NEW HYDROPOWER WATER WHEEL
PATENT WO 2004/048773
The
water wheel was invented thousand of years ago in Mesopotamia. In the
Middle Age, many mills were born in whole Europe. The water wheel
run-off by under, by over, by side, etc... ensured the driving force
needed for the wheel rotation.
No mill was able to use the water
height pressure of natural or man-made dams.
CONTEXT
Although
hydropower is recognized as a renewable energy and without CO2
emissions, it is confronted with many ecological oppositions because
of its impacts on the environment.
The integration of hydropower
in green electricity products is consequently a very difficult
task.
It is this report which led to the design of a new water
wheel, of slow revolution speed, associated with a dam, and non
destructive of aquatic ecosystems.
It is a dam paddle water wheel,
for low drops (from 1 to 5m), capable of producing between 20kW and
1000kW, easy to build, and easy to implement in new sites or in
replacement of old abandoned mills
It is a concept that can be
considered as a soft and ecological micro-hydropower for production
of green electricity.
HISTORY
In the XIXth century, in
France, nearly 100000 water wheels were in activity, and we did not
count the many wheels present all over the world.
With the
industrial development, most of them were abandoned and replaced by
high speed turbines which were the only ones capable of using the
water height pressure of dams.
This technique was used so far
with the development of hydraulic electric power
However today,
although hydraulic electricity is recognized as durable, and without
CO2 emission, it is sometimes confronted with an ecologic opposition
due to its major drawbacks: dams destroy whole valleys, and turbines,
whatever the height of the dams, even in low falls, destroy the
aquatic environment. In addition, external installations needed to
make the turbines work are heavy and expensive, and raise
considerably the cost prices of the low drops
All kinds of paddle
wheels existed: by over, by under, by side, etc... The most
sophisticated was the SAGEBIEN wheel , invented in the XIXth century.
Their use was then considerably reduced, no paddle wheel could use
the totality of water height potential energy.
THE
TURBINE FONFREDE
The old paddle wheels did not use much of the
available heights. The water paddle turbine makes it possible to use
the water height without calling into question the original rights
(flows and canals).
The mobilization of the water height changes
considerably the economic situation of these old sites, by improving
them. Indeed, the energy production is maximum and several times
better than that of origin, without any changes of the old data.
This opens the way to the economic rehabilitation of these sites,
and the inheritance conservation. The figure shows an example of
replacement, by this turbine, of an old paddle wheel, in an old site
where the water height was not mobilized.
The production should
be around 80kW, which allows the economic rehabilitation of the
site.
INNOVATION
It is this report which led to the
design of a slow rotation speed paddle turbine, harmless for the
aquatic environment, whose simple design makes it possible to propose
standards (from around 20kW to 1000kW), and easy to implement, thus
opening the way to an ecological alternative for the hydraulic power
production, for low drops (from 1 to 5m), most of them not being used
at present.
For example, 10000 drops of around 1m existed in the
XIXth century in the country of the Loire.
The present turbine
works with a new type of paddle water wheel which we could call dam
paddle water wheel. It allows for the first time the integration of a
fixed dam in the wheel and therefore the use of the totality of water
height potential energy, without imposing any restraints on the
natural flow.
DESCRIPTION
Many
alternatives of manufacture are possible.
The innovation consists
in reducing the volume needed to the paddles displacement to its
minimum, i.e. the envelope of the cylinder used by the passage of
paddles.
This allows to have an interior volume available for the
installation of fixed parts, making up a dam .
The lower part of
this dam acts as a the higher wall for the paddles passage.
The
paddles have an hydrodynamic shape in order to have the minimum of
resistance entering the water by developing favorable hydrodynamic
forces in the meaning of the wheel rotation direction.
The only
hydraulic losses are the losses of the flow escape due to the
manufacture precision.
The fixed parts allow to place the devices
of multiplication and gear box needed to the drive of the electric
generator, thus reducing the usually reserved external arrangement
for this purpose.
The regulation is made, as with modern wind
generators, by a disc brake which allows to stop the wheel.
When
the wheel is stopped, water does not flow and the wheel acts as a
closed valve. This device can so permit the use of tides energy in
two directions of flow.
The axis, made of a high strength metal
tree, has a very important function of maintaining and precision of
the whole by the means of bearings.
Manufacture can varyÊ:
the wheel diameter, its width, the paddles height and the water
height are directly linked with the use parameters of the river or of
the water reservoirs.
Water height can range from 0.5m to 5, or
more. Manufacture of the elements, including the paddles, due to
their shape, is very simple and economic, with few external
expenses.
Produced energy is function of two parameters,
constituted by the two different assembled elementsÊ: the
rotating disc, dimensioned by the water height, and the paddles,
dimensioned by the flow. It is so possible, by combining these two
elements, to answer with standards (a combination of two standards)
to many variations of energy production, as with the others elements
of the whole turbine (multiplication, generator).
It can be
useful for controlling the costs.
The design makes it possible to
be freed from the heavy constraints of hydroelectric installations,
with a simple and quick installation, after earthwork, of some
sub-assembled hydro-generator parts, characterized precisely.
This
opens a totally new equipment field with the use of lower flows and
levels, and this for low equipment and exploitation costs.
DESIGN
ANALYSIS AND FLOW CALCULATION
The performance analysis of the
micro-hydro turbine is realized in collaboration with CREMHyG and
LEGI, two Laboratories of the INP Grenoble University
(France).
Global simulations taking into account the river
free-surface flow are developed and used to optimized the inlet and
outlet of the turbine. Design aspects as well as through-flow in the
paddle wheel are also studied with commercial software.
The final
objective is to ensure reliability and efficiency with an
easy-to-manufacture design.
These figures illustrate a model of a
dam paddle wheel which will be tested with different configurations
to optimize the hydraulic design.
ENVIRONNEMENT
AND ECOLOGY
This device is perfectly adapted to low-cost
micro-economy development, within the framework of ecologic and
durable energies.
Water circulation and flow rates stay in the
framework of natural flows, paddles shapes and distance between them
allows the passage of alive species without any damage, thus
answering to fishermen concerns and to ecological protections.
It
also let pass the majority of objects going with the flow.
Only
protective grates with large mesh are necessary to block bigger
objects.
This reduces all the more maintenance costs.
The
arrangements remain in aesthetic optics of the traditional paddle
wheels and consequent infrastructures are reduced to the minimum.
