Sökning: "thermal runaway"

Visar resultat 1 - 5 av 9 avhandlingar innehållade orden thermal runaway.

1. 1. Kinetic modelling of runaway in plasmas

   Författare :Ola Embréus; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fokker-Planck equation; synchrotron radiation; plasma; runaway; bremsstrahlung; Boltzmann equation;

   Sammanfattning : The phenomenon of runaway occurs in plasmas in the presence of a strong electric field, which overcomes the collisional friction acting on the charged particles moving through the plasma. A subpopulation of particles can then be accelerated to energies significantly higher than the thermal energy. LÄS MER

3. 2. Runaway electrons and Alfvén eigenmodes in tokamaks

   Författare :Håkan Smith; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; two-way diffusion equation; compressional Alfvén eigenmode; fusion plasma physics; tokamak disruption; runaway electron; Alfvén cascade;

   Sammanfattning : Runaway electrons can be generated as a consequence of the rapid thermal quench of the plasma in a tokamak disruption. If the time scale of this cooling is short compared to the collision time in the tail of the electron velocity distribution, incomplete thermalisation of this tail leads to a burst of runaway production. LÄS MER

4. 3. Assessment of safety characteristics for Li-ion battery cells by abuse testing

   Författare :Carl Fredrik Larsson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; overcharge; Lithium-ion; toxic gases; abuse test; thermal runaway; short circuit; safety; battery; fire;

   Sammanfattning : Despite the many advantages with lithium-ion batteries there can be disadvantages in form of safetyissues. In an abuse situation a Li-ion cell can undergo a thermal runaway releasing excessive heat,flammable and toxic gas emissions and eventually accompanied by dissembling/explosion and fire. LÄS MER

5. 4. Lithium-ion Battery Safety - Assessment by Abuse Testing, Fluoride Gas Emissions and Fire Propagation

   Författare :Carl Fredrik Larsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fire; thermal runaway; gas emission; gas explosion; propagation; safety; abuse testing; Lithium-ion; cell case explosion; hydrogen fluoride;

   Sammanfattning : Lithium-ion batteries offer high energy and power densities as well as long life time but have a more narrow stability window compared to other battery types and contain reactive and flammable materials. In case of overheating the battery cell can release gas (vent) and, at temperatures of about 150-200 °C, a so called thermal runaway can occur, that is a rapid self-heated temperature increase which is typically accompanied with a large release of smoke and gas, fire and a potential cell case explosion or gas explosion. LÄS MER

7. 5. Disruption Mitigation in Tokamaks with Massive Material Injection

   Författare :Oskar Vallhagen; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; shattered pellet injection; fusion plasma; disruption mitigation; runaway electron;

   Sammanfattning : The sudden loss of confinement of the energy content of fusion plasmas in off-normal events, called disruptions, is among the most severe threats to the future of fusion energy based on the tokamak design. An efficient disruption mitigation system will therefore be of utmost importance for future large, high-current devices such as ITER. LÄS MER