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Thermal bridges
are those parts or components of a
physical structure that have better
thermal conductance than their
environment i.e. than that of the
structure whose parts they are. Thermal
bridges cause excess heat loss. One can
find thermal bridges in the envelope,
refractory of energy generation/conversion
equipment, in building structures and
other mechanical systems that are
involved in heat transfer [2].
Theoretical analysis of thermal bridges
are well supplemented by the results of
infrared thermogrammetry (IR-TGM) that
help in finding their location,
identifying the boundary conditions and
verifying theoretical conclusions.
In determining the temperature
distribution along and across the thermal
bridges, the method of electric and other
modelling is often used besides
theoretical solution of the temperature-potential
field. However, the partial solution
requires accurate information on the
boundary conditions of heat transfer that
can usually be identified by measurements.
This is where IR-TGM is of particular
importance as this method, besides
locating the thermal bridges can measure
the temperature distribution of boundary
surfaces [4,6,7].
The paper presents examples for the
analysis of thermal bridges in energy
conversion/transportation equipment and
building structures. The examples feature
the identification of thermal bridge
locations and the excess heat loss.
References
[1]
Benko, I., "Applications of
infrared thermogrammetry in
thermal engineering" QIRT
92 - Eurotherm Series 27,
pp. 343-349, Paris, 1992.
[2] Benko, I.,
"Histographic analysis of
infrared thermograms in the field
of engineering" Workshop '93
on Advanced Infrared Technology
and Applications. IROE-CNR, p.33,
Capri, 1993.
[3] Benko, I.,
"Thermal detection of
buildings and environment by
INFRAMETRICS devices",
Energy and the Environment.
Proceedings of the Second Trabzon
International Energy and
Environment Symposium. Edited by
I. Dincer and T.Ayhan, pp. 205-208
Begell House, Inc. New York, 1999.
[4] Benko, I.,
"Infra-red image filtering
as a tool of temperature-field
analysis", Proceedings of
TEMPMEKO '99. Edited by J.F.
Dubbeldam and M.J. de Groot. NMi
Van Swinden Laboratorium, , Vol.2,
pp. 657-662, Delft, 1999.
[5] Benko, I.,
"Analysis of infrared
thermograms through mathematical
filtering", Gépészet 2000,
Proceedings of Second Conference
on Mechanical Engineering, edited
by K.Molnár, Gy. Ziaja, G. Vörös,
Springer Medical Publishers, Vol.2
pp. 350-355, Budapest, 2000.
[6]
Benko, I., "Mathematical
filtering of infrared images for
integrated-circuit techniques"
The Imaging Science Journal 48,
pp.45-50, 2000.
[7]
Benko, I., "Infrared testing of
thermal performance of concrete
slab buildings", 12th
Int. Conf. on Thermal Engineering
and Thermogrammetry, Budapest,
Hungary, 2001, pp. 161-166.
Imre BENKO, Prof.
Dr., Dpt. of Energy, Budapest
Univ. of Technology and
Economics,
H-1521 Budapest, Muegyetem rkp. 3/D.
208, Hungary.
Phone and fax.: +361-310-0999, e-mail:
benko@energia.bme.hu
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