Investigation of a parallel glass sheet honeycomb solar collector concept
This study investigated the use of a parallel glass sheet honeycomb to control free convective and radiative losses and improve thermal performance of a flat plate solar collector. Two parallel glass sheet honeycomb assemblies were designed to fit between a water-cooled, non-selective black solar absorber and a single coverglass in an experimental flat plate solar collector, with aperture dimensions 0.61 m x 0.61 m. Corning Glass Works microsheet, 0.03 cm thick was used to form the parallel slot structures: one with slot spacing (d/sub i/) 0.635 cm and aspect ratio (L/d/sub i/) = 12, the other with d/sub i/ = 0.476 cm and L/d/sub i/ = 13.3. Measurements were made to determine the solar transmittance of the 0.476 cm array as a function of solar incidence angles, and laboratory tests were performed in a special calorimeter with a reduced scale array to determine the Nusselt-Rayleigh number relationship for the honeycomb. Performance measurements were made during clear weather to determine the quasi-steady state efficiency characteristic and time constant of the experimental collector with slot honeycomb protection. The least squares efficiency characteristic for both honeycomb geometries was about the same, eta = 0.810-0.450(T/sub f,i/-T/sub e//G/sub s/) which is a considerable improvement over commercial double glazed, non-selective black and single glazed, spectrally selective chrome black collectors tested in the same facility. Collector performance under both steady state and transient conditions was predicted using a lumped-parameter, conductance-capacitance thermal network model, constructed in the SINDA thermal analyzer computer program format. The measured and predicted performances are in excellent agreement.
- Research Organization:
- California Univ., Los Angeles (USA). School of Engineering and Applied Science
- DOE Contract Number:
- FG03-76CS31084
- OSTI ID:
- 6944503
- Report Number(s):
- UCLA-ENG-7846
- Resource Relation:
- Other Information: Thesis
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
FLAT PLATE COLLECTORS
HONEYCOMB STRUCTURES
PERFORMANCE
COMPUTER CALCULATIONS
EQUIVALENT CIRCUITS
HEAT LOSSES
MATHEMATICAL MODELS
NATURAL CONVECTION
NETWORK ANALYSIS
PERFORMANCE TESTING
RADIANT HEAT TRANSFER
SHEETS
CONVECTION
ELECTRONIC CIRCUITS
ENERGY LOSSES
ENERGY TRANSFER
EQUIPMENT
HEAT TRANSFER
LOSSES
MECHANICAL STRUCTURES
SOLAR COLLECTORS
SOLAR EQUIPMENT
TESTING
141000* - Solar Collectors & Concentrators