Sökning: "water return temperature"

Visar resultat 1 - 5 av 18 avhandlingar innehållade orden water return temperature.

1. 1. Low-temperature District Heating : Various Aspects of Fourth-generation Systems

   Författare :Helge Averfalk; Sven Werner; Brian Elmegaard; Högskolan i Halmstad; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; District heating; low temperature; three-pipe systems; 4GDH-3P; District heating; low temperature; three-pipe systems; 4GDH-3P;

   Sammanfattning : With decreasing heat demand and less availability of high-temperature heat supply in future energy systems, the current district heating systems may experience increased competition on the heat market. A viable option to mitigate increasing competition is to operate systems with lower temperature levels, and the most conceivable way to achieve lower temperature levels is to decrease return temperatures. LÄS MER

3. 2. A numerical investigation of energy conversions in geophysical boundary layers

   Författare :Patrik Andreasson; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Vattenteknik; Water Resources Engineering;

   Sammanfattning : The detailed energy conversions in turbulent geophysical boundary layers are examined and quantified. The governing transport equations are solved by utilizing turbulence modelling. Different turbulence closures have been adopted for the boundary layers examined. LÄS MER

4. 3. Hydronic Heating Systems The Effect of Design on System Sensitivity

   Författare :Anders Trüschel; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; shunt group; controllability; district heating; room temperature; air heater; heating coil; thermal power output; deviations; water return temperature; valve group; hydronic heating; radiator system; P-band;

   Sammanfattning : This thesis starts from the recognition that a hydronic heating system can be optimised, but can never be totally perfect. Sooner or later, in practice, deviations - caused by one or more components having slightly different characteristics or settings than they are assumed or supposed to have - arise. LÄS MER

5. 4. Microsystems Technology for Underwater Vehicle Applications

   Författare :Jonas Jonsson; Greger Thornell; Hugo Nguyen; Johan Köhler; Uppsala universitet; []
   Nyckelord :Aquatic; Submersible; Underwater; Micro; Miniaturized; Sonar; Sidescan; Topography; Laser; Diffractive; Optics; Sampler; Particle; Microorganism; Acoustic; Enriching; Conductivity; Temperature; Depth; CTD; Flow; Teknisk fysik med inriktning mot mikrosystemteknik; Engineering Science with specialization in Microsystems Technology;

   Sammanfattning : The aim of this thesis work has been to investigate how miniaturization, such as microsystems technology, can potentially increase the scientific throughput in exploration of hard-to-reach underwater environments, such as the subglacial lakes of Antarctica, or other challenging environments, including cave systems and wrecks. A number of instruments and subsystems applicable to miniature submersibles have been developed and studied, and their potential to provide a high functionality density for size-restricted exploration platforms has been assessed. LÄS MER

7. 5. Low-Temperature Heating and Ventilation for Sustainability in Energy Efficient Buildings

   Författare :Arefeh Hesaraki; Sture Holmberg; Bahram Moshfegh; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Low-temperature heating system; Energy savings; Seasonal thermal energy storage; Variable air volume ventilation system; Indoor air quality;

   Sammanfattning : In 2013, the building sector consumed approximately 39 % of the total final energy use in Sweden. Energy used for heating and hot water was responsible for approximately 60 % of the total energy consumption in the building sector. Therefore, energy-efficient and renewable-based heating and ventilation systems have high potential for energy savings. LÄS MER