Abstract: A cooling system uses refrigerants for two-phase cooling and thermal energy storage for a transient heat source. The cooling system includes a flash tank downstream of a heat load to be cooled. A subcooler/super-heater is downstream of the flash tank. A compressor is downstream of the subcooler/super-heater. A condenser is downstream of the compressor and upstream of the flash tank.

Abstract: A cooling system uses refrigerants for two-phase cooling and thermal energy storage for a transient heat source. The cooling system includes a flash tank downstream of a heat load to be cooled. A subcooler/super-heater is downstream of the flash tank. A compressor is downstream of the subcooler/super-heater. A condenser is downstream of the compressor and upstream of the flash tank.

Abstract: An environmental control system (ECS) includes an air cycle machine with an expansion turbine and a condenser having a cold air inlet connected to receive air from the expansion turbine. The condenser has hollow, internally finned hot bars positioned at the cold air inlet to prevent ice formation at the cold air inlet.

Abstract: A heat exchanger fin capable of increasing convective heat transfer by reducing internal conduction along an undesirable direction within the heat exchanger fin itself is disclosed. More specifically, the current invention reduces conduction within the heat exchanger fin along an undesirable direction along the direction of fluid flow because such conduction decreases the performance of the heat exchanger fin. A heat exchanger fin in accordance with the present invention utilizes a plurality of notches within the heat exchanger fin that is perpendicular to the direction of fluid flow to increase the resistance of conduction within the heat exchanger fin itself. By increasing the resistance of conduction in an undesired direction, the heat exchanger fin is capable of more uniform temperature to along the entire surface area to facilitate increase convective heat transfer in the desired direction.

Abstract: Methods and apparatus for controlling tube temperatures may prevent freezing of fluids in cross counterflow shell and tube heat exchangers. Cold gas may flow inside the tubes of the heat changer and warm liquid may flow outside the tubes. The tube diameter and tube spacing may be varied through the tube passes through the heat exchanger in order to provide a hot side conductance to cold side conductance ratio which results in the tube temperature being safely above the liquid freezing point. The heat exchanger may be used in, for example, the aerospace industry as a fuel oil cooler or as a preconditioner for reactants in a spacecraft propulsion system.

Abstract: A heat exchanger fin capable of increasing convective heat transfer by reducing internal conduction along an undesirable direction within the heat exchanger fin itself is disclosed. More specifically, the current invention reduces conduction within the heat exchanger fin along an undesirable direction along the direction of fluid flow because such conduction decreases the performance of the heat exchanger fin. A heat exchanger fin in accordance with the present invention utilizes a plurality of notches within the heat exchanger fin that is perpendicular to the direction of fluid flow to increase the resistance of conduction within the heat exchanger fin itself. By increasing the resistance of conduction in an undesired direction, the heat exchanger fin is capable of more uniform temperature to along the entire surface area to facilitate increase convective heat transfer in the desired direction.