CA1202545A - Method and apparatus for generating hydroelectric power for low head waterways - Google Patents
Method and apparatus for generating hydroelectric power for low head waterwaysInfo
- Publication number
- CA1202545A CA1202545A CA000443548A CA443548A CA1202545A CA 1202545 A CA1202545 A CA 1202545A CA 000443548 A CA000443548 A CA 000443548A CA 443548 A CA443548 A CA 443548A CA 1202545 A CA1202545 A CA 1202545A
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- CA
- Canada
- Prior art keywords
- water
- wheel
- blades
- flow
- duct
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
- F03B—MACHINES OR ENGINES FOR LIQUIDS
- F03B7/00—Water wheels
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/20—Hydro energy
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Hydraulic Turbines (AREA)
Abstract
ABSTRACT
Conventional water wheels are rarely used to generate hydroelectric power due to the low efficiency caused by turbulence and splashing when water hits the blades, by excessive back pressure generated in housings which complete-ly enclose the water wheels, and by leakage of hydraulic pressure. This invention relates to a water wheel housed in a flow-duct which encloses only the blades of the water wheel, and which directs the flow of water onto the blades, thereby minimizing splashing and turbulence. The flow duct is designed to discharge the water at a point where the water ceases to exert a downward rotational torque on the wheel.
Novel seal means are provided around the periphery of the flow-duct so as to minimize leakage of hydraulic pressure.
Conventional water wheels are rarely used to generate hydroelectric power due to the low efficiency caused by turbulence and splashing when water hits the blades, by excessive back pressure generated in housings which complete-ly enclose the water wheels, and by leakage of hydraulic pressure. This invention relates to a water wheel housed in a flow-duct which encloses only the blades of the water wheel, and which directs the flow of water onto the blades, thereby minimizing splashing and turbulence. The flow duct is designed to discharge the water at a point where the water ceases to exert a downward rotational torque on the wheel.
Novel seal means are provided around the periphery of the flow-duct so as to minimize leakage of hydraulic pressure.
Description
~2(~Z54S
This invention relates to a method and apparatus for generating hydroelectric power from a waterway, such as a river.
It is common to use a turbine drivingly connected to an electric generator to generate hydroelectric power, where the turbine is positioned in the flow of the waterway, as at the oot of a dam or other drop in the waterway. The turbine is commonly positioned so that its axis of rotation is gen-erally parallel to the flow of water, and its blades are generally transverse to such flow, with a downstream inclin-ation thereto. With such an arrangement, the angle of inci-dence and resultant turbulence of the water impacting with the blades of the turbine impedes the efficiency of its oper-ation. This efficiency is further diminished because some water will flow between the turbine blades without striking them, with resultant loss of kinetic energy. Thus, the full force of the falling water is not being utilized to drive the turbine. Moreover, efficiency of these turbines is not great-er than 70-80%, with the result that they must be quite large to e~ficiently produce hydroelectric po~er~ The large size not only results in difficulty in transport and installation, but also in a high manufacturing cost.
Addikionally, such turbines are only effective when used in conjunction with large drops in the waterway, or, as ~S it is phrased in the art, with "high heads", having a minimum drop of 25 feet. The high head waterway requirement, coupled with the extremely large capital investment required, severe-ly limits the number of installations where such turbines can be economically used.
For these and other reasons, many electric power authorities have turned away from hydroelectric power genera-tion to other forms of electrical power generation, particularly nuclear power, which poses its own set of problems.
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-- 2 ~
Conventional water wheels have been used in the past to drive machinery, particularly with waterways having "low heads", iOe., drops less than 25 feet. They have not, how-ever, been used to any degree to generate hydroelectric power, as they suffer from many of the same problems as do turbines, having an even lower efficiency. More specifically, as the water is dropped from above onto the bLades of the water wheel, much splashing and turbulence is created, with the result that a large percentage of the water is ~ot re-tained on the blades of the wheel. Moreover, what water isretained on the blades is often dumped from the wheel in such a manner so as to impede the further rotation oE the wheel.
That is, the leading edges of the blades continue to be in contact with a portion of the water beyond the point where such portion ceases to ex~rt a downward rotational torque on the wheel, but xather, resists rotation thereof.
The present invention relates to the use of an improved water wheel for use in the generation of hydroelectric power, which water wheel overcomes the above limitations of the prior art.
The novel water wheel of the invention includesa flow-duct which encloses the blades of the water wheel on three sides, which directs the flow of water onto the blades of the water wheel, and which assists in maintaining the water on the blades so as to take advantage of the full weight of the water to drive the water wheel. Novel sealing ~lamps form a seal between the sides of the flow-duct and the sides of the wheel, further reducing turbulence and loss of water through leakage and splashing, so as to gain maximum rotational torque from the water flow.
The point of discharge of the water from the water wheel can be controlled by the length of the flow-d~ct, so that the water can be exhausted at a point where it ceases to exert a downward rotational torque on the wheel.
5~5 _ 3 _ The blades of the water whee] are curved upwardly to hold more water than a flat blade of similar dimensions.
Water wheels constructed according to ~he invention can be effectively used with low head waterways having a mod~rate flow and minimum drop of about 5 ~eet. Where the flow is mo-derate ~nd the drop is 15 feet, up to approximately 90% effi-ciency can be achieved, This invention therefore makes many small waterways available for hydroelectric generation on an efficient scale for the first -time, While the present inven-tion may also be used in place of -the aforementioned turbines for high head hydroelectric generation, where an efficiency similar to that of the turbine systems can be expected, the invention is, because of its simple design, installation and operation, likely to find its most frequent application in smaller more remote locations, such as Northern ~ntario, where small waten~ays adaptable to the invention are abundant and conventional supplies of electric power are not readily available.
There is thus provided, according to the present inven-tion, a method of generating hydroelectric power from a lowhead waterway comprising the steps of: channelling water from the waterway into a spillway; directing -the water from the spillway onto upwardly curved blades of a water wheel sur-rounded by a flow-duct so as to cause downward rotational motion of the wheel; discharging the water from the water wheel substantially at a point where the water ceases to ex-ert a downward rotational torque on the water wheel, and driving electrical generating means from said rotational movement of the water wheel.
There is also provided according to the present inven-tion an apparatus for generating hydroelectric power from a low head waterway comprising: a support structure; a water S~S
wheel having upwardly curved blades arranged around its cir-cumfer~nkial periphery, said water wheel being mounted ~or rota-tion on the support structure; a flow-duct having two side walls and a floor together defining a water retention portion of generally U-shaped cross-section surrounding said periphery so as to enclose the blades of such peripheral portion on three sides; sealing means adjustably fitted on the side walls so as to lessen leakage of water from between said periphery and said side walls; a spillway having a first higher upstream end adapted for fluid communication with the waterway and a second lower downstream end adapted to direct water from the spilLway onto the blades of the wa-~er wheel so as to cause xotational movement thereof; and~ electric generating means drivingly connected to the water wheel.
In order that the invention may be more fully and readily understood, one embodiment thereof will now be des-cribed by way of example, with reference to the accompanying drawings in which:
Figure l is a schematic side elevation, partly in phan-~o tom, of an apparatus according to the invention;
Figure 2 is a view similar to Figure l~ with the 5Up-port structure, generating means and drive gearing removed;
Figure 3 is a sectional view along line 3-3 of Figure
This invention relates to a method and apparatus for generating hydroelectric power from a waterway, such as a river.
It is common to use a turbine drivingly connected to an electric generator to generate hydroelectric power, where the turbine is positioned in the flow of the waterway, as at the oot of a dam or other drop in the waterway. The turbine is commonly positioned so that its axis of rotation is gen-erally parallel to the flow of water, and its blades are generally transverse to such flow, with a downstream inclin-ation thereto. With such an arrangement, the angle of inci-dence and resultant turbulence of the water impacting with the blades of the turbine impedes the efficiency of its oper-ation. This efficiency is further diminished because some water will flow between the turbine blades without striking them, with resultant loss of kinetic energy. Thus, the full force of the falling water is not being utilized to drive the turbine. Moreover, efficiency of these turbines is not great-er than 70-80%, with the result that they must be quite large to e~ficiently produce hydroelectric po~er~ The large size not only results in difficulty in transport and installation, but also in a high manufacturing cost.
Addikionally, such turbines are only effective when used in conjunction with large drops in the waterway, or, as ~S it is phrased in the art, with "high heads", having a minimum drop of 25 feet. The high head waterway requirement, coupled with the extremely large capital investment required, severe-ly limits the number of installations where such turbines can be economically used.
For these and other reasons, many electric power authorities have turned away from hydroelectric power genera-tion to other forms of electrical power generation, particularly nuclear power, which poses its own set of problems.
lZO;~
-- 2 ~
Conventional water wheels have been used in the past to drive machinery, particularly with waterways having "low heads", iOe., drops less than 25 feet. They have not, how-ever, been used to any degree to generate hydroelectric power, as they suffer from many of the same problems as do turbines, having an even lower efficiency. More specifically, as the water is dropped from above onto the bLades of the water wheel, much splashing and turbulence is created, with the result that a large percentage of the water is ~ot re-tained on the blades of the wheel. Moreover, what water isretained on the blades is often dumped from the wheel in such a manner so as to impede the further rotation oE the wheel.
That is, the leading edges of the blades continue to be in contact with a portion of the water beyond the point where such portion ceases to ex~rt a downward rotational torque on the wheel, but xather, resists rotation thereof.
The present invention relates to the use of an improved water wheel for use in the generation of hydroelectric power, which water wheel overcomes the above limitations of the prior art.
The novel water wheel of the invention includesa flow-duct which encloses the blades of the water wheel on three sides, which directs the flow of water onto the blades of the water wheel, and which assists in maintaining the water on the blades so as to take advantage of the full weight of the water to drive the water wheel. Novel sealing ~lamps form a seal between the sides of the flow-duct and the sides of the wheel, further reducing turbulence and loss of water through leakage and splashing, so as to gain maximum rotational torque from the water flow.
The point of discharge of the water from the water wheel can be controlled by the length of the flow-d~ct, so that the water can be exhausted at a point where it ceases to exert a downward rotational torque on the wheel.
5~5 _ 3 _ The blades of the water whee] are curved upwardly to hold more water than a flat blade of similar dimensions.
Water wheels constructed according to ~he invention can be effectively used with low head waterways having a mod~rate flow and minimum drop of about 5 ~eet. Where the flow is mo-derate ~nd the drop is 15 feet, up to approximately 90% effi-ciency can be achieved, This invention therefore makes many small waterways available for hydroelectric generation on an efficient scale for the first -time, While the present inven-tion may also be used in place of -the aforementioned turbines for high head hydroelectric generation, where an efficiency similar to that of the turbine systems can be expected, the invention is, because of its simple design, installation and operation, likely to find its most frequent application in smaller more remote locations, such as Northern ~ntario, where small waten~ays adaptable to the invention are abundant and conventional supplies of electric power are not readily available.
There is thus provided, according to the present inven-tion, a method of generating hydroelectric power from a lowhead waterway comprising the steps of: channelling water from the waterway into a spillway; directing -the water from the spillway onto upwardly curved blades of a water wheel sur-rounded by a flow-duct so as to cause downward rotational motion of the wheel; discharging the water from the water wheel substantially at a point where the water ceases to ex-ert a downward rotational torque on the water wheel, and driving electrical generating means from said rotational movement of the water wheel.
There is also provided according to the present inven-tion an apparatus for generating hydroelectric power from a low head waterway comprising: a support structure; a water S~S
wheel having upwardly curved blades arranged around its cir-cumfer~nkial periphery, said water wheel being mounted ~or rota-tion on the support structure; a flow-duct having two side walls and a floor together defining a water retention portion of generally U-shaped cross-section surrounding said periphery so as to enclose the blades of such peripheral portion on three sides; sealing means adjustably fitted on the side walls so as to lessen leakage of water from between said periphery and said side walls; a spillway having a first higher upstream end adapted for fluid communication with the waterway and a second lower downstream end adapted to direct water from the spilLway onto the blades of the wa-~er wheel so as to cause xotational movement thereof; and~ electric generating means drivingly connected to the water wheel.
In order that the invention may be more fully and readily understood, one embodiment thereof will now be des-cribed by way of example, with reference to the accompanying drawings in which:
Figure l is a schematic side elevation, partly in phan-~o tom, of an apparatus according to the invention;
Figure 2 is a view similar to Figure l~ with the 5Up-port structure, generating means and drive gearing removed;
Figure 3 is a sectional view along line 3-3 of Figure
2; and Figure ~ is a perspective view showing in detail a por-tion of Figure 2~
The device illustrated comprises a water wheel~ gener-ally designated lO~ which is mounted for rotation about an axle 11 on a support structure, generally designated 12. Such mounting is by conventional means, such as by journalling in a bearing housing 13, which housing can be adjustably positioned \ .
25~
on the support structure 12 by means of adjustment screws 14.
The water wheel 10 is composed of two annular side panels 15 and a circumferential peripheral panel 16. The side and circumferential panels 15,16 are formed of metal, or other suitable material, and are joined at their common edges by, for example, welding. It is also possible to con-struct the wheel 10 with a unitary construction, as where side and peripheral panels 15,16 are moulded as a single unit from a lightweight, durable and water resistant material, such as fibreglass. Axle 11 is mounted in any conventional fashion at the centre of wheel 10. In the arrangement shown, axle 11 extends through the centre of side panels 15, and is rigidly affixed to both panels, as by welding, with its free ends journalled in housing 13. Other conventional mounting ar-rangements are possible, so long as they allow for relativelyfree rotation of wheel 10 true to centre.
The wheel 10 has arranged around its entire circumfer-ential periphery, that is upon the outer surface of panel 16, a plurality of evenly spaced blades 17 of upwardly curved cross-section. As shown, the blades 17 have a generally con-cave cross-section with an outer edge 22. It is preferable, for ease of fabri~ation, maintenance and replacement, that blades 17 be made of a durable, lightweight, corrosion re-sistant material, such as for example, aluminum or stainless steel, and that they have a unit construc~ion. One form of unit blade construction is readily apparent from Figures 3 and 4, where it will be seen that each blade 17 has an upper flange 18 and a lower flange 19, drilled to accommodate fast-ening means such as bolts 20. The upper flange 18 of a blade 30 17 overlaps the lower flange 19 o the blade 17 next above on the wheel 10, with bolts 20 passing through the aligned holes 21 of the overlapping flanges 18,19, so as to fasten the flanges 17 to the circumferential panel 16. All of the blades 17 extend axially to, but not beyond, the opposite side panels .
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15 of wheel 10, and all curve in the same direction, that being upwar~ly at the poxtion of the wheel 10 shown at the right of Figure 2, which portion is in first contact with the incoming water flow (shown as a solid arrow at the upper right of Figure 1). The blades 17 must each he of sufficient thickness to support a volume of water equal to the volume defined by the space between two adjacent blades, between imaginary radial outward projections of both side panels 10 and between the outer edge 22 of each blade 17.
A flow-duct~ generally designated 23, having two side walls 24 and a floor 25, together defining a water retention portion, generally designated 47, of generally U-shaped cross-section, surrounds a peripheral portion of the water wheel 10, beginning at the point of entry of the water onto the water wheel (shown to the upper right o~ Figure 1) and ending at the point of discharge of the water from the wheel 10 (shown to the lower left of Figure 1) so as to enclose the blades 17 within the peripheral portion of the wheel 10 on three sides of said blades. The flow-duct 23 is attached to the support structure 12 by conventional supportin~ means (not shown).
The flow-duct 23 is fabricated from metal or other suitable material and the two side walls 24 are preferably separated throughout the water retention portion 47 by a distance just sufficient to allow the circumferential periphery of the wheel 10 to rotate freely therebetween. The flow-duct 23 is con-structed and positioned such that the clearance between thefloor 25 and the outer edges 22 of ~lades 17 is only that necessary for the wheel 10 to freely rotate. The side walls 24 extend radially inwardly toward axle 11 such that they peripherally cover at least the outer third of the radius of wheel 10.
A spillway 26 of cement or metal, or other suitable materials, is disposed at the upper end of the flow~duct 23.
The spillway 26 may open at the top, or, as shown, may be ` 35 enclosed on all sides. The spillway has a first higher upstream en~ 27 adapted for fluid communication with the waterway (not shown) and a second lower downstrea~ end 28 adapted to direct water from the spillway 26 onto the blades 17 of the water wheel 10 so as to cause rotational movement thereof. The upstream end 27 is maintained at a higher level than the downstream end 28 to racilitate water flow there-between by means o~ conventional supporting means, such as brackets 33 embedded in cement columns 29, which are in turn anchored in ground 30. Similar cement columns 31 may be used 1~ to provide a firm base for mounting support beams 32, to which beams support structure 12 is anchored in a conventional manner.
The second end 28 is adapted to direct water from spillway 26 onto blades 17 by overlying an intake plenum 15 portion 33 of flow-duct 23, which plenum portion 33 prefer ably is fitted with guide vanes 34 which ser~e to minimize turbulence in the transfer of the water from spillway 26 to blades 17 and to structurally reinforce intake plenum por-tion 33.
As has been previously outlined, the weight of water flowing from the spillway 26 onto blades 17 causes wheel 10 to be unbalanced, generating a ro~ational torque on the wheel 10 which causes rotational movement of the wheel 10, being clockwise rotational movement as seen in Figures 1 and 2.
A main spur gear 35 is rigidly affixed to side panel 15 in concentric arrangement with axle 11 so as to rotate with wheel 10. Subsidiary gearing 36, acting through drive belt 37, drivinyly connects water wheel 10 to electric gen-erating means 38 mounted on support beams 32. The electric generating means is of readily available conventional design.
In the preferred embodiment illustrated~ the retention portion, defined by side walls 24 and floor 25, terminates 5~5 substantially at a point where the water dumped from the blades 17 ceases to exert a rotational torque on wheel 10.
Such point is at the nadir of rotation, where the component of force from the weight of the water is directionally straight down ~i.e. parallel to the vertical). A discharge portion 38 of the flow-duct 23 preferably begins at the point where the water retention portion 47 terminates. The floor 25 of the flow-duct 23 slopes sharply downwardly at the discharge por-tion 38 so as to facilitate quick discharge of the water from the retention portion 47 at -the aforementioned point.
Sealing means adapted to lessen leakage of water from between the water wheel L0 and the re~ention portion 47 of the flow-duct 23, thus increasing the efficieny of the flow-duct, are fitted on the side walls 24 of the flow-duct 23.
~s shown in Figure 3, the sealing means preferably comprises sealing clamps, generally designated 39, constructed of, for example, light-gage stainless steel, and are disposed, one each, along the upper free edges 40 of the side walls 24 in the water retention portion 47 of the flow-duct 23. The clamps 39 have a generally U-shaped portion 41 adapted to overlie and releasably grip said free edges 40 of the side walls ~4 and a flange portion 42 extending downwardly and axially inwardly toward the side panels 15 of water wheel 10.
The releasable gripping of the free edges 40 is accomplished by means oE bolts 43 extending through outer wall 44 of clamp portion 41, in screw-threaded engagement therewith, and through side walls 24 of flow-duct 23 in screw-threaded engagement therewith to contact inner wall 45 of clamp portion 41, such that by adjusting the length of the secti~n of bolts 43 be-30 tween the side walls 24 of flow-duct 23 and the inner wall 45 of clamp portion 41 of sealing clamp 39, the clearance between the flange portion 42 of sealing clamp 39 and the side panels 15 of wheel lO can be variably adjusted. Preferably, the flange portion 42 should be capable of adjustment to within 35 l/8"-3/16" clearance of the side panels 15. The use of light , . , ~2~Z~5 g ~age stainless steel or other flexible materials in the con-struction of the sealing clamps 39 allows a degree of flexion of the flange portion 42, if contacted by the side panels 15 during rotation of wheel 10.
.
To generate hydroelectric power using the apparatus herein described, the following steps are followed. After assembling the apparatus at a suitable site near a natural or artificial drop in a waterway, water from the waterway is channelled by any conventional means into a spillway 26. The water flows along the spillway 26 onto upwardly curved blades 17 of the water wheel 10/ surrounded by flow-duct 23 as here-inbefore described, thereby causing downward rotational move-ment (i.e~ clockwise as seen in Figures 1 and 2~ of the water wheel 10. The water is then exhausted from the water wheel substantially at a point where it ceases to exert a downward rotational torque on the water wheel (i.e. substantially at the nadir o~ rotation). The rotational movement of the water wheel 10 is used to drive electrical generating means 46 of conventional design, either directly or through interconnec-ting gear means.
While but one specific example of the present inven-tion is herein shown and describedl it will be understood that various changes in size, shape and arrangement of parts may be made without departing from the spirit of the inven-tion. For example, the spillway 26 used need not be as shown,but could, at least in part, be simply a passage through a cement barrier wall, as for e~ample, a dam, where the dam is used to enlarge or otherwise alter the waterway. Also, it is desirable to have the electrical generating means 46 structurally isolated from the water wheel on its own base separatel~ anchored in the ground 30, and driven from the wheel 10 by interconnecting drive means, such as a drive belt, capable of transmitting said drive without transmitting vibrations from the wheel 10 to the generating means 46 9 or vice versa.
The device illustrated comprises a water wheel~ gener-ally designated lO~ which is mounted for rotation about an axle 11 on a support structure, generally designated 12. Such mounting is by conventional means, such as by journalling in a bearing housing 13, which housing can be adjustably positioned \ .
25~
on the support structure 12 by means of adjustment screws 14.
The water wheel 10 is composed of two annular side panels 15 and a circumferential peripheral panel 16. The side and circumferential panels 15,16 are formed of metal, or other suitable material, and are joined at their common edges by, for example, welding. It is also possible to con-struct the wheel 10 with a unitary construction, as where side and peripheral panels 15,16 are moulded as a single unit from a lightweight, durable and water resistant material, such as fibreglass. Axle 11 is mounted in any conventional fashion at the centre of wheel 10. In the arrangement shown, axle 11 extends through the centre of side panels 15, and is rigidly affixed to both panels, as by welding, with its free ends journalled in housing 13. Other conventional mounting ar-rangements are possible, so long as they allow for relativelyfree rotation of wheel 10 true to centre.
The wheel 10 has arranged around its entire circumfer-ential periphery, that is upon the outer surface of panel 16, a plurality of evenly spaced blades 17 of upwardly curved cross-section. As shown, the blades 17 have a generally con-cave cross-section with an outer edge 22. It is preferable, for ease of fabri~ation, maintenance and replacement, that blades 17 be made of a durable, lightweight, corrosion re-sistant material, such as for example, aluminum or stainless steel, and that they have a unit construc~ion. One form of unit blade construction is readily apparent from Figures 3 and 4, where it will be seen that each blade 17 has an upper flange 18 and a lower flange 19, drilled to accommodate fast-ening means such as bolts 20. The upper flange 18 of a blade 30 17 overlaps the lower flange 19 o the blade 17 next above on the wheel 10, with bolts 20 passing through the aligned holes 21 of the overlapping flanges 18,19, so as to fasten the flanges 17 to the circumferential panel 16. All of the blades 17 extend axially to, but not beyond, the opposite side panels .
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15 of wheel 10, and all curve in the same direction, that being upwar~ly at the poxtion of the wheel 10 shown at the right of Figure 2, which portion is in first contact with the incoming water flow (shown as a solid arrow at the upper right of Figure 1). The blades 17 must each he of sufficient thickness to support a volume of water equal to the volume defined by the space between two adjacent blades, between imaginary radial outward projections of both side panels 10 and between the outer edge 22 of each blade 17.
A flow-duct~ generally designated 23, having two side walls 24 and a floor 25, together defining a water retention portion, generally designated 47, of generally U-shaped cross-section, surrounds a peripheral portion of the water wheel 10, beginning at the point of entry of the water onto the water wheel (shown to the upper right o~ Figure 1) and ending at the point of discharge of the water from the wheel 10 (shown to the lower left of Figure 1) so as to enclose the blades 17 within the peripheral portion of the wheel 10 on three sides of said blades. The flow-duct 23 is attached to the support structure 12 by conventional supportin~ means (not shown).
The flow-duct 23 is fabricated from metal or other suitable material and the two side walls 24 are preferably separated throughout the water retention portion 47 by a distance just sufficient to allow the circumferential periphery of the wheel 10 to rotate freely therebetween. The flow-duct 23 is con-structed and positioned such that the clearance between thefloor 25 and the outer edges 22 of ~lades 17 is only that necessary for the wheel 10 to freely rotate. The side walls 24 extend radially inwardly toward axle 11 such that they peripherally cover at least the outer third of the radius of wheel 10.
A spillway 26 of cement or metal, or other suitable materials, is disposed at the upper end of the flow~duct 23.
The spillway 26 may open at the top, or, as shown, may be ` 35 enclosed on all sides. The spillway has a first higher upstream en~ 27 adapted for fluid communication with the waterway (not shown) and a second lower downstrea~ end 28 adapted to direct water from the spillway 26 onto the blades 17 of the water wheel 10 so as to cause rotational movement thereof. The upstream end 27 is maintained at a higher level than the downstream end 28 to racilitate water flow there-between by means o~ conventional supporting means, such as brackets 33 embedded in cement columns 29, which are in turn anchored in ground 30. Similar cement columns 31 may be used 1~ to provide a firm base for mounting support beams 32, to which beams support structure 12 is anchored in a conventional manner.
The second end 28 is adapted to direct water from spillway 26 onto blades 17 by overlying an intake plenum 15 portion 33 of flow-duct 23, which plenum portion 33 prefer ably is fitted with guide vanes 34 which ser~e to minimize turbulence in the transfer of the water from spillway 26 to blades 17 and to structurally reinforce intake plenum por-tion 33.
As has been previously outlined, the weight of water flowing from the spillway 26 onto blades 17 causes wheel 10 to be unbalanced, generating a ro~ational torque on the wheel 10 which causes rotational movement of the wheel 10, being clockwise rotational movement as seen in Figures 1 and 2.
A main spur gear 35 is rigidly affixed to side panel 15 in concentric arrangement with axle 11 so as to rotate with wheel 10. Subsidiary gearing 36, acting through drive belt 37, drivinyly connects water wheel 10 to electric gen-erating means 38 mounted on support beams 32. The electric generating means is of readily available conventional design.
In the preferred embodiment illustrated~ the retention portion, defined by side walls 24 and floor 25, terminates 5~5 substantially at a point where the water dumped from the blades 17 ceases to exert a rotational torque on wheel 10.
Such point is at the nadir of rotation, where the component of force from the weight of the water is directionally straight down ~i.e. parallel to the vertical). A discharge portion 38 of the flow-duct 23 preferably begins at the point where the water retention portion 47 terminates. The floor 25 of the flow-duct 23 slopes sharply downwardly at the discharge por-tion 38 so as to facilitate quick discharge of the water from the retention portion 47 at -the aforementioned point.
Sealing means adapted to lessen leakage of water from between the water wheel L0 and the re~ention portion 47 of the flow-duct 23, thus increasing the efficieny of the flow-duct, are fitted on the side walls 24 of the flow-duct 23.
~s shown in Figure 3, the sealing means preferably comprises sealing clamps, generally designated 39, constructed of, for example, light-gage stainless steel, and are disposed, one each, along the upper free edges 40 of the side walls 24 in the water retention portion 47 of the flow-duct 23. The clamps 39 have a generally U-shaped portion 41 adapted to overlie and releasably grip said free edges 40 of the side walls ~4 and a flange portion 42 extending downwardly and axially inwardly toward the side panels 15 of water wheel 10.
The releasable gripping of the free edges 40 is accomplished by means oE bolts 43 extending through outer wall 44 of clamp portion 41, in screw-threaded engagement therewith, and through side walls 24 of flow-duct 23 in screw-threaded engagement therewith to contact inner wall 45 of clamp portion 41, such that by adjusting the length of the secti~n of bolts 43 be-30 tween the side walls 24 of flow-duct 23 and the inner wall 45 of clamp portion 41 of sealing clamp 39, the clearance between the flange portion 42 of sealing clamp 39 and the side panels 15 of wheel lO can be variably adjusted. Preferably, the flange portion 42 should be capable of adjustment to within 35 l/8"-3/16" clearance of the side panels 15. The use of light , . , ~2~Z~5 g ~age stainless steel or other flexible materials in the con-struction of the sealing clamps 39 allows a degree of flexion of the flange portion 42, if contacted by the side panels 15 during rotation of wheel 10.
.
To generate hydroelectric power using the apparatus herein described, the following steps are followed. After assembling the apparatus at a suitable site near a natural or artificial drop in a waterway, water from the waterway is channelled by any conventional means into a spillway 26. The water flows along the spillway 26 onto upwardly curved blades 17 of the water wheel 10/ surrounded by flow-duct 23 as here-inbefore described, thereby causing downward rotational move-ment (i.e~ clockwise as seen in Figures 1 and 2~ of the water wheel 10. The water is then exhausted from the water wheel substantially at a point where it ceases to exert a downward rotational torque on the water wheel (i.e. substantially at the nadir o~ rotation). The rotational movement of the water wheel 10 is used to drive electrical generating means 46 of conventional design, either directly or through interconnec-ting gear means.
While but one specific example of the present inven-tion is herein shown and describedl it will be understood that various changes in size, shape and arrangement of parts may be made without departing from the spirit of the inven-tion. For example, the spillway 26 used need not be as shown,but could, at least in part, be simply a passage through a cement barrier wall, as for e~ample, a dam, where the dam is used to enlarge or otherwise alter the waterway. Also, it is desirable to have the electrical generating means 46 structurally isolated from the water wheel on its own base separatel~ anchored in the ground 30, and driven from the wheel 10 by interconnecting drive means, such as a drive belt, capable of transmitting said drive without transmitting vibrations from the wheel 10 to the generating means 46 9 or vice versa.
Claims (5)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An apparatus for generating hydroelectric power from a low head waterway comprising:
a support structure;
a water wheel having rigid upwardly curved blades arranged around its periphery, said water wheel being mounted for rotation on the support structure;
a flow-duct having two side walls and a floor to-gether defining a water retention portion of generally U-shaped cross-section surrounding only said periphery so as to enclose the blades on three sides, said water retention portion terminating substantially at a point where water from the blades ceases to exert a rotational torque on the water wheel;
sealing means adjustably fitted on the side walls so as to lessen leakage of water from between said periphery and said side walls;
a spillway having a first higher upstream end adapted for fluid communication with the waterway and a second lower downstream end adapted to direct water from the spillway onto the blades of the water wheel at a position above the axis thereof, so as to cause rotational movement thereof; and electric generating means drivingly connected to the water wheel.
a support structure;
a water wheel having rigid upwardly curved blades arranged around its periphery, said water wheel being mounted for rotation on the support structure;
a flow-duct having two side walls and a floor to-gether defining a water retention portion of generally U-shaped cross-section surrounding only said periphery so as to enclose the blades on three sides, said water retention portion terminating substantially at a point where water from the blades ceases to exert a rotational torque on the water wheel;
sealing means adjustably fitted on the side walls so as to lessen leakage of water from between said periphery and said side walls;
a spillway having a first higher upstream end adapted for fluid communication with the waterway and a second lower downstream end adapted to direct water from the spillway onto the blades of the water wheel at a position above the axis thereof, so as to cause rotational movement thereof; and electric generating means drivingly connected to the water wheel.
2. An apparatus according to claim 1 wherein the flow-duct has a discharge portion which commences substantially at said point.
3. An apparatus according to claim 2 wherein said sealing means comprises sealing clamps having a generally U-shaped portion adapted to overlie and releasably grip the free edges of said side walls and a flange portion extending axially inwardly toward the periphery of the water wheel.
4. An apparatus according to claim 3 wherein the sealing clamps are constructed of light gauge medium tempered stainless steel.
5. An apparatus according to claim 4 wherein the flange portion extends toward the water wheel to within 1/8"-3/16" clearance therewith.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000443548A CA1202545A (en) | 1983-12-16 | 1983-12-16 | Method and apparatus for generating hydroelectric power for low head waterways |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000443548A CA1202545A (en) | 1983-12-16 | 1983-12-16 | Method and apparatus for generating hydroelectric power for low head waterways |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1202545A true CA1202545A (en) | 1986-04-01 |
Family
ID=4126765
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000443548A Expired CA1202545A (en) | 1983-12-16 | 1983-12-16 | Method and apparatus for generating hydroelectric power for low head waterways |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1202545A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5755553A (en) * | 1993-10-21 | 1998-05-26 | Laemthongsawad; Prasert | Water turbine |
| GB2436704A (en) * | 2006-03-31 | 2007-10-03 | Hydreau Ltd | Waterwheel |
| CN102828888A (en) * | 2012-07-23 | 2012-12-19 | 沈永林 | External hydraulic ultra-generating system of reservoir |
| JP2014109235A (en) * | 2012-12-03 | 2014-06-12 | Eiichi Kikuchi | Water turbine device |
| GB2551519A (en) * | 2016-06-20 | 2017-12-27 | Jane Carruthers Penelope | Waterwheel |
| CN113606077A (en) * | 2020-05-04 | 2021-11-05 | 杨传成 | Torque-variable stamping water energy generator |
-
1983
- 1983-12-16 CA CA000443548A patent/CA1202545A/en not_active Expired
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5755553A (en) * | 1993-10-21 | 1998-05-26 | Laemthongsawad; Prasert | Water turbine |
| GB2436704A (en) * | 2006-03-31 | 2007-10-03 | Hydreau Ltd | Waterwheel |
| CN102828888A (en) * | 2012-07-23 | 2012-12-19 | 沈永林 | External hydraulic ultra-generating system of reservoir |
| JP2014109235A (en) * | 2012-12-03 | 2014-06-12 | Eiichi Kikuchi | Water turbine device |
| GB2551519A (en) * | 2016-06-20 | 2017-12-27 | Jane Carruthers Penelope | Waterwheel |
| WO2017220995A1 (en) * | 2016-06-20 | 2017-12-28 | Carruthers Penelope Jane | Waterwheel |
| US10954913B2 (en) | 2016-06-20 | 2021-03-23 | Penelope Jane Carruthers | Waterwheel |
| GB2551519B (en) * | 2016-06-20 | 2021-04-14 | Jane Carruthers Penelope | Waterwheel |
| CN113606077A (en) * | 2020-05-04 | 2021-11-05 | 杨传成 | Torque-variable stamping water energy generator |
| CN113606077B (en) * | 2020-05-04 | 2023-08-15 | 杨传成 | Moment-changing stamping hydraulic power generator |
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