Note: Descriptions are shown in the official language in which they were submitted.
CA 02934152 2016-06-27
ANGLE-ADJUSTABLE TURBINE
TECHNICAL FIELD
[0001] This relates to the generation of electrical power, and in
particular, to a turbine
that is angle-adjustable.
BACKGROUND
[0002] Electrical power can be generated from travelling fluid flows by
transferring a
portion of the kinetic energy to a mechanical device. This principle is used,
for example, in
the case of windmills and water wheels. When changing flow conditions are
experienced, it
may be desirable to alter the orientation of the elements intersecting the
flow in order to
maximize power generation. UK Patent Application No. GB 2520422 teaches a
tidal turbine
system that adjusts in response to tidal conditions. US Patent Application No.
2015/0167646
teaches a wind turbine that tilts in response to different wind flow
conditions.
SUMMARY
[0003] According to an aspect, there is provided a turbine comprising a
turbine body, the
turbine body comprising a plurality of turbine blades, the turbine body having
a shaft defining
a rotational axis, and a bottom apex, each of the turbine blades having a
lower edge, the lower
edges tapering upward relative to the bottom apex such that the lower edges
trace a convex
surface as the turbine body rotates about the rotational axis, a support frame
connected to the
shaft by an angularly adjustable connection that adjusts the angle of the
shaft relative to the
support frame, the angularly adjustable connection permitting rotation of the
shaft about the
rotational axis, and a generator powered by the rotation of the shaft.
[0004] According to another aspect, the angularly adjustable connection
may be actuated
by an actuator.
[0005] According to another aspect, the angularly adjustable connection
may change the
orientation of the convex surface traced by the lower edges of the turbine
blades.
[0006] According to another aspect, the support frame may comprise floats
to suspend at
least a portion of the support frame above a body of water and the turbine
body may extend
CA 02934152 2016-06-27
2
into the body of water.
[0007] According to an aspect, there is provided a method of generating
electrical energy
from a fluid flow travelling in a flow direction, the method comprising the
steps of installing a
turbine adjacent to the fluid flow, the turbine comprising a turbine body that
extends at least
partially into the fluid flow, the turbine body comprising a plurality of
turbine blades, the
turbine body having a shaft defining a rotational axis, and a bottom apex, the
rotational axis
being perpendicular to the flow direction of the fluid flow, each of the
turbine blades having a
lower edge, the lower edges tapering upward relative to the bottom apex such
that the lower
edges trace a convex surface as the turbine body rotates about the rotational
axis, the turbine
body being divided by a plane defined by a first axis that is parallel to the
flow direction of
the fluid flow and the rotational axis of the shaft to define a first side and
a second side of the
turbine body, a support frame connected to the shaft by an angularly
adjustable connection
that adjusts the angle of the shaft relative to the support frame, the
angularly adjustable
connection adjusting the angle of the shaft between a first position where the
shaft is
vertically oriented and a second position where the shaft is angled from the
vertical
orientation, the angularly adjustable connection permitting rotation of the
shaft about the
rotational axis, and a generator powered by the rotation of the shaft,
adjusting the angle of the
shaft between the first position and the second position to adjust the
relative volume of fluid
flow that passes along the first side of the turbine body relative to the
second side of the
turbine body, and collecting electrical energy from the generator.
[0008] According to another aspect, the fluid flow may be a body of
water.
[0009] According to another aspect, the body of water may be an ocean, and
the ang,le of
the shaft may be adjusted in response to a changing tide.
[0010] According to another aspect, the support frame may comprise floats
to suspend at
least a portion of the support frame above a body of water and the turbine
body may extend
into the body of water.
CA 02934152 2016-06-27
3
[0011] According to another aspect, the angularly adjustable connection
may adjust the
angle of the shaft between the first position, the second position, and a
third position, wherein
in the third position the shaft is angled in the opposite direction from the
second position
relative to the first position.
[0012] According to another aspect, the angle of the shaft may be
adjusted in response to
a change in the fluid flow.
[0013] According to another aspect, the angularly adjustable connection
may be actuated
by an actuator.
[0014] In other aspects, the features described above may be combined
together in any
reasonable combination as will be recognized by those skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] These and other features will become more apparent from the
following
description in which reference is made to the appended drawings, the drawings
are for the
purpose of illustration only and are not intended to be in any way limiting,
wherein:
FIG. 1 is a side elevation schematic view of a water turbine in a first
angular
position.
FIG. 2 is a side elevation schematic view of a water turbine in a second
angular
position.
FIG. 3 is a top plan view of a turbine body.
FIG. 4 is a side elevation view of the turbine body of FIG. 3.
DETAILED DESCRIPTION
[0016] A turbine generally identified by reference numeral 10, will now
be described
with reference to FIG. 1 through 4.
[0017] Referring to FIG. 1, turbine 10 has a turbine body 12 that has a
plurality of turbine
blades 14. Turbine body 12 has a shaft 16 that rotates about a rotational axis
18. Turbine body
CA 02934152 2016-06-27
4
12 also has a bottom apex 20. Each of the turbine blades 14 has a lower edge
22. Lower
edges 22 taper upward relative to bottom apex 20 such that, as turbine body 12
rotates about
rotational axis 18, lower edges 22 trace a convex surface. As can be seen,
lower edges 22,
when taken together, are generally cone-shape, although this may be modified
as will be
discussed below.
[0018] Turbine 10 has a support frame 24 connected to shaft 16 by an
angularly
adjustable connection 26 that adjusts the angle of shaft 16 relative to
support frame 24.
Angularly adjustable connection 26 adjusts the orientation of the convex
surface traced by
lower edges 22 of turbine blades 14, as shown in FIG. 2. Angularly adjustable
connection 26
may be actuated by an actuator 28. Angularly adjustable connection 26 permits
rotation of
shaft 16 about rotational axis 18. Turbine 10 has a generator 30 that is
powered by the rotation
of shaft 16. Turbine 10 may also have a transmission 31. When used on a body
of water 32,
such as a tidal body, support frame 24 may have floats 34 that suspend at
least a portion of
support frame 24 above body of water 32 and allows turbine body 12 to extend
into body of
water 32.
[0019] The manner in which the angle of shaft 16 is adjusted relative to
frame 24 may
take different shapes. For example, there may be a simple pivot point
connection about which
shaft 16 pivots to move turbine body 12 from side to side. Alternatively, as
this may results in
a lateral translation of turbine body 12, which may be undesirable, the
connection may be
more complex such that turbine body 12 remains in a relatively constant
position, such as a
connection that slides along support frame 24 as the angle of shaft 16 is
adjusted. The
connection between shaft 16 and generator 30 may need to be adjustable as
well, such as by
providing a universal joint, a sliding carriage, a telescopic connection,
etc., unless generator
is designed to move with shaft 16 as it is adjusted.
[0020] Referring to FIG. 3 and FIG. 4, an embodiment of turbine body 12
is shown. As
depicted, turbine blades 14 curve upward and outward from shaft 16. However,
it will be
30 understood that a variety of shapes of turbine blades 14 as are known in
the art may be used.
For example, turbine blades 14 may be curved in only one direction, or may be
flat. Turbine
blades 14 may be formed to have opposing blades on either side of shaft 16,
and other spacing
CA 02934152 2016-06-27
may be used. Blades 14 are angled toward each other in a chevron or angled
shape in order to
catch the current on one side when turbine body 12 is angled into a fluid
flow. Lower edges
22 of turbine blades 14 may have a different profile, such as curves, such
that, rather than
following a cone-shaped surface, turbine blades 14 follow a semi-spherical or
otherwise
5 rounded surface. This allows for the blades 14 on the other side of
turbine body 12 to be
raised out of the fluid flow, reducing their resistance as they travel around
the other side of the
turbine body 12 to re-enter the fluid flow. For example, in a stream of water,
turbine body 12
may be angled such that the various turbine blades 14 of turbine body 12
enters the water and
are pushed by the stream of water. Turbine blades 14 are then lifted out of
the stream of
water, and are rotated to the front of turbine body 12, i.e. upstream, before
re-entering the
stream of water. As such, the fluid resistance on turbine blades 14 as they
return upstream is
reduced. The angle of turbine body 12 may be adjusted to optimize the transfer
of kinetic
energy to shaft 16, based on the characteristics of the stream of water. Frame
24 may be
installed adjacent to the stream of water using various techniques, such as a
floating support
structure, cable suspension, piles, etc., with the understanding that it will
be generally
preferred to have turbine body 12 at the top surface of the stream of water.
These installation
techniques may vary depending on the type of fluid stream, which may be
different types of
water streams or other fluid flows, and on the situation in which turbine 10.
[0021] A method of using turbine 10 to generate electrical energy from a
fluid flow
travelling in a flow direction will now be described. In general, turbine
blades 14 will be
contacted by the fluid flow, which will apply a force to turbine blades 14
such that turbine
body 12 and shaft 16 will rotate. The rotation of shaft 16 generates
electrical energy, which
can be collected from generator 30. It will be understood that turbine 10 may
be used in a
variety of circumstances where a fluid flow is provided. For example, turbine
10 may be used
as a wind powered electrical generator. Use of turbine 10 will now be
described where the
fluid flow is a body of water 32. However, it will be understood that the
principles of use in
body of water 32 will be similar in other fluid flows, such as in wind
streams.
[0022] Turbine 10 is installed adjacent to body of water 32 such that
turbine body 12
extends least partially into body of water 32. Rotation axis 18 is
perpendicular to the flow
direction of body of water 32. A plane 36 divides turbine body 12, where plane
36 is defined
CA 02934152 2016-06-27
6
by a first axis that is parallel to the flow direction, and a second axis that
is the rotational axis
18 of the shaft 16. Plane 36 defines a first side 38 and a second side 40 of
turbine body 12.
Referring to FIG. 1 and FIG. 2, angularly adjustable connection 26 adjusts the
angle of shaft
16 relative to support frame 24 between a first position, shown in FIG. 1,
where shaft 16 is
vertically oriented, and a second position, shown in FIG. 2, where shaft 16 is
angled from the
vertical orientation. Shaft 16 rotates about rotational axis 18, such that the
movement of the
flow in body of water 32 continues to turn turbine body 12 in the second
position. The angle
of shaft 16 can be adjusted between the first position and the second position
in order to adjust
the relative volume of flowing water that passes along the first side 38 of
turbine body 12
relative to second side 40 of turbine body 12. The angle of shaft 16 may
adjusted in response
to a change in the fluid flow.
[0023] Turbine 10 may be used on a variety of types of bodies of water
32. For example,
turbine 10 may be installed on a body of water 32 that is an ocean, and the
angle of shaft 16
may be adjusted in response to a changing tide. Support frame 24 may have
pontoons as floats
34, and may be anchored to the ocean floor, or another anchor point such as
the shore or a
large vessel. Angularly adjustable connection 26 may adjust the angle of shaft
16 between the
first position as shown in FIG. 1, the second position as shown in FIG. 2, and
a third position,
opposite to that shown in FIG. 2. In the third position shaft 16 is angled in
the opposite
direction from the second position relative to the first position. The angle
of shaft 16 may be
such that the turbine 10 is in the second position when the tide moves in, the
third position as
the tide moves out, and the first position as the tide is changing or when
power generation is
not required. Alternatively, turbine 10 may be installed on a body of water 32
that has a
current in a fixed direction, such as a river. In this case the angle of shaft
16 may be adjusted
in response to power demands, or in order to protect the power generation
equipment. For
example, in high current situations, it may be desired to have a smaller
proportion of turbine
blades 14 in the water at any given time to prevent damage, while in lower
current situations
it may be desired to angle turbine blades 14 further into the water in order
to maximize power
generation.
[0024] In this patent document, the word "comprising" is used in its non-
limiting sense to
CA 02934152 2016-06-27
7
mean that items following the word are included, but items not specifically
mentioned are not
excluded. A reference to an element by the indefinite article "a" does not
exclude the
possibility that more than one of the elements is present, unless the context
clearly requires
that there be one and only one of the elements.
[0025] The scope
of the following claims should not be limited by the preferred
embodiments set forth in the examples above and in the drawings, but should be
given the
broadest interpretation consistent with the description as a whole.
