Experimental investigation of the pressure influence on flame structure of fuel-rich oxy-fuel methane flames for synthesis gas production

摘要

The structure of fuel-rich CH4/O-2-flames at equivalence ratios in the range of 2.5 phi 2.9, a preheating temperature of TP = 573 K and pressure in the range of 1 bara p 5 bara was studied experimentally and compared with numerical results using detailed reaction mechanisms. Two measurement techniques, invasive gas sampling (GC/MS) and optical in-situ TDLAS measurements (tunable diode laser absorption spectroscopy), were used to determine temperature and major combustion species (CH4, O-2,O- H-2, H2O, CO and CO2). The results showed that the composition of the synthesis gas in the post flame zone strongly depends on phi, while p has only a minor influence. Furthermore, the influence of phi andp on the phenomena of super-adiabatic flame temperatures (SAFT) was determined by experimentally and numerically investigating temperature and H2O concentration. The results showed similar trends as for the synthesis gas composition: a strong dependence of phi and a minor influence of pressure on the degree of significance of the SAFT phenomena.