Boeing North American, Inc.

Rockwell International Corporation

The Boeing Company

Tibor I Lak

David L Gerhardt

John E Davis

James F Weber

Timothy L Gaynor, Iii

Michael V Merlin

Gene Rogers

Martin Edward Lozano

Jay Kenji Yoshinaga

Andrew Tibor Lak

John H LeBlanc

Donna M Brakeville

Paul J Su

Steve P Petrilla

A liquid-vapor separation system for use in a zero gravity environment for transferring and storing fluids, and particularly fluids that are primarily liquid, such as propellants, reactants and coolants, among others, has a low supply tank pressure and low pressurant gas requirement, which results in maximized capacity, reduced system weight and reduced cost. The temperature of a container provided as part of the present invention is decreased below the freezing point of residual liquid within the container. Non-compressible gas is thereafter vented and the liquid raised to liquid temperature. Gaseous contaminants are thereby vented and subsequent filling of the container is thereby maximized.

Zero gravity liquid-vapor separation system

An improved and simplified system for densifying a cryogenic liquid for space vehicles is provided, which includes a heat exchanger having heat exchange tubes therein for receiving a flow of liquid from a storage tank, for example a liquid propellant in a vehicle storage tank. The heat exchanger is filled around the exchange tubes with a two-component bath, the volume of a primary component substantially exceeding the volume of a secondary component. The secondary component has a boiling temperature that is lower than the boiling temperature of the primary component, and both are lower than the boiling temperature of the cryogenic liquid. In one example, the liquid to be densified is oxygen, the primary component is liquid nitrogen, and a secondary component is liquid hydrogen. The secondary component is preferably injected into the heat exchanger in separate flows to prevent localized freezing of the first component. A manifold having a plurality of injectors may be used for introducing the second component to the heat exchanger. A control system receives inputs from one or more sensors within the heat exchanger and operates valves that control the flow of the first and second components of the heat exchange bath.

Methods and apparatus for liquid densification

A system for providing cryogenic sub-critical liquid oxygen and liquid hydrogen to storage tanks and payloads contained inside the payload bay of a space vehicle is described. The system provides for transferring cryogenic fluid from a supercritical storage tank to a subcritical storage tank or payload in a zero-g environment, wherein the H and O ignition hazard has been eliminated due to the low vacuum pressure operating environment. The system includes an external heat exchanger, for example, a parallel flow concentric tube design, and a temperature control system for re-condensing the two-phase transfer fluid expelled from the supercritical storage system into a single phase, sub-cooled cryogenic fluid which is then introduced into and stored within the subcritical storage tank.

Cryogenic fluid supply from supercritical storage system

A cryogenic liquid heat exchanger system has a subatmospheric pressure reservoir, a tube, and an initial fluid ejector. The sub-atmospheric pressure reservoir has a vacuum exhaust. The tube extends through the reservoir. The initial fluid ejector has a suction chamber inlet that is functionally connected to the reservoir vacuum exhaust. The system may have a plurality of fluid ejectors connected to one or more exhausts either in series or parallel. The initial fluid ejector may receive one or more pressurized fluid streams, and the streams may be steam. A process for generating sub-atmospheric pressures in a cryogenic fluid heat exchanger reservoir includes the step of discharging an initial fluid stream into an initial fluid ejector having a suction chamber functionally connected to an exhaust of the reservoir. A process for generating sub-atmospheric pressures in a cryogenic fluid heat exchanger reservoir includes the step of using a fluid ejector to reduce the pressure in the reservoir. In either process, cooling cryogenic fluid is directed through the reservoir. The cooling cryogenic fluid may be liquid nitrogen or liquid hydrogen. In either process, an incoming cryogenic fluid stream is directed through a tube that extends through the reservoir. The incoming cryogenic fluid may be liquid oxygen or liquid hydrogen, or any other suitable cryogenic fluid.

Cryogenic liquid heat exchanger system with fluid ejector

A system and method for cooling a first cryogenic liquid in a vessel comprises the steps of directing a second cryogenic into the first cryogenic fluid and releasing gas from the vessel. The first cryogenic fluid has a boiling point that is higher than the boiling point of the second cryogenic fluid. Directing the second cryogenic fluid into the first cryogenic fluid results in the second fluid cooling the first fluid and the second fluid vaporizing. The vaporized fluid is released as a gas from the vessel. The vessel may be a propellant tank for a space vehicle. The first and second cryogenic fluids are delivered from supplies located outside of the vehicle. The first cryogenic liquid may be oxygen and the second cryogenic liquid may be nitrogen, neon, or helium. In another aspect of the invention, the first cryogenic liquid may be hydrogen and the second cryogenic liquid may be helium.

Cryogenic densification through introduction of a second cryogenic fluid

Slush is made from a liquid using slush making systems or according to slush making processes. A jacketed vessel of the processes and the systems has an interior wall that defines an interior space. The interior space comprises a top and a bottom. The interior space has an average overall cross-sectional area taken through a vertical axis extending generally between the top and the bottom. The interior space also has a collection portion having an average collection portion cross-sectional area taken through the vertical axis that is less than the average overall cross-sectional area. The liquid is placed into the interior space and the interior walls are cooled. Slush forms on the interior walls and migrates to the collection portion. The collection portion is located at the interior space bottom when the slush density is higher than the liquid density and the collection portion is located at the interior space top when slush density is less than the liquid density. To facilitate the migration of the slush to the collection portion, at least a conical portion of the interior space has the general shape of a cone and the collection portion is located in the proximity of an apex of the conical portion, thereby helping to funnel the slush to the collection portion. The cryogenic liquid to be made into slush may be oxygen, nitrogen, hydrogen, helium, or water. The slush may be used to densify cryogenic liquids, such as cryogenic liquid propellants.

Slush producing process and device

A cryogenic propellant tank system and process for densifying cryogenic liquid propellant comprises a tank with a combined manifold, a combined manifold line, a pressurizing gas line, and a vent line. The combined manifold is located in the tank. The combined manifold line functionally connects the combined manifold to a chilling system. The pressurizing gas line and the vent line are also functionally connected to the combined manifold line. The tank may be disposed in a vehicle. The manifold is disposed proximate the top of the tank. The chilling system may be a heat exchanger/filling system. The process for filling the tank comprises the steps of charging the tank with cryogenic liquid propellant, venting gases in the tank, densifying the cryogenic liquid propellant, and pressurizing the tank. The tank is charged with the cryogenic liquid propellant such that the orifices in the combined manifold are submerged. The gases in the tank are vented through the combined manifold and out of the tank. The venting step is arrested prior to the submerging of the combined manifold orifices. The liquid in the tank is densified by directing a recirculation stream of the cryogenic liquid propellant from the tank through the combined manifold, out of the tank, cooling and directing the recirculation stream back into the tank. The tank is pressurized by directing a pressurizing gas stream into the combined manifold and into the tank.

Combined diffuser and recirculation manifold in a propellant tank

Leakage of propellants such as oxygen and hydrogen in an enclosed environment in the atmosphere can lead to fires or explosions. For storage tanks on reusable launch vehicles such as the space shuttle where propellant is to be stored in the cargo bay of the vehicle, the storage tank should be filled while the vehicle is at a safe altitude to avoid the dangers associated with propellant leakage. The invention a process for filling propellant tanks at safe altitudes where if there is propellant leakage ignition will not occur. The process involves launching the vehicle with an inert gas in the storage tanks, dumping the inert gas and filling the tanks in the cargo bay from the main propellant tanks during the launch once the vehicle is at a safe altitude. The propellant can be dumped overboard and the storage tanks filled with an inert gas in case of a mission abort if the vehicle needs to make an emergency landing.

Cyrogenic upper stage for reusable launch vehicle

Super cooling the cryogenic liquid propellant in a vehicle propellant tank densities the propellant allowing the vehicle propellant tank to carry more fuel in the same volume tank while lowering the vapor pressure and thus the tank operating pressure. Lowering the tank operating pressure reduces the stress and therefore allows the walls of the tank to be thinner. Both the smaller tank volume and thinner tank wall results in an overall smaller and lighter vehicle with increased payload capability. The cryogenic propellant can be supercooled well below the normal boiling point temperature level by transporting the liquid propellant from the vehicle tanks to a ground based cooling unit which utilizes a combination of heat exchanger and compressor. The compressor lowers the coolant fluid bath pressure resulting in a low temperature boiling liquid which is subsequently used to cool the recirculating liquid. The cooled propellant is then returned to the vehicle propellant tank. In addition to reducing the vehicle size and weight the invention also allows location of the vent valve on the ground, elimination of on-board recirculation pumps or bleed systems, smaller and lighter engine pumps and valves, lighter and more stable ullage gas, and significant reduction in tank fill operation. All of these mentioned attributes provide lower vehicle weight and cost.

Liquid propellant densification

The fluid management system comprises a mixing/recirculation system including an external recirculation pump for receiving fluid from a zero gravity storage system and returning an output flow of the fluid to the storage system. An internal axial spray injection system is provided for receiving a portion of the output flow from the recirculation pump. The spray injection system thermally de-stratifies liquid and gaseous cryogenic fluid stored in the storage system.

Fluid management system for a zero gravity cryogenic storage system

A computer program is disclosed for specifying and solving a fluid transfer problem. Schematic manager means are provided for generating and modifying a pictorial representation of a fluid system schematic having a plurality of components. The schematic manager means Is fluid and process independent. Replicator means are provided for generating a set of simultaneous equations from the pictorial representation and for assuring that the schematic manager remains fluid and process independent. A generic run-time simulation module is provided for solving the set of simultaneous equations, thereby allowing the computer program to adapt to variations in component state and fluid state as a function of system parameters. A fluid and property database manager is invoked by the simulation module, for allowing simulation of fluid flow processes having fluid states which may be unknown at the time of model creation. The data display routine is provided for displaying program results, thereby obviating any requirement for user coding.

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Huntington Beach, CA, United States of America

Tibor I Lak