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The impact of optical and thermal properties on the performance of flat plate solar collectors

Hellström, Bengt LU ; Adsten, M; Nostell, P; Karlsson, Björn LU and Wackelgard, E (2003) In Renewable Energy 28(3). p.331-344
Abstract
The impact of the optical properties on the annual performance of flat plate collectors in a Swedish climate has been estimated with the MINSUN program. The collector parameters were determined with a theoretically based calculation program verified from laboratory measurements. The importance of changes in solar absorptance and thermal emittance of the absorber, the addition of a teflon film or a teflon honeycomb, antireflection treatment of the, cover glazing and combinations of these improvements were investigated. The results show that several improvements can be achieved for solar thermal absorbers. A combined increase in absorptance from 0.95 to 0.97 and a decrease in emittance from 0.10 to 0.05 increase the annual performance with... (More)
The impact of the optical properties on the annual performance of flat plate collectors in a Swedish climate has been estimated with the MINSUN program. The collector parameters were determined with a theoretically based calculation program verified from laboratory measurements. The importance of changes in solar absorptance and thermal emittance of the absorber, the addition of a teflon film or a teflon honeycomb, antireflection treatment of the, cover glazing and combinations of these improvements were investigated. The results show that several improvements can be achieved for solar thermal absorbers. A combined increase in absorptance from 0.95 to 0.97 and a decrease in emittance from 0.10 to 0.05 increase the annual performance with 6.7% at 50 degreesC operating temperature. The increase in performance by installing a teflon film as second glazing was estimated to 5.6% at 50 degreesC. If instead a teflon honeycomb is installed, a twice as high performance increase is obtained, 12.1 %. Antireflection treatment of the cover glazing increases the annual output with 6.5% at 50 degreesC. A combination of absorber improvements together with a teflon honeycomb and an antireflection treated glazing results in a total increase of 24.6% at 50 degreesC. Including external booster reflectors increases the expected annual output at 50 degreesC to 19.9-29.4% depending on reflector material. (C) 2002 Elsevier Science Ltd. All rights reserved. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
booster reflector, solar absorber, antireflection treatment, teflon, solar thermal collector, materials
in
Renewable Energy
volume
28
issue
3
pages
331 - 344
publisher
Elsevier
external identifiers
  • wos:000178596100001
  • scopus:0036489471
ISSN
0960-1481
DOI
10.1016/S0960-1481(02)00040-X
language
English
LU publication?
yes
id
df0662ff-8dc8-4ac2-8f59-af06c72d4378 (old id 325139)
date added to LUP
2007-09-13 08:09:38
date last changed
2018-07-01 03:31:42
@article{df0662ff-8dc8-4ac2-8f59-af06c72d4378,
  abstract     = {The impact of the optical properties on the annual performance of flat plate collectors in a Swedish climate has been estimated with the MINSUN program. The collector parameters were determined with a theoretically based calculation program verified from laboratory measurements. The importance of changes in solar absorptance and thermal emittance of the absorber, the addition of a teflon film or a teflon honeycomb, antireflection treatment of the, cover glazing and combinations of these improvements were investigated. The results show that several improvements can be achieved for solar thermal absorbers. A combined increase in absorptance from 0.95 to 0.97 and a decrease in emittance from 0.10 to 0.05 increase the annual performance with 6.7% at 50 degreesC operating temperature. The increase in performance by installing a teflon film as second glazing was estimated to 5.6% at 50 degreesC. If instead a teflon honeycomb is installed, a twice as high performance increase is obtained, 12.1 %. Antireflection treatment of the cover glazing increases the annual output with 6.5% at 50 degreesC. A combination of absorber improvements together with a teflon honeycomb and an antireflection treated glazing results in a total increase of 24.6% at 50 degreesC. Including external booster reflectors increases the expected annual output at 50 degreesC to 19.9-29.4% depending on reflector material. (C) 2002 Elsevier Science Ltd. All rights reserved.},
  author       = {Hellström, Bengt and Adsten, M and Nostell, P and Karlsson, Björn and Wackelgard, E},
  issn         = {0960-1481},
  keyword      = {booster reflector,solar absorber,antireflection treatment,teflon,solar thermal collector,materials},
  language     = {eng},
  number       = {3},
  pages        = {331--344},
  publisher    = {Elsevier},
  series       = {Renewable Energy},
  title        = {The impact of optical and thermal properties on the performance of flat plate solar collectors},
  url          = {http://dx.doi.org/10.1016/S0960-1481(02)00040-X},
  volume       = {28},
  year         = {2003},
}