Optimization of DBD Reactors for Ozone Generation

Ozone generation efficiency is often used as an indictor to evaluate the performance of DBD reactors. This study aims to provide a general guideline for designing cylindrical DBD reactors with better performance based on the ozone generation efficiency. In addition to experiments, a numerical model is developed in this study. Specific energy density, defined as the ratio of deposited power to flow rate, is an important parameter for plasma. Two breakdown mechanisms are adopted to predict the breakdown voltage of a specific reactor to determine the theoretical deposited power. The results of experiments and simulation show good consistency, verifying the validity of the modeling. Based on the experimental and simulation results, smaller reactor and larger inner electrode will achieve better energy efficiency at the same specific energy density in that the mean electron energy is higher so that most of the energy can be used to produce atomic oxygen, the precursor for ozone formation. However, for reactors with small diameters, there exists an optimum inner electrode diameter. The influence of dielectric thickness is also investigated. Increasing the dielectric thickness of a specific reactor results in higher breakdown voltage, leading to lower deposited power and ozone concentration at a fixed applied voltage.