Active heat capacity : models and parameters for the thermal performance of buildings
(1981)- Abstract
- The thesis concerns the characterization and evaluation of nonsteady
heat transfer in building components and building enclosures.
The major aim of the underlaying research has been to
assemble and develop simplified calculation procedures for this
purpose. To establish a simple model for heat balance calculations
three main items are treated: simplification of the heat
transfer operators, the description of the solar gain through
windows and reduction of the number of transfer paths. For nonsteady
heat conduction in opaque construction solutions are
given in the frequency domain and by finite differences.
Based on the frequency response... (More) - The thesis concerns the characterization and evaluation of nonsteady
heat transfer in building components and building enclosures.
The major aim of the underlaying research has been to
assemble and develop simplified calculation procedures for this
purpose. To establish a simple model for heat balance calculations
three main items are treated: simplification of the heat
transfer operators, the description of the solar gain through
windows and reduction of the number of transfer paths. For nonsteady
heat conduction in opaque construction solutions are
given in the frequency domain and by finite differences.
Based on the frequency response different types of RC-models are
derived. The simplest network is a single capacitance giving the
same ratio between the amplitudes of heat flow and temperature
as the real surface. This quantity is called the active heat
capacity of the wall. To estimate this quantity a simplified
calculation procedure is given. For the combination of surfaces
with different active heat capacities addition rules are established
that take into account the limited mutual radiation exchange
between the surfaces. In that way the room is transformed
into a model with two nodes, one representing the surface temperature
and one representing the room air. A solution in the time
domain allows the thermal loads to be represented as time series
and the mode of operation can be freely defined and varied during
the calculated period. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/8056125
- author
- Jóhannesson, Gudni
- supervisor
- opponent
-
- unknown], [unknown
- publishing date
- 1981
- type
- Thesis
- publication status
- published
- subject
- keywords
- Time domain solutions, RC-models, Admittance, Frequency response, Simplified models, Non-steady state, Building heat transfer, värmeflöden, transienta förlopp, byggnader, beräkningsmodeller
- pages
- 165 pages
- publisher
- Byggnadsfysik LTH, Lunds Tekniska Högskola
- defense location
- Sektionen för väg- och vattenbyggnad, John Ericssons väg 1, Hörsal V:A, Tekniska fakulteten vid Lunds universitet
- defense date
- 1981-06-02 09:15:00
- external identifiers
-
- other:TVBH-1003
- language
- English
- LU publication?
- no
- id
- ab42594f-90c3-4d3e-a659-3b840e5ac448 (old id 8056125)
- alternative location
- http://www.byfy.lth.se/fileadmin/byfy/files/TVBH-1000pdf/TVBH-1003GJ.pdf
- date added to LUP
- 2016-04-01 15:33:28
- date last changed
- 2018-11-21 20:35:06
@phdthesis{ab42594f-90c3-4d3e-a659-3b840e5ac448,
abstract = {{The thesis concerns the characterization and evaluation of nonsteady<br/><br>
heat transfer in building components and building enclosures.<br/><br>
The major aim of the underlaying research has been to<br/><br>
assemble and develop simplified calculation procedures for this<br/><br>
purpose. To establish a simple model for heat balance calculations<br/><br>
three main items are treated: simplification of the heat<br/><br>
transfer operators, the description of the solar gain through<br/><br>
windows and reduction of the number of transfer paths. For nonsteady<br/><br>
heat conduction in opaque construction solutions are<br/><br>
given in the frequency domain and by finite differences.<br/><br>
<br/><br>
Based on the frequency response different types of RC-models are<br/><br>
derived. The simplest network is a single capacitance giving the<br/><br>
same ratio between the amplitudes of heat flow and temperature<br/><br>
as the real surface. This quantity is called the active heat<br/><br>
capacity of the wall. To estimate this quantity a simplified<br/><br>
calculation procedure is given. For the combination of surfaces<br/><br>
with different active heat capacities addition rules are established<br/><br>
that take into account the limited mutual radiation exchange<br/><br>
between the surfaces. In that way the room is transformed<br/><br>
into a model with two nodes, one representing the surface temperature<br/><br>
and one representing the room air. A solution in the time<br/><br>
domain allows the thermal loads to be represented as time series<br/><br>
and the mode of operation can be freely defined and varied during<br/><br>
the calculated period.}},
author = {{Jóhannesson, Gudni}},
keywords = {{Time domain solutions; RC-models; Admittance; Frequency response; Simplified models; Non-steady state; Building heat transfer; värmeflöden; transienta förlopp; byggnader; beräkningsmodeller}},
language = {{eng}},
publisher = {{Byggnadsfysik LTH, Lunds Tekniska Högskola}},
title = {{Active heat capacity : models and parameters for the thermal performance of buildings}},
url = {{https://lup.lub.lu.se/search/files/4419706/8056200.pdf}},
year = {{1981}},
}