Modular system for hydrogen generation and method of operating the same

Abstract

The modular system for hydrogen generation includes a plurality of cores and a hub. Each core includes an electrolyzer and a power supply. The power supply is operable to manage power to the core's electrolyzer and is redundant to the power supply of at least one other of the plurality of cores. The hub includes a water module, a heat exchange module, and a switchgear module. The water module includes a water source in fluid communication with the electrolyzer of each of the plurality of cores, the heat exchange module includes a heat exchanger in thermal communication with the electrolyzer of each of the plurality of cores, and the switchgear module includes a switch activatable to electrically isolate the power supply of each of the plurality of cores.

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims the benefit of U.S. Provisional Patent Application No. 62 / 938,511, filed on November 21, 2019, the entire content of which is incorporated herein by reference.

[0002] The present disclosure generally relates to chemical production, and more specifically, to modular systems for hydrogen generation.

Background Art

[0003] Hydrogen is a common gas with many uses such as petroleum refining, metal processing, food processing, and ammonia production. For industrial applications, hydrogen is generally formed from non - renewable energy sources, particularly methane. However, due to its combustion in air, hydrogen is difficult to store and ship. Thus, hydrogen is generally used at or near its production facility and is thus limited by the local availability of non - renewable energy sources.

Summary of the Invention

Means for Solving the Problems

[0004] According to one embodiment, a modular system for hydrogen generation includes a plurality of cores and a hub. Each core includes an electrolytic cell and a power supply unit. The power supply unit is operable to manage power to the electrolytic cell of the core and is redundant with respect to at least another one of the power supply units of the plurality of cores. The hub includes a water module, a heat exchange module, and a switch module. The water module includes a water source that is in fluid communication with the electrolytic cell of each of the plurality of cores, the heat exchange module includes a heat exchanger that is in thermal communication with the electrolytic cell of each of the plurality of cores, and the switch module includes switches that can be activated to electrically isolate the power supply units of each of the plurality of cores.

[0005] According to another embodiment, a method of controlling a modular system for hydrogen generation includes monitoring an individual hydrogen production capacity of each of a plurality of cores, each core including an electrolyzer and a power supply that are in electrical communication with each other; assessing energy available to the plurality of cores from one or more power sources; setting an individual operating set point for each core within the plurality of cores such that the plurality of cores collectively meet a predetermined performance goal, based on the hydrogen production capacity of each core and the energy available from one or more power sources; and directing energy available from one or more power sources to the plurality of cores according to the individual operating set points of each core. The present invention provides, for example, the following. (Item 1) A modular system for hydrogen generation, comprising a plurality of cores, each core including an electrolytic cell and a power supply unit, the power supply unit being operable to manage power to the electrolytic cell of the core and being redundant with respect to at least another one of the plurality of cores' power supply units, a plurality of cores, a hub, the hub including a water module, a heat exchange module, and a switch module, the water module including a water source in fluid communication with the electrolytic cell of each of the plurality of cores, the heat exchange module including a heat exchanger in thermal communication with the electrolytic cell of each of the plurality of cores, the switch module including a switch activatable to electrically isolate the power supply unit of each of the plurality of cores, a hub and a modular system. (Item 2) The power supply unit of each core is hot-swappable while the individual electrolytic cell of the core is in operation, according to the modular system of Item 1. (Item 3) Each power supply unit is in thermal communication with the heat exchange module via coolant fluidity between each power supply unit and the heat exchange module, according to the modular system of Item 1. (Item 4) Each power supply unit is connected to both a DC power source and an AC power source, and each power supply unit is configured to provide DC power to the electrolytic cell of the core, according to the modular system of Item 1. (Item 5) Each power supply unit is configured to provide a first DC voltage to the electrolytic cell of the core and a second DC voltage lower than the first DC voltage to an auxiliary device of the core, according to the modular system of Item 1. (Item 6) Each core further includes an auxiliary power source in electrical communication with the individual electrolytic cell of a given core, according to the modular system of Item 1. (Item 7) The electrolytic cell includes an electrochemical stack, water from the water module is receivable into the electrochemical stack, and the electrochemical stack is configured to receive power from the power supply unit and generate hydrogen and oxygen from the water, according to the modular system of Item 1. (Item 8) The electrochemical stack comprises a proton exchange membrane stack, a solid oxide electrolysis stack, an alkaline cell stack, or a combination thereof, according to the modular system of Item 7. (Item 9) The hub further A compression module including an electrolytic cell in fluid communication with each core and a compressor for receiving hydrogen that can be formed by the plurality of cores. A storage module in fluid communication with the compression module, wherein the hydrogen compressed by the compressor is movable into the storage module. The modular system according to item 1, comprising the above. (Item 10) The modular system according to item 1, wherein the heat exchange module includes a heat loop, and the heat exchanger is in thermal communication with each core via the heat loop. (Item 11) The modular system according to item 1, wherein the heat exchanger and the heat loop form at least a part of a heat pump operable to convert waste heat from the plurality of cores into heat that can be delivered to one or more other parts of the hub. (Item 12) A method for controlling a modular system for hydrogen generation, comprising: Monitoring the individual hydrogen production capacity of each of the plurality of cores, each core including an electrolytic cell and a power supply that are in electrical communication with each other; Assessing the energy available to the plurality of cores from one or more power sources; Based on the hydrogen production capacity of each core and the energy available from the one or more power sources, setting individual operating set points for each core within the plurality of cores such that the plurality of cores collectively meet a predetermined performance goal; Directing the available energy from the one or more power sources to the plurality of cores according to the individual operating set points of each core. The method comprising the above. (Item 13) The method according to item 12, wherein the predetermined performance goal includes maximizing hydrogen output using all of the available energy when the available energy is less than the energy required to meet the hydrogen output demand from the hardware downstream of the plurality of cores. (Item 14) Setting the individual operating set points for each core within the plurality of cores includes adding additional cores to the plurality of cores. The predetermined performance goal includes a substantially constant voltage across the plurality of cores during full power operation. The method according to item 12. (Item 15) If the individual hydrogen production capacity of one of the cores within the plurality of cores is less than the rated hydrogen output for the individual core, setting the individual operating set points of each core within the plurality of cores includes setting the operating set points of at least one other core within the plurality of cores above the rated hydrogen output for the at least one other core, the method according to item 12. (Item 16) The electrolyzer of each core includes an individual electrochemical stack, Monitoring the individual hydrogen production capacity of each core includes transmitting a signal to the power supply of the individual core, transmitting a current interruption or ripple function to the electrochemical stack, and receiving a current interruption impedance measurement of the electrochemical stack in response to the current interruption or ripple function, the method according to item 12. The method according to item 12. (Item 17) Monitoring the individual hydrogen production capacity of each core includes detecting the power available to the individual electrolyzer of each core, the method according to item 12. (Item 18) Assessing the power available to the plurality of cores from the one or more power sources includes determining the amount of power available from an intermittent power source, the method according to item 12. (Item 19) The predetermined performance target includes an equilibrium between the total power collectively required for the operating set points of the plurality of cores and the amount of power available from the intermittent power source, the method according to item 18. (Item 20) The predetermined performance target includes maximum power point tracking of the intermittent power source such that the total power collectively required for the operating set points of the plurality of cores corresponds to the maximum available power from the intermittent power source without requiring excess power from other sources, the method according to item 18.

Brief Description of the Drawings

[0006]

Figure 1A

[0007]

Figure 1B

[0008]

Figure 2A

Figure 2B

Figure 2C

[0009] Like reference symbols in the various drawings indicate like elements.

Best Mode for Carrying Out the Invention

[0010] Detailed Description The embodiments will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments are shown. However, the foregoing may be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. All fluid flows may flow through conduits (e.g., pipes and / or manifolds) unless otherwise defined.

[0011] All documents mentioned in this specification are hereby incorporated by reference in their entirety. References to items in the singular should be understood to include items in the plural unless explicitly stated otherwise or clear from the context, and vice versa. Grammatical connectives are intended to represent all disjunctive and conjunctive combinations of clauses, sentences, words, and equivalents, unless stated otherwise or clear from the context. Accordingly, the term "or" should generally be understood to mean "and / or," and the term "and" should generally be understood to mean "and / or."

[0012] The recitation of ranges of values herein is not intended to be limiting; rather, each individual value falling within the range is, unless otherwise indicated herein, individually incorporated herein as if it were specifically recited herein. The words "about," "approximately," or the like, when accompanying a numerical value, should be construed to include any deviation that would be understood by one of ordinary skill in the art for the intended purpose. Values and / or ranges of values are provided herein only as examples and do not constitute limitations on the scope of the described embodiments. The use of any example or exemplary language (e.g., "such as," "etc.," or the like) is merely intended to clarify the embodiments and does not impose a limitation on the scope of the embodiments. No language in this specification should be construed as indicating any non-claimed element as essential to the practice of the disclosed embodiments.

[0013] Installing the hydrogen production location at the same location as its final industrial use destination can present its own challenges related to cost, safety, and throughput. Therefore, there remains a need for hydrogen generation that can be implemented cost-effectively within a factory that can accommodate safe implementation while meeting the requirements of downstream applications, including facilities within resource-constrained areas, and providing a robust throughput. In the following description, various aspects of the hydrogen generation system and method of operation are described in the context of electrolyzers that are arranged within a core (i.e., for example, a facility) that receives power redundancy, shares connections with a modular hub, and provides water and electricity to the core while receiving outputs of hydrogen, oxygen, and heat. This configuration facilitates cost-effective scaling of hydrogen from electrolysis while achieving a throughput suitable for industrial demand and providing robustness against resource availability and equipment failure and / or degradation.

[0014] As used herein, the term "module" and variations thereof are understood to include discrete units (e.g., housed within a cabinet or other similarly enclosed structure) that, as necessary, can be connected (e.g., via external or otherwise readily accessible connectors) while being in electrical communication, fluid communication, and / or thermal communication with one or more other elements within a system, and that provide an overall functional aspect of operating and / or maintaining a system for generating hydrogen. Thus, for example, each module may be interchangeable, at least through disconnection of one or more electrical connections, fluid connections, or thermal connections only, and in some cases, through re - establishment of individual connections to another instance of the same type of module. These connections may include connections that are at least standardized between modules of the same type, reducing the amount of time and training required to change a module. Further, or alternatively, each module may have a form factor adaptable for portability within a factory (e.g., by forklift or cart). Thus, for example, a water module is understood to include connectors that can be fixedly attached in fluid communication with each other and with a water source (e.g., a source outside the factory), and pumps and filters in fluid communication with a plurality of electrolyzers such that equipment within the water module can disperse water between the plurality of electrolyzers.

[0015] Further, or alternatively, unless otherwise specified or not apparent from the context, each of the modules described herein may exist redundantly, reducing the likelihood of an unexpected interruption resulting from a device failure within one module. In this context, redundancy is understood to include multiple instances of the same type of module and / or the presence of auxiliary sources of electrical communication, fluid communication, and / or thermal communication provided by a given module. However, for purposes of clarity of illustration and explanation, redundancy in the form of multiple instances of a given type of hub module is generally not shown. Redundancy in the form of auxiliary equipment is shown to the extent that it is beneficial in explaining an aspect of the present system.

[0016] Generally, unless stated otherwise or not apparent from the context, each instance of a given type of core and / or module may be interchangeable with another instance of the same type of module without an unexpected interruption in the overall system's hydrogen production. Further, or alternatively, in the case of degradation or failure of a given type of core or module, auxiliary functionality is provided by one or more other elements of the system and may reduce or eliminate the degraded performance of the system during the intervals between the scheduled interruptions in hydrogen production by the system. However, it should be understood that the term "uninterrupted" is understood in the context of foreseeable failures and / or degradation of equipment and may not include unforeseen or catastrophic events. Thus, in one embodiment, the overall performance of the system (i.e., hydrogen generation) may be uninterrupted. This is significant for achieving robustness in meeting industrially-scaled production volumes useful for achieving cost effectiveness in hydrogen production and / or one or more downstream applications such as ammonia synthesis from hydrogen or the use of hydrogen within chemical or semiconductor device manufacturing facilities. That is, the downtime of the system is generally associated with the operation of the system such that it is not offset by the cost, i.e., the cost of the equipment, and the corresponding production of hydrogen. Thus, modularity of the system can contribute to the cost effectiveness of a given hydrogen production technique when promoting uninterrupted production of hydrogen.

[0017] As used herein, the term "use" includes any one or more of the various different downstream uses of hydrogen, oxygen, and / or heat formed by the system, and is thus understood to include such local uses of hydrogen, oxygen, and / or heat within a plant located at the same site. For example, any one or more of the various different systems and methods described herein may be used to generate hydrogen, oxygen, and / or heat for a use, including ammonia synthesis. As a more specific example, a use within the context of the present disclosure is understood to be part of any one or more of the various systems and methods described in a U.S. patent application by Ballantine, et al., filed on the same day as this specification and having Attorney Docket No. 35055-001US, entitled "SYSTEMS AND METHODS OF AMMONIA SYNTHESIS" (the entire contents of each of these references are incorporated herein by reference), including ammonia synthesis.

[0018] Referring now to FIGS. 1A and 1B, a system 100 for generating hydrogen may include a plurality of cores 102a, b, c (e.g., collectively, a plurality of cores 102a, b, c; individually, core 102a, core 102b, and core 102c, a core module), a hub (e.g., a facility module) 104, and a wall 105 (e.g., a fire-rated structure) that partitions at least a portion of the hub 104 in which pressurized hydrogen is stored or processed from the remainder of the hub 104 and the plurality of cores 102a, b, c, providing protection from inadvertent conditions that could cause a fire and / or explosion. The plurality of cores 102a, b, c are shown and discussed herein as including three cores, but this is for purposes of clear and efficient illustration, and it should be understood that any number of cores may be used without departing from the scope of the present disclosure. The plurality of cores 102a, b, c may be in electrical communication, fluid communication, and thermal communication with the hub 104 such that the hub 104 can serve as a centralized resource for distributing electricity, water, and / or cooling individually to the cores 102a, b, c and collecting hydrogen, oxygen, and / or heat produced by the cores 102a, b, c individually. For example, each of the cores 102a, 102b, and 102c may include an individual instance of a power supply 106 and an electrolyzer 108 that are in electrical communication with each other. The hub 104 may include a switchgear module 110, a water module 112, a heat exchange module 114, a compression module 116, and a storage module 118. The power supply 106 for each of the plurality of cores 102a, b, c may be in electrical communication with a power source 120 via the switchgear module 110 of the hub 104 and receive electricity as an input for the electrolysis of hydrogen. The switchgear module 110 may include a transformer, a circuit breaker, a switch, or any one or more of other hardware useful for interrupting power to each of the power supplies 106 of the plurality of cores 102a, b, c and protecting the equipment of each of the cores 102a, 102b, and 102c, and in some instances, the components of the hub 104 from abnormalities (e.g., surges) in the power supplied from the power source 120.The electrolyzer 108 for each of the plurality of cores 102a, b, c may be in fluid communication with the water module 112 of the hub 104 and receive water as an input for the electrolysis of hydrogen. At least the electrolyzer 108 for each of the plurality of cores 102a, b, c may receive cooling (e.g., a heat transfer medium, e.g., a cooling liquid such as ethylene glycol, propylene glycol, or cooling water) from the heat exchange module 114 and maintain it at a temperature suitable for the electrolysis of hydrogen (e.g., greater than about 0 °C and less than about 100 °C). Further, the hydrogen output of the plurality of cores 102a, b, c may be in fluid communication with one or more hydrogen handling modules of the hub 104 that can be separated from the rest of the system 100 by the wall 105. As an example, the electrolyzer 108 for each of the plurality of cores 102a, b, c may be in fluid communication with a compression module 116 to compress hydrogen, which may, in addition or alternatively, be in fluid communication with a storage module 118 for storing hydrogen for future use. Such a unification of the functions of the hub 104 may be useful, among other things, to provide a regulated input for electrolysis and achieve economies of scale in sizing the various aspects of the hub 104, which will be described in more detail below.

[0019] In use, and as described below, the system 100 may also include a certain redundancy that is useful for reducing the likelihood of an unexpected interruption that could otherwise occur from combining a plurality of electrolyzers together and forming hydrogen from electrolysis on an industrial scale. For example, the power supply 106 for each of the plurality of cores 102a, b, c may be redundant with respect to at least another one of the plurality of cores 102a, b, c. As a more specific example, the power supply 106 of core 102a may be in further electrical communication with the electrolyzer 108 of core 102b such that the power supply 106 of core 102a can provide power to the electrolyzer 108 of core 102b in the event of a failure of the power supply 106 of core 102b. The system 100 may include similar redundancy for cores 102a and 102c.

[0020] In addition to the uninterrupted operation facilitated by the redundancy for the supply of any one or more of the various different regulated inputs from the power and / or hub 104, the cost-effective operation of the system 100 can be the function of the power source 120 that provides electricity to each instance of the electrolyzer 108. For example, the power source 120 may advantageously include multiple types of generators that can be operated in parallel and / or individually at different times. For example, in one deployment, the power source 120 may include a power grid, and it may be useful to switch to a local power source at a location where the power grid is reliable and utilize lower-cost electricity. Examples of such local sources include, but are not limited to, a diesel generator, a natural gas-fired generator, a biogas such as a generator powered by a biofuel source, an ethanol-fired generator, a gasoline-fired generator, a propane-fired generator, a photovoltaic array, a wind turbine (e.g., one or more wind turbines), a hydroelectric generator or turbine (e.g., tidal or dam type), a geothermal generator, a thermoelectric generator, a heat engine (e.g., a turbine, a piston engine, or other engine that uses heat and / or fuel as an input), or one or more fuel cell generators.

[0021] As can be understood from these foregoing embodiments, the power supply 120 may include a local source that is nominally continuous and / or intermittent. Thus, when intermittent electricity from a local source such as a photovoltaic array is available, the power supply 120 may preferentially be the local source when power from the local source is available, without requiring separate storage. Additionally, or alternatively, the system 100 may store excess power from the local source when it is available (e.g., during the day from a photovoltaic array), and then release it to the plurality of cores 102a, b, c to manage fluctuations in power from one or more intermittent power sources, such that it may be useful to be in electrical communication (e.g., via the power supply unit 106) with at least each instance of the electrolytic cell 108 of the plurality of cores 102a, b, c, and may include a battery 121. As another example, in some locations, the power grid may be unreliable or non-existent such that the power supply 120 includes any one or more than one of various different local sources such as those listed above, primarily or exclusively.

[0022] As can be understood from both the presence and absence of the advantages of a reliable power transmission network in the foregoing scenario, the power supply unit 106 may adjust and control electricity in any one or more of various different AC power or DC power formats that can be received from the power source 120. Generally, therefore, the power supply unit 106 includes the circuit network 126 and converts the electric current from the power source 120 into a power format (current, voltage, and frequency) that can be used to supply power to the load of the electrolytic cell 108 of the individual ones of the cores 102a, 102b, or 102c, with respect to which the power supply unit 106 is the primary power source. The circuit network 126 may include, for example, any one or more of various different rectifiers and / or transformers useful for changing the power format according to any one or more of various different well-known techniques. That is, in one form, the circuit network 126 may receive electricity from the power source 120 and convert the form of this electricity into another form that is suitable for use by one of the electrolytic cells 108 of the cores 102a, 102b, or 102c.

[0023] In the case where the electrolytic cell 108 starts based on DC power and the power source 120 (for example, a power transmission network or a diesel generator) provides AC power, the circuit network 126 may include an inverter that converts AC power into DC power and a DC / DC converter that controls the flow of the rectified DC power to the electrolytic cell 108. As an example, the circuit network 126 may receive AC power from an electric power company or a wind turbine, such as a transformer (for example, a step-up, step-down, zigzag, or other isolation-generating transformer) or an AC connection to an inverter output or a rotating generator output. As an example, the circuit network 126 may produce DC power from a rectifier / inverter supplied by an AC power supply unit. Additionally, or alternatively, the circuit network 126 may produce multi-polar DC power, such as a bipolar arrangement of approximately -400V DC, neutral, and +400V DC.

[0024] In one example, the power supply unit 106 may be connected to an AC power company source and / or one or more other AC sources (e.g., generators, wind power generation, etc.) with only one power processing stage. The single power processing stage may be, for example, a single-phase pulse width modulation or a power factor correction circuit. Additionally, or alternatively, the single power processing stage may be a three-phase pulse width modulation or a power factor correction circuit (e.g., Vienna rectifier) that supplies power to one electrolyzer stack, a full bridge without a neutral connection, or a full bridge with a neutral connection for supplying power to multiple electrolyzer stacks.

[0025] Additionally, or alternatively, the power grid 126 may include fault protection such as fuse blowing or short circuit sensing to facilitate the safe and reliable operation of the power supply unit 106. In one example, the power supply unit 106 may provide 400V DC (full rated power) to the electrolyzer 108. Further, or instead, the power supply unit 106 may provide two different types of power to the same instance of the electrolyzer 108 that may be useful for powering auxiliary devices associated with the operation, monitoring, and / or safety of the electrolyzer 108. For example, each power supply unit 106 may be configured to provide a first DC voltage to the electrolyzer 108 of the core 102 and a second DC voltage lower than the first DC voltage to the auxiliary devices of the core 102. Thus, returning to the 400V DC example, the power supply unit 106 provides 400V DC to a part of the electrolyzer 108 (e.g., an electrochemical stack described in more detail below), while providing 24V DC to the auxiliary devices (e.g., valves or blowers) of the core 102 and / or sensor wiring for safety logic. As another example, the power supply unit 106 may use an isolated DC / DC to provide split DC to a part of the electrolyzer 108.

[0026] Electrolyzer 108 starts up based on DC power, and in an example, power source 120 (e.g., a photovoltaic array) or battery 121 provides DC power. Thus, the inverter / rectifier may be bypassed, and the DC power may be provided directly from the DC power source or battery to the DC / DC converter of circuit network 126 and then to electrolyzer 108. Thus, circuit network 126 is configured to operate electrolyzer 108 from both AC and DC power by rectifying AC power to DC power using an AC / DC inverter based on AC power from an AC power source, based on DC power from a DC power source, or simultaneously, and then controlling the magnitude of the DC power provided to electrolyzer 108 using a DC / DC converter.

[0027] Further, or alternatively, power supply unit 106 may be sized to power the load of electrolyzer 108 corresponding to at least one other of the plurality of cores 102a, b, c for which power supply unit 106 provides redundancy. For clarity and efficiency, the following description assumes that each electrolyzer 108 within the plurality of cores 102a, b, c operates at the same nominal voltage and current. In practice, such uniformity across instances of electrolyzer 108 may facilitate achieving redundancy using an efficient hardware configuration. However, unless otherwise specified or apparent from the context, it should be understood that some instances of electrolyzer 108 may operate at voltages and frequencies different from one or more other instances of electrolyzer 108 without departing from the scope of the present disclosure.

[0028] In one example, the power supply unit 106 may be hot swappable during operation of an individual instance of the electrolyzer 108 of core 102a, core 102b, or core 102c, more specifically, while using electricity to generate hydrogen from the electrolysis of water. Here, it should be understood that such hot swapping of the power supply unit 106 can be facilitated by the redundancy provided by instances of the power supply unit 106 that are not being hot swapped. That is, while one instance of the power supply unit 106 is being replaced, one or more other instances of the power supply unit 106 may provide power to an instance of the electrolyzer 108 that would otherwise receive power from the instance of the power supply unit 106 being replaced. As can be understood from the foregoing embodiments, thus, the redundancy provided by instances of the power supply unit 106 within the plurality of cores 102a, b, c facilitates the maintenance and / or repair of each instance of the power supply unit 106 without interruption of hydrogen production.

[0029] Generally, electrolyzer 108 may include an electrochemical stack 128, in which electricity may be directed to form hydrogen and oxygen from water using electrolysis. More specifically, the electrochemical stack 128 may receive water from the water module 112, and the electrochemical stack 128 may be activatable through the power from the power supply 106, direct at least a portion of the power from the power supply 106, electrolyze the water within the electrochemical stack 128, and form hydrogen and oxygen. Examples of the electrochemical stack 128 include, but are not limited to, proton exchange membrane (PEM) stacks, solid oxide electrolysis cells, alkaline cells, or combinations thereof. In a PEM electrolyzer cell, water is provided on the anode electrode side of the membrane (i.e., electrolyte), and under an applied current or voltage provided between the anode and cathode electrodes, hydrogen diffuses from the anode electrode side of the membrane to the cathode electrode side, generating hydrogen products. Oxygen and excess water are output from the anode electrode side of the PEM electrolyzer cell. As a more specific example, the electrolyzer 108 may include any one or more than one of the various different aspects of the devices and systems described in the U.S. patent application by Ballantine, et al., filed on the same date as this specification and having Attorney Docket No. 35055-002US, entitled "ELECTROCHEMICAL DEVICES, MODULES, AND SYSTEMS FOR HYDROGEN GENERATION AND METHODS OF OPERATING THEREOF" (the entire contents of each of these references are incorporated herein by reference).

[0030] In addition to producing hydrogen, the electrochemical stack 128 may also produce oxygen and heat. One or both of these may have independent value. For example, the oxygen from the electrochemical stack 128 may be collected and used in one or more other local or distributed applications into which the oxygen is input. Additionally, or alternatively, the heat removed from the electrochemical stack 128 may be used locally, for example, to improve the efficiency on one or more aspects of the system 100. For example, as described in more detail below, the heat recovered from the electrochemical stack 128 may, in some cases, be used to generate electricity.

[0031] In some implementations, each of the plurality of cores 102a, b, c may further include an auxiliary power source 123 that is in electrical communication with an individual instance of the electrolyzer 108 of a given core. The auxiliary power source 123 may provide power to the electrolyzer 108 during startup, shutdown, and / or standby mode. Further, or alternatively, the auxiliary power source 123 may provide power to the electrolyzer 108 in the case where the power source 120 is interrupted, and the auxiliary power source 123 may be sized, in some cases, to enable a safe shutdown or, in other cases, to enable continued operation of the electrolyzer. As an example, the auxiliary power source 123 may include a battery. As another example, the auxiliary power source 123 may include a fuel cell in fluid communication with the storage module 118 and may receive hydrogen used to power the fuel cell. Continuing with the example of the auxiliary power source 123 that includes a fuel cell, the fuel cell and the corresponding electrolyzer may share the factory and / or the rest of the power conditioning system. The auxiliary power source 123 may be electrically connected to a power bus that electrically connects the power source 120 to the individual power supplies 106, and / or, as shown in FIG. 1B, to a power bus (such as a DC power bus) that electrically connects the power supplies 106 to individual electrolyzers 108 within the same core 102.

[0032] Generally, the heat exchange module 114 may include a heat exchanger 130 sized to remove heat from at least a subset of the plurality of cores 102a, b, c. Assuming the heat exchange module 114 is modular, additional instances of the heat exchange module 114 may be added to the system 100 as discussed in more detail below, such that one additional instance of the plurality of cores 102a, b, c adapts to increased hydrogen demand or compensates for the degraded performance over time of any one or more of the plurality of cores 102a, b, c. Further, or alternatively, in the context of the heat exchange module 114, redundancy may include full redundancy in the case of a catastrophic failure of an instance of the heat exchange module 114. In one instance, redundancy in the heat exchange context may include additional heat removal capacity and may account for transient operation.

[0033] In some cases, the heat exchange module 114 may further include the heat loop 132 shown in FIG. 1A. For example, the heat exchanger 130 may be in thermal communication with each of the plurality of cores 102a, b, c via the heat loop 132. As a more specific example, the heat exchanger 130 may include a reservoir of a cooling fluid (e.g., glycol or water), and the cooling fluid may move through the heat loop 132, pass across the plurality of cores 102a, b, c, and remove heat (or add heat in the case of startup under certain conditions) during steady-state operation. This type of heat exchanger may be particularly useful for providing a large amount of cooling capacity in a small footprint, especially as compared to an air heat exchanger. Further, or alternatively, liquid heat exchange may be useful for controlling the temperature of the plurality of cores 102a, b, c in the case of variations in the ambient environment surrounding the system 100.

[0034] In one implementation, the heat exchange module 114 may convert low-quality heat from the plurality of cores 102a, b, c into higher-quality heat that can be delivered to one or more other parts of the system 100, such as the hub 104. For example, the heat exchanger 130 and the heat loop 132 may move waste heat from the plurality of cores 102a, b, c, via the heat loop 132, between the plurality of cores 102a, b, c and the heat exchanger 130 (e.g., under the force of a compressor), and may form at least part of a heat pump operable to convert it into higher-quality heat as a working fluid (e.g., a refrigerant). At least partially, the higher-quality heat captured by the heat pump formed by the heat exchanger 130 and the heat loop 132 may be directed, for example, to the storage module 118, and may reduce the likelihood of freezing of the conduits and / or valves of the storage module 118 as the hydrogen expands in response to release.

[0035] Advantageously, the heat exchange module 114 may capture heat for use in other parts of the system, although other uses of the captured heat are also, additionally, or alternatively, conceivable. For example, the heat exchange module 114 may direct waste heat (e.g., at about 70° C.) from the plurality of cores 102a, b, c towards ground source cooling in an organic Rankine cycle to generate electricity for use by the system 100, and thus increase overall efficiency. Such electricity generation may further, or alternatively, contribute to providing uninterrupted power to the plurality of cores 102a, b, c by providing an energy time shift.

[0036] In one case, the waste heat removed by the heat exchange module 114 may be used to improve the efficiency of the water module 112. For example, the waste heat removed by the heat exchange module 114 may drive a water capture subsystem within the water module 112 to remove moisture from the air, and thus may be used to reduce the overall water requirements of the system 100. As another example, the waste heat removed by the heat exchange module 114 may be used to drive a water purification process within the water module 112.

[0037] The heat exchange module 114 can generally manage the temperature of each instance of the electrolyzer 108, but it should be understood that other heat transfer schemes can also be used, in addition to or as an alternative, to manage the heat within the plurality of cores 102a, b, c. For example, in some instances, the power supply 106 includes a cooling fan or blower to provide flowable cooling across individual instances of the electrolyzer 108 within the same one of the core 102a, core 102b, or core 102c, and may remove heat from the electrolyzer 108. This can be useful, for example, when the power supply 106 does not provide cooling to facilitate rapid heating of the electrolyzer 108 in response to startup. As another example, the heat exchanger 130 of the heat exchange module 114 may be in thermal communication with each instance of the power supply 106 such that the heat exchange module 114 can remove heat from both the power supply 106 and the electrolyzer 108 of a given one of the core 102a, core 102b, or core 102c.

[0038] Generally, the compression module 116 includes a compressor 134 that is in fluid communication with each instance of the electrolyzer 108 of the plurality of cores 102a, b, c and may receive the hydrogen produced. The compressor 134 may, in turn, compress the hydrogen for storage within the storage module 118. Assuming that the compression of hydrogen produces heat, the heat from the compression of hydrogen within the compression module 116 is advantageously captured and can be used at any location within the system 100. Thus, for example, the compression module 116 may be in thermal communication with the heat exchange module 114 such that the heat from the compression module 116 can be converted to higher quality heat, converted to electricity, and / or directed to one or more other parts of the system 100 according to any one or more than one of the techniques described herein.

[0039] The hub 104 has been described as including certain modules, but it should be understood that additional or alternative modules are also conceivable. For example, in some cases, the hub 104 includes a remote measurement module 136 that is in electrical communication with a plurality of cores 102a, b, c and may receive information related to the performance of the plurality of cores 102a, b, c. Further, or alternatively, the hub 104 includes a dispensing module 139 that is in fluid communication with one or more than one of a compression module 116 or a storage module 118 and may control the dispensing of hydrogen in accordance with downstream demand.

[0040] As another example, the hub 104 may additionally or alternatively include an application module 138 that utilizes the hydrogen produced by the system 100 downstream. For example, the application module 138 may be a combustion power plant. In such cases, the application module 138 may utilize oxygen such as that produced as a reaction byproduct in the generation of hydrogen from the electrolysis of water (e.g., in an oxy-fuel combustion process for producing CO2-separable carbon and lower-level NO x . Additionally or alternatively, the application module 138 may be a steel production plant that may use hydrogen for steel production and oxygen for steel welding or cutting. In some cases, the application module 138 may include one or more than one of a semiconductor device foundry or a chemical plant that produces semiconductor devices or chemicals, respectively, using hydrogen.

[0041] As yet another example, the hub 104 may include a nitrogen module 140 that produces nitrogen (e.g., from air) and may direct the nitrogen to each instance of the electrolyzers 108 of the plurality of cores 102a, b, c.

[0042] As yet another example shown in FIG. 1B, the hub 104 may include a controller 142 that includes a processing unit 144 and a non-transitory computer-readable storage medium 146 having computer-readable instructions stored thereon for causing the processing unit 144 to perform any one or more of the various different control techniques described herein. In one embodiment, the firmware of the processing unit 144 involved in safe operation and the state machine of the processing unit 144 are split from the operation script for the system, allowing only the flash of the control script logic without affecting the safety logic or the state machine logic. The system 100 can operate even in the presence of a system failure.

[0043] Referring now to FIG. 2A, an exemplary method 200 for controlling a modular system for hydrogen generation may be implemented using any one or more of the various different aspects of the system described herein. Thus, for example, the exemplary method 200 may be implemented using the system 100. More specifically, unless otherwise specified or apparent from the context, the exemplary method 200 is understood to be executable by the processing unit 144 in accordance with computer-readable instructions stored on the non-transitory computer-readable storage medium of the controller 142 (shown in FIG. 1B).

[0044] As shown in step 202, the exemplary method 200 may include monitoring the individual hydrogen production capacity of each of a plurality of cores. Each core may be any one or more than one of the various different cores described herein, and thus may include an electrolyzer and a power supply unit that are in electrical communication with each other. The step of monitoring the individual hydrogen production capacity of each core may include, for example, detecting the power available to the individual electrolyzer of each core. In cases where the power supply unit of each core within the plurality of cores is redundant with respect to the power supply unit of at least one other core of the plurality of cores, the step of detecting the power available to the individual electrolyzer of each core may be based on a first available power output of the power supply unit corresponding to a given core and a second available power output of one or more power supply units that are redundant with respect to the power supply unit of the given core. As described in more detail below, in cases where the total available power for a given core corresponds to a hydrogen production capacity that is less than the rated hydrogen output for the core, the total available power for the core may limit the amount of hydrogen that can be produced from the core.

[0045] The hydrogen production capacity of a given core can be based on the conditions of the power supply unit and any associated redundant power supply units, but it should be understood that the hydrogen production capacity of the core can also, additionally or alternatively, be based on the conditions of the electrolyzer. For example, in the case where the electrolyzer includes an electrochemical stack, the step of monitoring the hydrogen production capacity of the core, including such an electrolyzer, may include sending a signal to the power supply unit of an individual core, sending a current interruption or ripple function to the electrochemical stack, and receiving a current interruption impedance measurement of the electrochemical stack in response to the current interruption or ripple function. The current impedance measurement may be an electrochemical impedance spectroscopy (EIS) measurement. Consequently, the current interruption impedance measurement may provide an indication of the amount of input power lost within the electrochemical stack. As the electrochemical stack ages, this loss may increase over time. Therefore, by monitoring this degradation, adjustments to the operating set points of one or more other cores within a plurality of cores may be made to compensate for such degradation. Thus, the EIS measurement may be performed during steady state operation, shutdown procedures, or startup or recovery procedures.

[0046] As shown in step 204, the exemplary method 200 may include the step of assessing the power available to a plurality of cores from one or more power sources. For example, in cases where a plurality of cores receive power from one or more local power sources, it should be understood that the power available from such one or more local power sources may vary significantly over time. This may particularly apply to intermittent power sources. Thus, in some cases, the step of assessing the power available to a plurality of cores may include the step of determining the amount of available power from one or more intermittent power sources, since it may be advantageous to use such intermittent power before other sources of nominally constant power (e.g., to reduce the need to store such intermittent power). Additionally, or alternatively, the step of assessing the power available to a plurality of cores from one or more power sources may include the step of determining the amount stored in one or more batteries that are in electrical communication with the individual power supplies of each core, and thus the stored power can advantageously be used for the smooth intermittency of power from the intermittent power source.

[0047] As shown in step 206, the exemplary method 200 may include the step of setting the individual operating set points of each core within the plurality of cores such that the plurality of cores collectively meet a predetermined performance goal. As used in this context, the predetermined performance goal may be any one or more of a variety of different goals that may be associated with the operation of a modular system for hydrogen generation, particularly the operation of such a system to reduce the likelihood of an unscheduled interruption in hydrogen production. For example, the predetermined performance goal may include an equilibrium between the total power collectively required for the operating set points of the plurality of cores and the amount of power available from the intermittent power source. Additionally, or alternatively, the predetermined performance goal may include maximum power point tracking of the intermittent power source such that the total power collectively required for the operating set points of the plurality of cores corresponds to the maximum available power from the intermittent power source without requiring excess power from other sources.

[0048] In one embodiment, power source 120 includes a photovoltaic array, which is directly coupled to core 102, and which tracks the photovoltaic array output power. In another embodiment, power source 120 includes a wind power source (e.g., a wind turbine), which is directly coupled to core 102, and which tracks the wind power generation output power. In another embodiment, the power grid power source 120 provides more power to core 102 during off-peak hours and less power to core 102 during peak hours, enabling load leveling of the power grid.

[0049] As another example, a given performance goal may include the overall efficiency of the target of multiple cores. Such efficiency may be measured against any one or more of various different parameters of the system. For example, the overall efficiency of the target may correspond to maximizing the production value / cost ratio. In this context, the production value may be based on production requirement projections for hydrogen, oxygen, and heat, and the cost may be based on current electricity prices.

[0050] Generally, in order to achieve a performance goal through the collective operation of a plurality of cores, the step of setting the operating set point for an individual core may be based on the hydrogen production capacity for a given core and / or the power available to the core from one or more power supplies. For example, if the first available power output to the core (from the primary power supply) and the second available power output to the core (from one or more power supplies providing redundant power) each correspond to a hydrogen production capacity less than the rated hydrogen output of a given core, the operating set point for the given core may be set according to the greater of the first available power output or the second available power output. In some cases, the operating set points of one or more other cores may be adjusted to compensate for a lower hydrogen output. That is, if the individual hydrogen production capacity of one of the cores within the plurality of cores is less than the rated hydrogen output for the individual core, the step of setting the individual operating set point for each core within the plurality of cores includes the step of setting the operating set point of at least one other core within the plurality of cores above the rated hydrogen output for at least one other core. In other words, in some cases, the total hydrogen output from the plurality of cores may be maintained substantially constant (e.g., varying by less than about ±10 percent). In one implementation, the step of setting the individual operating set point for each core within the plurality of cores may additionally or alternatively include the step of adding additional cores to the plurality of cores so as to be useful for achieving a predetermined performance goal, including maintaining a substantially constant voltage (e.g., varying by less than about ±10 percent) across the plurality of cores during full power operation.

[0051] As shown in step 208, the exemplary method 200 may include directing power available from one or more power supplies to a plurality of cores according to individual operating set points of each core. In one case, this may include checking the impedance of the wiring for each core and, if the impedance of the wiring exceeds a predetermined threshold, interrupting at least the available power directed to the individual core. That is, if the impedance of the wiring associated with a given core appears to indicate a short circuit condition, the power to the given core may be interrupted and / or redirected to one or more other cores.

[0052] Referring now to FIGS. 2A - 2C, the exemplary method 200 may further include performing one or more additional protocols associated with the safety and productivity of the system.

[0053] As shown in FIG. 2B, the exemplary method 200 may include executing a startup protocol 210 for a plurality of cores.

[0054] As shown in step 212, the startup protocol 210 may include, for example, a leak test step. Components are tested for leaks by pressurizing the components of each core and interrupting the startup protocol if a pressure decay exceeding a predetermined threshold is detected within one or more of the pressurized components of an individual core. Specifically, the leak test may be performed by pressurizing the hydrogen and water as well as the coolant lines and then checking for pressure decay and continuing operation only if the pressure is maintained high, indicating non - leak conditions. The startup protocol 210 may also include a de - electrical connection test. Electrical wiring and connections are accompanied by an electrical impedance check, and the system is enabled to continue operating only if the impedance of the wiring and connections is below a threshold and / or does not exhibit signs of a short - circuit or open - circuit fault.

[0055] As shown in step 214, the startup protocol 210 may include the step of purging at least a portion of the core (e.g., electrolytic cell) with an inert gas or oxygen-depleted air. Such oxygen-depleted air may have, for example, about 16 percent oxygen or less and may be formed according to any one or more of a variety of different techniques for removing oxygen from air, such as oxygen pumping, temperature swing adsorption, pressure swing adsorption, hybrid generators, or cascade oxygen removal processes used to produce nitrogen in ammonia formation. As used herein, such oxygen-depleted air may be delivered to the plurality of cores via the nitrogen module 240 of the hub. Further, or alternatively, in cases where each core includes a fuel cell as an auxiliary power source, the startup protocol may include the step of directing hydrogen to the fuel cell to provide power for the startup and warm-up of the individual cores.

[0056] As shown in step 216, the startup protocol of step 210 may include the step of incrementing each core to an individual operating set point for a given core. The incrementing protocol may be a predetermined protocol based on one or more considerations related to safety and / or component integrity.

[0057] As shown in FIG. 2C, the exemplary method 200 may include the step of executing a shutdown protocol 218 for the plurality of cores. The shutdown protocol of the exemplary method 200 may include the step of executing a shutdown protocol for the plurality of cores.

[0058] As shown in step 220, the shutdown protocol 218 may include the step of de-energizing the power supply of each core.

[0059] As shown in step 222, the shutdown protocol 218 may include the step of purging at least a portion of the core (e.g., electrolytic cell) with an inert gas (e.g., nitrogen) or oxygen-depleted air, as described above.

[0060] As shown in step 224, the shutdown protocol 218 may include maintaining a voltage bias across the electrolyzer. The step of holding the bias across the electrolyzer may be performed, for example, by a battery and / or auxiliary power supply in electrical communication with the electrolyzer. For example, the electrolyzer may operate in a night mode that produces a small amount of hydrogen using a small amount of water volume. This may advantageously reduce the number of start-stop cycles for the electrolyzer that could otherwise degrade the performance of the electrolyzer. In cases where the electrolyzer includes an electrochemical stack, the step of maintaining a voltage bias across the electrolyzer may include maintaining the bias across the anode and maintaining hydrogen on the cathode side, or maintaining the voltage bias across the cathode and pumping oxygen back into the water. More generally, the step of maintaining a bias across the electrochemical stack may be useful for assessing the health conditions (e.g., current or hydrogen pumped from the anode to the cathode at low pressure) within the electrolyzer stack during a healthy shutdown.

[0061] As shown in step 226, the shutdown protocol of step 218 may include reversing the polarity of the DC power supply associated with a given core electrolyzer. Such a reversal of polarity may be useful, for example, in cases where the electrolyzer includes such an electrochemical cell, for removing materials accumulated on the electrochemical cell.

[0062] The above-described systems, devices, methods, processes, and equivalents may be implemented in hardware, software, or any combination thereof suitable for control, data access, and data processing as described herein. The hardware may include general-purpose computers and / or dedicated computing devices. This may include implementation within one or more microprocessors, microcontrollers, embedded microcontrollers, programmable digital signal processors, or other programmable devices or processing circuits, along with internal and / or external memory. This may also include, or alternatively, one or more application-specific integrated circuits, programmable gate arrays, programmable array logic components, or any other device or devices that may be configured to process electronic signals. Further, the realization of the processes or devices described above may include computer-executable code generated using a structured programming language such as C, an object-oriented programming language such as C++, or any other high-level or low-level programming language (including assembly language, hardware description language, and database programming languages and techniques) that is stored, compiled, or interpreted and executed on one of the aforementioned devices, as well as on heterogeneous combinations of processors, processor architectures, or different combinations of hardware and software. At the same time, the processing may be distributed across the various systems and other devices described above, or all functionality may be integrated within a dedicated stand-alone device. All such permutations and combinations are intended to be within the scope of this disclosure.

[0063] Embodiments disclosed herein may include a computer program product comprising computer-executable code or computer-usable code that, when executed on one or more computing devices, performs any and / or all of the steps of the control systems described above. The code may be stored in a computer memory in a non-transitory manner, which may be the memory in which the program executes (such as random access memory associated with a processor), or a storage device such as a disk drive, flash memory, or any other optical, electromagnetic, magnetic, infrared, or other device or combination of devices. In another aspect, any of the control systems described above may be embodied in any suitable transmission or propagation medium that carries computer-executable code and / or any input thereto or output therefrom.

[0064] The method steps of the implementations described herein are intended to include any suitable method of carrying out such method steps in a manner consistent with the patentability of the following claims, unless a different meaning is explicitly provided or otherwise apparent from the context. Thus, for example, performing step X may include any suitable method of causing another party, such as a remote user, remote processing resource (such as a server or cloud computer), or machine, to perform step X. Similarly, performing steps X, Y, and Z may include any method of instructing or controlling any combination of such other individuals or resources to perform steps X, Y, and Z and obtain the benefits of such steps. Accordingly, the method steps of the implementations described herein are intended to include any suitable method of causing one or more other parties or entities to perform steps in a manner consistent with the patentability of the following claims, unless a different meaning is explicitly provided or otherwise apparent from the context. Such parties or entities need not be under the instruction or control of any other party or entity and need not be located within a particular jurisdiction.

[0065] It should be understood that the devices, systems, and methods described above are presented by way of example and not limitation. Numerous variations, additions, omissions, and other modifications will be apparent to those skilled in the art. Additionally, the order or presentation of method steps in the above description and drawings is not intended to require the recited order of performing the steps, unless a particular order is explicitly required or otherwise apparent from the context. Thus, while particular embodiments have been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications in form and detail may be made therein without departing from the scope of the present disclosure.

Claims

1. A modular system for hydrogen generation, comprising a plurality of cores, each core including an electrolytic cell and a power supply unit, the power supply unit of each core being operable to manage the power to the electrolytic cell of the core, the power supply unit of each core being redundant with respect to the power supply unit of at least one other core, and the power supply unit of each core being hot-swappable while the individual electrolytic cell of the core is in operation, a plurality of cores; a hub, the hub including a water module, a heat exchange module, and a switchgear module, the water module having a water source in fluid communication with the electrolytic cell of each of the plurality of cores, the heat exchange module having a heat exchanger in thermal communication with the electrolytic cell of each of the plurality of cores, the switchgear module having a switch activatable to electrically isolate the power supply unit of each of the plurality of cores, a hub A modular system comprising.

2. The modular system according to claim 1, wherein each power supply unit is in thermal communication with the heat exchanger.

3. The modular system according to claim 1, wherein each power supply unit is connected to both a DC power supply and an AC power supply.

4. The modular system according to claim 1, wherein each power supply unit is configured to provide a first DC voltage to the electrolytic cell of the core and a second DC voltage lower than the first DC voltage to an auxiliary device of the core.

5. The modular system according to claim 1, wherein each core further includes an auxiliary power supply in electrical communication with the individual electrolytic cell of a given core.

6. The electrolytic cell includes an electrochemical stack, water from the water module is receivable into the electrochemical stack, The modular system according to claim 1, wherein the electrochemical stack is configured to receive power from the power supply unit and generate hydrogen and oxygen from the water.

7. The modular system according to claim 6, wherein the electrochemical stack comprises a proton exchange membrane stack, a solid oxide electrolysis stack, an alkaline cell stack, or a combination thereof.

8. The hub a compression module including a compressor in fluid communication with the electrolytic cell of each core, a storage module in fluid communication with the compression module The modular system according to claim 1, further comprising.

9. The modular system according to claim 1, wherein the heat exchange module comprises a heat loop, and the heat exchanger is in thermal communication with each of the plurality of cores via the heat loop.

10. The modular system according to claim 9, wherein the heat exchanger and the heat loop form at least a part of a heat pump operable to convert waste heat from the plurality of cores into heat deliverable to one or more other parts of the hub.

11. The modular system according to claim 1, wherein each of the water module, the heat exchange module, and the switch module is replaceable through at least one of disconnection of only one electrical connection, only one fluid connection, or only one thermal connection.

12. The modular system according to claim 3, wherein each power supply unit is configured to provide DC power to the electrolytic cell of each core.

13. The modular system according to claim 1, wherein the power supply unit comprises one or more of an inverter, a rectifier, and a transformer.

14. The modular system according to claim 3, wherein the DC power supply and the AC power supply each comprise a photovoltaic array.

15. The modular system according to claim 3, wherein the DC power supply and the AC power supply each comprise a power transmission network.

16. The modular system according to claim 1, wherein the water module further comprises a pump in fluid communication with the water source and a filter in fluid communication with the water source.

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