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Visar resultat 1 - 5 av 35 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Efficiency factors for space heating system in buildings

   Författare :Christian Brembilla; Thomas Olofsson; Ronny Östin; Mohsen Soleimani-Mohseni; Bjørn Reidar Sørensen; Umeå universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Efficiency factors of space heating; hydronic panel radiator; hydronic floor heating; multilayer wall; numerical modelling; room control volume; decrement factor; time delay; heat conduction; heat convection; heat radiation; heat storage; thermal inertia; Euler solver; Newton-Raphson method; synthetic weather file; feedback and feed-forward control strategies; adaptive control; validation methodology; uncertainty bands; robustness of model predictions; thermostatic booth simulator; differential sensitivity analysis; transient model of panel radiator with multiple storage elements; active thermal mass; benchmark performance indicator; linear regression model; calibration through uncertainty bands; hybrid model of low-energy building: law driven data driven; outdoor temperature compensation heating curve; solar radiation model; finite difference method; heat equation;

   Sammanfattning : The thesis focuses on the efficiency of the space heating system. In particular, the efficiency factors measure the efficiency of thermal zone. The efficiency factors measures how the energy is used in a space heating. LÄS MER

3. 2. Heat and Mass Transfer to a Single Particle in Fluidized Bed

   Författare :Gennadij I. Palconok; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; mass transfer; turbulence; circulating fluidized beds; active particle; bubbling; heat; combustion; devolatilization;

   Sammanfattning : Heat and mass transfer to/from a single active particle in bubbling and circulating fluidized beds have been studied with application to fluidized bed combustion. A method of calculation of the heat and mass transfer coefficients in a bubbling fluidized bed (BFB) has been developed. LÄS MER

4. 3. Analysis of PEM Fuel Cell Stacks and Systems with Water/Thermal Balances

   Författare :Takamasa Ito; Värmeöverföring; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Thermal engineering; applied thermodynamics; Termisk teknik; termodynamik; PEM Fuel Cell Systems ; Water Thermal Balances ; Heat Exchangers ; PEM Fuel Cell Stacks ;

   Sammanfattning : The Proton Exchange Membrane (PEM) fuel cell has been investigated for a long time, and is regarded as a new energy source for various applications, such as portable, stationary and automotive ones. However, due to the shortage of the infrastructure in the society, the high cost, the difficulty of the water/thermal management, etc. LÄS MER

5. 4. Energy Efficiency through Thermal Energy Storage : Possibilities for the Swedish Building Stock

   Författare :Johan Heier; Viktoria Martin; Chris Bales; Signhild Gehlin; Högskolan Dalarna; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; thermal energy storage; buildings; energy efficiency; energy savings; peak load reduction; Swedish building stock; termisk energilagring; byggnader; energieffektivisering; energibesparing; toppbelastningsutjämning; Sveriges byggnadsbestånd; Värmelagring i byggnader;

   Sammanfattning : The need for heating and cooling in buildings constitutes a considerable part of the total energy use in a country and reducing this need is of outmost importance in order to reach national and international goals for reducing energy use and emissions. One important way of reaching these goals is to increase the proportion of renewable energy used for heating and cooling of buildings. LÄS MER

7. 5. Multi frequency interferometer studies of active and starburst galaxies

   Författare :Evert Olsson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; galaxies: active; galaxies: ISM; galaxies: starburst; galaxies: evolution;

   Sammanfattning : We report the results of a multi-frequency study of three interactinggalaxies: NGC 5218, NGC 1614 and NGC 4194 (the Medusa merger). These sourcesbelong to different classes of active and starburst galaxies. LÄS MER