Numerical study of polymer-ablation arc with polyacrylic acid + H₂O mixture

Abstract

As described in this paper, we proposed the adoption of polyacrylic acid (PAA) with H2O, which becomes PAA + H2O mixture gel, as an ablation medium for arc quenching in a low-voltage DC circuit breaker. It is well known that H2O is a highly arc-quenching medium, but it has been difficult to use H2O in liquid phase directly as an arc-quenching medium. The arc performance of PAA + H2O mixture gel was studied using numerical and experimental approaches. Numerical thermofluid simulation was conducted to obtain the arc temperature and gas flow distribution at different H2O mixing ratios in PAA + H2O gel. To consider ablation of PAA + H2O gel, a method of alternately arranging PAA and H2O in the ablation wall was also proposed. Calculation results demonstrate that increasing the H2O mixing ratio in PAA + H2O mixture gel makes the arc narrower in the temperature and electrical conductivity distributions. The experimentally obtained results also indicate that arcs confined in PAA + H2O mixture gel with higher H2O mixture become narrower than those in PAA or other materials. Moreover, arcs confined by PAA + H2O mixture gel with higher H2O mixing ratio enhance the arc resistance rapidly. The results suggest that PAA + H2O mixture gel can have higher arc-quenching performance than pure polymers.

Atomic-scale insight into arc plasma radiation-induced gassing materials ablation: photothermal decomposition behavior

“…Second is the molecular dissociation of heat absorption effect, arc plasma from the sheath to the arc column temperature range of about 3000 K-15 000 K. The ablation vapors such as H 2 , CO, H 2 O, alkanes and alkenes dissociate rapidly into H, O and C atoms at temperatures around 3000 K. This rapid dissociation of molecules leads to energy consumption in arc plasmas, and such a rapid dissociation at lower temperatures may result in arc quenching by creating a large temperature gradient around the arc fringe [50]. Furthermore, highdensity H atoms are produced in H 2 O, H 2 and hydrocarbons at temperatures above 3000 K. This high density of H atoms leads to high thermal conductivity, resulting in high arc quenching ability [51].…”