Studying Of Stabilization Of Turbulent Jet Diffusion Flame By Experiment

Studying of stabilization of turbulent jet flame in regular lifting height change by experimentation is not only conducive to enhancing understanding of turbulent combustion theory, and also to promote the industrial design and retrofit of the combustion chamber. In the experiment, the axisymmetric burner of Jet with co-flow was designed to simulate the actual combustion flame in chamber, the burner can provide actual combustion chamber in the research of turbulent jet flame standing in the dilution of jet fuel, high temperature product return, air wake (normal temperature, high temperature), and other conditions of actual combustion.On the experiment platform, lifted height, blowout and blow-off of flame in the turbulent jet flame with dilution, promise change with different velocity of jet, the degree of dilution and the influence of ambient air on the lifted height of flame, then effect of high temperature products of premixed combustion on jet flame. The results indicate that the lifted height of free jet flame in turbulent combustion is grow linearly with the velocity of jet, and with increasing the mole fraction of nitrogen dilution linear slope turn into sharp;it is difficult to blowout and blow-off when the mole fraction of fuel in the mixed jet gas (methane or propane mixed with nitrogen) increase, blowout and blow-off of the jet flame need larger Reynolds number compared with dilution; The lifted height of flame increases with co-flow velocity in turbulent jet combustion with ambient air co-flow, when the wake velocity less than0.3m/s it will less affected by the lifted height. Extraordinary, the lifted height increased linearly with the wake velocity when it is more than0.3m/s; when the speed of jet is greater than the20m/s, wake effect on the flame height decreased. Comparing the influence of co-flow and dilution, when the jet velocity is less than30m/s, lifting height more sensitive to the dilution; and when it is greater than30m/s, flow velocity change lifted height of flame greater.co-flow of high temperature with the premixed combustion products can provide a stable combustion environment for jet combustion with radial distance50mm,45d axial distance range, wake temperature1300K to1500K, low concentration of oxygen (4.58%); As the products of premixed combustion has high temperature plays role of co-flow, without cooling and heat insulation measures in jet pipe, the fuel temperature out of it will be preheated to higher than the point of ignition, because of this and the high temperature wake, flame attached to the nozzle, come to increase jet velocity it will uplift slightly and wherever large of the velocity at normal temperatures and pressures it never be blow-off.