Sökning: "Transient boiling"

Visar resultat 1 - 5 av 15 avhandlingar innehållade orden Transient boiling.

  1. 1. Effective Spatial Mapping for Coupled Code Analysis of Thermal–Hydraulics/Neutron–Kinetics of Boiling Water Reactors

    Författare :Joanna Peltonen; Weimin Ma; Maria Avramova; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Boiling Water Reactor; RELAP5; TRACE; PARCS; Coupled TH NK analysis; Spatial Mapping; Turbine Trip; Feedwater Transient; Control Rod Drop; Reactor Stability; Hierarchical Clustering; kokvattenreaktor; reaktoranalys; RELAP5; TRACE; PARCS; TH NK analys; turbin tripp; matarvatten transient; fallande styrstav; reaktor stabilitet; hierarkisk klustringsmetodik; SRA - Energy; SRA - Energi;

    Sammanfattning : Analyses of nuclear reactor safety have increasingly required coupling of full three dimensional neutron kinetics (NK) core models with system transient thermal–hydraulics (TH) codes.  In order to produce results within a reasonable computing time, the coupled codes use two different spatial description of the reactor core. LÄS MER

  2. 2. Experimental and Numerical Investigation of the Quenching Process on Rotary Hollow Cylinder by Multiple Impinging Jets

    Författare :Mohammad Jahedi; Bahram Moshfegh; Fredrik Berntsson; Joakim Wren; Rahmatollah Khodabandeh; Högskolan i Gävle; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Multiple jet arrays; Transient boiling; Moving surface; Rotating surface; Inverse heat conduction problem; Quenching; Water impinging jet; Experimental study; Matriser av jetstrålar; Direktverkande jetstrålar; Transient kokning; Roterande yta; Icke-stationär invers värmeledning; Släckning; Experimentell studie; Intelligent industri; Intelligent Industry;

    Sammanfattning : The worldwide competitive market on metal products with higher quality in industry has increased the need to implement more advanced and controllable quenching techniques in the hardening stage of the heat treatment process. Moreover, sustainability and energy efficiency are key factors to consider in the development of advanced quenching techniques. LÄS MER

  3. 3. Interaction mechanisms for a laser-induced metallic boiling front

    Författare :Ramiz Saeed Matti Samarjy; Alexander F.H. Kaplan; Torbjörn Ilar; Michael Schmidt; Luleå tekniska universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Laser remote fusion cutting; Boiling front; High speed imaging; Additive manufacturing; Ejection; Absorption; Wavy surface; Deposition; Manufacturing Systems Engineering; Produktionsutveckling;

    Sammanfattning : This thesis is about fundamental interaction mechanisms of laser remote fusion cutting, RFC, which is based on the formation of a quasi-stationary laser-induced boiling front that causes drop ejection, preferably downwards. Laser cutting of metals, invented in 1967, has developed from a niche to a well established high quality cutting technique in the manufacturing industry. LÄS MER

  4. 4. Pool Boiling on Structured Surfaces: Heat Transfer and Critical Heat Flux : Experiments and Mechanistic Modelling

    Författare :Zhen Cao; NanoLund; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; pool boiling; heat transfer; critical heat flux; bubble dynamics; surface modification;

    Sammanfattning : In this thesis, pool boiling heat transfer was experimentally studied on structured surfaces with dielectric liquids (HFE-7200, NOVEC-649, FC-72), organic liquids (Acetone, Pentane) and deionized water.In the first step, nanoparticle coatings on copper surfaces were prepared by an electrophoretic deposition method, with Cu-Zn nanoparticles (100 nm) and Cu nanoparticles (150 nm). LÄS MER

  5. 5. Energy Efficiency Improvements in Household Refrigeration Cooling Systems

    Författare :Erik Björk; Björn Palm; Claudio Melo; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Household refrigerator; Domestic refrigerator; Free convection; Plate evaporator; Heat transfer; Flow boiling; Isobutane; R600a; Pressure drop; Two-phase; Cooling system; Charge inventory; Cyclic losses; Thermography;

    Sammanfattning : This thesis is based on eight articles all related to the characteristics of the cooling system and plate evaporator of a household refrigerator. Through these articles, knowledge is provided that can be used to increase the operational efficiency in household refrigeration. LÄS MER