Liquid Hydrogen for Fuel Cell Operations

A fuel cell system with temperature control for the hydrogen tank to maintain consistent hydrogen density and accuracy of state of charge calculations. The system has a heater and cooler to adjust the tank temperature based on measurements. It uses a valve to selectively circulate coolant between the tank and an electrical component. By controlling the heater/cooler and valve based on tank temperature, it can maintain the hydrogen tank at a stable temperature for accurate fuel calculations, especially in applications like aerial vehicles where temperature fluctuations can affect measurements.

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Thermal management system for hydrogen storage and supply with improved response time and efficiency. The system uses a comprehensive energy management and control system to optimize the response time of a hydrogen storage and transportation system. It involves coupling a hydrogen storage device with a hydrogen supply subsystem, a water storage subsystem, a hot water subsystem, and a cooling water heat exchanger. The system recovers waste heat from a fuel cell to heat the hydrogen storage device for faster hydrogen release. It also uses flow regulation to improve emergency response time. The system enables rapid, unattended hydrogen storage and supply with higher energy efficiency.

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Energy transfer and supply system for hydrogen-powered aircraft that efficiently utilizes liquid hydrogen from low-temperature storage to fuel cells and engines. The system allows liquid hydrogen from a tank to be vaporized, pressurized, and routed to either fuel cells or engines based on demand. This allows flexible utilization of the liquid hydrogen for high-efficiency fuel cell operation or engine heating/combustion. It also involves heat exchangers to absorb waste heat from onboard systems and transfer it to the liquid hydrogen. A controller manages the routing and valves based on demand.

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Hydrogen fuel cell system with dynamic hydrogen consumption adjustment to avoid waste and reduce operating costs. The system has a hydrogen supply subsystem, a hydrogen buffer subsystem, a fuel cell subsystem, and a control subsystem. The buffer subsystem contains a booster pump, tank, and valve. The control subsystem adjusts pump pressure, valve opening, and fuel cell hydrogen production rate based on fuel cell power and tank pressure changes. This allows dynamic hydrogen consumption matching to prevent waste compared to fixed supply.

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Fuel cell system for drones that uses liquid hydrogen as fuel instead of gaseous hydrogen. The system has a liquid hydrogen storage device that transports the liquid hydrogen to a heat exchanger. The heat exchanger converts the liquid hydrogen to gaseous hydrogen by exchanging heat with coolant. This eliminates the need for additional heating devices and reduces weight compared to gaseous hydrogen systems. The gaseous hydrogen is then used to power the fuel cell stack. The coolant circuit is also used for cooling other components.

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A hydrogen production and fuel cell system that recycles the electricity generated by fuel cells to further produce hydrogen. The system has a hydrogen production device, a hydrogen storage device, a proton exchange membrane fuel cell (PEMFC), an electric energy storage component, and a reversible solid oxide fuel cell (RSOFC). The PEMFC uses hydrogen from storage to generate electricity, which is stored. The RSOFC uses hydrogen from storage to generate electricity, or uses electricity from storage to generate hydrogen. This allows full utilization of fuel cell electricity for hydrogen production or consumption.

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A high density liquid hydrogen storage system for fuel cell applications that improves energy density and reduces weight compared to high pressure hydrogen storage. The system uses subcritical (below boiling point) liquid hydrogen stored in a tank. A vaporizer converts the liquid hydrogen to gas using waste heat from the fuel cell. A heat exchanger, pressure regulator, and flow controller adjust the gas temperature, pressure, and flow to match fuel cell requirements. Feedback controls using sensors in the tank and vaporizer ensure reliable operation.

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A hydrogen fuel cell generator set that allows continuous operation without interruption for refueling. The set has two hydrogen storage tanks that can be switched to provide hydrogen to the fuel cell when one tank is empty. This allows uninterrupted operation as the fuel cell can draw from the non-empty tank while the empty tank is being refilled. The switch between tanks prevents fuel depletion and maintains hydrogen supply pressure. The set also has methods to dissipate the high internal heat generated by the fuel cell to prevent damage and reduce degradation.

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A quick-start liquid hydrogen storage and supply system that reduces start-up time of liquid hydrogen fuel systems by utilizing magnetocaloric efficiency to reliquefy evaporated hydrogen and soak the liquid hydrogen pump. This prevents significant hydrogen losses during pump start-up and allows the pump to operate in the liquid hydrogen temperature range. The system uses components like a liquid hydrogen bath, vaporizer, heat exchangers, fuel cells, and magnets. The vaporized hydrogen improves insulation of the storage tank and the magnets provide magnetocaloric cooling.

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Low-temperature hydrogen storage device and fuel cell integrated power supply system that enables fast response and low-temperature self-starting of low-temperature hydrogen storage devices and fuel cells. The system uses a hydrogen catalytic flameless combustion microreactor to heat the hydrogen storage tank and catalyze remaining hydrogen to provide heat and hydrogen for fuel cell startup. An automatic temperature control system adjusts the microreactor power based on tank temperature and pressure to heat the tank to hydrogen release temperature. This allows utilizing tail hydrogen from the fuel cell or residual hydrogen in the tank to start the fuel cell without external heating.

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Cold start method for hydrogen fuel cells using liquid hydrogen storage. The system allows rapid cold starts by utilizing throttling and heating when the liquid hydrogen temperature is below the conversion temperature. This avoids the need for external heating devices. The method involves vaporizing liquid hydrogen using air and then cooling it with low-pressure hydrogen. This provides preheated hydrogen for the fuel cell. The system also has a hydrogen burner and heat exchangers to utilize the high-grade cooling and heating of liquid hydrogen for thermal management.

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An integrated power system for vehicles that allows onboard power generation using hydrogen and oxygen when the main engine is off. The system uses a reversible fuel cell stack that can operate as a hydrogen generator or electricity generator. In one mode, it receives water and electricity from the vehicle engine, electrolyzes water to generate hydrogen, stores the hydrogen, and uses hydrogen combustion to generate electricity. In the other mode, it uses stored hydrogen to generate electricity. This allows self-sufficient onboard power when the main engine is off.

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A hydrogen fuel cell hydrogen supply system for vehicles that improves stability and controllability of the hydrogen supply to the fuel cell stack. The system uses a small-volume relay hydrogen storage tank with a refrigeration device to convert high-pressure hydrogen from the main tank to liquid at lower pressure. This isolated low-pressure hydrogen loop provides a stable and controllable supply to the fuel cell stack, preventing pressure fluctuations and ensuring long-term stable operation. Valves, sensors, and pumps manage the hydrogen flow between tanks and the fuel cell.

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A hydrogen fueled high altitude aircraft using a thermodynamic fuel cell system that maximizes efficiency and minimizes environmental impacts. The system compresses inlet air using multiple compressors and cools it using liquid hydrogen to maintain low temperature for the fuel cell. The hydrogen is also compressed and expanded before the fuel cell. The exhaust is cooled to condense water that is collected and expelled as ice. The high efficiency hydrogen conversion enables long range flight with lower fuel volumes. The VTOL aircraft can fly at high altitude with reduced environmental impact.

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Hydrogen cycle thermal management system for fuel cell engines that improves performance and stability in cold environments by maintaining hydrogen temperature before entering the fuel cell stack. The system uses a sequence of components like valves, heat exchangers, tanks, and a pump to circulate and heat hydrogen. It also recycles water from the fuel cell stack to further heat the hydrogen. This prevents hydrogen from cooling excessively during storage and transit, improving stack reaction efficiency and engine performance in cold conditions.

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Fuel cell system with a hydrogen supply that includes a medium-pressure accumulator between the pressure regulator and the metering valve. This prevents pressure fluctuations when the hydrogen tanks empty during operation. The accumulator minimizes gas-related and thermodynamically-related pressure changes at the fuel cell inlet. It is thermally connected to the fuel cell stack to improve temperature management. The accumulator is directly connected to the line between the regulator and valve with no additional valve.

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Power generation system with improved efficiency using a combination of internal energy extraction from high-pressure hydrogen and conventional fuel cell power generation. The system has a high-pressure hydrogen storage tank, expander-generator to extract internal energy from high-pressure hydrogen, fuel cell stack, and heat exchanger. The expander-generator converts high-pressure hydrogen into low-pressure hydrogen while extracting mechanical energy. This low-pressure hydrogen feeds the fuel cell stack along with air. The heat exchanger uses waste heat or solar energy to preheat the high-pressure hydrogen before expansion. This enables extracting more internal energy from the high-pressure hydrogen. The overall system converts both chemical and internal energy of hydrogen to electrical output.

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An integrated hydrogen storage alloy hydrogen fuel cell system that uses the heat released during hydrogen absorption by the storage alloy to improve efficiency and reduce energy consumption compared to traditional fuel cell systems. The system has a fuel cell stack, hydrogen storage tank, hydrogen supply device, air supply device, heat exchange cycle device, and control device. The hydrogen storage tank contains a hydrogen-absorbing alloy. During dehydrogenation, an electric heater at the tank outlet heats the alloy to increase hydrogen desorption. The heat exchange cycle transfers heat between the tank and stack. During hydrogenation, the tank releases heat to the stack. This avoids the need for bulky radiators and allows using the tank as a heat sink.

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Fuel cell system operation method to prevent fuel cell degradation when starting up from a cold standby. The method involves recovering boil-off hydrogen gas from the liquid hydrogen tank and supplying it to the fuel cell stack if the hydrogen concentration at the anode falls below a threshold. This prevents air infiltration into the anode during standby. The boil-off gas is compressed before injection to match stack operating pressure. The system uses valves and flow paths to control hydrogen flows between the tank, stack, compression and heating units.

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Fuel system for vehicles like aircraft with engines that can use liquid or gaseous hydrogen fuel. The system has separate tanks for liquid hydrogen and gaseous hydrogen, and parallel delivery lines. The liquid line has a pump and heat exchanger, while the gaseous line extends alongside. A regulator with surge tank connects both lines. During low power, liquid hydrogen pumps and heats. During high power, gaseous hydrogen from the tank supplies. This allows efficient pump sizing vs high demand. The surge tank buffers flow rate changes.

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