Compressor integration and safe operation start up for atmospheric operation of soec systems

Abstract

A compressor for a solid oxide electrolytic cell (SOEC) system, wherein the system comprises one or more stamps for receiving hydrogen and outputting wet hydrogen, a heat exchanger or condenser configured to reduce the temperature of the wet hydrogen, a compressor configured to increase the pressure of the wet hydrogen, and a dryer configured to reduce the dew point of the wet hydrogen.

Description

Technology Field

[0001] Embodiments of the present invention generally relate to an electrolytic cell system comprising a solid oxide electrolytic cell (SOEC) and a method for operating the same. In particular, it relates to the integration of a compressor for atmospheric operation of the SOEC system and safe operation initiation. Background Technology

[0002] Solid oxide fuel cells (SOFCs) can operate as electrolyzer cells for generating hydrogen and oxygen, referred to as solid oxide electrolyzer cells (SOECs). In SOFC mode, oxide ions are transported from the cathode side (air) to the anode side (fuel), and the driving force is the chemical gradient of the partial pressure of oxygen across the electrolyte. In SOEC mode, a positive potential is applied to the air side of the cell, and oxide ions are transported from the fuel side to the air side. Because the cathode and anode are opposite between SOFCs and SOECs (i.e., the SOFC cathode is the SOEC anode, and the SOFC anode is the SOEC cathode), the SOFC cathode (SOEC anode) may be referred to as the air electrode and the SOFC anode (SOEC cathode) may be referred to as the fuel electrode below. During SOEC mode, water in the fuel stream is reduced (H2O + 2e → O2). 2- + H2) H2 gas and O 2- Forms ions, O 2- After being transported through the solid electrolyte, the ions are oxidized on the air side (O 2-O2) molecular oxygen is generated. Since the open-circuit voltage for an SOFC operating with air and wet fuel (hydrogen, reformed natural gas) is about 0.9 to 1 V (depending on moisture content), the positive voltage applied to the air-side electrode in SOEC mode raises the voltage of the cell to a typical operating voltage of 1.1 to 1.3 V.

[0003] Embodiments of the present invention relate to the integration of a compressor for atmospheric operation and safe operation start of an SOEC system, which substantially eliminates one or more problems caused by the limitations and disadvantages of related technologies.

[0004] Further features and advantages of the present invention will be described in the following description, and may become apparent in part from the description or be learned through the practice of the invention. Objects and other advantages of the present invention will be realized and achieved by structures specifically mentioned in the detailed description and claims, as well as in the accompanying drawings.

[0005] To achieve these and other advantages, and as embodied and extensively described according to the purpose of the present invention, the compressor integration and safe operation start for atmospheric operation of an SOEC system comprises a system, apparatus, method, and instruction for operating an SOEC system, wherein the compressor implements a recirculation flow, the suction is controlled by a pressure controller, and a feed and vent globe control valve upstream of the compressor enables a smooth transition of the electrolysis product gas to the compressor, and a high-speed operating ball valve of the compressor skid relieves the suction line pressure when the compressor operation is stopped.

[0006] It should be understood that the foregoing general description and the detailed description to be set forth below are all exemplary and illustrative and intended to provide further explanation of the claimed invention. Brief explanation of the drawing

[0007] The accompanying drawings, included to provide further understanding of the present invention and comprising part of this specification, serve to illustrate embodiments of the present invention and explain the principles of the present invention together with the detailed description. FIG. 1 illustrates an SOFC / SOEC modular system according to an exemplary embodiment of the present invention. FIG. 2 illustrates a large-scale site electrolytic cell system according to an exemplary embodiment of the present invention. FIG. 3 illustrates a large-site electrolytic cell system according to another exemplary embodiment of the present invention. FIG. 4 illustrates a compressor system according to an exemplary embodiment of the present invention. FIG. 5 illustrates an SOEC system according to an exemplary embodiment of the present invention. Specific details for implementing the invention

[0008] We will now refer to embodiments of the present invention in detail, examples of which are illustrated in the accompanying drawings. It should be understood that the foregoing general description and the following detailed description are all illustrative and do not limit the claimed invention.

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

[0010] The modular design of the SOFC / SOEC system (10) provides flexible system installation and operation. The modules allow for the expansion of power generation capacity installed as a single set of designs, stable power generation, flexibility in fuel handling, and flexibility in power output voltage and frequency. The modular design provides "always on" units with very high availability and stability, and offers improved maintenance and expansion means. The modular design also enables the use of available fuel and required voltage and frequency, which may vary depending on the customer and / or region.

[0011] The SOFC / SOEC modular system (10) comprises a housing (14) in which at least one of a generator module (12) (preferably a plurality of generator modules (12) also referred to as “SGM”), one or more fuel processing modules (16) (within the SOFC system), and one or more power control modules (18) (i.e., an electrical output referred to as a generator module or “SPM”) is disposed. In this exemplary embodiment, the power control module (18) may include, for example, a mechanism for converting DC to AC or AC to DC. For example, the system (10) may include any number of modules, such as, for example, 2 to 30 generator modules, 3 to 12 generator modules, 6 to 12 modules, or other large-scale site configurations of generator modules.

[0012] The exemplary system (10) of FIG. 1 includes any number of generator modules (12) (one row of six modules stacked laterally), one fuel processing module (16) (within the SOFC system), and one power control module (18) on the pad (20). The housing (14) may include a cabinet that accommodates each module (12, 16, 18). Alternatively, the modules (16 and 18) may be placed in a single cabinet. Although one row of generator modules (12) is shown, the system may include more than one row 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 accommodate one or more hot boxes (13). Each hot box includes one or more stacks or columns of fuel / electrolyzer cells, such as one or more stacks or columns of solid oxide fuel cells having ceramic oxide electrolytes separated by conductive interconnect plates (not shown for clarity). Other fuel cell types, such as PEM, molten carbonate, phosphoric acid, etc., may also be used.

[0014] The fuel cell stack may include an external and / or internal manifold stack. For example, the stack may be internally manifolded for fuel and air, with a fuel and air riser extending through an opening in an interconnection plate between the fuel / electrolyzer cell layer and / or the fuel / electrolyzer cell.

[0015] The fuel / electrolyzer cell stack may be manifolded internally for fuel and externally for air, wherein fuel inlet and exhaust risers extend within interconnection plates between fuel cells and / or through openings within the fuel / electrolyzer cell layers. The fuel / electrolyzer cell may have a cross-flow configuration (where air and fuel flow nearly perpendicularly to each other on opposite sides of the electrolyte in each fuel cell), counter-flow parallel configuration (where air and fuel flow nearly parallel to each other but in opposite directions on opposite sides of the electrolyte in each fuel cell), or parallel flow parallel configuration (where air and fuel flow nearly 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 control module (18) may be housed in a single cabinet of the housing (14). As illustrated in the exemplary embodiment of FIG. 1, a single cabinet (14) is provided for a row of six (or any number) generator modules (12) arranged linearly side by side on one side of the input / output module (14). The row of modules must be located, for example, adjacent to a building to which the system provides power (e.g., the rear of the cabinet of the modules faces the building wall).

[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 demand of a building or other facility serviced by the fuel / electrolyzer cell system (10). Generator modules (12) and input / output modules (14) may also be provided in different ratios. For example, in other exemplary embodiments, more or fewer generator modules (12) may be provided adjacent to input / output modules (14). Additionally, support functions may be provided by more than one input / output module (14) (e.g., having separate fuel processing module (16) and power regulation module (18) cabinets). Furthermore, the input / output module (14) may be located at the end of a row of generator modules (12), or in the center or at other locations of a row of generator modules (12).

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

[0019] For example, as described above, the system (10) may include a plurality of generator modules (12). When at least one generator module (12) goes offline (i.e., power is not generated by stacks in the hot box (13) within the offline module (12), the remaining generator modules (12), fuel processing modules (16), and power control modules (18) (or combined input / output modules (14)) do not go offline. Additionally, the fuel cell / electrolyzer system (10) may include one or more of each type of module (12, 14, 16, or 18). When at least one module of a specific type goes offline, the remaining modules of the same type do not go offline.

[0020] Accordingly, in a system comprising multiple modules, each module (12, 14, 16, or 18) can be electrically disconnected, removed from the fuel / electrolyzer cell modular system (10), and / or serviced or repaired without interrupting the operation of other modules in the system, and the fuel cell system can continue to generate electricity. The entire SOFC / SOEC modular system (10) does not need to be shut down if one fuel cell / electrolyzer stack in one hot box (13) malfunctions or goes offline for service.

[0021] FIG. 2 illustrates a large-site electrolytic cell system (200) according to an exemplary embodiment of the present invention.

[0022] A large-site electrolyzer system (200) includes a gas distribution module (“GDM”; 250) configured to supply starting hydrogen to a plurality of modular blocks (210, 220, 230, 240). SOEC and SOFC systems generally require fresh hydrogen gas for starting and shutting down. The gas distribution module (250) may further include a pressure detector, a heat detector, a gas safety shut-off valve, and a purge gas distributor.

[0023] As described above, each modular block includes, for example, one power module ("SPM") and one or more generator modules ("SGM"). Grouping modular blocks into a group of systems is called a stamp. Thus, the large-site electrolytic system (200) is a stamp. Since hydrogen is a combustible gas supplied to each SGM at pressure, a safe method is required to cut off the gas to the group of generator modules (SGM) when a safety event is detected. Therefore, the GDM (250) is configured to cut off the hydrogen supplied to the SGM when a safety event is detected. Safety designs such as pressure sensing, overpressure protection, and gas safety cutoff are easily applied within the electrolytic system (200) by the GDM (250) and / or the fuel processing module (e.g., 16). Additionally, a stamp level controller may be provided in the GDM (250).

[0024] The grouping of four modular blocks (210, 220, 230, 240) is an exemplary configuration, but this configuration is an efficient grouping for gas safety. Additionally, the grouping of four modular blocks (210, 220, 230, 240) is efficient for collecting hydrogen products within the service passage (260). Piping (261) within the service passage (260) is configured to collect hydrogen products for integration with the downstream compression system. Piping (261) is configured to prevent condensate from flowing back into the generator module (SGM). Condensate management also enables the use of various monitoring and control devices and piping returning to the water discharge outlet (or BOP1).

[0025] FIG. 3 illustrates a large site (e.g., a 10-megawatt system) electrolytic cell system (300) according to an exemplary embodiment of the present invention. As illustrated in FIG. 3, the electrolytic cell system (300) comprises a plurality of stamps (310, 320, 330, 340, 350, 360, and 370). Additionally, the electrolytic cell system (700) further comprises additional balance of plant (BOP) components, such as a water source (BOP1), a hydrogen product collector (BOP2) (e.g., including piping (261)), and a hydrogen compression and treatment (BOP3). The hydrogen compression and treatment (BOP3) is functionally configured to supply hydrogen under pressure to a gas distribution module (e.g., GDM (250)) of each individual stamp (310, 320, 330, 340, 350, 360, and 370). Therefore, the stamp structure can be repeated in large-scale site layouts that construct large-scale site installations using repeating components.

[0026] FIG. 4 illustrates a compressor system (400) according to an exemplary embodiment of the present invention.

[0027] As illustrated in FIG. 4, the compressor system (400) comprises one or more stamps (410) to which hydrogen is supplied by a manifold (430) (e.g., a product manifold for the site, or coupled to stored hydrogen). For example, hydrogen may be supplied to a gas distribution module (e.g., GDM (250) in FIG. 2) of one or more stamps (410). The compressor system (400) further comprises a closed feedback loop from one or more stamps (410) through a heat exchanger or condenser (411), a switching valve (412), an isolation valve (413), a suction knockout drum (421), a compressor (422), a compressor skid drying system (425) (e.g., a dryer), and a gas analyzer (420). In various configurations, there may be one compressor (422) per stamp, or one compressor (422) for multiple stamps (410).

[0028] One or more stamps (410) supply wet hydrogen (e.g., a combination of steam and hydrogen) to a heat exchanger or condenser (411). The heat exchanger or condenser (411) reduces the output temperature of one or more stamps (410) to a temperature suitable for intake by a compressor (422) (e.g., cooled by 40°C to 80°C so that 150°C at the stamp output is cooled to 70°C to 110°C). In some cases, the product temperature supplied to the compressor (422) can be as high as 230°C.

[0029] The switching valve (412) is used to fully operate one or more stamps (410) and the compressor (422). Before the compressor (422) is fully operated and while one or more stamps (410) are fully operated, the output of the condenser (411) is exhausted by opening the switching valve (412A). Once the compressor (422) is fully operated, at 100% recirculation, the output of the condenser (411) is supplied to the suction knockout drum (421) by opening the switching valve (412B) and closing the switching valve (412A).

[0030] An isolation valve (413) (e.g., a high-speed pneumatic ball valve) is used when a fault event occurs (e.g., when excess pressure is detected). For example, if excess pressure is detected, the isolation valve (413A) may be opened. The isolation valve (413B) is opened during the operation of the compressor (422). Thus, excessive pressure is not fed back to one or more stamps (410) that could be damaged due to excessive pressure accumulation.

[0031] The suction knockout drum (421) is configured to collect and dispose of any condensate formed through a condensate discharge line (not shown). The suction knockout drum (421) is also configured to regulate any pressure fluctuations.

[0032] The compressed (i.e., increased pressure) output of the compressor (422) is further dried by the compressor skid drying system (425). A gas analyzer (420) monitors and controls the output of the compressor skid drying system (425) (i.e., dried gas) to maintain a target dew point, target nitrogen content, and / or target oxygen content. For example, the gas analyzer (420) may be configured to include a dew point sensor and one or more gas chromatographs. The gas analyzer (420) ensures that the output of the compressor skid drying system (425) (i.e., dried gas) meets one or more purity requirements (e.g., moisture and gas content) before being supplied to the manifold (430) (e.g., customer product line). The gas analyzer (420) can control the compressor skid drying system (425) to adjust the dew point (i.e., moisture). However, if one or more impurities (e.g., nitrogen or oxygen) exceed their respective thresholds, a warning signal or a shutdown signal may be transmitted to a system controller (not shown).

[0033] The regulator (426) is a back pressure regulator. When the system (400) starts, a minimum pressure is required for the compressor (422) and the compressor skid drying system (425). Otherwise, the compressor (422) and the compressor skid drying system (425) may be slow to generate sufficient pressure for operation. The regulator (416) is a forward pressure regulator. The product compressed in the regulator (416) can have a wide range of pressures (e.g., between 5 PSI and 10,000 PSI). Before being supplied to the pressure controller (415), the pressure output from the regulator (416) is adjusted (e.g. to less than 100 mbar). The pressure controller (415) is configured to measure the pressure in the suction knockout drum (421) and maintain the pressure in the suction knockout drum (421) by maintaining the pressure in the supply to the suction knockout drum (421) (e.g., less than 100 mbar). In some embodiments, the suction knockout drum (421) is optional.

[0034] Accordingly, various embodiments of the present invention relate to controlling the integration and initiation of a hydrogen-generating SOEC system and a compressor system.

[0035] When in operation, the operating SOEC system generates hydrogen at very low pressures, such as atmospheric pressure or just above atmospheric conditions (e.g., about 40 mbar). Due to these low pressures, minor fluctuations in downstream processes, such as compressor or valve switching, can cause immediate pressure / vacuum surges, which can lead to failure in the SOEC stack. Accordingly, various embodiments provide a technology that enables the compressor to be switched on without generating such surges, enables a smooth transition to the compressor, and provides a safe means of switching from compression to ventilation under shutdown conditions.

[0036] Others have used pressure switches to operate the compressor. In this case, hydrogen from the product is supplied to the compressor inlet. When a pressure threshold is reached, the compressor turns on. This has been used in low-temperature PEM and alkaline systems, which have a fast response under cold start conditions and can rapidly react to pressure fluctuations caused by compressor startup. SOEC systems are generally slower, and the examples utilize unreacted vapor during startup to prevent pressure spikes or vacuum in the compressor.

[0037] Others have used large inverted buckets as a means of balancing pressure in conjunction with the aforementioned pressure switch concept. This suggests the possibility of an open system where hydrogen and air can be mixed. Inverted buckets are also very large and occupy significant space.

[0038] In various embodiments, the disadvantages of the known technology are resolved. First, a 100% recirculation flow is implemented in a compressor (422) whose suction is controlled by a pressure controller (415). The pressure controller (415) maintains the suction pressure set in the compressor (422) regardless of the electrolytic hydrogen flow rate. Second, a switching valve (412) (e.g., supply and ventilation globe control valve) is implemented upstream of the compressor (422) to the compressor (422) to smoothly switch the electrolytic product gas to the compressor (422). In the event that the compressor (422) stops or a failure event occurs (immediately, e.g., within 2 or 3 seconds), isolation valves (413) (e.g., high-speed operating ball valve) on the compressor skid are used to relieve the suction line pressure.

[0039] The embodiment differs from known techniques that allow the SOEC system to be stabilized before the compressor is turned on. In addition, stack sensitivity issues regarding pressure surges that may occur due to the starting or stopping of the compressor unit are prevented.

[0040] FIG. 5 illustrates an SOEC system (500) according to an exemplary embodiment of the present invention.

[0041] As illustrated in FIG. 5, the SOEC system (100) includes: an air conduit (105), an air blower (106), an air inlet (107), a steam conduit (110), a recirculating steam inlet (111), a hot box (150), an optional hydrogen conduit (130), a concentrated air outlet (123), a concentrated air conduit (125), a concentrated air blower (126), a steam and hydrogen product outlet (120), a splitter (160), a venturi flow meter (165), a steam recirculating blower (170), and a heat sensor (175).

[0042] According to an exemplary configuration and operation, the steam input in the steam conduit (110) (e.g., supply site or facility steam of various pressures) may have a temperature of about 100°C to 110°C (e.g., 105°C) and a pressure of about 1 psig. In various embodiments, steam may be input into the SOEC system (500) from an external source or may be generated locally. In some embodiments, a plurality of steam inlets may each be configured to receive external and local steam. Alternatively or additionally, water may be input into the SOEC system (500) and vaporized.

[0043] The air input (e.g., ambient air) in the air conduit (105) may be an ambient temperature between approximately -20°C and +45°C at local atmospheric pressure. The air from the air conduit (105) is received by the air blower (106), and the air output by the air blower (106) will be slightly higher than the ambient temperature due to the heat of compression. For example, the temperature of the air output by the air blower (106) may be approximately 30°C at 1.0 psig compared to the ambient air temperature of 20°C. The air intake of the air conduit (105) is received at the air inlet (107) of the hot box (150).

[0044] Hydrogen from the optional hydrogen conduit (130) may be required only during startup and transient states when hydrogen is not otherwise generated by the SOEC system (500). For example, a separate hydrogen feed stream or hydrogen recirculation steam is no longer required in normal conditions. The pressure for this hydrogen stream is a design option determined at site construction and may be between about 5 psig and 3000 psig. The temperature is likely close to ambient temperature because it is likely to be in storage conditions.

[0045] Air input from the air conduit (105), steam input from the steam conduit (110), and hydrogen input from the optional hydrogen conduit (130) are input to the hot box (150). Eventually, the hot box (150) outputs steam and hydrogen product H2-H2O-G from the steam and hydrogen product discharge port (120) of the hot box (150), where G represents Gross. The hot box output H2-H2O-G may have a temperature of about 500°C to 180°C (e.g., 130°C) and a pressure of about 0.1 to 0.5 psig.

[0046] Additionally, the hot box output H2-H2O-G is input to a splitter (160) and split into a vapor recirculation stream RECH2OLP (where LP indicates low pressure) and a net product H2-H2O-N (where N indicates Net) (e.g., output for commercial use or storage). Here, the net product H2-H2O-N may have a temperature between about 100°C and 180°C (e.g., 130°C) and a pressure between about 0.1 psig and 0.5 psig. The vapor recirculation stream RECH2OLP may have a temperature between about 100°C and 180°C (e.g., 130°C) and a pressure between about 0.1 psig and 0.5 psig. The hot box (150) can further output concentrated air from a concentrated air outlet (123) through a concentrated air conduit (125) which can essentially have a temperature of about 120°C to 300°C at local atmospheric pressure (e.g., less than 0.5 psig or less than 0.05 psig).

[0047] The steam recirculation stream RECH2OLP is fed into a steam recirculation blower (170). The generated recirculation steam REC-STM may 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 fed into a hot box (150) from a recirculation steam inlet (111). In some embodiments, there may be no recirculation hydrogen feed contained in the recirculation steam.

[0048] As can be seen from FIG. 5, the inflow steam temperature (e.g., 105°C) in the steam conduit (110) is lower than that of an SOEC configuration with internal steam generation. In various configurations, multiple recirculation loops can be formed in the SOEC system using both internal steam generation and external steam generation. As illustrated, the recirculation steam inlet (111) is configured to receive steam from the steam conduit (110). Here, the embodiment optionally routes the facility supply steam from the steam conduit (110), which is typically saturated at a temperature of about 105°C, through internal steam generation coils, one or more vaporizers and / or other heating elements, and uses air exhaust heat (e.g., ~280°C) to further heat (i.e., superheat) the steam supply before the heat is released from the concentrated air conduit (125) through an optional fan or concentrated air blower (126).

[0049] In some embodiments, a customer (e.g., user, operator, or their computer) can control a solid oxide electrolytic cell (SOEC) system. One or more interfaces provide customized communication protocols (e.g., via Ethernet, the Internet, fixed wiring, etc.) to receive and execute customer commands to operate various states of the SOEC. Thus, the embodiments provide support to meet customer requirements for renewable hydrogen utilization while ensuring the safe operation of the SOEC.

[0050] For example, the embodiments allow a customer or another third party to control the SOEC system using parameters such as hydrogen generation, power limiting, and available steam. In some embodiments, a system is provided that can transition to a safe standby state in the event of a communication failure. Additionally, the safe standby state can be defined according to conditions agreed upon with the customer.

[0051] Additionally or alternatively, the embodiments provide one or more mechanisms to ensure that hydrogen generation meets customer requirements by enabling the customer to operate the SOEC system, providing safety logic to maintain operation within safe limits, and enabling hydrogen generation ramping. In some cases, the customer may receive advance notification of scheduled site limitations (e.g., unavailability of external hydrogen, available power schedule, communication restrictions to power storage, water and input hydrogen storage restrictions, etc.). Thus, the customer can adjust to these limitations (e.g., adjusting hydrogen generation based on hydrogen usage or hydrogen storage restrictions at the site).

[0052] It will be apparent to those skilled in the art that various modifications and changes may be made to the compressor integration and safe operation start for the atmospheric operation of the SOEC system of the present invention without departing from the spirit or scope of the present invention. Accordingly, the present invention is intended to include modifications and changes of the present invention within the scope of the appended claims and their equivalents.

Claims

Claim 1 A solid oxide electrolyzer cell (SOEC) system comprising: stacks of electrolyzer cells and generator modules that receive steam and output a hydrogen product including hydrogen and steam; a heat exchanger or condenser configured to cool the hydrogen product output from the generator modules; a compressor configured to pressurize the hydrogen product output from the heat exchanger or condenser; a dryer configured to reduce the dew point of the hydrogen product output from the compressor; switching valves configured to control the amount of the hydrogen product output from the generator modules that is exhausted and the amount supplied to the compressor based on the operating state of the compressor; and isolation valves configured to relieve the suction line pressure between the compressor and the generator modules in response to a failure event of the compressor; wherein the switching valves include: a first globe valve configured to control the exhaust of the hydrogen product; and a second globe valve configured to control the flow of the hydrogen product from the heat exchanger or condenser to the compressor; and wherein the isolation valves include: a first pneumatic valve configured to control the exhaust of the hydrogen product; A system comprising a second pneumatic valve configured to control the flow of the hydrogen product from the heat exchanger or condenser to the compressor. Claim 2 A system according to claim 1, further comprising a suction knockout drum configured to maintain the pressure of the hydrogen product supplied to the compressor. Claim 3 In paragraph 2, the system is configured such that the suction knockout drum is configured to remove water from the hydrogen product. Claim 4 A system according to claim 1, wherein when the compressor is not fully operating and when the generator modules are fully operating, the system is configured to open the first globe valve to exhaust the hydrogen product. Claim 5 A system according to claim 1, wherein when the compressor and the generator modules are fully operating, the system is configured to close the first globe valve and open the second globe valve so that all of the hydrogen product is supplied to the compressor. Claim 6 A system according to claim 1, further comprising a gas analyzer configured to detect the composition of the hydrogen product output from the dryer. Claim 7 In paragraph 6, the system is configured such that the gas analyzer controls the operation of the dryer based on the detected composition. Claim 8 A system according to claim 1, further comprising a manifold configured to supply hydrogen to the generator modules. Claim 9 A method for operating a solid oxide electrolyzer cell (SOEC) system comprises: operating generator modules including stacks of electrolyzer cells to produce a hydrogen product including hydrogen and steam; cooling the hydrogen product in a heat exchanger or condenser to produce a cooled hydrogen product; compressing the cooled hydrogen product output from the heat exchanger or condenser in a compressor to produce a compressed hydrogen product; drying the compressed hydrogen product output from the compressor in a dryer to produce a dried hydrogen product; operating isolation valves to relieve suction line pressure between the compressor and the generator modules in response to a failure event of the compressor; and operating switching valves to control the amount of the cooled hydrogen product exhausted and the amount supplied to the compressor based on the operating state of the compressor or the operating state of the generator modules; wherein the switching valves include: a first globe valve configured to control the exhaust of the hydrogen product; A method comprising a second globe valve configured to control the flow of the hydrogen product from the heat exchanger or condenser to the compressor, wherein the isolation valves include: a first pneumatic valve configured to control the exhaust of the hydrogen product; and a second pneumatic valve configured to control the flow of the hydrogen product from the heat exchanger or condenser to the compressor. Claim 10 A method according to claim 9, further comprising the step of providing hydrogen to the generator modules during the start-up and shutdown of the generator modules. Claim 11 A method according to claim 9, further comprising the step of maintaining the pressure of the cooled hydrogen product supplied to the compressor using a suction knockout drum. Claim 12 A method according to claim 11, further comprising the step of providing a controlled flow of the cooled hydrogen product to the suction knockout drum. Claim 13 A method according to claim 9, further comprising the step of detecting the composition of the dried hydrogen product output from the dryer; and the step of controlling the dryer based on the detected composition. Claim 14 In claim 9, the isolation valves are operated to relieve the suction line pressure between the compressor and the generator modules within 3 seconds of a failure event of the compressor. Claim 15 delete Claim 16 delete Claim 17 delete Claim 18 delete

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