AN INVESTIGATION OF THE INFLUENCE OF FLUIDICS INSERTION TECHNIQUE ON ACETYLENE/ARGON GAS ADDITIVES TO LPG ON THE TURBULENT LEAN PREMIXED FLAME CHARACTERISTICS FOR AN EV BURNER

摘要

A scries of experiments were performed on a vertical EV burner with a constant coflow air of 873 L /min to generate turbulent lean premixed flow in order to study the impact of the addition of Acetylene/Argon mixture to the liquefied petroleum gas (LPG) on the temperature field and flame structure. The fluidics mechanism was inserted at a fixed position inside the entry section of the EV burner assembly. The flow rates of fuel (LPG/ C_2H_2/ Ar) and air were measured using calibrated rotameters. The different volume ratios of the fuel constituents (at a specified fuel flow rate) were admitted via three solenoid valves at the entry section of each stream prior to mixing and monitored using a labview program. The axial temperature profiles at different operating conditions were measured using a bare wire Pt-Pt -10% Rh (type S) thermocouple of wire diameter 250 μm. Flame images were obtained-before and after fluidics insertion- using a high resolution Canon 6D 20MP digital camera. The selection of the different considerated cases was based on flame stability. The experimental program aims at identifying and analyzing the changes in flame characteristics (flame length, axial profiles of mean gas temperature, NO_x concentration and overall combustion efficiency) resulting from the insertion of fluidics while considering different proportions of the fuel constituents) (including pure LPG , as a reference case). In all experiments flame stabilization was ensured. The results obtained indicate the following: it was noticed that in most cases of pure LPG only , and other mixtures the images shows increase in both the length and luminosity of the flame as a result of higher degrees of swirl due to the fluidics insertion while the temperature profiles of the different flames were changed. It was indicated that Nox trend was decreased by 52% while the combustion efficiency was improved by 2.5%.