Study on laminar flame characteristics of H₂/CO/O₂/CO₂ mixtures at different preheating temperatures

The laminar flame characteristics of H₂/CO/O₂/CO₂ mixtures at different preheating temperatures were studied using the dual-chambered, pressure release type spherical flame device. The laminar flame speeds and the Markstein lengths of mixtures were obtained at different preheating temperatures (298~450 K) and CO₂ dilution ratios (50%~70%). The results indicated that the Markstein lengths decreased with increasing CO₂ dilution ratio, and increased with elevating preheating temperature. The thermal effect of CO₂ dilution was more important in CO₂-diluted flame. The chemical effects increased with increasing CO₂ dilution ratio and decreased with elevating preheat temperature at low CO₂ dilution ratio, but decreased with elevating temperature at high CO₂ dilution ratio.