Sökning: "heat convection"

Visar resultat 21 - 25 av 109 avhandlingar innehållade orden heat convection.

  1. 21. Technical solutions for low-temperature heat emission in buildings

    Författare :Adnan Ploskic; Sture Holmberg; Bjarne Olesen; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Analytical and numerical modeling; baseboard skirting heating; building energy performance; computational fluid dynamics CFD ; heat transfer; low-temperature heating; space heating; thermal comfort; Järnvägsgruppen - Effektiva tågsystem för godstrafik; Järnvägsgruppen - Effektiva tågsystem för godstrafik;

    Sammanfattning : The European Union is planning to greatly decrease energy consumption during the coming decades. The ultimate goal is to create sustainable communities that are energy neutral. One way of achieving this challenging goal may be to use efficient hydronic (water-based) heating systems supported by heat pumps. LÄS MER

  3. 22. Short term water heat storage : studies of velocity and temperature fields and their importance for sizing of the storage

    Författare :Jan Dahl; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Energy Engineering; Energiteknik;

    Sammanfattning : Short term water heat storage's have been introduced in many district heating systems. The main reason for this is the possibilities opened by the storage for optimization of the generation of heat and electricity in combined heat and power plants. LÄS MER

  4. 23. A study of heat transfer from cylinders in turbulent flows by using thermochromic liquid crystals

    Författare :Roland Wiberg; KTH; []
    Nyckelord :Fluid mechanics; convection heat transfer;

    Sammanfattning : In gas quenching, metal parts are rapidly cooled from hightemperatures, and the convection heat transfer coefficientdistributions are of importance for the hardness and thedistortion (the shape nonuniformities) of the quenched parts.Thermochromic liquid crystals (TLC) and a thin foil techniques,were investi- gated and used for studies of a circular cylinderin axial flows, affected and not affected by upstream owmodifying inserts. LÄS MER

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

    Författare :Erik Björk; Björn Palm; Claudio Melo; KTH; []
    Nyckelord :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

  7. 25. Estimating the Air-Water Gas Transfer Velocity during Low Wind Conditions

    Författare :Sam Fredriksson; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Air.sea gas exchange; Turbulence; Heat flux; Natural convection; Shear; Direct numerical simulations; Gas transfer velocity; IR; Flux-chambers;

    Sammanfattning : The abundances of atmospheric carbon dioxide, CO2, and methane, CH4, are increasing. These increases affect e.g., the global carbon cycle and the climate both regionally and globally. LÄS MER