GEAR PUMP FOR HYDROELECTRIC POWER GENERATION
TECHNICAL FIELD
[001] The present disclosure relates generally to a gear pump unit for generating
hydroelectric power. More specifically, the bidirectional gear pump unit utilizes a modified
supercharger to generate electricity.
BACKGROUND
[002] By applying the simple concept of using water to turn a turbine that in turn
turns a metal shaft in an electric generator, a hydroelectric power generator harnesses energy
to generate electricity. The turbine is an important component of the hydroelectric power
generator. A turbine is a device that uses flowing fluids to produce electrical energy. One
of the parts is a runner, which is the rotating part of the turbine that converts the energy of
falling water into mechanical energy.
[003] There are two main types of hydro turbines, impulse and reaction. Impulse
turbines use the velocity of the water to move the runner and discharges the water at
atmospheric pressure. There is no suction on the down side of the turbine, and the water
flows out the bottom of the turbine housing after hitting the runner. An impulse turbine is
generally suitable for high head applications.
[004] Reaction turbines develop power from the combined action of pressure and
moving water. The runner is placed directly in a water stream flowing over the blades.
Reaction turbines are generally used for sites with lower head than compared with the
impulse turbines. Reaction turbines must be encased to contain the water pressure, or they
must be fully submerged in the water flow.
[005] Current hydroelectric power generators use centrifugal devices like propellers
and impellers in low (<30m) and medium (30-300m) head applications. Head is pressure
created by the difference in elevation between the water intake for the turbine and the water
turbine. Many propeller and impeller type turbines require high pressure head to perform
efficiently, but many geographic locations do not have enough elevation change to create
high pressure head.
[006] To create head, water can be collected or diverted. So, some systems employ
a pump to move water so that it can pass through the turbine. This increases the complexity
by having one set of pipes and diversion mechanisms aimed at the turbine, and a second set
of such equipment for the pump.
SUMMARY
[007] The present disclosure proposes an improved gear pump and turbine unit that
is capable of moving a large volume of water in a bidirectional manner. The unit can
operate efficiently in high and low head applications by leveraging attributes of both impulse
and reaction turbines. And, the device is operable fully or partially submerged and can use a
siphon effect to operate when not submerged at all. The device can be installed in any
orientation, alleviating issues of precise alignment for power generation.
[008] In one embodiment, a gear pump unit for hydroelectric power generation may
comprise a gear pump (131). The gear pump (131) comprises a case (131B) comprising a
fluid inlet (132) and an outlet (135). A first rotor (133) is in the case (13 IB), the first rotor
comprising a first plurality of radially spaced teeth (133A, 133B, 133C), wherein the first
plurality of radially spaced teeth wrap around the first rotor helically in a clockwise direction.
A second rotor (134) is in the case (13 IB), the second rotor comprising a second plurality of
radially spaced teeth (134A, 134B, 134C), wherein the second plurality of radially spaced
teeth wrap around the second rotor helically in a counter-clockwise direction, and wherein
the first plurality of teeth mesh with the second plurality of teeth. A shaft (136) operatively
connects to the first rotor (133) and to the second rotor (134). A generator (138) operatively
connects to the shaft (136). A control module 150 operatively connects to the gear pump
(131) and is configured to selectively rotate the first rotor in a first direction and to
selectively rotate the second rotor in a second direction. The control mechanism is further
configured to selectively reverse the rotation direction of the first rotor and to selectively
reverse the rotation direction of the second rotor.
[009] A method of operating a hydroelectric power gear pump unit (130) comprises
the step of supplying a fluid to an inlet (132) of a gear pump (131) case (13 IB). Fluid moves
through through a chamber (13 1A) of the case (13 IB) by rotating a first rotor (133) in the
case (13 IB), the first rotor comprising a first plurality of radially spaced teeth (133A, 133B,
133C). Fluid moves through the chamber (131A) of the case (13 IB) by simultaneously
rotating a second rotor (134) in the case (13 IB), the second rotor comprising a second
plurality of radially spaced teeth (134A, 134B, 134C). Fluid is expelled through an outlet
energy of the first rotor and the rotational energy of the second rotor to a generator (138).
Pumping is performed by reversing the rotating of the first rotor and the second rotor to
move the fluid from the outlet (135) to the inlet (132).
[010] It is to be understood that both the foregoing general description and the
following detailed description are exemplary and explanatory only and are not restrictive of
the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[01 1] The accompanying drawings, which are incorporated in and constitute a part
of this specification, illustrate principles of the disclosure.
[012] FIG. 1A is a schematic of a high head hydroelectric power generation system.
[013] FIG. IB is an alternative schematic of a high head hydroelectric power
generation system.
[014] FIG. 2 is a schematic view of a gear pump unit.
[015] FIG. 3 is a schematic of a TVS type supercharger gear pump unit.
[016] FIG. 4 is a schematic of a low head application
DETAILED DESCRIPTION
[017] Reference will now be made in detail to the present exemplary embodiments,
examples of which are illustrated in the accompanying drawings. Wherever possible, the
same reference numbers will be used throughout the drawings to refer to the same or like
parts. In this specification, upstream and downstream are relative terms that explain a
relationship between parts in a fluid flow environment. Water, when flowing according to
natural forces, moves from a first upstream location to a second downstream location. When
mechanical means intervene, the flow direction can be altered, so the terms upstream and
downstream assist with explaining the natural starting point (upstream) with respect to a
location water would naturally move to (downstream).
[018] FIG. 1A shows a schematic view of hydroelectric power generation system
10. In this example, system 10 is a high head system with a dam 100 forming a reservoir
110 of water. System 10 comprises a penstock 120 and a gear pump unit 130. The penstock
120 may be a tube like structure that extends from upstream of the gear pump unit 130 to the
gear pump unit 130. The penstock 120 is a conduit for water. The penstock 120 may be
divided into three main parts. A first leg 120A of the penstock 120 is placed in reservoir
110. Reservoir 110 is located in an upstream portion of a river 160. Top, or second, part
120B of the penstock 120 is located on the top of a dam 100. The third leg 120C of the
penstock 120 is located on a downstream side of reservoir 110. The leg 120C is extended to
an inlet port 132 of the gear pump unit 130 to supply water. The gear pump unit 130 is
connected to the penstock 120 to pump water upstream to return water to the reservoir 110.
Further, the gear pump unit 130 may operate in a turbine mode to generate hydroelectricity
using the water coming through the penstock 120 from the reservoir 110 to the river 160.
The gear pump 130 may be submerged in water as shown, or may not be submerged fully.
As shown in Figure IB, a platform 170 supports the gear pump unit 130 above the river 160
and a tailrace, or fourth leg 120D, extends out of gear pump unit 130 in to river 160. The
fourth leg 120D can be alternatively included on the submerged embodiment of Figure 1A.
[019] The gear pump unit 130 is scalable for pumping air, water, or mixtures of air
and water. The gear pump unit 130 is a positive displacement pump modeled on a Roots
supercharger. Compared to an automotive supercharger, the inlet and outlet ports are
adjusted for providing fluid flow with minimal or no compression. The rotor angles are also
adjusted for accommodating the velocity of the water, which is based on the available head.
Because the positive displacement pump can be optimized for fluid flow, it can move water,
air, or a mixture or water and air. It does not need a pure water stream to operate in turbine
or pump modes.
[020] The gear pump unit 130 is bidirectional, meaning it can receive water from
the reservoir 110 and expel it to a stream 160. The gear pump unit 130 can also siphon from
the stream 160 and pump fluid back to the reservoir 110. The gear pump unit 130 can also
operate in turbine mode to generate electricity.
[021] When operating in a forward pump mode, the gear pump unit 130 draws up
water from the reservoir 110 through leg 120A of penstock 120, and then supplies the same
to the leg 120C of penstock. More specifically, once the gear pump unit 130 is activated, it
may suck water up the leg 120A. The water travels through second leg 120B, which may be
embedded in dam 100 or fitted or retrofitted to the top of the dam 100, as shown. The
suction by gear pump unit 130 draws the water through third leg 120C. Once sufficient fluid
is drawn in to third leg 120C, then the gear pump unit 130 can cease sucking water in to the
penstock 120. So long as first leg 120A remains submerged in water, siphon effect will
supply water from the reservoir 110 to the gear pump unit 130 through the penstock 120.
Thus, gear pump unit 130 converts from forward pumping mode to turbine mode once
siphon effect is established. Should the need arise, gear pump unit 130 can operate in pump
mode even after siphon effect is established, for purposes such as pumping down reservoir
110.
[022] By employing a control module 150, the gear pump unit 130 can receive
electronic commands to operate in forward, reverse, or turbine modes. Inclusion of sensors
in the control module 150 enables feedback control.
[023] Although the placement of penstock 120 in FIG. 1A is shown to be around
the dam 100 and in open air, it is not be restricted as such. The penstock 120 can also be
placed below the water level, fully submerged. Thus the gear pump unit 130 and penstock
may be installed in the original dam 100 infrastructure, or it may be retrofitted, or it may be
installed directly in a river. It may replace original installation, or supplement its capacity.
[024] FIG. 2 shows the gear pump unit 130 in more detail. The gear pump unit 130
comprises a gear pump 131 and a generator 138. The gear pump 131 comprises an inlet 132,
rotors 133 and 134, a chamber 13 1A, and an outletl35. The gear pump unit 130 may be
submerged in the water. In addition, the gear pump unit 130 may be positioned partly out of
the water. The gear pump 131 is able to avoid cavitation effects by appropriate design of the
rotors in the housing. To pump out air and supply water through the gear pump unit 131, the
inlet 132 and the outlet 135 have ports that allow either water or air to travel through the
gear pump 131. The inlet 132 can comprise connectivity to portions of penstock 120. And,
the outlet 135 can comprise connectivity to a tailrace or fourth leg 120D of penstock to
submerge the expulsion point of spent water and to provide access to water during pump
mode. A pool can be provided near the outlet of the fourth leg 120D to facilitate the
submersion.
[025] Gear pump 131 is a positive displacement pump such as a Roots-type
supercharger. Preferably, an Eaton Corporation TWIN VORTICES SERIES TVS helical
rotor supercharger. As fluid enters through inlet 132, rotors 133 and 134 within the chamber
13 1A trap the fluid, air or water, between teeth of the rotors and the case 13 IB. Case 13 IB
encases rotors 133 and 134. As the rotors spin, fluid is expelled out outlet 135.
[026] Rotors 133, 134 may be identical in shape. Each rotor 133, 134 may have
multiple teeth 133A, 133B, 133C, 134A, 134B, 134C. For instance, each rotor in Figure 2
has three teeth, though other numbers, such as two or four teeth per rotor, can be used.
[027] By comparison, in conventional gear motors and pumps, there are 15-25
teeth. These conventional gears are 1-3 inches in diameter. Since the gears have a
relatively small diameter and high tooth count, the amount of water volume moved is small.
As a result, the power generated is be limited. In contrast, each rotor of the gear pump 131
has 3-4 teeth having a very large diameter of up to 40 inches. Due to the larger diameter, the
gear pump 13 1 of the present invention pumps a larger volume of water per tooth. In a large
hydroelectric application, gear pump unit 131 could comprise a low number of teeth with a
25-40 inch diameter gear. The teeth would have a low diametral pitch and would pump a
large volume of water per tooth. The lower number of teeth and larger volume increases the
displacement efficiency of the device. The sizes given are exemplary only, with size scaling
for application.
[028] Also by comparison, conventionally, there are approximately 15-25 teeth on a
gear motor or turbine. These teeth are 1-3 inches in diameter. Since the teeth have a
relatively small diameter, the amount of water volume displaced is small. As a result, the
power generated is limited. In contrast, each rotor of the gear pump 131 has 3-4 teeth
having a diameter of 3-6 inches. Due to the larger diameter, the gear pump 13 1 of the
present invention pumps a larger volume of water per tooth. In a large hydroelectric
application, gear pump unit 131 could comprise a low number of teeth with a 25-40 inch
diameter per tooth. The teeth would have a low diametral pitch and would pump a large
volume of water per tooth. The lower number of teeth and larger volume increases the
energy efficiency of the hydroelectric power generation. It also increases the speed of
rotation of the turbine, which reduces the cost of directly coupled generators.
[029] To further reduce cost of materials, the teeth can be made hollow. To help
improve efficiency the teeth can be cladded with a corrosion and wear resistant metallic
powder, such as Eaton Corporation's EATONITE. Other materials, including low friction
materials, improve aslo the efficiency. Thus, the rotors and or teeth can be coated with
materials including IN718, IN625, Cobalt Chrome, Stainless Steel, Titanium alloys, Nickel
based super alloys and coatings, ultra high strength steels, and metal matrix nano
composites. Thus, the gear pump 131 can be manufactured using laser welding, laserassisted
additive manufacturing, laser surface treatment and processing, additive
manufacturing (AM) techniques, and near net shape (NNS) techniques.
[030] Volume displacement devices such as gear pumps 131 have much better
air/water handling characteristics than traditional turbines. Unlike an Archimedes Screw, an
axial turbine system, or a centrifugal system, the gear pump 131 of this disclosure has dual
rotors and a helical structure to the rotor. This brings improved efficiency at low or high
head applications. In addition, unlike an Archimedes Screw, the twin vortices (TVS)
supercharger is housed, allowing it to leverage both impulse turbine characteristics, as by the
velocity of water turning the rotors, and reaction turbine characteristics, as by the pressure
build in the encasement. The gear pump 131 is also designed to pump bi-directionally,
which is not possible with Archimedes screw or prior art impulse or reaction turbines. The
TVS is also unaffected by orientation, location, cavitation, tail water, and tail size.
[031] FIG. 2 shows the rotor 133 having three teeth, 133A, 133B, and 133C.
Similarly, the rotor 134 has three teeth, 134A, 134B, and 135C. Other numbers of teeth are
possible. For example, the rotors can have between 2 and 5 teeth each. To facilitate rotor
mesh, the rotors 133 and 134 should have an identical number of teeth. Rotors 133, 134 can
be helical. The teeth can twist over the length of the rotors so that the respective teeth wrap
around their respective rotor. As an example, the teeth can twist 120 degrees over the length
of the rotor, or the teeth can twist 60 degrees over the length of the rotor. The degree of twist
varies based on the head of the application. The degree of twist is also a function of the
number of teeth, the outside diameter of the rotor, and the center distance of the rotors.
Ideally, the teeth will be optimized to have the largest possible twist for the given
application.
[032] In addition, each tooth has a diametral pitch, or angle that the tooth projects
from its rotor. Compared to an automotive supercharger, a gear pump for a water application
has lower diametral pitch. The teeth mesh as the rotors rotate. For example, teeth 133A,
133B, 133C of rotor 133 are twisted clockwise while the teeth 134A, 134B, 134C of rotor
134 are twisted counter-clockwise. Rotors 133, 134 are meshed together and geared to rotate
in opposite directions. Rotors 133, 134 rotate in response to commands from control module
150 for turbine mode or pump mode.
[033] The velocity of the water entering the gear pump 131 is a function of the
pressure of the water, which is related to the head of the source. The speed at which the
device will rotate is a function of the length of the rotor, twist of the teeth, and the pressure
of the available fluid. For a given pressure, the smaller the length of the rotor, the faster the
rotor will spin. Ideally, the design of the rotor is set up for maximum rotations per minute
(RPMs) at a free flow condition. However, because ideal conditions may not be the
predominant conditions, the rotor can also be designed for optimizing fluid flow during the
most common conditions. When the rotor is optimized, all the pressure in the water is
converted into velocity which is then turned into rotational velocity of the rotors.
[034] The size of the gear pump will be related to the amount of fluid flow
available. The length of rotors 133, 134 varies from application to application, based on the
head of the water supply. The size of the gear pump 13 1 is also determined by the length of
rotors 133, 134.
[035] The gear pump 131 functions as a turbine to generate electricity. This is
conducted with the gear pump 131 set in a turbine mode. In this mode, the water flows from
the reservoir 110 to the gear pump unit 130 via the penstock 120. The water flow entering
into the inlet 132 of gear pump 131 is trapped in a gap between adjacent teeth of rotor 133,
for example, between teeth 133A and 133B. The water flow is trapped in a gap between
adjacent teeth of rotor 134, for example, between teeth 134A and 134B. Trapped water flow
turns the gear pump 131. After turning teeth of the gear pump 131, the used up water flow is
carried out of the gear pump 131 through the outlet 135. The outlet 135 may be triangular
shaped to match the shape of the rotors 133, 134 for allowing easy exit.
[036] When water flow turns rotors of the gear pump 131, a shaft 136 that is
connected to the rotors via transmission gears rotates. The shaft 136 in turn rotates the
generator 138, which can be by direct coupling, or indirect coupling, such as via a pulley or
other torque transfer device. Figure 2 illustrates direct rotation of the generator, since the
shaft 136 is connected to the generator 138. The generator 138 is a device that converts
mechanical energy into electrical energy, and generator 138 may comprise a series of
magnets and wires (not shown) to induce a current in the wire to produce electricity. The
electricity can be fed to a power grid 137A for consumption and to a power storage device,
such as a battery 137B.
[037] The movement of water in turbine mode has been described. However, air,
or a mixture of air and water, can be moved through the gear pump 131 in a similar way. In
addition, the fluid flow direction can be reversed, so that water pumps from the stream 160
to the reservoir 110.
[038] The gear pump 131 can be set in a reverse pump mode. In the reverse pump
mode, the gear pump 131 functions as a pump to refill reservoir 110. A variety of control
electronics, such as wiring, sensors, transmit, receive, computing, computer readable storage
devices, programming, and actuator devices, can be devised to implement control
mechanism 150. Programming implements modes of operation to control gear pump 131,
such as to perform the pump function during off peak time and to perform the turbine mode
during peak time. As one example, electricity generated during turbine mode is supplied to
grid 137A during peak electricity use times. During off-peak times, electricity generated
using turbine mode is stored in battery 137B. The stored electricity is returned to power an
electric motor 138B affiliated via pulley hub 15 with input shaft and transmission gears of
rotors 133 and 134. As the electric motor 138B turns, it also turns the gear pump 131 in a
reverse direction. When the gear pump 13 1 is turned in a reverse direction, it moves water
back up to the reservoir 110. Because the gear pump 131 can move the water back up to the
reservoir 110, the necessity of having a separate pump is negated. As a result, the gear
pump unit 130 is constructed with less parts than traditional hydroelectric systems and in a
simplified manner. Many gating and diversion techniques are also avoided. The reverse
pump mode is usable with any of Figures 1A, IB, and 4. If the gear pump is not fully or
partially submerged in water, at least a tailrace such as fourth leg 120D is attached to the
outlet 135 or 235 and is submerged in water to enable suction of water from downstream for
transfer by the gear pump to upstream.
[039] Figure 3 illustrates one example of a TVS type supercharger manufactured by
Eaton Corporation in connection with generator 138 and motor 138B. With modification, the
TVS type supercharger may be used as gear pump 13 1. It is an axial input, radial output type
having a pulley hub 15 connected to an internal shaft, transmission gears, and rotors 133 and
134. Fluid enters inlet 132 and exits outlet 135. Outlet 135 is defined by openings 21, 23 and
25 in case 13 IB. Details of such a supercharger may be found in US patent 7,488,164,
incorporated herein by reference in its entirety. While not illustrated, a radial inlet, radial
output type supercharger may also be used as gear pump 13 1. In Figure 3, pulleys are used
to transfer rotational energy from the pulley hub 15 to generator 138, or from motor 138B to
pulley hub 15.
[040] To use the supercharger as a gear pump in pump or turbine mode,
modifications should be made to facilitate maximum efficiency. These changes are angle of
the rotors 133, 134 and timing of inlet 132 and outlet 135. The rotors should have a low
diametral pitch to enable large volumes of water to pass through the unit. The inlet 132,
outlet 135 and rotors must accommodate the incompressible nature of water and, for
example, the inlet 132 and outlet 135 port sizes are adjusted and made larger. And, it is
possible to adjust the port timing of the inlet 132 and outlet 135 for pump and turbine
functions.
[041] When in the pump mode, the twist angle of teeth is designed in consideration
of the velocity of water. Because of the tradeoffs in pressure at the inlet or outlet during
turbine or pump mode, the twist angle should be adjusted for a particular hydropower
generation system in view of the frequency of use of pump or turbine mode. Despite this
limitation, the operating range of the gear pump 13 1 is greater than traditional turbines
because the design of the gear pump 131 can handle variable flow rates.
[042] The "seal time" of the outlet should also be adjusted. The "seal time" refers
to the number of degrees that a volume of water moves through a particular phase while
trapped in between adjacent teeth of the rotor (herein referred to as control volume). When
moving the water, there are three phases to the operation: 1) "initial seal time" is the number
of degrees of rotation during which the control volume is exposed to the inlet port; 2)
"transfer seal time" is the number of degree of rotation during which the transfer volume is
sealed from inlet port; and 3) "outlet seal time" is the number of degrees during which the
transfer volume is exposed to the outlet port. In order to conduct the pumping function, the
seal time is changed to avoid compression of the water. One method to manipulate the seal
time is to reduce or increase the width of the inlet port. The exact method of changing
sealing time along with the appropriate seal time is determined to suit needs of a particular
hydropower generation system.
[043] The computing device 139 controls the gear pump unit 131 by commanding
that the control module 150 operate the gear pump 130 in one of turbine mode, suction
mode, or pump mode. The implementation of the computing device 139 may differ from
one hydroelectric power generation system to the other. For instance, the computing device
139 may be operated based on strict time. In other words, by setting a peak hour and offpeak
hour, the gear pump unit can strictly conduct a certain operation during the designated
time.
[044] Alternatively, the computing device 139 can operate to change the mode
based on feedback it receives. In view of this, gear pump unit 130 and computing device
139 can include a network of additional electronics such as an array of additional sensors.
The sensors could include, for example, electricity sensors in grid 137A and battery 137B,
water level sensors in the reservoir 110, velocity sensors in penstock 120, RPM (rotations
per minute) speed sensors in the gear pump 131, speed sensors in generator 138, and water
level sensors in stream 160. Such sensors can electronically communicate with a computing
device 139 having a processor, memory, and stored algorithms. The computing device 139
can emit control commands to the gear pump 131 to operate in passive (turbine), forward
(suction), or reverse (pump) modes. The computing device 139 can be located with the gear
pump 131, or remote from the gear pump with appropriate communication devices in place.
Based on feedback, such as low electricity in the battery, the gear pump 131 can operate in
suction mode to fill the penstock 120, and can then switch to turbine mode to charge the
battery. Or, if a water level sensor in reservoir 110 indicates low water level, the gear pump
131 can operate in pump mode to move water from stream 160 to the reservoir 110.
[045] The gear pump unit 130 can be constructed as a component of the
hydropower generation system 10 as described in FIG. 1A. In addition, the gear pump unit
130 can supplement an existing hydropower generation plant by being a modular
installation. In supplementing the existing hydropower generation plant, the gear pump 131
can simply replace the existing turbine to enhance the efficiency of the existing system.
Alternatively, the gear pump unit 130 can be simultaneously used with the existing turbine
and pump, as by being laid over the existing infrastructure.
[046] Figure IB illustrates another benefit of the modular design, which enables
easy servicing and maintenance. A platform 170 is installed at or near the water level of
river 160. The gear pump unit 130 and control module 150 are stationed on the platform
170. The gear pump 131 is serviceable and the control module 150 is easily updated. Being
externally mounted to the dam 100, it is not necessary to enter in to the dam 100 to service
the penstock 120 or gear pump unit 130. The light weight of the hollow rotors further
facilitates the modular design.
[047] Figure 4 shows another embodiment of the present invention. A gear pump
unit 230 may be placed in a small stream to generate electricity. The gear pump unit 230
may be a low head hydroelectric power generator. The gear pump unit 230 may receive
water from a water source 200 through an inlet 232. The water source 200 may be a canal or
fast flowing river or stream. The gear pump unit 230 comprises a gear pump 231 and a
generator 238. The gear pump 231 and the generator 238 may be connected to each other
through a shaft 236 or by a pulley or other mechanical coupling. The gear pump unit 230
may be constructed similar to the gear pump unit 130 as described using FIG. 2, with
additional modifications to accommodate the difference in fluid velocity in the low head
application, such as underwater placement of penstock 220A leading to inlet 232, and
inclusion of tailrace penstock 220D at outlet 235. The gear pump unit 230 may alternatively
include another fluid diversion mechanism than penstock, such as a tray like structure.
[048] The gear pump unit 230 can be completely submerged under the water level
of a flowing water source, or may be partially submerged. If fluid flow is not sufficient to
turn the turbine, power can be used to pump up the water source by operating in pump mode
and filling a reservoir structure. Thus, in the low head application it is particularly
advantageous to implement a combined generator/motor. However, when a reservoir is not
necessary, and fluid flow is sufficient, gear pump unit 230 can be used without a costly
structural base making it cost effective and portable.
[049] In the preceding specification, various preferred embodiments have been
described with reference to the accompanying drawings. It will, however, be evident that
various other modifications and changes may be made thereto, and additional embodiments
may be implemented, without departing from the broader scope of the invention as set forth
in the claims that follow. The specification and drawings are accordingly to be regarded in
an illustrative rather than restrictive sense.
[050] Other embodiments will be apparent to those skilled in the art from
consideration of the specification and practice of the disclosure. It is intended that the
specification and examples be considered as exemplary only, with the true scope and spirit
of the invention being indicated by the following claims.
CLAIMS:
1. A gear pump unit for hydroelectric power generation, comprising:
a gear pump (131) comprising:
a case (13 IB) comprising a fluid inlet (132) and an outlet (135);
a first rotor (133) in the case (13 IB), the first rotor comprising a first plurality
of radially spaced teeth (133A, 133B, 133C), wherein the first plurality of
radially spaced teeth wrap around the first rotor helically in a clockwise
direction;
a second rotor (134) in the case (13 IB), the second rotor comprising a second
plurality of radially spaced teeth (134A, 134B, 134C), wherein the second
plurality of radially spaced teeth wrap around the second rotor helically in a
counter-clockwise direction, and wherein the first plurality of teeth mesh with the
second plurality of teeth; and
a shaft (136) operatively connected to the first rotor (133) and to the second
rotor (134);
a generator (138) operatively connected to the shaft (136); and
a control module 150 operatively connected to the gear pump (131) and configured
to selectively rotate the first rotor in a first direction and to selectively rotate the second rotor
in a second direction, the control mechanism further configured to selectively reverse the
rotation direction of the first rotor and to selectively reverse the rotation direction of the
second rotor.
2. The gear pump unit of claim 1, wherein the gear pump (131) further comprises a
pulley hub (15) connected to a second end of the shaft (136), and wherein the gear pump
unit further comprises a pulley connected between the pulley hub (15) and the generator
(138).
3. The gear pump unit of claim 1, wherein respective gaps are formed between each of
the first plurality of teeth and between the second plurality of teeth, and wherein, when a
fluid is supplied to the gear pump, and when the first rotor and the second rotor rotate, a
fluid is displaced in each respective gap.
4. The gear pump unit of claim 1, wherein, when the control module (150) selectively
rotates the first rotor (133) in the first direction and selectively rotates the second rotor (134)
in the second direction, and when an inlet fluid is supplied to the inlet (132), the fluid moves
from the inlet (132) to the outlet (135) in respective gaps between the first plurality of
radially spaced teeth and in respective gaps between the second plurality of radially spaced
teeth, and wherein, when the control mechanism selectively reverses the rotation direction of
the first rotor and selectively reverses the rotation direction of the second rotor, and wherein
a tailrace fluid is supplied to the outlet (135), the tailrace fluid moves from the outlet (135)
to the inlet (132) in the respective gaps between the first plurality of radially spaced teeth
and in the respective gaps between the second plurality of radially spaced teeth.
5 The gear pump unit of claim 4, wherein the fluid is air, water, or a mixture of air and
water, and wherein the fluid moves in the gear pump (131) without cavitation.
6. The gear pump unit of claim 1, further comprising a penstock fluidly coupled to the
inlet (132).
7. The gear pump unit of claim 6, wherein the penstock comprises:
a first leg (120A) in a reservoir ( 110);
a second leg (120B) on a dam (100); and
a third leg (120C) connected to the gear pump (130).
8. The gear pump unit of claim 7, wherein the dam (100) comprises a platform (170),
wherein the gear pump (13 1) is mounted on the platform (170), and wherein the gear pump
(131) is not submerged.
9. The gear pump unit of claim 1, further comprising a computing device (139) in
communication with the control module (150), the computing device (139) further
comprising a network of sensors, a processor, a memory, and stored algorithms, the
computing device (139) configured to emit commands to the control module (150) to operate
the gear pump (130) in one of a turbine mode, a suction mode, or a pump mode.
10. The gear pump unit of claim 1, wherein the first plurality of radially spaced teeth
comprises teeth in the range of 2-5, and wherein the second plurality of radially spaced teeth
comprises teeth in the range of 2-5.
11. The gear pump unit of claim 10, wherein each tooth of the first plurality of radially
spaced teeth and each tooth of the second plurality of radially spaced teeth comprises a
diameter of 25 to 50 inches.
12. The gear pump unit of claim 1, wherein the gear pump is configured to move water,
air, and a mixture of water and air.
13. The gear pump unit of claim 1, wherein the gear pump (131) is an axial-input, radialoutlet
type supercharger.
14. The gear pump unit of claim 1, wherein each of the first plurality of radially spaced
teeth (133A, 133B, 133C) and each of the second plurality of radially spaced teeth (134A,
134B, 134C) are hollow.
15. A method of operating a hydroelectric power gear pump unit (130) comprising the
steps of:
supplying a fluid to an inlet (132) of a gear pump (131) case (13 IB);
moving the fluid through a chamber (13 1A) of the case (13 IB) by rotating a first
rotor (133) in the case (13 IB), the first rotor comprising a first plurality of radially spaced
teeth (133A, 133B, 133C);
moving the fluid through the chamber (13 1A) of the case (13 IB) by simultaneously
rotating a second rotor (134) in the case (13 IB), the second rotor comprising a second
plurality of radially spaced teeth (134A, 134B, 134C);
expelling the fluid through an outlet (135) of the gear pump case (13 IB);
generating electricity by coupling the rotational energy of the first rotor and the
rotational energy of the second rotor to a generator (138); and
reversing the rotating of the first rotor and the second rotor to move the fluid from
the outlet (135) to the inlet (132).
16. The method of claim 15, wherein the step of supplying the fluid to the inlet further
comprises supplying the fluid to a first leg (120A) of a penstock, and wherein the method of
operating a hydroelectric power gear pump unit further comprises the step of operating the
gear pump (13 1) to siphon the fluid in to the first leg (120A) of the penstock.
17. The method of claim 15, wherein the step of reversing the rotating of the first rotor
and the second rotor further comprises the step of operating the gear pump (131) to siphon
the fluid in to the gear pump (131).
18. The method of any one of claims 15-17, wherein the first plurality of radially spaced
teeth wrap around the first rotor helically in a clockwise direction, and wherein the second
plurality of radially spaced teeth wrap around the second rotor helically in a counter
clockwise direction, and wherein the first plurality of teeth mesh with the second plurality of
teeth.