Accession Number:

ADA193726

Title:

Solar Energy Absorption Efficiency of an Ellipsoidal Receiver-Reactor with Specularly Reflecting Walls

Descriptive Note:

Technical rept. 31 Oct 1986-31 Mar 1989

Corporate Author:

MINNESOTA UNIV MINNEAPOLIS DEPT OF MECHANICAL ENGINEERING

Personal Author(s):

• Steinfeld, A.
• Fletcher, E. A.

Report Date:

1988-04-05

Pagination or Media Count:

20.0

Abstract:

An ellipsoidal cavity-receiver with specularly reflecting inner walls, in which the reactor component is positioned at one focal point and the aperture at the other, may be useful in solar applications. Most of the incident radiation from a solar concentrator should reach the reactor directly or after one reflection from the cavity walls. Because the source aperture and sink reactor have finite areas, the ellipsoidal reflector no longer conveys all of the entering radiation into the reactor some radiation entering the cavity does not reach the target after one reflection and is eventually absorbed by the cavity walls after multiple reflections or escapes through the aperture. We have examined the conditions for which this radiation loss becomes significant and have estimated the effects on the energy-collection efficiency of the system. Keywords Solar furnaces Solar electrothermal receiver-reactors.

Descriptors:

• *SOLAR COLLECTORS
• *SOLAR FURNACES
• REFLECTION
• ELLIPSOIDS
• SOLAR ENERGY
• RECEIVERS
• WALLS
• LOSSES
• SOLAR RADIATION
• REFLECTORS
• ENERGY ABSORBERS
• SPECULAR REFLECTION
• CAVITIES
• RADIATION
• EFFICIENCY

Subject Categories:

• Air Conditioning, Heating, Lighting and Ventilating

Distribution Statement:

APPROVED FOR PUBLIC RELEASE