Determination of the characteristics of combustion of gas fuels of variable composition in a niche stabilizer burner

Abstract

The results of experimental studies of the burning of ballast gases, which were a mixture of highly reactive propane-butane gas with air and carbon dioxide, were considered. The studies were carried out using a flat, hollow stabilizer with a width of 28 mm, which was flowed by an air stream on both sides. On both sides of the stabilizer, two niches deepenings with a length of 30 mm and a depth of 7 mm each were made in sequence according to the flow of air. Ballasted fuel of variable composition was supplied by perpendicular jets into the air flow from holes located on the walls of the first row of niche deepings. During the experiments, the concentration of impurities in the high-reaction fuel varied from 0% (propane-butane) to 100% (no fuel). Studies have shown that with an increase of the amount of impurities in the fuel, the length of the torch gradually decreases, as well as the temperature of the combustion products and the content of nitrogen oxides. When a certain concentration of impurities in the fuel is reached, a combustion failure occurs. The dependence of flame stability from the relative content of impurities in the fuel was established. To stabilize combustion, pure high-reactivity fuel (propane-butane) was fed into the air flow from the walls of the second row of niches deepenings from a separate collector. The supply holes for stabilizing high-reaction fuel are offset by half a step relative to the supply holes for ballasted fuel. So, jets of low-reactivity fuel of variable composition pass between high-temperature torches of high-reactivity fuel and as a result of which ignition and stabilization of combustion of low-reactivity fuel occurs, regardless of the composition of the latter.The adopted combined gas supply scheme provides an opportunity to regulate the fuel consumption in the niches and thus to regulate the burner power.