% IMPORTANT: The following is UTF-8 encoded. This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.
@PHDTHESIS{Dolls:1021855,
author = {Dolls, Sarah},
othercontributors = {Abel, Dirk and Kneer, Reinhold},
title = {{M}odellbasierte {R}egelung des {A}nfahrvorgangs eines
{O}xyfuel-{P}rozesses},
school = {Rheinisch-Westfälische Technische Hochschule Aachen},
type = {Dissertation},
address = {Aachen},
publisher = {RWTH Aachen University},
reportid = {RWTH-2025-09695},
pages = {1 Online-Ressource : Illustrationen},
year = {2025},
note = {Veröffentlicht auf dem Publikationsserver der RWTH Aachen
University; Dissertation, Rheinisch-Westfälische Technische
Hochschule Aachen, 2025},
abstract = {The present work examines the start-up process of the
membrane-based oxyfuel process proposed in the OXYCOAL-AC
project (project duration 2004 to 2011). The focus of the
work is on a model-based control approach investigated as
part of the project participation from 2007 to 2010, which
can be used to carry out the start-up process of this
process, which requires a large number of additional steps
compared to the start-up process of conventional coal-fired
power plants due to the novel process structure of the flue
gas recirculation and its enrichment with oxygen in a
membrane system. While the original research focused on the
use of oxyfuel combustion in coal-fired power plants, the
focus today is increasingly on industrial processes such as
the cement industry or waste incineration, where CO2
emissions are generated by material conversions in the
process. Building on the findings of the OXYCOAL-AC project,
general follow-up activities in the field of oxyfuel
combustion (SFB Oxyflame) and oxygen supply using membranes
(MEM-OXYCOAL and HETMOC) have taken place. The basis for the
analysis of the start-up process of the OXYCOAL-AC process
is the extension and modification of a component library so
that a detailed non-linear model of the entire process can
be created, with which the entire start-up process from
power plant shutdown to load increase to 100 $\%$ can be
simulated. To validate the component models, data from a
pilot plant of a project partner is processed and the models
are parameterised according to the plant components. The
comparison of simulation and measurement data shows that the
models can reproduce the real behaviour of the system
components well. Based on the detailed process model, a
linear, simplified process model is created for use in a
model-based predictive controller. For this purpose, the
start-up procedure of the process is simulated and the model
is linearised along the start-up curve at several transient
operating points, reduced and the individual models are
combined to form an overall process model. By using a
controller with an internal process model to regulate the
start-up process, a start-up concept is developed that can
take into account the requirements of the
temperature-critical ceramic membrane system at all times.
Based on the start-up process of a conventional coal-fired
power plant, a start-up concept is developed for the
OXYCOAL-AC process, in which the start-up process of the
flue gas cycle is integrated into the start-up process of
the boiler and supplemented by additional measures. As the
membrane system only supplies the oxygen required for
oxyfuel combustion at high temperatures, the boiler is first
started up with ambient air and the resulting flue gas is
used to heat up the recirculation circuit before a
continuous transition from air operation to oxyfuel
operation takes place. In order to achieve the desired
OXYCOAL-AC operation as quickly as possible, the maximal
allowed temperature change rate is not only maintained, but
also maxed out, during the start-up process by using
model-based predictive control. For the boiler, taking into
account the maximal allowed temperature change rate of the
membrane material results in an extension of the start-up
time to full load by about 10 percentage points compared to
the start-up process in a conventional coal-fired power
plant. The full OXYCOAL-AC operation is only reached eight
hours later.},
cin = {416610},
ddc = {620},
cid = {$I:(DE-82)416610_20140620$},
typ = {PUB:(DE-HGF)11},
doi = {10.18154/RWTH-2025-09695},
url = {https://publications.rwth-aachen.de/record/1021855},
}
guest ::