用风口耗氧量来评估某些高炉操作制度

Evaluation of some blast furnace operation system with tuyere oxygen consumption

从低碳炼铁的角度研究高炉采取的各种操作制度的合理性非常必要。用Rist模型和风口耗氧量来评估增加渣量、提高炉腹煤气量、高富氧高湿度、低硅冶炼等操作制度。研究了增加渣量不仅要增加炉渣的熔化热,而且由于风口耗氧量的增加,将提高直接还原度,提高燃料比。高富氧高湿度冶炼,由于水分解需要消耗碳素,同时附加了热量消耗,使风口耗氧量增加;唯有改善炉身效率,增加间接还原,充分利用炉内煤气热能和化学能,才能补偿风口耗氧量引起的负面影响。目前中国高炉的炉身效率普遍偏低,而低硅冶炼应在提高煤气利用率与低燃料比的基础上进行才能发挥效果。由此提出在种种操作制度下需要关注的方面,供操作者参考。

It′s necessary to study the reasonability of various operation duties of blast furnace from the perspective of low carbon ironmaking.The operation system including slag volume increase,bosh gas volume increase,high oxygen enrichment,high humidity and low silicon producing is evaluated with Rist model and tuyere oxygen consumption.When increasing the slag volume,the melting heat of slag should be increased,and also the tuyere oxygen consumption will be increased,which can result in the improvement of the direct reduction and fuel ratio.In the operation of high oxygen enrichment and high humidity,the tuyere oxygen consumption will be increased,which is caused by the consumption of carbon and additional heat for water splitting.To compensate the negative influence of the tuyere oxygen consumption,the BF stack efficiency has to be optimized so that the indirect reduction can be increased and the gas thermal energy and chemical energy can be fully used.Currently,the Chinese BF stack efficiency is generally low,while low silicon smelting should be applied on the condition of high gas utilization rate and low fuel ratio.Therefore,several aspects which should be noticed in different operation system are proposed to provide references for the operators.