Boiling behavior of sodium-potassium alloy in a bench-scale solar receiver

Conference · Wed Jan 01 00:00:00 EST 1992

OSTI ID:5284732

Moreno, J B; Andraka, C E; Moss, T A

During 1989-90, a 75-kW{sub t} sodium reflux pool-boiler solar receiver was successfully demonstrated at Sandia National Laboratories. Significant features of this receiver include (1) boiling sodium as the heat transfer medium and (2) electric-discharge-machined (EDM) cavities as artificial nucleation sites to stabilize boiling. Since this first demonstration, design of a second-generation pool-boiler receiver that will bring the concept closer to commercialization has begun. For long life, the new receiver uses Haynes Alloy 230. For increased safety factors against film boiling and flooding, it has a refined shape and somewhat larger dimensions. To eliminate the need for trace heating, the receiver will boil the sodium-potassium alloy NaK-78 instead of sodium. To reduce manufacturing costs, it will use one of a number of alternatives to EDM cavities for stabilization of boiling. To control incipient-boiling superheats, especially during hot restarts, it will contain a small amount of inert gas. Before the new receiver design could be finalized, bench-scale tests of some of the proposed changes were necessary. A series of bench-scale pool boilers were built from Haynes Alloy 230 and filled with NaK-78. Various boiling-stabilizer candidates were incorporated into them, including laser-drilled cavities and a number of different sintered-powder-metal coatings. These bench-scale pool boilers have been operated at temperatures up to 750{degree}C, heated by quartz lamps with incident radiant fluxes up to 95 W/cm{sup 2}. The effects of various orientations and added gases have been studied. results of these studies are presented. 15 refs.

• Research Organization: Sandia National Labs., Albuquerque, NM (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 5284732
• Report Number(s): SAND-91-2801C; CONF-920801-3; ON: DE92014947
• Resource Relation: Conference: 27. intersociety energy conversion engineering conference, San Diego, CA (United States), 3-7 Aug 1992
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
POTASSIUM ALLOYS
MATERIALS TESTING
SODIUM ALLOYS
SOLAR RECEIVERS
WORKING FLUIDS
BENCH-SCALE EXPERIMENTS
BOILERS
BOILING
SOLAR THERMAL CONVERSION
STIRLING ENGINES
ALLOYS
CONVERSION
ENERGY CONVERSION
ENGINES
FLUIDS
HEAT ENGINES
PHASE TRANSFORMATIONS
SOLAR ENERGY CONVERSION
TESTING
140700* - Solar Thermal Power Systems
141000 - Solar Collectors & Concentrators
360104 - Metals & Alloys- Physical Properties