Embodiments relate generally to the field of electrical energy and power, and more specifically to Time of Day (TOD) shifting, energy storage, energy and/or voltage regulation, and energy wasting (dumping).
Many energy storage facilities enable TOD shifting. Among other benefits, TOD shifting realizes a gain from the arbitrage in price between peak hours and off peak or super off peak hours. The difference in pricing at different periods throughout the day is attributed, among other things, to an imbalance in supply and demand. As more renewable energy enters the market and the electrical energy capacity generated from these sources increases, the imbalance between the supply and demand of electrical energy also increases.
In addition, there are existing issues with electrical energy generation such as the inability to switch off energy output from facilities such as coal and combined cycle power plants. The new and unreliable and/or unstable renewable energy entering the market is increasing the supply and demand imbalance. This raises concerns about over capacity in addition to the known issue of under capacity led by growing demand. Thus, both overcapacity and under capacity of electrical energy remain as yet unsolved.
In one or more embodiments, an energy storage apparatus includes at least one storage unit, at least one charge power unit, at least one discharge power unit. Each charge unit has a power capacity that is N/efficiency higher than that of each discharge power unit. N is greater than unity, for example, significantly greater than unity (e.g., at least one order of magnitude). Efficiency is defined as the maximum quantity of energy that can be withdrawn for a given quantity stored of the energy storage apparatus. The charge unit is connected to receive power from one or more power sources, and the discharge power unit is connected to dispatch power to a power consumer.
In one or more embodiments, an energy storage apparatus includes at least one storage unit, at least one charge unit, at least one discharge power unit, and a storage dissipation component. Each charge unit has a power capacity that is N/efficiency higher than that of each discharge power unit. N can be significantly greater than unity (e.g., at least an order of magnitude). Efficiency is defined as the maximum quantity of energy that can be withdrawn for a given quantity stored of the energy storage apparatus with zero waste energy storage selected. The storage dissipation component selectively wastes stored energy, incoming energy, or withdrawn energy such that the total energy storage capacity or rate capacity of energy storage is increased. The charge unit is connected to receive power from one or more power sources, and the discharge power unit is connected to dispatch power to a power consumer.
In one or more embodiments, an energy storage apparatus can have at least three modes of operation. A first mode of operation can be a charge stage, in which the apparatus consumes and stores energy. A second mode of operation can be a discharge stage in which the apparatus dispatches energy that has been stored therein. A third mode of operation can be an idle stage in which the apparatus neither consumers nor dispatches energy. The period of time to fully charge the apparatus is shorter than the period of time to fully deplete the apparatus, and the total power capacity of the charge stage divided by the efficiency of the apparatus is substantially greater than the total power capacity of the discharging stage of the apparatus.
Objects and advantages of embodiments of the disclosed subject matter will become apparent from the following description when considered in conjunction with the accompanying drawings.
Embodiments will hereinafter be described with reference to the accompanying drawings, which have not necessarily been drawn to scale. Where applicable, some features may not be illustrated to assist in the illustration and description of underlying features. Throughout the figures, like reference numerals denote like elements. As used herein, various embodiments can mean one, some, or all embodiments.
In electrical energy markets, periods of over capacity on the grid can raise concerns. Over capacity of electrical energy can be met by Pumped Storage Hydroelectricity (PSH) facilities (or systems), which account for over 95% of energy storage in the United States. PSH may provide a viable solution for TOD shifting, obtaining the advantages of price arbitrage between different hours of the day. However, today's energy market may desire solutions that provide more than TOD shifting.
For example, the energy market may desire solutions that provide the possibility for asymmetrical electrical energy capacity to draw down electrical power from the electrical grid and/or electrical energy wasting (i.e., dumping).
The desire to asymmetrically draw down power and generate electrical energy may be a result of electrical energy regulation/stabilization desires. For example, the desire for electrical energy regulation may include a desire to draw down large amounts of electrical power during one period of time and a desire to generate a relatively smaller amount of electrical power during a second period of time. Thus, in one or more embodiments, components of an energy storage system may be constructed to provide a charging rate that is different than a discharge rate and be controlled to accept electrical energy from the grid that exceeds its storage capacity, e.g., by dumping the excess energy via a non-productive (i.e., non-electricity generating) process.
The desire for electrical energy wasting (i.e., dumping) may occur at times or locations where the electrical power that is desired to be drawn down from the electrical grid exceeds the draw down (or storage) capacity of an electrical energy storage facility. In such a case, there may be a desire to draw down electrical power from the electrical grid and to create additional storage capacity within the storage facility to further draw down electrical power from the grid. To create additional storage capacity, some of the energy stored by the storage facility can be discharged without generating undesired electrical energy during the discharge of the storage facility. Alternatively or additionally, the drawn down power from the electrical grid may be dumped without passing through the storage facility (i.e., by running a non-productive system).
Some embodiments include a PSH facility (or system) that may be charged and discharged. During a first period the PSH may draw down electrical energy (e.g., power) from the electrical grid and power a water pump or water pumps. This first period and process is referred to herein as the charging cycle, i.e., when electricity from the grid is used to store energy. The pump may pump water from a lower altitude water bank to a higher altitude water bank. During a second period of time, water from the higher altitude bank may flow down to the lower altitude bank. During the second period, the water may drive a water turbine and generate electrical energy. This second period and process is referred to herein as the discharging cycle, i.e., when stored energy is subsequently used.
In some embodiments, the PSH is an asymmetric PSH that is configured such that the electrical energy draw down capacity is larger (e.g., significantly larger, for example, at least an order of magnitude larger) than the electrical energy generation capacity. In other words, the charging capacity (e.g., rate of energy storage) may be greater than the discharge capacity (e.g., rate of stored energy use). This may be achieved by increasing the capacity of the charging cycle, for example, by assembling devices in such a way that will lead to an asymmetric charge-discharge facility. In one embodiment, the asymmetric PSH includes a first number of water pumps (e.g., two or more) that operate to pump water from a lower altitude bank to a higher altitude bank. During the discharge a second number of water turbines less than the first number of water pumps (e.g., when the number of water pumps is two, the number of water turbines may be one) is driven by the flow of water from the higher altitude water bank to the lower altitude water bank. This results in an asymmetric charge-discharge cycle in which the draw down capacity of electrical energy is larger than the electrical energy generation capacity. In some embodiments, the number and/or size/efficiency of water pump(s) exceed the number and/or size/efficiency of the water turbine(s) such that the draw down capacity of electrical energy of the asymmetric PSH is significantly larger (e.g., at least an order of magnitude larger) than the electrical energy generation capacity of the asymmetric PSH.
In some embodiments, the asymmetric PSH can waste (i.e., dump) electrical energy capacity such as, for example, excess electrical energy capacity. This may be achieved by flowing water down from the higher altitude bank to the lower altitude bank through a passage that bypasses the turbine. The bypass passage can have a valve that allows the water to flow down during periods in which high electrical energy capacity draw down is desired. The bypass passage may enable the PSH facility to draw down an excess amount of electrical energy capacity, by means of powering the pumps, and allowing the pumped water to flow back down through the bypass without generating electrical energy. Thus, excess electrical energy from the grid may be consumed by this non-productive process, i.e., by cycling water from the low altitude bank to the high altitude bank, and back down to the low altitude bank.
Some embodiments include a Compressed Air Energy Storage (CAES) facility (or system) that may be charged and discharged. During a first period, the CAES facility may draw down electrical energy from the electrical grid and power a compressor, or compressors (this period and process will be referred to as the charging cycle). The compressor may compress ambient air into a cavern. The compressed air may be stored in the cavern for usage at a later time when needed for electrical energy generation. During a second period of time, compressed air located in the cavern may be released through a turbine. During the release of the compressed air, the compressed air may drive the turbine to generate electrical energy (this period and process will be referred to as the discharging cycle).
In some embodiments, the CAES is an asymmetrical CAES that is configured such that draw down capacity is larger (e.g., significantly larger) than the electrical energy generation capacity. This may be achieved by increasing the capacity of the charging cycle, which may be done by assembling devices such as compressors and turbines in such a way that will lead to an asymmetric charge-discharge facility. In one embodiment, the asymmetrical CAES includes two (or more) compressors that operate to compress ambient air into a cavern, and the compressed air may be stored in the cavern. During the discharge only one turbine (or more, but no more than the amount of compressors) is driven by the flow of compressed air from the cavern to the environment, resulting in asymmetric charge-discharge cycles in which the CAES's draw down capacity of electrical energy is larger than the CAES's electrical energy generation capacity. In some embodiments, the number and/or size/efficiency of compressor(s) exceed than the number and/or size/efficiency of the turbine(s) such that the draw down capacity of electrical energy of the asymmetrical CAES is significantly larger than the electrical energy generation capacity.
In some embodiments, the asymmetric CAES can waste (dump) electrical energy capacity. This may be achieved by releasing the compressed air in the cavern to the environment through a passage bypassing the turbine. The passage may have a valve that may allow the passage of compressed air to be released down during periods in which high electrical energy capacity draw down is desired. The bypass passage may enable the CAES to draw down an excess amount of electrical energy capacity by means of powering the compressors and releasing to the environment the now compressed air through the pass way without generating electrical energy. Thus, electrical energy may be consumed (i.e., drawn down) and air may be cycled from the environment to the cavern (compressed) and back to the environment, without generating electrical energy.
Some embodiments include a Liquid Air Energy Storage (LAES) facility (or system) that may be charged and discharged. During a first period the LAES may draw down electrical energy from the electrical grid and power a compressor or compressors (this period and process will be referred to as the charging cycle). The compressor(s) of the LAES may compress ambient air. In some embodiments, the compressed air is further processed such that the compressed air may be transformed to liquid air that may be stored. Processing the air may involve devices such as compressor(s) that may compress the air. When the air is compressed the temperature of the air may increase. This increased temperature of the air may be extracted from the air and stored in a high temperature thermal energy storage unit. Thus, during the charging cycle both low temperature liquid air can be generated and stored and high temperature thermal energy can be generated and stored. During a second period, liquid air may be pumped through the thermal energy storage unit. The liquid air may exchange low temperature for high temperature from the storage unit. The liquid air may expand and be directed to drive a turbine, thus generating electrical energy (this period and process will be referred to as the discharging cycle).
In some embodiments, the LAES is an asymmetric LAES that is configured such that the electrical energy draw down capacity is larger (e.g., significantly larger) than the electrical energy generation capacity. This may be achieved by increasing the capacity of the charging cycle by, for example, assembling and/or configuring devices such as, for example, one or more compressor(s) and turbine(s) to provide an asymmetric charge-discharge facility. In some embodiments, the asymmetric LAES includes two (or more) compressors that operate to compress ambient air. In some embodiments, the asymmetric LAES includes one or more compressors, one or more of which is a sized up compressor in relation to the smaller turbine. The compressed air may be processed, liquefied and stored in the LAES alongside high temperature thermal energy that may be stored in the high temperature thermal energy storage unit. During the discharge cycle, the liquid air may be pumped through the high temperature thermal energy storage unit and through a smaller sized (e.g., smaller capacity) turbine, resulting in asymmetric charge-discharge cycles in which the draw down capacity of electrical energy is larger than the electrical energy generation capacity. In some embodiments, the compressor(s) and turbine(s) are sized such that the draw down capacity of electrical energy of the asymmetric LAES is significantly larger than the electrical energy generation capacity.
Some embodiments include an asymmetric apparatus such as, for example, a LAES, a CAES, and/or a PHS that can include two or more sets of compressor trains to achieve the compression process. Each train can have one or more compressors. The trains can be connected such that an incoming air stream can be directed through any of one, two, or more trains in parallel or in series. For example, in some embodiments, the asymmetric apparatus can include two trains where the first train has the power capacity of 10 MW and the second train has the power capacity of 20 MW. In such embodiments, the air compression stage can utilize only the first train with the power of 10 MW, only the second train with the power of 20 MW or both trains with the total power of 30 MW.
In some embodiments, the asymmetric charge and discharge processes (i.e., cycles) may result in an efficiency loss due to, for example, the charge/discharge pressures ratio. By changing the compression power (by adding or removing compressors from the compression stage), the pressure of the charge cycle may not be optimal in regard to the pressure of the expansion stage, or it may change the charge to discharge pressure ratio. In some embodiments, an asymmetric LAES comprises different conduits of the working fluid or air stream may have different sizing. In such embodiments, different sizing of conduits at various stages of the LAES may control the charge or discharge pressure in such a way that may result in a desirable charge to discharge ratio. By changing the conduits sizing a more optimal pressure may be achieved at the charge and/or discharge stages, which may decrease the efficiency loss related to the charge/discharge pressures ratio. In some embodiments, the changed conduits can be associated with the different compressors, or associated with one or more sections throughout the system, and/or two sets of conduits, or any other configuration which may result in the same desirable ratio. Changing the conduits can include, for example, changing the configurations, sizing, amount, etc. of the conduits differently as opposed to a similar storage system which may operate in a symmetrical mode of operation.
In some embodiments, the asymmetric charge and discharge processes may result in a less efficient heat exchange at one or more thermal storage units such as, for example, the high temperature thermal storage unit of a LAES. In some embodiments, due to the unequal mass flows of the charge and discharge processes, one of the streams may not exchange the maximum possible heat. In some embodiments, each of the thermal storage units of an asymmetric LAES comprises two or more storage tanks For indirect heat exchange with different charge and discharge mass flows, the thermal stores' heat transfer fluid can be pumped from one storage to the other at a different rate and/or the different air streams may be controlled to flow through the heat exchangers at different rates achieved by configuring the needed conduits and valves to allow such operations. In some embodiments, the asymmetric LAES includes a second set of conduits. For direct heat transfer with different charge and discharge mass flows, the air may be directed to one, two, or more of the thermal stores during one process/cycle and may be directed to a different combination of thermal stores during the other process/cycle. For example, in some embodiments, during the charging cycle which may constitute a larger flow mass into the different storage unit, the air stream direction enters the first storage tank, exits the first storage tank, and enters the second storage tank (and so on, as desired). In such embodiments, during the discharging cycle, the air stream would be directed to both (or more) storage tanks in parallel to meet a higher heat exchange efficiency. Valves can be placed on the conduits and/or storage tanks to allow control over the different air streams (i.e., the air stream of the charging cycle and/or discharging cycle). In some embodiments, configuration of the storage tanks may be configured from the charging cycle side and the valves can direct the charging cycle air stream through the two (or more) storage tanks in parallel. The discharging cycle air stream can be directed through one (or more, but not all) storage tanks during one period of the discharging cycle and through a different one (or more, but not all) storage tanks during a second period of the discharging cycle.
In some embodiments, an asymmetric LAES is configured to selectively waste (i.e., dump) electrical energy capacity. This can be achieved by the LAES by pumping the liquid air through the high temperature storage unit, extracting thermal energy from the storage unit, and releasing the now vaporized air back into the environment. Additionally or alternatively, liquid air can be used to cool down devices such as the compressor while it is operating. The liquid air can be passed through the LAES but not to drive a turbine, and not to generate electrical energy. Thus, electrical energy may be consumed (i.e., drawn down) and air may be cycled from the environment to the liquid storage tank and back to the environment, without generating electrical energy.
In some embodiments, an asymmetric LAES or CAES is configured to selectively waste (dump) electrical energy capacity. This can be achieved by directing the drawn down electricity to be used by heating elements that can be located at the apparatus's hot thermal storage. Such heating elements may then raise the temperature of the apparatus's hot thermal storage, which may increase the efficiency of the apparatus's discharge process while not charging or discharging the apparatus.
Some embodiments include an electrical storage (battery) facility (or apparatus, or system) that can be charged and discharged. During a first period the battery may draw down electrical energy from the electrical grid and store the electrical energy (this period and process will be referred to as the charging cycle). During a second period of time electrical energy stored in the battery may be conveyed back to the electrical grid (this period and process will be referred to as the discharging cycle).
In some embodiments, the electrical storage battery is an asymmetrical battery facility (or apparatus, or system) for which electrical energy draw down (i.e., charging/storage) capacity is larger (e.g., significantly larger) than the electrical energy generation capacity, and the asymmetry can be achieved by shifting the battery cells between a series configuration and a parallel configuration. For example, the electrical battery can be constructed from a plurality of electrical cells. During the charging cycle, the cells may be aligned in a parallel fashion, thus increasing the draw down capacity of the charging cycle. During the discharge mode, the cells will be aligned in a series fashion thus decreasing the capacity of the discharge.
In some embodiments, the asymmetrical drawn down and generation capacities of an asymmetrical battery can be achieved by increasing the capacity of the charging cycle. The capacity of the charging cycle can be increased by assembling an electrical energy storage unit (e.g., a battery) containing a plurality of smaller electrical cells, each containing a positive and a negative side (and each cell capable of being charged and discharged). During the charge cycle the cells may be configured to form a parallel circuit. The cell interconnections may be altered during the discharge cycle to be configured to form a series circuit. Thus, the charging cycle will draw down a larger capacity of electrical charge per unit time than the generation capacity during the discharge cycle.
Asymmetric PSH 100 can be configured to selectively waste (i.e., dump) electrical energy during a period of time when there may be an excess of electrical energy on the electrical grid or any other electrical source. The PSH 100 may pump water from the low altitude bank 104 upstream to the high altitude bank 102. Due to the need to draw down a large capacity of electrical energy, water may flow down from the high altitude bank 102 to the low altitude bank 104, through a bypass channel 112. The bypass channel may contain a valve 110 for selectively allowing water to enter the bypass channel 112 during desired times and preventing water from entering the bypass channel 112 during periods of time when there is no desire to waste (i.e., dump) energy.
A controller (not shown) can be connected to valve 110 to control operation of the valve to selectively waste (i.e., dump) electrical energy based on, for example, a detection or prediction of a demand for energy uptake from a grid, energy supplier, or other power source. The same controller, or one or more additional controllers (not shown), can be connected to turbines 106, 108 to control the operation of PSH 100 as discussed above.
Asymmetric CAES 20 can be configured to selectively waste (i.e., dump) electrical energy capacity. During times where there is a need for electrical energy waste, the CAES facility 20, may draw down electrical energy capacity and power one or more compressors 22A, 22B to compress air and trap the compressed air in cavern 24. Air that has been compressed into the cavern 24 may be released by a bypass channel 28 back to the environment. The bypass channel 28 may contain a valve 26, which can allow air to pass through the bypass channel during to waste/dump energy. Valve 26 can also prevent air from entering the bypass channel during periods where there is no desire to waste/dump energy.
A controller (not shown) can be connected to valve 26 to control operation of the valve to selectively waste (i.e., dump) electrical energy based on, for example, a detection or prediction of a demand for energy uptake from a grid, energy supplier, or other power source. The same controller or one or more additional controllers (not shown) can be connected to compressors 22A, 22B and/or cavern 24 and/or turbine to control the operation of CAES 20 as discussed above.
In some embodiments, LAES 30 comprises a plurality of compressors and turbines. In such embodiments, the aggregated total of the draw down capacity of the compressors is larger than the aggregated total of the generation capacity of the turbines, thereby providing an asymmetric LAES charge-discharge cycle. LAES 30 can include one or more controllers (not shown) to control the operation of LAES 30 as discussed above.
LAES 30B can include one or more controllers (not shown) to control operation of LAES 30B, as discussed above, including to control operation of the valve to selectively waste (i.e., dump) electrical energy based on, for example, a detection or prediction of a demand for energy uptake from a grid, energy supplier, or other power source.
The charge unit 604 can be connected to receive power from one or more power sources such as, for example, a non-dispatchable power resource 610 and (optionally) a dispatchable power resource 608. For example, the dispatchable power resource can be an electricity power generation system that can vary to accommodate changes in load. For example, the dispatchable power resource can be a fossil fuel power plant. In contrast, the non-dispatchable power resource cannot accommodate changes in load because it is based on availability of a particular electricity generating resource. For example, the non-dispatchable power resource can be a solar power plant or wind power plant.
The discharge power unit is connected to dispatch power to a power consumer 612. In some embodiments, energy storage apparatus 600 includes a controller (not shown) for controlling the operation of energy storage apparatus 600 during charging and discharging cycles, as discussed hereinabove. In some embodiments, energy storage apparatus 600 can control the rate of energy waste based on the detection and/or prediction of a demand for energy uptake from a grid, energy supplier, or other power source.
In one or more embodiments of the disclosed subject matter, non-transitory computer-readable storage media and a computer processing systems can be provided. In one or more embodiments of the disclosed subject matter, non-transitory computer-readable storage media can be embodied with a sequence of programmed instructions for controlling asymmetric energy storage systems and discharging, charging, and/or dumping therein, the sequence of programmed instructions embodied on the computer-readable storage medium causing the computer processing systems to perform one or more of the disclosed methods.
It will be appreciated that the modules, processes, systems, and devices described above can be implemented in hardware, hardware programmed by software, software instruction stored on a non-transitory computer readable medium or a combination of the above. For example, a method for controlling asymmetric energy storage systems and discharging, charging, and/or dumping therein can be implemented, for example, using a processor configured to execute a sequence of programmed instructions stored on a non-transitory computer readable medium. For example, the processor can include, but is not limited to, a personal computer or workstation or other such computing system that includes a processor, microprocessor, microcontroller device, or is comprised of control logic including integrated circuits such as, for example, an Application Specific Integrated Circuit (ASIC). The instructions can be compiled from source code instructions provided in accordance with a programming language such as Java, C++, C#.net or the like. The instructions can also comprise code and data objects provided in accordance with, for example, the Visual Basicâ„¢ language, LabVIEW, or another structured or object-oriented programming language. The sequence of programmed instructions and data associated therewith can be stored in a non-transitory computer-readable medium such as a computer memory or storage device which may be any suitable memory apparatus, such as, but not limited to read-only memory (ROM), programmable read-only memory (PROM), electrically erasable programmable read-only memory (EEPROM), random-access memory (RAM), flash memory, disk drive and the like.
Furthermore, the modules, processes, systems, and devices can be implemented as a single processor or as a distributed processor. Further, it should be appreciated that the steps mentioned herein may be performed on a single or distributed processor (single and/or multi-core). Also, the processes, modules, and sub-modules described in the various figures of and for embodiments herein may be distributed across multiple computers or systems or may be co-located in a single processor or system. Exemplary structural embodiment alternatives suitable for implementing the modules, sections, systems, means, or processes described herein are provided below.
The modules, processes, systems, and devices described above can be implemented as a programmed general purpose computer, an electronic device programmed with microcode, a hard-wired analog logic circuit, software stored on a computer-readable medium or signal, an optical computing device, a networked system of electronic and/or optical devices, a special purpose computing device, an integrated circuit device, a semiconductor chip, and a software module or object stored on a computer-readable medium or signal, for example.
Embodiments of the methods, processes, modules, devices, and systems (or their sub-components or modules), may be implemented on a general-purpose computer, a special-purpose computer, a programmed microprocessor or microcontroller and peripheral integrated circuit element, an ASIC or other integrated circuit, a digital signal processor, a hardwired electronic or logic circuit such as a discrete element circuit, a programmed logic circuit such as a programmable logic device (PLD), programmable logic array (PLA), field-programmable gate array (FPGA), programmable array logic (PAL) device, or the like. In general, any process capable of implementing the functions or steps described herein can be used to implement embodiments of the methods, systems, or computer program products (software program stored on a non-transitory computer readable medium).
Furthermore, embodiments of the disclosed methods, processes, modules, devices, systems, and computer program product may be readily implemented, fully or partially, in software using, for example, object or object-oriented software development environments that provide portable source code that can be used on a variety of computer platforms. Alternatively, embodiments of the disclosed methods, processes, modules, devices, systems, and computer program product can be implemented partially or fully in hardware using, for example, standard logic circuits or a very-large-scale integration (VLSI) design. Other hardware or software can be used to implement embodiments depending on the speed and/or efficiency requirements of the systems, the particular function, and/or particular software or hardware system, microprocessor, or microcomputer being utilized. Embodiments of the methods, processes, modules, devices, systems, and computer program product can be implemented in hardware and/or software using any known or later developed systems or structures, devices and/or software by those of ordinary skill in the applicable art from the function description provided herein and with a general basic knowledge of electricity generation, electricity storage systems, and/or computer programming arts.
Features of the disclosed embodiments may be combined, rearranged, omitted, etc., within the scope of the invention to produce additional embodiments. Furthermore, certain features may sometimes be used to advantage without a corresponding use of other features.
It is thus apparent that there is provided in accordance with the present disclosure, systems, devices, and methods for asymmetric dispatching. Many alternatives, modifications, and variations are enabled by the present disclosure. While specific embodiments have been shown and described in detail to illustrate the application of the principles of the present invention, it will be understood that the invention may be embodied otherwise without departing from such principles. Accordingly, Applicants intend to embrace all such alternatives, modifications, equivalents, and variations that are within the spirit and scope of the present invention.
The present application claims the benefit of U.S. Provisional Application No. 61/908,252, filed Nov. 25, 2013, which is hereby incorporated by reference herein in its entirety.
Number | Date | Country | |
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61908252 | Nov 2013 | US |