Experimental and numerical study on the influence of N2/H2 on the laminar combustion characteristics of syngas premixed flames

Abstract

This paper primarily analyzes the influence of N2 and H2 content on the laminar combustion characteristics of low calorific value syngas, using a constant-volume combustion bomb to measure the laminar combustion velocity (SL) of the fuel and compare it with five commonly used mechanisms. The study reveals that higher N2 content significantly reduces the SL of CO/CH4/CO2 mixed fuels, primarily due to a general decrease in the mole fractions of key intermediates and net reaction rates. Increasing H2 content leads to an increase in the SL of CO/CH4/CO2/N2 mixed fuels. The thermal effect becomes increasingly prominent with the elevation of H2 content, while the proportion of thermal effect initially decreases and subsequently increases as the equivalence ratio rises. With the increase in N2 content, the mole fraction of NO experiences a significant decrease, and the rate of decline in thermal NO production is even faster. Conversely, with the increase in H2 content, the rate of rise in non-thermal NO generation is faster, and the mole fraction of NO tends to increase.