Internal absorber solar collector

Patent · Tue Dec 29 00:00:00 EST 1981

OSTI ID:5717245

Herskovitz, S B; Holt, F S; Sletten, C J; Sletten, E J

Thin solar collecting panels are described made from arrays of small rod collectors consisting of a refracting dielectric rod lens with an absorber imbedded within it and a reflecting mirror coated on the back side of the dielectric rod. Non-tracking collector panels on vertical walls or roof tops receive approximately 90% of solar radiation within an acceptance zone 60/sup 0/ in elevation angle by 120/sup 0/ or more in the azimuth secto with a collector concentration ratio of approximately 3.0. Miniaturized construction of the circular dielectric rods with internal absorbers reduces the weight per area of glass, plastic and metal used in the collector panels. No external parts or insulation are needed as heat losses are low due to partial vacuum or low conductivity gas surrounding heated portions of the collector. The miniature internal absorbers are generally made of solid copper with black selective surface and the collected solar heat is extracted at the collector ends by thermal conductivity along the absorber rods. Heat is removed from end fittings by use of liquid circulants. Several alternate constructions are provided for simplifying collector panel fabrication and for preventing the thermal expansion and contraction of the heated absorber or circulant tubes from damaging vacuum seals. In a modified version of the internal absorber collector, oil with temperature dependent viscosity is pumped through a segmented absorber which is now composed of closely spaced insulated metal tubes. In this way the circulant is automatically diverted through heated portions of the absorber giving higher collector concentration ratios than theoretically possible for an unsegmented absorber.

• Assignee: IFI; EDB-82-076859
• Patent Number(s): US 4307709
• OSTI ID: 5717245
• Resource Relation: Patent File Date: Filed date 17 Jan 1980; Other Information: PAT-APPL-112953
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
SOLAR COLLECTORS
LENSES
SOLAR ABSORBERS
BLACK COATINGS
COPPER
DIELECTRIC MATERIALS
GASES
HEAT TRANSFER FLUIDS
MIRRORS
SPECTRALLY SELECTIVE SURFACES
THERMAL CONDUCTIVITY
TUBES
VACUUM SYSTEMS
COATINGS
ELEMENTS
EQUIPMENT
FLUIDS
MATERIALS
METALS
PHYSICAL PROPERTIES
SOLAR EQUIPMENT
SURFACES
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENTS
141000* - Solar Collectors & Concentrators