Numerical simulation of air flow and thermal effects in plasma reactors, used for sewage sludge treatment

• Κύριος συγγραφέας: Πασολάρι, Ρέντιον
• Άλλοι συγγραφείς: Παπαδόπουλος, Πολύκαρπος
• Μορφή: Thesis
• Γλώσσα: English
• Έκδοση: 2019
• Θέματα: Cold plasma; Thermal analysis; Fluid dynamic analysis; Sewage sludge; OpenFOAM; Ψυχρό πλάσμα; Θερμική ανάλυση; Ρευστοδυναμική ανάλυση; Στερεά λύματα

The aim of the present thesis is to study the fluid dynamic and the thermal effects of an Dielectric Barrier Discharge (DBD) plasma reactor which is used in order to decontaminate sewage sludge. It is an engineer’s duty to study technologies that are environmentally friendly, since such technologies can save not only Earth’s life, but also humans’ life. The decontamination of sewage sludge is such a technology due to the fact that the sludges in our country are unusable, which is a large waste, since we can exploit them in agricultural purposes. This thesis deals with the numerical analysis of the mentioned reactor, and the aims are to study the fluid dynamic characteristics of the flow and the thermal effects. First of all, we present the theory behind plasma and the way that cold plasma contribute to the treatment of contaminated soil and sewage sludge. Afterwards, a description of the DBD plasma reactor follows, i.e the apparatus that is used for the plasma generation and the decontamination of the sewage sludge. A significant part of the thesis, deals with the mesh generation. The geometry of the reactor is relatively complex, so a lot of tests were necessary for an appropriate mesh to be achieved. An appropriate mesh, is a mesh dense enough to converge to the correct solution, but without an excessive computational cost, at the same time. The next large part of the thesis has to do with the fluid dynamic and the thermal analysis of the problem. A new solver, based on OpenFOAM’s standard solvers, had to be developed for the purpose of solving the specific problem. The final section of the present thesis, considers the comparison of the numerical results with the experimental data.