Inflated cylindrical solar concentrator for producing industrial process heat

Technical Report · Mon Dec 19 04:00:00 EST 1977

OSTI ID:6789971

Gerich, J W

The use of industrial process heat below 170/sup 0/C accounts for 5% of this country's total energy consumption. A concentrating solar collector to produce hot water and steam in this temperature range is under development. The collector structure consists mainly of an inflated thin-film plastic cylinder that is clear on the upper portion and is an aluminized reflector on the lower portion. The reflector concentrates sunlight on a receiver tube which is jacketed with a heat transfer suppressing, thin-film plastic cylinder. Because of its simplicity, it is believed this collector will be cost-effective relative to fossil fuels such as oil at $15/bbl. Computer codes were written to analyze the optical and thermal properties of this collector. Results indicate that weekly tilting of the collector provides over 90% of the energy available from continuous tracking. A selective surface on the receiver tube (..cap alpha.. = 0.92, epsilon = 0.20) increases the useful energy gain by more than a factor of five at 170/sup 0/C. The stagnation temperature at the outer receiver tube surface is calculated to be below 350/sup 0/C. Combining calculated optical and thermal efficiencies gives an overall collector efficiency of 20% for 170/sup 0/C operation. This figure is based on an aperture of the full diameter times the length, and on beam radiation. The first experimental collectors are being constructed to verify our computer code studies. These units are 4 m long with an outer diameter of 1 m.

• Research Organization: California Univ., Livermore (USA). Lawrence Livermore Lab.
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6789971
• Report Number(s): UCID-17612(Rev.1)
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140905*
141000 -- Solar Collectors & Concentrators
COMPUTER CALCULATIONS
CONCENTRATING COLLECTORS
CONFIGURATION
CYLINDRICAL CONFIGURATION
DESIGN
EFFICIENCY
ENERGY
ENERGY TRANSFER
HEAT
HEAT TRANSFER
INDUSTRY
PERFORMANCE
PETROCHEMICALS
PETROLEUM PRODUCTS
PLASTICS
PROCESS HEAT
SOLAR COLLECTORS
SOLAR CONCENTRATORS
SOLAR PROCESS HEAT
SOLAR TRACKING
SPECTRALLY SELECTIVE SURFACES
SURFACES