Thermal modeling of solar central receiver cavities

Conference · Fri Jan 01 04:00:00 EST 1988

OSTI ID:5427248

Skocypec, R D; Romero, V

Results are presented from a numerical model of the steady-state energy transfer in molten-salt-in-tube solar cavity receivers that includes convective energy transfer at a local (spatially resolved) level. Molten salt energy absorption and gray radiative transfer between all cavity surfaces are also included. This model is applied to the MSS/CTE cavity receiver. Results for this receiver indicate the global receiver thermal efficiency is invariant within a few percent to most parameters investigated, although front surface temperatures of the nonabsorbing walls vary considerably, and are particularly sensitive to the type of convective submodel used. Absorption efficiencies indicate the effects of the cavity enclosure environment. For all conditions investigated, tube inner wall temperatures remain under 855 K, ensuring that the salt remains chemically stable. Global (entire cavity) results for the receiver indicate thermal conditions in the receiver are temporally constant within an hour of solar noon, and solar panel temperatures are governed by the temperature of the flowing salt (the outlet temperature is maintained at 839 K by varying the salt mass flowrate). The dominant loss mechanism is radiative transfer, although convective loss predictions are of the same order of magnitude. The absorbing panel front surface temperatures and the panel thermal losses are somewhat invariant with incident flux. Losses from the nonabsorbing surfaces (comprising over 60% of the cavity surface area), however, do vary with incident flux levels. These results suggest that a correction for nonconstant losses in the Barron flux-on loss method is necessary. 10 refs., 9 figs., 1 tab.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 5427248
• Report Number(s): SAND-87-1569C; CONF-880457-3; ON: DE88004940
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140702* -- Solar Thermal Power Systems-- Central Receiver
CENTRAL RECEIVERS
COMPUTER CODES
DATA
ENERGY TRANSFER
H CODES
HEAT TRANSFER
INFORMATION
MATHEMATICAL MODELS
MOLTEN SALTS
NUMERICAL DATA
SALTS
SOLAR RECEIVERS
TEMPERATURE DISTRIBUTION
THEORETICAL DATA