US20060024543A1 - Fuel cell system with controller and smart cartridge - Google Patents

Abstract

Described herein is a portable storage device that stores a hydrogen fuel source. The storage device includes a bladder that contains the hydrogen fuel source and conforms to the volume of the hydrogen fuel source. A housing provides mechanical protection for the bladder. The storage device also includes a connector that interfaces with a mating connector to permit transfer of the fuel source between the bladder and a device that includes the mating connector. The device may be a portable electronics device such as a laptop computer. Refillable hydrogen fuel source storage devices and systems are also described. Hot swappable fuel storage systems described herein allow a portable hydrogen fuel source storage device to be removed from a fuel processor or electronics device it provides the hydrogen fuel source to, without shutting down the receiving device or without compromising hydrogen fuel source provision.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application claims priority under U.S.C. §120 from co-pending U.S. patent application Ser. No. 10/877,766, filed Jun. 25, 2004 and entitled, “PORTABLE FUEL CARTRIDGE FOR FUEL CELLS”, which is incorporated herein for all purposes and which claims priority under 35 U.S.C. §119(e) from: a) U.S. Provisional Patent Application No. 60/482,996 filed Jun. 27, 2003 and entitled “Fuel cell system startup procedure and self-heating apparatus”, which is incorporated by reference for all purposes; b) U.S. Provisional Patent Application No. 60/483,415 filed Jun. 27, 2003 and entitled “Refillable Smart Methanol Cartridge for Fuel Cells”, which is incorporated by reference for all purposes; and c) U.S. Provisional Patent Application No. 60/483,416 filed Jun. 27, 2003 and entitled “Fuel Preheat in Portable Electronics Powered by Fuel Cells”, which is incorporated by reference for all purposes.
BACKGROUND OF THE INVENTION
• The present invention relates to fuel cell technology. In particular, the invention relates to portable fuel cell storage devices that store a fuel source, allow transportation of the fuel source, and permit coupling to electronics devices including a fuel processor that converts the fuel source to hydrogen.
• A fuel cell electrochemically combines hydrogen and oxygen to produce electrical energy. The ambient air readily supplies oxygen. Hydrogen provision, however, calls for a working supply. Gaseous hydrogen has a low energy density that reduces its practicality as a portable fuel. Liquid hydrogen, which has a suitable energy density, must be stored at extremely low temperatures and high pressures, making storing and transporting liquid hydrogen burdensome.
• A reformed hydrogen supply processes a fuel source to produce hydrogen. The fuel source acts as a hydrogen carrier. Currently available hydrocarbon fuel sources include methanol, ethanol, gasoline, propane and natural gas. Liquid hydrocarbon fuel sources offer high energy densities and the ability to be readily stored and transported. A fuel processor reforms the hydrocarbon fuel source to produce hydrogen.
• To date, fuel cell evolution has concentrated on large-scale applications such as industrial size generators for electrical power back-up. Consumer electronics devices and other portable electrical power applications currently rely on lithium ion and similar battery technologies. Portable fuel source storage devices that service portable electronics such as laptop computers would be desirable but are not yet commercially available.
SUMMARY OF THE INVENTION
• The present invention relates to a portable storage device that stores a hydrogen fuel source. The storage device includes a bladder that contains the hydrogen fuel source and conforms to the volume of the hydrogen fuel source. A housing provides mechanical protection for the bladder. The storage device also includes a connector that interfaces with a mating connector to permit transfer of the fuel source between the bladder and a device that includes the mating connector. The device may be a portable electronics device such as a laptop computer. A digital, electrical or mechanical means of identifying and updating information relevant to usage of the storage device may also be employed.
• Refillable hydrogen fuel source storage devices are also provided. A hydrogen fuel source refiner includes the mating connector and fills the storage device with hydrogen fuel source.
• In a fuel cell system that receives the hydrogen fuel source from the storage device, a fuel processor may reform the hydrogen fuel source to produce hydrogen, and then provides the hydrogen to a fuel cell that generates electricity using the hydrogen.
• Hot swappable fuel storage systems described herein allow a portable hydrogen fuel source storage device to be removed from a fuel processor or electronics device it provides the hydrogen fuel source to, without shutting down the receiving device or without compromising hydrogen fuel source provision to the receiving device for a limited time. The hot swappable system comprises a reserve that provides the hydrogen fuel source to the receiving device. The reserve includes a volume that stores the hydrogen fuel source when the connector and mating connector are separated.
• In one aspect, the present invention relates to a storage device for storing a hydrogen fuel source. The storage device comprises a bladder that contains the hydrogen fuel source and conforms to the volume of the hydrogen fuel source in the bladder. The storage device also comprises a housing that provides mechanical protection for the bladder. The storage device further comprises a connector that interfaces with a mating connector to permit transfer of the fuel source between the bladder and a device that includes the mating connector. The storage device additionally comprises memory that stores information relevant to usage of the storage device.
• In another aspect, the present invention relates to a storage device for storing a hydrogen fuel source. The storage device comprises a bladder that contains the hydrogen fuel source and conforms to the volume of the hydrogen fuel source in the bladder. The storage device also comprises a housing that provides mechanical protection for the bladder. The storage device further comprises a connector that interfaces with a mating connector included in a hydrogen fuel source refiner to permit transfer of the hydrogen fuel source from the hydrogen fuel source refiner to the bladder.
• In yet another aspect, the present invention relates to a hot swappable fuel storage system. The hot swappable system comprises a hydrogen fuel source storage device. The storage device includes a) a bladder that contains the hydrogen fuel source and conforms to the volume of the hydrogen fuel source in the bladder, b) a housing that provides mechanical protection for the bladder; and c) a connector. The hot swappable system also comprises a mating connector that interfaces with the connector to permit transfer of the hydrogen fuel source between the storage device and a device that includes the mating connector. The hot swappable system further comprises a fuel processor that includes a reformer configured to receive the hydrogen fuel source from the mating connector, configured to output hydrogen, and including a catalyst that facilitates the production of hydrogen. The hot swappable system additionally comprises a hot swappable reserve configured to store the hydrogen fuel source when the connector and mating connector are separated.
• In still another aspect, the present invention relates to system for providing a refillable hydrogen fuel source storage device. The system comprises a hydrogen fuel source storage device. The storage device includes a) a bladder that contains the hydrogen fuel source and conforms to the volume of the hydrogen fuel source in the bladder, b) a housing that provides mechanical protection for the bladder; and c) a connector that interfaces with a mating connector to permit transfer of the hydrogen fuel source between the bladder and a device that includes the mating connector. The system also comprises a hydrogen fuel source refiner including the mating connector and configured to provide hydrogen fuel source to the storage device when the connector is coupled to the mating connector.
• In another aspect, the present invention relates to a fuel cell system for producing electrical energy. The fuel cell system comprises a hydrogen fuel source storage device for storing a hydrogen fuel source. The storage device includes a bladder that contains the hydrogen fuel source and conforms to the volume of the hydrogen fuel source in the bladder. The storage device also includes a housing that provides mechanical protection for the bladder. The storage device further includes a memory that stores information relevant to usage of the storage device. The storage device additionally includes a connector that interfaces with a mating connector to permit transfer of the hydrogen fuel source between the bladder and a device that includes the mating connector. The fuel cell system also comprises a fuel processor. The fuel processor includes a reformer configured to receive the hydrogen fuel source from the mating connector, configured to output hydrogen, and including a catalyst that facilitates the production of hydrogen. The fuel processor also includes a burner configured to provide heat to the reformer. The fuel cell system also comprises a fuel cell including a fuel cell stack configured to produce electrical energy using hydrogen output by the fuel processor.
• These and other features and advantages of the present invention will be described in the following description of the invention and associated figures.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1A illustrates a fuel cell system for producing electrical energy in accordance with one embodiment of the present invention.
• FIG. 1B illustrates schematic operation for the fuel cell system ofFIG. 1A in accordance with a specific embodiment of the present invention.
• FIG. 2A shows a simplified hydrogen fuel source storage device in accordance with one embodiment of the present invention.
• FIG. 2B illustrates a cross sectional view of a hydrogen fuel source storage device in accordance with another embodiment of the present invention.
• FIG. 2C illustrates a bellows configuration used in the storage device ofFIG. 2B at its maximum volume.
• FIG. 2D illustrates a front view of a fuel source storage device in accordance with one embodiment of the present invention.
• FIG. 2E illustrates a front view of a storage device that is compatible with the storage device ofFIG. 2D in accordance with another embodiment of the present invention.
• FIG. 2F illustrates a front view of a storage device that is not compatible with the storage device ofFIG. 2D in accordance with one embodiment of the present invention.
• FIG. 2G illustrates a side view of the storage device ofFIG. 2F.
• FIG. 3 illustrates of a system for refilling a hydrogen fuel source storage device in accordance with one embodiment of the present invention.
• FIG. 4 illustrates of a system for producing electrical energy for a portable electronics device in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
• The present invention is described in detail with reference to a few preferred embodiments as illustrated in the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without some or all of these specific details. In other instances, well known process steps and/or structures have not been described in detail in order to not unnecessarily obscure the present invention.
• FIG. 1A illustrates afuel cell system10 for producing electrical energy in accordance with one embodiment of the present invention.Fuel cell system10 comprisesstorage device16,fuel processor15 andfuel cell20.
• Storage device16 andfuel processor15 provide hydrogen tofuel cell20.Storage device16 andfuel processor15 collectively act as a ‘reformed’ hydrogen supply that processes ahydrogen fuel source17 to produce hydrogen.Hydrogen fuel source17 acts as a carrier for hydrogen and can be processed to separate hydrogen.Hydrogen fuel source17 may include any hydrogen bearing fuel stream, aliphatic fuel source or other hydrogen carrier such as ammonia. Currently availablehydrocarbon fuel sources17 suitable for use with the present invention include methanol, ethanol, gasoline, propane, butane and natural gas, for example. Several hydrocarbon and ammonia products may also produce asuitable fuel source17.Liquid fuel sources17 offer high energy densities and the ability to be readily stored and shipped.
• Storage device16 stores fuelsource17, and may comprise a refillable and/or disposable fuel cartridge. A refillable cartridge offers a user instant recharging. In one embodiment, the cartridge includes a collapsible bladder within a hard plastic case.Storage device16 is portable and described in further detail below.
• A separate fuel pump typically controlsfuel source17 flow fromstorage device16. Ifsystem10 is load following, then a control systemmeters fuel source17 to deliverfuel source17 toprocessor15 at a flow rate determined by the required power level output offuel cell20.
• Fuel processor15 processes thehydrocarbon fuel source17 and outputs hydrogen. Ahydrocarbon fuel processor15 heats and processes ahydrocarbon fuel source17 in the presence of a catalyst to produce hydrogen.Fuel processor15 comprises a reformer, which is a catalytic device that converts a liquid or gaseoushydrocarbon fuel source17 into hydrogen and carbon dioxide. As the term is used herein, reforming refers to the process of producing hydrogen from a fuel source.
• Fuel cell20 electrochemically converts hydrogen and oxygen to water, generating electrical energy and heat in the process. Ambient air commonly supplies oxygen forfuel cell20. A pure or direct oxygen source may also be used for oxygen supply. The water often forms as a vapor, depending on the temperature offuel cell20 components. The electrochemical reaction also produces carbon dioxide as a byproduct for many fuel cells.
• In one embodiment,fuel cell20 is a low volume polymer electrolyte membrane (PEM) fuel cell suitable for use with portable applications such as consumer electronics. A polymer electrolyte membrane fuel cell comprises amembrane electrode assembly40 that carries out the electrical energy generating electrochemical reaction. Themembrane electrode assembly40 includes a hydrogen catalyst, an oxygen catalyst and an ion conductive membrane that a) selectively conducts protons and b) electrically isolates the hydrogen catalyst from the oxygen catalyst. A hydrogen gas distribution layer contains the hydrogen catalyst and allows the diffusion of hydrogen therethrough. An oxygen gas distribution layer contains the oxygen catalyst and allows the diffusion of oxygen and hydrogen protons therethrough. The ion conductive membrane separates the hydrogen and oxygen gas distribution layers. In chemical terms, the anode comprises the hydrogen gas distribution layer and hydrogen catalyst, while the cathode comprises the oxygen gas distribution layer and oxygen catalyst.
• A PEM fuel cell often includes a fuel cell stack having a set of bi-polar plates. A membrane electrode assembly is disposed between two bi-polar plates.Hydrogen distribution43 occurs via a channel field on one plate whileoxygen distribution45 occurs via a channel field on a second facing plate. Specifically, a first channel field distributes hydrogen to the hydrogen gas distribution layer, while a second channel field distributes oxygen to the oxygen gas distribution layer. The ‘term ‘bi-polar’ refers electrically to a bi-polar plate (whether comprised of one plate or two plates) sandwiched between two membrane electrode assembly layers. In this case, the bi-polar plate acts as both a negative terminal for one adjacent membrane electrode assembly and a positive terminal for a second adjacent membrane electrode assembly arranged on the opposite face of the bi-polar plate.
• In electrical terms, the anode includes the hydrogen gas distribution layer, hydrogen catalyst and bi-polar plate. The anode acts as the negative electrode forfuel cell20 and conducts electrons that are freed from hydrogen molecules so that they can be used externally, e.g., to power an external circuit. In a fuel cell stack, the bi-polar plates are connected in series to add the potential gained in each layer of the stack. In electrical terms, the cathode includes the oxygen gas distribution layer, oxygen catalyst and bi-polar plate. The cathode represents the positive electrode forfuel cell20 and conducts the electrons back from the external electrical circuit to the oxygen catalyst, where they can recombine with hydrogen ions and oxygen to form water.
• The hydrogen catalyst separates the hydrogen into protons and electrons. The ion conductive membrane blocks the electrons, and electrically isolates the chemical anode (hydrogen gas distribution layer and hydrogen catalyst) from the chemical cathode. The ion conductive membrane also selectively conducts positively charged ions. Electrically, the anode conducts electrons to a load (electrical energy is produced) or battery (energy is stored). Meanwhile, protons move through the ion conductive membrane. The protons and used electrons subsequently meet on the cathode side, and combine with oxygen to form water. The oxygen catalyst in the oxygen gas distribution layer facilitates this reaction. One common oxygen catalyst comprises platinum powder very thinly coated onto a carbon paper or cloth. Many designs employ a rough and porous catalyst to increase surface area of the platinum exposed to the hydrogen and oxygen.
• In one embodiment,fuel cell20 comprises a set of bi-polar plates formed from a single plate. Each plate includes channel fields on opposite faces of the plate. Since the electrical generation process infuel cell20 is exothermic,fuel cell20 may implement a thermal management system to dissipate heat from the fuel cell. Further description of a fuel cell suitable for use with the present invention is included in commonly owned co-pending patent application entitled “Micro Fuel Cell Architecture” naming Ian Kaye as inventor and filed on Jun. 25, 2004, which is incorporated by reference for all purposes.
• While the present invention will mainly be discussed with respect to PEM fuel cells, it is understood that the present invention may be practiced with other fuel cell architectures. The main difference between fuel cell architectures is the type of ion conductive membrane used. In one embodiment,fuel cell20 is phosphoric acid fuel cell that employs liquid phosphoric acid for ion exchange. Solid oxide fuel cells employ a hard, non-porous ceramic compound for ion exchange and may be suitable for use with the present invention. Generally, any fuel cell architecture may benefit from the fuel storage improvements described herein. Other such fuel cell architectures include direct methanol, alkaline and molten carbonate fuel cells.
• Fuel cell20 generates dc voltage that may be used in a wide variety of applications. For example, electrical energy generated byfuel cell20 may be used to power a motor or light. In one embodiment, the present invention provides ‘small’ fuel cells that are configured to output less than 200 watts of power (net or total). Fuel cells of this size are commonly referred to as ‘micro fuel cells’ and are well suited for use with portable electronics devices. In one embodiment,fuel cell20 is configured to generate from about 1 milliwatt to about 200 watts. In another embodiment,fuel cell20 generates from about 3 W to about 20W. Fuel cell20 may also be a stand-alone fuel cell, which is a single unit that produces power as long as it has an a) oxygen and b) hydrogen or a hydrocarbon fuel supply. A stand-alone fuel cell20 that outputs from about 40 W to about 100 W is well suited for use in a laptop computer.
• In one embodiment,fuel processor15 is a steam reformer that only needs steam and thefuel source17 to produce hydrogen. Several types of reformers suitable for use infuel cell system10 include steam reformers, auto thermal reformers (ATR) or catalytic partial oxidizers (CPOX). ATR and CPOX reformers mix air with the fuel and steam mix. ATR and CPOX systems reform fuels such as methanol, diesel, regular unleaded gasoline and other hydrocarbons. In a specific embodiment,storage device16 providesmethanol17 tofuel processor15, which reforms the methanol at about 250° C. or less and allowsfuel cell system10 use in applications where temperature is to be minimized. Further description of a fuel processor suitable for use with the present invention is included in commonly owned co-pending patent application entitled “Efficient Micro Fuel Cell Systems and Methods” naming Ian Kaye as inventor and filed on Jun. 25, 2004, which is incorporated by reference for all purposes.
• FIG. 1B illustrates schematic operation forfuel cell system10 in accordance with a specific embodiment of the present invention. As shown,fuel cell system10 comprises hydrogen fuelsource storage device16,hydrogen fuel source17,fuel processor15,fuel cell20, multiple pumps21 and fans35, fuel lines and gas lines, and one ormore valves23.
• Fuel container16 stores methanol as ahydrogen fuel source17. Anoutlet26 offuel container16 providesmethanol17 into hydrogenfuel source line25. As shown,line25 divides into two lines: afirst line27 that transportsmethanol17 to aburner30 forfuel processor15 and asecond line29 that transportsmethanol17 toreformer32 infuel processor15.Lines25,27 and29 may comprise plastic tubing, for example.Separate pumps21aand21bare provided forlines27 and29, respectively, to pressurize the lines and transmit the fuel source at independent rates if desired. A model P625 pump as provided by Instech of Plymouth Meeting, Pa. is suitable to transmit liquid methanol forsystem10 is suitable in this embodiment. A flow sensor orvalve23 situated online29 betweenstorage device16 andfuel processor15 detects and communicates the amount ofmethanol17 transfer betweenstorage device16 andreformer32. In conjunction with the sensor orvalve23 and suitable control, such as digital control applied by a processor that implements instructions from stored software, pump21bregulatesmethanol17 provision fromstorage device16 toreformer32.
• Fan35adelivers oxygen and air from the ambient room throughline31 to regenerator36 offuel processor15.Fan35bdelivers oxygen and air from the ambient room throughline33 to regenerator36 offuel processor15. In this embodiment, a model AD2005DX-K70 fan as provided by Adda USA of California is suitable to transmit oxygen and air forfuel cell system10. Afan37 blows cooling air overfuel cell20 and itsheat transfer appendages46.
• Fuel processor15 receivesmethanol17 fromstorage device16 and outputs hydrogen.Fuel processor15 comprisesburner30,reformer32 andboiler34.Burner30 includes an inlet that receivesmethanol17 fromline27 and a catalyst that generates heat with methanol presence.Boiler34 includes an inlet that receivesmethanol17 fromline29. The structure ofboiler34 permits heat produced inburner30 to heatmethanol17 inboiler34 beforereformer32 receives themethanol17.Boiler34 includes an outlet that providesheated methanol17 toreformer32.Reformer32 includes an inlet that receivesheated methanol17 fromboiler34. A catalyst inreformer32 reacts with themethanol17 and produces hydrogen and carbon dioxide. This reaction is slightly endothermic and draws heat fromburner30. A hydrogen outlet ofreformer32 outputs hydrogen toline39. In one embodiment,fuel processor15 also includes a preferential oxidizer that interceptsreformer32 hydrogen exhaust and decreases the amount of carbon monoxide in the exhaust. The preferential oxidizer employs oxygen from an air inlet to the preferential oxidizer and a catalyst, such as ruthenium or platinum, that is preferential to carbon monoxide over carbon dioxide.
• Fuel processor may also include adewar36 that pre-heats air before the air entersburner30. The dewar also reduces heat loss fromfuel cell20 by heating the incoming air before it escapesfuel processor15. In one sense, dewar acts as a regenerator that uses waist heat infuel processor15 to increase thermal management and thermal efficiency of the fuel processor. Specifically, waist heat fromburner30 may be used to pre-heat incoming air provided toburner30 to reduce heat transfer to the air in the burner so more heat transfers toreformer32.
• Line39 transports hydrogen fromfuel processor15 tofuel cell20.Gaseous delivery lines31,33 and39 may comprise plastic tubing, for example. A hydrogen flow sensor (not shown) may also be added online39 to detect and communicate the amount of hydrogen being delivered tofuel cell20. In conjunction with the hydrogen flow sensor and suitable control, such as digital control applied by a processor that implements instructions from stored software,fuel processor15 regulates hydrogen gas provision tofuel cell20.
• Fuel cell20 includes a hydrogen inlet port that receives hydrogen fromline39 and delivers it to a hydrogen intake manifold for delivery to one or more bi-polar plates and theirhydrogen distribution channels43. An oxygen inlet port offuel cell20 receives oxygen fromline33 and delivers it to an oxygen intake manifold for delivery to one or more bi-polar plates and theiroxygen distribution channels45. An anode exhaust manifold collects gases from thehydrogen distribution channels43 and delivers them to an anode exhaust port, which outlets the exhaust gases into the ambient room. A cathode exhaust manifold collects gases from theoxygen distribution channels45 and delivers them to a cathode exhaust port.
• In addition to the components shown in shown inFIG. 1B,system10 may also include other elements such as electronic controls, additional pumps and valves, added system sensors, manifolds, heat exchangers and electrical interconnects useful for carrying out functionality of afuel cell system10 that are known to one of skill in the art and omitted herein for sake of brevity.
• FIG. 2A shows a simplified hydrogen fuelsource storage device16 in accordance with one embodiment of the present invention.FIG. 2B illustrates a cross sectional view of astorage device16 in accordance with another embodiment of the present invention. Referring initially toFIG. 2A, hydrogen fuelsource storage device16 comprises abladder100,housing102,connector104 andmemory106.
• Bladder100 contains thehydrogen fuel source17 and conforms to the volume of the hydrogen fuel source in the bladder. In one embodiment,bladder100 comprises a compliant structure that mechanically assumes avolume115 according to a volume of liquid stored therein. Thevolume115 is formed bycompliant walls101 ofbladder100, which expand and/or open when fluid is added tobladder100, and contract and/or collapse when fluid is removed according to the negative pressure developed upon fluid removal. In one embodiment,bladder100 includes a sac that changes size and shape with the volume of liquid contained therein. Plastic, rubber, latex or a metal such as nickel are suitable materials for use with thewalls101 ofbladder100. In this case, thewalls101 are compliant and change size with a changingliquid volume115.FIG. 2B illustrates a bellows design forbladder100 that will be discussed in further detail below.Plastic walls101 may also comprise a fire retardant plastic material. One suitable fire retardant plastic material forwalls101 is NFPA-701-99 Test 1 Polyethelyne as provided by Plasticare of Orange Park, Fla. In another embodiment,bladder100 comprises a fixed cylinder and a piston that is pushed by a spring and moves in the cylinder to displace used fuel.
• Bladder100 is characterized by amaximum volume119 when the bladder fully expands.FIG. 2C illustrates the bellows configuration used in the storage device ofFIG. 2B at itsmaximum volume119. In a specific embodiment, maximum volumes forbladder100 range from about 20 milliliters to about 4 liters. Maximum volumes from about 20 milliliters to about 400 milliliters are suitable for many portable electronics applications. A maximum volume forbladder100 of 200 milliliters is suitable for laptop computer usage. Some extended run time systems may rely onstorage devices16 having 80 liters of maximum volume. The maximum volume forbladder100 may differ from the fuel source capacity ofstorage device16. In some cases,storage device16 comprisesmultiple bladders100 that each contributes a maximum volume that cumulatively add to a total fuel source capacity forstorage device16. For example, aspare storage device16 intended for electronics power back-up may contain twobladders100 each including 300 milliliters ofhydrogen fuel source17.
• While the present invention primarily refers to the storage of methanol inbladder100 andstorage device16, it is understood thatbladder100 andstorage device16 may contain other hydrocarbon fuel sources such as those listed above. In addition,bladder100 may contain a fuel mixture. For example, when thefuel processor15 fed bystorage device16 comprises a steam reformer,bladder100 may contain a fuel mixture of a hydrocarbon fuel source and water. Hydrocarbon fuel source/water fuel mixtures are often represented as a percentage fuel source in water. In one embodiment,hydrogen fuel source17 comprises methanol or ethanol concentrations in water in the range of 1%-99.9%. Alternatively,hydrogen fuel source17 may comprise 100% methanol or ethanol. Other liquid fuels such as butane, propane, gasoline, military grade “JP8” etc. may also be contained instorage device16 with concentrations in water from 5-100%. In a specific embodiment,bladder100 stores 67% methanol by volume.
• Housing102 provides mechanical protection forbladder100 and any other components ofstorage device16 included withinhousing102.Housing102 comprises a set ofrigid walls110 that containbladder100 and other internal components ofstorage device16. In one embodiment, all components ofstorage device16 are contained withinhousing102 save any portions ofconnector104 that protrude out of the housing for interface withmating connector140. In another embodiment,connector104 is recessed withinhousing102 andhousing102 provides an outer shell that substantially defines outer bounds and shape ofstorage device16.Walls110 collectively form an outer case or shell forstorage device16 that mechanically separates components internal tohousing102 from the external environment.Walls110 also collectively form aninterior cavity112.Interior cavity112 is a space within storage device that containsbladder100. As described below,interior cavity112 may comprises multiple compartments, each of which include aseparate bladder100.
• Rigid walls110 may comprise a suitably stiff material such as a plastic, metal (e.g., aluminum), polycarbonate, polypropelene, carbon fiber matrix, carbon composite material, etc.Rigid walls110 may also be formed from a fire retardant material such as a fire retardant plastic material. One suitable fire retardant plastic material forwalls110 is 8-12% weight, JLS-MC mixed with PA66 Polyamide as provided by JLS Chemical of Pomona, Calif.Rigid walls110 may be designed according to criteria for construction of thin walled pressure vessels. Such criteria are known to those of skill in the art. In this case,walls110 andhousing102 may be designed to withstand a maximum pressure withininternal cavity112 or forbladder100.
• Housing102 may include an elliptical (including circular) shape, a rectangular shape with chamfered corners, or other substantially consistent profile or shape in a given direction.FIGS. 2D-2F illustrate somesuitable housing102 shapes. For the embodiment ofFIG. 2B,housing102 includes a substantially consistent shape in adirection125 that extends normally away from atube107 inconnector104. In one embodiment,housing102 comprises a transparent section or clear window to allow for visual fuel gauging.
• In one embodiment,housing102 is integrally formed to prevent disassembly ofhousing102. In this case,walls110 may be permanently bonded or extruded from a common material in one piece such that access intohousing102 is only gained through destruction ofwalls110 andhousing102.
• Connector104 interfaces with a mating connector140 (seeFIG. 2B) included in an external device. Together,connector104 andmating connector140 permit transfer offuel source17 betweenbladder100 and the external device. Whenmating connector140 is included infuel processor15 or a device that includesfuel processor15,connector104 andmating connector140 interface to permit transfer offuel source17 fromstorage device16 to thefuel processor15. Alternatively, whenmating connector140 is included in a hydrogen fuel source refiller,connector104 andmating connector140 interface to permit transfer offuel source17 from the refiner tostorage device16. Interface betweenconnector104 andmating connector140 may comprise any relationship and mating structures that permit fluid communication between the two connectors.Connector104 and/ormating connector140 may also include mechanical coupling to secure the interface, such as latching elements that bindconnector104 andmating connector140 together until physically released.Connector104 andmating connector140 may also each include electrical leads that contact when the connectors are attached to enable electrical and digital communication.
• Connector104 andmating connector140 each comprise a geometry that at least partially matches geometry of the other.Exemplary connector104 andmating connector140 geometries are described below with respect toFIGS. 2D-2G.
• In one embodiment,connector104 incorporates a quick disconnect that permitsstorage device16 to be readily removed by pulling onhousing102. This separatesconnector104 andmating connector140 and detaches any electrical links and plumbing responsible for fluid communication betweenstorage device16 and the device includingmating connector140. Asecond storage device16 with aquick disconnect connector104 may then be readily inserted back intomating connector140. The quick disconnect thus allows rapid replacement ofstorage device16 with anotherstorage device16 when fuel source volume levels are low. Thequick disconnect connector104 includes one port or multiple ports according to the plumbing needs of storage device16 (e.g., fuel provision and a scrubbing bed). Aquick disconnect connector104 may also include other features to control removal requirements such as two handed operation or a high force actuator. Commercially available quick disconnect connectors are available from a variety of vendors. One suitable quick disconnect connector is model number QDC101 as provided by Beswick of Greenland, N.H. As will be described in further detail below,storage device16 may also include a hot swappable capability that improves quick disconnect usage forconnector104 andmating connector140.
• Connector104 andmating connector140 may provide an automatic shutoff capability whendevice16 is removed fromsystem202. In this case, each only open when connected to the other and whendevice16 interfaces withdevice202. In one embodiment,device16 comprises a small sponge or swab located on or nearconnector104 to collect any fuel leakage during device connection or disconnect.
• In one embodiment, one ofconnector104 andmating connector140 includes a ‘male’ designation and configuration while the other includes a ‘female’ designation and configuration. The male configuration includes portions of the connector that protrude, such as one or more pins or electrical leads. The female configuration includes portions of the connector that receive the male portions, such as holes electrically lined to receive the male portion and facilitate electrical communication. As shown inFIG. 2G,connector104 onstorage device16 includes a female configuration that recesses withinhousing102. Since it is recessed,connector104 cannot be knocked off during rough handling.Mating connector140 is configured on a side portion of an OEM device (i.e., a laptop computer). As will be described in further detail below,mating connector140 is also included in refilling hardware that refillsstorage device16 withfuel source17.
• Memory106 stores information relevant to usage ofstorage device16.Memory106 may comprise a mechanical, electrical and/or digital mechanism for information storage. In one embodiment,memory106 comprises a digital memory source that permits an external controller to read and write from the digital memory. In another embodiment,memory106 includes a mechanical device. One suitable mechanical device comprises “break-off” pins158 (seeFIG. 2D). Other forms ofmechanical memory106 may comprise discs or rods which are removed or otherwise manipulated every time astorage device16 is refilled. For the embodiment shown inFIG. 2D,memory106 is external tohousing102 and comprises a visible identification tag that uniquely identifiesstorage device16. Various types of external identification tags are known in the art and may be used with this invention. Two examples of identification identifier tags include magnetic recording devices and optical bar codes.
• In one embodiment,storage device16 is considered ‘smart’ sincememory106 stores information related to the performance, status and abilities ofstorage device16. A digital memory allows an external controller or logic to read and write information relevant to usage of the storage device tomemory106. Reading from adigital memory106 allows reception and assessment of information inmemory106 to improve usage ofstorage device16. For example, a computer that receivesstorage device16 may inform a user that thestorage device16 is empty or how much fuel is left (or how much time on the system is available based on its power consumption and the amount of fuel remaining). Writing to adigital memory106 allows information inmemory106 to be updated according tostorage device16 usage. Thus, if a user nearly depletesfuel source17 instorage device16 while powering a computer, the next user may be informed after the first computer writes an updated amount offuel source17 remaining instorage device16 intomemory106.
• Storage device16 specifications stored inmemory106 generally do not change withdevice16 usage and may comprise a) a fuel type stored in the storage device whendevice16 is dedicated to service a particularhydrocarbon fuel source17, b) a model number forstorage device16, c) an identification signature for the manufacturer ofstorage device16, d) manufacture date, and e) a volume capacity forbladder100 orstorage device16. The model number ofdevice16 allows it to be distinguished from a number of similar devices.
• Transient information stored inmemory106 that changes according to the status and usage ofstorage device16 may comprise a) hydrogen fuel mixture information, b) a number of refills provided tostorage device16 whendevice16 is configured for re-usable service, c) the last refill date, d) the refilling service provider that refilledstorage device16 when the device is configured for re-usable service, e) usage history according to a storage device identification, and f) a current volume for the storage device.
• Referring now toFIG. 2B,storage device16 comprises abladder100 with acollapsible bellows configuration126,housing102,connector104,memory106,air vent132,filter134,pressure relief valve136,fire retardant foam138,mechanical shield142, andfuel source filter144.Connector104 comprisestube107 andfemale bay117.Storage device16 connects to alaptop computer202, which includesmating connector140.Mating connector140 comprisestube109,reserve volume302 andmale housing113.
• Mating connector140 interfaces withconnector104 to permit transfer ofhydrogen fuel source17 fromstorage device16 tolaptop computer202. In one embodiment,storage device16 resembles a battery-sized cartridge including afemale connector104 that receives amale mating connector140.Male housing113 ofmating connector140 fits snugly into afemale bay117 of connector104 (seeFIG. 2G for side view of a bay117). The fit provides mechanical support for the interface betweenmating connector140 andconnector104. Distal end oftube107 instorage device16 and a distal end oftube109 inmating connector140 align whenconnector104 andmating connector140 join. In a specific embodiment,tube109 comprises a pointed end that pierces intotube107 andtube109 comprises a diameter that snugly fits intotube107 whenconnector104 andmating connector140 are attached.
• Whenmating connector140 andconnector104 are joined as shown, a pump run by afuel cell system10 withinlaptop computer202 draws fluid frombladder100 into thefuel cell system10. More specifically,fuel source17 travels frombladder100, throughtube107 inconnector104, into and throughtube109 inmating connector140, and throughtube109 inlaptop computer202 to afuel processor15 included therein.
• Connector104 andmating connector140 may also include electrical connectivity for digital communication betweenmemory106 and a processor or controller (seeFIG. 4) onlaptop computer202.FIG. 2F illustrates femaleelectrical slots155 onconnector104b. Amating connector140 forconnector104bthen includes male leads (not shown) that fit intoslots155 for electrical communication betweenlaptop computer202 andstorage device16.
• For the embodiment ofFIG. 2B,bladder100 comprises acollapsible bellows design126. Oneend127aofbellows126 attaches and opens totube107, while theopposite end127bis free to move indirection125. Whenbladder100 fills withfuel source17,free end127bmoves indirection125 and bellows126 expands and increases in volume. Whenbladder100 losesfuel source17,free end127bmoves opposite todirection125 and bellows126 collapses and decreases in volume.Free end127bandbladder100 thus compresses towards the location wherefuel source17 is outlet and where negative pressure is created to contract or collapse bellows126 (tube107 andconnector104 in this case).FIG. 2C illustrates abellows configuration126 at its maximum volume. As shown inFIG. 2B,bladder100 is less than half full offuel source17 and assumes less than half the space ininternal cavity112.Bellows126 comprisescollapsible rings128 that fold asbellows126 expands (the angle of eachring128 opens) and asbellows126 collapse (the angle of eachring128 closes).Bellows126 may comprise plastic or Nickel, for example.Bellows126 may be custom molded or electroformed. Similarly designed bellows are used to protect tubular warp in machine tools, for example. Servometer Corp. of New Jersey provides several suitable commercially available nickel bellows.
• Storage device16 includes anair vent132 inhousing102 that allows air to enter and exit ininternal cavity112 withinhousing102 asbladder100 changes in volume.Air vent132 comprises one or more holes or apertures in awall110 ofhousing102. In operation, asfuel source17 is consumed and drawn fromstorage device16,bladder100 collapses and creates a negative pressure ininternal cavity112 outside ofbladder100. Based on this negative pressure caused by a decreasing volume of bladder100 (or increasing volume ofinternal cavity112 outside bladder100), air enters throughair vent132 intointernal cavity112 and displaces the decreasing volume ofbladder100. This prevents the pressure offuel source17 inbladder100 from decreasing and affecting the ability ofstorage device16 to providefuel source17 at a substantially constant pressure. When fillingstorage device16, positive pressure caused by an increasing volume offuel source17 andbladder100 causes air to exit throughair vent132. Since walls ofbladder100separate fuel source17 withinbladder100 from air ininternal cavity112, air incavity112 does not enterbladder100 or mix withfuel source17.
• Afilter134 spans the cross section ofair vent132 and intercepts air passing throughair vent132. In one embodiment,filter134 comprises a hydrophobic and gas permeable filter that prevents foreign materials from enteringstorage device16. Materials blocked byfilter134 may include liquids and particles such as undesirable oils and abrasives that may affectstorage device16 performance. The hydrophobic filter also preventsfuel source17 from escapinghousing102 in the event thatbladder100 develops a leak.Filter134 may comprise micro porous Teflon or another micro porous material such as Teflon coated paper. A sintered metal filter, for example one with a 3 micron pore size, may also be used. Onesuitable filter134 includes micro porous “Gore Tex” Teflon as provided by WL Gore Associates of Elkton, Md.
• Mechanical shield142 spans and coversair vent132 and prevents foreign bodies from enteringhousing102 throughair vent132 anddamaging bladder100. In one embodiment,air vent132 is recessed into awall110 such thatmechanical shield142 is flush with the outer surface ofhousing102. As shown,filter134 is located internal to shield142 such thatshield142 mechanically protectsfilter134. In one embodiment,mechanical shield142 includes a flame suppressor or a suitable means of flame suppression. Themechanical shield142 then prevents flame propagation into or out frominterior cavity112. One suitablemechanical shield142 includes cut to size 180×180 mesh stainless steel screen as provided by McNichols of Tampa, Fla.
• Pressure relief valve136 limits pressure instorage device16. More specifically,pressure relief valve136releases fuel source17 frombladder100 when the pressure withinbladder100 reaches a threshold pressure. The threshold pressure refers to a pressure forbladder100 that represents the upper limit of operational pressure forfuel source17 use instorage device16. Threshold pressures from about 5 psig to about 25 psig are suitable for somefuel sources17 andstorage devices16. A threshold pressure of about 15 psig is suitable in many cases. Other suitable threshold pressures may relate to the boiling point of thefuel source17, which ranges from about 2 Atm to about 10 Atm. Thus, if temperature forstorage device16 rises above the boiling point offuel source17, the threshold pressure is reached andpressure relief valve136releases fuel source17 frombladder100. During normal operation and storage, the partial pressure offuel source17 inbladder100 is less than the threshold pressure andpressure relief valve136 is not used. In the event that pressure offuel source17 inbladder100 rises above the threshold pressure,pressure relief valve136releases fuel source17 frombladder100, thereby limiting the pressure withinbladder100.
• In a specific embodiment,pressure relief valve136 comprises a sprung diaphragm mechanism. The sprung diaphragm includes a diaphragm and a spring that attaches to the diaphragm. Pressure inbladder100 pushes the diaphragm outward against the spring force. At the threshold pressure, the diaphragm opens a port—a small hole that opens outside ofhousing102—to permit the release offuel source17 frombladder100. Spring selection permits a designer to control the threshold pressure at which the port opens andfuel source17 escapes. In another specific embodiment,pressure relief valve136 comprises a burst disk mechanism that includes a thin diaphragm. The diaphragm breaks outward when pressure inbladder100 rises above the threshold pressure. The diaphragm break and the resultant opening releasesfuel source17 frombladder100. For either design, the port or opening may be configured to direct venting fuel vapors away fromstorage device16 and into a ventilated area when installed in an electronics or OEM device.
• Afuel source filter144intercepts fuel source17 as it leavesbladder100 and before it leavesconnector104. As shown,filter144 spans an entrance totube107 frombladder100.Fuel source filter144 removes any contaminants or chemicals added to fuelsource17 for storage inbladder100 anddevice16. In one embodiment,fuel source17 comprises anodorant150, abitterant152 and/or acolorant154 mixed therein. Iffuel source17 comprises an odorless liquid,odorant150 provides olfactory stimulus to inform a person that fuelsource17 has escapedbladder100 andstorage device16 via a path other than throughtube107 andfilter144. Twosuitable odorants150 includes trimethyl amine at 1-10 ppm in methanol and ethyl mercaptan at 1-7 ppm weight in methanol.Fuel source filter144 removesodorant150 fromfuel source17 when the fuel source leavesbladder100 throughtube107.
• Iffuel source17 comprises a colorless liquid,colorant154 provides visual stimulus to inform a person that fuelsource17 has leaked or escaped frombladder100 via a path other than throughtube107 andfilter144.Suitable colorants154 include acid blue9 at 1 ppm, table 5-4 food dye, and bright green/blue erioglaicine disodium salt as provided by Dudley Chemical Corp of Lakewood, N.J.Fuel source filter144 removescolorant154 fromhydrogen fuel source17 when the fuel source leavesbladder100 throughtube107.
• Iffuel source17 comprises liquid with no taste, abitterant152 may be added to provide taste stimulus that informs a person that fuelsource17 has escapedbladder100 via a path other than throughtube107 andfilter144. Onesuitable bitterant152 includes Denatonium Benzoate at 1-50 ppm (20-50 ppm is adversely bitter) as provided by Bitrex of Edinburgh, UK.Fuel source filter144 removes bitterant152 fromhydrogen fuel source17 whenfuel source17 leavesbladder100 throughtube107. Onesuitable filter144 for removingodorant150,bitterant152 and/orcolorant154 includes an ultra-pure polyethersulfone membrane. Anothersuitable filter144 for removingodorant150,bitterant152 and/orcolorant154 fromfuel source17 includes 0.1 Advantage PS C-7012 filter as provided by Parker Hanafin Corp.
• Afire retardant foam138 is disposed inbladder100.Foam138 is compliant and conforms in size to the size ofbladder100. Thus, asbladder100 collapses,foam138 compresses. In one embodiment,foam138 acts as a wicking foam that directs some flame behavior instorage device16. Onesuitable foam138 is polyurethane mil Spec Mil-B-83054 as provided by Foamex of Lindwood, Pa.
• In one embodiment,memory106 comprises a wireless identification (ID) tag. This allowsmemory106 to communicate with an external device, such as hydrogenfuel source refiner162 described inFIG. 3. In this case, the external device includes an interrogator that probesmemory106 via wireless communication whenstorage device16 is in range of the interrogator. The interrogator may include any hardware for performing this function such as a computer, transceiver and interrogator antenna. Coupling between the interrogator andstorage device16 may occur via radio frequency (RF) or microwave frequency radiation. When probed by the interrogator,storage device16 replies with its identification (as stored in a digital or electrical memory106) and any other information stored inmemory106, such as the status of any sensors used instorage device16 to monitor health of the device and sensors that detect the volume of fuel source inbladder100. Thestorage device16 identification provides a means for automated logging of data corresponding to the status ofstorage device16. The identification also facilitates inventory logging of information fornumerous storage devices16.
• In one embodiment, the interrogator provides power tostorage device16. The power is transmitted by RF waves, for example, and received by a rectifier instorage device16 that rectifies the signal, thereby providing sufficient DC power to operate any circuitry ofstorage device16. A transponder included instorage device16 responds to a wireless stimulus. The transponder transmits signals when actuated by a signal from an external interrogator. In some cases, the transponder includes an amplifier for increasing the strength of a received incident signal, a modulator for modifying the signal with information stored bymemory106, and an antenna or antennas for receiving and transmitting signals.
• Wireless ID tags are commercially well known and there exists numerous manufacturers that currently offer a wide selection of RFID tags. These tags are either passive (typically operating near 125 kHz) or active (often operating near 2.45 GHz). Major manufacturers include Texas Instruments of Dallas, Tex. and Motorola of San Jose, Calif. or Alien Technologies of San Jose, Calif. Products are available for inventory control, product labeling, etc. For example,storage device16 may use a commercial RFID tag, such as a 125-kHz tag supplied by Texas Instruments of Dallas, Tex., which includes a microchip formemory106 and inductor for wireless communication.
• Storage device16 may also comprise a sensor that monitors a condition related to the health or functioning ofstorage device16. In one embodiment, the sensor comprises awire156 that runs about an inside surface ofhousing102 or is formed within awall110 housing102 (seeFIG. 2C). An electrical state or performance ofwire156 provides an indication of the health ofhousing102. Mechanical damage, cracking or structural compromise ofhousing102 affectswire156—mechanically and electrically. More specifically, whenwire156 breaks, stretches or loses contact due to mechanical changes housing102, an electrical signal sent throughwire156 changes. The according change may be read and assessed. Thus, a break inwire156 may be read by non-transmittance of a signal. Changes in electrical resistance ofwire156 may also provide an indication of health. In one embodiment, the sensor relies on external (e.g., RFID) probing to assess the state ofwire156 and health ofhousing102. In this case, the interrogator powersmemory106 to test the resistance ofwire156. TheRFID memory106 then responds with a signal indicative of the status ofwire156. Although the sensor is shown as asingle wire156, it is understood that more complex designs may comprise filament networks that extend two dimensionally throughouthousing102. Each filament may then be probed for its electrical status, e.g., resistance to provide a meshed status check of integrity and health ofhousing102 andstorage device16.
• FIG. 2D illustrates a front view of fuelsource storage device16ain accordance with one embodiment of the present invention.FIG. 2E illustrates a front view of astorage device16bthat is partially compatible withstorage device16a.FIG. 2F illustrates a front view of astorage device16cthat is not compatible withstorage device16a.FIG. 2G illustrates a side view of astorage device16c.
• Connector104 and/ormating connector140 may include a ‘keyed’ configuration that provides interface selectivity. For example,connector104 may comprise a configuration unique to a particular hydrogen fuel source (e.g., methanol). In this case,mating connector140 offers an exclusive interface that only receives aconnector104 for a methanol basedstorage device16. This keying system prevents the wrong fuel type from being installed in a device that cannot accept that fuel, e.g., gasoline burns at a higher temperature and may not be suitable for use in all methanol fuel processors. This keying system also preventsstorage device16 from being refilled with the wronghydrogen fuel source17.
• For example,storage device16aofFIG. 2D includes acircular connector104athat interfaces with a circular mating connector (not shown). Similarly,storage device16bofFIG. 2E includes acircular connector104aof the same dimensions that interfaces with the same circular mating connector as that employed forconnector104a. Thestorage device16cofFIG. 2F includes arectangular connector104bthat would not interface with the same circular mating connector.Circular connectors104amay be used for methanol fuel mixtures of different blends for example, whilerectangular connector104bis used for ethanol.
• The keyed configuration of connector also allows for variation of one ofconnector104 ormating connector140, while the other remains constant. This controlled variability has numerous commercial applications. In one commercial system,connector104 may change slightly whilemating connector140 remains constant. Acommon mating connector140 may receivedifferent storage devices16 that share aconnector104aconfiguration. Thedifferent storage devices16 may be produced by different manufacturers and may include varying volumes orother storage device16 features. This permits competition for the provision ofstorage devices16 but standardization of their interface. In another commercial application, an electronics device manufacturer such as Dell specifies acustom mating connector140 configuration (e.g., a circular configuration used in their laptop computers and other electronics devices). Allstorage devices16 that service these electronics devices must then include aconnector104 that matches Dell'scustom mating connector140 configuration. The electronics device manufacturer may then control who manufacturersstorage devices16 andconnectors104 for use with their electronics devices.Keyed connectors104afor one electronics device manufacturer may also be designed to not fit amating connector140 for another computer manufacturer, e.g., Apple employs arectangular configuration104b.
• Custom connector104 andmating connector140 configurations may vary based on geometry, dimensions, depth and size for example. Aconnector104 ormating connector140 may also include one ormore features149 that distinguish a custom connector or mating connector. As shown inFIG. 2E, feature149 is a tab that extends into thefemale bay117 of connector and mechanically distinguishesstorage device16bfromstorage device16a.
• Connector104/mating connector140 configuration selectivity may also be implemented to distinguish developing technology infuel cell system10 orstorage device16. By changingmating connector140 to receive onlycertain connectors104, the present invention permits continuing development offuel cell system10 orstorage device16 and ensures rejection ofprevious storage device16 models that are no longer suitable. For example,storage device16bmay represent a newer version ofstorage device16athat is mechanically distinguished byfeature149. An electronics device that receivesstorage devices16 may include amating connector140 that mechanically rejectsstorage device16abased omission offeature149.Memory106 may also be digitally read to indicate incompatibility.
• The keyed configurations shown inFIGS. 2D-2F may also be implemented forparticular fuel source17 types. For example,storage device16aandconnector104amay designate a methanol fuel mixture ‘A %’, whilestorage device16band feature149 designate a methanol fuel mixture ‘B %’ andstorage device16candconnector104bdesignates an ethanol fuel mixture.
• Storage devices16aalso comprise “break-off” pins158 that form amechanical memory106.Pins158 indicate the number of refills for eachstorage device16. Eachtime storage device16 is refilled, the refiner breaks apin158. When all the pins have been removed, a mating connector toconnector104 will not acceptstorage device16.Pins158 may comprise plastic and be molded into thecartridge housing102 or toconnector104.
• In one embodiment,storage device16 is intended for disposable use. In this case, a user purchases astorage device16 with a full complement of methanol and disposes ofstorage device16 after it is emptied. In another embodiment,storage device16 is intended for reusable use. Areusable storage device16 provides less waste. In this case,storage device16 is refilled by a hydrogen fuel source refiller.
• FIG. 3 Illustrates asystem160 for providing a refillable hydrogen fuelsource storage device16 in accordance with one embodiment of the present invention.System160 comprisesstorage device16 and a hydrogenfuel source refiner162.
• Hydrogenfuel source refiner160 includesmating connector140 and is configured to providehydrogen fuel source17 tostorage device16 when theconnector104 is coupled tomating connector140.Connector104 andmating connector140 interface to permit transfer offuel source17 fromrefiner160 tostorage device16.Refiller160 comprises afuel reserve tank164 that storeshydrogen fuel source17. Tank is suitably size to refuelnumerous storage devices16. Apump166 receives control signals from arefiner controller168 that controls functioning ofrefiner160 based on stored commands inrefiller memory170.Refiller memory170 may also include a database that stores information for eachstorage device16 serviced byrefiner160.
• Aline172 transportsfuel source17 fromtank164 tostorage device16. More specifically, pump166 movesfluid fuel source17 fromtank164 throughtube109 inmating connector140, into and throughtube107 inconnector104, and intobladder100 for storage therein. Althoughrefiner160 is shown refilling asingle storage device16, it is understood thatrefiller160 may comprise multiple ‘bays’ that each include amating connector140 and plumbing to refill asingle storage device16.Refiller160 may also includemultiple tanks164 that provideddifferent fuel sources17, such as different fuel sources (e.g., methanol or ethanol) or different fuel mixtures.
• Controller168 also communicates withmemory106 vialine174, which travels fromcontroller168, through electrical connectivity provided byconnector104 andmating connector140 and tomemory106.Controller168 may also communicate withmemory106 via wireless means as described above ifcontroller168 andmemory106 both include such capability.Refiller160 includes aninterrogator176 to communicate wirelessly with astorage device16.Interrogator176 comprises a transceiver and antenna based on the communication frequency employed.
• Controller168 reads from and writes tomemory106.Controller168 may read and store the usage history of adigital memory106. Whenstorage device16 includes a mechanical memory such as the break-offpins158 described above,refiner162 checks if there are anypins158 remaining (either mechanically or electronically). If all the pins have been removed,refiner162 does not acceptstorage device16.Controller168 may also check the status of any sensors onstorage device16 used to monitor health of thedevice16, such as an RDIF sensor that detects housing integrity. This helps a re-filling services provider determine ifstorage device16 can be simply be refilled, or if it needs to refurbished as well. Viacontroller168 and stored logic that dictates responses to information read frommemory106,refiner162 is thus configured to detect a defect instorage device16 and not transferhydrogen fuel source17 tostorage device16 when a predetermined memory element is present. Memory elements may include use of a pressure relief valve or information related to the status of any sensors onstorage device16.
• Controller168 may also write intomemory106 information such as: the hydrogen fuel mixture information stored therein, an updated number of refills provided tostorage device16, the refill date, the refilling service provider, and a volume for the storage device. Whenstorage device16 includes a mechanical memory such as the break-offpins158 described above,refiner162 breaks apin158 upon refill completion.
• Refillable system160 allows distribution of thehydrogen fuel source17 to be handled flexibly. One approach is to distributerefillable storage devices16 similar to the distribution of batteries. A consumer purchases a desiredstorage device16 at a retail outlet, such as a department store, super market, airport kiosk or drug store etc.Storage device16 selection may vary based onfuel source17 capacity,fuel source17 type or other features such as connectivity and smart features.Spent storage devices16 may be dropped off at the any of the above locations for reuse, and shipped to a refilling services provider for refurbishment and refill.
• Whenstorage device16 comprises a hydrogen fuel cleaning system,refiner162 may also rejuvenate or check for replacement of the cleaning system. For the scrubbing bed as described below with respect to filter220,refiner162 rejuvenates the cleaning system by forcing hydrogen through the bed (e.g., using hydrogen in tank164). The scrubbingbed filter220 may also be replaced with a new bed when thestorage device16 is refilled.
• Refillingsystem160 allows ahydrogen fuel source17 refilling provider to control refilling ofstorage devices16.Connectors104 that require specific parts onmating connector140 to complete interface and permit fluid transfer intostorage device16 also prevent free tampering and addition of fluids tostorage device16. Refillingsystem160 also provides a business model for distribution ofstorage devices16. Refillingsystem160 also permits thehydrogen fuel source17 refilling provider to certify fuel blends, monitor the number of refills for aparticular storage device16, and validatestorage device16 for consumer or manufacturer confidence.
• FIG. 4 shows a schematic illustration of asystem200 for producing electrical energy for a portable electronics device in accordance with one embodiment of the present invention.System200 comprisesfuel processor15 andfuel cell20 included within anelectronics device202 and a hydrogen fuelsource storage device16 coupled toelectronics device202 viaconnector104 andmating connector140.Electronics device202 may comprise any portable or stationary electronics device or power application that relies on a fuel cell to generate electrical energy.
• In one embodiment,fuel processor15 andfuel cell20 are incorporated into electronics device202 (within its volume and outer housing) as an integral module, andstorage device16 is removable allowing for instant recharging. Fuel cell poweredlaptop computers202 may comprise slightly modified existing products, withfuel processor15 andfuel cell20 and related system components fitted generally into the space provided for a battery pack.Mating connector140 is included in this allocated space for connection tostorage device16.Storage device16 mechanically interfaces withelectronics device202. In one embodiment,connectors104 and140 provide sufficient mechanical force to maintain position between thestorage device16 andelectronics device202. In another embodiment,electronics device202 includes a mechanical slot thatstorage device16 fits and slides into. In one embodiment, an external cartridge-mounting bracket is provided to allow forlarger storage devices16 to be used.
• Whenconnector104 andmating connector140 interface, fuelcell system controller214 digitally communicates withmemory106 usinglink217 for bi-directional communication therebetween. In another embodiment,controller214 uses a wireless interrogator to communicate with an RFID antennae andmemory106 included instorage device16.Controller214 may read any information stored inmemory106 such as a fuel type stored in thestorage device16, a model number forstorage device16, a volume capacity forbladder100 orstorage device16, a number of refills provided tostorage device16, the last refill date, the refilling service provider, and a current volume for the storage device. In one commercial application,different bladder100 volumes andstorage device16 configurations are offered based on different laptop computer manufacturers and models for a particular manufacturer. The volume may be configured to meet a specific run time requirement for a particular laptop model, for example. In this case,controller214 estimates the remaining power instorage device16 by comparing thefuel source17 level since last use or refill against a consumption rate for a particular laptop computer.
• Controller214 may also write transient information tomemory106, such as an updated volume for the storage device. Thecontroller214 communicates with amain controller210 forcomputer202 andcomputer memory218 viacommunications bus212.Computer memory218 may store instructions for the control offuel system10 such as read and write protocol and instructions for communication with adigital memory106.
• System200 also comprises a hydrogen fuel cleaning system. As shown,storage device16 comprises afilter220 in fluidic communication withhydrogen224 output byfuel processor15.Filter220 removes contaminants from thehydrogen224 stream (or reformate) before receipt byfuel cell20. The reformate often includes hydrogen, carbon dioxide, carbon monoxide and other small particulates.Filter220 may remove carbon monoxide, un-converted methanol vapor and/or hydrogen sulfide (among others). As shown, line226 routes reformate224 output by a hydrogen outlet offuel processor15, back throughmating connector140 andconnector104, intostorage device16 and throughfilter220, back out of instorage device16 and to an anode inlet offuel cell20. In a specific embodiment,filter220 comprises a carbon monoxide scrubbing catalyst or absorbent arranged in a bed thathydrogen224 stream passes through. The bed is filled with a material, such as activated carbon, potassium permanganate or cupric chloride (CuCl₂). The catalyst or absorbent absorbs CO, methanol vapor or H₂S. As described above, the scrubbing bed may be rejuvenated by passing hydrogen through the bed when thestorage device16 is refilled. Or the scrubbing bed may be replaced with a new bed when thestorage device16 is refilled.Filter220 simplifies chemical management forfuel processor15 and increases the performance offuel cell20.Filter220 also reduces poisoning of thefuel cell20 catalysts with un-converted methanol vapors, by trapping the vapors prior to thehydrogen224 stream enteringfuel cell20. In another embodiment, a line routes unused hydrogen fromfuel cell20 in the anode exhaust tofuel processor15 to further increase efficiency of the fuel cell system indevice202. Further discussion of fuel cell systems suitable for use with the present invention are described in commonly owned co-pending patent application entitled “Micro Fuel Cell Architecture” naming Ian Kaye as inventor and filed on Jun. 25, 2004, which is incorporated by reference for all purposes.
• Power management216 controls power provision byfuel cell system10 andelectrochemical battery222. Thus,power management216 may informcontroller214 how much power is needed forlaptop computer202 operation andcontroller214 responds by sending signals tofuel cell20,fuel processor15 and a pump that draws fuel fromstorage device16 to alter fuel cell power production accordingly. Iffuel cell system10 runs out offuel source17, thenpower management216 switches to electrical power provision frombattery222.
• Aspare storage device16dis included insystem200.Storage device16dshares aconnector104 withstorage device16a(currently plugged in).Storage device16dcomprises a dualinternal compartment112aand112bconfiguration internal to housing102ddivided byinternal wall110d.Internal compartment112aincludes afirst bladder100bwhileinternal compartment112bincludes asecond bladder100b. The dual bladder design ofstorage device16dprovides extended power back up forsystem200.
• System200 may also be configured for ‘hot swappable’ capability. As the term is used herein, hot swapping ofstorage device16 refers to removingstorage device16 from a fuel processor or electronics device it provideshydrogen fuel source17 to, without shutting down the receiving device or without compromising hydrogen fuel source provision to the receiving device for a limited time. A hot swappable system implies fuel source provision whenconnector104 andmating connector140 are separated. Referring back toFIG. 2A,electronics device202 comprises areserve volume302 that is configured to store thehydrogen fuel source17 whenconnector104 andmating connector140 are separated.
• The time that a receiving fuel processor or electronics device may be operated for whileconnector104 andmating connector140 are separated relates to the amount of fuel inreserve volume302 and the rate at which the fuel processor or electronics device usesfuel source17. A maximum volume forreserve volume302 characterizes the capacity offuel source17 thatreserve volume302 can store. In one embodiment,reserve volume302 includes a maximum volume between about 1 milliliter and about 50 milliliters. A maximum volume between about 1 milliliter and about 4 milliliters may be suitable for some portable electronics applications.
• For thestorage device16 shown inFIG. 2C,reserve volume302 comprises the volume oftube109 between its upstream end where it interfaces withconnector104 and its downstream end where it opens to thefuel processor15. The inner diameter oftube109 may be configured to provide a particular volume maximum forreserve volume302. In one embodiment,tube109 comprises plastic tubing with an outer diameter less than ¼ of an inch and a tube wall thickness between about 10 and about 50 mils.
• For thestorage device16 shown inFIG. 2B,reserve volume302 comprises a cavity withinconnector140 that acts as a small reservoir forfuel source17 entering theelectronics device202. The cavity permits larger maximum volumes forreserve volume302. The cavity may alternatively be configured downstream ofconnector140 within thedevice202 to receivefuel source17 fromline109 after it passes throughconnector140, e.g., closer to fuelprocessor15. In this case, the maximum volume forreserve volume302 includes contributions from both the cavity andtubing109 traveling from the cavity to the fuel processor.
• Reserve volume302 may also comprise a bladder that conforms in size and shape to the volume offuel source17 contained therein. A rubber sac or foldable bellows similar to those described above may be suitable. In one embodiment,tube109 collapses on itself whenmating connector140 andconnector140 are separated. This sealstube109 and prevent escape of anyfuel source17 contained therein.
• While this invention has been described in terms of several preferred embodiments, there are alterations, permutations, and equivalents that fall within the scope of this invention which have been omitted for brevity's sake. For example, although the present invention has been described with respect to separatemain controller210 and fuelcell system controller214, it is understood that these two functional elements may be combined into a common controller. In addition, while the present invention has been described with respect to reformed methanol fuel cell systems that include a fuel processor to convert the fuel source to hydrogen before receipt by the fuel cell, storage devices described herein are also useful for direct fuel source systems such as direct methanol fuel cell systems. In a direct fuel source system, the storage device provides the fuel source directly to the fuel cell without conversion to hydrogen by a separate fuel processor. While not described in detail, such digital control of a mechanical system is well known to one of skill in the art. It is therefore intended that the scope of the invention should be determined with reference to the appended claims.

Claims (27)

1. A fuel cell system for producing electrical energy, the fuel cell system comprising:

a portable hydrogen fuel source cartridge for storing a hydrogen fuel source, the storage device including a) a bladder that contains the hydrogen fuel source, b) a housing that provides mechanical protection for the bladder, c) a memory that stores information relevant to usage of the cartridge, and d) a connector that interfaces with a mating connector to permit transfer of the hydrogen fuel source between the bladder and a device that includes the mating connector;

a fuel processor configured to receive the hydrogen fuel source and to output hydrogen;

a fuel cell configured to produce electrical energy using hydrogen output by the fuel processor; and

a controller configured to communicate with the memory on the cartridge.

2. The fuel cell system ofclaim 1 wherein the controller is configured to read the information from the memory.

3. The fuel cell system ofclaim 1 wherein the controller is configured to write the information to the memory.

4. The fuel cell system ofclaim 1 wherein the controller is configured to estimate a remaining volume in the cartridge.

5. The fuel cell system ofclaim 4 wherein the controller is configured to compare fuel flow since filling of the cartridge against a volume read from the cartridge.

6. The fuel cell system ofclaim 4 wherein the controller is configured to write the remaining volume into memory.

7. The fuel cell system ofclaim 1 wherein the controller, fuel processor and fuel cell are incorporated into a portable electronics device.

8. The fuel cell system ofclaim 7 wherein the cartridge is external to the electronics device when providing the hydrogen fuel source to the fuel processor.

9. The fuel cell system ofclaim 8 wherein the electronics device further includes an external mounting bracket that couples the cartridge to the electronics device.

10. The fuel cell system ofclaim 1 wherein the information relevant to usage of the cartridge comprises one of: a fuel volume, a fuel composition, an identification, and a number of refills.

11. The fuel cell system ofclaim 1 wherein the information relevant to usage of the cartridge comprises one of: a model number for the cartridge, a volume capacity for the cartridge, and a current volume for the cartridge.

12. The fuel cell system ofclaim 1 wherein the bladder includes a maximum volume between about 20 milliliters and about 400 milliliters.

13. The fuel cell system ofclaim 1 wherein the memory comprises a digital memory and the cartridge further includes a wireless communication device that permits wireless communication with a wireless interrogator associated with the controller.

14. The fuel cell system ofclaim 13 wherein the wireless communication device interrogator provides power to the wireless communication device.

15. The fuel cell system ofclaim 1 further comprising a sensor that monitors a condition related to the health or functioning of the cartridge.

16. A fuel cell system for producing electrical energy, the fuel cell system comprising:

a portable hydrogen fuel source cartridge configured to store a hydrogen fuel source, the cartridge including a memory that stores information relevant to usage of the cartridge and a connector that interfaces with a mating connector to permit transfer of the hydrogen fuel source between the bladder and a device that includes the mating connector;

an electronics device including

a controller that communicates with the memory on the storage device,

a fuel processor that includes i) a reformer configured to receive the hydrogen fuel source and configured to output hydrogen, and ii) a burner configured to provide heat to the reformer, and

a fuel cell configured to produce electrical energy using hydrogen output by the fuel processor.

17. The fuel cell system ofclaim 16 wherein the cartridge is external to the electronics device when providing the hydrogen fuel source to the fuel processor.

18. The fuel cell system ofclaim 17 wherein the electronics device further includes an external mounting bracket that couples the cartridge to the electronics device.

19. The fuel cell system ofclaim 16 wherein the information relevant to usage of the cartridge comprises one of: a model number for the cartridge, a volume capacity for the cartridge, and a current volume for the cartridge.

20. A method for using a cartridge that includes a hydrogen fuel source, the method comprising:

transferring the hydrogen fuel source between the cartridge and a mating connector that interfaces with a connector included in the cartridge;

reading a volume for the hydrogen fuel source from a memory that is included with the cartridge and configured to store information relevant to usage of the cartridge; and

writing a current volume for the hydrogen fuel source to the memory.

21. The method ofclaim 20 further comprising writing, to the memory, a usage history according to an identification for the cartridge.

22. The method ofclaim 20 wherein reading the current hydrogen fuel source volume includes reading a volume capacity for the cartridge.

23. The method ofclaim 20 further comprising converting the current hydrogen fuel source volume to an available run time for an electronics device that reads from the memory.

24. The method ofclaim 20 wherein the mating connector is included in a fuel cell system including a fuel cell that is configured to produce electrical energy.

25. The method ofclaim 24 wherein the fuel cell system includes a fuel processor configured to receive the hydrogen fuel source and to output hydrogen to the fuel cell.

26. The method ofclaim 20 further comprising reading, from the memory, one of: a fuel type, a fuel composition, an identification signature, a model number for the storage device, and a number of refills.

27. The method ofclaim 20 further comprising writing, to the memory, one of: a number of refills provided to the cartridge, a fill or refill date, and a refilling service provider that refilled cartridge.

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