CPFD Modeling of a Novel Internally Circulating Bubbling Fluidized Bed for Chemical Looping Combustion
Notice bibliographique
Résumé
Pressurized chemical looping combustion (PCLC) is a promising next generation carbon capture technology which operates on the fundamentals of oxyfuel combustion to concentrate carbon dioxide in the flue gas stream. Oxygen is supplied through cyclic oxidation and reduction of a solid metal oxide between an air reactor and fuel reactor to prevent the direct contact of fuel and air. CanmetENERGY-Ottawa, in collaboration with Hatch Ltd., is designing a pilot scale PCLC system which uses ilmenite as the oxygen carrier and a novel fluidized bed design called the Plug Flow Internally-recirculating Reactor (PFIR). The PFIR consists of an annular bubbling fluidized region in which particles are circulated by angle jets through two reactive zones separated by baffles. The overall objective of this thesis was to provide key design parameters and insight for the construction of the pilot facility. Experimental work was first conducted investigating the minimum fluidization velocity (Umf), gas bubble size, and tube-to-bed heat transfer coefficients of different ilmenite particle size distributions (PSDs) at varying pressures up to 2000 kPa. The data was compared to a variety of literature correlations. The Saxena & Vogel (1977) constants for the Wen-Yu type correlations (𝑅𝑒𝑚𝑓=√𝐶12+𝐶2𝐴𝑟−𝐶1) resulted in the best fit for predicting the Umf of the PSDs with Sauter mean diameters (SMD) less than 109 μm, while the Chitester et al. (1984) constants resulted in better predictions for the larger particle size distributions (SMD greater than 236 μm). Gas bubble size was found to be marginally impacted by pressure, with the Mori & Wen (1975) correlation best fitting the data. The heat transfer coefficient was found to also be marginally increased by pressure with the the Molerus et al. (1995) correlation matching the atmospheric data. A computational particle fluid dynamic (CPFD) model of the experimental unit was then created and validated using the obtained data for minimum fluidization velocity and bubble size. The accuracy of the model was found to be dependent on the particle close packing factor input variable, with a value of 0.58 resulting in the best results for each of the ilmenite PSDs modeled. Finally, a CPFD model was created for a cold flow design of the PFIR to investigate the impacts of different operating parameters on the solids circulation rate and gas infiltration rate between the two reactor zones. This model used the validated parameters of the previous CPFD model to add confidence to the results. The impacts of increasing superficial gas velocity, fluidizing gas jet velocity, bed height, and pressure were all found to increase the solids circulation rate through their respective impacts on the momentum rate of the fluidizing gas. A polynomial function was fit between these two variables resulting in a method to predict the solids circulation rate. Similarly, the rate of gas infiltration between sections was found to be dependent on the solids circulation rate, allowing for a function to be made to predict the gas infiltration at different operating conditions.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».