EXPERIMENTAL SET-UP AND NUMERICAL SIMULATION OF A METHANE-LEAN OXYGEN DIFFUSION FLAME

This paper presents the performances of a post-combustion burner using as fuel the natural gas and as oxidizer a poor oxygen mixture. This burner, with a fuel flow, rate of 100 Nm(3)/h, represents a module in the construction of others high fuel flow rate burners. It is well known that the burner performances depend on the flame stabilization solution. As a result, three kinds of flame stabilizers with incorporated cooling system were considered: a) semicircle shape, with enlargement contrary to the flow direction; b) semicircle shape, with enlargement in the flow direction; c) "V" shape type, with enlargement in the flow direction. The numerical simulation revealed that, among them, the last one represents the best choice From the point of view of flow, combustion, irreversibility and carbon monoxide emissions. The experimental tests were performed at U.P.B. on a pilot boiler of 1 MW, whose burner was equipped with "V" shape type flame stabilizer. They showed that a stable and a reduced length flame were obtained. Experimental data have also revealed that the presence of cooling air reduces the emissions of CO.