Enhancement of Propane Flame Stability by Dielectric Barrier Discharges

Non-thermal plasmas have recently found novel applications in improving fuel combustion. Typical electron temperatures in such plasmas are of order a few electron volts. Such electrons are sufficient to break down fuel molecules and to produce free radicals which may significantly affect combustion efficiency. In this work, we use a dielectric barrier discharge (DBD) to activate propane (C3H8) fuel before it is mixed with air and ignited. The use of activated propane enables us to operate combustion in very lean-burn conditions; for 0.2 lpm propane, air flow was 38 lpm, compared with an air flow of 26 lpm in the absence of a plasma. A residual gas analyzer (RGA) measures the decomposition products of the propane discharge, indicating that atomic and molecular hydrogen are produced in the plasma and that their concentrations depend on the DBD energy density. Based on the observations discussed in this work, we have shown that by activating propane, the DBD increases combustion stability.