Sökning: "long-term thermal performance"

Visar resultat 1 - 5 av 80 avhandlingar innehållade orden long-term thermal performance.

1. 1. Predicting the Long-Term Insulation Performance of District Heating Pipes

   Författare :Camilla Persson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; heat conduction; polyurethane foam; insulation capacity; diffusion; thermal conductivity; cyclopentane; solubility coefficient; long-term performance;

   Sammanfattning : The aim of the studies that comprise this thesis was to predict the heat loss over timefrom a range of district heating pipes insulated with closed-cells foam. The thermalconductivity of the foam changes over time when it is not diffusion-tight encapsulatedagainst the environment, as diffusion alters the cell gas composition until it reachesequilibrium with the surrounding air. LÄS MER

3. 2. Degradation mechanisms and long-term performance of PUR insulation in district heating pipes

   Författare :Alberto Vega; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; mechanical performance; thermal conductivity; District heating pipe; degradation mechanisms; long-term performance; rigid polyurethane foam;

   Sammanfattning : District heating networks are used worldwide, especially in Scandinavian countries and also in many other countries, e.g. Germany, Russia, United States, South Korea and China. From an environmental point of view, district heating networks are a good alternative to more traditional building heating systems. LÄS MER

4. 3. Long-term properties of polyethylene films : efficiency of a natural antioxidant

   Författare :Clara Strandberg; Ann-Christine Albertsson; Jukka Seppälä; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Polymer Technology; alfa-tocopherol; Polyethylene PE ; Thermal aging; Infrared Spectroscopy FT-IR ; Chemiluminescence CL ; Solid-phase microextraction SPME ; Chemistry; Kemi;

   Sammanfattning : There is a growing awareness of the risks of pollution in biological systems and one potential problem is the synthetic antioxidants, used for e.g. the stabilisation of polymeric materials. Natural antioxidants are an interesting alternative, if the high efficiency and thermal stability of the synthetic compounds can be reached. LÄS MER

5. 4. Environmental and Thermal Performance of District Heating Pipes

   Författare :Morgan Fröling; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; district heat distribution; cyclopentane; district heating pipe; long-term thermal performance; life cycle assessment; insulation; polyurethane foam; environmental performance; carbon dioxide; HFC-365mfc;

   Sammanfattning : In order to move towards a sustainable society we need to increase the efficiency of our use of available resources, not only in economic terms but also in ecological terms. District heating, the utilisation of centrally produced heat for space heating and domestic hot water generation, has the potential to contribute to the eco-efficient use of energy resources in the parts of the world where space heating is needed. LÄS MER

7. 5. Long-Term Thermal Performance of Polyurethane-Insulated District Heating Pipes

   Författare :Maria E. Olsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : The distribution of hot water in district heating pipes gives rise to energy losses. In order to minimise heat losses and maintain a high water temperature most district heating pipes produced today are insulated with rigid polyurethane foam. LÄS MER