Search for dissertations about: "insulation"

Showing result 21 - 25 of 302 swedish dissertations containing the word insulation.

2. 21. Evaluating Resistance to Corona and Ozone in Polymeric Materials for High Voltage Outdoor Applications

   Author : Bin Ma; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ozone; housing material; nano-composite; corona; Outdoor insulation; composite insulation;

   Abstract : Resistance to corona discharges and ozone, the well known ageing factors for polymeric materials used in outdoor insulation, has been listed as being of great importance among twelve properties identified by CIGRE WG D1.14 – Material Properties for Non-ceramic Outdoor Insulation. READ MORE

4. 22. Partial Discharges Studied with Variable Frequency of the Applied Voltage

   Author : Hans Edin; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; diagnostic methods; partial discharges; phase resolved; variable frequency; dielectric spectroscopy; dielectric response; harmonics; insulation; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

   Abstract : This thesis concerns partial discharge (PD) diagnostics withvariable frequency of applied voltage in the frequency range 1mHz - 400 Hz. The exploration of a new type of spectroscopythat combines partial discharge analysis and dielectricresponse is demonstrated. READ MORE

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

   Author : Morgan Fröling; Chalmers tekniska högskola; []
   Keywords : 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;

   Abstract : 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. READ MORE

6. 24. Polyethylene – metal oxide particle nanocomposites for future HVDC cable insulation : From interface tailoring to designed performance

   Author : Dongming Liu; Ulf Gedde; Mikael Hedenqvist; Richard Olsson; Linda Schadler; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; HVDC; electrical insulation; core-shell nanoparticles; surface modification; silane chemistry; nanocomposites; polyethylene; adsorption; long-term stability; interface; particle dispersion; cavitation; conductivity; HVDC; elektrisk isolation; ytmodifiering; silankemi; nanokompositer; polyeten; adsorption; långtidsstabilitet; ytskikt; partikeldispergering; kavitation; ledningsförmåga; Fiber- och polymervetenskap; Fibre and Polymer Science;

   Abstract : Low-density polyethylene (LDPE) nanocomposites containing metal oxide nanoparticles are considered as promising candidates for insulating materials in future high-voltage direct-current (HVDC) cables. The significant improvement in dielectric properties compared with unfilled polymer is attributed to the large and active interface between the nanoparticles and the polymer. READ MORE

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

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

   Abstract : 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. READ MORE