U.S. patent application number 12/661566 was filed with the patent office on 2010-10-07 for in-pipe hydro-electric power system, turbine and improvement.
This patent application is currently assigned to Nothwest Pipe Company. Invention is credited to Mark Rydell Cosby, Edward Kurth, Igor Palley, Roderic A. Schlabach, Greg Smith.
Application Number | 20100253083 12/661566 |
Document ID | / |
Family ID | 42825559 |
Filed Date | 2010-10-07 |
United States Patent
Application |
20100253083 |
Kind Code |
A1 |
Schlabach; Roderic A. ; et
al. |
October 7, 2010 |
In-pipe hydro-electric power system, turbine and improvement
Abstract
A helical turbine configured to rotate transversely within a
cylindrical pipe under the power of fluid flowing either direction
therethrough is operatively coupled with a rotating machine or
generator to produce work or electricity. The twisted blades of the
turbine define a right circular cylinder when the shaft mounting
them rotates under the influence of fluid flow through the pipe. In
one embodiment, baffles are provided at least upstream of the
cylindrical turbine and within the cylindrical pipe to control flow
through the cylindrical turbine. The twisted blades of the helical
turbine are airfoil in cross section, as are the radial struts or
spokes that mount the twisted blades to the rotatable shaft,
thereby to optimize hydrodynamic flow, to minimize cavitation, and
to maximize conversion from axial to rotating energy.
Inventors: |
Schlabach; Roderic A.;
(Goshen, IN) ; Cosby; Mark Rydell; (Goshen,
IN) ; Kurth; Edward; (San Antonio, TX) ;
Palley; Igor; (Madison, NJ) ; Smith; Greg;
(Poway, CA) |
Correspondence
Address: |
ATER WYNNE LLP
1331 NW Lovejoy St. Suite 900
PORTLAND
OR
97209-2785
US
|
Assignee: |
Nothwest Pipe Company
Lucid Energy Technologies, LLP
|
Family ID: |
42825559 |
Appl. No.: |
12/661566 |
Filed: |
March 19, 2010 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
12384765 |
Apr 7, 2009 |
|
|
|
12661566 |
|
|
|
|
Current U.S.
Class: |
290/54 ;
415/208.1; 415/229; 416/223R |
Current CPC
Class: |
Y02B 10/50 20130101;
Y10S 415/907 20130101; F03B 13/00 20130101; F05B 2220/602 20130101;
Y02E 10/30 20130101; F05B 2250/231 20130101; Y02E 10/20 20130101;
F05B 2250/25 20130101; F05B 2250/241 20130101 |
Class at
Publication: |
290/54 ;
415/208.1; 416/223.R; 415/229 |
International
Class: |
F03B 13/00 20060101
F03B013/00; F03B 3/18 20060101 F03B003/18; F03B 3/12 20060101
F03B003/12; F03B 11/06 20060101 F03B011/06 |
Claims
1. A cylindrical-turbine power generating system that generates
power from the movement of fluids, the system comprising: a
rotatable turbine mounted for rotation with a shaft, the shaft
configured to be mounted for rotation between diametrically
opposing sidewalls of a generally cylindrical pipe in transverse
orientation to the long axis of the pipe, the turbine including
plural helically twisted blades defining a generally cylindrical
sweep when rotated on the shaft, and one or more baffle assemblies,
each baffle assembly including plural radially extending and
inclined baffles configured between the turbine and the generally
cylindrical pipe, each baffle assembly configured to direct a
determined volume of fluid flowing within the generally cylindrical
pipe through the transversely oriented rotatable turbine to cause
rotation of the turbine.
2. The system of claim 1, wherein two or more the baffle assemblies
are provided on either side of the turbine within the generally
cylindrical pipe, and wherein the rotatable turbine is configured
to rotate in the same rotational direction regardless of the
direction of generally axial fluid flow within the generally
cylindrical pipe.
3. The system of claim 2 further comprising: two diametrically
opposed mounts for rotatationally mounting either end of the
turbine shaft; and a generally cylindrical tee section mounted
around an access hole formed in the generally cylindrical pipe, the
generally cylindrical tee section axially aligned with the shaft,
the generally cylindrical tee section including a concave plate
characterized by an inverted spherical dome that effectively covers
the access hole, supports one of the mounts, and thereby shortens
the distance between the two diametrically opposed rotatable-shaft
mounts and thus the length of the rotatable shaft.
4. The system of claim 3 further comprising: a piece of rotating
machinery that sits on top of the concave plate, the piece of
rotating machinery mounted to an end of the shaft located within
the generally cylindrical tee section for rotation with the
shaft.
5. The system of claim 4, wherein the piece of rotating machinery
is an electric generator or the like.
6. A power generator system for use in a fluid-conveying pipe, the
system comprising: a turbine comprising: a central longitudinal
shaft configured to rotate within diametrically opposed mounts
within a generally cylindrical fluid-conveying pipe, the shaft
configured to extend substantially perpendicularly to a long axis
of the generally cylindrical pipe, a proximal end of the shaft
configured to operatively couple with a piece of rotating
machinery; a pair of mounts, a first one thereof configured to
mount a distal end of the shaft for rotation in a first circularly
cross-sectional sidewall of a generally cylindrical fluid pipe and
a second one thereof configured to mount an intermediate part of
the shaft for rotation within the generally cylindrical pipe with
the shaft extending through the second one of the mounts; and a
plurality of blade assemblies coupled with the shaft between the
pair of mounts and extending radially outwardly from the shaft, the
blade assemblies being substantially evenly spaced apart
therearound, the blade assemblies collectively defining a generally
cylindrical shape.
7. The system of claim 6, wherein each of the plurality of blade
assemblies includes a helically curved blade mounted on opposite
spokes extending radially from a central hub.
8. The system of claim 7, wherein each of the plurality of blades
has an airfoil cross section.
9. The system of claim 6, wherein each of the plurality of blades
assemblies includes a helically curved blade having an airfoil
cross section along substantially the entire length of each
blade.
10. The system of claim 9, wherein the overall shape of the turbine
is generally cylindrical.
11. The system of claim 10 further comprising: a pair of opposing
hubs coupled with the shaft at the distal and intermediate ends
thereof, wherein each blade assembly includes opposing spoke
portions radially extending from each of the opposing hubs, each
spoke portion having an airfoil cross section, and wherein each
blade assembly further includes an intermediate helically curved
and twisted blade portion extending helically between the opposing
spoke portions.
12. The system of claim 11, wherein the plural blades number three,
and wherein an angle of inclination of each of the plurality of
blades relative to a central axis of the shaft is approximately 30
degrees.
13. The system of claim 10 further comprising: four inclined and
radially inwardly extending baffles configured on at least one end
of the turbine to extend between the perimeter of the plurality of
blade assemblies and an interior of a sidewall of a generally
cylindrical pipe, thereby to route a volume of fluid in the
generally cylindrical pipe smoothly through the generally
cylindrical turbine.
14. The system of claim 13, wherein at least one of the baffles is
notched at a curved extremity where it meets the sidewall, thereby
to route a volume of fluid in the generally cylindrical pipe into a
region outside the baffles.
15. The system of claim 14 which further comprises: a pair of
opposing generally circular hubs each including plural mounting
brackets at radially spaced intervals therearound, the plural
mounting brackets mounting opposing ends of corresponding ones of
the plural blade assemblies.
16. The system of claim 9 further comprising: a generally
cylindrical pipe configured with a diameter substantially equal to
the distance between the pair of mounts, the generally cylindrical
pipe mounting the turbine for rotation therein in response to fluid
flow through the generally cylindrical pipe.
17. The system of claim 16 further comprising: an electric
generator operatively coupled with a proximal end of the shaft for
rotation therewith to produce hydro-electric power in response to
fluid flow through the generally cylindrical pipe.
18. The system of claim 17, wherein the turbine is configured to
rotate in the same rotational direction regardless of direction of
generally axial fluid flow through the pipe.
19. The system of claim 6 wherein the turbine further comprises:
opposing hub assemblies, each including a plurality of mounting
brackets for securely affixing opposite ends of the corresponding
plurality of blade assemblies to the shaft.
20. The system of claim 19 further comprising: opposing shaft
couplers for securely affixing the corresponding hub assemblies to
the shaft.
21. The system of claim 6, wherein the plurality of blades define a
nominal solidity of between approximately 15% and 50%.
22. The system of claim 6, wherein each of the plurality of blades
is inclined at angle of approximately 30 degrees relative to a
central axis of the shaft.
23. A cylindrical turbine power generating system that generates
power from the movement of fluids, the system comprising: a turbine
comprising: a central longitudinal shaft configured to rotate
within diametrically opposed mounts within a generally cylindrical
pipe, the shaft configured to extend substantially perpendicularly
to the fluid flow, with one end of the shaft configured to
operatively couple with a piece of rotating machinery; a plurality
of bearings, a first bearing configured to mount a distal end of
the shaft farthest from the generator to a first support for
rotation and a second bearing configured to mount an intermediate
part of the shaft to a support for rotation, with the shaft
extending through the second of the bearings; and a plurality of
blades coupled with the shaft between the pair of bearings, the
blades extending radially outwardly from the shaft, the blades
being substantially evenly spaced apart around the shaft, the
blades when rotated around the shaft generally defining a cylinder,
the blades being helically twisted and being characterized along
their substantial length by an airfoil cross section.
24. The system of claim 23, wherein the plurality of blades is
mounted to the shaft with radially extending spokes also
characterized along their substantial length by an airfoil cross
section.
25. The system of claim 24, wherein the number of blades is three,
and wherein each of the plurality of blades of the turbine extends
in an approximate 60 degree arc around the defined cylinder's
cross-sectionally circular circumference.
26. The system of claim 25, wherein each of the plurality of blades
of the turbine includes a uniformly sized and shaped airfoil
cross-section along substantially the entire length of each
blade.
27. The system of claim 26, which further comprises: a pair of
opposing generally circular hubs attached to the shaft of the
generally cylindrical turbine, each hub including plural mounting
brackets at radially spaced intervals around their circumference,
the plural mounting brackets mounting opposing ends of the
plurality of blades via corresponding plural spokes.
28. The system of claim 23, wherein each of the plurality of blades
extends in a helical arc around the circumference of the
cylinder.
29. The system of claim 28, wherein the plurality of blades define
a solidity of between approximately 15% and 30%.
30. The system of claim 29 further comprising: an electric
generator operatively coupled with the proximal end of the shaft
for rotation with the shaft to produce electric power in response
to fluid flow.
31. The system of claim 30, wherein the turbine is configured to
rotate in the same direction, regardless of the direction of fluid
flow.
32. The system of claim 23, wherein each of the mounts securing the
turbine shaft includes bearings.
33. The system of claim 23 further comprising: four inclined and
radially extending baffles configured on either end of the turbine
to extend between the perimeter of the plurality of blades and an
interior of a sidewall of a generally cylindrical pipe, thereby to
route fluid in the generally cylindrical pipe through the generally
cylindrical turbine.
34. The system of claim 33, wherein each of the four baffles is
inclined relative to the cylindrical pipe at an angle of between
approximately 5 and 15 degrees.
35. The system of claim 34, wherein at least one of the baffles is
notched at a curved extremity where it meets the sidewall, thereby
to route a volume of the fluid in the generally cylindrical pipe
into a region outside the baffles.
36. The system of claim 35, wherein each of the mounts includes
spherical roller bearings.
37. The system of claim 36, wherein the shaft includes an axially
linearly toothed exterior surface.
38. The system of claim 37 further comprising: opposing hub
assemblies configured to mount the plural blades, the hub
assemblies including axially linearly toothed interior surfaces
mate-able with the toothed exterior surface of the shaft; and
opposing shaft couplers for securely affixing the corresponding hub
assemblies to the shaft.
39. The system of claim 26 further comprising: a generally
cylindrical pipe configured with a diameter slightly greater than
the distance between the pair of hubs on the turbine shaft, the
generally cylindrical pipe mounting the turbine for rotation
therein in response to fluid flow through the generally cylindrical
pipe.
40. The system of claim 39, further comprising: an electric
generator or the like operatively coupled with a proximal end of
the shaft for rotation therewith to produce electric power in
response to fluid flow through the generally cylindrical pipe.
41. The system of claim 40, wherein the turbine is configured to
rotate in the same rotational direction, regardless of the
direction of generally axial fluid flow through the pipe.
42. The system of claim 41, wherein each of the mounts securing the
turbine shaft includes bearings.
43. The system of claim 42, further comprising: a generally
cylindrical tee section configured to mount to an outer sidewall of
the generally cylindrical pipe, the tee section housing an electric
generator that is operatively coupled for rotation with the shaft
of the turbine to produce electric power when the turbine is
rotating.
44. The system of claim 43 further comprising: a cylindrically
arched plate configured to cover an access hole in the generally
cylindrical pipe to substantially prevent fluid flow into the
generally cylindrical tee section.
45. The system of claim 46 further comprising: a circular flat or
concave plate that covers the access hole into the generally
cylindrical tee section.
46. The system of claim 45 further comprising: a generator that
sits on top of the circular flat or concave plate.
47. In a cylindrical turbine including a central shaft, opposing
hubs, spokes mounted on the opposing hubs and extending radially
therefrom, with the spokes mounting helically twisted blades on
their distal ends, the improvement comprising: configuring the
spokes and the twisted blades with substantially uniformly sized
and shaped airfoil cross sections thereon along the substantial
lengths of each.
48. The improvement of claim 47, wherein there is no configuring of
any of the spokes or twisted blades with transversely mounted
radial blades thereon.
Description
RELATED APPLICATIONS
[0001] This is a continuation-in-part of and claims the benefit of
priority from U.S. patent application Ser. No. 12/384,765 filed
Apr. 7, 2009, the contents of which are incorporated herein in
their entirety by this reference.
FIELD OF THE INVENTION
[0002] The invention relates generally to the field of
hydro-electric power generation. More particularly, the invention
relates to hydro-electric power generation via fluid flow past a
turbine.
BACKGROUND OF THE INVENTION
[0003] U.S. Pat. Nos. 5,451,137; 5,642,984; 6,036,443; 6,155,892;
6,253,700 B1; and 6,293,835 B2 to Gorlov disclose various
cylindrical turbines for power systems, the blades of the turbines
extending helically to sweep out an open cylinder. The patents
disclose mounting such turbines in rectangular and/or square
cross-sectional channels or ducts capable of conveying water that
rotates the turbines to generate hydro-electric power. Gorlov's
cylindrical turbine has helically curved/twisted blades or vanes
mounted to a central shaft by radial struts or spokes of seemingly
arbitrary or at least non-airfoil, e.g. circular, cross section.
PCT/US00/35471 describes and illustrates a cylindrical turbine
having helically twisted blades each with airfoil cross sections of
variable sizes along their extents. Each twisted blade is mounted
to a central rotating hub by a blade support member also having an
airfoil cross section. Two or more radial blades "uniformly
distributed" on some or all of the twisted blades make use of
deviated transverse flow in an axial direction parallel with the
turbine's shaft.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is an isometric exploded assembly drawing of a first
embodiment of the invention featuring an un-baffled cylindrical
turbine.
[0005] FIG. 2 is a front elevation of the assembled first
embodiment.
[0006] FIG. 3 is an isometric exploded assembly drawing of a second
embodiment of the invention featuring a baffled cylindrical
turbine.
[0007] FIG. 4 is a side elevation of the assembled second
embodiment.
[0008] FIG. 5 is an isometric exploded assembly drawing of the
cylindrical turbine of FIG. 1.
[0009] FIG. 6 is an isometric view of the assembled cylindrical
turbine.
[0010] Details A and B are fragmentary side elevations of the
turbine-containing pipe of FIG. 1 showing a side-by-side comparison
of two different embodiments of the circular plate shown therein.
Specifically, Detail A shows a flat circular plate and Detail B
shows a spherically concave circular plate for mounting a proximal
end of the turbine's shaft.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0011] FIG. 1 is an isometric exploded assembly drawing of a first
embodiment of the invented in-pipe hydro-electric power system 10
featuring an un-baffled cylindrical turbine. System 10 in
accordance with one embodiment of the invention includes a
T-section fluid (broadly encompassing a liquid such as water or a
gas such as air or the like material exhibiting useful flow
characteristics) pipe 12, a bulkhead or generator assembly 14, and
a cylindrical turbine assembly 16. Those of skill in the art will
appreciate, by brief reference to FIG. 2, that when assembled and
driven by fluid flow through pipe 12, turbine assembly 16 rotates
and system 10 produces hydro-electric power that can be stored,
consumed, or fed into a power grid.
[0012] Pipe 12 is generally cylindrical, having a generally
circular cross section, although within the spirit and scope of the
invention it can be slightly oval in cross section. Pipe 12
typically is a part of a longer and perhaps more complex fluid
conveyance or pipe system, and it will be appreciated that an
existing pipe system can readily be retrofitted with invented power
system 10 by sectioning and replacing the removed section with
power system 10. Thus, pipe 12 is equipped with circular flanges
12a and 12b for bolting on either end to upstream and downstream
pipe ends (not shown). Pipe 12 is provided with a small opening 12c
in a first region of the sidewall and a large opening 12d in a
diametrically opposed region thereof. As will be seen, small
opening 12c accommodates a shaft of the turbine therethrough, while
large opening 12d accommodates turbine assembly 16 therethrough.
Pipe 12 also is equipped with a flanged T-intersection pipe section
(a so-called "tee") that effectively mates with large opening 12d
at a right angle to the long axis of pipe 12.
[0013] Generator cap assembly 14 includes a circular arched plate
18 that effectively acts to close larger opening 12d when system 10
is assembled. Arched plate 18 provides a contiguous round wall
inside pipe 12 for the fluid to flow past, thereby avoiding
cavitation or other smooth fluid flow disruption within what would
otherwise act as a pocket volume within the tee section. A 3-vaned,
cylindrical spacer 20 holds arched plate 18 in place within the tee
section when a cover plate 22 including an annular seal 22a and a
circular plate 22b is bolted onto flange 12e. Circular plate 22b
has an opening 22ba therein with a mounting block 24 extending
therearound. A first mount 26 including a roller bearing assembly
mounts a proximal end of the shaft of turbine assembly 16 for
smooth rotation therethrough. A flat shim 22bb can be provided
between mounting block 24 and circular plate 22b.
[0014] A generator sub-assembly 28 bolts through a circular hole
arrangement within circular plate 22b. Generator sub-assembly 28
includes an annular spacer or standoff 30 for housing a generator
32 couple-able with the turbine's shaft, an annular rim 34 with a
first mechanical-lift tab 34a, and a cap 36 having a second
mechanical-lift tab 36a. Those of skill in the art will appreciate
that tabs 34a and 36a provide convenient tabs for lifting all or
part of the assembled tee-section electrical power generation
components during assembly, disassembly, or maintenance. Those of
skill will appreciate that the generator can be direct or
alternating current (DC or AC) and single-phase or 3-phase,
synchronized 120VAC or 240VAC, etc. and/or can be converted from
one to the other, depending upon the power requirements.
[0015] A mounting plate 12f is welded to pipe 12 around small
opening 12c and a second mount 38 including a roller-bearing
assembly that mounts a distal end of the shaft of turbine assembly
16 for smooth rotation therein. Those of skill in the art will
appreciate that, to accommodate the circular cross section of
cylindrical pipe 12, first mount 26 in accordance with one
embodiment of the invention includes a shim (not shown in pertinent
detail but believed to be understood from this brief description by
those of skill in the art) having an exterior planar surface and an
inner cylindrical surface for mating with the exterior cylindrical
surface of the pipe. The shim can be machined or formed by any
suitable process and of any suitable material that ensures
conformingly sealing engagement between the shaft and the pipe
opening through which the shaft extends. Either shim described
and/or illustrated herein will be understood to be optional, as
either can readily be incorporated into the corresponding mounting
block or plate.
[0016] Finally, generator assembly 14 includes mounting plate 12f
around small opening 12c of pipe 12 and a second mount 38 including
a roller-bearing assembly that mounts a distal end of the shaft of
turbine assembly 16 for smooth rotation therein. First and second
mounts 26 and 38 can take alternative forms, within the spirit and
scope of the invention, but it is believed that axial and radial
thrust handling is best achieved using spherical roller bearings
producing only rolling friction rather, for example, than sleeve
bearings or other sliding friction arrangements. The roller bearing
mounts described herein are believed to enable system 10 to operate
safely, reliably and durably to produce electricity with a fluid
flow rate through pipe 12 of as little as approximately 3-4
feet/second (fps).
[0017] Those of skill in the art will appreciate that turbine
assembly 16 is slipped through large opening 12d of pipe 12 and the
proximal end of its shaft is secured to second mount 38. Generator
assembly 14 is bolted onto flange 12e of pipe 12 and the
hydro-electric power system 10 is ready to operate. Power system 10
is fitted into or otherwise connected to a part of a pipe system
(not shown). When fluid flows through pipe 12, power system 10
generates electricity.
[0018] FIG. 2 is a side elevation of assembled system 10, and is
believed to be largely self-explanatory. Those of skill in the art
will appreciate that cylindrical turbine assembly 16 is generally
square in cross section, while the interior of pipe 12 is generally
circular in cross section. Thus, fluid within pipe 12 flows not
only through turbine assembly 16 to cause it to rotate and to
generate electricity via generator assembly 14, but also around
turbine assembly 16, with little electricity generation effect.
Nevertheless, efficient electricity generation is possible with the
un-baffled cylindrical turbine system shown in FIGS. 1 and 2, since
the cylindrical turbine assembly in accordance with the present
invention has a relatively small cross-sectional `solidity` (e.g.
flow-restricting and energy-producing ratio between closed and
total confronting surface area) effect on the flow of fluid
therethrough. Importantly, as will be seen by reference to FIGS. 5
and 6, cylindrical turbine assembly 16 is an extremely efficient
hydrofoil by virtue of an improved overall airfoil cross-sectional
design of the blades that extend rectilinearly from a central,
rotating shaft.
[0019] Those of skill in the art will appreciate now that helically
twisted and helically (or spirally) extending and cylindrically
arcing blades of turbine assembly 16 ensure that a portion of at
least one of the plural blades thereof is always optimally aligned
with the flow of the fluid through pipe 12. Indeed, in accordance
with the embodiments of the invention described and illustrated
herein, a portion of each of the plural blades thereof is always so
optimally aligned. Moreover, all such portions of each blade
present an extremely hydrodynamic airfoil cross section to the
flowing fluid, thereby virtually eliminating undesirable
cavitation. Surprisingly, it has been discovered that turbine
assemblies such as those described and illustrated herein rotate at
fluid flow rates as low as approximately 3-4 feet per second
(fps).
[0020] FIG. 3 is an isometric exploded assembly drawing of a second
embodiment of the invented in-pipe hydro-electric power system 10'
featuring a baffled cylindrical turbine. System 10' includes nearly
all the component parts of system 10 in the same configuration but
omits arched plate 18, includes a higher spacer 20', and includes a
baffle assembly 40 that extends around turbine assembly 16 within
pipe 12. Those of skill in the art will appreciate that interiorly
rectilinear and exteriorly curvilinear baffle assembly 40
effectively "squares the circle" within circular cross-sectional
pipe 12, thereby increasing and improving flow characteristics and
electrical generation efficiencies with the cylindrical turbine
embodiment of the invention.
[0021] Those of skill in the art will appreciate from FIG. 3 that
four baffles 42, 44, 46, and 48 are provided on one end of turbine
assembly 16, while four more baffles 50, 52, 54, and 56 are
provided on the other end thereof. The baffles are rectilinear in
their interior or proximal regions to mate with a rectilinear (e.g.
rectangular) open channel 58 (defined by four peripheral planar
sidewalls) that surrounds turbine assembly 16, while the baffles
are curvilinear, e.g. parabolic, in their exterior or distal
regions to mate with the interior of circularly cross-sectional
cylindrical pipe 12. Those of skill also will appreciate that the
baffles and rectangular channel can be made of any suitable
material, e.g. steel, and can be dimensioned and oriented for any
desired fluid flow adjustment at either end. In accordance with one
embodiment of the invention, each of baffles 42-56 is inclined
relative to the long central axis of pipe 12 at an angle .theta.
(refer briefly to FIG. 4) of approximately 10 degrees. Other
inclined angles are contemplated as being within the spirit and
scope of the invention. (For example, incline angles .theta. of
between approximately 5 degrees and 15 degrees can be used,
although it will be understood that a more gradual incline may
require a longer pipe 12 and a more abrupt incline may cause undue
turbulence.)
[0022] Thus, baffle assembly 40 can be described as a plurality of
structural inserts that effectively narrows the cross section of
the round pipe, each insert having a rectangular cross section
transverse to the pipe, the inserts collectively smoothly directing
essentially all of the fluid that would otherwise flow through the
round pipe instead through the rectangular, e.g. square,
cross-sectional turbine, i.e. within the turbine's perimeter.
[0023] Those of skill in the art also will appreciate from FIG. 3
(and also from FIG. 4) that each of the eight baffles that form a
part of baffle assembly 40 is equipped with a notch or vent 60 at
its distal extremity, the notch creating a small opening between
the baffles and their corresponding interior mating surfaces of
cylindrical pipe 12. These notches and the resulting openings
provide fluid flow through pipe 12 exterior to baffle assembly 40,
thus filling what would otherwise be a void and providing a
relatively static and stable fluid pressure outside the baffle
assembly but within the pipe. The notches thus avoid incidental
formation in that otherwise void region of pipe 12 of a no- or
low-fluid-pressure condition that might otherwise undesirably
stress or deform baffle assembly 40. Thus, the notches may be
referred to herein as pressure-equilibrium-promoting features.
[0024] Those of skill in the art will appreciate that baffle
assembly 40 may be thought of as having a so-called Venturi effect
on the fluid flow through the pipe and thus on the rotation of
turbine assembly 16. By reducing the cross section of the pipe, the
baffles effectively direct the fluid and increase its flow rate
through the cylindrical turbine. It has been determined that flow
rate increases significantly (and power thus even more
significantly) through baffle assembly 40 over those typical fluid
flow rates (e.g. approximately 15 fps) through configurations
having no baffle assembly.
[0025] FIG. 4 is a front elevation of assembled system 10'. FIG. 4
is thought to be mostly self-explanatory based upon the description
above regarding FIG. 3 to which it corresponds. The angle .theta.
of incline of the baffles can be more clearly seen, as can two of
the four notches such as notch 60 (which for the sake of clarity is
designated only once, although it will be understood that there are
eight such notches in accordance with one embodiment of the
invention). In accordance with this cylindrical-turbine embodiment
of the invention, sufficient clearance around the rotating
cylindrical turbine assembly and within the pipe is provided to
avoid undue compression of fluid at the turbine sweep boundaries,
as shown.
[0026] FIG. 5 is an isometric exploded assembly drawing of
cylindrical turbine assembly 16. Cylindrical turbine assembly 16
includes an axially (linearly) toothed collar 62 having an inner
diameter (ID) slightly greater than an outer diameter (OD) of a
shaft 64 around which it extends and to which it is fixedly mounted
via upper and lower split shaft couplers 66 and 68. The toothed
collar fixedly mounted via upper and lower couplers to the shaft
may be collectively referred to herein simply as shaft 70.
[0027] Evenly arcuately spaced around and extending radially from
shaft 70 are plural (e.g. three, in a so-called 180 degree
vertical-axis, helical turbine) upper spokes 72, 74, and 76, and
plural (e.g. three) lower spokes 78, 80, and 82. Those of skill in
the art will appreciate that the upper and lower spokes are
arcuately offset from one another by 60 degrees to mount
corresponding plural (e.g. three) helically twisted and arcuately
cylindrically extending turbine blades 84, 86, and 88.
Corresponding with each of plural spokes 72, 74, 76, 78, 80, and 82
is an inner hub 90, an outer hub 92, and a corner block 94 (which
are designated only once in FIG. 5 for the sake of clarity but
which will be understood to number the same as the number of blades
in the plurality). Those of skill in the art will appreciate that
each of the plural airfoil blades mounted on or otherwise connected
to or integral with a corresponding airfoil spoke is collectively
referred to herein as a blade assembly.
[0028] Those of skill in the art will appreciate that each of the
plural inner blocks has a correspondingly axially (linearly)
toothed inner arcuate surface for a secure grip on toothed collar
62. It will also be appreciated that each of the blades (including
the blade portion represented by the spokes) and the corresponding
corner blocks have an airfoil cross section, e.g NACA 20 or any
other suitable standard. Thus, the blades of cylindrical turbine
assembly 16 are of uniformly sized and shaped airfoil cross section
over their entire length and substantially all the way to the
central shaft that mounts their termini. This represents a striking
improvement over prior art helical turbines in which the disks,
spokes or struts that mount the helically twisted and arcuate
blades generally are not of airfoil cross section and are not of
uniform cross sectional size and shape and thus thus are thought by
some to cause undesirable cavitation and, more importantly, to
lower hydro-electric power generation efficiency. Suitable
fasteners such as hex bolts, lock washers, and set screws are used
to assemble the component parts of cylindrical turbine assembly 16,
as illustrated.
[0029] Those of skill in the art will appreciate that more or fewer
than three blades can be used in cylindrical turbine assembly 16 in
what is referred to herein as an arcuately spaced arrangement, i.e.
a uniformly spaced arrangement around the turbine's cross-sectional
circumference. For a three-blade cylindrical turbine, the blades
may be seen from FIGS. 5 and 6 to be spaced apart 120.degree., and
each blade extends along an arcuate angle .PHI. of 60.degree.
helically around the cylindrical shape (or so-called "sweep") of
the rotating turbine. This three-blade arrangement and airfoil
selection produces complete `overlap` of the blades in
cross-sectional view and a `solidity` (i.e. the ratio of closed to
open cross-sectional area within the pipe) of between approximately
15% and 20%. Those of skill will appreciate that the angle of blade
inclination follows from the selected ratio of turbine diameter to
height.
[0030] Other airfoil configurations and/or other numbers and
arrangements of the plurality of blades are contemplated as being
within the spirit and scope of the invention. For example, a
six-blade cylindrical turbine is contemplated, each blade having a
smaller width, to produce a similar solidity configuration and to
present smoother operation due to full overlap of the blades within
the cylinder (a so-called 360.degree. vertical-axis cylindrical
turbine design).
[0031] FIG. 6 is an isometric view of assembled cylindrical turbine
assembly 16. FIG. 6 is believed to be largely self-explanatory in
view of the detailed description above by reference to FIG. 5. FIG.
6 perhaps better illustrates the angles and arrangements and
helical curves and twists of the plurality of blades in cylindrical
turbine assembly 16. It will be appreciated that the angle of
inclination of the blades--i.e. the angle of intersection of a
plane in which lies each of the plurality of cylindrical turbine
blades (84, 86, and 88) and the central axis of the shaft in
accordance with one embodiment of the invention--is approximately
30 degrees, although other helical angles are contemplated as being
within the spirit and scope of the invention.
[0032] An alternative to the above circular plate 22b is
illustrated in Details A and B, which are fragmentary cut-away side
elevations featuring the interior of tee section 12e. Those of
skill in the art will appreciate that absolute and relative
dimensions in Details A and B are not to scale, as they are for
general structural comparison purposes.
[0033] A side-by-side comparison of Detail A, which features flat
circular plate 22b described above, and Detail B, which features a
spherically concave circular plate 22b', reveals some important
advantages of alternative plate 22b'. Flat circular plate 22b must
be formed of relatively thick material, thereby rendering it heavy
and difficult to handle. Spherically concave circular plate 22b' on
the other hand may be seen to be formed of relatively thin
material, thereby rendering it significantly lighter in weight and
significantly easier to handle.
[0034] This is by virtue of the curvature of alternative plate
22b'.
[0035] Moreover, the central region of flat circular plate 22b may
be seen to be farther from the turbine assembly, thus undesirably
extending the length of the turbine's shaft. Conversely, the
central region of spherically concave circular plate 22b' may be
seen to be closer to the turbine assembly, thereby desirably
shortening the required length or vertical span of the turbine's
shaft.
[0036] This too is by virtue of the curvature of alternative plate
22b'.
[0037] From Detail B, concave plate 22b' will be understood to be
of generally spherical shape with the concavity extending inwardly
from generator assembly (not shown for the sake of simplicity and
clarity in this view) and toward the turbine assembly 16' (shown
only schematically in these detailed views by way of dash-dot-dot
outlines, and the only difference from turbine assembly 16 being
the provision of a shorter shaft 64'). This inward or downwardly
oriented concave circular plate may be thought of and described
herein as an inverted dome (or inverted cupola). While a
spherically concave shape is illustrated and described, those of
skill in the art will appreciate that suitable modifications can be
made thereto without departing from the spirit and scope of the
invention. For example, an inverted dome featuring a parabolic
rather than a semi-circular cross section is possible, as are other
curvilinear cross sections of various aspect ratios (i.e. of
various depth-to-width ratios only one of which is shown with some
intentional depth exaggeration for the sake of clarity). Also, the
cupola-shaped plate in cross section can have a more rounded upper
shoulder, producing what might be thought of as complex curvature.
All such suitable alternative configurations are contemplated as
being within the spirit and scope of the invention.
[0038] Those of skill in the art will appreciate that mounting
details in such an alternative embodiment are modified
straightforwardly to accommodate inverted cupola-shaped circular
plate 22b' and its bolted assembly through annular seal 22a onto
standard flange 12e of pipe 12. For example, mounting block 24' may
include a shim 22bb' that is spherically convexly curved to mate
and seal the spherically concave curvature of the inside of the
inverted cupola. A rotor or other moving part of generator 32 will
be understood to mount to, for rotation with, the distal end of the
turbine's shaft directly above the opening in the central region of
spherical concave plate 22b'. Other components and techniques for
accommodating alternative spherically concave circular plate 22b'
are contemplated as being within the spirit and scope of the
invention.
[0039] The embodiment illustrated herein is a three-blade
cylindrical turbine assembly, but as few as two blades and as many
as twenty blades are contemplated as being within the spirit and
scope of the invention. More preferably, between approximately two
and eleven blades are contemplated. Most preferably, between
approximately three and seven blades are contemplated. Other
numbers and configurations of helically arced cylindrical turbine
blades are contemplated as being within the spirit and scope of the
invention. Those of skill in the art will appreciate best perhaps
from FIG. 5 that the blades of the cylindrical turbine assembly are
characterized along their entire length by airfoil cross sections.
This provides the turbine's hydrodynamics and efficiency at
generating hydro-electric power. In accordance with this
cylindrical-turbine embodiment of the invention, sufficient
clearance around the rotating cylindrical turbine assembly and
within the pipe is provided to avoid undue compression of fluid at
the turbine sweep boundaries (see FIGS. 2 and 4).
[0040] Those of skill will appreciate that the helical turbine
blades, within the spirit and scope of the invention, can be made
of any suitable material and by any suitable process. For example,
the blades can be made of aluminum, a suitable composite, or a
suitable reinforced plastic material. The blades can be made by
rotational or injection molding, extrusion, pultrusion, bending, or
other forming techniques consistent with the material used and
consistent with the cost-effective production of elongated bodies
having substantially constant cross sections. These and other
useful materials and processes are contemplated as being within the
spirit and scope of the invention.
[0041] The dynamic sweep (central diameter) of the rotating
cylindrical turbine assembly is greater than its static dimension
(central diameter) due to centrifugal forces impinging on the
turbine blades. This fact is accommodated by slightly under-sizing
the cylindrical turbine relative to the ID of the pipe, e.g. by
providing a small but preferably constant clearance of between
approximately 0.5 centimeters and 5 centimeters and preferably
between approximately 1 centimeter and 3 centimeters, depending
upon the diameter of pipe 12 and other application specifics. These
spacings are illustrative only, and are not intended to be
limiting, as alternative spacings are contemplated as being within
the spirit and scope of the invention.
[0042] Surprisingly, it has been discovered that baffles 42, 44,
46, and 48 near an upstream region of turbine assembly 16 can
increase the electrical energy production by between approximately
14% and 40% and more likely between approximately 20% and 30% over
the nominal output of the cylindrical turbine without such an
upstream baffle assembly 40 within the pipe.
[0043] Those of skill in the art will appreciate that the ratio
between the baffles' coverage and the turbine's sweep can be
between approximately 10% and 40% and more likely between
approximately 20% and 30%. Those of skill in the art will also
appreciate that the amount of baffle coverage may be application
specific, as it represents a tradeoff between volumetric flow rate
and head drop-off. Thus, alternative ranges of baffle coverage and
angle relative to turbine sweep are contemplated as being within
the spirit and scope of the invention.
[0044] Those of skill in the art will appreciate that the
cylindrical turbine can serve in power conversion systems other
than electric power generation. For example, axial kinetic energy
of a fluid can be converted to rotating kinetic energy for any
rotating machinery (e.g. a conveyor, a grinder, a drill, a saw, a
mill, a flywheel, etc.) including an electric generator or the like
(a like alternative, for example, includes an alternator, a
magneto, and any other suitable mechanical-to-electric power
conversion device). All such uses of the invented fluid turbine are
contemplated as being within the spirit and scope of the
invention.
[0045] Those of skill in the art will appreciate that orientation
of the invented system in its many embodiments is illustrative only
and should not be read as a limitation of the scope of the
invention. Thus, use of terms like upper and lower will be
understood to be relative not absolute, and are interchangeable. In
other words, the system can assume either vertical orientation,
within the spirit and scope of the invention, with the bulkhead
housing the generator and the turbine shaft extending relative to
the long axis of the pipe either up or down. Indeed, the system can
assume any other suitable angle in which the shaft of the turbine
extends approximately perpendicular to the direction of the fluid
flow.
[0046] Those of skill in the art will appreciate that component
parts of the invented systems can be made of any suitable material,
including steel, aluminum, and polymers or other composites. Most
parts can be steel, for example, as are the turbine shafts, flat
plates, and baffles. Remaining parts including spokes, hubs,
collars, coupling blocks, and blades can be made of machined,
extruded, or pultruded aluminum (the blades then being roll-formed
and/or twisted into the desired form) or of injection-molded,
reinforced plastic or any other suitable polymer or composite (e.g.
carbon or graphite). Any alternative material and any alternative
forming process is contemplated as being within the spirit and
scope of the invention.
[0047] Those of skill will also appreciate that the invented
systems are of easily scaled dimension up or down, depending upon
their application. So that while dimensions generally are not given
herein, dimensions will be understood to be proportionately
accurately illustrated, the absolute scale of which can be varied,
within the spirit and scope of the invention.
[0048] Those of skill in the art will appreciate that two or more
hydro-electric power generation systems can be installed at defined
intervals (in series) within and along a fluid conveying pipe,
thereby to multiply power generation. Those of skill in the art
also will appreciate that parallel arrangements of two or more
hydro-electric power generation systems can be installed within
branches of a fluid conveying pipe, thereby alternatively or
additionally to multiply power generation. Those of skill in the
art will appreciate that kick-start mechanisms can be added to the
hydro-electric power generation systems described and illustrated
herein, if needed, for use of such systems in tidal (bidirectional,
oscillating) flow applications. Those of skill will also appreciate
that fail-safe modes of operation can be achieved in the use of the
invented in-pipe hydro-electric power generation systems to prevent
self-destruction in the event of bearing failure or the like.
Finally, those of skill in the art will appreciate that such
hydro-electric power generation systems as are described and
illustrated herein can be placed within an exterior sleeve conduit
that protects the power generation system from the elements and/or
that facilitates power distribution along power cables or other
suitable conveyances to nearby storage devices or power grids.
[0049] It will be understood that the present invention is not
limited to the method or detail of construction, fabrication,
material, application or use described and illustrated herein.
Indeed, any suitable variation of fabrication, use, or application
is contemplated as an alternative embodiment, and thus is within
the spirit and scope, of the invention.
[0050] It is further intended that any other embodiments of the
present invention that result from any changes in application or
method of use or operation, configuration, method of manufacture,
shape, size, or material, which are not specified within the
detailed written description or illustrations contained herein yet
would be understood by one skilled in the art, are within the scope
of the present invention.
[0051] Accordingly, while the present invention has been shown and
described with reference to the foregoing embodiments of the
invented apparatus, it will be apparent to those skilled in the art
that other changes in form and detail may be made therein without
departing from the spirit and scope of the invention as defined in
the appended claims.
* * * * *