{"?xml":{"@version":"1.0"},"edm:RDF":{"@xmlns:dc":"http://purl.org/dc/elements/1.1/","@xmlns:edm":"http://www.europeana.eu/schemas/edm/","@xmlns:wgs84_pos":"http://www.w3.org/2003/01/geo/wgs84_pos","@xmlns:foaf":"http://xmlns.com/foaf/0.1/","@xmlns:rdaGr2":"http://rdvocab.info/ElementsGr2","@xmlns:oai":"http://www.openarchives.org/OAI/2.0/","@xmlns:owl":"http://www.w3.org/2002/07/owl#","@xmlns:rdf":"http://www.w3.org/1999/02/22-rdf-syntax-ns#","@xmlns:ore":"http://www.openarchives.org/ore/terms/","@xmlns:skos":"http://www.w3.org/2004/02/skos/core#","@xmlns:dcterms":"http://purl.org/dc/terms/","edm:WebResource":[{"@rdf:about":"http://www.dlib.si/stream/URN:NBN:SI:DOC-00VVKXJ5/3270308c91ad74e218253b-43f-f2155-86-/PDF","dcterms:extent":"2426 KB"},{"@rdf:about":"http://www.dlib.si/stream/URN:NBN:SI:DOC-00VVKXJ5/86cd6963-cf23-4131-974d-2f11ed812fc0/TEXT","dcterms:extent":"228 KB"},{"@rdf:about":"http://www.dlib.si/stream/URN:NBN:SI:DOC-00VVKXJ5/a3993b99-7265-4a9d-9e0c-709bf57b325d/WEB","dcterms:extent":"0 KB"}],"edm:ProvidedCHO":{"@rdf:about":"URN:NBN:SI:DOC-00VVKXJ5","dcterms:issued":"2009","dc:contributor":["Kravanja, Zdravko","Novak-Pintarič, Zorka"],"dc:creator":"Ropotar, Marcel","dc:format":{"@xml:lang":"sl","#text":"XVIII, 111 str., 30 cm"},"dc:identifier":["COBISSID:246362112","URN:URN:NBN:SI:doc-00VVKXJ5"],"dc:language":"sl","dc:publisher":{"@xml:lang":"sl","#text":"M. Ropotar"},"dc:source":{"@xml:lang":"sl","#text":"visokošolska dela"},"dc:subject":[{"@xml:lang":"sl","#text":"cevni reaktorji"},{"@xml:lang":"sl","#text":"diferencialno-algebrski sistemi enačb"},{"@xml:lang":"sl","#text":"Disertacije"},{"@xml:lang":"sl","#text":"Kemijska procesna tehnika"},{"@xml:lang":"sl","#text":"konveksne lupine"},{"@xml:lang":"sl","#text":"MINLP"},{"@xml:lang":"sl","#text":"NLP"},{"@xml:lang":"sl","#text":"ortogonalna kolokacija"},{"@xml:lang":"sl","#text":"procesna sinteza"},{"@xml:lang":"sl","#text":"procesni sintetizer"},{"@xml:lang":"sl","#text":"šaržni reaktorji"},{"@xml:lang":"sl","#text":"transformacija spremenljivk"}],"dc:title":{"@xml:lang":"sl","#text":"Načrtovanje in sinteza kemijskih procesov z uporabo učinkovitih modelnih tehnik in rešitvenih strategij| doktorska disertacija|"},"dc:description":[{"@xml:lang":"sl","#text":"This PhD thesis deals with modelling techniques and strategies for solving synthesis problems, which give rise to complex models that are very difficult to solve, highly combinatorial, nonlinear, and/or non-convex. Therefore, more efficient strategies and methods have to be developed despite that several advanced methods, algorithms, and professional software tools already exist. In the first part of the PhD thesis, alternative convex hull formulation based on mixed-integer transformation is presented. Transformation of variables transforms zero-lower-bounded variables into nonzero-lower-bounded variables. Optimization is, thus, performed in narrowed lifted space of local variables (i.e. variables representing alternative process units). Therefore, variables with nonzero lower bounds can be used when solving mixed-integer linear (MILP) or nonlinear optimization (MINLP) problems. Using nonzero-lower-bounded variables division by zero and other mathematical singularities are avoided. Additionally, nonzero-lower-bounded variables are useful when variables cannot have non-zero values even when process unit is not selected (e.g. temperature and flow). Transformation of variables has been used for: i) transforming conventional convex hull into alternative convexhull and ii) transforming conventional OA algorithm into alternative one. Several studies were performed and three different large-scale synthesis problems were solved to compare the performance and efficiency of Big-M formulation, convex hull and alternative convex hull formulation. Preliminary results with the alternative convex hull representation indicate that the alternative convex hull representation is, in most cases, the most efficient with respect to the non-linear programming (NLP) and MILP steps. The results indicate that the selection of arbitrarily-forced values to which local variables are fixed when the corresponding alternatives are rejected is very important. An inappropriate selection of these values could severely decrease the efficiency of the MINLP search. Most likely the best and the most obvious choice for arbitrarily-forced value is lower bound. Alternative formulation and outer approximation algorithm were implemented in the process synthesizer MIPSYN and, additionally, new logical interconnection nodes have been modelled and new pre-processor for outer approximation was programmed. Longer solution times of process synthesis problems are often a result of complicated reactor models. Therefore, efficient numerical procedure for solving reactor problems with orthogonal collocation was proposed. Within the procedure, the model for dynamic optimization of a batch reactor was developed and, additionally, different schemes and strategies utilized in order to increase the model's robustness. Finally, a batch reactor model for the design under uncertainty was developed. In the case of the motivating example of a batch reactor, the most efficient model was the one with moving finite elements. This model was then used to model the train of reactor elements in the plug flow reactor, and MINLP synthesis of allyl chloride production was performed. Additionally, the economic region was obtained by the one-parametric optimization. Using the proposed alternative formulation, new strategies and robust models for optimization of reactors, solving complicated synthesis models is now possible; moreover, process synthesizer MIPSYN was efficiently upgraded to solve process synthesis and other engineering problems"},{"@xml:lang":"sl","#text":"V doktorski disertaciji obravnavamo modelne tehnike in strategije za reševanje sinteznih problemov, kjer nastanejo zapleteni modeli, ki so težko rešljivi. Modeli so kombinatorično zahtevni, nelinearni in/ali nekonveksni, zato se kljub že razvitim metodam in algoritmom pogosto pojavijo potrebe po novih, učinkovitejših strategijah in metodah. V prvem delu predstavljamo alternativno formulacijo konveksne lupine, ki temelji na mešano celoštevilski transformaciji spremenljivk. Transformacija spremenljivk transformira spremenljivke z ničelno spodnjo mejo v spremenljivke z ne-ničelno spodnjo mejo. Tako izvajamo optimiranje v ožjem preslikanem dopustnem prostoru lokalnih spremenljivk, to je spremenljivk, ki pripadajo alternativnim procesnim enotam. To nam pri reševanju mešano celoštevilskih linearnih in nelinearnih optimizacijskih primerov (MILP in MINLP) omogoča uporabo ne-ničelnih spodnjih mej. Z uporabo ne-ničelnih spodnjih mej se izognemo deljenju z nič in drugim matematičnim singularnostim. Pogosto pa so ne-ničelne spodnje meje uporabne, kadar imamo opravka s spremenljivkami, kot sta temperatura in pretok, ki morata imeti ne-ničelne vrednosti tudi kadar procesna enota ni izbrana. S transformacijo spremenljivk smo i) pretvorili konvencionalno formulacijo konveksne lupine v alternativno formulacijo in ii) konvencionalni algoritem zunanje poenostavitve spremenili v alternativni algoritem OA. Alternativno formulacijo konveksne lupine smo primerjali s formulacijo veliki-M in konvencionalno formulacijo na treh sinteznih primerih in izvedli več različnih eksperimentov. Rezultati kažejo, da je alternativna formulacija v večini primerov najbolj učinkovita glede računalniškega časa, števila iteracij in vozlišč. Ugotovili smo, da izbor vrednosti spremenljivk, ko alternativa ni izbrana, zelo vpliva na učinkovitost alternativne formulacije; in da je najprimernejša in najenostavnejša izbira kar spodnja ne-ničelna meja. Alternativno formulacijo in alternativni algoritem smo vnesliv procesni sintetizer MIPSYN in pri tem zmodelirali nove logične povezovalne člene in sprogramirali nov preprocesor za zunanje poenostavitve. Pogosto je dolg čas reševanja procesnih sinteznih problemov posledica zapletenih modelov reaktorjev. Zato smo za reaktorje, ki so opisani z diferencialnimi enačbami (šaržni, cevni) in jih rešujemo z metodo ortogonalne kolokacije končnih elementov, predlagali učinkovito numerično proceduro za reševanje. V sklopu procedure smo razvili model za dinamično optimiranje šaržnega reaktorja in preizkušali različne strategije in sheme, s katerimi smo povečevali robustnost modela. Nazadnje smo razvili še model za načrtovanje fleksibilnega šaržnega reaktorja, s katerim je mogoče tolerirati odstopanja procesnih parametrov. Pri reševanju motivacijskega primera šaržnega reaktorja se je kot najučinkovitejši izkazal model NLP s pomičnimi končnimi elementi. Ta model smo nato uporabili tudi za modeliranje niza elementov v cevnem reaktorju in izvedli sintezo MINLP študijske procesne sheme za proizvodnjo alilklorida ter z eno-parametričnim optimiranjem iz najboljših rešitev določili še ekonomsko območje. S predlagano alternativno formulacijo, novimi strategijami in robustnimi modeli za optimiranje reaktorjev je mogoče lažje reševati zapletene sintezne probleme, procesni sintetizer MIPSYN pa je tako postal še učinkovitejše programsko orodje za sintezo procesov in reševanje drugih tehniških problemov"}],"edm:type":"TEXT","dc:type":[{"@xml:lang":"sl","#text":"visokošolska dela"},{"@xml:lang":"en","#text":"theses and dissertations"},{"@rdf:resource":"http://www.wikidata.org/entity/Q1266946"}]},"ore:Aggregation":{"@rdf:about":"http://www.dlib.si/?URN=URN:NBN:SI:DOC-00VVKXJ5","edm:aggregatedCHO":{"@rdf:resource":"URN:NBN:SI:DOC-00VVKXJ5"},"edm:isShownBy":{"@rdf:resource":"http://www.dlib.si/stream/URN:NBN:SI:DOC-00VVKXJ5/3270308c91ad74e218253b-43f-f2155-86-/PDF"},"edm:rights":{"@rdf:resource":"http://rightsstatements.org/vocab/InC/1.0/"},"edm:provider":"Slovenian National E-content Aggregator","edm:intermediateProvider":{"@xml:lang":"en","#text":"National and University Library of Slovenia"},"edm:dataProvider":{"@xml:lang":"sl","#text":"Univerza v Mariboru, Fakulteta za kemijo in kemijsko tehnologijo"},"edm:object":{"@rdf:resource":"http://www.dlib.si/streamdb/URN:NBN:SI:DOC-00VVKXJ5/maxi/edm"},"edm:isShownAt":{"@rdf:resource":"http://www.dlib.si/details/URN:NBN:SI:DOC-00VVKXJ5"}}}}