|Tipo di tesi||Tesi di dottorato di ricerca|
|Titolo||Sviluppo di un approccio numerico per l’analisi dell’efficienza energetica di un forno per ceramica in condizioni reali di funzionamento|
|Titolo in inglese||Development of a numerical approach for the energy efficiency analysis of a ceramic kiln under actual operating conditions|
|Settore scientifico disciplinare||ING-IND/08 - MACCHINE A FLUIDO|
|Corso di studi||INGEGNERIA DELL'INNOVAZIONE INDUSTRIALE|
|Data inizio appello||2017-05-17|
|Disponibilità||Accessibile via web (tutti i file della tesi sono accessibili)|
L’utilizzo di combustibili fossili è ancora al giorno d’oggi indispensabile per le attività industriali; rispetto a 40 anni fa il consumo mondiale di energia è raddoppiato ed è evidente che assumeranno un rilievo sempre maggiore le problematiche relative alla disponibilità delle risorse energetiche di origine fossile (petrolio e gas) e all'aumento delle emissioni dovuto al loro utilizzo.
The reduction of the fossil fuel consumption and the improvement of the energy efficiency of the big industrial plants are considered the key points for limiting the human impact on the climate change. The use of fossil fuels is still nowadays unavoidable for industrial activities; compared to 40 years ago, the world energy consumption has doubled and it is clear that they will assume an increasing important role in the availability of energy resources of fossil fuels (oil and gas) and the emissions increase. An important contribution that research can offer is the implementation of specific tools and methodologies for the development of new components that could improve the performance of the production facilities and decrease their energy demand. This thesis focuses on a new numerical approach for the optimization of a ceramic kiln. In the ceramic industry, the kiln is the system with the largest energy demand, therefore its improvement can lead to a substantial reduction of the fossil fuel consumption and consequently the reduction of the CO2 emissions. The selection of the energy source, the firing technique and heat recovery system are decisive parameters for the kiln design. The numerical simulation of the whole system by means of a lumped e distributed parameter numerical approach can be adopted to evaluate both the themal-fluidinamics and the control strategy of the entire ceramic kiln, as well as to predict the contribution of each subsystem. The kiln has been analyzed under actual operating conditions and both the chambers’ temperature and the fuel consumption are predicted and a specific numerical model has been proposed to simulate the ceramic tile thermal behavior. The capability of prediction the tile temperature is paramount for addressing the product final quality. In order to address the numerical model accuracy, the calculated results have been compared with the experimental data collected on a real kiln in the production phase. In order to estimate the heat transfer coefficient relating the ceramic tile, the kiln walls and the burner flame, a detailed CFD analysis of different kiln modules has been carried out. The CFD results in terms of velocity and temperature are used in the lumped e distributed parameter model in order to determine the exchange coefficient in each surfaces. An important element in the CFD analysis is adoption of the combustion model for investigating the flame behavior in the kiln chamber and the influence on the thermal exchange. The good agreement between calculations and measurements proves that the lumped and distributed parameter approach is an efficient tool for evaluating the different kiln solutions at the design stage, in addition it is possible to simulate also different operating conditions and determined the configurations that enable a reduction of fossil fuel demand, a lower pollutant emission and a better quality of the final product. In particular, a new type of burner is investigated that is characterized by an energy recovery system from the kiln hot air flow in order to pre-heat the combustion air. The employment of the numerical simulation enables also to deepen the knowledge of the thermal exchange inside of the ceramic kiln, as well as, to evaluate an alternative type of burner for the reduction of the fossil fuel demand of approximately 10%. Finally, a flexible methodology for the efficient and accurate design phase of large industrial facilities has been defined and can be applied to any type of kiln.