Sökning: "dryout"

Visar resultat 11 - 15 av 15 avhandlingar innehållade ordet dryout.

1. 11. Particulate Debris Spreading and Coolability

   Författare :Simone Basso; Pavel Kudinov; Florian Fichot; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Self-leveling; debris bed; spreading; coolability; severe accident; probabilistic framework; Monte Carlo; uncertainty; sensitivity; Fysik; Physics;

   Sammanfattning : In Nordic design of boiling water reactors, a deep water pool under the reactor vessel is employed for the core melt fragmentation and the long term cooling of decay heated corium debris in case of a severe accident. To assess the effectiveness of such accident management strategy the Risk-Oriented Accident Analysis Methodology has been proposed. LÄS MER

3. 12. MELCOR Capability Development for Simulation of Debris Bed Coolability

   Författare :Yangli Chen; Weimin Ma; Michael Buck; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Severe accident; coolability; MELCOR; COCOMO; surrogate modeling; coupling codes; uncertainty analysis.; Kärnenergiteknik; Nuclear Engineering;

   Sammanfattning : The severe accident management (SAM) strategy for a Nordic boiling water reactor (BWR) employs cavity flooding prior to vessel failure, so that the core melt (corium) discharged from the vessel could fragment and form a particulate debris bed. The key to the success of this SAM strategy is the coolability of ex-vessel debris beds. LÄS MER

4. 13. Electrochemical properties of alternative polymer electrolytes in fuel cells

   Författare :Annika Carlson; Rakel Lindström; Göran Lindbergh; Carina Lagergren; Mohamed Mamlouk; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fuel cell; anion exchange membrane; proton exchange membrane; electrode morphology; hydrogen oxidation reaction; water transport; poly phenylene oxide ; cellulose; bränslecell; anjonledande membran; protonledande membran; elektrodstruktur; vätgasoxidation; vattentransport; poly fenylenoxid ; cellulosa; Chemical Engineering; Kemiteknik;

   Sammanfattning : Fuel cells, using hydrogen as energy carrier, allow chemically‑stored energy to be utilized for many applications, including balancing the electrical grid and the propulsion of vehicles. To make the fuel cell technology more accessible and promote a sustainable energy society, this thesis focuses on alternative polymer electrolytes, as they can potentially lead to a lower cost and a more environmentally‑friendly fuel cell. LÄS MER

5. 14. Experimental Heat Transfer, pressure drop, and Flow Visualization of R-134a in Vertical Mini/Micro Tubes

   Författare :Wahib Owhaib; Björn Palm; Tassos Karayiannis; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Minichannel; microchannel; heat transfer; pressure drop; single-phase; two-phase; flow boiling; flow visualization; dry out; bubble behavior; flow pattern.; Mechanical energy engineering; Mekanisk energiteknik;

   Sammanfattning : For the application of minichannel heat exchangers, it is necessary to have accurate design tools for predicting heat transfer and pressure drop. Until recently, this type of heat exchangers was not well studied, and in the scientific literature there were large discrepancies between results reported by different investigators. LÄS MER

7. 15. Analysis methodology for RBMK-1500 core safety and investigations on corium coolabiblty during a LWR sever accidnet

   Författare :Audrius Jasiulevicius; KTH; []
   Nyckelord :RBMK. Light water reactor. Core analysis; transient analysis; reactor dynamics;

   Sammanfattning : This thesis presents the work involving two broad aspectswithin the field of nuclear reactor analysis and safety. Theseare: - development of a fully independent reactor dynamics andsafety analysis methodology of the RBMK-1500 core transientaccidents and - experiments on the enhancement of coolabilityof a particulate bed or a melt pool due to heat removal throughthe control rod guide tubes. LÄS MER