富氧条件对低热值燃气烧结点火的影响

针对低热值燃气燃烧温度低导致烧结点火质量差的问题,采用描述碳氢火焰燃烧的化学动力学详细机理GRI-Mech3.0对低热值燃气的燃烧过程进行模拟;研究了富氧条件对低热值燃气燃烧温度、烟气氧浓度和燃烧速率的影响;开展了低热值燃气富氧点火技术的工业化试验。研究结果表明,采用富氧空气作为助燃剂可以显著提高低热值燃气点火温度,改善点火效果;当助燃风氧体积分数提高至0.23时,纯高炉煤气点火效果可以提高至与采用空气加混合煤气的点火效果相等;进一步提高助燃风氧含量使得烧结点火能耗相应降低,表层烧结矿质量相应增加。工业化试验表明,富氧点火是实现低热值燃气高质低耗点火的有效途径,对降低烧结工序点火能耗有积极意义。

Effect of oxygen enriched conditions on sintering ignition of low calorific value gas

Aiming at the problem of poor ignition quality caused by low combustion temperature of low calorific value gas, the combustion process of low calorific value gas was simulated by GRI-Mech3.0, which was a detailed mechanism describing the chemical kinetics of hydrocarbon flame combustion. The effects of oxygen enriched conditions on combustion temperature, oxygen concentration and combustion rate of low calorific value gas were studied. The industrial test of oxygen enriched ignition technology for low calorific value gas was carried out. The results showed that using oxygen rich air as combustion supporting agent can significantly improve the ignition temperature of low calorific value gas and improve ignition effect. When the oxygen volume fraction of combustion supporting air was increased to 0.23, the ignition effect of pure blast furnace gas could be improved to the same as that of using air and mixed gas. Further increasing the oxygen content of combustion supporting air could reduce the ignition energy consumption of sintering, and increase the quality of surface sinter accordingly. Industrial test shows that oxygen enriched condition is an effective way to realize high quality and low consumption ignition of low calorific value gas. It has positive significance to reduce ignition energy consumption in sintering process.