JPH046810B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the most rational waterway construction method necessary for the economic development of small and medium-sized hydroelectric power generation.

Note that the penstock line referred to in the name of the present invention refers to the unpressure headrace conduit, upper water tank, and
This refers to a waterway with an improved waterway configuration that eliminates all spillways, penstocks, etc., and fulfills all of those functions.

The conventional method of laying waterways for small and medium-sized hydroelectric power generation facilities has the following three drawbacks.

The first drawback regarding the structure of the waterway is that the unpressurized waterway has a slope of about 1/1000 between the intake weir and the upper water tank installed directly above the power plant. A spillway is installed to discharge the beneficial water from the upper water tank, and a penstock is installed between the upper water tank and the water wheel directly below to drain the water. As a result, the required head difference was obtained between the water level in the upper water tank and the water level at the water outlet of the water wheel.

In this case, a reactive head that does not contribute to power generation is created between the water level of the settling basin and the water level of the upper water tank, reducing the effective head and reducing the power generation output and amount of generated power.

In addition, such unpressurized headrace channels must be installed with open channels, covered channels, etc., maintaining a uniform slope under various topographical conditions, so they are installed by detouring along contour lines and making repeated turns. As a result, the length of the waterway will inevitably become significantly longer, the survey and design will become more complicated, and the construction will involve the danger of working at heights. Under these conditions, civil engineering costs will be high. This was a contributing factor.

In addition, concrete waterways deteriorated significantly over time due to weathering, freezing damage, etc., and required large repair costs even within the legal service life.

Furthermore, foreign objects such as fallen rocks, falling rocks, and fallen leaves were mixed into the open channels, which not only obstructed water flow but also increased maintenance costs for patrolling and inspecting the waterways.

As mentioned above, the conventional configuration of waterways using unpressurized waterways has inevitably had various uneconomical and inefficient aspects.

The second drawback regarding the material of the waterway is that concrete waterways have a large inner surface roughness coefficient, resulting in a large friction head loss, and over time, algae grows and adheres to the waterway portion, increasing the head loss. In order to achieve this goal, both initial and aging power generation output and amount of power generation have been reduced.

In addition, even in penstocks, the roughness coefficient inside the pipe is large, resulting in a large friction head loss, and the inner surface of the pipe is subject to significant aging due to rust and corrosion, which causes a decrease in power generation output and amount of power generated both initially and over time. Ta.

Regarding the third drawback, the river water utilization rate, in an unpressurized headrace channel with a fixed channel gradient and a common-sense water flow cross-sectional area, it is difficult to take in more than a certain amount of river water for power generation. Unable to do so, the water overflowed the intake dam and was discharged into the river.

As a result, this method had an extremely low river water utilization rate, and the power generation output and amount of electricity generated were also low, so it was not appropriate from the viewpoint of the most economical development technology concept of maximizing the contribution of river water to power generation.

As mentioned above, the conventional waterway construction method using unpressurized headraces has the above three drawbacks as well as the impossibility of standardizing the power generation design, resulting in high construction costs, low power generation output, and low power generation. It has become an uneconomical power generation method due to the high amount of electricity and high generation costs, making it difficult to develop and commercialize small and medium-sized hydropower.

This invention aims to improve and eliminate the shortcomings of the prior art and to facilitate the most economical development of small and medium-sized hydroelectric power generation. By standardizing waterway design through organic analysis of each element of pipe characteristics, which is possible only with the penstock system consisting of pressure pipes, we have developed a waterway installation method that can significantly reduce power generation costs. The purpose is to

This invention will be explained based on drawings according to one embodiment.

To explain the structure and installation method of the penstock system in the figure, comparing it with that of the conventional system, running water is led from a reservoir 2 created by being dammed by an intake dam 1 installed upstream of a river 14, and water is taken from a settling basin 3. Then, the outer surface of the pipe component is covered with a reinforced plastic layer.
A reinforced tube with chemically and physically stable strength, consisting of a resin mortar layer for the middle layer of the tube and a reinforced plastic layer for the tube inner surface, no deterioration over time, and an extremely low roughness coefficient on the tube inner surface. Water is passed through a pressure conduit 7 made of a plastic composite pipe and guided to a water wheel 8, and after driving the water wheel, the flowing water is discharged back to the original river 14 through a suction pipe 9.

In the meantime, the conventional pressureless water conduit 4, upper water tank, surge tank 5, spillway 13, and penstock 6 shown by dotted lines are omitted.

When a waterway is constructed of a non-pressure waterway, an invalid head 12 corresponding to the gradient of the waterway is created, but the pressure waterway 7
When constructing a waterway, an effective head difference 11 contributing to power generation is obtained between the water level of the sand settling basin 3 and the water level of the water discharge surface 10 without causing this problem.

Comparing the annual cumulative amount of water intake by the penstock method and the annual cumulative amount of power generated, which is proportional to this amount, with that by the unpressure water conduit method, we can see that in the case of the penstock method, the amount of water that is The annual power generation amount is obtained using the annual water intake amount, which is calculated by integrating the flow rate of the water amount (normally 35 days water amount) to the drought amount (355 days water amount).
Normal water flow (185 days water flow) in the case of non-pressure conduit system
Alternatively, the annual amount of power generated is obtained by using the annual water intake amount that integrates the flow rate from low water flow (275 days water flow) to drought water flow (355 days water flow), so the penstock method is better than the non-pressure water conduit method. A much larger amount of power generation can be obtained in comparison.

Furthermore, when comparing the initial cost of power generation, with the penstock method, the low initial cost of power generation is obtained by dividing the low construction cost by the annual amount of power generated, but with the unpressure conduit method, the construction cost is high. Since the high initial cost of power generation is obtained by dividing the amount by the low annual power generation amount, the penstock method is the most economical development method, and the no-pressure conduit method is the least economical development method.

Regarding the standardization of power generation plans using the penstock method, first, the most economical value is set based on the effective head coefficient obtained by dividing the effective head by the total head, and the most economical value is set based on the effective head coefficient obtained by dividing the effective head by the total head.・Pipe length・Flow velocity in the pipe・
The most economical power generation design can be easily obtained using a method that standardizes design specifications such as effective head, power generation output, power generation amount, construction cost, and initial power generation cost through organic analysis of pipeline characteristics.

According to the method of installing a waterway using a hydraulic pressure conduit constructed as described above, the first drawback of the conventional technology is improved, and by using a simple survey and a standardized easy design method, It is possible to significantly reduce civil engineering costs by omitting water tanks, spillways, penstocks, etc., and it also eliminates the invalid head that inevitably occurs with conventional methods and obtains a high effective head, resulting in high power output and large The amount of power generated can be obtained.

Furthermore, the second drawback of the prior art has been improved, and the effective head is increased by reducing the initial and aging friction head loss by using a pressure pipe using reinforced plastic composite pipe with a small roughness coefficient and no aging deterioration. Therefore, it is possible to increase the power generation output and the amount of power generated.

By improving the third drawback of the prior art and configuring the waterway with a pressure pipe, the pressure pipe with a constant water flow area and pipe gradient can be used to increase the amount of water in the pipe in proportion to changes in the amount of water used for power generation. Since the amount of water flowing changes, by converting the change in the amount of water flowing into the flow velocity in the pipe,
By making it possible to effectively use the flow rate between the maximum water usage amount and the minimum water usage amount for power generation in response to changes in water intake for power generation due to increases and decreases in river flow, the river flow rate can be reduced. By minimizing overflow from the intake dam and maximizing the use of river flow, we have been able to significantly increase power generation output and amount of electricity compared to conventional systems.

In addition, the most economical power generation design can be easily obtained by standardizing the waterway design. According to the method of laying waterways using penstocks, the initial cost of power generation obtained by dividing the construction cost by the annual amount of power generated can be reduced. It can be significantly reduced compared to that of the prior art.

According to this invention, as explained above, by improving and eliminating the shortcomings of the conventional technology and by standardizing design, it is possible to easily achieve the most economical development with low construction costs, high power generation output, large amount of power generation, and low power generation cost. It is possible to improve the development economic ranking of candidate development sites and promote the development of small and medium-sized hydropower, thereby promoting the development of oil-alternative energy as Japan's energy security and rural areas with undeveloped hydropower potential. A large contribution can be made to its promotion.

[Brief explanation of drawings]

The figure is a conceptual diagram of a run-of-river waterway type small and medium-sized hydroelectric power generation facility, and shows a comparison between the configuration of the facility according to the present invention shown by the solid line and the configuration of the conventional system shown by the dotted line. In the figure, 1... Intake dam, 2... Reservoir,
3...Sand settling basin (upper water tank), 4...Unpressure headrace,
5... Upper water tank, surge tank, 6... Penstock, 7... Pressure pipe, 8... Water wheel, 9... Suction pipe, 10... Water discharge surface, 11... Effective head, 12...
...Invalid head, 13... Spillway, 14... River.

Claims (1)

[Claims] 1. A water conveyance penstock that directly connects the water intake installed on the intake dam of a canal-type small and medium-sized hydroelectric power generation facility to the water wheel located at a lower level than the water intake with a pressure pipe made of a reinforced plastic composite pipe with a small roughness coefficient on the inner surface of the pipe. A method of laying a waterway by means of a road.