Stability limits and efficiency of swirl-can combustor modules burning natural gas fuel

Individual swirl-can combustor modules burning natural gas fuel were evaluated for combustion efficiency, stability, and flame length.T e s t s were performed at ambient temperature and pressure with modules of various cone angles and a constant exit diameter of 2.25 in.(5.72 em).Results showed a significant increase in combustion efficiency and stability, accompanied by a shorter flame length, for modules with wider cone angles.Decreasing the inlet orifice diameter from 0.75 t o 0.60 in.(1.91 to 1.52 cm) increased combustion efficiency for all modules tested.The decrease in inlet orifice diameter had little effect on the general shape of a module's lean and rich blowout curves but did decrease the fuel-air ratio value at the point of maximum blowout velocity.