An artificial intelligence approach for biomass devolatilisation in an industrial CFD model with advanced turbulence-chemistry interaction

Du Toit, Philip C. (2018-03)

Thesis (PhD)--Stellenbosch University, 2018.

Thesis

ENGLISH SUMMARY: The ground work to include more detailed chemistry than global approaches in a combustion simulation was completed. A reduced-order model of the Biomass Chemical Percolation Devolatilisation model, ANN-Bio-CPD, was developed and implemented with artifcial neural networks in order to achieve ease of execution and computational cost reduction with regard to an industrial computational fluids dynamics application. ANN-Bio-CPD was validated with wire-mesh reactor and drop-tube furnace experiments from literature. Subsequently, the Eddy Dissipation Concept (EDC) turbulence-chemistry interaction model was implemented and validated with ANN-Bio-CPD in a bagasse- fired boiler simulation. The EDC model constants were adjusted to achieve the correct temperature and intermediate species results in combination with a two-step global reaction mechanism.

AFRIKAANSE OPSOMMING: 'n Kunsmatige intelligensiebenadering vir biomassa-devolatilisering in 'n industriële CFD-model met gevorderde turbulensie-chemie-interaksie. Die basis om meer gedetailleerde chemie as globale benaderings in 'n verbrandingsimulasie in te sluit, is voltooi. 'n Verminderde-orde model van die Biomassa Chemiese Perkolasie Devolatilisering model, ANN-Bio-CPD, is ontwikkel en met kunsmatige neurale netwerke geïmplementeer om uitvoering te vergemaklik en berekeningskostes te verminder rakende die toepassing van numeriese vloeidinamika op 'n industriële skaal. ANN-Bio-CPD is gevalideer met die eksperimente van draad-maas reaktors- en valbuis-oonde uit die literatuur. Vervolgens is die "Eddy Dissipation Concept"(EDC) turbulensie-chemie interaksie model geïmplementeer en gevalideer met ANN-Bio-CPD in 'n bagasse-gestookte ketelsimulasie. Die EDCmodelkonstantes is aangepas om die korrekte temperatuur en intermediêre spesies resultate te bereik in kombinasie met 'n tweestap globale reaksie meganisme.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/103817
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