| Popis: |
For improvement of arc quenching performance in vacuum circuit breakers (VCBs), it is necessary to well-understand vacuum arc phenomena. To investigate dynamic behavior of metal vapor in vacuum arcs, a novel approach of a hybrid model using moving particle semi-implicit (MPS) method and finite volume method (FVM) was developed. The developed model can calculate temporal evolutions in particle density, heavy particle temperature and ionization degree between the electrodes during vacuum arc sustaining. In present study, boundary conditions of floating shield, such as reflection ratio and velocity of heavy particles, were varied to study their influence on dynamic behavior of metallic vapor between the electrodes. Calculation results show that the heavy particle temperature reached 7000 K between the electrodes, while it reached 12000 K partly around cathode surface. Such heavy particle temperature increase is due to energy transfer by collisions with energetic electrons. The heavy particle temperature can be decreased by heat exchange between metallic vapor particles and the wall. |
