Relative breakdown voltage and energy deposition in the liquid and gas phase of multiphase hydrocarbon plasmas

Abstract

Pulsed electrical discharges in a gas–liquid mixture deposit energy into both phases. Here, we propose a model to simulate breakdown in multiphase based on experimental data. Furthermore, we estimated breakdown voltage in each phase and then estimated energy deposition in each phase. Discharge in pure liquid showed a highly stochastic nature, having a wide breakdown voltage distribution, while the mean value closely follows a one term power law as a function of gap spacing. When there is external gas injection to the gap, breakdown voltage increased significantly due to charge dissipation on bubble surface. This effect was simulated to predict breakdown voltage in liquid with gas injection at different rates. A multiphase system model was developed to simulate breakdown in the gas–liquid phase. The model is a superposition of power law and Meek criteria physical models for the liquid and gas phases, respectively, with empirically derived coefficients. Energy deposition into each phase was estimated by this model. The gap spacing is the primary factor determining breakdown voltage and energy distribution. In studied conditions, we were able to predict the breakdown voltage and estimate energy deposition into different phases. When the gap and flow rate vary between 2 and 10 mm and flow rate 0–1 LPM, 50%–93% of electrical energy is deposited into the liquid. This model allows for predicting breakdown voltage in a multiphase. Furthermore, it allows for control of the energy distribution among the phases in a multiphase pulsed discharge system.