Patent Application
20230271686
The present disclosure relates generally to deep-sea mining systems and more specifically to a dynamic buoyancy system implemented in a deep-sea mining system. The dynamic buoyancy system applies variable buoyancy conditions that allow the deep-sea mining system to descend, collect ore nodules from the seabed, and ascend without seabed contact to limit the environmental impact.
As the world transitions to green energy solutions, there is a growing demand to store energy in reusable batteries made from critical metals such as nickel, copper, and cobalt. Currently, there are fewer sources of these metals remaining on land and these land-based resources can be in challenging places and/or within sensitive ecosystems. Deep sea mining is an un-tapped source of critical metals in the form of ore nodules (e.g., polymetallic ferromanganese nodules) and has been the focus of the mining industry in recent years.
Technical difficulties associated with deep-sea mining include the ocean depths (e.g., 5 km to 6 km) and the extreme pressures (e.g., between 500 bar and 600 bar) at which the mining of the ore nodules occurs, and the techniques required to transport the mined ore up to the ocean surface. There are two systems that have been widely examined and determined feasible on a small scale: (i) seabed dredging collector systems that pump the ore to the surface as a slurry through vertical riser pipes, and (ii) mechanical lifting systems that use synthetic ropes. However, both systems suffer from reliability and scaling issues, and can cause irreparable damage to sensitive environments due to the disturbances caused on the seabed during the mining process.
Therefore, there is a need for more sustainable ways to harvest minerals from the sea floor whilst keeping the seabed ecosystem intact.
A dynamic buoyancy system implemented for deep-sea mining systems and methods for using the same are disclosed herein. According to some embodiments, the disclosed dynamic buoyancy system enables the deep-sea mining system to hover at a predetermined distance over the seabed during the entire mining process, which minimizes the environmental impact of the mining process. Further, the deep-sea mining system using the dynamic buoyancy system disclosed herein does not depend on dredging or slurry risers for the ore collection and transportation to the sea surface, and can be scaled and deployed as a fleet of vehicles with redundancy. According to some embodiments, the dynamic buoyancy system enables the deep-sea mining system to descend to the seabed, travel along the seabed without contact while collecting the ore nodules, and ascend to the surface to deliver its payload. The dynamic buoyancy system applies variable buoyancy techniques and employs large pressure vessels designed to work at the planned ocean depths as the deep-sea mining system descends, collects ore, and ascends without seabed contact and with minimum environmental harm.
The accompanying figures, which are included as part of the present specification, illustrate the presently preferred embodiments and together with the general description given above and the detailed description of the preferred embodiments given below serve to explain and teach the principles described herein.
According to some embodiments, UAV 130 is equipped with thrusters (not shown in
According to some embodiments, deep-sea mining system 100 uses underwater surveying and inspection systems to identify the position of the ore nodules 120 on the seabed and to determine whether marine life is anchored on the nodules. By way of example and not limitation, deep-sea mining system 100 may be configured to avoid collecting ore nodules having marine life anchored on them. Once the payload hoper 150 is full, the dynamic buoyancy system 160 enables the deep-sea mining system 100 to ascent to the sea surface and deliver its payload.
According to some embodiments, the components of deep-sea mining system 100 (e.g., dynamic buoyancy system 160, payload hopper 150, ore collection system 140, and UAV 130) operate in synergy. In some embodiments, these components may be either integrated in a housing or operated as detachable modules physically and communicatively connected to one another. According to some embodiments, dynamic buoyancy system 160, payload hopper 150, ore collection system 140, and UAV 130 are physically attached to one another during the collection/mining process, and at least the payload hopper 150 and the dynamic buoyancy system 160 can be physically attached to one another during the mining and ascending process. In some embodiments, the dynamic buoyancy system 160 can provide the necessary buoyancy to compensate for the collected ores during the mining process and the ascent of at least the payload hopper 150 or of the entire deep-sea mining system 100. In some embodiments, if the dynamic buoyancy system 160 and the payload hopper 150 ascent on their own to the ocean surface, UAV 130 may provide with its thrusters the necessary buoyancy to deep-sea mining system 100 until the dynamic buoyancy system 160 and the payload hopper 150 descend again from the sea surface to re-attach to the deep-sea mining system 100.
In some embodiments, deep-sea mining system 100 can include additional components, modules, and systems necessary for its operation. These additional components, modules, and systems are not shown in
Details of the dynamic buoyancy system 160 are shown in
Pressure vessel 200, as shown in
In some embodiments, primary pump 220 is a high-pressure, low-volume (HPLV) pump intended to pump the incompressible liquid from the pressure vessel 200 (e.g., via valve 290) at a depth corresponding to a surrounding sea water pressure of about 600 bars. In some embodiments, primary pump 220 can be a high-power output pump (e.g., with about 300 hp of output power) with a pump rate that can match the ore collection rate. By way of example and not limitation, the pump rate of primary pump 220 can be at least 4 liters/sec. By way of example and not limitation, primary pump 220 can be single or multi-stage pump.
The pumps described above can be powered by a rechargeable power source 240 which can be charged via charging port 240a when dynamic buoyancy system 160 in at the sea surface. According to one embodiments, power source 240 can be a 400 kWh rechargeable battery. By way of example and not limitation, power source 240 can be a Lithium Iron Phosphate (LiFePO4) battery. However, any suitable rechargeable battery may be used based on the desirable cycle durability and energy density requirements.
According to some embodiments, the deep-sea mining system 100 shown in
In referring to
According to some embodiments, dynamic buoyancy system 160 is further equipped with sensors (not shown in
In some embodiments, buoyancy foam 210 can provide static buoyancy to compensate for the mass of dynamic buoyancy system 160 so that the dynamic buoyancy system 160 itself is neutrally buoyant when deep-sea mining system 100 is at the target depth (e.g., at a depth between about 5 km and 6 km). By way of example and not limitation, buoyancy foam 210 can be a syntactic foam—e.g., hollow glass microspheres (microballoons) cast in resin. Adding buoyancy foam to the dynamic buoyancy system 160 increases the buoyancy. Neutral buoyancy can be achieved by adding enough buoyancy foam 210 so that the upward force due to the water displacement caused by buoyancy foam 210 and pressure vessel 200 compensates for the mass of the dynamic buoyancy system 160.
In other embodiments, the deep-sea mining system 100 can include a buoyancy system that features more than one (e.g., multiple) pressure vessels 200 as shown by way of example and not limitation in
By way of example, the deep-sea mining system 100, may be equipped with a buoyancy system having an array of 21 pressure vessels 200, each pressure vessel 200 forming a dynamic buoyancy sub-system 400 arranged in 3×7 array as shown in
With multiple dynamic buoyancy systems, as discussed above, the deep-sea mining system 100 can compensate for the uneven distribution of ore nodules in payload hoper 150. For example, uneven loading may occur when the ore nodules are not evenly distributed in payload hoper 150 (e.g., more ores may accumulate on one side of payload hoper 150). If a single dynamic buoyancy system was used in an uneven loading scenario, the thrusters of UAV 130 located on the heavy side would have to work continuously to keep deep-sea mining system 100 leveled. In contrast, and by using an array of dynamic buoyancy systems (e.g., an array of dynamic buoyancy systems 400 as discussed above), buoyancy can be adjusted by operating the dynamic buoyancy systems 400 located on the heavy side so that deep-sea mining system 100 remains leveled without the need for corrective action from the thrusters of UAV 130.
Another benefit of using multiple dynamic buoyancy systems is operational redundancy. For example, in the event that one of the dynamic buoyancy systems fails, another dynamic buoyancy system may be activated so that deep-sea mining system 100 can continue to operate without disruptions.
According to some embodiments, the dynamic buoyancy system (e.g., dynamic buoyancy system 160 or each of the dynamic buoyancy systems 400) responds to data communications form other modules and dynamically adjusts the buoyancy by pumping liquid in and out of its pressure vessel 200 to meet the motion objectives of deep-sea mining system 100. According to some embodiments, the dynamic buoyancy system can communicate with UAV 130, which can request a buoyancy rate adjustment based on the thrust vector requirements so that deep-sea mining system 100 maintains its distance from the seabed. The term “thrust vector” as used herein refers to the combined force acting on the deep-sea mining system 100 at any given moment and includes the vertical buoyancy forces applied by the one or more dynamic buoyancy systems and the horizontal and/or vertical forces applied by the thrusters of UAV 130. Additionally, the dynamic buoyancy system can communicate with the ore collection system 140, which, based on its perceived ore mass collection rate, can request that the buoyancy is adjusted to maintain deep-sea mining system 100 at a pre-determined distance from the seabed without the need to engage the thrusters from UAV 130. This limits the energy consumed by UAV 130. Further, the dynamic buoyancy system can communicate with mining ship 110 (e.g., via UAV 130 or via another module) to adjust the buoyancy so that the deep-sea mining system 100 can be parked at a given depth in case of adverse weather, repairs, or other reasons.
The operation of the dynamic buoyancy system 160 (and each of the dynamic buoyancy systems 400) under different buoyancy conditions is schematically shown and described in
According to some embodiments, the gas pressure inside pressure vessel 200 must be sufficient so that when the entire volume of liquid from pressure vessel 200 is pumped out, the gas pressure inside pressure vessel 200 is equal to or slightly below the atmospheric pressure (i.e., between about 14.6 psi and about 3.2 psi, with 14.6 psi being the atmospheric pressure) so that the primary pump 220 can remain operational underwater. In the event that the gas pressure inside pressure vessel 200 is not sufficient and pressure vessel 200 is “under vacuum” (e.g., the pressure of pressure vessel 200 is below 3.2 psi) while there is still liquid to be pumped out, the remaining liquid will start to evaporate and the liquid's vapor pressure can compromise the pump's ability to remove additional liquid from pressure vessel 200. In this “pressure vessel vacuum scenario,” dynamic buoyancy system 160 will fail to provide the necessary buoyancy to the deep-sea mining system 100.
The aforementioned “pressure vessel vacuum scenario” can be avoided by setting the initial volume and pressure of the gas in pressure vessel 200 such that when all the desired liquid is pumped out, the pressure of the gas, as approximated by the ideal gas law, is not below the pumpable limit of primary pump 220 (e.g., below about 3.2 psi). The gas pressure, along with the maximum internal operating pressure of pressure vessel 200, can determine the minimum volume of gas, and consequently, the maximum volume of liquid allowed in pressure vessel 200. Additional gas volume can be allocated (e.g., a larger pressure vessel 200 may be used) to lower the gas pressure and increase the maximum allowable liquid volume in pressure vessel 200 so that when the pressure vessel 200 is emptied of the liquid, the gas pressure is equal to or above the minimum pumpable limit of 3.2 psi—e.g., between about 14.6 psi and about 3.2 psi, as discussed above. Alternatively, additional static buoyancy may be provided by increasing the amount of buoyancy foam 210 in the dynamic buoyancy system 160.
In some embodiments, and while the buoyancy of deep-sea mining system 100 is on the surface, the pressure vessel 200 can be prepared with a volume of air that includes: (i) a minimum gas volume 300, (ii) a static buoyancy gas volume 310, and (iii) a gas volume reserved for the descent mass volume 320, as shown in
According to some embodiments, dynamic buoyancy system 160 is designed so that if the volume of the liquid present in pressure vessel 200 is equal to the neutral buoyancy level, the deep-sea mining system 100 can be neutrally buoyant. In the example of
When the descent is initiated (e.g., by data communication to the controller 230 shown in
As the deep-sea mining system 100 approaches the seabed, it is commanded to pump out enough liquid volume to gain neutral buoyancy, which removes the downward force and causes it to decelerate and stop close to the seabed. In other words, while the deep-sea mining system 100 is reaching its target depth (e.g., between 5 km and 6 km), primary pump 220 can bring the volume of the liquid to the neutral buoyancy level 300 so that the deep-sea mining system 100 becomes neutrally buoyant. This ensures that the deep-sea mining system 100 can stay at its target depth (e.g., at a predetermined distance from the seabed) with minimal effort and without heavily relying on the thrusters from UAV 130. According to some embodiments, the thrusters of UAV 130 shown in
At the target depth, the collection of ore nodules 120 may commence. During the collection process, the deep-sea mining system 100 travels horizontally (e.g., along the x-y plane shown in
According to some embodiments, the liquid's pump rate (which is based on the known density of the liquid) is proportional to the pump's pumping rate (which is proportional to the pump's rotational rate) and is matched to the collected (net in water) ore mass loading rate. In some embodiments, the mass loading rate is calculated by the ore collection system 140 shown in
According to some embodiments, any differences between the estimated and actual ore mass will result in a buoyancy error, which can be compensated immediately by the thrusters of UAV 130. As discussed above, operation of the thrusters in a response to a buoyancy error is fed forward to the dynamic buoyancy system 160 to adjust the pump rate of primary pump 220. According to some embodiments, during and upon completion of collection process, deep-sea mining system 100 remains neutrally buoyant.
Once the deep-sea mining system 100 reaches its maximum load capacity and it is time for it to ascend, dynamic buoyancy system 160 is requested (e.g., via data communications to controller 230) to pump out (e.g., with primary pump 220) a liquid volume equal to the ascend mass volume 350. This allows the deep-sea mining system 100 to achieve positive buoyancy and ascend with the ore payload at terminal velocity towards the sea surface. This is shown schematically by the “Ascending” stage E in
In some embodiments, when it is desirable to temporarily “park” the deep-sea mining system 100 either during the ascent or decent without long term energy use, data communications to controller 230 can command the dynamic buoyancy system 160 to pump in or out liquid (whatever the case may be) to achieve neutral buoyancy. The process can be reversed when the trip resumes.
It is to be appreciated that the dynamic buoyancy system described herein is not limited to deep-sea mining systems and can be implemented in any type of submersible vehicle that operates under autonomous, semi-autonomous, or manual control at any operating depth. Further, the dynamic buoyancy system described herein is not limited to submersible vehicles that carry payloads.
The operating principles described herein for the dynamic buoyancy system 160 are directly applicable to deep-sea mining systems equipped with multiple pressure vessels 200, like the dynamic buoyancy systems 400 shown in
The phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
The term “approximately”, the phrase “approximately equal to”, and other similar phrases, as used in the specification and the claims (e.g., “X has a value of approximately Y” or “X is approximately equal to Y”), should be understood to mean that one value (X) is within a predetermined range of another value (Y). The predetermined range may be plus or minus 20%, 10%, 5%, 3%, 1%, 0.1%, or less than 0.1%, unless otherwise indicated.
The indefinite articles “a” and “an,” as used in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.” The phrase “and/or,” as used in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and/or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to “A and/or B”, when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.
As used in the specification and in the claims, “or” should be understood to have the same meaning as “and/or” as defined above. For example, when separating items in a list, “or” or “and/or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.” “Consisting essentially of,” when used in the claims, shall have its ordinary meaning as used in the field of patent law.
As used in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and/or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.
The use of “including,” “comprising,” “having,” “containing,” “involving,” and variations thereof, is meant to encompass the items listed thereafter and additional items.
Use of ordinal terms such as “first,” “second,” “third,” etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed. Ordinal terms are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term), to distinguish the claim elements.
Having thus described several aspects of at least one embodiment of this invention, it is to be appreciated that various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description and drawings are by way of example only.
This application claims the benefit of U.S. Provisional Patent Application No. 63/314807, titled “METHOD AND APPARATUS FOR A DYNAMIC BUOYANCY SYSTEM FOR DEEP-SEA MINING,” which was filed on Feb. 28, 2022 and is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63314807 | Feb 2022 | US |
