One-dimensional mathematical model for oxygen blast furnaces with top gas recycling based on heat transfer and reaction kinetics
-
摘要: 結合風口回旋區燃燒和爐外煤氣預熱、脫除和循環的平衡關系,建立了氧氣高爐一維氣固換熱與反應動力學模型,并采用傳統高爐的運行和解剖數據對模型進行了驗證分析.通過模型研究了氧氣含量和上部循環煤氣流量對氧氣高爐爐內過程變量的影響規律.結果表明:氧氣含量偏低和上部循環煤氣流量不足時,會降低鐵礦石還原效果,爐渣內出現大量未還原鐵氧化物;氧氣含量和上部循環煤氣流量的提高可以有效提高爐內CO含量和鐵礦石還原速度,但提高上部循環煤氣流量會大幅提升爐頂煤氣溫度,增大熱量損失.與傳統高爐相比,氧氣高爐內CO含量提高1.0~1.5倍,爐內氣體還原性更強;鐵礦石還原完成位置提高1.49 m,全爐還原反應速度更快;直接還原度降低55.2%~79.2%,爐內直接還原反應消耗的碳量更少.Abstract: A one-dimensional mathematical model based on heat transfer and reaction kinetics was developed for an oxygen blast furnace and was validated with the operating conditions and dissected data of a conventional blast furnace. The influence of oxygen concentration and upper gas volume on the smooth operation and process variables of the oxygen blast furnace was investigated by the model combined with coal combustion at tuyeres and top gas balance for separation and preheating. When the oxygen blast furnace with top gas recycling is of low oxygen concentration and upper gas volume, the reduction of iron ore is worsen and massive unreduced iron oxide comes into slag. In the oxygen blast furnace with top gas recycling, oxygen concentration and upper gas volume have significant effect on the temperature, reducing ability of gas and reduction rate. A comparative analysis of the conventional blast furnace and the oxygen blast furnace with top gas recycling show that the oxygen blast furnace has a higher reducing ability of gas (1.0 to 1.5 times higher for CO content), faster reduction rate (1.49 m higher for the position of ore reduction), and less direct reduction (55.2% to 79.2% less for direct reduction degree).
-
Key words:
- blast furnaces /
- mathematical models /
- gas /
- recycling /
- steady state /
- heat transfer /
- reaction kinetics
-

計量
- 文章訪問數: 243
- HTML全文瀏覽量: 33
- PDF下載量: 10
- 被引次數: 0