Implementation and performance analysis of a model-based controller on a batch pulp digester

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dc.contributor.advisor De Vaal, Phillip L. en
dc.contributor.postgraduate Sandrock, Carl en
dc.date.accessioned 2013-09-07T14:07:49Z
dc.date.available 2004-10-19 en
dc.date.available 2013-09-07T14:07:49Z
dc.date.created 2003-10-31 en
dc.date.issued 2005-10-19 en
dc.date.submitted 2004-10-15 en
dc.description Dissertation (MEng (Control))--University of Pretoria, 2005. en
dc.description.abstract The control of batch pulp digesters is hampered by insufficient measurements as well as nonlinearity and weak correlation between consecutive cooks. This makes a model-based approach to control attractive. Due to the age of the industry, many legacy controllers are in place on digesters around the world. The theoretical variance obtained by Monte Carlo modelling of a new controller is used as a benchmark for performance comparison between an old control system (S-factor) and a new model based controller developed by the University of Pretoria (the UP controller). This study covers the development of the controller, Monte Carlo modelling of the old and new controllers and in-situ testing of the UP controller on an operating digester. During Monte Carlo simulation, the UP controller outperformed the legacy controller, obtaining a theoretical overall variance of 3,07 (which will be used as the baseline for performance measurement) while also showing larger responses to tuning factors. The S-factor performed at 6,8 times the theoretical optimum variance during in situ testing, while the UP controller performed at 3,9 times the theoretical optimum (43% better than the S-factor controller). An average error 90% lower than that of the S-factor controller was obtained when using the UP controller. Additional benefits of the new controller include easy inclusion of new measurements and clear relations between the tuning parameters used and the conditions in the digester. en
dc.description.availability unrestricted en
dc.description.department Chemical Engineering en
dc.identifier.citation Sandrock, C 2003, Implementation and performance analysis of a model-based controller on a batch pulp digester, MEng dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://hdl.handle.net/2263/28717 > en
dc.identifier.upetdurl http://upetd.up.ac.za/thesis/available/etd-10152004-113239/ en
dc.identifier.uri http://hdl.handle.net/2263/28717
dc.language.iso en
dc.publisher University of Pretoria en_ZA
dc.rights © 2003, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. en
dc.subject Model based control en
dc.subject Monte carlo en
dc.subject Performance analysis en
dc.subject Batch control en
dc.subject Pulping en
dc.subject Sulphite process en
dc.subject UCTD en_US
dc.title Implementation and performance analysis of a model-based controller on a batch pulp digester en
dc.type Dissertation en


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