A. Fernandez-Rueda

Experimental investigation and numerical modelling of positive corona discharge: ozone generation

The spatial distribution of the species generated in a wire-cylinder positive corona discharge in pure oxygen has been computed using a plasma chemistry model that includes the most significant reactions between electrons, ions, atoms and molecules. The plasma chemistry model is included in the continuity equations of each species, which are coupled with Poissons equation for the electric field and the energy conservation equation for the gas temperature. The current–voltage characteristic measured in the experiments has been used as an input data to the numerical simulation. The numerical model is able to reproduce the basic structure of the positive corona discharge and highlights the importance of Joule heating on ozone generation. The average ozone density has been computed as a function of current intensity and compared with the experimental measurements of ozone concentration determined by UV absorption spectroscopy.

Ozone generation by negative corona discharge: the effect of Joule heating

Ozone generation in pure oxygen using a wire-to-cylinder corona discharge reactor is experimentally and numerically investigated. Ozone concentration is determined by means of direct UV spectroscopy and the effects of Joule heating and ozone decomposition on the electrodes are analysed for different discharge gaps. The numerical model combines the physical processes in the corona discharge with the chemistry of ozone formation and destruction. The chemical kinetics model and the electrical model are coupled through Poissons equation, and the current?voltage (CV) characteristic measured in experiments is used as input data to the numerical simulation. The numerical model is able to predict the radial distributions of electrons, ions, atoms and molecules for each applied voltage of the CV characteristic. In particular, the evolution of ozone density inside the discharge cell has been investigated as a function of current intensity and applied voltage.

Experimental Study of Ozone Generation by Negative Corona Discharge in Mixtures of N2 and O2

Ozone generation by negative DC corona discharge in N2-O2 mixtures has been experimentally investigated using a coaxial wire-cylinder corona reactor operating at room temperature and atmospheric pressure. The experiments have been carried out under different gas flows (15 cm3 min−1 to 200 cm3 min−1) and gas compositions (5% to 90% of O2), and the effect of these parameters on the corona current, the ozone density and the efficiency of the ozone generator have been analyzed. The global rate coefficients for ozone formation and destruction have also been evaluated, and their values compared with those reported by other authors. The maximum efficiency for ozone production was found in gas mixtures with oxygen content about 70–80%.

Ozone generation using negative wire-to-cylinder corona discharge: the influence of anode composition and radius

Ozone generation by negative corona discharge has been investigated using a coaxial wire-cylinder electrode system, and the effect of the composition of the anode (the cylinder) and its radius has been analyzed. Specifically, three different radii (0.65, 0.85 and 1.1 cm) and two different materials (stainless steel and aluminium) have been used for the anode. Ozone concentration was measured using a UV spectrophotometer, both during the electrical discharge and after its extinction. The experimental measurements are complemented with the numerical simulation of the problem using a drift-diffusion model that includes ozone decomposition on the anode and the effect of Joule heating.

Numerical simulation of wire-to-cylinder negative corona discharge in dry air

The steady radial distribution of chemical species in a negative corona discharge is predicted with the help of a physico-chemical model that includes both elementary plasma processes and chemical reactions among neutral and charged species. Corona discharge is generated in dry air using a wire-to-cylinder coaxial electrode system. The current-voltage characteristic of the corona current is used as the input data in the numerical model. The computed ozone density is compared with the experimental concentration determined by ultraviolet spectroscopy.

Experimental characterization and numerical modeling of a wire-to-cylinder corona discharge ozonizer

Ozone generation in an oxygen-fed wire-to-cylinder corona discharge ozonizer is investigated experimentally and numerically. The spatial distribution of chemical species produced in the corona discharge is obtained by means of a physico-chemical model that includes both elementary plasma processes (ionization, electron attachment and detachment, ion recombination, etc.) and chemical reactions between neutral species. The current-voltage characteristic measured in experiments is used as an input for the numerical simulation. Ozone concentration is determined by means of direct UV spectroscopy, and the effects of the gas flow rate and the anode radius are analyzed.

Corona discharge in flowing synthetic air

The formation of ozone and nitrogen oxides in synthetic air by negative DC corona discharge has been experimentally investigated. The electrical discharge was generated using a coaxial wire-cylinder corona discharge reactor, and different gas flow rates were imposed through the discharge cell. Ultraviolet absorption spectroscopy was used to identify and quantify the generation of chemical species.

Physico-chemical modeling of corona discharge in SF/sub 6/

Negative corona discharge in SF/sub 6/ is simulated by using a model that combines both the physical and chemical aspects of the problem. The corona discharge is assumed to occur inside a wire-to-cylinder reactor filled with pure SF/sub 6/ at atmospheric pressure and ambient temperature. The chemical model of the corona includes both elementary plasma processes and chemical reactions between molecules and radicals. As result of the simulation, the radial distribution of electrons, ions and neutral species are predicted as a function of the applied voltage and current intensity.

Numerical modeling of negative corona discharge in dry air: the role or carbon dioxide

Negative corona discharge in a mixture of N2, O2 and CO2, in the same proportion as in dry air, is simulated by using a model that combines the physical and chemical aspects of the problem. The chemical model includes both elementary plasma processes and chemical reactions between molecules and radicals. The corona discharge is generated inside a wire-to-cylinder reactor and the steady radial distribution of electrons, ions and neutral species are predicted as a function of the radial distance to the wire.

Numerical modeling of S/sub 2/F/sub 10/ generation by negative corona discharge in SF/sub 6/ [gaseous insulation]

The negative corona in SF/sub 6/ is numerically simulated with a simple one-dimensional model that combines the basic aspects of the physics and chemistry of the electrical discharge. The chemical kinetics model includes charged and neutral species, and particular attention is paid to the generation of S/sub 2/F/sub 10/ by the electrical discharge. The role of the electrode walls on the decomposition of S/sub 2/F/sub 10/ is investigated as well.