Sökning: "Additional insulation"

Visar resultat 1 - 5 av 22 avhandlingar innehållade orden Additional insulation.

  1. 1. Building Retrofit using Vacuum Insulation Panels: Hygrothermal Performance and Durability

    Författare :Pär Johansson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; laboratory; retrofitting; interior insulation; listed building; field study; exterior wall; brick wall; numerical simulation; wooden beam ends; measurement; vacuum insulation panel; transient plane heat source; exterior insulation;

    Sammanfattning : Many old buildings have unsatisfactory thermal performance compared to the standards of today. One way to increase the thermal performance is to add thermal insulation to the building envelope. However, many old buildings are listed and considered to be valuable for historical and esthetic reasons. LÄS MER

  3. 2. Active High Voltage Insulation - A New Hybrid Insulation Concept with Dynamic and Active Features

    Författare :Jörgen Blennow; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; high voltage; surface charge; dielectric coating; charge accumulation; insulation; breakdown strength; covered electrodes; air-gap; dielectric barrier discharges;

    Sammanfattning : In this thesis, the concept of a new environmental-friendly and high-performance high voltage insulation is presented. Basically, it is an electric field steering technique where the dynamic process of charge accumulation, actively and advantageously, re-distributes the electric field within an insulation system. LÄS MER

  4. 3. Polyethylene/metal oxide nanocomposites for electrical insulation in future HVDC-cables : probing properties from nano to macro

    Författare :Love Pallon; Ulf Gedde; Mikael Hedenqvist; Richard Olsson; Alun Vaughan; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Nanocomposites; polyethylene; particle dispersion; high voltage direct current cables; HVDC; HVDC insulation; MgO; intermodulation electrostatic force microscopy; ptychography; electrical tree; Nanokompositer; polyeten; HVDC; HVDC-kabel; HVDC-isolering; MgO; elektrisk isolation; partikeldispergering; elektriska träd; Fiber- och polymervetenskap; Fibre and Polymer Science;

    Sammanfattning : Nanocomposites of polyethylene and metal oxide nanoparticles have shown to be a feasible approachto the next generation of insulation in high voltage direct current cables. In order to reach an operationvoltage of 1 MV new insulation materials with reduced conductivity and increased breakdown strengthas compared to modern low-density polyethylene (LDPE) is needed. LÄS MER

  5. 4. Characterization of Electrical Insulation Exposed to Arbitrary Voltage Waveforms

    Författare :Björn Sonerud; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; arbitrary voltage waveforms; partial discharge; diagnostics; dielectric response measurement; signal processing; electrical treeing; dielectric heating.;

    Sammanfattning : The extensive use of power electronics in power systems today gives rise to other voltage waveforms than the conventional 50/60 Hz sinusoidal and consequently other types of electric stress act on high voltage insulating materials. Previous studies has shown that Pulse Width Modulated (PWM) voltages and similar waveforms increase stress in Adjustable Speed Drives (ASD) as compared with sinusoidal waveforms and it has also been shown that partial discharge (PD) activity is intensified during PWM voltages and that rise time of square like pulses affect PD inception voltage. LÄS MER

  7. 5. Protection against cold in prehospital trauma care

    Författare :Otto Henriksson; Ulf Björnstig; Tore Vikström; Peter Naredi; Hannu Rintamäki; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Hypothermia; prehospital trauma care; emergency medical services; passive warming; thermal insulation; heat loss; body temperature regulation; kirurgi; Surgery;

    Sammanfattning : Background: Protection against cold is vitally important in prehospital trauma care to reduce heat loss and prevent body core cooling. Objectives: Evaluate the effect on cold stress and thermoregulation in volunteer subjects byutilising additional insulation on a spineboard (I). LÄS MER