WO2023091755A1

WO2023091755A1 - Multi-cylinder rotary crankshaft pump systems and methods for wave-powered water desalinization

Info

Publication number: WO2023091755A1
Application number: PCT/US2022/050580
Authority: WO
Inventors: Mohammad-Reza ALAM; Michael Lanam KELLY; Aeden Peter GASSER-BRENNAN; Etienne Robin DROZ; Jacob Ivan HENDRY
Original assignee: The Regents Of The University Of California
Priority date: 2021-11-19
Filing date: 2022-11-21
Publication date: 2023-05-25

Abstract

Wave powered water desalination systems including a rotary crankshaft, a mooring spool coupled with the rotary crankshaft, at least four cylinders connected to the rotary crankshaft, wherein each of the at least four cylinders includes an inlet port for receiving salinized water and an outlet port for providing pressurized salinized water, and a reverse osmosis (RO) membrane component including a housing and a RO membrane, wherein a first side of the RO membrane component is connected to the outlet ports of the at least four cylinders. In use, with the mooring spool attached to an anchor on a seabed or to a surge flap, an oscillatory force of around 4-60 rpm is applied to the rotary crankshaft via the mooring spool, and pressurize salinized water at about 800 psi or greater is provided via the outlet ports to the RO membrane component from the at least four cylinders.

Description

MULTI-CYLINDER ROTARY CRANKSHAFT PUMP SYSTEMS AND METHODS FOR WAVE-POWERED WATER DESALINIZATION

CROSS-REFERENCES TO RELATED APPLICATIONS

[0001] This application claims priority to US Provisional Patent Application No. 63/281,483, filed November 19, 2021, which is incorporated by reference herein.

FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] This invention was made with government support under Grant Number 1752814 awarded by the National Science Foundation. The government has certain rights in the invention.

BACKGROUND

[0003] The present disclosure provides wave powered desalination systems and methods, and in particular wave powered desalination systems and methods including a low speed, high pressure rotary pump.

[0004] Ocean wave-powered desalination systems for coastal disaster recovery (e.g. after a tsunami, coastal flooding, hurricane, etc.) are desirable as people in such disaster recovery situations usually rely on shipments of water or diesel fuel to produce drinking water because the grid and water infrastructure may be down or contaminated. Accordingly improved, efficient desalination systems useful to provide desalinated water for everyday use and/or consumption are needed.

SUMMARY

[0005] The systems and methods according to the present embodiments produce clean water for coastal communities in disaster recovery or permanent scenarios using renewable ocean wave energy and free seawater as input.

[0006] According to an embodiment, a wave powered water desalination systems includes a rotary crankshaft, a mooring spool coupled with the rotary crankshaft, and at least four cylinders connected to the rotary crankshaft, wherein each of the at least four cylinders includes an inlet port for receiving salinized water and an outlet port for providing pressurized salinized water. The system also includes a reverse osmosis (RO) membrane component including a housing and a RO membrane, wherein a first side of the RO membrane component is connected to the outlet ports of the at least four cylinders. In use, with the mooring spool attached to an anchor on a seabed or to a surge flap, an oscillatory force of around 4-60 rpm is applied to the rotary crankshaft via the mooring spool, and pressurize salinized water at about 800 psi or greater is provided via the outlet ports to the RO membrane component from the at least four cylinders. [0007] According to certain aspects, the at least four cylinders are arranged inline. According to certain aspects, the at least four cylinders are arranged in one of a v-configuration, a w- configuration, a staggered flat configuration or a radial configuration. According to certain aspects, the at least four cylinders are double acting cylinders, enabling salinized water to be provided to the RO membrane component from the sea or from the RO membrane component to the sea.

[0008] According to certain aspects, the system further includes an inflatable element configured to maintain the system at sea level. According to certain aspects, the system includes or is coupled with a surface-hinged attenuator.

[0009] According to certain aspects, the system further includes a hose element attached to a second side of the RO membrane component for providing desalinized water to a location remote from the system.

[0010] According to certain aspects, the system further includes a battery and/or a solar panel for storing and providing power to electrical components of the system including a controller and electronically controlled valves.

[0011] Reference to the remaining portions of the specification, including the drawings and claims, will realize other features and advantages of the present invention. Further features and advantages of the present invention, as well as the structure and operation of various embodiments of the present invention, are described in detail below with respect to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Embodiments will be described in conjunction with the appended drawings to illustrate and not to limit the embodiments, and in which:

[0013] Fig. 1 illustrates a wave powered desalination system including a multi-cylinder crankshaft pump operating as a single point mooring heaving wave energy converter (WEC), according to an embodiment.

[0014] Fig. 2 illustrates a wave powered desalination system including a multi-cylinder crankshaft pump coupled with a submerged pitching WEC, according to an embodiment.

[0015] Fig. 3 illustrates a multi-cylinder crankshaft pump coupled with a surface hinged attenuator, according to an embodiment.

[0016] Fig. 4 shows a side view of a water powered desalination system deployed in a salt water environment, according to an embodiment.

[0017] Fig. 5 shows a perspective view of the water powered desalination system, according to an embodiment.

[0018] Fig. 6 shows an example hydraulic circuit scheme and flow of water diagram for a water desalination system including a crankshaft pump, according to an embodiment.

[0019] Fig. 7 shows a cutout view from back of the crankshaft pump side of the absorber housing, according to an embodiment.

[0020] Fig. 8 is a picture of a physical prototype of a crankshaft pump according to an embodiment.

DETAILED DESCRIPTION

[0021] In an embodiment, a wave-powered desalination system uses a novel, multi-cylinder rotary crankshaft pump to convert oscillating forces or moments from a wave energy absorber into high pressure flow compatible with a reverse osmosis (RO) membrane for desalination. The multi-cylinder rotary crankshaft pump is advantageously capable of operating at low angular velocities, and includes double acting cylinders that can adjust the flow rate by turning either side of the cylinders “on/off’.

[0022] This new rotary pump is also unique in that it provides high pressure flow with the low speed input forces from ocean waves. Previously, no rotary pump existed that could produce the high pressures that RO desalination requires (e.g., -800 psi) at the low speeds of ocean waves (e.g., 4-25 rpm) or other low speed oscillatory forces (e.g., 4-60 rpm); all high pressure rotary pumps surveyed could only operate in the thousands of rpm reliably.

[0023] The rotary nature of the present pumps prevents the potential for end stop collisions, a common failure mode for linear conversion wave energy converters. The double acting cylinders used in the crankshaft pump both smooth the output flow over each rotation of the crankshaft and allow for “cylinder shutoff control”, which can be used to adjust the system for different wave conditions and anchor sizes. With this autonomous control strategy, both sides of each cylinder can be controlled to send its outlet flow through the RO membrane (on) or back to the ocean (off) using valves adjusted by a microcontroller based on sensor feedback and user settings. The pump flow may be further smoothed using an accumulator, and a pressure relief valve to prevent overpressure on the RO membrane. Leaving the RO membrane is permeate (clean) flow that can be transported to shore via a hose, and high pressure salty brine which can be directed to the backside of the cylinders to augment input torque for water production or back to the ocean directly. The multi-cylinder rotary crankshaft pump embodiments can advantageously be used with heaving point absorber wave energy converters (WEC), bottom-fixed pitching WECs, surface attenuator WECs, or any other WEC design that produces linear or rotary motion. In the heaving configuration, the rotary nature of the pump design allows the system to adjust to different locations, tides, and wave heights easily, as the rope on the spool driving the crankshaft can extend or retract to the length needed.

[0024] An embodiment may be anchored, e.g., attached to an anchor on the sea bed (e.g. sandbags, sandscrews, chainball common in ports, other anchors or heavy masses), and a coupled freshwater hose can be brought back to shore. The system converts the energy in ocean waves into mechanical and hydraulic energy, pressurizing sea water through a reverse osmosis (RO) membrane and sending fresh water back to shore that is indeed drinkable by World Health Organization (WHO) standards. Thus a primary utility is to provide drinking quality water. Depending on the anchor size, modeling for a design that can fit in the 1 m^A3 shipping container has shown it can produce an average of -1400 liters/day of drinkable water with 394 mg/L of Total Dissolved Solids (TDS) with 4 sandscrew anchors, or -600 liters/day at 385 mg/L TDS with the a chain ball anchor. The acceptable range for TDS from the WHO for drinking water is <1000 mg/L, and the range that has good taste is <500 mg/L. WHO recommends on average people need 15 L of water per day for basic needs, resulting in the system providing water for about 93 people and 40 people, respectively, in the two anchor cases above. This is all from a device that has a shipping volume of less than 1 m^A3 (1000 L), meaning on average the system produces the amount of water that could fill the shipping volume of it every ~0.6 days or -1.5 days, respectively. These are modeling results, and true values may change depending on location, month, anchor type, and any design changes.

[0025] Advantages of the present embodiments include the following:

• Relative to Water shipments: communities are not reliant on supply chain

• Relative to Diesel powered desalination: no emissions, which can affect health of local communities; no reliance on expensive diesel fuel and shipments.

• Relative to solar- or wind-powered desalination: for the same shipping size, these units produce less water per day than the present embodiment (solar/wind energy is less dense than wave energy); water can be produced at night without the need for extra batteries; water production is more stable (wind energy is faster changing and less predictable than wave energy); no space on land required.

• Relative to other wave-powered desalination designs that produce electricity onboard: Running power cables back to shore is more dangerous and there will be more regulatory hurdles to jump through for such designs; the overall process is less efficient when producing power for desalination as there are more conversion steps.

[0026] In an embodiment, the wave powered desalination system works as a single point mooring heaving wave energy converter (WEC) as shown in Fig. 1. This makes it easy to deploy, as just one mooring line needs to be attached to an anchor at the seabed. In an embodiment, the multi-cylinder crankshaft pump may be coupled with a submerged pitching WEC as shown in Fig. 2. In an embodiment, the multi -cylinder crankshaft pump may be coupled with a surface hinged attenuator as shown in Fig. 3.

[0027] In an embodiment, the system is designed for small scale use (e.g., <100 person water volume per day per device), fits in a small shipping container (e.g., lm^A3), and is mainly meant for temporary use in coastal disaster recovery scenarios. However this design can be scaled up for larger water production and more permanent use for coastal communities. Thus, the system could be scaled to larger markets, and the multi-cylinder rotary crankshaft pump can be applied to other types of wave energy converters (WEC) or rotary systems. In an embodiment, the pump includes 4 cylinders inline, but the cylinder orientation and number of cylinders could also change and the system would work just as well or better with other WEC systems. As more cylinders are added, the variability of flow over a single crankshaft rotation is decreased. The cylinder orientation can be adjusted to any shape, v-type, w-type, staggered flat, radial, etc. For a heaving WEC design, the multi -cylinder rotary crankshaft pump may only pump water with a single direction of rotation, but for other WEC designs like a bottom fixed pitching flap it could also pump water in both rotary directions.

[0028] Fig. 4 shows a side view of a water powered desalination system deployed in a salt water environment, according to an embodiment. Fig. 5 shows a perspective view of the water powered desalination system.

[0029] Fig. 6 shows an example hydraulic circuit scheme and flow of water diagram for a water desalination system including a crankshaft pump and valve components according to an embodiment. Different layouts of solenoid valves can allow for different settings of the “on” flow to the RO membrane, or “off’ flow back to the ocean, allowing for adaptation to different wave climates.

[0030] Fig. 7 shows a cutout view from back of the crankshaft pump side of the absorber housing, according to an embodiment. Fig. 8 is a picture of a physical prototype of a crankshaft pump according to an embodiment.

[0031] All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. [0032] The use of the terms “a” and “an” and “the” and “at least one” and similar referents in the context of describing the disclosed subject matter (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The use of the term “at least one” followed by a list of one or more items (for example, “at least one of A and B”) is to be construed to mean one item selected from the listed items (A or B) or any combination of two or more of the listed items (A and B), unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or example language (e.g., “such as”) provided herein, is intended merely to better illuminate the disclosed subject matter and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0033] Certain embodiments are described herein. Variations of those embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the embodiments to be practiced otherwise than as specifically described herein. Accordingly, this disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.

Claims

8 CLAIMS:

1. A wave powered water desalination system, comprising: a rotary crankshaft; a mooring spool coupled with the rotary crankshaft; at least four cylinders connected to the rotary crankshaft, wherein each of the at least four cylinders includes an inlet port for receiving salinized water and an outlet port for providing pressurized salinized water; and a reverse osmosis (RO) membrane component including a housing and a RO membrane, wherein a first side of the RO membrane component is connected to the outlet ports of the at least four cylinders; wherein during operation with the mooring spool attached to an anchor on a seabed or to a surge flap, an oscillatory force of around 4-60 rpm is applied to the rotary crankshaft via the mooring spool, and pressurize salinized water at about 800 psi or greater is provided via the outlet ports to the RO membrane component from the at least four cylinders.

2. The system of claim 1, wherein the at least four cylinders are arranged inline.

3. The system of claim 1, wherein the at least four cylinders are arranged in one of a v-configuration, a w-configuration, a staggered flat configuration or a radial configuration.

4. The system of claim 1, wherein the at least four cylinders are double acting cylinders, enabling salinized water to be provided to the RO membrane component from the sea or from the RO membrane component to the sea.

5. The system of claim 1, further including an inflatable element configured to maintain the system at sea level.

6. The system of claim 1, coupled with a surface-hinged attenuator.

7. The system of claim 1, further including a hose element attached to a second side of the RO membrane component for providing desalinized water to a location remote from the system. 9

8. The system of claim 1, further including a battery and/or a solar panel for storing and providing power to electrical components of the system including a controller and electronically controlled valves.