System for rebalancing pressure difference in a fuel cell using gas injection

Abstract

A fuel cell system includes a fuel cell module (100) having an anode with an anode inlet configured to receive an anode feed gas and an anode outlet (121) configured to output an anode exhaust to an anode exhaust conduit (120). The fuel cell module further includes a cathode having a cathode inlet configured to receive a cathode feed gas and a cathode outlet. The fuel cell system also includes an anode exhaust treatment system (105) fluidly coupled to the anode exhaust conduit (120) and a gas injection system (115) disposed downstream of the anode inlet and upstream of the anode exhaust treatment system (105). The gas injection system (115) is configured to inject a gas within the anode exhaust conduit to prevent under-pressurization of the anode.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit and priority of U.S. Patent Application No. 63 / 042,355, filed June 22, 2020, the entire disclosure of which is hereby incorporated by reference. Background Technology

[0003] This application generally relates to the field of fuel cell systems, and more specifically, to systems for balancing pressure differences within a fuel cell.

[0004] Generally speaking, a fuel cell comprises an anode (negative electrode) and a cathode (positive electrode), separated by a conductive electrolyte that facilitates ion exchange between them. The fuel cell generates electricity when the anode and cathode are supplied with fuel and oxidant, respectively. An airflow field adjacent to each of the anode and cathode facilitates the supply of fuel and oxidant. To increase the generated power, individual fuel cells can be stacked in series, with conductive spacers positioned between each fuel cell and its adjacent cells. During operation, the gas pressure on the anode side of the fuel cell stack needs to be maintained close to the gas pressure on the cathode side. In fuel cell systems, blowers with variable frequency drives and speed controllers in the anode exhaust stream are typically used to maintain the anode pressure close to the cathode pressure. This is especially true in fuel cell systems with anode exhaust stream treatment, which may include water recovery, a chemical shift reactor, and / or an anode exhaust outlet leading to an external system.

[0005] Pressure balance means that the anode pressure and cathode pressure are nearly identical, with a water column difference within a few inches. During periods of abnormal system operation, such as when the power output of the fuel cell decreases or increases rapidly, pressure imbalance occurs due to the instantaneous decrease or increase in the volumetric flow rate of the fuel cell anode exhaust. However, the anode blower typically needs a few seconds to reduce or increase its speed to compensate for the decrease or increase in anode exhaust. During this delay, the anode exhaust flow rate supplied to the anode blower is insufficient relative to the flow rate drawn into the anode blower in the case of power reduction, or excessive relative to the flow rate drawn into the anode blower. This sudden difference in flow rate results in a decrease or increase in pressure in the anode relative to the pressure in the cathode (i.e., insufficient or excessive anode pressurization). Insufficient or excessive anode pressurization can be severe enough to damage the fuel cell, typically by damaging the fuel cell manifold and / or fuel cell manifold seals.

[0006] In some fuel cell manifold designs, insufficient anode pressurization, exceeding -7 inches of water column pressure (iWC), measured as the pressure difference between the anode and cathode, is considered potentially damaging to the fuel cell. Insufficient pressurization exceeding -10 iWC is considered highly likely to cause fuel cell damage, and insufficient pressurization exceeding -15 iWC is extremely likely to cause fuel cell damage. Fuel cell damage may be limited to the fuel cell manifold and manifold seals. In cases of insufficient anode pressurization, manifold collapse can lead to more severe damage, causing mechanical damage to additional components of the fuel cell (e.g., internal fuel delivery systems, or affecting the cell itself, including short-circuiting). Repairing damage caused by insufficient pressurization can be extremely expensive, sometimes exceeding the value of the fuel cell itself.

[0007] Therefore, it may be advantageous to provide a system for rebalancing pressure differentials in a fuel cell to mitigate or avoid excessive pressure differentials between the anode and cathode and reduce the risk of damage to the fuel cell. The systems and methods described in the exemplary embodiments discussed herein are configured to reduce or eliminate insufficient anode pressurization in response to changes in pressure differentials within the fuel cell by injecting pressurized gas into the anode exhaust pipe. Summary of the Invention

[0008] One aspect of this disclosure relates to a fuel cell system. The fuel cell system includes a fuel cell module comprising an anode having an anode inlet configured to receive anode feed gas and an anode outlet configured to output anode exhaust gas to an anode exhaust duct. The fuel cell module further includes a cathode having a cathode inlet configured to receive cathode feed gas and a cathode outlet. The fuel cell system further includes an anode exhaust treatment system fluidly coupled to the anode exhaust duct and a gas injection system disposed downstream of the anode outlet and upstream of the anode exhaust treatment system, wherein the gas injection system is configured to inject gas into the anode exhaust duct to prevent underpressurization of the anode.

[0009] In various embodiments, the gas injection system includes at least one tank in fluid communication with a gas supply source, the at least one tank being configured to provide a flow rate of the gas to the anode exhaust duct. In some embodiments, the at least one tank includes a first tank and a second tank, the first tank being directly coupled to the gas supply source and the second tank being configured to receive the gas from the first tank, wherein the flow rate of the gas from the first tank to the second tank is metered by a first valve. In other embodiments, the pressure within the at least one tank is maintained at a predetermined set value based on the operating conditions of the fuel cell system. In various embodiments, the gas injection system is configured to inject the gas in response to a determination that a pressure difference exceeds a predetermined threshold. In some embodiments, the gas injection system is configured to inject gas based on operating parameters associated with the fuel cell module.

[0010] In various embodiments, the fuel cell system further includes an anode exhaust gas recirculation system fluidly connected downstream of the anode exhaust gas treatment system, the anode exhaust gas recirculation system being configured to recirculate anode exhaust gas from the anode exhaust gas treatment system back to the anode exhaust gas duct. In some embodiments, the anode exhaust gas recirculation system is configured to operate in conjunction with the gas injection system, wherein the anode exhaust gas recirculation system is configured to operate in series with the gas injection system. In yet another embodiment, the fuel cell system includes a first lift valve disposed within a first path fluidly connected between the anode exhaust gas recirculation system and the gas injection system. In various embodiments, the first lift valve is fluidly connected in series with at least one other valve configured to allow flow through the anode exhaust gas recirculation system. In some embodiments, the fuel cell system further includes a second valve disposed within a second fluid path fluidly connected between the anode exhaust gas recirculation system and the gas injection system, wherein at least one of the first valve or the second valve is fluidly connected in series with a pressure transmitter, and wherein an output from the pressure transmitter instructs at least one of the first valve or the second valve to automatically open in the event of a failure. In other embodiments, the fuel cell system includes a water seal system in fluid communication with the fuel cell module and configured to prevent overpressurization of the anode. In various embodiments, the at least one other valve is a solenoid valve.

[0011] Another aspect of this disclosure relates to a method for rebalancing pressure within a fuel cell system. The method includes: determining a pressure difference between an anode outlet and a cathode inlet via a pressure differential transmitter, the anode outlet and cathode inlet being contained within a fuel cell module; and injecting gas into an anode exhaust duct from an injection path via a gas injection system in fluid communication with the anode outlet of the fuel cell system. The anode exhaust duct is fluidly connected to the anode outlet and an anode exhaust treatment system, wherein the injection path is located downstream of the anode outlet and upstream of the anode exhaust treatment system, and wherein injecting the gas into the anode exhaust duct causes pressure rebalancing between the anode outlet and the cathode inlet.

[0012] In various embodiments, the gas injection into the anode exhaust duct is performed in anticipation of potential pressure variations within the fuel cell module. In some embodiments, injecting the gas into the anode exhaust duct includes receiving inert gas from a supply source at a receiver tank, wherein peak flow rates of the gas from the supply source to the receiver tank are limited to limit peak demand on the supply source. In other embodiments, the method further includes recirculating anode exhaust from the anode exhaust treatment system to the anode exhaust duct via an anode exhaust recirculation system. In some embodiments, the recirculation of the anode exhaust is delayed so that it is injected later than the gas from the injection path.

[0013] Another aspect of this disclosure relates to a method for rebalancing pressure within a fuel cell system, the method comprising: sensing a first pressure within an anode outlet conduit fluidly connected to an anode outlet of a fuel cell module via a first pressure sensor, wherein the first pressure sensor is in communication with a differential pressure regulator. The method further comprises: sensing a second pressure at a cathode inlet included within the fuel cell module via a second pressure regulator, wherein the second pressure sensor is in communication with the differential pressure regulator; and allowing gas to flow through the differential pressure regulator into an injection path, wherein the gas flows into the injection path and enters the anode exhaust conduit. The gas entering the anode exhaust conduit causes a pressure rebalancing between the anode outlet and the cathode inlet.

[0014] In various embodiments, the method further comprises recirculating anode exhaust from the anode exhaust treatment system to the anode exhaust duct via an anode exhaust recirculation system in fluid communication with the anode outlet duct. In some embodiments, the gas is an inert gas.

[0015] The content of this invention is illustrative only and should not be considered restrictive. Attached Figure Description

[0016] The advantages and features constituting this disclosure, as well as the construction and operation of typical mechanisms provided with this disclosure, will become more apparent from the exemplary and therefore non-limiting embodiments illustrated in the accompanying drawings and forming part of this specification, wherein similar reference numerals denote the same elements in multiple views, and in the drawings:

[0017] Figure 1 This is a schematic representation of a fuel cell system including a gas injection system with an active control valve, according to an exemplary embodiment.

[0018] Figure 2 This is a schematic representation of a fuel cell system including a gas injection system with a passive control valve, according to an exemplary embodiment.

[0019] Figure 3 This is a schematic representation of a fuel cell system that includes a gas injection system and also has an optional anode recirculation and liquid level regulating water seal system, according to an exemplary embodiment.

[0020] Figure 4 This is a schematic representation of a gas injection system having an active control valve used in conjunction with an anolyte gas recirculation system, according to an exemplary embodiment, wherein simultaneous actuation of the anolyte gas recirculation and the gas injection system is passively prevented.

[0021] Figure 5 This is a schematic representation of a gas injection system having an active control valve used in conjunction with an anolyte gas recirculation system, according to another exemplary embodiment, wherein simultaneous actuation of the anolyte gas recirculation and the gas injection system is passively prevented.

[0022] Figure 6 This is a schematic representation of a gas injection system with an active control valve according to another exemplary embodiment.

[0023] The foregoing and other features of this disclosure will become apparent from the following description and the appended claims in conjunction with the accompanying drawings. It should be understood that these drawings depict only a few embodiments according to this disclosure and are therefore not intended to limit the scope of the disclosure, which will be described with additional features and details using the drawings. Detailed Implementation

[0024] Various embodiments of this disclosure relate to a gas injection system comprising a gas injection tank containing pressurized gas, the gas injection tank being in fluid communication with an anode exhaust pipe within the anode of a fuel cell. The gas injection tank may be isolated from the anode exhaust pipe and metered via a controllable valve actuated in response to changes in pressure differentials within the fuel cell (e.g., changes in pressure differential between the anode and cathode chambers). According to various embodiments, the controllable valve may be actuated at varying rates and / or for varying durations to meter the gas injected from the gas injection tank into the anode exhaust pipe.

[0025] In various embodiments, the gas injection system may be configured as part of a passive pressure control system within the fuel cell system, wherein the actuation of the gas injection system is passively actuated in response to a pressure difference within the fuel cell system.

[0026] In various embodiments, the pressurized gas may include, but is not limited to, nitrogen, carbon dioxide and / or other inert or reducing gases.

[0027] In various embodiments, mitigation of pressure differential variations between the anode and cathode can be based on the volume and / or flow rate of the injected gas, wherein the volume and / or flow rate of the injected gas can further depend on the volume of the gas injection tank, the pressure within the gas injection tank, losses in the gas injection pipeline, valve flow area, and / or valve opening speed.

[0028] In various embodiments, the gas injection tank is in fluid communication with the main gas supply source via a tank filling line and includes a controllable tank filling valve to facilitate maintaining the gas injection tank pressure. In various embodiments, the tank filling line may be in fluid communication with one or more receiver tanks, which allows for rapid refilling of the gas injection tank and reduces the need for the main gas supply source.

[0029] In various embodiments, the gas injection tank is in fluid communication with a vent line having a controllable vent valve, which facilitates the removal of gas from the gas injection tank (e.g., release into the atmosphere). In various embodiments, the pressure within the gas injection tank can be regulated and maintained at a pressure setpoint via control of the tank filling valve and / or vent valve. In various embodiments, the pressure setpoint is adjusted based on one or more operating conditions of the fuel cell power generation device comprising the fuel cell system.

[0030] In various embodiments, in addition to the water seal system, the gas injection system may also be in fluid communication with the fuel cell system, wherein the gas injection system is configured to alleviate insufficient anode pressure, while the water seal system is configured to alleviate anode overpressure.

[0031] In various embodiments, in addition to one or more anode recirculation valves, the gas injection system may also be in fluid communication with the fuel cell system, and each of one or more anode recirculation valves is configured to work with the gas injection system to help alleviate insufficient anode pressurization.

[0032] In various embodiments, when the gas injection system is used in conjunction with one or more anode recirculation valves, the lift valve system is configured to passively prevent the anode recirculation valves from being actuated until the gas injection system has substantially completed gas injection.

[0033] Referring generally to the accompanying drawings, a fuel cell system includes at least one fuel cell (having an anode and a cathode) and an anode exhaust treatment system fluidly coupled thereto, wherein the anode exhaust output from the fuel cell is treated and / or converted for use at an output or at other locations within the fuel cell system. In various embodiments, the anode exhaust treatment system may cool the anode exhaust, react with the anode exhaust, and / or separate one or more components (e.g., byproducts) from the anode exhaust. The fuel cell system may include an anode exhaust blower that receives the treated anode exhaust (e.g., a treated stream from the anode exhaust treatment system) and may be configured to maintain the anode pressure within a range comparable to the cathode pressure. The anode exhaust blower may be communicatively coupled to a controller and / or a pressure sensor, wherein at least one of the pressure sensor and the controller is configured to measure the difference between the anode and cathode pressures and, in response, cause speed regulation of the anode exhaust blower to maintain a predetermined and / or desired pressure difference. A fuel cell system may include one or more pressure rebalancing systems to minimize, mitigate, or eliminate the pressure difference between the anode and cathode, which may be greater than or less than a predetermined and / or desired pressure difference, and thus to prevent potential damage within the fuel cell system (e.g., damage to the fuel cell itself, damage to the fuel cell manifold, and / or damage to the fuel cell manifold gaskets). In various embodiments, the pressure difference may be greater than or less than the predetermined and / or desired pressure difference due to a sudden decrease or increase in fuel cell output, a failure of the anode exhaust blower, and / or an anomaly in the anode exhaust treatment system.

[0034] In various embodiments, the fuel cell system may include a gas injection system for minimizing or eliminating anode pressure insufficiency within the fuel cell system. The gas injection system includes a gas injection tank containing pressurized gas, which is in fluid communication with an anode vent line within the anode compartment of the fuel cell. The gas injection tank is isolated from the anode vent line by a controllable valve actuated in response to changes in pressure differentials within the fuel cell (e.g., changes in pressure differential between the anode and cathode chambers). The controllable valve can be actuated at different rates and for different durations to meter the gas injected from the gas injection tank into the anode vent line. Mitigation of pressure differential changes between the anode and cathode is based on the volume and / or flow rate of the injected gas, which further depends on the volume of the gas injection tank, the pressure within the gas injection tank, losses in the gas injection line, valve flow area, and / or valve opening speed. The pressure within the gas injection tank is typically maintained at a significantly higher pressure than that associated with the anode, and may be readily controllable and pre-set based on fuel cell operation. The flow rate, flow rate decay over time, and total amount of injected gas via orifices and / or valves associated with the gas injection tank are highly predictable, thereby improving overall control of pressure rebalancing operations within the fuel cell system.

[0035] In various embodiments, the gas injection tank may be fluidly connected to a main gas supply source via a tank filling line, which facilitates the injection of filling or refilling gas into the tank. Filling gas injection into the tank can be facilitated by a controllable tank filling valve. In various embodiments, the tank filling line may be fluidly connected to one or more receiver tanks, enabling rapid refilling of the gas injection tank and reducing peak (e.g., transient) demand on the main gas supply source. In various embodiments, the gas injection tank is fluidly connected to a vent line, whereby gas can be vented and released into the atmosphere. Gas flow through the vent line can be controlled by a vent valve. The pressure within the gas injection tank can be regulated and maintained at a pressure setpoint by controlling the tank filling valve and / or the vent valve. This pressure control scheme provides a faster refill rate than when the pressure is controlled via the tank filling valve. In various embodiments, the pressure setpoint is adjusted based on one or more operating conditions of a fuel cell power generation device including a fuel cell system.

[0036] Now for reference Figure 1The figure illustrates a fuel cell system 10 according to an exemplary embodiment, incorporating a system for rebalancing pressure differentials. As shown, the fuel cell system 10 includes a fuel cell module 100 in fluid communication with each of an anode exhaust treatment system 105, an anode exhaust blower 110 controlled by a controller 113, and an actively controlled gas injection system 115 configured to facilitate rebalancing pressure differentials, wherein fluid communication is facilitated via an anode exhaust conduit 120 (e.g., a duct). In various non-limiting embodiments, the fuel cell module 100 may be a molten carbonate fuel cell (MCFC) and may operate between approximately 550-650°C. In other embodiments, the fuel cell module 100 may comprise one or more fuel cells of any type known in the art, including other high-temperature, intermediate-temperature, or low-temperature fuel cell modules. In various embodiments, the fuel cell module may comprise one or more fuel cells arranged in a stack, wherein the stack may be configured in parallel and / or series.

[0037] Anode exhaust conduit 120 allows anode exhaust from fuel cell module 100 to exit via anode outlet 121 (e.g., at an anode exhaust manifold connected to anode outlet 121). Fuel cell module 100 includes at least one fuel cell and receives fuel gas via anode inlet 122 (e.g., at an anode inlet manifold connected to anode inlet 122). Fuel cell module 100 also includes cathode inlet 123 (e.g., at a cathode inlet manifold connected to cathode inlet 123 for receiving cathode feed gas) and cathode outlet 124. Anode inlet 122 may have an anode inlet pressure P1, where P1 can be defined as the pressure of the anode fuel gas at anode inlet 122. Cathode inlet 123 may similarly have a cathode inlet pressure P2, where P2 can be defined as the pressure of the cathode feed gas (“inlet gas”) at cathode inlet 123. Anode outlet 121 may have an anode outlet pressure P3, where P3 can be defined as the pressure of the anode exhaust at anode outlet 121.

[0038] The pressure difference that can be measured between P1 and P2 or between P3 and P2 can be determined using the differential pressure transmitter (PDT) 125. For example... Figure 1As shown, PDT 125 can be configured to measure the pressure difference between the anode outlet 121 (P3) and the cathode inlet 123 (P2) via gas pressure sensing lines 135 and 130, respectively. In various embodiments, PDT 125 can be configured to measure the pressure difference between P1 and P2 and / or P3 and P2. As previously described, a high pressure difference within the fuel cell module 100 can lead to damage within the fuel cell system 10. If the pressure associated with the cathode (e.g., the pressure at P2 and / or other fluid junctions) is greater than the pressure associated with the anode (e.g., the pressure at P1, P3 and / or other fluid junctions), the anode may be at risk of underpressurization. Conversely, if the pressure associated with the anode (e.g., the pressure at P1, P3 and / or other fluid junctions) is greater than the pressure associated with the cathode (e.g., the pressure at P2 and / or other fluid junctions), the anode may be at risk of overpressurization.

[0039] like Figure 1 As shown, the fuel cell system 10 includes an anode exhaust blower 110 configured to receive anode exhaust gas from an anode exhaust gas treatment system 105 (via anode exhaust gas duct 120). The anode exhaust gas treatment system 105 is configured to process the anode exhaust gas output from the anode outlet 121 of the fuel cell module 100. The anode exhaust gas received by the anode exhaust blower 110 (e.g., a processed stream) may then be output for further processing, collection, or output from the fuel cell system 10. The operating speed of the anode exhaust blower 110 is controlled by a controller 113 (“speed controller”) communicatively connected to it. The controller 113 is configured to maintain and / or regulate the speed of the anode exhaust blower 110 based on a pressure difference measured by a PDT 125 communicatively connected via a communication path 127. In various embodiments, the PDT 125 may communicate with the controller 113 via wired and / or wireless communication.

[0040] The fuel cell system 10 includes an actively controlled gas injection system 115 configured to facilitate pressure rebalancing, located between the anode outlet 121 and the anode exhaust treatment system 105. As previously described, insufficient anode pressure may occur if the controller 113 fails to adjust the speed of the anode exhaust blower 110 in a timely manner (based on the pressure difference measured by the PDT 125) according to flow or pressure fluctuations at the anode inlet, anode outlet, or cathode inlet. To prevent insufficient anode pressurization (i.e., underpressurization), the gas injection system 115 injects inert and / or reducing gases into a conduit (e.g., anode exhaust duct 120) in fluid communication with at least one of the anode inlet 122 and anode outlet 121. Figure 1As shown, the gas injection system 115 is configured to inject gas into the anode exhaust duct 120 via an injection path 165 located downstream of the anode outlet 121 and upstream of the anode exhaust treatment system 105.

[0041] The gas injection system 115 includes a gas injection reservoir 170 containing pressurized gas for injection into the fuel cell system 10. In various embodiments, the supplied gas may be nitrogen, carbon dioxide, and / or another inert or reducing gas. One or more high-speed opening valves 180 facilitate the injection of gas from the gas injection reservoir 170, and these valves can controllably allow or prevent gas flow into the injection path 165. In various embodiments, the injection of gas from the injection reservoir 170 is performed in response to an actuation signal received by a controller communicatively coupled to the gas injection system 115. In various embodiments, the actuation signal may be sent to the controller based on a determination that the pressure difference exceeds a predetermined threshold (e.g., by one or more additional controllers communicating with the PDT 125). The gas injection reservoir 170 is also in fluid communication with a vent line 183 configured to allow the release of gas from the gas injection reservoir 170 via a pressure control valve 185. Gas injection tank 170 may receive gas from receiver tank 190, wherein the flow rate from receiver tank 190 to gas injection tank 170 is measured by valve 195. Receiver tank 190 may correspondingly receive gas from gas supply source 197, wherein the flow rate from gas supply source 197 to receiver tank 190 is measured by valve 199. Receiver tank 190 may be configured to limit peak flow rates of gas (e.g., from gas supply source 197) and thus limit peak demand on gas supply source 197. Pressure within gas injection tank 170 is maintained by control valves 195 and / or 185. In various embodiments, gas injection tank 170 may be in direct fluid communication with gas supply source 197, allowing gas to flow directly from gas supply source 197 into gas injection tank 170. In various other embodiments, the gas injection system 115 may include a plurality of receiver tanks similar to or equivalent to receiver tank 190, each configured to receive gas from gas supply source 197 for final inflow into injection tank 170.

[0042] In various embodiments, the gas injection tank 170 may be maintained at a target pressure or pressure setpoint, wherein the target pressure and / or pressure setpoint may be based on the operating conditions of the fuel cell system 10 and / or the power generation equipment including the fuel cell system 10. The adjustability of the pressure within the gas injection tank 170 allows for precise control of the effect of gas injection on pressure differences within the fuel cell module (e.g., the pressure difference between P1 and P2, or between P3 and P2). In various embodiments, the gas injection tank 170 may be configured for rapid refilling to ensure preparedness for potentially recurring anode pressure deficiency events. In these embodiments, rapid refilling of the gas injection tank 170 may exceed a predetermined target pressure and / or pressure setpoint. When the pressure within the gas injection tank 170 exceeds the predetermined target pressure and / or pressure setpoint during rapid refilling, a pressure control valve 185 may open to facilitate the release of gas from the gas injection tank 170 (e.g., via vent line 183) and subsequently allow the gas injection tank to return to a predetermined desired pressure.

[0043] During operation, when a pressure change is detected (e.g., via PDT 125 or one or more pressure sensors within and / or near fuel cell module 100), particularly when the pressure associated with the anode within fuel cell module 100 (e.g., P1 and / or P3) is lower or decreased relative to the pressure associated with the cathode within fuel cell module 100 (e.g., P2), gas injection system 115 is configured to inject gas from gas injection tank 170 into anode exhaust duct 120 (and / or anode inlet 122). In various embodiments, fuel cell module 100, gas injection system 115, and / or PDT 125 may be communicatively coupled to one or more controllers, wherein one or more controllers may cause the gas injection system to inject gas in response to determination by PDT 125 that a pressure difference exceeds a predetermined pressure threshold. The injected gas then restores pressure balance within fuel cell module and thus within fuel cell system 10. In various embodiments, gas injection system 115 may be configured to inject gas from gas injection tank into anode inlet 122 and / or anode exhaust duct 120 based on one or more operating parameters associated with fuel cell system 10. In various embodiments, the gas injection system 115 may be configured to operate in response to anticipated pressure changes within the fuel cell module 100, enabling faster pressure rebalancing compared to reactive gas injection operations based on pressure differences measured at PDT 125. In various embodiments, the rate and / or volume of gas injected from the gas injection system 115 may be based on one or more operating parameters associated with the fuel cell system 10.

[0044] Figure 2A schematic representation of a fuel cell system 10 according to an exemplary embodiment is shown, which incorporates a passively controlled gas injection system 115. As shown, the fuel cell system 10 includes a fuel cell module 100 in fluid communication with each of an anode exhaust treatment system 105, an anode exhaust blower 110 controlled by a controller 113, and a passively controlled gas injection system 115 configured to facilitate rebalancing of the pressure differential, wherein fluid communication is facilitated via an anode exhaust conduit 120 (e.g., a duct).

[0045] like Figure 2 As shown, PDT 125 can be configured to measure the pressure difference between the anode outlet 121 (P3) and the cathode inlet 123 (P2) via gas pressure sensing lines 135 and 130, respectively. In various embodiments, PDT 125 can be configured to measure the pressure difference between P1 and P2 or between P3 and P2. As previously described, fuel cell system 10 includes an anode exhaust blower 110, which is configured to receive anode exhaust from anode exhaust treatment system 105 (via anode exhaust duct 120) and is controlled by a controller 113 (“speed controller”) communicatively connected to it. Controller 113 is configured to maintain and / or regulate the speed of anode exhaust blower 110 based on the pressure difference measured by PDT 125 communicatively connected via communication path 127.

[0046] The fuel cell system 10 includes a passively controlled gas injection system 115 configured to facilitate pressure rebalancing, located between the anode outlet 121 and the anode exhaust treatment system 105. As previously described, insufficient anode pressure may occur if the controller 113 fails to adjust the speed of the anode exhaust blower 110 in a timely manner (based on the pressure difference measured by the PDT 125). To prevent insufficient anode pressurization, the gas injection system 115 injects inert and / or reducing gases into a conduit (e.g., anode exhaust duct 120) in fluid communication with at least one of the anode inlet 122 and anode outlet 121. Figure 2 As shown, the gas injection system 115 is configured to inject gas into the anode exhaust duct 120 via an injection path 165 located downstream of the anode outlet 121 and upstream of the anode exhaust treatment system 105.

[0047] The gas injection system 115 includes a receiver tank 190 containing gas for injection into the fuel cell system 10. The receiver tank 190 receives gas from a gas supply source 197, with the flow rate from the gas supply source 197 to the receiver tank 190 measured by a valve 199. In various embodiments, the supplied gas may be nitrogen, carbon dioxide, and / or another inert or reducing gas. Gas injection from the receiver tank 190 is facilitated by one or more differential pressure regulators 200, which passively control the flow of gas into the injection path 165. As shown, the differential pressure regulators 200 can be actuated via gas pressure sensing lines 307 and 309 by pressures associated with the anode outlet 121 (e.g., P3) and pressures associated with the cathode inlet 123 (e.g., P2). In various embodiments, when the pressure at anode outlet 121 (e.g., P3) is a threshold amount lower than the pressure at cathode inlet 123 (e.g., P2), gas is injected from receiver tank 190. This may cause differential pressure regulator 200 to open, allowing gas to flow through and into injection path 165, where the gas subsequently enters anode exhaust duct 120. Once pressure rebalancing has been achieved (e.g., as determined from gas pressure sensing lines 307 and 309), differential pressure regulator 200 may then close and prevent further gas flow. In various embodiments, differential pressure regulator 200 may be in direct fluid communication with gas supply source 197, allowing gas to flow directly from gas supply source 197 into differential pressure regulator 200. In various other embodiments, gas injection system 115 may include multiple receiver tanks similar to or equivalent to receiver tank 190, each configured to receive gas from gas supply source 197 for eventual inflow into fuel cell system 10. In various embodiments, the passively controlled gas injection system 115 may also include a pressure-controlled injection tank (e.g., similar to or equivalent to tank 170) in fluid communication with the receiver tank 190.

[0048] In various embodiments, the gas injection system 115 may be configured to operate in conjunction with an anode exhaust gas recirculation system included within a fuel cell system (e.g., fuel cell system 10) to rebalance the pressure therein. In various exemplary embodiments, fuel cell system 10 may include an anode exhaust gas recirculation system 205, such as... Figure 3As shown, it is configured to operate in conjunction with the gas injection system 115 to provide pressure rebalancing and prevent anode underpressurization. In various embodiments, the exhaust gas recirculation system 205 is configured to facilitate the flow of treated anode exhaust gas (e.g., treated stream) back to a low-pressure gas path upstream of the anode exhaust blower 110 to mitigate or eliminate anode underpressurization. The exhaust gas recirculation system 205 may be fluidly coupled to the anode exhaust duct 120 via path 213 and may be configured to facilitate the flow of treated anode exhaust gas into the anode exhaust duct 120.

[0049] Figure 4 A schematic representation of an actively controlled gas injection system 115 configured to operate in series with an exhaust gas recirculation system 205 within a fuel cell system 10, according to an exemplary embodiment, is shown. In various embodiments, to prevent concurrent operation of the gas injection system 115 and the exhaust gas recirculation system 205 (which could lead to anode overpressure) instead of the desired series operation, the exhaust gas recirculation system 205 may be configured to operate only after the pressure within the gas injection tank 170 has decreased to below a threshold pressure. Delaying the operation of the exhaust gas recirculation system 205 until the pressure in the injection tank 170 is below the threshold pressure reduces the risk of excessive gas pressure (e.g., P1) in the anode inlet 122 and / or gas pressure (e.g., P3) in the anode outlet 121, and thus reduces the risk of anode overpressure. In various embodiments, the exhaust gas recirculation system 205 may be configured to operate based on the pressure within the receiver tank 190.

[0050] As shown in the figure, the gas injection system 115 is in fluid communication with the exhaust gas recirculation system 205 via a fluid communication path 215. The gas injection system 115 includes a high-speed opening valve 180, which facilitates the injection of gas from the injection tank 170 into a flow path 165, wherein the flow path 165 is in fluid communication with the anode inlet 122 and / or the anode outlet 121. Figure 4 A flow path 165 in fluid communication with the anode exhaust conduit 120 is shown. The fluid communication path 215 includes a lift valve 223 configured to coordinate the operation of the gas injection system 115 and the exhaust gas recirculation system 205 based on a pressure threshold. The lift valve 223 is arranged in series with a solenoid valve 220, which, when opened simultaneously with the lift valve 223, allows gas to flow through the exhaust gas recirculation system 205 via valve 210. In various embodiments, the pressure threshold is based on the pressure associated with the receiver tank 190 and / or the discharge pressure of the solenoid valve 225. In various embodiments, the discharge pressure within the solenoid valve 225 corresponds to the pressure of the actuating gas 230 within the exhaust gas recirculation system 205. In various embodiments, the solenoid valve 225 may be controlled by a controller.

[0051] In various embodiments, the lift valve 223 is configured to open when the discharge pressure of the solenoid valve 225 reaches a threshold pressure greater than the pressure associated with the injection tank 170. In some embodiments, the lift valve 223 is configured to open when the discharge pressure of the solenoid valve 225 is at least about 10 times greater than the pressure within the injection tank 170. In some embodiments, a discharge pressure of the solenoid valve 225 that is at least about 10 times greater than the pressure within the gas injection tank 170 may instruct the gas injection tank 170 to release most of the pressurized gas it contains. For example, a 10:1 ratio of the discharge pressure of the solenoid valve 225 to the pressure within the injection tank 170 may require the pressure in the injection tank 170 to drop below about 10 psi, after which the solenoid valve 225 may open to allow the actuating gas 230 at a corresponding pressure of about 100 psi to flow through it. Therefore, by controlling the operation of the exhaust gas recirculation system 205 based on the pressure within the gas injection system 115 via the booster valve 223, accidental operation of the exhaust gas recirculation system 205 is prevented, thereby correspondingly reducing the risk of excessive gas pressure (e.g., P1) in the anode inlet 122 and / or gas pressure (e.g., P3) in the anode outlet 121 and thus preventing anode overpressure.

[0052] Figure 5An anode exhaust gas recirculation system 205 within a fuel cell system 10 is shown, configured to operate in conjunction with an actively controlled gas injection system 115 to provide pressure rebalancing and prevent anode underpressure. The exhaust gas recirculation system 205 includes one or more high-speed exhaust valves 210 configured to control gas flow through path 213 and facilitate the injection of treated anode exhaust gas (e.g., treated stream) into anode exhaust gas conduit 120. The gas injection system 115 and the exhaust gas recirculation system 205 may be configured to operate cooperatively to restore pressure balance within the fuel cell system 10 in response to detected pressure changes associated with the fuel cell module 100, thereby preventing anode underpressure. The gas injection system 115 and the exhaust gas recirculation system 205 are fluidly connected via a fluid communication path 215. The fluid communication path 215 includes a lift valve 223 configured to coordinate the operation of the gas injection system 115 and the exhaust gas recirculation system 205 based on a pressure threshold. A lift valve 223 is arranged in series with a solenoid valve 225, which, when opened simultaneously with the lift valve 223, opens the exhaust gas recirculation valve 210 and the flow through the exhaust gas recirculation system 205 via valve 210. In various embodiments, the lift valve 223 may open if the pressure within the gas injection tank 170 is below a threshold amount, allowing gas from the actuating gas 230 to flow through it if the solenoid valve 225 has been actuated (e.g., via a controller). In various embodiments, the solenoid valve 225 may be actuated based on a pressure difference detected within the fuel cell module 100 (e.g., by the PDT 125). In various embodiments, the lift valve 223 is configured with safety safeguards to ensure that gas does not flow through the exhaust gas recirculation system 205 in the event of a solenoid valve 225 actuation failure (e.g., opening at the wrong time or opening for an extended period).

[0053] As shown in the figure, the second fluid connection path 235 can be fluidly connected between the exhaust gas recirculation system 205 and the gas injection system 115. In various embodiments, gas flow is achieved through the second fluid connection path 235 when the redundant lift valve 250 is in the open configuration. The second fluid connection path 235 is configured to achieve gas flow from the actuation gas 240 (via the flow orifice 245) to ensure that both the lift valve 223 and the redundant lift valve 250 receive the full actuation pressure (after a sufficient time, the connection path 235 is filled by the flow of the actuation gas 240 through the flow orifice 245), thereby ensuring that the lift valve 223 and / or 250 will open when the pressure in the gas injection tank 170 is approximately 1 / 10 of the actuation pressure, so that even if the lift valve 223 has automatically closed in case of failure, the recirculation valve 210 will definitely open to achieve pressure rebalancing within the fuel cell system 10 by supplying gas in the anode exhaust pipe 120.

[0054] In some embodiments, if the booster valve 223 has already opened automatically in the event of a failure, the solenoid valve 225 may allow gas to flow through it (e.g., based on a signal from a communicatively coupled controller), regardless of the pressure within the gas injection tank 170 (and / or the pressure associated with the fuel cell module 100), which could lead to anode overpressure. To confirm that neither of the two booster valves 223 and / or 250 has opened automatically in the event of a failure, the pressure in line 235 may be measured by a pressure transmitter 255, located within the fluid communication path 235, positioned between the solenoid valve 225 and the booster valves 223 and 250, and configured to confirm high pressure generated by the gas supplied by the actuating gas 240 within the redundant fluid communication path 235. The pressure maintained at the pressure transmitter 255 ensures that the booster valves 235 and 250 are fully closed. In various embodiments, the gas injection tank 170 may be similarly monitored via a pressure transmitter 260, configured to detect and monitor the pressure within the gas injection tank. In various embodiments, when the pressure within the gas-injected storage tank 170 (as detected by pressure transmitter 260) drops below a predetermined threshold, the solenoid valve 225 may be actuated (e.g., via a controller).

[0055] Figure 6 A schematic representation of an alternative configuration of an actively controlled gas injection system 115 in fluid communication with an exhaust gas recirculation system 205 within a fuel cell system 10, according to another exemplary embodiment, is shown. As shown, the gas injection system 115 is in fluid communication with the exhaust gas recirculation system 205 via a fluid communication path 215. As previously described, the gas injection system 115 and the exhaust gas recirculation system 205 can be configured to operate cooperatively to restore pressure balance within the fuel cell system 10 in response to changes in detected pressures (e.g., P1, P2, and / or P3) and / or pressure differences associated with the fuel cell module 100 (e.g., detected by PDT 125). In various embodiments, if the pressure within the gas injection reservoir 170 is below a threshold amount, a booster valve 223 can open, allowing gas from the actuating gas 230 to flow through it if the solenoid valve 225 has been actuated (e.g., via a controller). In various embodiments, the solenoid valve 225 can be actuated based on a pressure difference detected within the fuel cell module 100 (e.g., by PDT 125). In various embodiments, the lift valve 223 is configured with safety safeguards to ensure that gas does not flow through the exhaust recirculation system 205 in the event of a solenoid valve 225 actuation failure (e.g., opening at the wrong time or for an extended period of time) until the gas injection tank pressure 260 falls below a certain threshold.

[0056] As shown, a second fluid communication path 235 is positioned between the gas injection system 115 and the exhaust gas recirculation system 205. The second fluid communication path 235 includes a pressure transmitter 255 and flow orifices 265 and 270. In various embodiments, gas flow through the second fluid communication path 235 is achieved when the lift valve 223 or redundant lift valve 250 is in an open configuration. Flow orifices 265 and 270 are configured to achieve gas flow between the fluid communication path 215 and the second fluid communication path 235 such that the pressure measured by the pressure transmitter 255 will be approximately equal to the pressure of the gas injection tank (measured by the pressure transmitter 260) when the solenoid valve 225 is not actuated (i.e., closed), and approximately equal to the pressure of the actuator supply air 230 when the solenoid valve 225 is actuated (i.e., open), enabling the determination of malfunctions (i.e., misalignment) of the lift valve 223 or 250 and / or the solenoid valve 225 during operation of the fuel cell system 10. Because these components are redundant safety systems (e.g., second fluid path 235, flow orifices 265 and 270, redundant lift valve 250) to ensure that the recirculation system 205 does not flow at the same time as the gas injection system 115, a detected failure of any of the redundant valves (e.g., valves 223, 250) can notify and allow for possible replacement or repair prior to operation of the fuel cell system 10, which may expose the fuel cell module 100 to the risk of damage from excessive anode pressurization.

[0057] In some embodiments, if the lift valve 223 has already opened automatically in the event of a failure, the solenoid valve 225 (e.g., in response to an actuation signal received by a communicatively coupled controller) may allow gas to flow through it independently of the pressure within the gas injection tank 170 and / or the pressure differential associated with the fuel cell module 100, which could result in anode overpressure independent of the redundant lift valve 250, which also opens automatically in the event of a failure. To ensure that the lift valves 223 and 250 do not open automatically in the event of a failure, gas flow through flow orifices 265 and / or 270 can provide pressure upstream of the redundant lift valve 250 by enabling gas flow through them. Therefore, the second fluid communication path 235 may include a pressure transmitter 255, disposed between the solenoid valve 225 and the redundant lift valve 250, configured to confirm the pressure generated therein by the gas flow facilitated by flow orifices 265 and / or 270. The pressure maintained at the pressure transmitter 255 ensures that the lift valves 223 and 250 are fully closed. In various embodiments, the gas injection tank 170 can be monitored similarly via a pressure transmitter 260, which is configured to detect and monitor the pressure in the gas injection tank. In various embodiments, when the pressure in the gas injection tank 170 (as detected by the pressure transmitter 260) drops below a predetermined threshold, the solenoid valve 225 can be actuated (e.g., via a controller).

[0058] In various embodiments, the fuel cell system 10 may include additional overpressure and / or underpressure protection, which may be implemented in series or in parallel with the gas injection system 115 (e.g., a water seal). For example, the fuel cell system 10 may include a water seal system 405 (e.g., a gas injection system 115). Figure 3 As shown), it (e.g., via anode exhaust pipe 120 and / or connection path 410) is in fluid communication with the fuel cell module to prevent anode overpressure (e.g., over-pressurization).

[0059] In various embodiments, the gas injection system 115 may be implemented as a separate pressure rebalancing system within the fuel cell system 10, or the gas injection system 115 may operate in conjunction with one or more additional pressure mitigation systems (e.g., exhaust gas recirculation system 205, water seal system 405) to facilitate minimizing, preventing, or eliminating excessive pressure differentials within the fuel cell system 10. In any of the foregoing embodiments, the (actively or passively controlled) gas injection system 115 may be configured to operate when the pressure differential causes a short-duration anode pressure deficiency event. In various embodiments, the exhaust gas recirculation system 205 may be configured to operate when the pressure differential causes a longer-duration anode pressure deficiency event. In various embodiments, short-duration events may be classified as events lasting between approximately 0.5 seconds and 5 seconds. In various embodiments, longer-duration events may be classified as events lasting between approximately 2 seconds and 20 seconds.

[0060] In various embodiments, when the exhaust gas recirculation system is used in conjunction with a gas injection system, a passive system may be employed to ensure that the exhaust gas recirculation system is actuated only after the gas injection system. In various embodiments, the solenoid valve 225 within the exhaust gas recirculation system 205 may open only after the gas injection system 115 has released the gas pressure in the injected tank to below a threshold level. In various embodiments, the solenoid valve 225 within the exhaust gas recirculation system 205 may open only after the gas injection system 115 has been operating for a predetermined period of time (e.g., when valve 180 or regulator 200 is in an open configuration). In some embodiments, the predetermined period of time may correspond to an event of relatively long duration (e.g., at least 2 seconds).

[0061] In various embodiments, the gas injection system 115 may operate during or in direct response to one or more alarm conditions. In various embodiments, the one or more alarm conditions may be associated with insufficient anode pressure and / or pressure difference changes exceeding a predetermined threshold within the fuel cell system 10. In various embodiments, the gas injection system 115 may operate in conjunction with the exhaust gas recirculation system 205 during or in direct response to one or more alarm conditions, wherein the gas injection system 115 may operate during or in response to alarm conditions associated with lower severity (e.g., valve 180 or regulator 200 may open), and the recirculation system 205 may operate during or in response to alarm conditions of higher severity (e.g., solenoid valve 225 may open). In various embodiments, alarm conditions may correspond to pressure difference associated with the fuel cell module 100. For example, the gas injection system 115 can operate when the pressure difference reaches -1 inch water column (iwc) (e.g., valve 180 or regulator 200 can be opened), while the exhaust recirculation system 205 can operate when the pressure difference reaches -4 iwc (e.g., valve 210 can be opened).

[0062] Although the above text is Figure 1-6 Embodiments are described herein, but various modifications and inclusions of these embodiments are contemplated and considered within the scope of this disclosure.

[0063] It should also be understood that the construction and arrangement of the elements of the systems and methods shown in the representative embodiments are merely illustrative. Although only a few embodiments of this disclosure have been described in detail, those skilled in the art who examine this disclosure will readily understand that many modifications are possible (e.g., variations in the size, dimensions, structure, shape and proportions, parameter values, mounting arrangements, use of materials, color, orientation, etc.) without substantially departing from the novel teachings and advantages of the disclosed subject matter.

[0064] Therefore, all such modifications are intended to be included within the scope of this disclosure. Any device plus function clause is intended to cover the structures described herein as performing the stated functions, and not only structural equivalents, but also equivalent structures. Other substitutions, modifications, alterations, and omissions may be made in the design, operation, and arrangement of preferred and other illustrative embodiments without departing from the scope of this disclosure or the appended claims.

[0065] Furthermore, the functions and procedures described above can be performed by specialized equipment designed to perform specific functions and procedures. These functions can also be performed by general-purpose equipment that executes commands related to the functions and procedures, or each function and process can be performed by different equipment parts using a single equipment part acting as a controller or by using a separate control device.

[0066] The topics described herein sometimes refer to different components contained within or connected to different other components. It should be understood that such depicted architectures are merely exemplary, and many other architectures can actually be implemented to achieve the same functionality. Conceptually, any arrangement of components used to achieve the same functionality is actually “associated” to enable the desired functionality. Therefore, any two components combined herein to achieve a particular functionality can be considered “associated” with each other to enable the desired functionality, regardless of the architecture or intermediate components. Similarly, any two such associated components can also be considered “operably connected” or “operably linked” to each other to achieve the desired functionality, and any two components that can be so associated can also be considered “operably linked” to each other to achieve the desired functionality. Specific examples of components that can be operatedly linked include, but are not limited to, components that can be physically paired and / or physically interact and / or components that can interact wirelessly and / or components that can interact logically and / or components that can interact logically.

[0067] Regarding the use of any plural and / or singular terms in this document, those skilled in the art can convert from plural to singular and / or from singular to plural as appropriate to the context and / or application. For clarity, various singular / plural permutations may be explicitly described herein.

[0068] Those skilled in the art will understand that, in general, the terminology used herein, and especially in the appended claims (e.g., the body of the appended claims), is typically intended to be “open-ended” (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “including but not limited to,” etc.). Those skilled in the art will further understand that if a particular number of the introduced claim statements are desired, such an intent will be explicitly stated in the claims, and without such a statement, such an intent does not exist. For example, to aid understanding, the following appended claims may contain the introductory phrases “at least one” and “one or more” to introduce claim statements. However, the use of such phrases should not be construed as implying that a claim statement introduced by the indefinite article "a / an" would limit any particular claim containing such an introduced claim statement to a disclosure containing only one such statement, even when the same claim contains the introductory phrases "one or more" or "at least one" and indefinite articles (e.g., "a" should be interpreted as meaning "at least one" or "one or more"); the same applies to the use of definite articles used to introduce claim statements. Furthermore, even when a specific number of introduced claim statements is explicitly stated, those skilled in the art will recognize that such statements should generally be interpreted as meaning at least the number stated (e.g., stating "two statements" in the absence of other modifiers generally means at least two statements, or two or more statements). Furthermore, in cases where idioms such as "at least one of A, B, and C" are used, generally speaking, the intention of such construction is that those skilled in the art will understand the idioms (e.g., "a system having at least one of A, B, and C" will include, but is not limited to, a system having only A, only B, only C, both A and B, both A and C, both B and C, and / or both A, B, and C, etc.). In cases where idioms such as "at least one of A, B, or C" are used, generally speaking, the intention of such construction is that those skilled in the art will understand the idioms (e.g., "a system having at least one of A, B, or C" will include, but is not limited to, a system having only A, only B, only C, both A and B, both A and C, both B and C, and / or both A, B, and C, etc.). Those skilled in the art should further understand that any separate words and / or phrases that in fact represent two or more alternative terms, whether in the specification, claims or drawings, should be understood to cover the possibility of including one, any, or both of the terms.For example, the phrase “A or B” will be understood as including the possibility of “A” or “B” or “A and B”. Furthermore, unless otherwise stated, the use of words such as “approximately,” “about,” “roughly,” “generally,” etc., implies adding or subtracting ten percent.

[0069] Furthermore, although the accompanying drawings show a specific order of operation, the order of operations may differ from the depicted order. Additionally, two or more operations may be performed simultaneously or partially simultaneously. Such variations will depend on the hardware system chosen and the designer's selection. All such variations are within the scope of this disclosure.

Claims

1. A fuel cell system comprising: a fuel cell module comprising: an anode having an anode inlet configured to receive an anode feed gas and an anode outlet configured to output an anode exhaust into an anode exhaust conduit; and a cathode having a cathode inlet configured to receive a cathode feed gas and a cathode outlet; an anode exhaust treatment system fluidically coupled to the anode exhaust conduit; and a gas injection system disposed downstream of the anode outlet and upstream of the anode exhaust treatment system, the gas injection system comprising a first tank in fluid communication with a gas supply, the first tank configured to contain a gas received from the gas supply, wherein the first tank is structured to provide a flow of gas into the anode exhaust conduit, the first tank fluidically coupled to at least one control valve configured to maintain a pressure within the first tank at a predetermined set value; wherein the gas injection system is configured to inject the gas into the anode exhaust conduit upon detection of a current or projected anode under-pressurization condition; and an anode exhaust recirculation system fluidically coupled downstream of the anode exhaust treatment system, the anode exhaust recirculation system configured to recirculate anode exhaust from the anode exhaust treatment system to the anode exhaust conduit based on a current anode under-pressurization condition and a low pressure condition in the first tank.

2. The fuel cell system of claim 1, further comprising a second tank, the first tank directly coupled to the gas supply and the second tank configured to receive the gas from the first tank, and wherein a flow of the gas from the first tank to the second tank is metered by a first valve.

3. The fuel cell system of claim 2, wherein a pressure within the second tank is maintained at a predetermined set value based on operating conditions of the fuel cell system.

4. The fuel cell system of claim 1, wherein the gas injection system is configured to inject the gas in response to a determination that a pressure differential between the anode outlet and the cathode inlet exceeds a predetermined threshold.

5. The fuel cell system of claim 1, wherein the gas injection system is configured to inject gas based on an operating parameter associated with the fuel cell module, the operating parameter indicative of a projected anode under-pressurization condition.

6. The fuel cell system of claim 1, wherein the anode exhaust recirculation system is configured to operate in coordination with the gas injection system, wherein the anode exhaust recirculation system is configured to operate in series with the gas injection system.

7. The fuel cell system of claim 1, further comprising a first poppet valve disposed within a first path fluidically coupled between the anode exhaust recirculation system and the gas injection system.

8. The fuel cell system of claim 7, wherein the first poppet valve is fluidly coupled in series with at least one other valve configured to allow flow through the anode exhaust recirculation system.

9. The fuel cell system of claim 8, wherein the at least one other valve is a solenoid valve.

10. The fuel cell system of claim 7, further comprising a second poppet valve disposed within a second fluid path fluidly coupled between the anode exhaust recirculation system and the gas injection system, wherein at least one of the first poppet valve or the second poppet valve is fluidly coupled in series with a pressure transmitter, and wherein an output from the pressure transmitter indicates that at least one of the first poppet valve or the second poppet valve automatically opens upon failure.

11. The fuel cell system of claim 1, further comprising a water seal system in fluid communication with the fuel cell module and configured to prevent pressurization over-conditions of the anode.

12. A method of rebalancing pressure within a fuel cell system, the method comprising: receiving inert gas from a supply at a receiver tank; determining, by a pressure differential transmitter, a pressure differential between an anode outlet and a cathode inlet, the anode outlet and the cathode inlet included within a fuel cell module; and injecting, by a gas injection system in fluid communication with the anode outlet of the fuel cell system, the inert gas from the receiver tank into an anode exhaust conduit via an injection path; wherein the anode exhaust conduit is fluidly coupled to the anode outlet and an anode exhaust treatment system, and wherein the injection path is disposed downstream of the anode outlet and upstream of the anode exhaust treatment system; and wherein injecting the inert gas into the anode exhaust conduit causes a pressure rebalancing between the anode outlet and the cathode inlet; and recirculating, by an anode exhaust recirculation system, anode exhaust from the anode exhaust treatment system to the anode exhaust conduit based on a pressurization under- condition of a current anode and a low pressure condition in the receiver tank.

13. The method of claim 12, wherein injecting the inert gas into the anode exhaust conduit is performed in anticipation of a possible pressure change within the fuel cell module.

14. The method of claim 12, wherein limiting a peak flow of the inert gas from the supply to the receiver tank to limit a peak demand on the supply.

15. The method of claim 12, wherein recirculating anode exhaust is delayed to be later than injecting the inert gas from the injection path.

16. A method of rebalancing pressure within a fuel cell system, the method comprising: receiving inert gas from a supply at a receiver tank; sensing, by a first pressure sensor, a first pressure within an anode outlet conduit fluidly coupled to an anode outlet of a fuel cell module, wherein the first pressure sensor is in communication with a pressure differential regulator; sensing a second pressure at a cathode inlet contained within the fuel cell module with a second pressure sensor, wherein the second pressure sensor is in communication with the pressure differential regulator; and allowing, by the pressure differential regulator, the inert gas to flow from the receiver tank through the pressure differential regulator into an injection path based on the first pressure and the second pressure, wherein the gas flows into the injection path and into an anode exhaust conduit; wherein the gas entering the anode exhaust conduit causes a pressure rebalancing between the anode outlet and the cathode inlet; and recirculating, by an anode exhaust recirculation system, anode exhaust from the anode exhaust treatment system to the anode exhaust conduit based on a current anode pressurization deficiency and a low pressure condition in the receiver tank.

17. The method of claim 16, further comprising: treating, by an anode exhaust treatment system in fluid communication with the anode outlet conduit, anode exhaust from the anode outlet conduit to produce treated anode exhaust; recirculating, by an anode exhaust recirculation system in fluid communication with the anode outlet conduit, treated anode exhaust from the anode exhaust treatment system to the anode exhaust conduit.

18. The method of claim 17, wherein treating the anode exhaust comprises performing a gas shift reaction.

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