of the present embodiment, the power generation devices 22 and 41 include a turbine device 30 and 45 that receive the sediment discharge flow S1 and rotate around the axis O1, and a power generation device main body (31) that generates power by the rotation of the turbine devices 30 and 45. By using power generation devices 22 and 41 similar to such hydroelectric power generation facilities 2, it becomes possible to perform sediment power generation.

[0098] Furthermore, a crusher 40 is used as the power generation device 22, or a configuration similar to the crusher 40 is adopted. This eliminates the need to newly research and develop a power generation device 22 that has sufficient durability against the sediment discharge flow S1 from scratch. Also, during the sediment discharge of the sediment S, the crusher 40 of the pre-existing crushing equipment can be diverted, or a power generation device with specifications substantially equivalent to the crusher 40 can be newly prepared, and it becomes possible to convert the kinetic energy of the sediment discharge flow S1 into electrical energy and generate power.

[0099] Note that in the power generation system 20 using dam sediment of this embodiment, since the power generation device 22 is arranged on the downstream side of the dam body 7, compared with the power generation systems 20 according to the fourth and fifth embodiments described later, when adding a power generation system 20 using dam sediment to the existing dam 1, it can be added relatively easily. That is, for example, when providing the power generation system 20 using dam sediment of this embodiment to the existing dam 1, the modification content for the existing dam 1, such as providing a sand discharge channel 21 in the existing dam body 7, is relatively small. Therefore, for example, it is relatively easy to provide the power generation system using dam sediment of this embodiment to the existing dam 1.

[0100] Also, it is possible to achieve the same operational effects as in the first embodiment. For example, in the power generation method using dam sediment of this embodiment, the sediment S is loosened in advance, and the sediment is discharged by utilizing the water pressure of the water W stored in the storage pond 5 and the scouring force of the flow of the water W. Therefore, it is also possible to eliminate the two dam operation steps of the conventional (b) lowering of the water level in the storage pond 5 and (d) recovery of the water level in the storage pond 5, which require a great deal of time and a great deal of labor for observation and management over time. Thus, it becomes possible to efficiently and effectively discharge the sediment, and power generation can be performed with the sediment flow S1. That is, it becomes possible to achieve even more remarkable operational effects.

[0101] Also, by loosening the sediment S in advance, the influence range of the scouring force on the sediment S, and thus the sediment dischargeable range, can be significantly expanded. Therefore, it becomes possible to significantly increase the sediment discharge efficiency and thus the power generation efficiency by simply taking one step (one effort) of loosening the sediment S in advance.

[0102] (Third Embodiment) Hereinafter, with reference to FIGS. 11 and 12, a power generation system using dam sediment and a power generation method using dam sediment according to the third embodiment will be described. Here, in this embodiment, a part of the configuration of the sediment discharge facility 4 is different from that of the second embodiment. Therefore, for the same configuration as in the second embodiment, the detailed description thereof will be omitted by attaching the same reference numerals. FIG. 11 is a diagram schematically showing an example of a power generation system using dam sediment. FIG. 12 is a diagram schematically showing a cross-sectional view taken along the line A-A in FIG. 11.

[0103] (Power Generation System Using Dam Sediment) Similar to the first and second embodiments, the sediment discharge facility 4 of this embodiment includes a power generation system 20 using dam sediment for generating power using the sediment S deposited on the bottom 6 of the dam reservoir 5.

[0104] Also, similar to the second embodiment, the power generation system 20 using dam sediment of this embodiment includes, as shown in FIG. 11, a sediment discharge channel 21 for discharging the sediment S deposited on the bottom 6 of the dam reservoir 5 as a sediment discharge flow S1 to the downstream side R2 of the dam body 7, and a power generation device 22 provided in the sediment discharge channel 21 for converting the kinetic energy of the sediment discharge flow S1 into electrical energy.

[0105] Similar to the second embodiment, the sediment discharge channel 21 of this embodiment is provided, for example, penetrating from the back surface 7b to the front surface 7a of the dam body 7 on the lower side of the dam body 7, and includes a sediment discharge pipe (sediment discharge outlet) 21a for sending the sediment S in the upper dam area R1 to the lower dam area R2, and the discharge port 21b of this sediment discharge pipe 21a is connected to a flow path 61 (to be described later) of the power generation device 22.

[0106] Note that the sediment discharge pipe 21a for sending the sediment S in the upper dam area R1 to the lower dam area R2 does not necessarily have to be limited to a sediment discharge pipe penetrating the dam body 7, similar to the second embodiment, as long as it can send the sediment S in the upper dam area R1 to the lower dam area R2 and further to the power generation device 22 of this embodiment. For example, it may be a sediment discharge pipe straddling the top 7c of the dam body 7 and extending to the lower dam area R2, a sediment discharge pipe extending around the dam body 7 to the lower dam area R2, a sediment discharge pipe extending through the ground G below the dam body 7 to the lower dam area R2, etc. Also, the sediment discharge pipe may be laid so as to send the dredged sediment S to the power generation device 22 of this embodiment. Furthermore, these sediment discharge pipes may be selectively provided as appropriate.

[0107] The power generation device 22 of the present embodiment includes a conversion device 50 including an endless belt body 52 that travels receiving the sand discharge flow S1 and a rotating body 53 that rotates by the travel of the endless belt body 52, and a power generation device main body 51 that generates power by the rotation of the rotating body 53 in the conversion device 50. As with the generator 12 of the hydroelectric power facility 2, the power generation device main body 51 can apply a generator that generates power by the rotation of the rotating body 53. In the power generation device 22 of the present embodiment, a speed increasing device (not shown) may be used to rotationally drive the power generation device main body 51 at a rotational speed higher than the rotational speed of the rotating body 53.

[0108] Hereinafter, the structure of the power generation device 22 of the present embodiment will be further described. As shown in FIGS. 12 and 13, in the power generation device 22 of the present embodiment, for example, the conversion device 50 and the power generation device main body 51 are arranged inside a structure 60 made of concrete. Inside the structure 60, a flow path 61 for allowing the sand discharge flow S1 to flow is formed. That is, the sand discharge path 21 of the present embodiment includes the flow path 61 in the structure 60.

[0109] The flow path 61 of the present embodiment may be provided to be horizontal from the upstream side to the downstream side (from the left side to the right side in FIG. 11), or may be provided to be inclined so that the height decreases from the upstream side to the downstream side. In this regard, the same applies to the power generation device 22 in the second embodiment described above. In the structure in which the impeller device 30 and the power generation device 41 in the second embodiment are arranged, the flow path for allowing the sand discharge flow S1 to flow may be provided to be inclined.

[0110] The conversion device 50 of the present embodiment is a device provided in the flow path 61 for converting the kinetic energy of the sand discharge flow S1 into the kinetic energy of the rotating body 53, and has a structure imitating, for example, a belt conveyor. That is, in the power generation device 22 of the present embodiment, the conversion device 50 includes, as the rotating body 53, two pulleys 53A spaced apart along the flow direction of the sand discharge flow S1, and as the endless belt body 52, a belt 52A wound around the two pulleys 53A.

[0111] In the conversion device 50 of the present embodiment, a plurality of horizontal bars 54 are provided upright on the surface of the belt 52A at intervals in the longitudinal direction of the belt 52A and extending in the width direction of the belt 52A.

[0112] The conversion device 50 of the present embodiment is disposed above the flow path 61, but it may be disposed below or on the side of the flow path 61. If the conversion device 50 is disposed above the flow path 61, it becomes easy to prevent leakage of the sand discharge flow S1 to the conversion device 50 side.

[0113] In the conversion device 50 of the present embodiment, among the plurality of horizontal bars 54, the horizontal bars 54 on the belt 52A located below the two pulleys 53A are immersed in the sand discharge flow S1 in the flow path 61. Therefore, when the sand discharge flow S1 flows downstream in the flow path 61, the horizontal bars 54 immersed in the sand discharge flow S1 are pressed downstream. As a result, the belt 52A located below the two pulleys 53A travels downstream, and the two pulleys 53A, and thus the power generation device main body 51, are rotationally driven.

[0114] In the conversion device 50 of the present embodiment, it is configured to receive force from the sand discharge flow S1 in the flow path 61 by a plurality of horizontal bars 54 extending in the width direction and the thickness direction of the belt 52A. Therefore, compared with the impeller device 30 and the power generation device 41 in the second embodiment described above, the area of the surface receiving force from the sand discharge flow S1 can be increased, and the burden on the conversion device 50 can be reduced. In the conversion device 50 of the present embodiment, each of the plurality of horizontal bars 54 may be a plate-like member, or may have a shape capable of holding the accumulated sand S and water W in the sand discharge flow S1, such as a bucket in a bucket elevator. Further, in the conversion device 50 of the present embodiment, the endless belt 52 is not limited to the belt 52A, and may be a chain or the like. When the endless belt 52 is a chain, the rotating body 53 is preferably a sprocket that can engage with the chain.

[0115] (Power generation method using dam sediment) Also, when generating electricity using the kinetic energy of the sediment flow S1 by using the power generation system 20 using dam sediment of this embodiment (in the power generation method using dam sediment of this embodiment), similar to the first and second embodiments, first, the sediment S deposited on the bottom 6 of the dam reservoir 5 is loosened at the bottom 6 (sediment stirring step: see FIG. 5).

[0116] Then, the sediment discharge gate 26 is opened, and using the water pressure of the water W stored in the reservoir 5 and the scouring force of the flow of the water W to carry sediment and the like, the sediment S loosened in the sediment stirring step is discharged as the sediment flow S1 through the sediment discharge pipe 21a together with the stored water W (sediment discharge step). Further, the sediment flow S1 sent from the sediment discharge pipe 21a is received by the power generation device main body (generator) of the power generation device 22, and the conversion device 50 is rotated by the kinetic energy of this sediment flow S1 to generate electricity, and the sediment flow S1 is discharged to the downstream area R2 of the dam (power generation step: see FIG. 6).

[0117] Here, for example, it is preferable that the power generation device main body 51 is configured so that the power generation device main body 51 can function as an electric motor by supplying power from the outside. Then, in the sediment discharge step, it is preferable to drive the power generation device main body 51 by supplying power from the outside to the power generation device main body 51 so as to run the belt 52A. Note that an electric motor may be provided separately from the power generation device main body 51, and the belt 52A may be run by the electric motor. Thereby, the sediment flow S1 becomes easier to flow in the flow path 61. That is, in the power generation system using dam sediment according to the third embodiment, similar to the power generation system using dam sediment according to the second embodiment, the power generation device 22 is preferably configured to be able to convert electrical energy into the kinetic energy of the sediment flow S1 by receiving power supply. Hereinafter, in the sediment discharge step, driving the power generation device main body 51 by supplying power from the outside to the power generation device main body 51 will be described.

[0118] In the sand discharge process of this embodiment, when the sand discharge gate 26 is opened, due to the water pressure of the water W stored in the water storage tank 5 and the scouring force carried by the flow of the water W to transport sediment and the like, the sand deposit S loosened in the sand deposit agitation process starts to flow through the sand discharge path 21 (sand discharge pipe 21a) as the sand discharge flow S1 together with the stored water W, reaches the conversion device 50, and further flows through the sand discharge path 21 (flow path 61) toward the downstream side. Also, in the sand discharge process of this embodiment, at approximately the same time as the sand discharge gate 26 is opened, the supply of external power to the main body 51 of the power generation device is started. As a result, the main body 51 of the power generation device is driven by external power to rotate the pulley 53A and run the belt 52A. Therefore, even in the initial stage of the start of the sand discharge process when the flow velocity of the sand discharge flow S1 is relatively low, kinetic energy is imparted to the sand discharge flow S1 by the running of the belt 52A, making it easier for the sand discharge flow S1 to flow through the sand discharge path 21. In order to prevent the cross bar 54 from obstructing the flow of the sand discharge flow S1, the timing of starting the drive of the main body 51 of the power generation device by external power is preferably before the sand discharge flow S1 reaches the conversion device 50.

[0119] Thus, in the power generation system using dam sand deposits according to the third embodiment, the main body 51 of the power generation device is preferably configured to run the belt 52A when receiving power supply. Also, in the power generation method using dam sand deposits in this embodiment, in the sand discharge process, during a specified period after the start of sand discharge (after the sand discharge gate 26 is opened), power may be supplied to the power generation device 22 to convert electrical energy into the kinetic energy of the sand discharge flow S1. That is, in the power generation method using dam sand deposits in this embodiment, in the sand discharge process, during a specified period after the start of sand discharge, power may be supplied to the main body 51 of the power generation device to drive the main body 51 of the power generation device, rotate the pulley 53A, and run the belt 52A. Here, the above-mentioned specified period may be, for example, as described later, the period until the flow velocity of the sand discharge flow S1 in the sand discharge path 21 exceeds a specified value.

[0120] As the sand discharge flow S1 flows through the sand discharge path 21, the sand discharge flow S1 starts to be discharged into the downstream area R2 of the dam.

[0121] In the sand discharge process of this embodiment, if the flow velocity of the sand discharge flow S1 in the sand discharge path 21 exceeds the specified value, the supply of external power to the power generation device main body 51 is stopped, and power generation is started by the running of the belt 52A, that is, the rotation of the pulley 53A. Therefore, it is advisable to measure the flow velocity of the sand discharge flow S1 in the sand discharge path 21 with a flow velocity meter or the like. That is, in the sand discharge process of this embodiment, after the start of sand discharge, if the flow velocity of the sand discharge flow S1 in the sand discharge path 21 is below the specified value, power is supplied to the power generation device 22 to convert electrical energy into the kinetic energy of the sand discharge flow S1. If the flow velocity of the sand discharge flow S1 in the sand discharge path 21 exceeds the specified value, the supply of power to the power generation device 22 is stopped, and the kinetic energy of the sand discharge flow is converted into electrical energy in the power generation device 22 (the power generation process is started). Specifically, in the sand discharge process of this embodiment, after the start of sand discharge, if the flow velocity of the sand discharge flow S1 in the sand discharge path 21 is below the specified value, power is supplied to the power generation device main body 51 to drive the power generation device main body 51 to rotate the pulley 53A. If the flow velocity of the sand discharge flow S1 in the sand discharge path 21 exceeds the specified value, the supply of power to the power generation device main body 51 is stopped, and the power generation process of converting the kinetic energy of the sand discharge flow S1 into electrical energy by the power generation device 22 is carried out.

[0122] In the power generation method using dam sediment in this embodiment, the switching operation for stopping the supply of external power to the power generation device main body 51 and starting power generation by the power generation device main body 51 may be manually switched by an operator, or may be automatically switched based on the measurement results of the flow velocity meter as described above.

[0123] In addition, a motor may be provided separately from the power generation device main body 51 so that at least one of the two pulleys 53A on the upstream side and the downstream side can be rotated by the motor.

[0124] Note that the electric power generated by the power generation system 20 using dam sediment and the power generation method of this embodiment can be transmitted in the same manner as the hydroelectric power facility 2, or, for example, when a sand discharge pipe is laid across the top of the dam 7c, electric equipment such as a pump (such as a vacuum pump) for transporting the sediment S through the sand discharge pipe is provided, it may be appropriately used within the dam facility, such as being used as the driving power for the electric equipment.

[0125] Therefore, according to the power generation system 20 using dam sediment and the power generation method using dam sediment of this embodiment, similar to the first and second embodiments, it is possible to effectively utilize the kinetic energy (the potential energy of the sediment S) during the sand discharge of the sediment S that was simply discharged into the downstream area R2 of the dam and wasted, and generate electricity.

[0126] Also, in the power generation system 20 using dam sediment and the power generation using dam sediment of this embodiment, even when using sediment S with low potential energy, it is possible to ensure kinetic energy equivalent to that of hydroelectric power and ensure power generation efficiency equivalent to that of hydroelectric power.

[0127] Furthermore, hydroelectric power and power generation using dam sediment can be used in combination, which can enhance the value of the dam 1 for hydroelectric power.

[0128] Also, in the power generation system 20 using dam sediment and the power generation using dam sediment of this embodiment, the power generation device 22 includes an endless belt 52 that travels receiving the sand discharge flow S1, a rotating body 53 that rotates due to the travel of the endless belt 52, and a power generation device main body 51 that generates electricity due to the rotation of the rotating body 53. Thereby, the kinetic energy of the sand discharge flow S1 is used to run the endless belt 52 and rotate the rotating body 53, and the rotational energy of the rotating body 53 can be converted into electrical energy by the power generation device main body 51 to generate electricity.

[0129] In the power generation system 20 using dam sediment of the present embodiment, since the power generation device 22 is arranged on the downstream side of the dam body 7, compared with the power generation systems 20 according to the fourth and fifth embodiments described later, when adding a power generation system 20 using dam sediment to the existing dam 1, it can be added relatively easily. That is, for example, when providing the power generation system 20 using dam sediment of the present embodiment to the existing dam 1, the modification content for the existing dam 1, such as providing a sediment discharge channel 21 in the existing dam body 7, is relatively small. Therefore, for example, it is relatively easy to provide the power generation system using dam sediment of the present embodiment to the existing dam 1.

[0130] Also, it is possible to achieve the same operational effects as in the first and second embodiments. For example, in the power generation method using dam sediment of the present embodiment, the sediment S is loosened in advance, and the sediment is discharged by utilizing the water pressure of the water W stored in the storage pond 5 and the scouring force of the flow of the water W. Therefore, it is also possible to eliminate the two dam operation steps of (b) the water level drop of the storage pond 5 and (d) the water level recovery of the storage pond 5 in the conventional method, which require a large amount of time and a great deal of labor for observation and management. Thus, it becomes possible to efficiently and effectively discharge the sediment, and power generation can be performed with the sediment discharge flow S1. That is, it becomes possible to achieve even more remarkable operational effects.

[0131] Also, by loosening the sediment S in advance, the influence range of the scouring force on the sediment S, and thus the sediment dischargeable range, can be significantly expanded. Therefore, by simply taking one step (one effort) of loosening the sediment S in advance, it becomes possible to significantly improve the sediment discharge efficiency and thus the power generation efficiency.

[0132] (Fourth Embodiment) Hereinafter, with reference to FIG. 13, a power generation system using dam sediment and a power generation method using dam sediment according to the fourth embodiment will be described. Here, in this embodiment, a part of the configuration of the sediment discharging facility 4 is different from that of the second embodiment. Specifically, in this embodiment, the power generation system 20 of the second embodiment is different in that the power generation device 22 according to the second embodiment is arranged inside the dam body 7. Therefore, for the same configurations as those in the second embodiment, the same reference numerals are used and detailed descriptions thereof are omitted. FIG. 13 is a diagram schematically showing an example of a power generation system using dam sediment according to the fourth embodiment.

[0133] (Power generation system using dam sediment) Similar to the first to third embodiments, the sediment discharging facility 4 of this embodiment includes a power generation system 20 using dam sediment for generating power by using the sediment S deposited on the bottom 6 of the dam reservoir 5.

[0134] Also, similar to the second embodiment, as shown in FIG. 13, the power generation system 20 using dam sediment of this embodiment includes a sediment discharging channel 21 for discharging the sediment S deposited on the bottom 6 of the dam reservoir 5 as a sediment flow S1 to the downstream side R2 of the dam body 7, and a power generation device 22 provided in the sediment discharging channel 21 for converting the kinetic energy of the sediment flow S1 into electrical energy.

[0135] The power generation device 22 of this embodiment is arranged inside the dam body 7. That is, in the power generation device 22 of this embodiment, a turbine device 30 having a runner 30a that rotates around an axis receiving the sediment flow S1, and a power generation device main body 31 that generates power by the rotation of the turbine device 30 are arranged inside the dam body 7. In this embodiment, a power generation device 41 that uses the crusher 40 of the same crushing facility as that in the second embodiment, or a power generation device 41 having specifications substantially equivalent to those of the crusher 40 may be arranged inside the dam body 7.

[0136] (Power generation method using dam sediment) In the power generation method using the power generation system 20 with dam sediment according to this embodiment, similar to the first to third embodiments, power generation can be achieved by performing a sediment stirring process (see FIG. 5) and a power generation process (see FIG. 6).

[0137] In the power generation system 20 with dam sediment according to this embodiment, since the power generation device 22 is arranged inside the dam body 7, it is relatively easy to secure an installation space for the power generation device 22. Further, in the power generation system 20 with dam sediment according to this embodiment, if it is at the time of constructing a new dam 1, the power generation device 22 can be relatively easily arranged inside the dam body 7.

[0138] (Fifth Embodiment) Hereinafter, with reference to FIG. 14, a power generation system with dam sediment and a power generation method with dam sediment according to the fifth embodiment will be described. Here, in this embodiment, a part of the configuration of the sediment discharging facility 4 is different from that of the third embodiment. Specifically, in this embodiment, it is different from the power generation system 20 of the third embodiment in that the power generation device 22 according to the third embodiment is arranged inside the dam body 7. Therefore, for the same configuration as that of the third embodiment, the same reference numerals are used and the detailed description thereof is omitted. FIG. 14 is a diagram schematically showing an example of a power generation system with dam sediment according to the fifth embodiment.

[0139] (Power Generation System with Dam Sediment) The sediment discharging facility 4 of this embodiment, similar to the first to fourth embodiments, includes a power generation system 20 with dam sediment for performing power generation using the sediment S deposited on the bottom 6 of the dam reservoir 5.

[0140] Further, the power generation system 20 with dam sediment of this embodiment, similar to the third embodiment, as shown in FIG. 13, includes a sediment discharging channel 21 for discharging the sediment S deposited on the bottom 6 of the dam reservoir 5 as a sediment discharge flow S1 to the downstream side R2 of the dam body 7, and a power generation device 22 provided in the sediment discharging channel 21 for converting the kinetic energy of the sediment discharge flow S1 into electric energy.

[0141] The power generation device 22 of this embodiment is disposed within the embankment 7. That is, in the power generation device 22 of this embodiment, a conversion device 50 including an endless belt 52 that travels receiving the sand discharge flow S1 and a rotating body 53 that rotates due to the travel of the endless belt 52, and a power generation device main body 51 that generates power by the rotation of the rotating body 53 in the conversion device 50 are disposed within the embankment 7. In the power generation device 22 of this embodiment, as shown in FIG. 14, the conversion device 50 is disposed such that the belt 52A travels along the sand discharge path 21 that penetrates from the back surface 7b to the front surface 7a of the embankment 7. Although not shown, when a part of the sand discharge path 21 extends within the embankment 7, for example, in the depth direction of the paper in FIG. 14, the conversion device 50 may be disposed such that the belt 52A travels along the depth direction of the paper in FIG. 14.

[0142] (Power generation method using dam sediment) In the power generation method using the power generation system 20 with dam sediment of this embodiment, similar to the first to fourth embodiments, power generation can be achieved by performing a sediment stirring step (see FIG. 5) and a power generation step (see FIG. 6).

[0143] In the power generation system 20 with dam sediment of this embodiment, since the power generation device 22 is disposed inside the embankment 7, it is relatively easy to secure an installation space for the power generation device 22. That is, the power generation device 22 can be installed without securing an installation space for the power generation device 22 in the downstream area R2 of the dam. Also, in the power generation system 20 with dam sediment of this embodiment, if it is at the time of newly constructing the dam 1, it is relatively easy to dispose the power generation device 22 inside the embankment 7.

[0144] FIG. 15 is a diagram schematically showing a modified example of the power generation system using dam sediment of the fifth embodiment. As shown in FIG. 15, a part of the power generation device 22 of this embodiment may protrude downstream from the front surface 7a of the embankment 7. That is, at least a part of the power generation device 22 of this embodiment may be disposed inside the embankment 7. Note that, although not shown in the drawings, a part of the power generation device 22 according to the fourth embodiment may protrude downstream from the front surface 7a of the embankment 7. Since at least a part of the power generation device 22 is arranged inside the embankment 7, it is relatively easy to secure an installation space for the power generation device 22.

[0145] As described above, several embodiments of the power generation system using dam sediment and the power generation method using dam sediment of the present disclosure have been described. However, the present disclosure is not limited to the above several embodiments, and can be appropriately changed without departing from the gist thereof.

[0146] For example, in each embodiment, the dam according to the present disclosure has been described as a multipurpose dam. However, it does not necessarily have to be a multipurpose dam. That is, the dam according to the present disclosure includes an embankment 7, can store water W in the upstream area R1 of the dam by the embankment 7, and sediment S is generated on the bottom 6 with the water storage. The dam 1 requires the discharge of this sediment S. As long as it is provided with the power generation system 20 (sediment discharge facility 4) using dam sediment of the above several embodiments, there is no particular need to limit other configurations as in the above several embodiments.

[0147] Of course, the configurations and modification examples of each embodiment may be combined.

[0148] Furthermore, in each embodiment, after loosening the sediment S deposited on the bottom 6 of the water storage tank 5 in the sediment stirring step, it is discharged as a sediment flow S1 through a sediment discharge channel and a sediment discharge pipe. However, if the sediment S can be discharged without using the sediment stirring step, the sediment stirring step does not necessarily have to be performed. For example, if facilities for controlling the generation area of the sediment S are provided, the position of the suction port of the sediment discharge pipe for sucking the sediment S can be changed, or a plurality of suction ports are provided, etc., and the sediment discharge efficiency and thus the power generation efficiency can be suitably ensured, the sediment stirring step does not have to be performed.

[0149] In addition, the sand discharge channel, sand release channel, sand discharge pipe, and ultimately the power generation device may be installed at a location where a large head of the sand discharge flow S1 can be obtained, or extended to a location where a large head of the sand discharge flow S1 can be obtained, which is of course acceptable.

Explanation of Reference Numerals

[0150] 1 Dam 2 Hydroelectric power generation facility 3 Water release facility 4 Sand discharge facility 5 Dam reservoir 6 Seabed 7 Dam body 7a Front face 7b Rear face 7c Dam top 13 Transformer 14 Power transmission facility 15 Water release channel 20 Power generation system using dam sediment 21 Sand discharge channel 21a Sand discharge pipe (sand discharge outlet) 21b Discharge port 21c Sand release channel 21d Flow guiding wall 22 Power generation device 23 Vibration power generation device 24 Impact power generation plate 30 Turbine device 30a Turbine 31 Power generation device body 40 Crusher 41 Power generation device 42 Discharge port 43 Inlet 44 Housing 45 Turbine device 46 Turbine 47 Rotating shaft 50 Conversion device 51 Power generation device body 52 Endless belt 52A Belt 53 Rotating body 53A Pulley 54 Cross bar 61 Flow path G Ground R1 Upstream side of the dam Downstream side of R2 Dam S Sand deposit S1 Sand discharge flow W Water (stored water)

Claims

1. A power generation system for generating power using sediment deposited on the bottom of a body of water, comprising: a sand flushing channel for discharging the sediment deposited on the bottom of the water as a sand flushing flow to the opposite side of the bottom of the water across the bank; a power generation device provided in the sand discharge channel and converting the kinetic energy of the sand discharge flow into electrical energy; The sand flushing channel includes at least one of a first sand flushing pipe penetrating the embankment, a second sand flushing pipe extending to the opposite side by bypassing the embankment and not straddling the embankment top, and a third sand flushing pipe extending to the opposite side through the ground below the embankment. Power generation system.

2. The power generation device includes: An impact power generation plate for colliding the sand discharge flow and converting impact energy into power generation energy, The power generation system according to claim 1 .

3. A power generation system for generating power using sediment deposited on the bottom of a body of water, comprising: a sand flushing channel for discharging the sediment deposited on the bottom of the water as a sand flushing flow to the opposite side of the bottom of the water across the bank; a power generation device provided in the sand discharge channel and converting the kinetic energy of the sand discharge flow into electrical energy; The power generation device includes an impact power generation plate for colliding the sand discharge flow and converting impact energy into power generation energy, The sand discharge path is A sand flushing pipe penetrating the bank body; a guide wall provided on the front surface of the embankment and forming a sand discharge path for guiding the sand discharge flow discharged from the discharge port of the sand discharge pipe to the opposite side, The impulse power generating plate is attached to at least a part of the wall surface of the flow guide wall. Power generation system.

4. A power generation system for generating power using sediment deposited on the bottom of a body of water, comprising: a sand flushing channel for discharging the sediment deposited on the bottom of the water as a sand flushing flow to the opposite side of the bottom of the water across the bank; A power generation device is provided in the sand discharge channel and converts the kinetic energy of the sand discharge flow into electrical energy. The power generation device includes: An impeller device that receives the sand flushing flow and rotates around an axis; a power generation device body that generates power by rotation of the impeller device, The power generating device can be used as a crusher, The crusher is configured so that the direction of rotation of the rotating shaft during power generation is different from that during crushing. Power generation system.

5. A power generation system for generating power using sediment deposited on the bottom of a body of water, comprising: a sand flushing channel for discharging the sediment deposited on the bottom of the water as a sand flushing flow to the opposite side of the bottom of the water across the bank; a power generation device provided in the sand discharge channel and converting the kinetic energy of the sand discharge flow into electrical energy; The power generation device includes: an endless belt that travels while receiving the sand discharge flow; a rotor that rotates as the endless belt travels; a power generation device main body that generates power by rotation of the rotor, The lowest position of the travel path of the endless belt is above the water surface of the sand flushing flow flowing through a flow path included in the sand flushing channel. Power generation system.

6. The power generating device is disposed on the opposite side. The power generation system according to claim 4 or 5.

7. At least a part of the power generating device is disposed inside the bank. The power generation system according to claim 4 or 5.

8. A power generation method for generating power using the power generation system according to any one of claims 1 to 7, comprising: a sediment stirring step of loosening the sediment deposited on the bottom of the water at the bottom of the water; a sand discharge process in which the sediment loosened in the sediment stirring process is discharged together with the stored water as the sand discharge flow through the sand discharge channel; A power generation process in which the kinetic energy of the sand discharge flow is converted into electrical energy by the power generation device. Power generation method.

9. In the sand flushing process, during a first period, electrical energy of electric power supplied from an external source to the power generating device is converted into kinetic energy of a sand flushing flow, and after the first period has elapsed, the supply of electric power from the external source to the power generating device body is stopped; The power generation step is carried out after the first period has elapsed in the sand removal step. The power generation method according to claim 8.

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