STREAM VALUE.pdf

7/27/2019 STREAM VALUE.pdf

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The story of STREAM value

The technical and functional explanation of Ultra Low Headhydro power system STREAM

2013

Seabell International Co., Ltd.


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1

Categorization of small hydro power generation

General overview of small hydro power system

(1)The definition of small hydro power systemSmall hydro power system in new and renewable energy is usually defined as less than 1000kW, but an universal standard definition

does not exist. Generally, 1,000 to 10,000kW is small hydro, 1,000 to 100kW is mini hydro, less than 100kW is micro hydro. Output of

less than 1 kW is pico hydro. (collectively small hydro power or micro hydro power is used.)

Two generating methods of small hydro powersmall hydro power system can be broadly categorized into two systems bypass method and open canal method.

Its important to know the difference between the two methods.

Bypass methodGenerating electricity by constructing by-

pass pipe only for the purpose of hydro

power generation from the river, canal or

reservoir and the generator installed bottomof the head drop.

Open canal methodGenerating electricity by installing

generator in existing canal and use its head

drop or slope without penstock.

headdrop

generator

intake weir

screen

by-pass

pipehead

drop(slope)

generator

screen

quantity of water intake is stablehead drop doesnt change no harm to river and canal by using by-pass pipeneed screenthose requirements are needed for installation. So

the installation sites are limited and the cost of civil

work is expensive.

quantity of water intake is not stable head drop, water level, and velocity are changedexisting river and canal is not for the purpose of

generating power. So, hydro power system must not

harm its function.

the shape and function of hydro power system should

requires security of canal function and correspondwater volume variation, head drop variation and dust.


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Bypass methodGenerating electricity by constructing by-

pass pipe only for the purpose of hydro

power generation from the river, canal or

reservoir and the generator installed bottomof the head drop.

Open canal methodGenerating electricity by installing

generator in existing canal and use its head

drop or slope without penstock.

headdrop

generator

intake weir

screen

by-pass

pipehead

drop(slope)

generator

screen

quantity of water intake is stablehead drop doesnt change no harm to river and canal by using by-pass pipeneed screenthose requirements are needed for installation. So

the installation sites are limited and the cost of civil

work is expensive.

quantity of water intake is not stable head drop, water level, and velocity are changedexisting river and canal is not for the purpose of

generating power. So, hydro power system must not

harm its function.

the shape and function of hydro power system should

requires security of canal function and correspondwater volume variation, head drop variation and dust.


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(2)General category of turbine

impulse water turbinehead drop 10-200mthis is the wheel to generate electricity by using the waterjet from the nozzle to spin the wheel.

Pelton wheel cross flow wheel turgo impulse wheel

reaction water turbinehead drop 2-100mthis is the wheel to generate electricity by using water pressure from the penstock impinging on the blade of wheel and rotate it.

fransis wheel propeller wheelkaplan wheel tubular wheel undershot water wheel


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gravity water wheelhead drop110mthis is the wheel to generate electricity by the water weight in the water pan to rotate turbine.

overshot water wheel spiral water wheel

General applying map for small hydro generation vs stream

Guide book for micro hydro generation(2003) by NEDO Untapped water-power resources research by NEF

basically, conventional hydro power generation systems require 10 to 200 m head drop for its practicalfunction. And generally, it generates more than 100 kW for its costeffectiveness.

2 m head

2 m head

Optimum range of

conventional type

Optimum range for stream

Optimum range of

conventional type


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1 STREAM is a combination of four technologies

5

STREAM can provide high efficiency and adaptability based on four technologies.

why STREAM can generate power at the ultra low head open canal?general misunderstandingConventional hydro power generation system that utilize high head drop is totally different from hydro power generation

system for open canal such as agricultural canal are totally different in technologies, functions, and system. Those are

categorized in same system and theory, but actually its features and functions are not the same.

Four technologies of STREAM for generating electricity in open canal

hydraulics-----the shape of turbines/fluid technology)

utilization of water-----adaptive technology of features,functions, and facilities of canal

operation-----technology for change of streamflow and sitecondition and trash

manufacturing-----cost reduction and easy maintenance bystandardadization


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1-1 The hydraulics

6

the shape of turbines/fluid technologyCaution! before the exposition of stream turbineIt is said that the turbine for hydro power system is similar to that of wind turbine. But actually, characteristics of

wind energy and hydro energy is different. Both are kinetic energy. However water is noncompressed body and it

can be converted into potential energy. Meanwhile, wind doesnt have any concept of potential energy and it does

not possess viscosity with relatively low friction. There are three types of turbines, impact type, reaction type, and

gravity type, each turbine having its own application range. Especially in low head environment, effective head is

important.

STREAM turbine;converts maximum energy at the center of water flow in canal into generatingenergy by the dual axis cross flow turbines.

incorporates both impact type and reaction type, structure with reservoir, orificehole, and vertically placed numbers to achieve high generating efficiency.

function include guiding vanes adjacent to the runners enabling adjustment ofwater intake and effective head.

has dual axis structure which is more compact than single axis structure of thesame output.(60-70% dimension) Dual axis enables variation including using only

one runner thus optimizing output based on current intake level.


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1-1 hydraulics

7

Control

gatecanal

Fixed guide Dual axis cross flow

Bell mouth shapeOrifice hole

Guide vane

Maximum energy

working point

Maximum length point

from center of axis

Pressurized

intakeFree discharge

Impact/reaction

centralizedMaximum energy

Flowing

water

PressuredDecreased

speed-up

Open/

discharge

Impact/

reaction

Wide open

Water movement

canal control gate Bell mouth Orifice (blade/rotation energy open/diffusion


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1-1 hydraulics

8

STREAM

Undershot Water WheelCross flow turbine

Control gate

Original water flow

Control water level by guide vane

diffused

Diffused effective

head

Quick discharge

STREAM

Original effective head

Operating effective head

Stable flow of water

Maximum effective

head


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1-1 hydraulics

9

Rainy Season

Dry season

Water volume Q

Water volume Q2

H

Guide vane: controlled

It can keep same effective head level in any season by controlling guide vane.

H

Water volume Q

Water volume Q

Guide vane: full open

Orifice full open

Control orifice hole

orifice velocity

V m/sec

Actual effective head

orifice velocity

V m/sec

Actual effective head


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1-1 hydraulics

Same water volume

Length of housing LLength of housing L2

Dual axis has advantages in turbine diameter and size of housing compared to single axis

even if the water volume for operating(=orifice area * orifice velocity) is same. Also, it can

change orifice area by controlling guide vane.

Efficient and Compact StructureCross flow turbine STREAM vertical single cross flow turbine

Same orifice area

Canal width

Same

water

volume

Same

orifice

area

Same

orifice

area

Same

orifice

area

Same

orifice

area


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adaptive technology of features, functions, and facilities of canalcaution before the exposition of stream turbine

the major function of open canal is streaming. Producing power in the canal has a possibility to disturb its

function. This is the important point to produce power in the canal. Generating power in the canal means it will

take the energy of stream. So, generating power in the canal requires a hydro power generating system which

can maintain canal functions and use limited resources.

STREAM turbine has,

the feature and functions which can maintain the canal function and optimizeallowance ability of canal. It can control water volume and upstreams water level

by the guide vane. Also, the control gate at upstream can control water level and

overflow the water when its rainy season. STREAM is the hydro power generation

system which can adjust itself in each different canal condition to generate power.

2 utilization of water


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2-1 utilization of water

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limited water level

water level in rainy season

original water level(irrigation season)

original water level(non irrigation season)

STREAM power generation at very low head

water level after installation

original water level in rainy season

limited water level80% water level



original water level

Water condition

after installation

Water condition

before installation

Rainy season

Original

No change in water condition will happen after STREAM installationat very low head.Cross-section of canal water condition after STREAM installation

limited water level


original water level(irrigation season)

original water level(non irrigation season)

B

A

Before installation After installation

No change in canal function

Effective head


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the height of sidewall



water level of reservoir

A point B point

A point

B point

Rainy season

Original water level(irrigation season)

Original water level(non irrigation season)

Water condition after installation

Water condition before installation

STREAM power generation with no head drop(= water flow)

Limited water level

Rainy season

Irrigation season

Non irrigation season

Bed level

Rainy season

Irrigation season

Non irrigation season

Bed level

Limited water levelsidewall

sidewall

2-2 utilization of water

allowance height

Effective head

allowance height

allowance height


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3 Technology for corresponding streamflow change,

conditioned change and trash in the canal

caution before the exposition of stream turbineThe agricultural canal and drainage canal is not for the purpose of generating electricity. The streamflow in the

canal can be changed in every season and there are lots of trash. Even if the conventional hydro power system

has high efficiency, if it doesnt correspond to the streamflow change or trash problem, its not better solution

To generate electricity in the canal. If they installed attached structure such as intake gate or dust eliminator,

the maintenance cost will be increased and its operational condition will be worse. As a result of those attached

structure, its too difficult to reach annual energy production.

STREAM has dual axis structure which can go through flotage such as trash and fallen

leaves to the down stream and that can save maintenance cost and increase operational rate.

General hydro power system such as propeller type, overshot water wheel, cross-flow turbine

has difficulty to correspond to external factors such as trash. So they require attached structure

and it increases cost.

STREAM has a sector form gate to control water level and water volume by itself.

So, it can correspond to 30 to 100% streamflow change between irrigation period and

non-irrigation period.

3 operation


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Feature of dual axis turbine for trash

Propeller type trash will entangle in each blade

flotage

Blade looks toward upstream Blade looks toward downstream

Half-turn

3-1 operation


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STREAM

Single Turbine

Strong discharge power

Guide vane

Weak discharge power

Like a pitching machine, both turbines rotate

and scrape out trash and other obstacle.

Feature of dual axis turbine for trash

3-2 operation


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Both sides fixed bearings for foreign matters and mudguard for bearing

Bearing

Bearing

Gear

mudguard

mudguard

Its easy to prevent small trash and sand toenter into under-bearing.

mudguard

trash, sand, branch

Additional strength

medium plate

Additional strength

medium plate

3-3 operation


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Wide range of operation by dual axis turbines and guide vane.

Both axis operation

100% open

Both axis operation

70% open

Single axis operation

50% open

Single axis operation30% open

Both axis stopfor maintenance

100% 70%50%

30%

3-4 operation

Discharge from

control gate


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cost reduction and easy maintenance by standardizationcaution before the exposition of stream turbine

conventional hydro power generation system requires ancillary works or civil works such as penstock, water

intake facilities, dust removal device, and foundation work. Thats why all system are custom-made at each site

and usually those ancillary works or civil works cost are more expensive than machine cost.

STREAM turbine

achieve cost reduction by standardization of each model and use general parts.can adjust itself in various canal condition by the fixed guide and control gatewith rise and fall system and different water condition by guide vane.

can be installed in a few days after setting up fixed guide such as 2 or 3 days forinstalling control gate, turbines, control panel, and power distribution work and 1

day for commissioning.

can stop passing water through itself by the guide vane and maintain itself easily.For part replacement or periodic replacement, its easy to maintain out of water by

using rise and fall system. Also, its easy to replace the location.

4 manufacturing


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Generalized generator

Generalized gear

Turbine: SUS304 Generalized bearing

Generalized bearing

Body: steel(galvanizing)

Cost reduction by minimum number of parts and general parts

STREAM is the unitized system by using minimum parts and

general parts and it can be installed in different type of

location.

Turbine, gear, generator

Control Panel

4-1 manufacturing


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Cost reduction by standardization

Its not custom-made. All models are all in one unit andstandardized by output. So, its possible to install it in variouscanal condition.

4-2 manufacturing

Canal width Canal width

Standardization of

size and shape Standardization of

size and shape


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Requires a few days for installation

Fixed guide

Control gate

(removable)

sidewall

BodyAnchor bolt

fixed guidecontrol gatebodyEach part is unitized and easy to

install. No civil work required. 2 or

3 days required from installation to

commissioning.

4-3 manufacturing


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Easy maintenance, local repair and parts replacement

Stop the passing water through the

machine by closing the guide vane.

Discharge water from

the control gateThe water level will be the original level after remove STREAM.

Its possible to remove or replace

STREAM in an emergency.

Easy maintenance in canal Easy repair

4-4 manufacturing

Cleaning and maintenance

is possible after stop the operation.

Lift up

Easy repair at the site.


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5 Wildlife Animal Protection

Preventing wildlife animals such as fish from entering intosystem is important socially as well as for power efficiency.

STREAM VALUE.pdf

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