Preliminary investigation by experiment on the premixed MILD combustion of C_3H_8 in a cylindrical furnace

摘要

This paper reports the experimental results of the premixed MILD combustion of propane (C_3H_8) in a cylindrical furnace with a single jet burner. Cases under different inlet diameters, thermal inputs and equivalence ratios are investigated. Results show that premixed MILD combustion can be established over wide ranges of inlet velocity and equivalence ratio. However, it becomes unstable when the inlet velocity is less than 20 m/s. Infurnace measurements indicate that temperature and species distribute closely uniformly under premixed MILD combustion. Relatively low exhaust NO emissions (< 50 ppm) are achieved. Under current experimental conditions, the relationship between the NO emission and mean temperature of the exhaust gas may be considered approximately linear. This case is quite similar to the combustion in a well-stirred reactor, whose NO emission also has a nearly linear relationship with the exhaust temperature over the range of 1100～1500K.