Effects of copper vapour on thermophysical properties of CO2-N2 plasma

Abstract

CO2-N2 mixtures are often used as arc quenching medium (to replace SF6) in circuit breakers and shielding gas in arc welding. In such applications, copper vapour resulting from electrode surfaces can modify characteristics of plasmas. This paper therefore presents an investigation of the effects of copper on thermophysical properties of CO2-N2 plasma. The equilibrium compositions, thermodynamic properties (including mass density, specific enthalpy, and specific heat), transport coefficients (including electrical conductivity, viscosity, and thermal conductivity), and four kinds of combined diffusion coefficients due to composition gradients, applied electric fields, temperature gradients, and pressure gradients respectively, were calculated and discussed for CO2-N2 (mixing ratio 7:3) plasma contaminated by different proportions of copper vapour. The significant influences of copper were observed on all the properties of CO2-N2-Cu mixtures. The better ionization ability and larger molar mass of copper and larger collision integrals related to copper, should be responsible for such influences.

Double-peak specific heat anomaly and correlations in the Bose-Hubbard model

“…Experimentally, the doublepeak anomaly is measured in magnetic pyrochlore oxides [3], the canonical spin-ice materials Dy 2 Ti 2 O 7 [4][5][6] and Tb 2 Ti 2 O 7 [7], their mixtures Dy 2−x Tb x Ti 2 O 7 [8], lead-based pyrochlores [9], and spin glasses like R 2 Mo 2 O 7 (R=Y, Sm, or Gd) [10]. Other examples include heavyfermion compounds [11,12], bosonic superfluids in spindimer networks [13], CO 2 N 2 plasma [14], lipid bilayers containing colesterol [15], as wells as mixtures of liquid crystal and nanoparticles [16]. In a theoretical framework, the anomaly was verified for spin models with antiferromagnetic Heisenberg interactions [17][18][19][20][21][22], Ising pyrochlore magnets using Monte Carlo simulations [23,24], Ising models [25][26][27][28] in distinct geometries, and quantum ferrimagnets [29].…”

State of Art and Challenges for the Calculation of Radiative and Transport Properties of Thermal Plasmas in HVCB

“…The thermodynamic properties (mass density, enthalpy, and specific heat at constant pressure) are directly deduced from the plasma compositions. Some results are given in [2][3][4][5][6][7][8][9] and behaviors are explained versus temperature, mixtures and pressure. The transport coefficients (viscosity, thermal and electrical conductivities) are obtained according to the Chapman-Enskog method and a previous calculation of collision integrals depending on the interaction potentials chosen to characterize the different collisions between particles (neutral-neutral, ion-neutral, electron-neutral and charged-charged collisions).…”

“…The transport coefficients (viscosity, thermal and electrical conductivities) are obtained according to the Chapman-Enskog method and a previous calculation of collision integrals depending on the interaction potentials chosen to characterize the different collisions between particles (neutral-neutral, ion-neutral, electron-neutral and charged-charged collisions). The study of the collision integrals constitutes the most important part of the calculation of the transport coefficients and are often responsible for the differences observed between the authors [2][3][4][5][6][7][8][9][10][11][12][13].…”

Modelling of the conductor vaporization process for single-turn coil

“…Furthermore, the physical parameters of the conductor are influenced by the phase state. The appearance of the liquid and gaseous metal not only change the thermodynamic parameters of the conductor, including thermal conductivity k, specific heat capacity C P and mass density ρ m , but also reduce the electrical conductivity σ significantly [20][21][22][23][24][25][26][27][28][29][30]. Therefore, to ensure the vaporization simulation accuracy, these variations should also be considered.…”