JP7537945B2 - Rainwater Power Generation System - Google Patents

Description

The present invention relates to a rainwater utilization power generation system.

Traditionally, electricity has been generated using natural forces such as wind and solar power, even if the scale of use is small. In recent years, one method of generating electricity using natural forces is to use rainwater that falls on a building, drop it from the top of the building, and generate electricity using a generator installed at the bottom of the building (small hydroelectric power generation).
Various proposals have been made regarding power sources, i.e. water wheels, used in generating electricity using rainwater that falls on such buildings (see, for example, Patent Documents 1 and 2).

Japanese Patent Application Publication No. 8-237997 Registered Utility Model No. 3171044

However, conventional methods for generating electricity using rainwater have the following problems.
In general, hydroelectric power generation is achieved by converting the potential energy of water into kinetic energy. However, there are few buildings that are tall enough (head) and have a large land area (area where rain falls) to increase the flow rate. In other words, there are many buildings that cannot be fitted with small hydroelectric power generation equipment because either the building height (head) or the land area (flow rate) is insufficient, resulting in a small power output, making it difficult to realize.

On the other hand, the advantage of small-scale hydroelectric power generation is that the equipment required for generating electricity only requires a small installation area. However, when installing it on the outside of a building, it is necessary to consider how it will blend in with the building and not spoil the scenery, and there is room for improvement in this regard.

The present invention was made in consideration of the above-mentioned problems, and aims to provide a rainwater power generation system that can generate electricity by effectively utilizing the energy contained in rainwater, while improving the appearance of the building.

To achieve the above object, the rainwater utilization power generation system of the present invention is a rainwater utilization power generation system that generates power by using rainwater that falls on the top of a building, and is characterized in that it includes a rainwater collection facility that collects the rainwater that falls on the top of a plurality of buildings via a collection pipe to a rainwater storage unit provided on the top of a first building of any one of the plurality of buildings, and a hydroelectric generator that is provided below the rainwater storage unit and generates power by using the hydroelectric power of the rainwater that is allowed to flow down naturally from the rainwater storage unit, and that the rainwater storage unit is located at a lower position than the top of at least a second building other than the first building of the plurality of buildings.

In this invention, rainwater that falls on the tops of multiple buildings is collected through a collection pipe in a rainwater storage section installed in the top of the first building, and the rainwater stored in the rainwater storage section is allowed to flow down naturally to generate electricity using a hydroelectric generator. In this way, in this invention, by increasing the flow rate of rainwater used for small-scale hydroelectric power generation, the energy contained in the rainwater can be effectively utilized, and the power output of the small-scale hydroelectric power generation can be increased.
In addition, in the present invention, since the rainwater storage section provided at the top of the first building is at a lower height than the top of the second building, the rainwater that falls on the second building can be collected by using a collection pipe to flow into the rainwater storage section of the first building, making use of the head difference. In this way, in the present invention, even if the building is low in height, the rainwater that falls on multiple buildings can be collected to increase the power generation output, so a sufficient amount of power can be secured.

Furthermore, in the present invention, the collection pipeline that utilizes the head difference can be placed inside or along a building, and the pipeline between the first building and the second building can also be laid, for example, above or underground, thereby realizing a good appearance that harmonizes with the buildings.
Furthermore, since the power generation equipment can be placed only near one of the multiple buildings, there is no need to install power generation equipment in each building, and a beautiful landscape that harmonizes with the buildings can be achieved.

In addition, in the rainwater utilization power generation system according to the present invention, it is preferable that the first building is set to a lower height than the second building.

In this case, since the first building is lower in height than the other second building, a rainwater storage unit can be installed on top of the first building. Then, when using a collection pipe to make the rainwater from the second building flow into the rainwater storage unit, collection can be performed by utilizing the head difference. In other words, even if the first building and the second building are far apart, the rainwater can be efficiently collected in the rainwater storage unit of the first building without any power.

The rainwater utilization power generation system according to the present invention may also be characterized in that the collection pipeline connected to the upper part of the second building and the rainwater storage section of the first building includes a first vertical pipe that is piped from the upper part to the lower part of the second building, a horizontal pipe that passes through the ground surface or underground between the second building and the first building, and a second vertical pipe that is piped from the lower part of the first building to the rainwater storage section.

In this case, the collection pipes installed between the first and second buildings will pass above ground or underground, allowing for layout planning that takes into account harmony with the buildings and minimizing damage to the building's scenery.

The rainwater power generation system of the present invention can generate electricity by effectively utilizing the energy contained in rainwater, while improving the appearance of the building.

1 is a perspective view showing a schematic configuration of a rainwater utilization power generation system according to a first embodiment of the present invention; FIG. 2 is a perspective view showing a state when there is no rain in the rainwater utilization power generation system shown in FIG. 1 .

Below, a rainwater utilization power generation system according to an embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the rainwater utilization power generation system 1 according to this embodiment generates power by utilizing rainwater W that falls on the upper parts 2a, 3a of a pair of buildings 2, 3. The height of one low-rise building 2 (first building) is lower than the other high-rise building 3 (second building). In this embodiment, the upper parts 2a, 3a of the buildings 2, 3 are the rooftops of the top floors. Here, in the following explanation, the rainwater W that falls on the upper part 2a of the low-rise building 2 is designated W2, and the rainwater that falls on the upper part 3a of the high-rise building 3 is designated W3.

The rainwater utilization power generation system 1 includes a rainwater collection facility 4 that collects rainwater W2, W3 that falls on the upper part 2a of a low-rise building 2 and the upper part 3a of a high-rise building 3 via a collection pipe 7 to a rainwater storage section 6 provided on the upper part 2a of the low-rise building 2, and a hydroelectric generator 5 that is provided below the rainwater storage section 6 and generates power using the hydraulic power of the rainwater W that flows naturally down from the rainwater storage section 6. The rainwater W3 that falls on the high-rise building 3 is sent from the upper part 3a of the high-rise building 3 to the rainwater storage section 6 via the collection pipe 7.

The rainwater storage unit 6 is a steel or concrete storage tank installed or constructed on the upper part 2a of the low-rise building 2. In the rainwater storage unit 6, rainwater W2 collected on the upper part 2a of the low-rise building 2 and rainwater W3 collected on the upper part 3a of the high-rise building 3 are collected and stored, for example, by roof drains (not shown) installed on the roofs of the buildings 2 and 3. The rainwater storage unit 6 has an inlet through which the rainwater W2 and W3 are sent from the low-rise building 2 and the high-rise building 3, and a drain outlet through which the rainwater W is discharged toward the hydroelectric generator 5.

The collecting pipeline 7 is, for example, a steel pipe, and is connected from the upper part 3a of the high-rise building 3 to the rainwater storage section 6. The collecting pipeline 7 has a first vertical pipe 71 that extends vertically from the upper part 3a to the lower part 3b in the high-rise building 3, a horizontal pipe 72 that passes through the ground surface or underground between the high-rise building 3 and the low-rise building 2 and is piped in a substantially horizontal direction, and a second vertical pipe 73 that extends vertically from the lower part 2b to the rainwater storage section 6 of the upper part 2a in the low-rise building 2. The upstream end 72a of the horizontal pipe 72 is connected to the lower end of the first vertical pipe 71, and the downstream end 72b is connected to the lower end of the second vertical pipe 73. Because the first vertical pipe 71 is installed in the high-rise building 3, which is higher than the low-rise building 2, the rainwater inlet 71a at the upper end of the first vertical pipe 71 is located higher than the rainwater outlet 73a (the inlet of the rainwater storage section 6) of the second vertical pipe 73.

A drain pipe 8 that extends vertically from the upper part 2a to the lower part 2b inside the low-rise building 2 is connected to the drain outlet of the rainwater storage section 6. The lower part of the drain pipe 8 is connected midway through the pipe so that the drained rainwater W rotates the water turbine of the hydroelectric generator 5. In other words, the hydroelectric generator 5 is installed vertically below the outlet of the rainwater storage section 6. The drain pipe 8 extends further beyond the hydroelectric generator 5, and the rainwater W after power generation is discharged at an appropriate drainage point. Note that the hydroelectric generator 5 does not have to be directly below the outlet, as long as it is located below the height of the outlet of the rainwater storage section 6.

As shown in FIG. 2, when there is no rainfall, the first head 71c in the first vertical pipe 71 and the rainwater outflow section 73a of the second vertical pipe 73 are at the same height, and the movement of rainwater W3 in the collection pipe 7 is stopped.

On the other hand, during rainfall, as shown in Fig. 1, rainwater W3 that has fallen on and accumulated on the upper part 3a of the high-rise building 3 moves from the upper part 3a of the high-rise building 3 to the rainwater storage section 6 without power due to the head difference between the rainwater inlet section 71a of the first vertical pipe 71 of the collection duct 7 and the rainwater outlet section 73a of the second vertical pipe 73. Rainwater W2 that has fallen on and accumulated on the upper part 2a of the low-rise building 2 is sent to the rainwater storage section 6 by a roof drain (not shown). In this way, the rainwater W2 and W3 that have fallen on both the low-rise building 2 and the high-rise building 3 are collected in the rainwater storage section 6.
The rainwater W stored in the rainwater storage section 6 can flow down by gravity through the drain pipe 8 to rotate the water turbine of the hydroelectric generator 5 to generate electricity.

Here, an example of the generator output of the hydroelectric generator 5 is shown. For example, assume that the site dimensions of the high-rise building 3 are 60 m x 60 m and the height is 30 m, and the site dimensions of the low-rise building 2 are 90 m x 120 m and the height is 15 m. In this case, the generator output P (kW) when rainwater is allowed to flow down by gravity at a flow rate Q ( ^m3 /s) from the effective head H (m) is calculated by the formula 9.8 x H x Q x σ, where σ is the turbine efficiency and the generator efficiency. If the hourly precipitation rate is 10 mm/h, the power generation output P is 5.88σkW.
Furthermore, when the high-rise building 3 and the low-rise building 2 each generate electricity independently (when each of the buildings 2 and 3 is provided with a drainage pipe and a hydroelectric generator), the power generation output of the high-rise building 3 will be 2.94 σkW, and the power generation output of the low-rise building 2 will be 4.41 σkW.

In this way, if the power output obtained by the high-rise building 3 is small, it is considered that installing a small hydroelectric power generation facility in the high-rise building 3 is not profitable. In other words, power cannot be generated by the high-rise building 3 alone, and only the low-rise building 2 generates power. Therefore, the power output obtained by transferring the flow rate of the high-rise building 3 to the low-rise building 2 and generating power as in this embodiment is greater.

Next, the operation of the rainwater utilization power generation system 1 described above will be described in detail with reference to the drawings.
In this embodiment, as shown in Fig. 1, in the rainwater collection facility 4, rainwater W2, W3 that falls on the upper parts 2a, 3a of the low-rise building 2 and the high-rise building 3 is collected by passing it through a collection pipe 7 to a rainwater storage section 6 provided in the upper part 2a of the low-rise building 2. Furthermore, in the rainwater utilization power generation system 1, the rainwater W stored in the rainwater storage section 6 is allowed to flow down naturally to generate power using a hydroelectric generator 5. In this way, by increasing the flow rate of rainwater used for small-scale hydroelectric power generation, the energy of the rainwater can be effectively utilized, and the power output by the small-scale hydroelectric power generation can be increased.

In addition, in this embodiment, the rainwater storage section 6 provided on the upper part 2a of the low-rise building 2 is at a lower height than the upper part 3a of the high-rise building 3, so that when the rainwater W3 that has fallen on the high-rise building 3 is made to flow into the rainwater storage section 6 of the low-rise building 2 using the collection pipe 7, collection can be performed using the head difference. In this way, in this embodiment, even in a low-rise building (low-rise building 2) or a building (high-rise building 3) in which a sufficient flow rate for power generation cannot be secured (rainfall area is small), the rainwater W2 and W3 that has fallen on each building 2 and 3 can be collected to increase the power generation output, so a sufficient amount of power generation can be secured.

In addition, in this embodiment, the collection pipeline 7 that utilizes the head difference can be placed inside or along the building, and the pipeline between the low-rise building 2 and the high-rise building 3 can also be laid above ground or underground, making it possible to realize a good landscape that harmonizes with the buildings.
Furthermore, since the power generation equipment can be placed only near the low-rise building 2 among the multiple buildings, there is no need to install power generation equipment in each building, and a good landscape that harmonizes with the buildings can be realized.

In addition, in this embodiment, the low-rise building 2 in which the rainwater storage unit 6 is provided is lower in height than the high-rise building 3, so the rainwater storage unit 6 can be installed in the upper part 2a of the low-rise building 2. Then, when the rainwater W3 from the high-rise building 3 is caused to flow into the rainwater storage unit 6 using the collection pipe 7, collection can be performed by utilizing the head difference. In other words, even if the low-rise building 2 and the high-rise building 3 are far apart, the rainwater W3 can be efficiently collected in the rainwater storage unit 6 of the low-rise building 2 without power.

Furthermore, in this embodiment, the collecting pipe 7 installed between the buildings 2 and 3 is configured to pass through the ground surface or underground, so that the layout can be planned to take into consideration harmony with the buildings, and damage to the building's scenery can be prevented.

As described above, the rainwater power generation system according to this embodiment can generate power by effectively utilizing the energy contained in rainwater, and can also improve the appearance of the building.

The above describes an embodiment of the rainwater utilization power generation system according to the present invention, but the present invention is not limited to the above embodiment and can be modified as appropriate without departing from the spirit of the invention.

For example, in this embodiment, two buildings (low-rise building 2 and high-rise building 3) are the target, but it is sufficient that the rainwater that falls on the upper parts of multiple buildings is collected in the rainwater storage section 6 of one building through collecting pipes 7 and 7A, and it is also acceptable to have a configuration in which three or more buildings are connected by collecting pipes.

In addition, in this embodiment, at least one of the multiple buildings, a first building (low-rise building 2), is set to a lower height than the other second building (high-rise building 3), and a rainwater storage unit 6 is provided in the first building. In this case, rainwater from the second building can be moved to the first building by circulating it through the collection pipe 7 without power, but this is not limited to a configuration in which there is a height difference between the multiple buildings. In short, it is sufficient that the rainwater storage unit 6 is located at a lower position than the tops of the multiple buildings, and it does not matter if the multiple buildings are the same height.

In addition, in the embodiment, the horizontal pipe 72 of the collection pipeline 7 that is laid between the low-rise building 2 and the high-rise building 3 is configured to pass through the ground surface or underground, but the pipe is not limited to this position, and may be installed at a height above ground level that allows people and vehicles to travel underneath, for example, as long as it does not cause any aesthetic problems.

Furthermore, the shape and size (capacity) of the rainwater storage section 6 can be appropriately set according to conditions such as the amount of rainwater collected from multiple buildings.
In addition, the installation location of the rainwater storage unit 6 is shown as an example to be located on the roof (upper part) of a building (in this embodiment, a low-rise building 2), but is not limited to this location, and the rainwater storage unit 6 may be provided, for example, at the upper part of the building on the top floor of the low-rise building 2.

The rainwater utilization power generation system 1, 1A described above may be installed as a retrofit to an existing building, or may be constructed in a newly constructed building by incorporating the collection pipeline and rainwater storage unit in advance.

In addition, the components in the above-described embodiments may be replaced with well-known components as appropriate without departing from the spirit of the present invention.

1, 1A Rainwater utilization power generation system 2 Low-rise building (Building 1)
2a Upper part 3 High-rise building (2nd building)
3a Upper part 4 Rainwater collection equipment 5 Hydroelectric generator 6 Rainwater storage section 7, 7A Collection pipe 8 Drain pipe 71 First vertical pipe 72 Horizontal pipe 73 Second vertical pipe W, W2, W3 Rainwater

Claims (2)

A rainwater power generation system that generates electricity by using rainwater that falls on the top of a building,
A rainwater collection facility that collects rainwater that has fallen on an upper portion of a plurality of buildings via a collection pipe into a rainwater storage unit provided on an upper portion of any one of the plurality of buildings, a first building;
A hydroelectric generator provided below the rainwater storage section and configured to generate electricity using hydraulic power of rainwater naturally flowing down from the rainwater storage section;
Equipped with
The rainwater storage unit is disposed at a position lower than an upper portion of at least a second building other than the first building among the plurality of buildings ,
The collection pipe connected to the upper part of the second building and the rainwater storage section of the first building,
A first vertical pipe arranged from an upper portion to a lower portion in the second building;
A horizontal pipe passing through the ground surface or underground between the second building and the first building;
A second vertical pipe that is piped vertically upward from a lower portion of the first building to the rainwater storage section;
having
A rainwater utilization power generation system , characterized in that the hydroelectric generator is installed in the first building . 2. The rainwater utilization power generation system according to claim 1, wherein the upper part of the first building and the upper part of the second building are the rooftops of the first building and the second building, respectively .

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