Thesis-2000-Wren.pdf (25.77 MB)
Download fileComputer simulation of intelligent building facades
thesis
posted on 2010-11-25, 10:30 authored by Duncan E. WrenThe economic and environmental benefits secured through the increased integration of
photovoltaic (PV) technology into the built environment are undeniable and provide
the principal motivation for this research.
Present delays in the technology transfer of building integrated photovoltaics (BIPV)
can be attributed to the following; material cost, performance guarantee, increased installation complexity and unfamiliar technology.
It is well understood that the temperature of a PV material receiving solar irradiation,
will increase with solar intensity, while reducing in electrical efficiency. It therefore
makes economic sense to minimise the increase in PV material temperature and
maximise electrical energy yield. Through the addition of a convecting fluid, flowing over the surface of heated PV
material, heat transfer will be induced. With the added benefit of warm air capture
from an integrated photovoltaic/thermal (PVT) collector, the economic benefits are
increased. But, to ensure maximum utilisation of both thermal and electrical energy
production, a significantly more complex control system has to be employed than that
for a PV system on its own. Modelling the energy flows within a multifunctional PVT building facade presents a
problem of considerable complexity. Previous work in this area has centred on
performing finite element analysis of the system in order to find solutions to complex
algorithms. It requires considerable computational power to perform these calculations
and often the results produced are much more detailed than required.
Within this thesis, a fully operational PVT facade model is presented, giving the
potential for improved multifunctional facade design.
This new model has been developed into a software program for use within the
TRNSYS environment. By using the TRNSYS software, a detailed building model has
been created and integrated with the new PVT facade model. Simulations were then
undertaken to evaluate the energy transfers between internal and external environments
and the electrical and thermal energy capturing capabilities of the facade. Simulated
results have been evaluated against experimental data taken from a fully operational
PVT facade.
The results conclude that the presented model simulates the energy flows around,
through and within the facade (radiative, conductive, convective and electrical) very
well. Performance enhancing development work is due to take place on the operational
facade analysed in this work, very soon. This new facade model will be used as a tool
to evaluate the proposed changes to the building prior to this development work being
undertaken.
History
School
- Mechanical, Electrical and Manufacturing Engineering