摘要:
Heat generated, for example, in a spacecraft under zero gravity conditions and different accelerations is discharged through an evaporation heat exchanger connected to at least one active coolant circulation circuit. The heat exchanger has a bundle of tubes axially arranged inside a cylindrical processing chamber. An evaporant passes through these tubes. A coolant flows into heat exchange contact with outer surfaces of said tubes. The outlet cross-sectional flow area for the evaporant, or rather its vapor, is variable so that the pressure of the evaporated medium, and thereby also its evaporation temperature are adjustable. The adjustment of the cross-sectional flow area for the vapor is controlled in response to the temperature of the cooling liquid or coolant where it enters into a processing chamber of the heat exchanger. Selectively closable apertures in an end plate (52) serve for changing the outlet cross-section flow area for the vapor. The apertures are, at least partially, closable by flaps which are controlled by bimetal springs responsive to the temperature of the entering coolant.
摘要:
Water coolant circulating in a closed loop may be cooled by passing it through a heat exchanger coil embedded within a block of heavy water ice. The ice will maintain the water, passing through the coil, at a temperature approximately 39.degree. F. Maintenance of the working fluid at this temperature prevents it from freezing in coolant tubes. The system is particularly adapted for a liquid cooling space garment which must effectively conduct away heat from an astronaut's body when an astronaut exerts himself during physical activity.
摘要:
A fluid ejection nozzle is disclosed which facilitates a wide distribution of fluid therefrom and which permits the fluid flow rate to be easily adjustable. The nozzle is particularly adapted to a heat rejection system useful in a space environment. The nozzle includes a flow distributor positioned within an orifice of the nozzle housing which is comprised of a tongue member and an attached flow control block. Adjustment screws mounted through the nozzle housing permit axial movement of the flow distributor within the housing, thus controlling the flow rate of the fluid even to the extent of total shut-off. The tongue member is shaped to widely disperse the fluid, and includes turbulence generators such as roughening or ridges for facilitating its dispersion.
摘要:
A two-phase capillary pumped loop heat transfer system adapted primarily for use on space vehicles, includes a wickless condenser tube which receives gaseous phase working fluid from the evaporator capillaries, rejects heat from the working fluid to a heat sink (e.g. outer space) and thereby converts the gaseous phase working fluid to its liquid phase, and returns the liquid phase working fluid to the evaporator to complete the thermal cycle. A portion of the condenser tube is supported by a rigid radiator structure external to the spacecraft. At least a portion of the condenser tube is deformable to permit the radiator structure to be deployed from a first predetermined position to a second predetermined position with respect to the spacecraft. The deformable segment of the condenser tube can be formed into a helical coil used as a spring to assist deployment of the radiator panel.
摘要:
Composite flexible multilayer insulation systems (MLI) were evaluated for thermal performance and compared with currently used fibrous silica (baseline) insulation system. The systems described are multilayer insulations consisting of alternating layers of metal foil and scrim ceramic cloth or vacuum metallized polymeric films quilted together using ceramic thread. A silicon carbide thread for use in the quilting and the method of making it are also described. These systems are useful to provide lightweight thermal insulation for a variety of uses, particularly on the surface of aerospace vehicles subject to very high temperatures during flight.
摘要:
A closed-loop two-phase thermal control loop includes an evaporator which receives subcooled coolant liquid from a condenser and heat from a source, and vaporizes the coolant to form coolant vapor. A condenser which is coupled to a thermal radiator accepts the coolant vapor and radiates thermally to space, thereby condensing the coolant vapor to liquid and subcooling the liquid. As the temperature of the environment surrounding the condenser radiator changes, the mass of vapor within the system tends to change, thereby causing undesirable pressure changes. A spherical wicked coolant reservoir is coupled to the liquid side of the closed thermal control loop. The reservoir is exposed foro thermal radiation and electrically heated, so that the temperature is thereby controlled in order to control vapor pressure within the reservoir. By controlling the reservoir vapor pressure, small pressure differentials are generated, which cause coolant liquid to be accepted or expelled while maintaining the closed loop pressure. The reservoir includes a wick for maintaining liquid coolant adjacent heat transfer areas, and also includes a standpipe supporting shaped vanes. The coolant adheres to the vanes and to the wick under zero-gravity conditions in a manner which allows at least partial simulation in an Earth gravity.
摘要:
A method and composition which provides both thermal; control and electrostatic discharge protection to bodies in the space environment. The composition comprises: (a) a chosen polymer or resin that forms a polymer that is an electronic insulator and is suitable for space applications; and (b) a selected lithium salt as a dopant wherein said composition, when formed into a film or coating, provides a semiconductive film or coating having a volume resistivity of about 10.sup.6 to 10.sup.11 ohm-centimeter and a value of solar absorptance/total normal emittance within the range of about 0.305 to 0.595. In an alternative embodiment, the composition may optionally include tantalum pentoxide.
摘要:
A thermal management system for a spacecraft includes a plurality of T-shaped pallets each having a radiator panel and mounting panel. The radiator panels are connected end to end to enclose an interior space including the mounting panels. The mounting panels have electronic equipment mounted thereon. L-shaped external heat pipes contact both the mounting panel and radiator panel of each pallet to provide heat transfer from the electronic equipment to the radiator panel when the radiator panel is facing away from the sun. In order to cool the electronic equipment mounted on a pallet facing the sun, a closed-loop heat pipe is disposed in the interior space and each pallet inclues L-shaped internal heat pipes contacting the closed-loop heat pipe and the mounting panel. Heat generated in the electronic equipment of the pallet facing the sun is transferred to the internal heat pipes via the mounting panel and then to the closed-loop heat pipe. The heat then is transferred to the radiator panels facing away from the sun via the closed-loop heat pipe, the internal heat pipes, the mounting panels, and the external heat pipes. In one embodiment, the mounting panels are comprised of a pair of spaced-apart mounting plates, and the legs of the external and internal L-shaped heat pipes contacting the mounting panel are disposed within this space separating the mounting plates.
摘要:
A deployment system for controlling unfolding kinematics of radiator panels 26 of a space power system. The deployment system includes a plurality of forming mandrels 30 associated with a housing 38 of opposing generally triangular plates 40. Within the housing, a drive wheel 52 and two additional guide wheels 50 interact with the mandrels to effect predetermined deflection and deployment of the multiple radiator panels.