Heat-pipe development for high-temperature recuperator application

Conference · Thu Jan 01 04:00:00 EST 1981

DOI:https://doi.org/10.1016/B978-0-08-027284-9.50028-0· OSTI ID:6460510

Merrigan, M; Dunwoody, W; Lundberg, L

Heat pipes have been developed for operation in oxidizing atmospheres at temperatures above 1100/sup 0/K. The heat pipes comprise a metallic liner and wick structure with a protective outer shell of an oxidation resistant material. The working fluids used in the heat pipes are alkali metals. A number of configurations have been evaluated, ranging from pipes using a metallic inner liner of a chemically vapor deposited (CVD) refractory metal applied to ceramic tubing, to one utilizing ferrous materials with an outer layer of a developed oxide. A promising intermediate configuration consisting of free-standing refractory tubing covered with a layered structure of fine grain, equi-axed CVD silicon carbide has also been evaluated. The test heat pipe was fabricated using low-carbon, arc-cast molybdenum tubing and a wick composed of 150 mesh molybdenum screen. Hafnium gettering was used with sodium working fluid. Assembly of the pipe was by electron beam welding. Following closure and capping of the fill tube the assembly was operated in a vacuum for several hours prior to the chemical vapor deposition of the exterior ceramic coating. After coating, the pipe was operated in air and in combustion gases for performance evaluation. The use of iron-chromium-aluminum alloys as container materials for operating in high temperature oxidizing and sulfiding gas streams has been investigated. Alloys of this type develop heavy, protective oxide surface layers when exposed to high temperature oxidizing atmospheres, and are commonly used in electrical heating elements because of their exceptional oxidation resistance.

• Research Organization: Los Alamos National Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6460510
• Report Number(s): LA-UR-81-1414; CONF-810902-4
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
320304 -- Energy Conservation
Consumption
& Utilization-- Industrial & Agricultural Processes-- Waste Heat Recovery & Utilization
42 ENGINEERING
420200* -- Engineering-- Facilities
Equipment
& Techniques
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
AROMATICS
CARBIDES
CARBON COMPOUNDS
CERAMICS
CHALCOGENIDES
DATA
DESIGN
EQUIPMENT
EXPERIMENTAL DATA
FABRICATION
HEAT EXCHANGERS
HEAT PIPES
HEAT RECOVERY EQUIPMENT
HYDROCARBONS
INFORMATION
NUMERICAL DATA
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PERFORMANCE
SILICON CARBIDES
SILICON COMPOUNDS
TOLUENE
VERY HIGH TEMPERATURE