Combustion characteristics of partially premixed flames with varying compositions of CH₄/C₃H₈/N₂ mixed fuels

In this study, an investigation into the combustion characteristics of varying gas compositions with CH₄-C₃H₈-N ₂ mixed fuels described natural gas is performed experimentally and numerically. For this, flame lifting and NO_x and CO concentrations are experimentally observed and measured using a domestic partially premixed appliance such as a gas-oven with various the specific gravity (SG) and the Wobbe index (WI) values. In addition, the numerical simulation for partially premixed flames is performed using OPPDIF code with detail reaction mechanism to understand NO_x and CO emission characteristics. As experimental results, the flame is stable, and the CO and NO_x concentrations increase when the WI and SG values are increased. Specifically, the behavior of the flame lifting change between WI values of 52.0 MJ/Nm³ and 53.0 MJ/Nm³. As numerical results, peak CO concentration increases when the value of the SG increases for the same WI value and the value of WI increases for the same SG value. For peak NO concentration, NO concentrations are almost constant.