Control of solid oxide electrolyzer

Abstract

To provide a solid oxide electrolyzer cell (SOEC) system that provides flexible system installation and operation.SOLUTION: A modular SOEC system includes: a stack of electrolyzer cells configured to receive steam in combination with hydrogen; and a steam recycle outlet configured to recycle a portion of the steam.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] SUMMARY OF THE INVENTION Embodiments of the present invention generally relate to electrolyzer systems including solid oxide electrolysis cells (SOECs) and methods of operation thereof. [Background technology]

[0002] A solid oxide fuel cell (SOFC) can operate as an electrolyzer to produce hydrogen and oxygen, which is called a solid oxide electrolysis cell (SOEC). In SOFC mode, oxygen ions are transported from the cathode side (air) to the anode side (fuel), driven by a chemical gradient of oxygen partial pressure across the electrolyte. In SOEC mode, oxygen ions are transported from the fuel side to the air side when a positive potential is applied to the air side of the cell. Because the cathode and anode are reversed between SOFCs and SOECs (i.e., the SOFC cathode becomes the SOEC anode and the SOFC anode becomes the SOEC cathode), the SOFC cathode (SOEC anode) can be referred to as the air electrode, and the SOFC anode (SOEC cathode) can be referred to as the fuel electrode. During SOEC mode, water in the fuel stream is reduced (HO + 2e → O 2- +H2), H2 gas and O 2- ions, forming O 2- After transporting through the solid electrolyte, the ions are oxidized (O 2- The open circuit voltage of an SOFC operating with air and a moist fuel (hydrogen, reformed natural gas) is approximately 0.9V to 1V (depending on the water content), so a positive voltage applied to the air electrode in the SOEC mode raises the cell voltage to a typical operating voltage of 1.1V to 1.3V. Summary of the Invention

[0003] Accordingly, the present invention is directed to a modular electrolyzer system that substantially obviates one or more of the problems resulting from limitations and disadvantages of the related art.

[0004] Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and appended claims when taken in conjunction with the appended drawings.

[0005] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

[0006] The accompanying drawings, which are included to provide a further understanding of the invention, and which are incorporated into and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating a SOFC / SOEC modular system according to one exemplary embodiment of the present invention. [Figure 2] FIG. 2 is a diagram illustrating a large scale electrolyzer system according to an exemplary embodiment of the present invention. [Figure 3] FIG. 3 is a diagram illustrating a large scale electrolyzer system according to another exemplary embodiment of the present invention. [Figure 4] FIG. 4 is a diagram illustrating a large scale electrolyzer system according to an exemplary embodiment of the present invention. [Figure 5] FIG. 5 is a diagram of an SOEC system according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0008] Reference will now be made in detail to embodiments of the invention, examples of which are illustrated in the accompanying drawings. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed.

[0009] FIG. 1 illustrates a SOFC / SOEC modular system 10 according to one exemplary embodiment of the present invention.

[0010] The modular design of the SOFC / SOEC system 10 provides flexible system installation and operation. In contrast to previous modular systems, embodiments use above-ground routing of piping and electrical wiring to increase the speed and reduce costs of installation and maintenance. Additionally, the need for specialized installation contractors is reduced. The modules allow for scaling of installed power generation capacity, reliable power generation, fuel processing flexibility, and power output voltage and frequency flexibility using a single set of designs. The modular design results in an "always-on" unit with very high availability and reliability, and also improves the means for maintenance and scale-up. The modular design also allows for the use of available fuels and required voltages and frequencies, which may vary depending on the customer and / or geographic region.

[0011] The SOFC / SOEC modular system 10 includes a housing 14 within which are disposed at least one of a generator module 12 (preferably multiple generator modules 12, also referred to as an "SGM"), one or more fuel processing modules 16 (within the SOFC system), and one or more power conditioning modules 18 (i.e., also referred to as electrical outputs, generator modules, or "SPMs"). In these exemplary embodiments, the power conditioning modules 18 may include mechanisms for converting DC to AC or AC to DC, such as inverters. For example, the system 10 may include any desired number of modules, such as 2 to 30 generator modules, 3 to 12 generator modules, 6 to 12 modules, or other large-scale configurations of generator modules.

[0012] The example system 10 of FIG. 1 includes a number of generator modules 12 (a row of six modules arranged side-by-side), a fuel processing module 16 (in an SOFC system), and a power conditioning module 18 on a pad 20. The housing 14 may include a cabinet that houses each of the modules 12, 16, and 18. Alternatively, the modules 16 and 18 may be disposed within a single cabinet. While a single row of generator modules 12 is shown, the system may include two or more rows of modules 12. For example, the SOFC / SOEC system 10 may include two rows of generator modules 12 arranged back-to-back / end-to-end.

[0013] Each generator module 12 is configured to house one or more hot boxes 13. Each hot box houses one or more stacks or columns of fuel cell / electrolyzer cells (not shown for clarity), such as one or more stacks or columns of solid oxide fuel cells having a ceramic oxide electrolyte separated by conductive interconnect plates. Other types of fuel cells, such as PEM, molten carbonate, phosphoric acid, etc., can also be used.

[0014] Fuel cell stacks can include externally and / or internally manifolded stacks. For example, the stacks can be internally manifolded for fuel and air with fuel and air risers extending through openings in the fuel cell layers and / or interconnect plates between the fuel cells.

[0015] Alternatively, the fuel cell stack may be internally manifolded for fuel and externally manifolded for air, in which case only the fuel inlets and exhaust risers pass through openings in the fuel cell layers and / or interconnect plates between the fuel cells. This is described in U.S. Pat. No. 7,713,649, which is incorporated herein by reference in its entirety. The fuel cells can have a cross-flow configuration (air and fuel flow generally perpendicular to each other on opposite sides of the electrolyte in each fuel cell), a counter-current parallel configuration (air and fuel flow generally parallel to each other but in opposite directions on opposite sides of the electrolyte in each fuel cell), or a parallel-current parallel configuration (air and fuel flow generally parallel to each other in the same direction on opposite sides of the electrolyte in each fuel cell).

[0016] The fuel processing module 16 and the power conditioning module 18 may be housed within a single cabinet in the housing 14. As shown in the exemplary embodiment of Figure 1, one cabinet 14 is provided for a row of six (or any number) generator modules 12, with the six generator modules 12 arranged linearly side-by-side on one side of the input / output module 14. The row of modules may be positioned, for example, adjacent to the building to which the system provides power (e.g., with the backs of the module cabinets facing the wall of the building).

[0017] The linear array of generator modules 12 is easily scalable. For example, more or fewer generator modules 12 may be provided depending on the power needs of the building or other facility served by the fuel cell / electrolyzer system 10. Other ratios of generator modules 12 and input / output modules 14 may also be provided. For example, in other exemplary embodiments, more or fewer generator modules 12 may be provided adjacent to input / output modules 14. Furthermore, support functions may be served by more than one input / output module 14 (e.g., using separate fuel processing module 16 and power conditioning module 18 cabinets). Furthermore, although the input / output modules 14 are at the ends of the rows of generator modules 12, they may also be located in the middle of the rows of generator modules 12 or elsewhere.

[0018] The SOFC / SOEC modular system 10 can be configured to facilitate maintenance of system 10 components. For example, components that are routinely or frequently maintained (such as consumable parts) may be located in a single module, reducing the time required by maintenance personnel. For example, the purge gas (optional) can be located in a single module (e.g., the fuel processing module 16 or the combined input / output module 14 cabinet). This can be the only module cabinet accessed during routine maintenance. Thus, each module 12, 14, 16, and 18 can be maintained, repaired, or removed from the system without opening the other module cabinets and without servicing, repairing, or removing the other modules. Additionally, piping and electrical components can be located on a steel overlay that is located between the concrete pad and the generator module 12.

[0019] For example, as described above, the system 10 can include multiple generator modules 12. When at least one generator module 12 goes offline (i.e., no power is produced by the stack in the hot box 13 in the offline module 12), the remaining generator modules 12, fuel processing modules 16, and power conditioning modules 18 (or combined input / output modules 14) will not go offline. Furthermore, the fuel cell / electrolyzer system 10 can include more than one of each type of module 12, 14, 16, or 18. When at least one module of a particular type goes offline, the remaining modules of that same type will not go offline.

[0020] Thus, in a system with multiple modules, each of modules 12, 14, 16, or 18 can be electrically disconnected, removed from fuel cell / electrolyzer modular system 10, and / or serviced or repaired without shutting down the operation of the other modules in the system, allowing the fuel cell system to continue generating electricity. If one stack of fuel cells / electrolyzers in one hot box 13 fails or is taken offline for maintenance, the entire SOFC / SOEC modular system 10 does not need to be shut down.

[0021] FIG. 2 shows a large scale electrolyzer system 200 according to one exemplary embodiment of the present invention.

[0022] The large-scale electrolyzer system 200 comprises a gas distribution module ("GDM") 250 configured to supply start-up hydrogen to multiple modular blocks 210, 220, 230, 240. SOEC and SOFC systems typically require fresh hydrogen gas for start-up and shutdown. The gas distribution module 250 may further comprise a pressure detector, a heat detector, a gas safety shutoff, and a purge gas distributor.

[0023] As mentioned above, each modular block includes, for example, one power module ("SPM") and one or more generator modules ("SGMs"). A grouping of modular blocks into a system collection is referred to as a stamp. Thus, the large-scale electrolyzer system 200 is a stamp. Because hydrogen is a flammable gas that is supplied under pressure to each SGM, a safe method of shutting off gas to the group of generator modules SGMs is required when a safety event is detected. Therefore, the GDM 250 is configured to shut off the hydrogen supplied to the SGMs when a safety event is detected. Safety designs such as pressure detection, overpressure protection, and gas safety shutoff are easily applied within the electrolyzer system 200 by the GDM 250 and / or the fuel processing module (e.g., 16). Additionally, a stamp-level controller can be provided in the GDM 250.

[0024] The grouping of four modular blocks 210, 220, 230, and 240 is an exemplary configuration, and is an efficient grouping for gas safety. Additionally, the grouping of four modular blocks 210, 220, 230, and 240 is efficient for collecting hydrogen product in service aisle 260. Pipe 261 in service aisle 260 is configured to collect hydrogen product for integration with the downstream compression system. Pipe 261 is configured to prevent backflow of condensate into generator module SGM. Condensate management also allows for return to the water outlet (or BOP1) using various monitoring and control devices and pipes.

[0025] Figure 3 shows a large-scale (e.g., 10 megawatt system) electrolyzer system 300 according to one exemplary embodiment of the present invention. As shown in Figure 3, the electrolyzer system 300 comprises multiple stamps 310, 320, 330, 340, 350, 360, and 370. In addition, the electrolyzer system 300 further comprises additional balance of plant components, such as a water source BOP1, a hydrogen product collection section BOP2 (e.g., including line 261), and a hydrogen compression and processing section BOP3. The hydrogen compression and processing section BOP3 is functionally configured to supply hydrogen under pressure to the gas distribution modules (e.g., GDMs 250) for each stamp 310, 320, 330, 340, 350, 360, and 370. Thus, the stamp architecture can be repeated in large-scale designs by assembling repeating elements for large-scale installations.

[0026] Figure 4 shows a large-scale electrolyzer system 400 according to one exemplary embodiment of the present invention. The components of electrolyzer system 400 are similar to electrolyzer systems 200 and 300, with differences and / or additional features described below. In particular, Figure 4 shows various communicatively coupled (e.g., Ethernet, internet, hardwired, etc.) controllers in electrolyzer system 400.

[0027] In various embodiments of the present invention, various systems, apparatus, methods, and non-transitory computer-readable instructions are provided for a customer to operate the SOEC site and system. For example, a centralized controller (e.g., an embedded controller) is provided to receive commands from the customer at different system levels (e.g., a site-level safety controller, a site-level controller, a stamp-level controller, a modular block controller, a power module controller, a generator module controller). Various decisions are made at each level to reduce data traffic on the communication bus between components of the electrolyzer system 400.

[0028] For example, take a field-level controller. If there are multiple telemetry cabinets (TCs) at each field, the field-level controller can be configured to communicate with a controller in each telemetry cabinet. In another configuration, if there is a single telemetry cabinet at a field, the controller in the telemetry cabinet can be configured as the field-level controller.

[0029] The field level controller can be configured as a controller that receives customer commands and communicates with an IO board that monitors safety signals. The field level controller can be connected to a field level safety controller. The field level controller can also be connected to a utility (e.g., a power supplier) to receive commands regarding available power and interlocks.

[0030] In various configurations, the site level controller can be configured to perform a variety of functions, including determining available power at the site level, hydrogen generation demand at the site level, calculated available power per stamp, calculated hydrogen generation demand per stamp, site level safety signal, deionized ("DI") skid water quality signal, energy meter power readback at the site level, total energy meter power readback at the site level, power readback at each and / or all stamps, calculated power readback at the site level, water / steam temperature and pressure readback at the site level, hydrogen temperature and pressure readback at the site level, hydrogen production rate readback at all stamps, calculated hydrogen production rate readback at the site level, calculated hydrogen generation efficiency (kWhr / kg) at the site level, collected alarm summary for each and / or all stamps, action required for each and / or all stamps, etc.

[0031] For example, take a stamp-level controller. Each of the controllers in a modular block (e.g., modular blocks 210, 220, 230, 240) is communicatively and functionally coupled to report to one controller at the stamp level. The stamp-level controller can be configured to collect various data (e.g., those listed above) from each modular controller and further configured to report back to a field-level controller or telemetry controller.

[0032] Here, the stamp level controller is configured to link communications between the stamp level compression system and each modular block, in other words, the stamp level controller acts as a gateway to pass alarms and / or other data from the field level and compression skid to each modular block controller and from the modular block controller back to the field level controller and compression skid.

[0033] If the stamp level controller is disconnected from the network or is removed by design, a controller in the telemetry cabinet can be configured to implement the functionality of the stamp level controller.

[0034] In various configurations, the stamp level controller can be configured to perform a variety of functions, including determining calculated available power for each and / or all modular blocks, calculated hydrogen generation demand for each and / or all modular blocks, power readback for each and / or all modular blocks, calculated power readback at the stamp level, water / steam temperature and pressure readback at the stamp level, hydrogen temperature and pressure readback at the stamp level, hydrogen production rate readback for each and / or all modular blocks, calculated hydrogen production rate readback at the stamp level, calculated hydrogen generation efficiency (kWhr / kg) at the stamp level, a summary of collected alarms for each and / or all modular blocks, required action for each and / or all modular blocks, etc.

[0035] In various configurations, the modular block controller (and power module controller) can be configured to monitor the generator modules in a module. Additionally, the modular block controller (and power module controller) can be configured as a gateway for all safety alarms to / from the generator modules. The modular block controller (and power module controller) can be configured to perform a variety of functions, including determining the calculated available power for each and / or all generator modules, the calculated hydrogen generation demand for each and / or all generator modules, the power readback for each and / or all generator modules, the calculated power readback at the modular block level, the water / steam temperature and pressure readback at the modular block level, the hydrogen temperature and pressure readback at the modular block level, the hydrogen production rate readback for each and / or all generator modules, the calculated hydrogen production rate readback at the modular block level, the calculated hydrogen generation efficiency (kWhr / kg) at the modular block level, a summary of collected alarms for each and / or all generator modules, the required action for each and / or all generator modules, etc.

[0036] For example, consider a generator module controller. The generator module controller is configured to monitor sensors in each generator module and perform functions based on commands received from an operator and / or a higher-level controller. The generator module controller is communicatively and functionally coupled to the modular block controller. For example, the generator module is configured to return necessary critical data to the modular block controller.

[0037] In various configurations, the generator module controller can be configured to perform a variety of functions, including determining power readback, hydrogen production rate readback, water / steam temperature and pressure readback, hydrogen temperature and pressure readback, hydrogen production rate readback, calculated hydrogen generation efficiency (kWhr / kg), alarm summaries, etc.

[0038] FIG. 5 is an SOEC system 500 according to one exemplary embodiment of the present invention.

[0039] As shown in FIG. 5, the SOEC system 500 includes an air conduit 105, an air blower 106, an air inlet 107, a steam conduit 110, a recirculated steam inlet 111, a hot box 150, an optional hydrogen conduit 130, an enriched air outlet 123, an enriched air conduit 125, an enriched air blower 126, a steam and hydrogen product outlet 120, a splitter 160, a venturi flow meter 165, a steam recirculation blower 170, a heat sensor 175, and a customer 190 (e.g., a user, operator, or their computer).

[0040] According to one exemplary configuration and operation, steam supplied in steam conduit 110 (e.g., supplying on-site or facility steam at various pressures) can have a temperature of approximately 100°C to 110°C (e.g., 105°C) and a pressure of approximately 1 psig. In various embodiments, steam can be supplied to SOEC system 500 from an external source or can be generated locally. In some embodiments, multiple steam inlets can be configured to receive external steam and local steam, respectively. Alternatively or additionally, water can be supplied to SOEC system 500 and vaporized.

[0041] The air supply (e.g., ambient air) in air conduit 105 may be at ambient temperature at local atmospheric pressure, which may be approximately −20° C. to +45° C. The air from air conduit 105 is received at air blower 106, and the air discharged by air blower 106 is at a slightly higher temperature than ambient due to the heat of compression. For example, the temperature of the air discharged by air blower 106 may be approximately 30° C. at 1.0 psig, compared to an ambient air temperature of 20° C. The air supply in air conduit 105 is then received at air inlet 107 of hot box 150.

[0042] Hydrogen from optional hydrogen conduit 130 may be needed only for startup and transients when hydrogen is not otherwise being produced by SOEC system 500. For example, a separate hydrogen feed stream or hydrogen recycle steam may not be needed at steady state. The pressure of this hydrogen stream is a design option determined at the time of on-site construction and may be between about 5 psig and 3000 psig. The temperature may be near ambient, as it may come from a reservoir.

[0043] The air supply in air conduit 105, the steam supply in steam conduit 110, and the optional hydrogen supply in hydrogen conduit 130 are fed to hot box 150. Hot box 150 also outputs steam and hydrogen product H-H0-G at steam and hydrogen product outlet 120 of hot box 150, where G represents gross. Hot box output H-H0-G can have a temperature of about 100°C to 180°C (e.g., 130°C) and a pressure of about 0.1 psig to 0.5 psig.

[0044] Additionally, the hot box effluent H-H0-G is fed to splitter 160 and split into a vapor recycle stream RECH2OLP (where LP stands for low pressure) and a pure product H-H0-N (where N stands for net) (e.g., effluent for commercial use or storage). Here, the pure product H-H0-N can have a temperature of about 100°C to 180°C (e.g., 130°C) and a pressure of about 0.1 psig to 0.5 psig. The vapor recycle stream RECH2OLP can have a temperature of about 100°C to 180°C (e.g., 130°C) and a pressure of about 0.1 psig to 0.5 psig. The hot box 150 may further discharge enriched air at enriched air outlet 123 via enriched air conduit 125, which may have a temperature of approximately 120°C to 300°C at essentially local atmospheric pressure (e.g., less than 0.5 psig or less than 0.05 psig).

[0045] The steam recycle stream RECH2OLP is supplied to steam recycle blower 170. The resulting recycle steam REC-STM can have a temperature of about 100°C to 180°C (e.g., 140°C, 154°C) and a pressure of about 0.5 psig to 1.5 psig (e.g., about 1 psig) and is supplied to hot box 150 at recycle steam inlet 111. In some embodiments, a recycle hydrogen feed may not be included with the recycle steam.

[0046] As can be seen from FIG. 5 , the inlet steam temperature (e.g., 105° C.) in steam conduit 110 is lower compared to SOEC configurations with internal steam generation. In various configurations, multiple recirculation loops can be configured for SOEC systems using both internal and external steam generation. As shown, recirculation steam inlet 111 is configured to receive steam from steam conduit 110. Here, embodiments optionally direct the steam supplied to the facility from steam conduit 110, which is typically saturated and at a temperature of about 105° C., through internal steam generation coils, one or more vaporizers, and / or other heating elements, and use the air exhaust heat (e.g., about 280° C.) to further heat (i.e., superheat) the steam supply before the heat is released in enriched air conduit 125 through optional fan or enriched air blower 126.

[0047] In some embodiments, a customer 190 is enabled to control a solid oxide electrolysis cell (SOEC) system. One or more interfaces provide a custom communication protocol (e.g., via Ethernet, internet, hardwired, etc.) that receives and executes customer commands to operate the SOEC in different states. Thus, embodiments provide support for meeting customer needs to utilize renewable hydrogen while ensuring safe operation of the SOEC.

[0048] For example, embodiments allow a customer or other third party to control the SOEC system using parameters such as hydrogen generation, power limits, and available steam. In some embodiments, a system is provided that can transition to a safe standby state if communication is lost. Furthermore, the safe standby state can be defined based on conditions agreed to by the customer.

[0049] Additionally or alternatively, embodiments may provide one or more mechanisms for customers to operate the SOEC system, provide safety logic to stay within safe limits of operation, and enable ramping of hydrogen production to ensure hydrogen generation meets customer needs. In some examples, customers may receive advance notice of upcoming on-site limitations (e.g., external hydrogen unavailability, available power schedules, communication limitations to power storage, water and supply hydrogen storage limitations, etc.). Thus, customers may adjust for such limitations (e.g., adjust hydrogen generation based on on-site hydrogen usage or hydrogen storage limitations).

[0050] The amount of hydrogen produced by the SOEC system 500 depends on the power drawn from the grid or external power supply, the available water and / or steam sources, and the number of cells in the system.

[0051] Once the SOEC system 500 is powered, the embedded controller can be configured to indicate that the system is ready to start. In this state, the customer 190 can send a start command and begin the heating process. From this point on, the SOEC system 500 manages the subsystems internally.

[0052] Once the heating process is complete, it will automatically transition to the H2 generation enabled state. In this state, the customer 190 can send a command to allow H2 generation if their internal safety needs are met. The SOEC controller will also check for any safety issues that may prevent the transition to the H2 generation state.

[0053] In the H2 generation state, the H2 generation rate can be commanded. Internally, the SOEC performs a calculation of Target H2 Generation = min (Allowable H2 Generation Rate, Customer H2 Generation Rate) to ensure that the target H2 generation rate meets the requirements based on the available power and water / steam supply. The Allowable H2 generation rate is calculated as follows:

[0054] Allowable H2 production rate = function(available power, available steam flow, available fresh H2)

[0055] If a safety alarm detects that the required water / steam source is not available, the SOEC system 500 transitions to a hot standby state. This state allows for temperature maintenance but does not allow customers to generate hydrogen. However, once the issue is resolved, the SOEC system 500 can return to its previous state (e.g., H2 generation, heating state).

[0056] Regarding alarms, the SOEC system integrates a wide set of safety and operational alarms that, when triggered, can bring the system to a safe shutdown, and customers can clear alarms and restart the SOEC system 500 through an alarm clear command.

[0057] Finally, if the customer 190 deems it desirable to cool down the system, this can be accomplished through a controlled shutdown command that puts the SOEC system 500 into a controlled shutdown state.

[0058] If communication between the customer and the SOEC system 500 is lost, internal logic retains the most recent commands available, ensuring that the system can continue safe operation based on the most recent commands sent by the customer 190. Once communication loss is detected, the system can also revert to master mode, allowing the SOEC operator to return the system to a desired state.

[0059] Allowing customers to operate the system based on their production needs reduces concerns about hydrogen supply availability. Embodiments of the present invention provide a communication interface to send commands to the SOEC and a closed-loop system to transition the system into different operating modes while ensuring safety.

[0060] The primary function of SOECs is to use electricity to split water molecules into hydrogen and oxygen through an electrolysis process, after which the hydrogen gas can be captured and used for multiple applications, such as injection into natural gas pipelines, hydrogen-powered vehicles, and long-term storage, among others.

[0061] In each of the various embodiments described herein, one or more sensors or detectors can be used to detect safety events. For example, one or more pressure detectors and one or more heat detectors can be used. One or more pressure detectors can be placed along the supply hydrogen conduit to detect underpressure (e.g., less than 5 PSI) and overpressure. If a pressure detector trips, the system (i.e., hot box 150) shuts down. Additionally, one or more heat detectors can be placed within the hot box cabinet to detect excessive heat (e.g., greater than 230°C). Cabinet ventilation is provided and maintained, for example, by enriched air blower 126. If a heat detector trips, the system (i.e., hot box 150) shuts down.

[0062] The SOEC system (e.g., 100) stops receiving hydrogen when the SOEC system is operating at steady state or upon detection of a safety event. Additionally, the stack of electrolytic cells in the hot box 150 can be configured to receive hydrogen during startup, shutdown, or when the SOEC system is not producing hydrogen.

[0063] It will be apparent to those skilled in the art that various modifications and variations can be made in the control of the electrolytic cell system of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Claims

1. A stamp comprising: a plurality of stamps each including a grouping of modular blocks; Stamp Level Controller and A field level controller, 1. An electrolytic cell system comprising: Each of said modular blocks comprises: electrolysis modules each comprising an electrolysis stack including a plurality of solid oxide electrolysis cells configured to receive steam in combination with hydrogen, a steam recycle outlet configured to recycle a portion of the steam, and an electrolysis module controller; a power module comprising a power converter configured to supply power to the electrolysis module and a power module controller configured to control the electrolysis module controller; Equipped with the stamp-level controller is configured to control the power module controller of the corresponding stamp; the site-level controller is configured to control the stamp-level controller and determine a stamp-level hydrogen generation demand for each stamp based on the received site-level hydrogen requirements; each said stamp level controller is configured to calculate a block level hydrogen generation demand for each modular block of a corresponding stamp based on the stamp level hydrogen generation demand received from the site level controller; each said power module controller is configured to calculate an electrolysis-level hydrogen generation demand for each electrolysis module of a corresponding modular block based on the block-level hydrogen generation demand received from the corresponding said power module controller; Electrolyzer system.

2. An electrolyzer system as described in claim 1, further comprising a hydrogen compression and treatment system.

3. An electrolyzer system as described in claim 2, wherein the field level controller is configured to control the hydrogen compression and treatment system.

4. The electrolyzer system of claim 3, wherein the field level controller is configured to control the stamp level controller and the hydrogen compression and treatment system based on at least one of received customer commands, power availability data, or system safety signals.

5. An electrolyzer system as described in claim 1, wherein each of the electrolysis module controllers is configured to control a corresponding electrolysis stack to produce a predetermined amount of hydrogen in accordance with the electrolysis level hydrogen demand received from a corresponding power module controller.

6. The electrolysis module controller is configured to output an electrolysis module alarm signal to the corresponding power module controller; The power module controller is configured to output a summary of the received electrolysis module alarm signal to the corresponding stamp level controller; The stamp level controller is configured to output a summary of alarms received from the power module controller to the field level controller.

10. The electrolytic cell system of claim 1.

7. The electrolytic cell system of claim 1, wherein the power module controller, the stamp level controller, and the field level controller are connected to each other via Ethernet.

8. An electrolytic cell system as described in claim 1, wherein each stamp further comprises a gas distribution module configured to supply hydrogen to the electrolysis module when the system is started.

9. An electrolytic cell system as described in claim 8, wherein the gas distribution module further comprises a pressure detector, a heat detector, a gas safety shutoff device, and a purge gas distributor.

10. The electrolysis module controller is configured to calculate a module hydrogen production rate of the corresponding electrolysis module; the power module controllers are configured to calculate block level hydrogen production rates based on module hydrogen production rates received from corresponding electrolysis module controllers; the stamp level controller is configured to calculate a stamp level hydrogen production rate based on a module hydrogen production rate received from a corresponding power module controller; the on-site level controller is configured to calculate an on-site level hydrogen production rate based on the stamp level hydrogen production rate received from the stamp level controller; 10. The electrolytic cell system of claim 1.

11. An electrolytic cell system as described in claim 1, further comprising a field level safety controller configured to provide field safety data to said field level controller.

12. An electrolytic cell system as described in claim 11, wherein the field level controller is configured to control the stamp level controller based on the safety data provided by the field level safety controller.

13. An electrolytic cell system as described in claim 1, wherein each of the modular blocks is placed on a respective pad.

14. An electrolytic cell system as described in claim 13, wherein each of the electrolytic modules of each of the modular blocks is arranged in a separate cabinet on each of the pads.

15. An electrolytic cell system as described in claim 13, wherein the power modules in each of the modular blocks are located in a cabinet separate from the electrolytic modules on each of the pads.

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