Mitigating Water Accumulation in Fuel Cells

Immersion cooling system with bellows to reduce volume and footprint while preventing liquid accumulation. The system has a tank with a headspace above the liquid. A bellows is gaseously coupled with the headspace below the bottom of the space. This bellows compresses/expands as the headspace pressure changes. It reduces the volume required for the headspace gas and condenses vapor to prevent liquid accumulation. A condenser removes heat from the bellows gas. A pump drains excess liquid. Heat sources heat the bellows. Insulation prevents condensation. Multiple bellows can be used inside/outside the tank.

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Cooling system for fuel cells in vehicles like aircraft that uses a two-phase coolant to reduce weight and size while providing more uniform cooling compared to air cooling. Water droplets are sprayed into the coolant airstream upstream of the fuel cell to absorb heat. The coolant then condenses water vapor downstream. This allows a smaller coolant flow rate since water's latent heat of vaporization absorbs more heat than air. The water can be recycled. The coolant circuit can have a PCM for evaporative cooling at lower pressures.

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Fire protection system and method for preventing condensation in fire suppression systems to avoid issues like mold, corrosion, or short circuits. The system uses a fuel cell to generate oxygen-reduced cathode exhaust gas. This gas is dried before entering the protected space. A control system checks the dew point and allows entry only if it's below a set threshold. This ensures the gas is dry enough for the protected space application.

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Fuel cell bipolar plate design with optimized flow channels to improve performance and reduce flooding. The plate has hybrid channels that combine parallel channels at the inlet and outlet with interwoven channels in the reaction region. The interwoven channels have primary and secondary channels that merge and have varying sizes. This flow pattern is optimized using topology optimization to balance flow resistance, uniformity, and water removal. The optimized channels facilitate clearance of water in the GDL under the ribs and force oxygen into the GDL.

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Fuel production system that reduces water waste and prevents water vapor shortage in fuel cell electrolyzers. The system has gas-liquid separators before and after the electrolyzer. Water vapor from separated water and external sources is supplied to the electrolyzer along with the feed gas. This ensures sufficient water vapor for electrolysis even when feed water ratio varies. It also recycles water vapor instead of wasting it. The separator after the synthesizer further recycles water vapor.

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Method for operating a fuel cell system to precisely determine the optimal time to empty a water separator container without using a level sensor. The method involves recirculating anode gas, separating liquid water in a water separator, measuring hydrogen content downstream after purging, and detecting a delayed increase to indicate the container is full.

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Porous metal gas diffusion layer (GDL) for fuel cells with improved water management. The GDL has flow channels defined by walls with surfaces having the same porosity as the rest of the GDL. This prevents compression and porosity reduction during channel formation. The channels allow capillary water flow and film-wise condensation on superhydrophilic surfaces. This promotes uniform reactant distribution and water removal in fuel cells.

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Unitized fuel cell stack design with internal water drainage to prevent flooding of the cell reaction area. The design involves a 3D-printed frame around the cell components that has integrated drainage channels. The frame is made of multiple sheets bonded together to form a discharge flow field inside the frame. This allows water generated during cell operation to flow out and prevent it from pooling on the cell components. The frame also has through-holes to connect the drainage channels to the cell manifold ports for water removal.

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A fuel cell system anode gas recirculation device with integrated water separation and cooling for the blower motor. The device has a blower with a rotor wheel, motor, and delivery channel to recirculate anode gas. The blower motor cooling channel surrounds the motor and connects to a condensate drain channel below. A valve in the drain channel allows controlled discharge of separated water. This integrates water separation, motor cooling, and condensate management in the blower housing.

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Fuel cell system that suppresses white smoke in the exhaust to reduce visibility issues when the system is installed in public areas. The system mixes exhaust gas with air in a mixing section to dilute it. This diluted exhaust is then discharged. A water receiver collects condensed water formed by the exhaust condensation. A drainage section empties the receiver to prevent flooding.

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Fuel cell device with improved water management to prevent mixing of condensed water and rainwater. The device has separate chambers for collecting condensed water from exhaust and rainwater entering through the exhaust port. An intermediate chamber between the chambers prevents mixing. This allows efficient condensed water recovery without contamination.

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Fuel cell system with multiple water drainage locations to allow reliable water removal from the fuel cell stack regardless of vehicle orientation. The system has two water collection areas, one for normal operation and one for uphill operation. It has valves to close and open the drains based on learned liquid levels and orientation. This allows water to be removed from both areas during operation. It also allows purging gas through the secondary drain when the primary one is blocked.

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Fuel cell device with integrated evaporative cooling to simplify cooling and eliminate external water needs. The fuel cell exhaust air contains water from the reaction. This water is collected and reused to cool the fuel cell by a dedicated evaporative cooler. A water separator removes excess water from the exhaust, which is then fed to the cooler. This closed loop prevents freezing in cold temperatures by recycling the water from the exhaust instead of needing external water. The evaporative cooler avoids the need for a separate external water source for cooling.

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Fuel cell system with improved condensate management to prevent flooding and improve reliability. The system has a drain valve to remove condensate from the fuel cell stack, an inlet port in the humidifier to suck condensate from the drain valve, and a negative pressure application unit in the humidifier to create suction at the inlet port. This allows condensate to be sucked from the drain valve and supplied to the humidifier without needing a separate pump. The negative pressure is generated by surrounding the inlet port with a housing and guide port to direct airflow. The negative pressure area is defined between the outlet port and negative pressure application hole.

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A fuel cell system with an integrated humidification and water replenishment method that addresses the issue of low humidity in fuel cell air supply. The system uses exhaust gas from the fuel cell stack to humidify the intake air. It collects exhaust gas moisture in a tank, feeds it to an atomizer to humidify the intake air, and separates the moisture from the exhaust gas. This allows sufficient humidification without external humidifiers. The system also has a water replenishment method that optimizes liquid levels in the tank based on stack operation. It replenishes water when levels are low and stops when full. This prevents dehydration during stack shutdowns.

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Stack structure for fuel cells that improves stack performance by preventing low cell voltage and flooding issues. The stack has a stack body with true cells connected by channels, and false cells at the ends. The false cells have channels connected to the main channels. A water guide plate collects condensation from the air inlet channels and directs it to the false cell channels. This prevents water flooding the true cells and reduces stack temperature gradients. The false cells also improve stack temperature uniformity by cooling the stack body through channels connected to the coolant inlet/outlet.

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Fuel cell system with improved humidification to extend operating limits without increasing complexity. It recycles water from the anode outlet to humidify the oxidant line. A water detection unit measures the anode water flow to optimize cathode humidification. This prevents dehydration of the membrane and cathode entry area, especially at high temperatures or altitudes.

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Fuel cell system with active humidification to precisely control humidity for optimal fuel cell performance. The system has a dedicated module to collect water discharged from the cathode and a humidification module to use that water to humidify intake air. A control module adjusts the water injection based on target humidity, environment, and stack data. This allows real-time optimization of humidity levels inside the fuel cell stack. An impedance spectrometer measures stack humidity to further refine the control.

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Improving water management in the cathode catalytic layer of proton exchange membrane fuel cells (PEMFCs) to enhance performance and durability. The technique involves creating a three-layer structure with a hydrophilic-hydrophobic gradient in the cathode catalytic layer. The layers are prepared using catalyst slurries with different sulfonated perfluorosulfonic acid resins having varying water contents. A hydrophilic layer close to the membrane is made with a low EW (equivalent weight) resin, a hydrophobic layer near the gas diffusion layer is made with a high EW resin, and an intermediate layer uses a mixture of resins with varying EW. This gradient helps balance water retention and distribution in the cathode catalytic layer for better fuel cell performance and longevity.

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Fuel cell system with improved humidification for high load conditions that reduces cost and size compared to conventional humidifiers. The system has a conventional humidifier with water-permeable membranes to transfer moisture from exhaust to supply air. But it also has an additional moisture return path with a water separator, collector, and injector. Exhaust air is separated to remove water droplets, then stored temporarily. This separated moisture can then be injected into the supply air for humidification. This allows the conventional humidifier to be sized for nominal load rather than peak load, reducing cost and size. The additional moisture return provides supplemental humidification for high load conditions.

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