Vývoj modelu kalcinace pro ANSYS Fluent
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B
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Vysoké učení technické v Brně. Fakulta strojního inženýrství
Abstract
Cieľom diplomovej práce bolo vytvoriť model dekarbonizácie vápenca, implementovať ho do CFD nástroja ANSYS Fluent a otestovať na modeli skutočného reaktoru. Žiadaný model vychádzal z predpokladov pre Shrinking Core Model (SCM). Dielčím cieľom práce bolo spísať rešerš z oblasti nekatalytickej premeny látok a rešerš najpoužívanejších matematických modelov pre kalcináciu. Bol použitý výpočet v CFD, vykonaná citlivostná analýza a parametrická štúdia vo Fluente. Za vstupné veličiny boli zvolené údaje o zložení prúdu plynu, teplote, tlaku a hmotnostnom prietoku častíc vápenca. Najprv bol použitý časticový model s názvom Multiple Surface Reactions (MSR), ktorý je štandardnou súčasťou Fluentu. Následne bola napísaná vlastná UDF v programovacom jazyku C, ktorá vychádzala z predpokladov SCM. Výsledky z CFD výpočtu boli porovnané s experimentálnymi hodnotami z dizertačnej práce. Bolo zistené, že MSR je dostatočne presný pre potreby výpočtu, ale zanedbáva vnútro časticovú difúziu CO2 naprieč vrstvou CaO, ktorá pri kalcinácii vzniká za čelom reakcie. S použitím vytvorenej UDF je možné riešiť prúdenie s prebiehajúcou kalcináciou bez nutnosti poznania parametrov Arrheniovej rovnice. Vytvorená UDF zároveň berie do úvahy vplyv vnútro časticovej difúzie CO2 na rýchlosť reakcie.
The aim of the diploma thesis was creating a decarbonisation model of lime, implementation the model into CFD tool ANSYS Fluent and to test the decarbonisation model in a model of a real reactor. The required model was based on assumptions for a Shrinking Core Model (SCM). The main objective of this work was the non-catalytic conversion of substances and the search for the most used mathematical models for calcination. The CFD calculation, the sensitivity analysis and the Fluente parametric study were used. Data on the composition of gas flow, temperature, pressure and mass flow of limestone particles were selected for input variables. The particle model called Multiple Surface Reactions (MSR), which is a standard part of Fluent, was used at first. Subsequently, a UDF which was based on the SCM assumptions was written in the programming language C. The results of the CFD calculation were compared with the experimental values from the dissertation. It has been found that the MSR is sufficiently precise for calculation purposes but neglects the internal diffusion of CO2 through the CaO layer which forms behind the reaction front during calcination. It was found that it is possible to solve the flow with ongoing calcination without the need to know the parameters of the Arrhenian equation if the UDF is used. The created UDF incorporates the influence of intraparticular CO2 diffusion on the overall reaction rate.
The aim of the diploma thesis was creating a decarbonisation model of lime, implementation the model into CFD tool ANSYS Fluent and to test the decarbonisation model in a model of a real reactor. The required model was based on assumptions for a Shrinking Core Model (SCM). The main objective of this work was the non-catalytic conversion of substances and the search for the most used mathematical models for calcination. The CFD calculation, the sensitivity analysis and the Fluente parametric study were used. Data on the composition of gas flow, temperature, pressure and mass flow of limestone particles were selected for input variables. The particle model called Multiple Surface Reactions (MSR), which is a standard part of Fluent, was used at first. Subsequently, a UDF which was based on the SCM assumptions was written in the programming language C. The results of the CFD calculation were compared with the experimental values from the dissertation. It has been found that the MSR is sufficiently precise for calculation purposes but neglects the internal diffusion of CO2 through the CaO layer which forms behind the reaction front during calcination. It was found that it is possible to solve the flow with ongoing calcination without the need to know the parameters of the Arrhenian equation if the UDF is used. The created UDF incorporates the influence of intraparticular CO2 diffusion on the overall reaction rate.
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Citation
ANDERLE, M. Vývoj modelu kalcinace pro ANSYS Fluent [online]. Brno: Vysoké učení technické v Brně. Fakulta strojního inženýrství. 2017.
Document type
Document version
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Language of document
cs
Study field
Procesní inženýrství
Comittee
doc. Ing. Jaroslav Jícha, CSc. (předseda)
doc. Ing. Ladislav Bébar, CSc. (místopředseda)
doc. Ing. Jiří Hájek, Ph.D. (člen)
prof. Ing. Petr Stehlík, CSc., dr. h. c. (člen)
doc. Ing. Zdeněk Jegla, Ph.D. (člen)
doc. Ing. Vítězslav Máša, Ph.D. (člen)
Date of acceptance
2017-10-23
Defence
Otázka oponenta:
Vysvětlení UDF. Diplomant zodpovězen úplně a vysvětlil fázové rozhraní.
Otázky k diplomové práci:
Proč jste uvedl dané modely CFD v práci? Zodpovězeno: Popis jednotlivých modelů
Jak model dokáže snížit emise CO2? Zodpovězeno: Snížením spotřeby paliva.
Jde model implementovat do eulerovské fázi? Zodpovězeno: Problém s definicí vstupních informací, doplněno oponentem práce.
Jaká je hodnota Arrheniovy rovnice? Zodpovězeno: úplně
Result of defence
práce byla úspěšně obhájena
Document licence
Standardní licenční smlouva - přístup k plnému textu bez omezení