Experimental natural convective studies within a compound parabolic concentrator enclosure

Technical Report · Sat Jan 01 04:00:00 EST 1983

OSTI ID:5043836

Tatara, R A; Thodos, G

The contribution due to natural convection within a compound parabolic concentrator enclosure has been experimentally determined. These studies have been conducted within a 4X-CPC collector, having a receiver width of 3.175 cm (1.25 inches) and 2.44 m (96 inches) in length. The receiver was heated electrically while the aperture was provided with a duct that was cooled by water. The limbs of the collector were fabricated from aluminum. Temperatures were directly obtained with copper-constantan thermocouples located throughout the entire enclosure and provided the basis needed to calculate the different modes of heat transfer. The constant heat flux at the receiver translated to a nearly isothermal state. The rates of natural convection have been expressed in terms of a Nu-Ra correlation where 1.0x10/sup 7/ < Ra < 4.0x10/sup 7/. To suppress natural convection, a horizontal partition was introduced at different heights between the receiver and aperture. These results have been expressed as heat fluxes and temperature differences between the receiver and the aperture. This information made possible a comparison between the aperture-partition enclosure and a flat plate geometry.

• Research Organization: Northwestern Univ., Evanston, IL (USA)
• DOE Contract Number: FG02-80CS84054
• OSTI ID: 5043836
• Report Number(s): DOE/CS/84054-T1; ON: DE84006967
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
141000* -- Solar Collectors &amp; Concentrators
COMPOUND PARABOLIC CONCENTRATORS
CONVECTION
COVERINGS
ENERGY LOSSES
EQUIPMENT
HEAT FLUX
HEAT LOSSES
HEATING
LOSSES
NATURAL CONVECTION
SOLAR CONCENTRATORS
SOLAR EQUIPMENT