CA2761843A1 - System for discharging water to a turbine to generate power - Google Patents
System for discharging water to a turbine to generate power Download PDFInfo
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- CA2761843A1 CA2761843A1 CA2761843A CA2761843A CA2761843A1 CA 2761843 A1 CA2761843 A1 CA 2761843A1 CA 2761843 A CA2761843 A CA 2761843A CA 2761843 A CA2761843 A CA 2761843A CA 2761843 A1 CA2761843 A1 CA 2761843A1
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- Prior art keywords
- water
- valve
- column
- turbine
- power
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Classifications
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- 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
- F03B1/00—Engines of impulse type, i.e. turbines with jets of high-velocity liquid impinging on blades or like rotors, e.g. Pelton wheels; Parts or details peculiar thereto
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- 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
- F03B13/00—Adaptations of machines or engines for special use; Combinations of machines or engines with driving or driven apparatus; Power stations or aggregates
- F03B13/06—Stations or aggregates of water-storage type, e.g. comprising a turbine and a pump
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- 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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- 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
- Y02E10/30—Energy from the sea, e.g. using wave energy or salinity gradient
-
- 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
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/16—Mechanical energy storage, e.g. flywheels or pressurised fluids
Abstract
A system for discharging water to a turbine to generate power, the system including a rigid container for containing water, a valve for discharging water from the lower end of the rigid container, and a turbine to be driven by discharged water.
The rigid container is configured to contain a water column having a height sufficient to cause elastic compression of the water and to accommodate propagation of compression waves in the water column. The valve has an open/close cycle with a time duration in the range of about 10 to about 200 milliseconds, to facilitate generation of compression waves in the water column, and opening and closing of the valve is dynamically controlled by a feedback controller.
The rigid container is configured to contain a water column having a height sufficient to cause elastic compression of the water and to accommodate propagation of compression waves in the water column. The valve has an open/close cycle with a time duration in the range of about 10 to about 200 milliseconds, to facilitate generation of compression waves in the water column, and opening and closing of the valve is dynamically controlled by a feedback controller.
Description
SYSTEM FOR DISCHARGING WATER TO A TURBINE
TO GENERATE POWER
Cross-Reference to Related Application The present disclosure claims priority from U.S. provisional patent application no. 61/178,250, filed May 14, 2009, the entirety of which is hereby incorporated by reference.
Technical Field The present disclosure is generally related to the field of power generation.
In particular, the present disclosure relates to hydropower generation.
Background Hydropower generation presents with several challenges:
1) The apparently diminishing amount of water available from lakes and rivers for hydropower generation.
TO GENERATE POWER
Cross-Reference to Related Application The present disclosure claims priority from U.S. provisional patent application no. 61/178,250, filed May 14, 2009, the entirety of which is hereby incorporated by reference.
Technical Field The present disclosure is generally related to the field of power generation.
In particular, the present disclosure relates to hydropower generation.
Background Hydropower generation presents with several challenges:
1) The apparently diminishing amount of water available from lakes and rivers for hydropower generation.
2) The location for clean hydropower generation is limited. Generation facilities are generally located where significant amounts of water are available.
3) Dams are often expensive to construct and maintain, and tend to be highly regulated, foe example, for environmental issues.
4) Water irrigation to cities and to farms may use tremendous amounts of electricity and may be costly.
A solution to address at least some of these and other challenges is desirable.
Summary In some aspects, the present disclosure describes a system for discharging water to a turbine to generate power. In the disclosed system, molecular reaction is a generally uni-directional compression force, such as the weight of a liquid confined in an open top rigid container and is volumetric with the wall of the rigid container acting as a compression force. Thus, the total compression force exercised upon the liquid, is not only the weight of the liquid but also the restrictive force of the wall of the container against the liquid which increases the stored compression force.
Generally, the disclosed system may provide greater efficiency in flowing water (e.g., by decreasing water loss) through a turbine generator, compared to conventional hydropower generators.
The total stored compression force of a liquid in a container may be converted into kinetic energy as a jet, if the opening allowing the liquid to expand occurs with sufficient speed that the decompression wave of the liquid can pass through the opening before the decompression wave is able to reverse the direction of expansion.
Use of the compression of water may allow the construction of power generating systems that reduces the amount of falling water required to generate the same power as hydraulic turbines using continuous flow of water.
The disclosed system may not require a large amount of water to flow through it in order to provide large amounts of power. The reactor pulses the water, for example around six to nine times a second (this rate may be higher or lower), through a high speed valve and thus propels a turbine to generate power. Power may be thus generated using less water than a conventional water turbine, or more power may be generated for the same water consumption as a conventional water turbine.
The system may be equipped with one or more water pumps that pump water from the bottom of the system to the top. Once water flows through the pipe and through the valve, it may be collected at a lower reservoir and may be then pumped up to the top to be run through the system again. This may allow the system to be installed anywhere regardless of the location of a mass water supply. Pumping of water back to the top of the system may be powered by off-peak power or excess power from other power sources. Thus, the system may, for example, serve to store energy (in the form of a compressed water column) at off-peak hours and relatively efficiently convert the stored energy into useable power during peak hours.
The system may be installed on the bank of a river or lake without installation of a dam, though the system may also be used with a dam in some aspects. The system may only need a minimal flow rate of water and only the required flow may be diverted towards the intake pipe and used in the system. Once the water has flowed through the valve, the water may be released back into the main stream of the river or back into the lake.
The system may be used to pump water inland from water supplies located far from highly populated areas. The system may provide at least some of its own power to run all the pumps required, and may use the same water that is being transported to flow through the system and generate at least some of the power. This may reduce or eliminate the cost of electricity needed to power the pumps. The water pumps may also be powered by relatively inexpensive power, for example off-peak or excess power from other power sources. The system may thus, for example, serve to store energy (in the form of a compressed water column) during off-peak hours and relatively efficiently convert this to useful power during peak hours.
In some aspects, there is disclosed a system for discharging water to a turbine to generate power, the system comprising: a rigid container for containing contain a water column having a height sufficient to cause elastic compression of water in the water column and to accommodate propagation of compression waves in the water column; a valve attached to the rigid container for intermittently discharging water at a lower end of the rigid container, the valve having an open/close cycle with a time duration in the range of about 10 to about 200 milliseconds, to facilitate generation of compression waves in the water column, wherein opening and closing of the valve is dynamically controlled by a feedback controller; and a turbine positioned adjacent to the valve, the valve being directed to periodically discharge water to drive the turbine.
In some aspects, the system further comprises a water pump for pumping discharged water into the rigid container.
In some aspects, the system has two or more rigid containers, each having a respective valve, the valves being directed at one or more turbines for driving the one or more turbines.
In some aspects, there is disclosed a valve for a container of liquid comprising:
a piston adapted to fit in an opening in the container, the opening being sealed when the piston is in a closed position and opened when the piston is in an opened position;
and an arm for driving opening and closing of the piston; wherein the valve has a high rate of opening and closing.
In some aspects, the valve comprises an elastic member to assist in driving opening and closing of the piston.
In some aspects, the valve is adapted to fit in a container having a wide bowl around the opening.
In some aspects, there is disclosed a method of discharging water to a turbine to generate power, the method comprising: compressing a water column; and intermittently discharging water from the water column to drive a turbine for generating power, the water being discharged in a cycle having a time duration of about 10 to about 200 milliseconds, to facilitate generation of compression waves in the water column; wherein the water column has a height sufficient to cause elastic compression of water and to accommodate propagation of compression waves in the water column.
In some aspects, the method further comprises returning discharged water to the water column.
Brief Description of Figures Figure 1 is a schematic diagram of an example of the disclosed system, in accordance with some aspects of the present disclosure;
Figure 2 is a schematic diagram of an example of the disclosed system having two water columns, in accordance with some aspects of the present disclosure;
Figure 3 is a schematic diagram of another configuration for the system of Figure 2;
Figure 4 is a close-up schematic diagram of the valve and turbine of the system of Figure 3;
Figure 5 is a schematic diagram of an example of the disclosed system having three water columns, in accordance with some aspects of the present disclosure;
A solution to address at least some of these and other challenges is desirable.
Summary In some aspects, the present disclosure describes a system for discharging water to a turbine to generate power. In the disclosed system, molecular reaction is a generally uni-directional compression force, such as the weight of a liquid confined in an open top rigid container and is volumetric with the wall of the rigid container acting as a compression force. Thus, the total compression force exercised upon the liquid, is not only the weight of the liquid but also the restrictive force of the wall of the container against the liquid which increases the stored compression force.
Generally, the disclosed system may provide greater efficiency in flowing water (e.g., by decreasing water loss) through a turbine generator, compared to conventional hydropower generators.
The total stored compression force of a liquid in a container may be converted into kinetic energy as a jet, if the opening allowing the liquid to expand occurs with sufficient speed that the decompression wave of the liquid can pass through the opening before the decompression wave is able to reverse the direction of expansion.
Use of the compression of water may allow the construction of power generating systems that reduces the amount of falling water required to generate the same power as hydraulic turbines using continuous flow of water.
The disclosed system may not require a large amount of water to flow through it in order to provide large amounts of power. The reactor pulses the water, for example around six to nine times a second (this rate may be higher or lower), through a high speed valve and thus propels a turbine to generate power. Power may be thus generated using less water than a conventional water turbine, or more power may be generated for the same water consumption as a conventional water turbine.
The system may be equipped with one or more water pumps that pump water from the bottom of the system to the top. Once water flows through the pipe and through the valve, it may be collected at a lower reservoir and may be then pumped up to the top to be run through the system again. This may allow the system to be installed anywhere regardless of the location of a mass water supply. Pumping of water back to the top of the system may be powered by off-peak power or excess power from other power sources. Thus, the system may, for example, serve to store energy (in the form of a compressed water column) at off-peak hours and relatively efficiently convert the stored energy into useable power during peak hours.
The system may be installed on the bank of a river or lake without installation of a dam, though the system may also be used with a dam in some aspects. The system may only need a minimal flow rate of water and only the required flow may be diverted towards the intake pipe and used in the system. Once the water has flowed through the valve, the water may be released back into the main stream of the river or back into the lake.
The system may be used to pump water inland from water supplies located far from highly populated areas. The system may provide at least some of its own power to run all the pumps required, and may use the same water that is being transported to flow through the system and generate at least some of the power. This may reduce or eliminate the cost of electricity needed to power the pumps. The water pumps may also be powered by relatively inexpensive power, for example off-peak or excess power from other power sources. The system may thus, for example, serve to store energy (in the form of a compressed water column) during off-peak hours and relatively efficiently convert this to useful power during peak hours.
In some aspects, there is disclosed a system for discharging water to a turbine to generate power, the system comprising: a rigid container for containing contain a water column having a height sufficient to cause elastic compression of water in the water column and to accommodate propagation of compression waves in the water column; a valve attached to the rigid container for intermittently discharging water at a lower end of the rigid container, the valve having an open/close cycle with a time duration in the range of about 10 to about 200 milliseconds, to facilitate generation of compression waves in the water column, wherein opening and closing of the valve is dynamically controlled by a feedback controller; and a turbine positioned adjacent to the valve, the valve being directed to periodically discharge water to drive the turbine.
In some aspects, the system further comprises a water pump for pumping discharged water into the rigid container.
In some aspects, the system has two or more rigid containers, each having a respective valve, the valves being directed at one or more turbines for driving the one or more turbines.
In some aspects, there is disclosed a valve for a container of liquid comprising:
a piston adapted to fit in an opening in the container, the opening being sealed when the piston is in a closed position and opened when the piston is in an opened position;
and an arm for driving opening and closing of the piston; wherein the valve has a high rate of opening and closing.
In some aspects, the valve comprises an elastic member to assist in driving opening and closing of the piston.
In some aspects, the valve is adapted to fit in a container having a wide bowl around the opening.
In some aspects, there is disclosed a method of discharging water to a turbine to generate power, the method comprising: compressing a water column; and intermittently discharging water from the water column to drive a turbine for generating power, the water being discharged in a cycle having a time duration of about 10 to about 200 milliseconds, to facilitate generation of compression waves in the water column; wherein the water column has a height sufficient to cause elastic compression of water and to accommodate propagation of compression waves in the water column.
In some aspects, the method further comprises returning discharged water to the water column.
Brief Description of Figures Figure 1 is a schematic diagram of an example of the disclosed system, in accordance with some aspects of the present disclosure;
Figure 2 is a schematic diagram of an example of the disclosed system having two water columns, in accordance with some aspects of the present disclosure;
Figure 3 is a schematic diagram of another configuration for the system of Figure 2;
Figure 4 is a close-up schematic diagram of the valve and turbine of the system of Figure 3;
Figure 5 is a schematic diagram of an example of the disclosed system having three water columns, in accordance with some aspects of the present disclosure;
5 Figure 6 is a schematic diagram of a valve suitable for an example of the disclosed system, in accordance with some aspects of the present disclosure;
Figure 7 is a schematic diagram of a turbine suitable for an example of the disclosed system, in accordance with some aspects of the present disclosure;
and Figure 8 is a table showing example results achieved with an example prototype of the disclosed system.
Detailed Description A system for discharging water to a turbine to generate power is disclosed.
Although the present disclosure makes reference to examples, these are not intended to be limiting. Theories of operation are also presented in this disclosure, which are not intended to be binding or limiting, and the function and operation of the system are not dependent on these theories. Such theories are presented merely to assist one skilled in the art in understanding the embodiments disclosed.
In the mid 1700's, Leonhard Euler and Daniel Bernoulli, who were mathematicians and not hydraulic engineers, indicated that to make their equation of flowing water energy and conservation feasible, they considered water to be incompressible. Bernoulli ignored the stored elastic compression as a source of energy because he studied water in continuous flow and he did not have the instruments available today. To develop a new water power technology, the bulk modulus of elasticity for water is included. The motion of water caused from the stored elastic compression is included in the calculations for the amount of energy produced.
The jets of water develop an elastic reaction to the compression of the water with a moment of a stationary condition between the jets to allow the elastic compression to occur.
Figure 7 is a schematic diagram of a turbine suitable for an example of the disclosed system, in accordance with some aspects of the present disclosure;
and Figure 8 is a table showing example results achieved with an example prototype of the disclosed system.
Detailed Description A system for discharging water to a turbine to generate power is disclosed.
Although the present disclosure makes reference to examples, these are not intended to be limiting. Theories of operation are also presented in this disclosure, which are not intended to be binding or limiting, and the function and operation of the system are not dependent on these theories. Such theories are presented merely to assist one skilled in the art in understanding the embodiments disclosed.
In the mid 1700's, Leonhard Euler and Daniel Bernoulli, who were mathematicians and not hydraulic engineers, indicated that to make their equation of flowing water energy and conservation feasible, they considered water to be incompressible. Bernoulli ignored the stored elastic compression as a source of energy because he studied water in continuous flow and he did not have the instruments available today. To develop a new water power technology, the bulk modulus of elasticity for water is included. The motion of water caused from the stored elastic compression is included in the calculations for the amount of energy produced.
The jets of water develop an elastic reaction to the compression of the water with a moment of a stationary condition between the jets to allow the elastic compression to occur.
To better understand the disclosed system, time and elasticity may be considered when applying the fundamentals of motion with water. Relationships that assist in implementing or understanding this new technology may include equations relating to force, weight, and kinetic energy.
Force may be defined as the unbalanced agent which changes the motion of a body. Simplified, force, F, is generally equal to the mass, m, of the body multiplied by the acceleration, a, that the mass develops.
This equation is applicable to mass that is motionless. For example, the weight, W, of an object is a force relative to the mass of the object multiplied by the acceleration due to gravity, g. This means the object can move downwards if it was free tofall: F=W=m=g A body in motion has kinetic energy. The kinetic energy, Ek, is defined by the distance, or displacement, s, over which the force moves: Ek = F = s = ma = s, or traditionally: Ek ='/2mv2 for any moving body.
With waterpower, acceleration is automatically considered to be that of falling water due to gravity: a = g. The equation for velocity, v, then becomes: v = g = t, where t is the time of the vertical fall of distance h. When using h in the calculation of t: t = h / (v/2). When t is substituted into the velocity equation, the equation becomes:
v = g = h / (v/2) and thus v2= 2gh. Therefore, for an object moving in free fall, the energy produced is Ek = %2mv2 ='/2m = 2gh = mgh To avoid the `force of habit' in hydraulics, it may be clarified that the acceleration in the force equation, F = ma, can be different and higher than the acceleration provided by gravity, g = 9.81 m/s2, even in water power.
A liquid confined in a rigid container when subjected to a compression force, converts and stores the compression force into elastic deformation within its own mass and makes restitution of the compression force by expansion (decompression), either by expelling from the container the volume equal to that of the elastic deformation or pushing out any selected area of the container wall when and where the resistance to compression force is less than that of the stored compression forces.
Force may be defined as the unbalanced agent which changes the motion of a body. Simplified, force, F, is generally equal to the mass, m, of the body multiplied by the acceleration, a, that the mass develops.
This equation is applicable to mass that is motionless. For example, the weight, W, of an object is a force relative to the mass of the object multiplied by the acceleration due to gravity, g. This means the object can move downwards if it was free tofall: F=W=m=g A body in motion has kinetic energy. The kinetic energy, Ek, is defined by the distance, or displacement, s, over which the force moves: Ek = F = s = ma = s, or traditionally: Ek ='/2mv2 for any moving body.
With waterpower, acceleration is automatically considered to be that of falling water due to gravity: a = g. The equation for velocity, v, then becomes: v = g = t, where t is the time of the vertical fall of distance h. When using h in the calculation of t: t = h / (v/2). When t is substituted into the velocity equation, the equation becomes:
v = g = h / (v/2) and thus v2= 2gh. Therefore, for an object moving in free fall, the energy produced is Ek = %2mv2 ='/2m = 2gh = mgh To avoid the `force of habit' in hydraulics, it may be clarified that the acceleration in the force equation, F = ma, can be different and higher than the acceleration provided by gravity, g = 9.81 m/s2, even in water power.
A liquid confined in a rigid container when subjected to a compression force, converts and stores the compression force into elastic deformation within its own mass and makes restitution of the compression force by expansion (decompression), either by expelling from the container the volume equal to that of the elastic deformation or pushing out any selected area of the container wall when and where the resistance to compression force is less than that of the stored compression forces.
System In addition to the weight of the water used in traditional hydropower generation, the technology of the presently disclosed system introduces into standard power calculations the reaction of water to compression. This reaction of water to compression includes the introduction of the elasticity of water, a property often ignored by traditional technology, which when applied may be useful for hydropower generation.
Figure 1 shows an example general configuration for a system for discharging water to a turbine to generate power. The system includes a rigid container, such as a penstock, for a column of water, a valve for periodically discharging the water from the lower end of the rigid container, and a turbine positioned to be driven by water discharged from the valve for generating power.
In this example configuration, water (which may be provided by a continuous or periodic input) in the rigid container experiences compressive forces due to gravity, including stationary compression (Cw) and operational compression (which may be referred to as a "water hammer") (CH). The operational compression typically propagates in a wave-like manner (i.e., in the form of a compression wave), which may be oscillatory, cyclic or intermittent. The stationary compression reduces the volume of water elastic compression qw and the operational compression reduces the volume of water by elastic compression qH. The elastic compression results in energy stored in the water column (qw + qH). The water is released in intermittent jets by the opening/closing of a valve B (e.g., a super fast jet valve), which is controlled by a valve operation activator Ce (which may be an electrical or mechanical control, for example). The water jets provide kinetic energy K to drive a turbine C, powering a generator Me. The generator produces electrical power EW. In the example shown, portions of Ew are directed to power the valve operation activator and a water return pump Pe, with the remaining being net useful power NMe.
In some examples the valve operation activator and/or the water return pump may be powered using another source of power, including, for example, power from solar power, wind turbines, gas, diesel, natural gas or any other suitable means, and which may be off-peak or less expensive power. This may allow a larger portion of the power generated by the water jets to be delivered as useful energy.
The container may be any suitable shape, such as cylindrical, for example having a cross-sectional area A and a height H. The container may have a varying wall width, for example it may have thicker walls near the bottom. For the high water column, the suitable dimensions of the column of water may vary or be dependent on the amount of power needed. The column may have a sufficient capacity and height for the water to develop, in static condition between jets, a useful amount of stored elastic compression energy to transfer to the jet of water, coming from the valve, the acceleration for developing a large value of energy per volume of water in a very short period of time.
The valve may be a relatively fast open/close water valve. For example, the valve may open at a fast enough rate that an open/close cycle may be completed in around 2/10 of a second or less. Such a valve may be used to release the stored elastic compression energy in a penstock or column of water by accelerating a water jet and develop, intentionally, a controlled high level water hammer effect. In some aspects, the valve may be a super fast jet valve (SFJV). For the SFJV, there is a liquid OPEN/CLOSE control valve that may operate at a rapid speed. The valve may open fast enough to have the power benefit of the water's elastic expansion, compressed under its own weight and a water hammer effect, before the energy would be wasted by the water bouncing up and down in the column. Operation of the SFJV may be controlled by a valve operation activator. The SFJV may be any valve capable of an open/close cycle on the order of milliseconds, for example in the range of about 10 to about 200 milliseconds. The SFJV may be any valve capable of sustaining such rapid open/close cycles repeatedly (e.g., about 31 trillion or more repeated cycles) over a suitable lifetime (e.g., about 20 years).
The turbine may be any suitable turbine. The turbine may be designed to optimize power output when the turbine is driven by water jets from the valve.
The power output from the turbine may be transmitted for useful consumption. In some examples, a portion of the power output may be diverted to operate at least some aspects of the disclosed system.
The system may additionally include a water return pump for returning ejected water back to the rigid container, to recover the height of the water column.
In some examples, power for the return pump may be at least partially provided by another power source, for example off-peak, inexpensive or excess power from another power source (e.g., power from solar power, wind turbines, gas, diesel, natural gas or any other suitable means). In this way, the system may, for example, take advantage of inexpensive or excess off-peak power to store energy in the form of the water column, and relatively efficiently convert this to useful energy (by driving the water turbine) during peak hours. In some aspects, in place of or in addition to the return pump, water may be introduced into the column from some other source, such as a stream, lake, reservoir, dam, water tank and the like, to recover the height of the water column.
A brief description of the function of the water column in the system is provided below.
Consider that: Water pressure at bottom = pgh Water pressure at top = 0.00 When the valve, such as the SFJV at the bottom of the column of water is opened:
1) The pressure locally at the valve opening becomes zero.
2) The energy stored in the water in the form of elastic compression is instantaneously released.
3) The drop in pressure is transmitted upwards through the tank as a negative pressure wave, as water exudes through the valve nozzle.
4) As the negative pressure wave moves through the tank, which may be at the speed of sound, the release of elastic energy takes place over a short period of time.
5) Due to the small size of the valve orifice, the released energy is concentrated in a relatively small mass of water discharged at a high speed.
6) After a short time, when the rate of release of the kinetic energy of the water jet has been reduced, the valve closes. The entire cycle from valve opening to 5 valve closing may take about 1/10 of a second. This time may be longer or shorter as suitable.
7) Meanwhile, the negative compression wave is reflected as a positive compression wave from the top of the column back towards the valve. In combination with the restored gravitational pressure at this location due to the 10 valve being now closed, this reflection creates a water hammer overpressure on the valve.
8) The valve is re-opened and the cycle is repeated.
In operation, it is believed that gravity acts on the water column in the rigid container and develops two compression forces - a stationary compression Cw and an operational compression (a water hammer) CH. Cw reduces the volume of water by qW
elastic compression. CH reduces the volume of water by qH elastic compression.
This is believed to store energy in the form of elastic deformation.
Stationary water is compressed under its own weight and stores elastic deformation energy that can be released in the form of a jet of discharged water. The power of the water hammer may increase the velocity of the water jet discharged from the valve and useful power may be output, such as in the form of a pulse or stream of water. The stored elastic energy may be renewed after it is discharged, by closing the valve and recovering the pressure at the bottom of the water column, between the release of two consecutive water jets discharged from the valve, which may allow a fast cycle sequence of power output through bursts of fluid.
1) The column of water of suitable height in a rigid container in a stationary condition can store the elastic compression energy of the water compressed under its own weight. In the example of a column of water held in a rigid cylindrical container, the width of the column may, for example, range from about 700mm to about 8m, in particular from about 746mm to about 7.62m.
The height of the column may, for example, be from about 60m to about 90m.
Other dimensions may be suitable, for example the diameter of the container may be about 50mm and up, and the height or head of the column may be about 10m and up. These dimensions may be varied, for example depending on the amount of power to be generated and/or depending on where the system is installed.
2) The stored elastic compression energy creates a volume reduction that can be suddenly let to expand to the normal volume, by allowing the water to push through the valve located at the bottom of the column. This creates a water mass in the form of a jet discharged from the valve. When the water is allowed to expand suddenly in this manner, it creates waves of `pressure drop';
starting at the valve and moving upwards, layer by layer, to the top of the column.
When the pressure drop wave reaches the top, the pressure of the water has been released through the valve. To limit the water loss when at a low pressure, the valve has to close fast, for example at the moment when the lowest or near lowest pressure in the column is reached (closing of the valve may not be exactly at the lowest pressure, for example due to response time of the control system). The amount of water discharged in each water jet may be dependent on the dimensions of the water column and the open/close speed of the valve. For example, a jet of water may discharge from about 1.2L to about 3.6L of water over a duration of about 1/20 to about 1/10 of a second.
3) When the valve closes, the pressure in the column begins to rise due to the gravity and water hammer effect creating a downward over pressure, due to the closing of the valve. The over pressure is higher than the static pressure when the valve is open.
4) When the overpressure reaches the peak or near peak, the valve is opened again (opening of the valve may not be exactly at the peak of the overpressure, for example due to response time of the control system), creating a stronger jet of water than the one developed by the static pressure in the column. The rhythmic open/close of the valve releases an ongoing series of intermittent jets.
5) The overpressure of the gravity and water hammer may help to increase the stored elastic compression energy.
6) The mass of the intermittent water jet expelled through the opening valve, by the force of weight, and the expansion, caused by the discharge of stored elastic compression energy, gains a generally higher velocity than the water that would have been expelled by the force of weight alone through the same opening. The higher velocity of the water jets also tends to be created in a shorter time.
Like some phenomena related to elasticity, the element of time may cause reaction changes. There may be challenges in analyzing water's elastic reaction due to changes from one time frame to another. By addressing the time element when studying water power, it was discovered that time is a factor for the conversion of elastic compression energy into kinetic energy, and from kinetic energy into power.
When considering the force experienced by the water in the column, it was found that the acceleration due to gravity, g, and the weight of the body, mg, does not disappear; it acts as a compression force, C. The would-be kinetic energy is transformed into stored elastic energy, K, of deformation, or compression in this case, in the order of. K = mC2 / 2e, where e is the bulk modulus of elasticity for water. This energy storage may be a result of a reduction of volume which is a temporary state in the disclosed system. When the water is free to move by the fast opening of the valve, the stored elastic energy becomes kinetic energy and is joined by the energy of the down moving force of the weight from the water exiting the container. The total kinetic energy of the jet of water is: Ejet = Ek + K = mgh + mC2 / 2e The overpressure of the water hammer increases the stored elastic energy of compression and converts it to kinetic energy so that it increases the velocity of the jet of water well above that of falling weight.
Figure 1 shows an example general configuration for a system for discharging water to a turbine to generate power. The system includes a rigid container, such as a penstock, for a column of water, a valve for periodically discharging the water from the lower end of the rigid container, and a turbine positioned to be driven by water discharged from the valve for generating power.
In this example configuration, water (which may be provided by a continuous or periodic input) in the rigid container experiences compressive forces due to gravity, including stationary compression (Cw) and operational compression (which may be referred to as a "water hammer") (CH). The operational compression typically propagates in a wave-like manner (i.e., in the form of a compression wave), which may be oscillatory, cyclic or intermittent. The stationary compression reduces the volume of water elastic compression qw and the operational compression reduces the volume of water by elastic compression qH. The elastic compression results in energy stored in the water column (qw + qH). The water is released in intermittent jets by the opening/closing of a valve B (e.g., a super fast jet valve), which is controlled by a valve operation activator Ce (which may be an electrical or mechanical control, for example). The water jets provide kinetic energy K to drive a turbine C, powering a generator Me. The generator produces electrical power EW. In the example shown, portions of Ew are directed to power the valve operation activator and a water return pump Pe, with the remaining being net useful power NMe.
In some examples the valve operation activator and/or the water return pump may be powered using another source of power, including, for example, power from solar power, wind turbines, gas, diesel, natural gas or any other suitable means, and which may be off-peak or less expensive power. This may allow a larger portion of the power generated by the water jets to be delivered as useful energy.
The container may be any suitable shape, such as cylindrical, for example having a cross-sectional area A and a height H. The container may have a varying wall width, for example it may have thicker walls near the bottom. For the high water column, the suitable dimensions of the column of water may vary or be dependent on the amount of power needed. The column may have a sufficient capacity and height for the water to develop, in static condition between jets, a useful amount of stored elastic compression energy to transfer to the jet of water, coming from the valve, the acceleration for developing a large value of energy per volume of water in a very short period of time.
The valve may be a relatively fast open/close water valve. For example, the valve may open at a fast enough rate that an open/close cycle may be completed in around 2/10 of a second or less. Such a valve may be used to release the stored elastic compression energy in a penstock or column of water by accelerating a water jet and develop, intentionally, a controlled high level water hammer effect. In some aspects, the valve may be a super fast jet valve (SFJV). For the SFJV, there is a liquid OPEN/CLOSE control valve that may operate at a rapid speed. The valve may open fast enough to have the power benefit of the water's elastic expansion, compressed under its own weight and a water hammer effect, before the energy would be wasted by the water bouncing up and down in the column. Operation of the SFJV may be controlled by a valve operation activator. The SFJV may be any valve capable of an open/close cycle on the order of milliseconds, for example in the range of about 10 to about 200 milliseconds. The SFJV may be any valve capable of sustaining such rapid open/close cycles repeatedly (e.g., about 31 trillion or more repeated cycles) over a suitable lifetime (e.g., about 20 years).
The turbine may be any suitable turbine. The turbine may be designed to optimize power output when the turbine is driven by water jets from the valve.
The power output from the turbine may be transmitted for useful consumption. In some examples, a portion of the power output may be diverted to operate at least some aspects of the disclosed system.
The system may additionally include a water return pump for returning ejected water back to the rigid container, to recover the height of the water column.
In some examples, power for the return pump may be at least partially provided by another power source, for example off-peak, inexpensive or excess power from another power source (e.g., power from solar power, wind turbines, gas, diesel, natural gas or any other suitable means). In this way, the system may, for example, take advantage of inexpensive or excess off-peak power to store energy in the form of the water column, and relatively efficiently convert this to useful energy (by driving the water turbine) during peak hours. In some aspects, in place of or in addition to the return pump, water may be introduced into the column from some other source, such as a stream, lake, reservoir, dam, water tank and the like, to recover the height of the water column.
A brief description of the function of the water column in the system is provided below.
Consider that: Water pressure at bottom = pgh Water pressure at top = 0.00 When the valve, such as the SFJV at the bottom of the column of water is opened:
1) The pressure locally at the valve opening becomes zero.
2) The energy stored in the water in the form of elastic compression is instantaneously released.
3) The drop in pressure is transmitted upwards through the tank as a negative pressure wave, as water exudes through the valve nozzle.
4) As the negative pressure wave moves through the tank, which may be at the speed of sound, the release of elastic energy takes place over a short period of time.
5) Due to the small size of the valve orifice, the released energy is concentrated in a relatively small mass of water discharged at a high speed.
6) After a short time, when the rate of release of the kinetic energy of the water jet has been reduced, the valve closes. The entire cycle from valve opening to 5 valve closing may take about 1/10 of a second. This time may be longer or shorter as suitable.
7) Meanwhile, the negative compression wave is reflected as a positive compression wave from the top of the column back towards the valve. In combination with the restored gravitational pressure at this location due to the 10 valve being now closed, this reflection creates a water hammer overpressure on the valve.
8) The valve is re-opened and the cycle is repeated.
In operation, it is believed that gravity acts on the water column in the rigid container and develops two compression forces - a stationary compression Cw and an operational compression (a water hammer) CH. Cw reduces the volume of water by qW
elastic compression. CH reduces the volume of water by qH elastic compression.
This is believed to store energy in the form of elastic deformation.
Stationary water is compressed under its own weight and stores elastic deformation energy that can be released in the form of a jet of discharged water. The power of the water hammer may increase the velocity of the water jet discharged from the valve and useful power may be output, such as in the form of a pulse or stream of water. The stored elastic energy may be renewed after it is discharged, by closing the valve and recovering the pressure at the bottom of the water column, between the release of two consecutive water jets discharged from the valve, which may allow a fast cycle sequence of power output through bursts of fluid.
1) The column of water of suitable height in a rigid container in a stationary condition can store the elastic compression energy of the water compressed under its own weight. In the example of a column of water held in a rigid cylindrical container, the width of the column may, for example, range from about 700mm to about 8m, in particular from about 746mm to about 7.62m.
The height of the column may, for example, be from about 60m to about 90m.
Other dimensions may be suitable, for example the diameter of the container may be about 50mm and up, and the height or head of the column may be about 10m and up. These dimensions may be varied, for example depending on the amount of power to be generated and/or depending on where the system is installed.
2) The stored elastic compression energy creates a volume reduction that can be suddenly let to expand to the normal volume, by allowing the water to push through the valve located at the bottom of the column. This creates a water mass in the form of a jet discharged from the valve. When the water is allowed to expand suddenly in this manner, it creates waves of `pressure drop';
starting at the valve and moving upwards, layer by layer, to the top of the column.
When the pressure drop wave reaches the top, the pressure of the water has been released through the valve. To limit the water loss when at a low pressure, the valve has to close fast, for example at the moment when the lowest or near lowest pressure in the column is reached (closing of the valve may not be exactly at the lowest pressure, for example due to response time of the control system). The amount of water discharged in each water jet may be dependent on the dimensions of the water column and the open/close speed of the valve. For example, a jet of water may discharge from about 1.2L to about 3.6L of water over a duration of about 1/20 to about 1/10 of a second.
3) When the valve closes, the pressure in the column begins to rise due to the gravity and water hammer effect creating a downward over pressure, due to the closing of the valve. The over pressure is higher than the static pressure when the valve is open.
4) When the overpressure reaches the peak or near peak, the valve is opened again (opening of the valve may not be exactly at the peak of the overpressure, for example due to response time of the control system), creating a stronger jet of water than the one developed by the static pressure in the column. The rhythmic open/close of the valve releases an ongoing series of intermittent jets.
5) The overpressure of the gravity and water hammer may help to increase the stored elastic compression energy.
6) The mass of the intermittent water jet expelled through the opening valve, by the force of weight, and the expansion, caused by the discharge of stored elastic compression energy, gains a generally higher velocity than the water that would have been expelled by the force of weight alone through the same opening. The higher velocity of the water jets also tends to be created in a shorter time.
Like some phenomena related to elasticity, the element of time may cause reaction changes. There may be challenges in analyzing water's elastic reaction due to changes from one time frame to another. By addressing the time element when studying water power, it was discovered that time is a factor for the conversion of elastic compression energy into kinetic energy, and from kinetic energy into power.
When considering the force experienced by the water in the column, it was found that the acceleration due to gravity, g, and the weight of the body, mg, does not disappear; it acts as a compression force, C. The would-be kinetic energy is transformed into stored elastic energy, K, of deformation, or compression in this case, in the order of. K = mC2 / 2e, where e is the bulk modulus of elasticity for water. This energy storage may be a result of a reduction of volume which is a temporary state in the disclosed system. When the water is free to move by the fast opening of the valve, the stored elastic energy becomes kinetic energy and is joined by the energy of the down moving force of the weight from the water exiting the container. The total kinetic energy of the jet of water is: Ejet = Ek + K = mgh + mC2 / 2e The overpressure of the water hammer increases the stored elastic energy of compression and converts it to kinetic energy so that it increases the velocity of the jet of water well above that of falling weight.
Because the system may be used in numerous situations and in different layouts, certain criteria may be taken into consideration for better efficiency and/or power output.
A) The location of the SFJV - The SFJV may be placed at the bottom of the water column, at the center or on one side, vertically or horizontally.
B) Shape of the bottom of column - The column of the column may have different shapes to control and/or improve water flow (e.g., hemispherical, conical, etc.).
C) Valve open time and moment of maximum pressure - The moment the pressure waves of the water hammer reaches the maximum pressure at the bottom of the column of water, the pressure at the top of the column is converted into kinetic energy moving the water upward.
This movement may continue for a fixed time, such as approximately 0.046 seconds in some examples, until the pressure waves moving downwards reach the bottom of the column and change the kinetic energy of the upward movement into pressure. This time may be determined in order to know the time to open the valve to release the pressure before a negative water hammer effect. This time may be dependent on the dimensions of the water column, such as the height and/or cross-sectional area. This timing may be taken into account in a feedback controller for the valve.
In conclusion, to reduce the amount of water used in the system and still maintain the power output of the generating system, the kinetic energy of the moving water may be improved in at least one of the following three ways:
1) The velocity, v, of the moving water may be increased;
2) The time in which the higher velocity is attained may be reduced;
A) The location of the SFJV - The SFJV may be placed at the bottom of the water column, at the center or on one side, vertically or horizontally.
B) Shape of the bottom of column - The column of the column may have different shapes to control and/or improve water flow (e.g., hemispherical, conical, etc.).
C) Valve open time and moment of maximum pressure - The moment the pressure waves of the water hammer reaches the maximum pressure at the bottom of the column of water, the pressure at the top of the column is converted into kinetic energy moving the water upward.
This movement may continue for a fixed time, such as approximately 0.046 seconds in some examples, until the pressure waves moving downwards reach the bottom of the column and change the kinetic energy of the upward movement into pressure. This time may be determined in order to know the time to open the valve to release the pressure before a negative water hammer effect. This time may be dependent on the dimensions of the water column, such as the height and/or cross-sectional area. This timing may be taken into account in a feedback controller for the valve.
In conclusion, to reduce the amount of water used in the system and still maintain the power output of the generating system, the kinetic energy of the moving water may be improved in at least one of the following three ways:
1) The velocity, v, of the moving water may be increased;
2) The time in which the higher velocity is attained may be reduced;
3) The increased velocity and the reduced time which is attained may be sustainable.
A column of water in a stationary condition stores elastic compression energy under its own weight. With the aid of mathematical equations, it may be shown that the use of the stored elastic compression energy may achieve conditions for improvement over the standard continuous flow method of power generation. It was shown experimentally that:
a) The stored elastic energy may be converted into the kinetic energy of a water jet by letting the water expand rapidly at the base of the column;
b) The velocity of the jet of water through the valve may be higher than v = ugh and may be reached in a shorter time than v = gt;
and c) The stored elastic energy may be renewed with elastic waves at a speed close to that of the propagation of pressure moving up and down through the water. This happens so that the valve may open and close in short cycles for sustained power output.
Examples In an experimental setup, the water column was 30.7 meters high, contained in a steel penstock 742mm (or 30") in diameter. Within the steel penstock, the water is compressed by two forces - its own weight and water hammer. The testing included a single penstock. The SFJV was set to develop 9.5 water jets per second, with the energy of expansion developing in 0.045 seconds. The duration of time is equivalent to the duration of the over-pressure provided for by the pressure waves, commencing upon the closing of the SFJV up until the corresponding reverse pressure waves would commence lowering the increased pressure. The power due to expansion was successful in developing 3860 watts of hydropower while operating at 16.66 revolutions per seconds or 1000 RPM.
Figure 2 shows an example of the disclosed system having two water columns.
Figure 3 shows another example of the disclosed system having two rigid containers, each having a SFJV. In this system, the water jets from one of the SFJV
valves drive a triplex power water pump to help raise the water to the original high 5 level (e.g., with the aid of external power to drive the water return pump).
The volume of water raised is expected to be in excess of the water loss to drive the pump. The excess of water is directed to a twin pipe system to drive an electric generator. A
small fraction of the power output of the electric generator is used to drive an air compressor for SFJV operation and have an excess of power to be used outside the 10 system.
The system may use power from another power source including, for example, power from solar power, wind turbines, gas, diesel, natural gas or any other suitable means, and which may be off-peak or less expensive power, to help pump the water back to the original high level.
A column of water in a stationary condition stores elastic compression energy under its own weight. With the aid of mathematical equations, it may be shown that the use of the stored elastic compression energy may achieve conditions for improvement over the standard continuous flow method of power generation. It was shown experimentally that:
a) The stored elastic energy may be converted into the kinetic energy of a water jet by letting the water expand rapidly at the base of the column;
b) The velocity of the jet of water through the valve may be higher than v = ugh and may be reached in a shorter time than v = gt;
and c) The stored elastic energy may be renewed with elastic waves at a speed close to that of the propagation of pressure moving up and down through the water. This happens so that the valve may open and close in short cycles for sustained power output.
Examples In an experimental setup, the water column was 30.7 meters high, contained in a steel penstock 742mm (or 30") in diameter. Within the steel penstock, the water is compressed by two forces - its own weight and water hammer. The testing included a single penstock. The SFJV was set to develop 9.5 water jets per second, with the energy of expansion developing in 0.045 seconds. The duration of time is equivalent to the duration of the over-pressure provided for by the pressure waves, commencing upon the closing of the SFJV up until the corresponding reverse pressure waves would commence lowering the increased pressure. The power due to expansion was successful in developing 3860 watts of hydropower while operating at 16.66 revolutions per seconds or 1000 RPM.
Figure 2 shows an example of the disclosed system having two water columns.
Figure 3 shows another example of the disclosed system having two rigid containers, each having a SFJV. In this system, the water jets from one of the SFJV
valves drive a triplex power water pump to help raise the water to the original high 5 level (e.g., with the aid of external power to drive the water return pump).
The volume of water raised is expected to be in excess of the water loss to drive the pump. The excess of water is directed to a twin pipe system to drive an electric generator. A
small fraction of the power output of the electric generator is used to drive an air compressor for SFJV operation and have an excess of power to be used outside the 10 system.
The system may use power from another power source including, for example, power from solar power, wind turbines, gas, diesel, natural gas or any other suitable means, and which may be off-peak or less expensive power, to help pump the water back to the original high level.
15 Figure 4 shows an example arrangement of the SFJVs on an example of the disclosed system with two water columns. As shown, the SFJVs may be arranged to increase the efficiency in driving the turbine.
Figure 5 shows an example of the disclosed system having three rigid containers for the water columns. In this configuration, each column is provided with an upper water reservoir, and the upper water reservoirs are in communication with each other. The SFJV from each column may be directed at the blades of a single turbine and arranged for increase efficiency. Each column may have an isolation valve for shutting off water from that column. In this way, the system may also be used as a two-column or one-column system. There may also be a water pump for returning discharged water as described above, and a spill duct for collecting discharged water. In this example, each rigid container may have a diameter of about 609mm, and be made of steel.
In some examples, the system may include a housing for a valve and turbine.
An example suitable housing may include a pressured water input for receiving water from the rigid container, an orifice opening for the water, and a turbine placement and turbine shaft for connecting to a turbine. The housing may also include a cam shaft, cam motor and cam wheel.
Figure 6 shows an example of a valve suitable for use in the disclosed system, in some aspects. A description of a suitable valve is provided in Canadian Patent Application No. 2,363,221, the entirety of which is hereby incorporated by reference.
The valve may include a piston that fits in an opening in the rigid container, which seals the opening when the piston is closed. In the example shown, the valve includes a valve body A in which a plunger B is driven by a piston C. The distal end of the plunger fits in an opening in the jet nozzle D. The valve may further include a plunger bushing E and a piston housing cover F. In the example shown, the valve communicates with the rigid container via a water supply port al, and may be driven by pneumatic power (e.g., provided through pneumatic ports a5). An optional nozzle reducer d4 is also shown. The valve may also include seals (e.g., as indicated at el, cl and f2). Other arrangements may be suitable.
Although certain configurations are indicated in this example, these are for the purpose of illustration only and are not intended to be limiting. In designing a suitable valve for use in the disclosed system, factors for consideration may include:
wear and tear due to rapid repeated open/close cycles; mass of the valve piston;
precise timing;
leakage; and durability. To address wear and tear, and to help increase the durability of the valve, an elastic member, such as a spring, may be included with the piston to provide the valve with a soft close such that the piston does not collide with the opening with excessive force when closing. Decreasing the mass of the piston and/or plunger may be useful in increasing the speed of the valve, and to address this, light-weight materials and/or a hollow core design may be used for the piston and/or plunger. Precise timing of the valve may be provided by using a cam-driven system.
Leakage may be decreased by using high quality seals, which may be replaceable, at the opening. In some examples, the valve may be designed to provide at least trillion open/close cycles over a life span of about 20 years. For example, the valve and the valve housing may be configured based on any conventional design, provided the valve is capable of high-speed opening and closing (e.g., on the order of milliseconds) and has a relatively long life for repeated rapid open/close cycles.
Figure 7 shows an example of a turbine suitable for use in an example of the disclosed system, in some aspects. The dimensions, number of blades, spacing of blades, orientation of blades, and other similar variables may be modified to increase efficiency of the turbine. Although the present disclosure describes the use of water, other fluids may be suitable for power generation using the disclosed system and method.
In some examples, the timing of the opening and closing of the valve may be controlled using a feedback loop, for example a proportional-integral-derivative (PID) controller, for example based on the power load feedback from the turbine generator and/or based on the pressure in the water column (e.g., as described above).
Opening and closing of the valve may be controlled by electrical or mechanical means.
For example, opening and closing of the valve may be controlled on the order of milliseconds. In some examples, a PID controller may receive feedback from the generator (e.g., using conventional feedback devices) and dynamically change the timing for opening and closing of the valve in response. This may help ensure that the generator is at a relatively stable or constant revolutions per minute (RPM) value, which in turn helps to ensure that the frequency of the generated power is relatively constant. This may be similar to conventional feedback control, such as Pelton turbine systems in which PID controlled governors maintain a constant RPM for the generator.
Another feedback for controlling the valve may be based on the pressure sensed in the water column (e.g., by a conventional pressure sensor or pressure transducer located, for example, at the bottom or near bottom of the rigid water container, near the valve or inside the valve body). At lowest or near lowest water pressure, the valve may be controlled to close, and at peak or near peak pressure, the valve may be controlled to open. The generator load feedback and/or the pressure feedback may be synchronized at the PID controller (e.g., by a processor that controls the PID controller) in order to control the valve.
Figure 5 shows an example of the disclosed system having three rigid containers for the water columns. In this configuration, each column is provided with an upper water reservoir, and the upper water reservoirs are in communication with each other. The SFJV from each column may be directed at the blades of a single turbine and arranged for increase efficiency. Each column may have an isolation valve for shutting off water from that column. In this way, the system may also be used as a two-column or one-column system. There may also be a water pump for returning discharged water as described above, and a spill duct for collecting discharged water. In this example, each rigid container may have a diameter of about 609mm, and be made of steel.
In some examples, the system may include a housing for a valve and turbine.
An example suitable housing may include a pressured water input for receiving water from the rigid container, an orifice opening for the water, and a turbine placement and turbine shaft for connecting to a turbine. The housing may also include a cam shaft, cam motor and cam wheel.
Figure 6 shows an example of a valve suitable for use in the disclosed system, in some aspects. A description of a suitable valve is provided in Canadian Patent Application No. 2,363,221, the entirety of which is hereby incorporated by reference.
The valve may include a piston that fits in an opening in the rigid container, which seals the opening when the piston is closed. In the example shown, the valve includes a valve body A in which a plunger B is driven by a piston C. The distal end of the plunger fits in an opening in the jet nozzle D. The valve may further include a plunger bushing E and a piston housing cover F. In the example shown, the valve communicates with the rigid container via a water supply port al, and may be driven by pneumatic power (e.g., provided through pneumatic ports a5). An optional nozzle reducer d4 is also shown. The valve may also include seals (e.g., as indicated at el, cl and f2). Other arrangements may be suitable.
Although certain configurations are indicated in this example, these are for the purpose of illustration only and are not intended to be limiting. In designing a suitable valve for use in the disclosed system, factors for consideration may include:
wear and tear due to rapid repeated open/close cycles; mass of the valve piston;
precise timing;
leakage; and durability. To address wear and tear, and to help increase the durability of the valve, an elastic member, such as a spring, may be included with the piston to provide the valve with a soft close such that the piston does not collide with the opening with excessive force when closing. Decreasing the mass of the piston and/or plunger may be useful in increasing the speed of the valve, and to address this, light-weight materials and/or a hollow core design may be used for the piston and/or plunger. Precise timing of the valve may be provided by using a cam-driven system.
Leakage may be decreased by using high quality seals, which may be replaceable, at the opening. In some examples, the valve may be designed to provide at least trillion open/close cycles over a life span of about 20 years. For example, the valve and the valve housing may be configured based on any conventional design, provided the valve is capable of high-speed opening and closing (e.g., on the order of milliseconds) and has a relatively long life for repeated rapid open/close cycles.
Figure 7 shows an example of a turbine suitable for use in an example of the disclosed system, in some aspects. The dimensions, number of blades, spacing of blades, orientation of blades, and other similar variables may be modified to increase efficiency of the turbine. Although the present disclosure describes the use of water, other fluids may be suitable for power generation using the disclosed system and method.
In some examples, the timing of the opening and closing of the valve may be controlled using a feedback loop, for example a proportional-integral-derivative (PID) controller, for example based on the power load feedback from the turbine generator and/or based on the pressure in the water column (e.g., as described above).
Opening and closing of the valve may be controlled by electrical or mechanical means.
For example, opening and closing of the valve may be controlled on the order of milliseconds. In some examples, a PID controller may receive feedback from the generator (e.g., using conventional feedback devices) and dynamically change the timing for opening and closing of the valve in response. This may help ensure that the generator is at a relatively stable or constant revolutions per minute (RPM) value, which in turn helps to ensure that the frequency of the generated power is relatively constant. This may be similar to conventional feedback control, such as Pelton turbine systems in which PID controlled governors maintain a constant RPM for the generator.
Another feedback for controlling the valve may be based on the pressure sensed in the water column (e.g., by a conventional pressure sensor or pressure transducer located, for example, at the bottom or near bottom of the rigid water container, near the valve or inside the valve body). At lowest or near lowest water pressure, the valve may be controlled to close, and at peak or near peak pressure, the valve may be controlled to open. The generator load feedback and/or the pressure feedback may be synchronized at the PID controller (e.g., by a processor that controls the PID controller) in order to control the valve.
In example systems having a water return pump, power load feedback from the generator may also be used to control when to pump water to replenish the water column. For example, during low power demand, the water return pump may be powered by the generator to pump water back into the system, which would also help to maintain a relatively constant load on the generator.
Figure 8 is a table showing test results of an example prototype system using the example valve of Figure 6, compared to a conventional continuous flow system (sample 13). In this example, the valve had a nozzle of about 15mm the system had a head (i.e., water column height) of about 20.1m, with a water volume of about 5-6 m3.
As shown, the example valve was controlled to open/close for periods ranging from about 30 to about 80 ms, with each valve opening releasing a water jet having a volume in the range of about 0.000110 to about 0.000140 m3 at an average velocity in the range of about 15 to about 20 m/s. This resulted in jet energy in the range of about to about 25 Nm and jet power in the range of about 350 to about 650 W. The 15 results of these tests indicated that the example prototype system was able to provide jet velocity about 20% higher than water velocity in the conventional continuous flow system and therefore more power generated using the same water consumption.
Although a range of about 30 to about 80 ms is shown for opening/closing of the valve, other timing may be used, for example anywhere in the range of about 10 to about 200 ms for each opening and closing. As described above, the higher velocity of water jets in the example system may be due to micro water hammer effects and water compression when the valve opens and closes in short bursts. Although fixed timing is shown for opening and closing of the valve, the opening and closing timing of the valve may be variable, for example as tuned by a feedback control loop (e.g., PID
controller) and may depend on the system size.
In some examples, the disclosed system may be retrofitted to existing water turbine systems (i.e., those using continuous flow to drive turbines) to help improve the efficiency of energy conversion. This may allow more power than conventional systems to be delivered with the same water consumption as conventional systems.
Figure 8 is a table showing test results of an example prototype system using the example valve of Figure 6, compared to a conventional continuous flow system (sample 13). In this example, the valve had a nozzle of about 15mm the system had a head (i.e., water column height) of about 20.1m, with a water volume of about 5-6 m3.
As shown, the example valve was controlled to open/close for periods ranging from about 30 to about 80 ms, with each valve opening releasing a water jet having a volume in the range of about 0.000110 to about 0.000140 m3 at an average velocity in the range of about 15 to about 20 m/s. This resulted in jet energy in the range of about to about 25 Nm and jet power in the range of about 350 to about 650 W. The 15 results of these tests indicated that the example prototype system was able to provide jet velocity about 20% higher than water velocity in the conventional continuous flow system and therefore more power generated using the same water consumption.
Although a range of about 30 to about 80 ms is shown for opening/closing of the valve, other timing may be used, for example anywhere in the range of about 10 to about 200 ms for each opening and closing. As described above, the higher velocity of water jets in the example system may be due to micro water hammer effects and water compression when the valve opens and closes in short bursts. Although fixed timing is shown for opening and closing of the valve, the opening and closing timing of the valve may be variable, for example as tuned by a feedback control loop (e.g., PID
controller) and may depend on the system size.
In some examples, the disclosed system may be retrofitted to existing water turbine systems (i.e., those using continuous flow to drive turbines) to help improve the efficiency of energy conversion. This may allow more power than conventional systems to be delivered with the same water consumption as conventional systems.
Although the present disclosure makes reference to examples and theories of operation, these are for the purpose of illustration only and are not intended to be limiting. A person skilled in the art would understand that variations and modifications, based on technologies both current and yet to be developed, may be possible within the scope of this disclosure. All references mentioned are hereby incorporated by reference in their entirety.
Claims (11)
1. A system for discharging water to a turbine to generate power, the system comprising:
a rigid container for containing contain a water column having a height sufficient to cause elastic compression of water in the water column and to accommodate propagation of compression waves in the water column;
a valve attached to the rigid container for intermittently discharging water at a lower end of the rigid container, the valve having an open/close cycle with a time duration in the range of about 10 to about 200 milliseconds, to facilitate generation of compression waves in the water column, wherein opening and closing of the valve is dynamically controlled by a feedback controller; and a turbine positioned adjacent to the valve, the valve being directed to periodically discharge water to drive the turbine.
a rigid container for containing contain a water column having a height sufficient to cause elastic compression of water in the water column and to accommodate propagation of compression waves in the water column;
a valve attached to the rigid container for intermittently discharging water at a lower end of the rigid container, the valve having an open/close cycle with a time duration in the range of about 10 to about 200 milliseconds, to facilitate generation of compression waves in the water column, wherein opening and closing of the valve is dynamically controlled by a feedback controller; and a turbine positioned adjacent to the valve, the valve being directed to periodically discharge water to drive the turbine.
2. The system of claim 1 further comprising a water pump for pumping discharged water into the rigid container to replenish the water column.
3. The system of claim 2 configured to receive power from an external power source for driving the water pump.
4. The system of any one of claims 1 to 3 configured to receive water from a flowing water source for replenishing the water column.
5. The system of any one of claims 1 to 4 wherein there are two or more rigid containers, each having a respective valve, the valves being directed at one or more turbines for driving the one or more turbines.
6. The system of any one of claims 1 to 5 wherein the valve comprises:
a plunger adapted to fit in an opening in the container, the opening being sealed when the plunger is in a closed position and opened when the plunger is in an opened position; and a piston and/or linkage system for driving opening and closing of the plunger.
a plunger adapted to fit in an opening in the container, the opening being sealed when the plunger is in a closed position and opened when the plunger is in an opened position; and a piston and/or linkage system for driving opening and closing of the plunger.
7. The system of claim 6 wherein the valve comprises an elastic member to assist in driving opening and closing of the plunger.
8. The system of any one of claims 1 to 7 wherein the rigid container has a wide bowl around an opening operated by the valve.
9. The system of any one of claims 1 to 8 wherein dynamic control of the valve based on at least one of. power load feedback from the turbine and pressure feedback from the water column.
10. A method of discharging water to a turbine to generate power, the method comprising:
compressing a water column; and intermittently discharging water from the water column to drive a turbine for generating power, the water being discharged in a dynamically controlled cycle having a time duration of about 10 to about 200 milliseconds, to facilitate generation of compression waves in the water column;
wherein the water column has a height sufficient to cause elastic compression of water and to accommodate propagation of compression waves in the water column.
compressing a water column; and intermittently discharging water from the water column to drive a turbine for generating power, the water being discharged in a dynamically controlled cycle having a time duration of about 10 to about 200 milliseconds, to facilitate generation of compression waves in the water column;
wherein the water column has a height sufficient to cause elastic compression of water and to accommodate propagation of compression waves in the water column.
11. The method of claim 11 further comprising returning discharged water to the water column.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US17825009P | 2009-05-14 | 2009-05-14 | |
| US61/178,250 | 2009-05-14 | ||
| PCT/CA2010/000744 WO2010130054A1 (en) | 2009-05-14 | 2010-05-14 | System for discharging water to a turbine to generate power |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2761843A1 true CA2761843A1 (en) | 2010-11-18 |
Family
ID=43084583
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA2761843A Abandoned CA2761843A1 (en) | 2009-05-14 | 2010-05-14 | System for discharging water to a turbine to generate power |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA2761843A1 (en) |
| WO (1) | WO2010130054A1 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ITLE20110002A1 (en) * | 2011-02-21 | 2012-08-22 | Marco Paolo Fabrizio De | HYDROELECTRIC POWER PLANT WITH WAVE MOTORCYCLE WITH A / C PUMPS ANIMATED BY FLOATS AND NOZZLES OF DELIVERY WITH DIFFERENTIATED COLLECTION IN THE RAISED TANK |
| WO2013019656A2 (en) * | 2011-07-29 | 2013-02-07 | Saudi Arabian Oil Company | System for producing hydraulic transient energy |
| GB2545890A (en) * | 2015-11-27 | 2017-07-05 | Lynton Foxcroft Derek | Novel energy system |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04271247A (en) * | 1990-09-22 | 1992-09-28 | Kiyotatsu Fukai | Pumping-up power plant |
| EP0555144A1 (en) * | 1992-02-07 | 1993-08-11 | Gec Alsthom Sa | Pump station |
| CA2363221A1 (en) * | 2001-11-19 | 2003-05-19 | Nicolas Pataceano | Super fast jet valve |
| DE102004047290A1 (en) * | 2003-09-24 | 2005-05-04 | Karl Ludwig Holder | Method for operating power station and power station carrying out, operation with water power station circuit converting water pressure energy into electric one, with several heat exchangers |
| US20060267346A1 (en) * | 2005-05-27 | 2006-11-30 | Tien-Chuan Chen | Hydraulic power plant driven by gravity and buoyancy circulation |
-
2010
- 2010-05-14 CA CA2761843A patent/CA2761843A1/en not_active Abandoned
- 2010-05-14 WO PCT/CA2010/000744 patent/WO2010130054A1/en active Application Filing
Also Published As
| Publication number | Publication date |
|---|---|
| WO2010130054A1 (en) | 2010-11-18 |
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