Heat exchanger for electrothermal devices

Patent · Tue Sep 02 00:00:00 EDT 1986

OSTI ID:5286973

Zavesky, R J; Sovey, J S; Mirtich, M J; Marinos, C; Penko, P F

A heat exchanger is described for heating a gaseous propellant to a temperature between about 200/sup 0/C and about 2200/sup 0/C in an electrothermal thruster having a nozzle comprising a hollow housing forming a cylindrical chamber adjacent to the nozzle, the hollow housing having a textured inner surface to provide high absorptivity and an oppositely disposed textured outer surface to provide high emissivity, an outer housing surrounding the cylindrical chamber in spaced relationship thereto thereby forming an annular chamber for conducting the gaseous propellant to the nozzle, a porous heat exchanger material selected from the group consisting of refractories, ceramics, and cermets contained within the annular chamber, housing a wire coiled about the outer surface of the hollow housing in engagement with the outer housing for providing a lengthened spiral flow path for the propellant to the annular chamber, an electrical heating comprising a coiled tube having a wall thickness of about 0.25 mm and a textured surface for providing high emissivity mounted within the cylindrical chamber in spaced relationship with the textured inner surface for radiatively heating the hollow housing and heat exchanger material without contacting the gaseous propellant, means for supplying a gaseous propellant to the lengthened spiral flow path and seal annular chamber whereby the propellant is uniformly heated by the hollow housing and the porous heat exchanger material as it flows therethrough in a minimum gas path length, and a thermal choke formed in the electrical heating element adjacent to the coiled wire for reducing conducted thermal energy.

• Assignee: NASA, Washington, DC
• Patent Number(s): US 4608821
• OSTI ID: 5286973
• Resource Relation: Patent File Date: Filed date 31 Jul 1984
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
42 ENGINEERING
HEAT EXCHANGERS
DESIGN
OPERATION
PROPELLANTS
ELECTRIC HEATING
THRUSTERS
ABSORPTION
CERAMICS
CERMETS
GAS FUELS
HIGH TEMPERATURE
NOZZLES
POROUS MATERIALS
REFRACTORIES
SPACE DEPENDENCE
TEXTURE
THICKNESS
VERY HIGH TEMPERATURE
WIRES
COMPOSITE MATERIALS
DIMENSIONS
FUELS
HEATING
MATERIALS
320201* - Energy Conservation
Consumption
& Utilization- Transportation- Air & Aerospace
421000 - Engineering- Combustion Systems