Abstract: Technologies are described herein for conditioning fluids stored in an underwater cryogenic storage vessel designed for use in a fuel system of an underwater vehicle. According to one aspect of the disclosure, a fuel system includes a fuel cell and a storage vessel, which stores a first fluid that is supplied to the fuel cell and a second fluid that is produced by the fuel cell. The fuel system also includes a thermal conditioning module that receives the first fluid from the storage vessel and receives the second fluid from the fuel cell. The first fluid stored in the storage vessel is conditioned by absorbing heat from the second fluid, such that the fuel cell receives the conditioned first fluid. The second fluid received from the fuel cell is in gaseous state and is converted to a liquid. The liquid second fluid is stored in the storage vessel.

Abstract: Technologies are described herein for conditioning fluids stored in an underwater cryogenic storage vessel designed for use in a fuel system of an underwater vehicle. According to one aspect of the disclosure, a fuel system includes a fuel cell and a storage vessel, which stores a first fluid that is supplied to the fuel cell and a second fluid that is produced by the fuel cell. The fuel system also includes a thermal conditioning module that receives the first fluid from the storage vessel and receives the second fluid from the fuel cell. The first fluid stored in the storage vessel is conditioned by absorbing heat from the second fluid, such that the fuel cell receives the conditioned first fluid. The second fluid received from the fuel cell is in gaseous state and is converted to a liquid. The liquid second fluid is stored in the storage vessel.

Abstract: A fluid management system for a cryogenic tank may include a liquid acquisition device and a spray injection system. The cryogenic tank may include a tank wall and may contain bulk tank fluid. The liquid acquisition device may acquire and contain cryogenic fluid in substantially liquid phase. The liquid acquisition device may be mounted in spaced relation to the tank wall. The spray injection system may receive the liquid from the liquid acquisition device and may spray the liquid into the bulk tank fluid.

Abstract: Technologies are described herein for storing fluid in an underwater cryogenic storage vessel designed for use in a fuel system of an underwater vehicle. According to one aspect of the disclosure, a storage vessel includes at least two concentrically arranged storage tanks, which includes a first storage tank and a second storage tank. The first storage tank surrounds the second storage tank, such that the first storage tank is configured to protect the second storage tank from external environmental conditions. The storage vessel also includes a storage compartment positioned adjacent to the two storage tanks. In one embodiment, the storage vessel may be an underwater cryogenic storage vessel that stores liquid oxygen used as a reactant in a fuel cell and liquid carbon dioxide, which is an effluent of the fuel cell.

Abstract: Technologies are described herein for conditioning fluids stored in an underwater cryogenic storage vessel designed for use in a fuel system of an underwater vehicle. According to one aspect of the disclosure, a fuel system includes a fuel cell and a storage vessel, which stores a first fluid that is supplied to the fuel cell and a second fluid that is produced by the fuel cell. The fuel system also includes a thermal conditioning module that receives the first fluid from the storage vessel and receives the second fluid from the fuel cell. The first fluid stored in the storage vessel is conditioned by absorbing heat from the second fluid, such that the fuel cell receives the conditioned first fluid. The second fluid received from the fuel cell is in gaseous state and is converted to a liquid. The liquid second fluid is stored in the storage vessel.

Abstract: Technologies are described herein for storing fluid in an underwater cryogenic storage vessel designed for use in a fuel system of an underwater vehicle. According to one aspect of the disclosure, a storage vessel includes at least two concentrically arranged storage tanks, which includes a first storage tank and a second storage tank. The first storage tank surrounds the second storage tank, such that the first storage tank is configured to protect the second storage tank from external environmental conditions. The storage vessel also includes a storage compartment positioned adjacent to the two storage tanks. In one embodiment, the storage vessel may be an underwater cryogenic storage vessel that stores liquid oxygen used as a reactant in a fuel cell and liquid carbon dioxide, which is an effluent of the fuel cell.

Abstract: A cryogenic propellant storage tank system and method are disclosed that thermally couple LO2 and LCH4 tanks together by using either a single tank compartmentalized by a common tank wall or two separate tanks that are coupled together with one or more thermal couplers having high thermal conductivity. Cryogenic cooling equipment may be located only in the LO2 tank while the LCH4 is cooled by the LO2 tank interface. Embodiments of the invention may employ both LO2 and LCH4 liquid acquisition devices (LADs) for low-gravity use. In further embodiments, only the LO2 LADs may be integrated with thermal cooling equipment.

Abstract: A rolled belt heat exchanger utilizes the increased heat transfer due to a large, extended surface belt. Heat is transferred from a heated roller to the belt, and then allowed to radiate to space as the belt follows a generally flattened oval path away from the heated roller.

Abstract: A three-way heat pipe configured in a generally Y-shape having a condenser-evaporator or heat-sink end, an evaporator arm and a condenser arm. In addition to conventional internal pumping the heat pipe is mechanically pumped externally from the heat-sink end to the evaporator arm. Heat transfer can take place between any two of the three elements by thermostatically controlling the external pump. Heat or cold may be stored in a suitable medium surrounding the condenser-evaporator end of the pipe for later transfer through the condenser or evaporator ends used as heat exchangers without a secondary circulation system. Heat transfer may also take place directly between the evaporator and condenser arms without storage. In the preferred embodiment of the heat storage configuration, a valve is placed in the condenser arm to prevent unwanted heat transfer.