Search for dissertations about: "dryout"

Showing result 6 - 10 of 15 swedish dissertations containing the word dryout.

  2. 6. Experimental and theoretical study of post-dryout heat transfer in annuli with flow obstacle

    Author : Ionut Anghel; Henryk Anglart; Dariusz Mikielewicz; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; annulus; flow obstacles; critical heat flux; post-dryout; thermal margins; boiling water reactor; Fysik; Physics;

    Abstract : An experimental study on post dryout heat transfer regime in annuli with flow obstacles wasconducted in the High-pressure Water Test (HWAT) loop at the Royal Institute of Technologyin Stockholm, Sweden. An annulus with flow obstacles, consisting of two concentric heatedpipes (12.7x24. READ MORE

  4. 7. Mechanistic Modeling of Annular Flows at Near-Dryout Conditions

    Author : Wenyuan Fan; Henryk Anglart; Martin Rohde; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Kärnenergiteknik; Nuclear Engineering;

    Abstract : This work aims at advancing the modeling methodology for near-dryout annular flows using two different computational fluid dynamics (CFD) approaches. One is termed as the transported film approach, where the film flow is separately modeled by a simplified liquid film model and then coupled with the gas core simulation using various closures. READ MORE

  5. 8. Flow boiling of ammonia and propane in mini channels

    Author : Muhammad Hamayun Maqbool; Björn Palm; Rahmatollah Khodabandeh; Satish Kandlikar; KTH; []
    Keywords : Flow Boiling; Mini channels; Global Warming Potential; Ammonia; Propane; R134a; HFC; Two-phase; Heat Transfer; Pressure Drop; Dry out.;

    Abstract : The environmental concerns in recent times have grown especially after signing Montreal protocol. In the last ten years, researchers have focussed mainly on understanding the boiling and condensation phenomena of HFC refrigerants in minichannels. READ MORE

  6. 9. Numerical Investigations on Debris Bed Coolability and Mitigation Measures in Nordic Boiling Water Reactors

    Author : Zheng Huang; Weimin Ma; Florian Fichot; KTH; []
    Keywords : Severe accident; Debris bed; Coolability; Quench; Oxidation; MEWA code; Coupled analysis; Svåra haverier; Grusbädd; Kylbarhet; Kylning; Oxidering; MEWA program; Kopplad analys; Physics; Fysik;

    Abstract : This thesis is aiming at coolability assessment of particulate debris beds formed in hypothetical severe accidents of Nordic boiling water reactors (BWRs) which may employ either lower drywell flooding or control rod guide tubes (CRGT) cooling as severe accident management strategies. For this purpose, quench and cooling limit (dryout) of debris beds after their formation from fuel coolant interactions were investigated by numerical simulations using the MEWA code. READ MORE

  7. 10. Phase Change Phenomena During Fluid Flow in Microchannels

    Author : Rashid Ali; Björn E Palm; Gian Piero Celata; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Microchannels; Boiling; Heat Transfer; Thermal energy engineering; Termisk energiteknik; SRA - Energy; SRA - Energi;

    Abstract : Phase change phenomena of a fluid flowing in a micro channel may be exploited to make the heat exchangers more compact and energy efficient. Compact heat exchangers offer several advantages such as light weight, low cost, energy efficiency, capability of removing high heat fluxes and charge reduction are a few to mention. READ MORE