Sodium reflux pool-boiler solar receiver on-sun test results
Abstract
The efficient operation of a Stirling engine requires the application of a high heat flux to the relatively small area occupied by the heater head tubes. Previous attempts to couple solar energy to Stirling engines generally involved directly illuminating the heater head tubes with concentrated sunlight. In this study, operation of a 75-kW{sub t} sodium reflux pool-boiler solar receiver has been demonstrated and its performance characterized on Sandia's nominal 75-kW{sub t} parabolic-dish concentrator, using a cold-water gas-gap calorimeter to simulate Stirling engine operation. The pool boiler (and more generally liquid-metal reflux receivers) supplies heat to the engine in the form of latent heat released from condensation of the metal vapor on the heater head tubes. The advantages of the pool boiler include uniform tube temperature, leading to longer life and higher temperature available to the engine, and decoupling of the design of the solar absorber from the engine heater head. The two-phase system allows high input thermal flux, reducing the receiver size and losses, therefore improving system efficiency. The receiver thermal efficiency was about 90% when operated at full power and 800{degree}C. Stable sodium boiling was promoted by the addition of 35 equally spaced artificial cavities in the wetted absorbermore »
- Authors:
-
- Oak Ridge National Lab., TN (United States)
- Publication Date:
- Research Org.:
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
- Sponsoring Org.:
- USDOE; USDOE, Washington, DC (United States)
- OSTI Identifier:
- 7239599
- Report Number(s):
- SAND-89-2773
ON: DE92018932
- DOE Contract Number:
- AC04-76DP00789
- Resource Type:
- Technical Report
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 14 SOLAR ENERGY; CENTRAL RECEIVERS; STIRLING ENGINES; PERFORMANCE TESTING; LATENT HEAT STORAGE; PARABOLIC DISH COLLECTORS; SODIUM; SOLAR HEAT ENGINES; SOLAR THERMAL CONVERSION; ALKALI METALS; CONCENTRATING COLLECTORS; CONVERSION; ELEMENTS; ENERGY CONVERSION; ENERGY STORAGE; ENGINES; EQUIPMENT; HEAT ENGINES; HEAT STORAGE; METALS; PARABOLIC COLLECTORS; SOLAR COLLECTORS; SOLAR ENERGY CONVERSION; SOLAR EQUIPMENT; SOLAR RECEIVERS; STORAGE; TESTING; CSP; Concentrating Solar Power; 140702* - Solar Thermal Power Systems- Central Receiver
Citation Formats
Andraka, C E, Moreno, J B, Diver, R B, and Moss, T A. Sodium reflux pool-boiler solar receiver on-sun test results. United States: N. p., 1992.
Web. doi:10.2172/7239599.
Andraka, C E, Moreno, J B, Diver, R B, & Moss, T A. Sodium reflux pool-boiler solar receiver on-sun test results. United States. https://doi.org/10.2172/7239599
Andraka, C E, Moreno, J B, Diver, R B, and Moss, T A. 1992.
"Sodium reflux pool-boiler solar receiver on-sun test results". United States. https://doi.org/10.2172/7239599. https://www.osti.gov/servlets/purl/7239599.
@article{osti_7239599,
title = {Sodium reflux pool-boiler solar receiver on-sun test results},
author = {Andraka, C E and Moreno, J B and Diver, R B and Moss, T A},
abstractNote = {The efficient operation of a Stirling engine requires the application of a high heat flux to the relatively small area occupied by the heater head tubes. Previous attempts to couple solar energy to Stirling engines generally involved directly illuminating the heater head tubes with concentrated sunlight. In this study, operation of a 75-kW{sub t} sodium reflux pool-boiler solar receiver has been demonstrated and its performance characterized on Sandia's nominal 75-kW{sub t} parabolic-dish concentrator, using a cold-water gas-gap calorimeter to simulate Stirling engine operation. The pool boiler (and more generally liquid-metal reflux receivers) supplies heat to the engine in the form of latent heat released from condensation of the metal vapor on the heater head tubes. The advantages of the pool boiler include uniform tube temperature, leading to longer life and higher temperature available to the engine, and decoupling of the design of the solar absorber from the engine heater head. The two-phase system allows high input thermal flux, reducing the receiver size and losses, therefore improving system efficiency. The receiver thermal efficiency was about 90% when operated at full power and 800{degree}C. Stable sodium boiling was promoted by the addition of 35 equally spaced artificial cavities in the wetted absorber surface. High incipient boiling superheats following cloud transients were suppressed passively by the addition of small amounts of xenon gas to the receiver volume. Stable boiling without excessive incipient boiling superheats was observed under all operating conditions. The receiver developed a leak during performance evaluation, terminating the testing after accumulating about 50 hours on sun. The receiver design is reported here along with test results including transient operations, steady-state performance evaluation, operation at various temperatures, infrared thermography, x-ray studies of the boiling behavior, and a postmortem analysis.},
doi = {10.2172/7239599},
url = {https://www.osti.gov/biblio/7239599},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Jun 01 00:00:00 EDT 1992},
month = {Mon Jun 01 00:00:00 EDT 1992}
}