WATER FLOW TURBINE

TURBINE HYDRAULIQUE

English Abstract

In a device to generate power from flowing water, the water flows inside the host body (6) of the turbine and rotates the rotor (2), which rotates an electrical generator (10) to produce electricity. The Water Flow Turbine converts the kinetic energy in the flowing water into electrical energy. A mathematical derivation shows that power can be magnified by funnelling. This magnification of the power is proportional to the square of the ratio of the inlet area (1L or 1R) of the host body (6) to the area of the rotor (2) projected area. This magnification of power implies smaller size rotors, which reduce the cost and mechanical problems associated with rotation. Flow director (7) is used to direct the flow when reverses, instead of directing the whole underwater turbine. This device belongs to tidal power, and can work either for unidirectional flow or oscillatory flows.

French Abstract

Un dispositif qui génère de l'électricité par l'écoulement de l'eau, l'eau coule dans la structure réceptrice (6) de la turbine et fait tourner le rotor (2) qui à son tour fait tourner un générateur d'électricité (10) pour produire de l'électricité. La turbine à écoulement d'eau convertit l'énergie cinétique dans l'écoulement d'eau en une énergie électrique. Une dérivation mathématique montre que l'énergie peut être intensifiée par canalisation. L'intensification de l'énergie est proportionnelle au carré du rapport de la superficie de la section d'entrée (1L ou 1R) de la structure réceptrice (6) par la superficie de la zone de projection du rotor (2). L'intensification de l'énergie présuppose l'utilisation de rotors de petite taille qui réduisent les coûts et les problèmes mécaniques associés à la rotation. Le guide d'écoulement (7) sert à orienter l'écoulement lorsque celui-ci change de direction, au lieu de diriger toute la turbine sous l'eau. Ceci est un dispositif d'énergie marémotrice et peut fonctionner avec un flux unidirectionnel ou des flux oscillatoires.

Claims

Claims
The following are the claims of the present invention and they are kept open
for future
modifications:
1. A stand-alone, self-contained, transportable, water flow turbine,
comprising a host body, a
first inlet and a second inlet, the first inlet and the second inlet located
opposite to each
other on each side of a rotor, where the water current flows through the first
inlet or the
second inlet and accelerates toward the rotor, said rotor rotates in a
horizontal plane, said
rotor is fixed to a lower end of a vertical shaft, said shaft is supported by
bearings, said shaft
has an upper end that is connected to a mechanical transmission means, said
mechanical
transmission means is connected to a generator, a flow director directs the
flow upward
toward said rotor, whether the flow comes through the first inlet or the
second inlet, said
flow director has an axis of rotation that is perpendicular to the axis of
said shaft, said flow
director directs the flow upward, towards said rotor, whether the flow comes
from the first
inlet or the second inlet, after delivering some of its kinetic energy to said
rotor, the water
current flows through a first opening or a second opening, the first opening
and the second
opening located opposite to each other on either side of the rotor in said
host body, the
water flow leaves said host body by pushing a first gate or a second gate, the
first gate opens
and closes the first opening and the second gate opens and closes the second
opening,
according to the direction of the water flow, said water flow turbine contains
a generator
control gear and a protection equipment against sea creatures.
2. Said water flow turbine as claimed in claim 1, wherein the water flow
turbine is laid on the
seafloor.
3. Said water flow turbine as claimed in claim 1 or claim 2, wherein the water
flow turbine
operates at low current speeds of about 2m/s.
4. Said water flow turbine as claimed in any one of claims 1 to 3, wherein
said host body is
constructed in a way that enables funnelling of the water flow as the water
flow proceeds
from said first inlet or second inlet toward said rotor.
5. Said water flow turbine as claimed in any one of claims 1 to 4, wherein
said host body is
constructed of a type of material that resists the corrosive effects of salty
water.
9

6. Said water flow turbine as claimed in any one of claims 1 to 5, wherein
said protection
equipment comprises nets that cover the first inlet and the second inlet to
filter the water
flow.
7. Said water flow turbine as claimed in any one of claims 1 to 6, wherein
said protection
equipment comprises nets covering said first opening and said second opening
to prevent
objects from entering said first opening and said second opening.
8. Said water flow turbine as claimed in any one of claims 1 to 7, wherein
said rotor is made of
a type of material that resists the corrosive effects of salty water, and
wherein said rotor is
covered with a ceramic layer.
9. Said water flow turbine as claimed in any one of claims 1 to 8, wherein
said rotor is a
propeller type rotor.
10. Said water flow turbine as claimed in any one of claims 1 to 9, wherein
said bearings are
magnetic bearings.
11. Said water flow turbine as claimed in any one of claims 1 to 10, wherein
said generator
delivers DC or AC electrical power.

Description

CA 02489946 2007-12-05
Applic. No.: 2,489,946 Water Flow Turbine
Owner: Mina, Kameal
Description
This device is called "Water Flow Turbine (WFT)" or "Underwater Turbine (UT)",
as it will
be completely submerged in the flowing stream of water, except for the
electrical part. The
purpose of the Water Flow Turbine is to generate power by converting the
kinetic energy in the
flowing water into electrical energy. This device belongs to power generation
that is based on
renewable sources of energy, specifically from tidal currents.
Many of the existing underwater turbines (also known as marine current
turbines) do not
use funnelling system to magnify the flow power. Some of them require a 180
rotation to face
the flow when reverses its direction. Huge, complicated and expensive systems
were developed
earlier. Some of earlier systems utilize the potential energy of the tide,
which is irregular and
unsteady in nature. The kinetic energy contained in the tide is believed to be
more steady and
reliable (the tidal wave period is approximately 12 hours in the Atlantic, for
example). Other
systems use the fluctuating water level to compress air, which spins turbine
rotors. It is
understood that compressed air loses energy in the form of thermal energy, due
to its
compressibility. The idea of generating electricity from the flowing water is
described as
follows:
1. Flowing water is accelerated through inlet (1L) or inlet (1R) in the host
body (6) of
the turbine, as in fig. 1.
2. The accelerated water flow rotates the turbine rotor blades (2) in fig. 1.
3. The vertical shaft (4) rotates the mechanical transmission means (9), which
speeds
up the rotational speed of the rotor (2), as in fig. 1.
4. The power is finally transmitted from the mechanical transmission means (9)
to the
generator (10) at the designed RPM (Rotation Per Minute) and torque.
The following mathematical analysis shows, quantitatively, how funnelling can
be
implemented to magnify the available power in the flow. Consider the water
flow to be onshore
directed, from the left to the right (imagine the shoreline or the beach is to
the right of the
Water Flow Turbine), as indicated in figure 1. The power available in the
flowing water at inlet
(1L) is:
2
Signature:

CA 02489946 2007-12-05
Applic. No.: 2,489,946 Water Flow Turbine
Owner: Mina, Kameal
P, = 2 pV,3A, (1)
Where p is the water density, V, is the water velocity at section (lL) and A,
is the cross
section area at (1L). Now the power available in the flow at the rotor (2) is:
3
P2 = 1 2 pV2 A2 (2)
Where V2 is the water velocity before hitting the rotor (2), and A2 is the
rotor projected
area. The continuity equation states (considering the water to be
incompressible and the flow is
steady):
V,A, = V2A2 (3)
Substitute for
lz =V, ' (4)
A2
In equation (2):
3 2 2
P2 = 2 pVi3 ' A2 ~ pV 3 Ai ] ' = P A,)
(S)
2 z 2
Which means magnification of the power available at cross section (1L), by the
amount
2
AI
A at cross section (2), the rotor cross section. This implies smaller size
rotors, which
2
means lower cost and less mechanical problems associated with moving parts.
3
Signature:
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~~

CA 02489946 2007-12-05
Applic. No.: 2,489,946 Water Flow Turbine
Owner: Mina, Kameal
The final power delivered from the generator will be the multiplication of all
efficiencies
(mechanical and electrical) and of the power coefficient of the rotor. The
final power delivered
from the generator will be:
PG = qm'7eCPP2 (6)
Where PG is the final power delivered by the generator, r7m is the mechanical
efficiency, r7e
is the electrical efficiency and C. is the power coefficient of the rotor.
As a numerical example, assume the incoming water speed is V, = 2m / s, and
the area of
cross section (1L) is A, = 2m2. If the rotor (2) projected area is A2 =1m2 and
the water density
is p=1000kg / m3 , then the following can be calculated:
P, = 2 pV,3 A, = 2(1000X2)3 (2) = 8000watts
V2 =V, Al =2 1 =4mis
A2
P2 = ~ pVZ A2 = 2 (1 00OX4)3 (1) = 32000watts
2
P2 = 4 x 8000watts = 4P, = P, A,
(A2
Assuming mechanical efficiency of qm = 85% = 0.85, electrical efficiency of
77e = 96% = 0.96, and a rotor power coefficient of CP = 0.3, then the final
power delivered by
the generator is:
PG = rlmz7eCPP2 = (0.85X0.96X0.3X32000) = 7833.6watts
4
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Signature:
AI-1/1PI, c t"~I

CA 02489946 2007-12-05
Applic. No.: 2,489,946 Water Flow Turbine
Owner: Mina, Kameal
For an area ratio of ' = 3, the power is magnified by the factor ' =(3)z = 9,
which
2 z
means an available power of P2 = 9 x 8000watts = 72000watts at the rotor. If
the same
efficiencies are used; 77= 0.85, qe = 0.96, and C p= 0.3, then the final
generator power is:
PG= i7,nqeCPPz = (0.85X0.96X0.3X72000) =17625.6watts
The problem of the change of the flow direction is solved by the flow director
(7). The flow
director (7) rotates about an axis that is perpendicular to the rotor shaft
(4). The axis of rotation
of the flow director (7) is also perpendicular to the direction of the flowing
water current. If the
flow reverses its direction to be offshore directed, i.e. from the right to
the left in figure 1, the
flow director (7) will lean to the left due to the flow pressure in this
direction and gate (8L) will
open and gate (8R) will close, also due to the flow pressure acting to the
left. Gates (8L) and
(8R) have pivots, which are perpendicular to the shaft (4) and to the flow
direction, but parallel
to the axis of rotation of the flow director (7). Therefore, the problem of
flow reversal from
onshore to offshore or vice versa is solved in the present design.
The host body (6) can be provided with a low current, low voltage circuit to
dismiss sea
creatures and prevent them from sticking to the host body (6). The host body
can be
constructed of a type of concrete that can resist salty water. The rotor (2)
should also be
constructed form the same type of concrete used for the host body (6). The
rotor blades (2)
should also be covered with a ceramic layer to provide a smooth and strong
surface. The
number of blades of the rotor (2) can be 2, 3, 4, or any suitable number for
the design under
consideration. The rotor rotational speed can also vary and might be low or
high, depending on
the design under consideration. The rotor (2) should be propeller type,
similar to those used in
horizontal axis wind turbines.
The shaft (4) should be supported by magnetic bearings (5), in order to reduce
the frictional
losses with the shaft (4). The generator (10) can be DC (Direct current) or AC
(Alternating
Current). DC generators can be used to electrolyse water into Hydrogen, which
can be stored
and transported, and burnt under control in larger power stations. The
generator (10) can be
Signature:
y ~~ / V

CA 02489946 2007-12-05
Applic. No.: 2,489,946 Water Flow Turbine
Owner: Mina, Kameal
doubly fed induction motor. The mechanical transmission means (9) can have any
suitable set-up
ratio for the design under consideration.
The generator (10) and a control gear can be contained within the system of
the Water Flow
Turbine and include protection for faults that could be expected in systems of
this nature, where
input energy is variable with time.
Inlets (1L) and (1R) should be covered with nets to filter the incoming water
flow from
suspended material. Openings (3L) and (3R) should also be covered with nets to
prevent any
objects from entering the host body (6).
6
Signature:

CA 02489946 2007-12-05
Applic. No.: 2,489,946 Water Flow Turbine
Owner: Mina, Kameal
Brief Description of the Drawings
Figure 1 is a side view of the water flow turbine. The whole body should be
completely
submerged in the flowing water, except for the electrical parts, which should
be well isolated
from any source of water or snow.
The water is assumed to be flowing from left to right (represented by the
velocity V of the
water in figure 1). The water is accelerated through section (1L) until it
reaches the rotor (2).
The rotor (2) is fixed to the lower end of the shaft (4). The shaft (4) is
supported by bearings (5),
which could be magnetic bearings. When the rotor (2) is rotated by the flow,
the shaft (4) will
rotate as well at the same rotational speed (RPM). The shaft (4) is connected
at its upper end to
a mechanical transmission means (9), which speeds up the rotational speed of
the rotor-shaft
combination to the designed rotational speed of the generator (10). The
generator (10) is
directly connected to the mechanical transmission means (9).
After some of the flow energy is delivered to the rotor (2), the flow
continues through
opening (3R) and pushes gate (8R) to leave the host body (6) of the water flow
turbine. If the
flow reverses its direction, the flow director (7) will lean to the left and
will cause the flow to
pass from the left inlet at (1R) then by the rotor (2), then pushing gate (8L)
to leave the host
body (6) from opening (3L).
The host body (6) is to be constructed from concrete that can resist salty
water. The rotor
blades (2) can be made of the same type of concrete and can be coated with
ceramic, which
cannot be corroded by the salty water and has a very smooth surface, to
decrease frictional
losses.
No need for special digging under the seabed to fix certain foundations (which
cost too
much money) for these types of underwater turbines. The Water Flow Turbine can
simply be
laid on the seafloor.
Drawings are shown separately in the last page. Notations used in figure 1 are
described in
the following:
Fi ug re 1:
1L: Left inlet
1R: Right inlet
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Signature:

CA 02489946 2007-12-05
Applic. No.: 2,489,946 Water Flow Turbine
Owner: Mina, Kameal
2: Rotor (consists of a plurality of blades)
3L: Left opening up
3R: Right opening up
4: Vertical shaft of the rotor
5: Magnetic bearing
6: Host body of the turbine
7: Flow director
8L: Left gate
8R: Right gate
9: mechanical transmission means
10: Generator (DC or AC)
8
Signature:

Representative Drawing