Bench-scale screening tests for a boiling sodium-potassium alloy solar receiver
Abstract
Bench-scale tests were carried out in support of the design of a second-generation 75-kW{sub t} reflux pool-boiler solar receiver. The receiver will be made from Haynes Alloy 230 and will contain the sodium-potassium alloy NaK-78. The bench-scale tests used quartz-lamp-heated boilers to screen candidate boiling-stabilization materials and methods at temperatures up to 750{degree}C. Candidates that provided stable boiling were tested for hot-restart behavior. Poor stability was obtained with single 1/4-inch diameter patches of powdered metal hot-press-sintered onto the wetted side of the heat-input area. Laser-drilled and electric-discharge-machined cavities in the heated surface also performed poorly. Small additions of xenon, and heated-surface tilt out of the vertical dramatically improved poor boiling stability; additions of helium or oxygen did not. The most stable boiling was obtained when the entire heat-input area was covered by a powdered-metal coating. The effect of heated-area size was assessed for one coating: at low incident fluxes, when even this coating performed poorly, increasing the heated-area size markedly improved boiling stability. Good hot-restart behavior was not observed with any candidate, although results were significantly better with added xenon in a boiler shortened from 3 to 2 feet. In addition to the screening tests, flash-radiography imaging of metal-vapor bubblesmore »
- Authors:
- Publication Date:
- Research Org.:
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
- Sponsoring Org.:
- USDOE, Washington, DC (United States)
- OSTI Identifier:
- 10175668
- Report Number(s):
- SAND-92-2253
ON: DE93018512; TRN: AHC29307%%10
- DOE Contract Number:
- AC04-76DP00789
- Resource Type:
- Technical Report
- Resource Relation:
- Other Information: PBD: Jun 1993
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 14 SOLAR ENERGY; 36 MATERIALS SCIENCE; CAVITY RECEIVERS; DESIGN; SODIUM ALLOYS; BOILING; STABILITY; POTASSIUM ALLOYS; MATERIALS TESTING; BENCH-SCALE EXPERIMENTS; START-UP; XENON; HELIUM; OXYGEN; ADDITIVES; COATINGS; BUBBLES; SIZE; OPERATION; LIQUID METALS; COST; SERVICE LIFE; HEAT TRANSFER; TEST FACILITIES; PRESSURE MEASUREMENT; INDUSTRIAL RADIOGRAPHY; EXPERIMENTAL DATA; CSP; Concentrating Solar Power; 141000; 360104; SOLAR COLLECTORS AND CONCENTRATORS; PHYSICAL PROPERTIES
Citation Formats
Moreno, J B, and Moss, T A. Bench-scale screening tests for a boiling sodium-potassium alloy solar receiver. United States: N. p., 1993.
Web. doi:10.2172/10175668.
Moreno, J B, & Moss, T A. Bench-scale screening tests for a boiling sodium-potassium alloy solar receiver. United States. https://doi.org/10.2172/10175668
Moreno, J B, and Moss, T A. 1993.
"Bench-scale screening tests for a boiling sodium-potassium alloy solar receiver". United States. https://doi.org/10.2172/10175668. https://www.osti.gov/servlets/purl/10175668.
@article{osti_10175668,
title = {Bench-scale screening tests for a boiling sodium-potassium alloy solar receiver},
author = {Moreno, J B and Moss, T A},
abstractNote = {Bench-scale tests were carried out in support of the design of a second-generation 75-kW{sub t} reflux pool-boiler solar receiver. The receiver will be made from Haynes Alloy 230 and will contain the sodium-potassium alloy NaK-78. The bench-scale tests used quartz-lamp-heated boilers to screen candidate boiling-stabilization materials and methods at temperatures up to 750{degree}C. Candidates that provided stable boiling were tested for hot-restart behavior. Poor stability was obtained with single 1/4-inch diameter patches of powdered metal hot-press-sintered onto the wetted side of the heat-input area. Laser-drilled and electric-discharge-machined cavities in the heated surface also performed poorly. Small additions of xenon, and heated-surface tilt out of the vertical dramatically improved poor boiling stability; additions of helium or oxygen did not. The most stable boiling was obtained when the entire heat-input area was covered by a powdered-metal coating. The effect of heated-area size was assessed for one coating: at low incident fluxes, when even this coating performed poorly, increasing the heated-area size markedly improved boiling stability. Good hot-restart behavior was not observed with any candidate, although results were significantly better with added xenon in a boiler shortened from 3 to 2 feet. In addition to the screening tests, flash-radiography imaging of metal-vapor bubbles during boiling was attempted. Contrary to the Cole-Rohsenow correlation, these bubble-size estimates did not vary with pressure; instead they were constant, consistent with the only other alkali metal measurements, but about 1/2 their size.},
doi = {10.2172/10175668},
url = {https://www.osti.gov/biblio/10175668},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Jun 01 00:00:00 EDT 1993},
month = {Tue Jun 01 00:00:00 EDT 1993}
}