GB2238832A

GB2238832A - Raising water; Power generation

Info

Publication number: GB2238832A
Application number: GB9025261A
Authority: GB
Inventors: Takeo Suehiro
Original assignee: WADA SAKUMI
Current assignee: WADA SAKUMI
Priority date: 1989-12-07
Filing date: 1990-11-20
Publication date: 1991-06-12
Also published as: CA2030853A1; DE4038812A1; JPH03179172A; GB9025261D0

Abstract

There is disclosed a power generating unit for hydroelectric power generation to generate electric power by utilizing pooled water such as lake or pond. The unit includes pipes (5a-5d) each consisting of a water introducing and dropping portion, with at least one pipe at least partially submerged in water, each pipe having a certain descending slope, and a water lifting portion, running up with steep slope from lower end of the water introducing and dropping portion, and means (9 or 11) for accelerating the water flow within the pipes. The means (9) comprises pumps in the pipes, and the means (11) comprises air compressors supplying compressed air for injection into the pipes. <IMAGE>

Description

9 a C:3 3:2:2.2:3 SYSTEM FOR RAISING WATER, AND A POWER GENERATING UNIT

FOR HYDROELECTRIC POWER GENERATION This invention relates to a system for raising water and hence to a power generating unit for hydroelectric power plant where electric power is generated utilizing pooled water such as a lake or pond.

At present, electric power in Japan is supplied by atomic., thermal and hydroelectric power generation.

However, despite the objection to atomic power plants from the view-point of safety, Japan is more dependent on it at present because of the benefits in terms of cost compared with thermal and hydroelectric power generation.

In hydroelectric power generation, the energy of running water is utilized. However, there are some problems such as the extremely high cost of building dams, the difficulty in selecting the construction sites, and the problem of the evacuation of the inhabitants. Conventional hydroelectric power generation depends upon running water, and no case is known yet where pooled water, such as a lake or pond, is utilized for hydroelectric power generation.

According to the present invention. there is provided a system for raising water, so that the raised water can be employed for hydroelectric power generation, which system comprises pipes at least one of which is at least partially submerged in a body of water- and each of which includes a water introducing and descending portion having a certain descending slope, and a water lifting portion, ascending with a steep slope from the lower end of the water introducing and dropping portion; and means for accelerating the water flow within the pipes.

The ascending slope is preferably steeper than the descending slope.

1 The reason why water can be efficiently raised by the system of the present invention is not theoretically explained to a full extent. However, because the water introducing and descending portion of the first pipe is submerged in water and its tip is under pressure, while the tip of the ascending portion is under normal pressure, it appears that this pressure difference causes the water stream to run.

For a better understanding of the present invention and to show how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings in which:

Fig. 1 is a schematical, partly cross-sectional and partly.side view, showing one embodiment of scheme according t the present invention; and Fig. 2 is a schematical, partially cross-sectional and partly side view, of another embodiment of scheme of the present invention.

In the following, the preferred embodiments of this invention-will be described in connection with the drawings.

Fig. 1 is a general view of the first embodiment of this invention. Between a box structure 2, formed by a filter and placed on a base stand 1, and a first water tank 4a. placed on a base stand 3,-extends a pipe Sa supported on a steel pillar (not shown). The first pipe Sa has descending gradient of about 35 - 45 in its descending portion 6. The pipe also has a waterlifting portion 8, rising steeply near the first water tank 4a, and the-tip of the first pipe Sa terminates at its upper portion within the.first water tank 4a. Near the water introducing portion 6 of the first pipe Sa, a branched pipe 7 is connected. and the air is sent from an air. compressor 11 through that pipe 7.

Other pipes 5b, 5c and 5d are fixed respectively between the first water tank 4a and a second tank 4b, P t- between the second water tank 4b and a third water tank 4c. and between the third water tank 4c and a fourth water tank 4d. Prom the last (fourth) water tank 4d, water falls and rotates the turbine of power generator 5 10.

It is preferable that the pipes 5a. 5b, 5c and 5d are at least 40 m in lengthi e.g. 40 m - 70 m. If the length of the pipe is longer than 40 m. the diameter of the pipe must preferably be at least 10 m. If the length is shorter than this, water may stop in the pipe and not be lifted up.

The lake or pond in which the first pipe is submerged is preferably 10 m or more in depth and 200 m or more in width. This is because water in a quantity of 85 - 90 i3 is required per minute to generate electric power of about. 10.000 M. However, the unit according to the present invention is of a circulation type, and returns the water to the pond or lake when it has been used. Accordingly, a large quantity of water must be present in the lake or pond.

In the above embodiment. water is lifted up 4 times using the first pipe to the fourth pipe, and it then falls to the power generator. This may not be strictly followedi and how many times water should be lifted up may be determined according to the power to be generated. If the power to be generated is low, water may be lifted up by the first pipe and may be allowed to fall to the power generator from the first pipe.

The air compressor exerts the action to increase flow velocity of water. and it is operated or stopped according to the desired flow velocity. In other words, if the flow velocity slows down while watching the running water, the air should be introduced. When the desired flow velocity is reached, the introduction of-further air should be stopped.

1 i In the above embodiment. the air from the air compressor is introduced into the water introducing portion, while water may be introduced to the water lifting portion.

Pig. 2 shows another embodiment of the invention, where pumps 9 powered by electric cables 13, for accelerating the lifting of water, are provided on the water lifting portion.

Each pump 9 is connected between sections of the pipes of the water lifting portion and sends the water upward, which has been sent up from below.

Next, a description is given on the operation of the unit according to this invention with the above arrangement.

When tl;e valve at water inlet of the first pipe 5a is totally opened in the condition as shown in the figure, water is sucked into the first pipe Sa making a whirl. The velocity of the water sucked into the pipe Sa is 8 m/sec or more. Water drops in the first pipe 5a and is pushed up through the water lifting portion 8. It is then blown up as high was 3 m or more from water surface and is received in the first water tank 4a. Similarly, water is pushed up toward the second water tank 4b and the third water tank 4c. Finally, it reaches the fourth water tank 4d., From the fourth water tank 4d, water falls and the turbine of power generator is rotated, and power is generated. When water is circulated in this way, flow velocity is decreased. Accordingly, the air compressors are connected to all four pipes, to introduce the air into the pipes. When a constant flow velocity is reached, the air compressor is stopped. Thus, the operation and the stopping of the air compressor are repeated according to the flow velocity of water.

Vacuum conditions must be kept inside the pipes 5b, Sc and 5d because reverse flow may occur if the air - 1 enters the pipes other than via the compressors. Valves are furnished on the tips of these pipes 5b, Sc and 5d. When a certain quantity of water is stored in the tanks 4b, 4c and 4d. the valves are opened by the 5 weight of water.

As described above, it is possible to make the still water run and to generate power according to this invention. Consequently, there is no need to construct gigantic dams as in conventional hydroelectric power 10. generation, and no problem of safety is involved unlike atomic energy plants. Moreover there is no need to consume natural resources such as petroleum. and the cost is very low. The unit of this invention has many advantages.compared with conventional type power generating units.

Some power is required to operate the compressors but this can be from a low energy level source of power which, were it not for the invention, might have been wasted.

Claims

1. A system for raising water. so that the raised water can be employed for hydroelectric power generation, which system comprises pipes at least one of which is at least partially submerged in a body of water and each of which includes a water introducing and descending portion having a certain descending slope, and a water lifting portion, ascending with a steep slope from the lower end of the water introducing and descending portion; and means for accelerating the water flow within the pipes.

2. A system according to claim 1, wherein the means for accelerating water flow in the pipes is provided on the water lifting portion.

3. A system according to claim 1 or 2, wherein the mans for accelerating water flow in the pipes comprises means for introducing air by an air compressor.

4. A system according to claim 1 or 2, wherein the means for accelerating water in the pipes comprises a pump located between sections of the pipes.

5. A system according to any preceding claim, wherein the downstream end of each pipe opens into a tank which is in communication with the upstream end of the next pipe.

6. A system according to claim 5, wherein each tank is higher than any tank which is upstream of it in terms of the direction of flow of water through the tanks.

7. A system according to any preceding claim, which includes a turbine-driven generator.

8. A system according to claim 1, substantially as hereinbefore described with reference to, and as illustrated in, Figure 1 or Figure 2 of the accompAnying drawings.

Published 1991 at The Patent office. State House. 66171 High Holbom. London WC1 R 4TP. Further copies may be obtained from Sales Branch, Unit 6. Nine Mile Point Cwmfclinfach. Cross Keys. Newport. NPI 711Z. Printed by Multiplex techniques ltd, St Mary Cray, Kent.

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