The reactive species production and ignition of the hydrogen-oxygen and hydrogen-air mixtures by RF DBD

Abstract

Summary form only given. The reactive species production is very important for multitude of applications, such as biological sterilization and healing, plasma assisted ignition and combustion, surface treatment and destruction of the harmful substances and pollutions. The ignition of the air-fuel mixtures has received considerable attention in the recent years. The results various studies [Starikovskaia, S.M., 2006; Zy Yin, et al., 2011] within the last decades show that chemical chains can be artificially initiated by low temperature plasma of gas discharges. The present paper reports the results of two-dimensional (2D) modeling and optimization of the radio frequency dielectric barrier discharges (RF DBD) under atmospheric pressure as radicals and gas heating sources. The simulations were carried out in the following gas mixtures H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> . The simulations of the RF DBD show that this type of the discharge has a number of advantages and it may be used for ignition of air-fuel mixtures. Both the reactive species production and gas heating are very high here. The driving voltage frequency used in this discharge is 1.76MHz. The discharge in such conditions is not classical RF discharge like it is under low and intermediate pressures. It resembles the classical DBD under intermediate pressure. The discharge consists of many breakdowns that occur each half period. The applied voltage modifications were tested. First the pulsed RF DBD was tested. The periodic applied voltage switching off results in low gas heating while the reactive species decreases only two times. After that the dual frequency discharge was tested. The second frequency of kilohertz range was added. The addition of the second lower frequency also results in lower gas heating and the same radicals production. Finally the frequency modulated RF DBD was tested. The radicals production is an order of magnitude higher here. Although the gas heating is almost the same as in ordinary RF DBD. Thus the applied voltage modifications allow controlling gas heating and radicals production in the discharge.