Boiling behavior of sodium-potassium alloy in a bench-scale solar receiver
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, Washington, DC (United States)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 10149102
- 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; Other Information: PBD: [1992]
- Country of Publication:
- United States
- Language:
- English
Similar Records
Bench-scale screening tests for a boiling sodium-potassium alloy solar receiver
First on-sun test of NaK-78 pool-boiler solar receiver
Related Subjects
36 MATERIALS SCIENCE
SODIUM ALLOYS
MATERIALS TESTING
POTASSIUM ALLOYS
SOLAR RECEIVERS
WORKING FLUIDS
BENCH-SCALE EXPERIMENTS
STIRLING ENGINES
SOLAR THERMAL CONVERSION
BOILING
BOILERS
140700
141000
360104
SOLAR THERMAL POWER SYSTEMS
SOLAR COLLECTORS AND CONCENTRATORS
PHYSICAL PROPERTIES