Combustion Characteristics of a Tubular Flame Burner for Methane.

Abstract

Combustion characteristics of a tubular flame burner, which has been developed previously for propane, have been investigated with using methane as a fuel. The results show that the combustion characteristics for methane are almost the same as those for propane. Namely, (1)the equivalence ratio at the lean limit is about 0.5, (2)the wall temperature at the injection section is kept low, and (3)the burned gas temperature is uniform in the axial direction. However, (4)a tubular flame with a large laminar flame area of 0.24 m2 is obtained with lean mixtures, (5)the stable flame region in the fuel-rich side is very narrow, (5)the equivalence ratios at which the flame diameter, the flame length, and the flame temperature take their maxima or minima are shifted to 0.9, and (6)the volumetric burning rate becomes 50% less or more than the total mixture volume flow rate for the near lean- and rich-limit mixtures, although they agree well for the stoichiometric mixture.