Method and apparatus for simultaneous energy-watr nexus powered by a hydraulic wind turbine

Abstract

Systems and assemblies for harvesting and converting mechanical energy from wind into both electrical energy and desalinated and / or purified water. Wind turbines equipped with variable displacement hydraulic pumps and / or motors capture mechanical power from wind and convert it directly into hydraulic power in the form of pressurized fluid which in turn drives hydraulic motors operationally connected to electrical generators and reverse osmosis or other water purification systems.

Description

METHOD AND APPARATUS FOR SIMULTANEOUS ENERGY-WATERNEXUS POWERED BY A HYDRAULIC WIND TURBINECROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is related to and claims priority to US Provisional Patent Application 63 / 618,978 filed on January 9, 2024 which is incorporated herein by reference.FIELD

[0002] The claimed technology relates generally to wind energy and more particularly to the conversion of wind energy into electricity and / or fresh water.BACKGROUND

[0003] Electricity generation and water desalination are two critical basic needs that generate a large portion of global CO2 emissions. Electricity generation represents 40% of the total CO2 emissions on the planet. Desalination processes generate around 4.4 million tons of CO2 per year due to the use of electricity generated by plants or electric generators that use fossil fuels. Currently 63% of global electricity generation comes from fossil fuels, with only 5.3% generated by wind energy. Water desalination consumes approximately 0.4% of the global electricity demand distributed by the grid. Given that 63% of global electricity is generated by using fossil fuels, both critical processes represent a significant portion of the global carbon footprint.

[0004] Coupling electricity and water desalination with renewable energy reduces the carbon footprint of providing resources for these basic needs. The integration ofrenewable energy into electricity generation and water desalination has been explored in the past. However, it has been done separately, with a very complex and expensive layout. The limitation of the availability of energy harvested from wind using regular wind turbines involves a complex electric array to convert electricity into mechanical power to run a reverse osmosis system at ground level. Previously, energy conversion had to reach the stage of electrification to finally use an electric motor to drive the high- pressure pump. Multiple stages of energy conversion bring losses in efficiency and more costs in terms of hardware. In the case of electricity generation, the need for large energy storage banks also increases the cost of the systems. Additionally, the current configurations of wind turbines with the gearbox and generator in the nacelle bring higher costs in installation and maintenance compared to other configurations like hydraulic wind turbines. The present novel technology and method herein address the need to find alternative energy sources and conversion to provide electricity and freshwater using clean energy.SUMMARY

[0005] In one aspect, a system for generating electricity and purifying water having a wind turbine having a rotor and a nacelle, a variable displacement hydraulic pump operationally connected to the wind turbine rotor, an electricity generating sub-assembly operationally connected to the variable displacement hydraulic pump, further comprising a first hydraulic motor hydraulically connected to the variable displacement hydraulic pump, a generator operationally connected to the first hydraulic motor, a water purification sub-assembly operationally connected to the variable displacement hydraulic pump, further comprising, a second hydraulic motor hydraulically connected to the variable displacement hydraulic pump, a reverse osmosis pump operationally connected to the second hydraulic motor, and a desalination module operationally connected to the reverse osmosis pump. Optionally, the wind turbine rotor is coupled shaft-to- shaft to the variable displacement hydraulic pump. In some examples the variable displacement hydraulic pump is disposed in the nacelle portion of the wind turbine. The wind turbine may be disposed on a tower and the electricity generating sub-assembly and the water purification sub-assembly disposed at the base of the tower. The desalination module may further comprise a housing , a feed water inlet, a brine outlet, a fresh water outlet, and a desalination membrane disposed within the housing between the brine outlet and freshwater outlet. An energy recovery subassembly may be operationally connected to the first brine outlet, a brine reservoir connected in fluidic communication with the energy recovery subassembly, and a recovery generator operationally connected to the energy recovery subassembly configured to extract energy from brine passing between the brine outlet and the brine reservoir. The system may further include a hydraulicaccumulator operationally connected to the variable displacement hydraulic pump to dampen fluctuations induced by the turbulent wind flow. Optionally, the first hydraulic motor and the second hydraulic motor are variable displacement motors.

[0006] In another aspect an energy generation and water desalination system is provided which includes a wind turbine having a rotor and a nacelle, a variable displacement hydraulic pump operationally disposed in the nacelle and operationally connected to the wind turbine rotor, an electrical generation unit hydraulically connected to the variable displacement hydraulic pump comprising a hydraulic motor and a generator, and a water desalination unit hydraulically connected to the variable displacement hydraulic pump comprising a hydraulic motor and a reverse osmosis module.

[0007] In yet another aspect an energy generation and water desalination system is shown which includes a wind turbine having a rotor and a nacelle, a variable displacement hydraulic pump operationally connected to the wind rotor and disposed in the nacelle, an energy generating sub-assembly having a first hydraulic motor hydraulically connected to the variable displacement hydraulic pump and an electrical generator operationally connected to the first hydraulic motor, a water desalination sub-assembly having a second hydraulic motor hydraulically connected to the variable displacement hydraulic pump, a reverse osmosis pump operationally connected to the second hydraulic motor, and a desalination module operationally connected to the reverse osmosis pump, where the variable displacement hydraulic pump generates pressurized hydraulic fluid from rotation of the wind turbine rotor, and where pressurized hydraulic fluid from the variable displacement hydraulic pump powers the first and second hydraulic motors. Optionally, the desalination module further comprises a housing, a feed water inlet, a first outlet, asecond outlet, and a desalination membrane disposed within the housing between the first outlet and second outlet, where the first outlet is a brine outlet fluidically connected to a brine storage tank, and where the second outlet is a permeate water outlet fluidically connected to a permeate water storage tank. The system may further include an energy recovery unit disposed between the first outlet and the brine storage tank. Optionally, the wind turbine rotor is coupled shaft-to-shaft to the variable displacement hydraulic pump. In some examples, the wind turbine is disposed on a tower and the electricity generating sub-assembly and the water purification sub-assembly are disposed at the base of the tower. In further examples, a second wind turbine having a rotor and a nacelle disposed on a second tower is provided where a second variable displacement hydraulic pump is operationally connected to the wind rotor and disposed in the nacelle of the second wind turbine, and where the second variable displacement hydraulic pump is hydraulically connected to the first hydraulic motor and the second hydraulic motor. Optionally, the first hydraulic motor and the second hydraulic motor are variable displacement motors. The system may further include a hydraulic accumulator operationally connected to the variable displacement hydraulic pump to dampen fluctuations induced by the turbulent wind flow. In some examples a variable gearbox disposed between the wind turbine rotor and the variable displacement hydraulic pump.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is a diagrammatic view of a hydraulic wind turbine system according to one example of the disclosed technology.

[0009] FIG. 2 is a schematic view of a hydraulic wind turbine system according to another example of the disclosed technology.

[0010] FIG. 3 is a diagrammatic view of a hydraulic wind turbine system according to yet another example of the disclosed technology.DESCRIPTION

[0012] For the purposes of promoting an understanding of the principles of the claimed technology and presenting its currently understood best mode of operation, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the claimed technology is thereby intended, with such alterations and further modifications in the illustrated device and such further applications of the principles of the claimed technology as illustrated therein being contemplated as would normally occur to one skilled in the art to which the claimed technology relates.

[0013] The present disclosure details a method and apparatus for generating electricity and fresh water simultaneously using wind turbines fitted with hydrostatic transmissions. The principle behind the energy conversion process is to extract mechanical power from the rotor and convert it into fluid power using a hydrostatic transmission. In one example the operation involves the use of hydraulic units with variable displacement to control the maximum power extraction by the rotor while maintaining a high-power coefficient. An accumulator is typically included in the high-pressure line to dampen fluctuations and produce smoother power generation. Use of an optional constant gear ratio adaptability allows for variable input with constant output power transmission. The combination of wind energy and hydrostatic transmission technology provides a unique approach to generating electricity and fresh water simultaneously, making it a promising solution for renewable energy and water scarcity challenges.

[0014] In one example the mechanical drivetrain of a typical wind turbine is replaced with a hydrostatic transmission. This replacement allows the levelized cost of electricityto be reduced by 3% to 19%. Tn another example, a modular system of hydraulic technology allows power extracted from wind to be used for both electricity and freshwater generation / purification. By using a hydraulic wind turbine to power electricity and water generation, the carbon footprint can be reduced, and the levelized cost of electricity can be lowered, making this technology more competitive.Additionally, by coupling the hydraulic motor of the hydrostatic transmission of the wind turbine to the high-pressure pump of the reverse osmosis system, the need for energy conversion into electricity to use an electric motor to drive the high-pressure pump is eliminated, along with the complex electric hardware required. This represents a reduction in the cost of the reverse osmosis process.

[0015] In another example of the disclosed method and apparatus the kinetic energy from the wind is converted by the rotor of the wind turbine into mechanical power. The rotor of the wind turbine is typically coupled shaft-to-shaft to the hydraulic pump located in the nacelle of the wind turbine. The hydraulic wind turbine converts mechanical power into fluidic power. Flow at high pressure goes to the hydraulic motors located at ground level. One hydraulic motor drives the electric generator, and the second hydraulic motor drives the high-pressure pump of the reverse osmosis desalination system. The high- power density allows for a compact system with a very efficient power-weight ratio, providing an additional advantage for offshore applications. Most of the system is at the surface level, improving structural stability and reducing installation and maintenance costs.

[0016] Optionally, the ratio of electrical production to fresh water production can be adjusted as desired. In one example the ratio may be adjusted to produce more electricalpower during the day when consumption is higher and more fresh water at night when electrical usage drops. In other examples, the ratio may be adjusted according to other factors and all or nearly all of the output of a particular turbine directed towards one or the other of electrical power and water purification as desired.

[0017] The disclosed systems and apparatuses may be configured such that the water purification / reverse osmosis system removes impurities / contaminants from water other than salt. For example, the water purification / reverse osmosis components may be configured to remove chemicals (such as thickeners) and / or proppants associated with fracking operations. In other examples the water purification / reverse osmosis components may be configured to remove / mediate groundwater contaminants specific to a particular location.

[0018] In an example of the disclosed invention kinetic energy from wind is converted into mechanical power by the rotor of the wind turbine. A hydraulic pump is disposed in the nacelle, although in other examples the pump may be disposed elsewhere such as at the base of the tower supporting the rotor. In one example the hydraulic pump is coupled shaft-to- shaft to the rotor of the wind turbine. The harvested kinetic energy from the wind is converted to mechanical power by the rotor and then is then converted into fluid power by the pump. A high pressure flow is sent to one or more hydraulic motors (typically located at ground level). The hydraulic power is then divided such that a first portion is sent to a hydraulic motor driving a generator, and a second portion is sent to a hydraulic motor driving a high-pressure pump of a water treatment system (e.g., a reverse osmosis or RO system).

[0019] In the present example the output of the hydrostatic transmission provides mechanical power to drive both systems which are located at ground level. In other examples, one or both of the electrical generation and water purification systems may be located either above or below ground level as desired. In still other examples one or both of the electrical generation and water purification systems may be centralized and / or shared by multiple turbines. For example, more than one turbine may provide pressurized water or a central or shared water purification system.

[0020] The disclosed technology couples a wind turbine rotor to a variable displacement pump which allows for the conversion of mechanical power into hydraulic power. The use of a variable displacement pump allows the disclosed system to be adapted according to wind speed conditions by changing the gear ratio. The generated fluid flow may be directed through a high-pressure transmission line. In the same line, a hydraulic accumulator is typically operationally connected to the system so as to dampen pressure fluctuations caused by torque fluctuations in the rotor. Such torque fluctuations may be caused by turbulence of the incident wind speed. The hydraulic power is divertible between two hydraulic motors, with one fraction generating electricity and the other fraction generating fresh water.

[0021] A variable hydraulic motor driving an electric generator converts fluid power into mechanical power which is then converted into electricity. In one example eliminating a frequency inverter from the system and using a generator with a predetermined number of poles, the power generated at a desired frequency (e.g., at 60 Hz for the case of the USA and most of the rest of the world, at 50 Hz for other places in Europe). Generatedpower may be used locally, stored for later use, and / or provided to a power grid for transmission.

[0022] A variable hydraulic motor driving a high-pressure reverse osmosis pump is controlled to follow the working cycle of the desalination process in one example. The desalination process is carried out by pumping feed water through a high-pressure pump and then through a water- selective membrane. The separation process occurs inside the membrane and produces permeated water, while brine water is generated as a byproduct. The brine water exits at high pressure, for which an energy regeneration process can be conducted by using an energy recovery device (ERD), such as axial piston units coupled in tandem to high-pressure pump to reduce the power requirement or coupled to an electric generator.

[0023] Reverse osmosis (RO) stands as a water purification method employing a semi- permeable membrane to separate water molecules from other substances. By exerting pressure to overcome osmotic pressure that typically leads to even distributions, RO effectively eliminates dissolved or suspended chemical species and biological substances, primarily bacteria. This process finds extensive application in industrial processes and the production of potable water. In the RO process, the solute is retained on the pressurized side of the membrane, allowing the purified solvent to pass through to the opposite side. The effectiveness of RO relies on the size differences among various molecules, with "selective" membranes rejecting larger molecules while allowing smaller ones, such as solvent molecules (e.g., water), to pass through. In other examples, RO or other filtration techniques may be adapted to remove other impurities to purify drinking water. Such systems may be adapted to impurities found in specific location.

[0024] In the reverse osmosis process, water undergoes purification by subjecting a solution to high pressure, compelling water to traverse a thin-film composite membrane (TFC or TFM). These semipermeable membranes are primarily manufactured for applications in water purification and desalination systems, with additional uses in chemical applications like batteries and fuel cells. The bulk flow of water passes through the selectively permeable membrane due to an osmotic pressure difference. This mechanism selectively allows certain particles, including water, to pass through while retaining solutes such as salt and other contaminants.

[0025] In one example TFC material serves as a molecular sieve fashioned in the form of a film from two or more layered materials. These membranes, commonly composed of polyamide, are chosen for their permeability to water and relative impermeability to various dissolved impurities, including salt ions and other small molecules that cannot be filtered in the reverse osmosis process.

[0026] A diagrammatic view of a hydraulic wind turbine system according to one example of the disclosed technology is shown in Fig. 1. In this particular example a wind turbine 22 having a variable displacement hydraulic pump 56 in its nacelle 24 is disposed on a support structure 26 such as a tower is shown. The turbine 22 has a drive shaft 58 operationally connected to the input shaft 60 of the hydraulic pump 56. Optionally, a gear box or other device may be disposed between the drive shaft and input shaft so as to allow a gearing up or down between the two shafts as desired. Fluid from a feed line 32 is pumped up the support structure 26 and into the hydraulic pump 56 where it is pressurized and returned via a high-pressure line 30. The exact height of the support structure 26 and length of the feed line 32 and high-pressure line 30 may vary as desired.Any suitable hydraulic fluid may be used in the systems and the nature of such hydraulic fluid may vary depending on location, season, and local weather conditions.

[0027] Pressurized fluid is brought by the high-pressure line 30 to a sub-system location 28. The exact size, location, and configuration of the sub-system location 28 may vary as desired. In this particular example the sub-system location 28 is shown as disposed at the base of the support structure 26. In other examples the sub-system location may be located at a distance from a particular wind turbine support structure such that more than one hydraulic wind turbine according to the disclosed invention provides pressurized hydraulic fluid thereto such as shown in Fig. 3. The hydraulic wind turbine system 120 shown in Fig. 3 includes two hydraulic wind turbines 122, 124 as described herein which are operationally connected via hydraulic fluid lines 132, 134 to a sub-system location 126 which is located at a distance from the wind turbines 122, 124. The sub-system location 126 includes an electrical sub system 128 as well as a water treatment subsystem 130 such as described herein.

[0028] In other examples the sub-system location may be further divided into an electrical sub-system location having one or more electrical generators and a water subsystem location having one or more water purification / filtration systems. In still other examples a storage system may be disposed between a particular hydraulic wind turbine and a sub-system location so as to allow for the storage of pressurized hydraulic fluid.

[0029] One or more hydraulic motors 34 is disposed in the sub-system location 28 operationally connected to an electrical generator 36. Pressurized fluid from the high- pressure line 30 drives the hydraulic motor 34 which in turn drives the electrical generator 36 to produce electricity. The produced electricity may exit the sub-systemlocation 28 via electrical transmission lines and / or may be used to provide power within the system 20.

[0030] One or more hydraulic motors 34 is disposed in the sub-system location 28 operationally connected to a high-pressure pump 42. Pressurized fluid from the high- pressure line 30 drives the hydraulic motor 42 which in turn drives the high pressure pump 42. The high-pressure pump 42 draws salt water / contaminated water from a feed water source 46 and provides pressurized water to a filtration / purification system 44. In this particular example the purification system 44 is a RO system, but other types of filtration / purification systems may also be used as desired. The water source 46 may be an open body of water (e.g., lake, stream, ocean, and the like), ground water or aquifer, or water stored in tanks or other holding systems. Permeated water 48 from the purification system 44 may be stored in a holding tank, discharged into an existing water system for further treatment, or otherwise distributed as desired. Brine / waste water 50 from the purification system 44 may be stored or otherwise suitable disposed of as desired. Optionally, an ERD 52 may extract energy from the still pressurized brine 50 prior to storage / disposal of the water. The ERD 52 may be operationally connected to a generator which produces electricity.

[0031] One example of a hydraulic system 62 for use in the disclosed hydraulic wind turbine systems is shown in Fig. 2. In this particular example, a wind turbine 64 is operationally connected to a speed sensor 66. A pressure transducer 68 and flow meter 70 are operationally connected to the output line of a variable displacement hydraulic pump 72. Fluid is provided to the variable displacement hydraulic pump 72 by a charge pump 74 in the low pressure feed line 114 which may also include a pressure reducingvalve 76 (PRV) and / or filter 78 as desired. A pressure transducer 80 may also be operationally connected to the feed line 114. Check valves 82, 84 may also be provided on the high 112 and low 114 pressure lines as desired. An additional PRV 86 may also be provided between the high 112 and low 114 pressure lines. The high-pressure line 112 may also include an accumulator 88 to smooth out variability in flow. The high-pressure line 112 is operationally connected to a variable displacement hydraulic motor 92 which is operationally connected to an electric generator 94. The high-pressure line 112 is also operationally connected to a variable displacement hydraulic motor 96 which is operationally connected to a high pressure pump 98 which draws feed water from a feed line which optionally includes a flow meter 100, pressure transducer 102, prefilter 110, and / or PRV 104. The high-pressure pump 98 pumps contaminated feed water into the RO system 106 where a membrane separates permeate water from brine water. Permeate water is then stores or used as desired while brine water is used to drive an ERD 108 and extract further energy from the brine water before it is stored or disposed of as desired.

[0032] While the claimed technology has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character. It is understood that the embodiments have been shown and described in the foregoing specification in satisfaction of the best mode and enablement requirements. It is understood that one of ordinary skill in the art could readily make a nigh-infinite number of insubstantial changes and modifications to the above-described embodiments and that it would be impractical to attempt to describe all such embodiment variations in the present specification. Accordingly, it is understood that all changes andmodifications that come within the spirit of the claimed technology are desired to be protected.

Claims

CLAIMSWhat is claimed is:

1. A system for generating electricity and purifying water, comprising: a wind turbine having a rotor; a variable displacement hydraulic pump operationally connected to the wind turbine rotor; an electricity generating sub-assembly operationally connected to the variable displacement hydraulic pump, further comprising: a first variable displacement hydraulic motor hydraulically connected to the variable displacement hydraulic pump; a generator operationally connected to the first variable displacement hydraulic motor; a water purification sub-assembly operationally connected to the variable displacement hydraulic pump, further comprising: a second variable displacement hydraulic motor hydraulically connected to the variable displacement hydraulic pump; a reverse osmosis pump operationally connected to the second variable displacement hydraulic motor; a desalination module operationally connected to the reverse osmosis pump.

2. The system of claim 1, wherein the wind turbine rotor is coupled shaft-to- shaft to the variable displacement hydraulic pump.

3. The system of claim 1, wherein the wind turbine further includes a nacelle portion and the variable displacement hydraulic pump is disposed in the nacelle portion.

4. The system of claim 1, wherein the wind turbine is disposed on a tower and the electricity generating sub-assembly and the water purification sub-assembly are disposed at the base of the tower.

5. The system of claim 1, wherein the desalination module further comprises a housing , a feed water inlet, a brine outlet, a fresh water outlet, and a desalination membrane disposed within the housing between the brine outlet and freshwater outlet.

6. The system of claim 5, further comprising an energy recovery subassembly operationally connected to the first brine outlet; a brine reservoir connected in fluidic communication with the energy recovery subassembly; a recovery generator operationally connected to the energy recovery subassembly configured to extract energy from brine passing between the brine outlet and the brine reservoir.

7. The system of claim 1 wherein a hydraulic accumulator is operationally connected to the variable displacement hydraulic pump to dampen fluctuations induced by the turbulent wind flow.

8. The system of claim 1, further comprising a second wind turbine having a rotor and a nacelle; a second variable displacement hydraulic pump operationally connected to the rotor and disposed in the nacelle of the second wind turbine; wherein the second variable displacement hydraulic pump is hydraulically connected to the first variable displacement hydraulic motor and the second variable displacement hydraulic motor.

9. An energy generation and water desalination system, comprising: a wind turbine having a rotor and a nacelle; a variable displacement hydraulic pump operationally disposed in the nacelle and operationally connected to the wind turbine rotor; an electrical generation unit hydraulically connected to the variable displacement hydraulic pump comprising a hydraulic motor and a generator; a water desalination unit hydraulically connected to the variable displacement hydraulic pump comprising a hydraulic motor and a RO module.

10. An energy generation and water desalination system, comprising: a wind turbine having a rotor and a nacelle; a variable displacement hydraulic pump operationally connected to the wind rotor and disposed in the nacelle;an energy generating sub-assembly having a first hydraulic motor hydraulically connected to the variable displacement hydraulic pump and an electrical generator operationally connected to the first hydraulic motor; and a water desalination sub-assembly having a second hydraulic motor hydraulically connected to the variable displacement hydraulic pump, a reverse osmosis pump operationally connected to the second hydraulic motor, and a desalination module operationally connected to the reverse osmosis pump; wherein the variable displacement hydraulic pump generates pressurized hydraulic fluid from rotation of the wind turbine rotor; wherein pressurized hydraulic fluid from the variable displacement hydraulic pump powers the first and second hydraulic motors.

11. The system of claim 10, wherein the desalination module further comprises a housing , a feed water inlet, a first outlet, a second outlet, and a desalination membrane disposed within the housing between the first outlet and second outlet; wherein the first outlet is a brine outlet fluidically connected to a brine storage tank; wherein the second outlet is a permeate water outlet fluidically connected to a permeate water storage tank.

12. The system of claim 11, further comprising an energy recovery unit disposed between the first outlet and the brine storage tank.

13. The system of claim 10, wherein the wind turbine rotor is coupled shaft- to-shaft to the variable displacement hydraulic pump.

14. The system of claim 10, wherein the wind turbine is disposed on a tower and the electricity generating sub-assembly and the water purification sub-assembly are disposed at the base of the tower.

15. The system of claim 14, further comprising a second wind turbine having a rotor and a nacelle disposed on a second tower; a second variable displacement hydraulic pump operationally connected to the wind rotor and disposed in the nacelle of the second wind turbine; wherein the second variable displacement hydraulic pump is hydraulically connected to the first hydraulic motor and the second hydraulic motor.

16. The system of claim 10 wherein the first hydraulic motor and the second hydraulic motor are variable displacement motors.

17. The system of claim 10 further comprising a high-pressure hydraulic line operationally connecting the variable displacement hydraulic pump to the first and second hydraulic motors; wherein a hydraulic accumulator is operationally connected to the high-pressure hydraulic line to dampen fluctuations induced by the turbulent wind flow.

18. The system of claim 10 further comprising a variable gearbox disposed between the wind turbine rotor and the variable displacement hydraulic pump.

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